a comparative evaluation of the combined occluding …

i

“A COMPARATIVE EVALUATION OF THE COMBINED OCCLUDING EFFECT

OF SODIUM FLUORIDE VARNISH AND ER:YAG LASER IRRADIATION ON

DENTINAL TUBULES-A CONFOCAL LASER SCANNING MICROSCOPE AND

SCANNING ELECTRON MICROSCOPE- AN IN VITRO STUDY.”

By

Dr. SAHIL R. KAWLE

Dissertation Submitted to the

Rajiv Gandhi University of Health Sciences, Karnataka, Bangalore

In partial fulfillment of the requirements for the degree of

MASTER OF DENTAL SURGERY

In

Conservative Dentistry and Endodontics

Under the guidance of

Dr. PRAHLAD A. SARAF, M.D.S.

DEPARTMENT OF CONSERVATIVE DENTISTRY AND ENDODONTICS

P.M.N.M. Dental College and Hospital, Bagalkot,

Karnataka-587101

2016- 2019

Scanned by CamScanner

LIST OF ABBREVIATIONS

ABBREVATIONS FULL NAME

CDH Cervical Dentine Hypersensitivity

CFFM Computerized Fluid Filtration Method

CLSM Confocal Laser Scanning Microscope

CO2 Carbon Dioxide Laser

CSPS Calcium Sodium PhosphoSilicate

oC Degree Celsius

DH Dentinal Hypersensitivity

DL Diode Laser

Er Cr:YSGG Erbium, Chromium doped Yttrium, Scandium, Gallium and

Garnet

Er:YAG Erbium doped Yettrium Aluminium Garnet

ESEM Environmental Scanning Electron Microscope

Fig. Figure

GaAlAs Galium Aluminium Arsenide

HAP Hydroxyapatite

He-Ne Helium Neon Laser

Hz Hertz

µm Micrometer

Min Minutes

Mm Millimeter

MJ Mega Joules

n-Hap Nano-Hydroxyapatite Agents

NaF

Sodium Fluoride

Nd:YAG Neodymium doped Yettrium Aluminium Garnet

% Percentage

P Probability Value

Sec. Seconds

SEM Scanning Electron Microscopy

SPSS

Statistical Package For Social Science

VAS Visual Analogue Scale

LIST OF TABLES

Table No. CONTENTS Page No. 1. Normality of tubules diameter of dentinal tubules scores by Kolmogorov

Smirnov test.

27

2. Normality of depth of penetration of die in dentinal tubules scores by

Kolmogorov Smirnov test.

27

3. Summary of tubules diameter scores in four study groups (A, B, C and D)

27

4. Comparison of four study groups (A, B, C and D) with respect to mean

tubules diameter scores by one way ANOVA

27

5. Pair wise comparisons of four study groups (A, B, C and D) with respect

to mean tubules diameter scores by Tukeys multiple posthoc procedures

28

6. Comparison of two study groups (E and F) with respect to mean depth of

penetration of die in dentinal tubules scores by independent t test

28

LIST OF GRAPHS

Sl.No. Contents Page no.

1 Comparison of four study groups (A,B,C and D) with respect

to mean of tubules diameter of dentinal tubules scores.

29

2 Comparison of two study groups (E and F) with respect to

mean depth of penetration of die in dentinal tubules scores

30

LIST OF FIGURES

S.No. Contents Plate No. 1. Teeth specimens for study 1

2. Tooth section of specimens 1

3. Armamentarium 2

4. Er:YAG Laser 2

5. Tooth Sectioning 3

6. Sodium Fluoride varnish Application 3

7. Rhodamine B dye Application 3

8. Er:YAG Laser Application 3

9. Scanning Electron Microscope 4

10. Confocal Laser Scanning Microscopy 4

11. SEM images 5

12. CLSM images 5

xii

ABSTRACT

“A COMPARATIVE EVALUATION OF THE COMBINED OCCLUDING EFFECT

OF POTASSIUM FLUORIDE VARNISH AND ER:YAG LASER IRRADIATION

ON DENTINAL TUBULES-A CONFOCAL LASER SCANNING MICROSCOPE

AND SCANNING ELECTRON MICROSCOPE- AN IN VITRO STUDY.”

BACKGROUND AND OBJECTIVE: Dentin hypersensitivity (DH) is one of the most

frequent problems causing patients. Various treatment modalities have been proposed for

dentin hypersensitivity, but to date, no single agent or form of treatment has been found

effective. The Er:YAG lasers have promising potential for the treatment of dentine

hypersensitivity. Lasers in combination with sodium fluoride varnish appear to show better

efficacy compared to either treatment modality alone. Thus the aim of this in vitro study was

to compare and evaluate the combined occluding effect of sodium fluoride varnish and

Er:YAG laser irradiation on dentinal tubules through scanning electron microscope and

confocal laser scanning microscopy.

MATERIAL AND METHOD: Forty five extracted maxillary premolar teeth were included

in this study. 3-mm-thick horizontal slice was prepared from the cemento-enamel junction of

each tooth using a slow-speed diamond saw. Each slice was transversely separated into two

halves as buccal and lingual 90 samples was obtained and these samples was randomly

divided into six equal groups. Groups A, B, C and D was used for the evaluation of tubule

occlusion with Scanning Electron Microscope (SEM). Groups E and F was separated for

dentin permeability with Confocal Laser Scanning Microscopy (CLSM).

RESULTS: Results of present study reveals that SEM analysis presented occlusion and

narrowing of dentinal tubules in all treatment groups, but more prominent occlusion was

observed in the combined treatment group. CLSM shown less dye penetration for combined

Er:YAG laser and sodium fluoride (NaF) varnish than alone treatment modality. Intergroup

comparisons regarding the tubule diameters and the number of the open dentinal tubules per

100 µm2 revealed statistically significant difference in favour of combined group ( p < 0.05).

The difference between single effects of Er:YAG laser and NaF in all parameters were found

statistically significant.

CONCLUSION: Within the limitation of this study of this in vitro study,it can be concluded

that, all the treatment modality for reducing dentinal hypersensitivity were effective for the

xiii

occlusion and narrowing of dentinal tubules. The more prominent occlusion was observed in

the combined treatment of Er:YAG laser and sodium fluoride varnish on dentinal

hypersensitivity. Therefore, whether used alone or in combination of Er:YAG laser and

sodium fluoride varnish, Er:YAG laser irradiation is effective for the treatment of dentinal

hypersensitivity.

KEYWORDS: Dentin hypersensitivity, Confocal Laser Scanning Microscopy, Er:YAG

laser, Scanning Electron Microscope, Sodium Fluoride varnish.

Introduction

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INTRODUCTION

Dentine Hypersensitivity (DH) is a common occurrence and a concern among

patients. Currently, DH represents a challenging problem to the dental profession, in

view of a substantial increase in the population during the late 20th century.

According to the ‘‘hydrodynamic theory’’ movements of fluid within exposed

dentinal tubules are responsible for the stimulation of pulpal mechano receptors. It is

characterized by short, sharp pain arising from exposed dentin in response to stimuli,

typically thermal, evaporative, tactile, osmotic, or chemical and which cannot be

described to any other dental defect or disease. Many factors, such as abrasion,

erosion, attrition and gingival recession following scaling and root planing (SRP).

Some other factors, including age, sex, occlusion incompatibility, oral pH, local

bacterial plaque and the level of the patient’s oral health can also seriously affect

dentinal hypersensitivity1.

Currently there are at least two recognized mechanisms of action of

desensitizing agents: (1) blocking fluid movement by occluding tubules and (2)

blocking pulpal nerve activity by altering the excitability of the sensory nerves. A

wide variety of chemical and physical agents have been used for the treatment of the

dentin hypersensitivity such as anti-inflammatory agents (corticosteroids); protein

precipitants (formaldehyde, silver nitrate, strontium chloride hexahydrate); tubule

occluding agents (calcium hydroxide, potassium nitrate, sodium fluoride); and tubule

sealants (resins and adhesives).2

There are several methods used for the treatment of DH. These methods

include instructions for proper brushing, dietary advice, occlusal adjustment, use of

desensitizing products, irradiation of low-power or high-power lasers, the use of

adhesive systems and adhesive restorations. A product containing the combination of

an aqueous solution of 35% hydroxyethyl methacrylate and 5% glutaraldehyde

(Gluma desensitizer, Heraeus Kulzer GmbH) is considered to be an efficient

desensitizing agent. Dentinal tubules are inherently blocked by the glutaraldehyde and

this counteracts the hydrodynamic mechanism that gives rise to DH. Nano-

hydroxyapatite (n-Hap) agents, generally considered among the most biocompatible

and bioactive materials available in dentistry, which has the potential to repair dental

enamel are effective in occluding dentinal tubules are also used in treatment of DH.3

Introduction

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Calcium sodium phosphosilicate, known by the trade name NovaMin, contains

calcium, sodium, phosphate and silica and is initially used for bone regeneration.

NovaMin has also been used as a desensitizing agent for occluding dentin tubules.

NovaMin-containing agents, including NUPRO Sensodyne Prophylaxis Paste with

NovaMin (with and without fluoride (NPP)), which is used to reduce DH following

periodontal dental treatment, such as scaling-root planning.4

Synthetic hydroxyapatite (HAP) has been described as a biocompatible and

biomimetic compound which is able to reduce hypersensitivity and to potentially

enhance remineralization. Recently, toothpastes containing HAP have proved

clinically effective for treatment of DH. A particular crystalline zinc substituted

hydroxyapatite used for the treatment of DH was analyzed with various

physicochemical methods. Because of its particle size of about 200–400 nm, these

Hydroxyapatite crystallites are well suited to occlude open dentin tubuli. For testing

dentin permeability, different in vitro methods have been described, based either on

measuring the diffusion or the perfusion of marker substances through dentin before

and after material application, simulating a one-time use of a product or compound.

Hydroxyapatite as such interacts with saliva proteins forming the enamel pellicle due

to its high polarity. Many different salivary proteins can bind to the enamel surface,

e.g. proline-rich proteins, cystatins, statherins, histatins and others. Two mechanisms

of protein adsorption are reasonable, a direct mineral-protein interaction and a

protein-protein interaction.5

The Colgate Sensitive Pro-Relief daily paste which contains a Pro-Argin™

formulae (containing 8% arginine and calcium carbonate as well as 1450 ppm sodium

monofluorophosphate) and the Sensodyne Rapid Relief (containing 8% strontium

acetate and 1040 ppm sodium fluoride) as also used in the treatment of DH. Arginine

is a relatively recent addition to the dentine tubular occlusion technologies,whereas

strontium salts have been used in dentifrices for more than half a century. Clinical

studies show 8% arginine-based dentifrices reduce DH immediately and following 3

day and 8 week applications compared to control, 2% potassium nitrate or citrate and

1450 ppm sodium monofluorophosphate fluoride based dentifrices. Similarly, 8%

strontium based dentifrice in silica base reduces DH significantly compared to 1450

ppm sodium fluoride in silica base and an 8% arginine and 1450 ppm sodium

monofluorophosphate.6

Introduction

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An early in situ randomised control trial using dentine samples treated with

8% strontium acetate based dentifrice, showed a dentine surface deposit resistant to

water rinsing. In addition, 8% strontium acetate based dentifrices have shown

significant dentine tubular occlusion compared to 8% arginine, 5% potassium nitrate,

strontium chloride, fluoride,

1% and 3% polysaccharide and 1% phosphate salt based dentifrices, chlorhexidine

and water in vitro following acidic challenge. Although 8% arginine-based dentifrices

have demonstrated dentine tubular occlusion and resistance to an acid challenge

invitro there is some debate as to the robustness of the occlusion when faced with an

acidic challenge.6

Calcium sodium phosphosilicate (CSPS) is an ingredient found in a number of

professional use and over-the-counter dental products designed to provide relief from

DH. CSPS is a bioactive glass (CaO-Na2O-P2O5-SiO2) and was originally developed

as bone repair material in the early 1970s.CSPS has been reported to form a direct

bond with calcified tissue following exposure to an aqueous environment. Once in an

aqueous environment CSPS has been reported to undergo a series of chemical

reactions that result in an increase of the local pH to approximately 9. This creates an

environment suitable for silica release, formation of a porous silica gel surface and the

formation of calcium apatite.7

A reservoir of calcium and phosphate is formed beneath the silica gel and

these ions are released into the aqueous environment through the porous surface.

CSPS incorporated in dentifrice formulations has been reported to physically occlude

dentine tubules, increase dentine mineralization and provide relief from the pain of

DH. In vitro, in situ and clinical efficacy studies have demonstrated significant levels

of dentine occlusion and relief from dentine hypersensitivity, following treatment

with CSPS containing dentifrices.7

Sodium fluoride gel (NaF), which belongs to the tubule-occluding agents

family is the most commonly used agent by clinicians. This agent’s primary

mechanism relies on the mechanical occlusion that is accomplished by precipitation

of insoluble calcium fluoride crystals within the tubules without adhesion and thus

this agent cannot resist the stresses of the oral environment and degrades over time.8

In recent years new developing technical modalities lasers and topical ozone

gas have been proposed for the treatment of DH. Laser systems such as He-Ne, diode,

Co2, Nd:YAG and erbium lasers (Er,Cr:YSGG,Er:YAG) have been used as potential

Introduction

[Type text] Page 4

treatment alternatives. Among these laser systems, Er:YAG laser has drawn attention.

Er:YAG laser with 2.94 µm wavelength is highly absorbed in water and less in

hydroxyapatite and is considered to be one of the low-risk lasers without producing

thermal effects. The mechanism behind the laser’s effect on dentine hypersensitivity is

thought to be laser-induced occlusion, narrowing of dentinal tubules or direct nerve

analgesia. The efficacy of laser in dentinal hypersensitivity therapy can be related to

both high power, causing coagulation of fluids contained in the dentinal tubules

having a melting effect with crystallization of dentine inorganic component, and the

direct action of laser to low power on nerve transmission with suppression of the pulp

nociceptive nervous fibers, blocking diffusion of pain to the central nervous system.9

The Er:YAG laser appears to be suitable for successful reduction of dentine

hypersensitivity. Its thermomechanical ablation mechanism and the high absorption of

its wavelength by water may lead to a decrease in dentinal fluid movement by

evaporating the superficial layers of dentinal fluid. To increase the effectiveness of

dentin hypersensitivity treatment researchers postulated combination treatments, such

as lasers and chemical agents. Combination of Er:YAG laser and 5% sodium fluoride

(NaF) varnish seemed to show efficacy when compared with either treatment alone, in

treating dentine hypersensitivity.10

The erbium laser family, including the Er;Cr:YSGG laser, is well-known for

its dental hard tissue ablation ability. This phenomenon is mostly attributed to high

absorption in the bonded water content of the crystallized structure of the tooth, which

leads to abrupt expansion and subsequently explosion of dental hard tissue.10

It has been indicated in the literature that when Er:YAG laser was applied with

lower than the ablation thresholds of dental hard tissues, it was supposed that Er:YAG

laser evaporated the superficial layers of the dentinal fluid and produced a decrease of

the rate flow thereby reducing sensitivity a decrease of the rate flow thereby reducing

sensitivity.10

Aims And Objective

[Type text] Page 5

AIMS AND OBJECTIVE

The aim of this in vitro study was to compare and evaluate the combined occluding

effect of sodium fluoride varnish and Er:YAG laser irradiation on dentinal tubules

through scanning electron microscope and confocal laser scanning microscopy.

Review Of Literature

[Type text] Page 6

REVIEW OF LITERATURE

An in vitro study was conducted by Ogul L et al, to evaluate the in vitro

effects of Er:YAG laser and an in-office desensitizing paste alone or in combination

by using scanning electron microscopic (SEM) analysis. Forty dentine specimens

obtained from freshly extracted impacted third molars were included and divided into

four groups. Group I served as the control, whereas Group II, Group III and Group IV

recieved Er:YAG laser, a desensitizing paste (DP) containing 8% arginine and

calcium carbonate and DP + Er:YAG laser in combination, respectively, evaluated

under SEM which presented occlusion and narrowing of dentinal tubules in all

treatment groups, but more prominent occlusion was observed in the combined

treatment group. Intergroup comparisons regarding the tubule diameters and the

number of the open dentinal tubules per 100 µm2 revealed statistically significant

difference in favor of combined group. The difference between single effects of

Er:YAG and DP in all parameters were found statistically non significant.

An in vitro study was conducted by Gholam Ali Gholami et al is aimed to

evaluate the occluding effects of Er;Cr:YSGG, Nd:YAG , CO2 and 810-nm diode

lasers on dentinal tubules. Fifteen human third molars were collected and ground-

sectioned vertically on the buccal and lingual surfaces to yield two dentin disks of 2-

mm thickness. Then, four sites for laser irradiation and one control site were marked

in the cervical areas of the dentin disks. Before laser application, specimens were

exposed to a 14% EDTA solution to expose dentinal tubules and were then evaluated

by scanning electron microscopy (SEM). The tubules’ entrance diameters were

determined by ‘‘scale-bar’’ software, which is specifically designed for SEM. The

mean diameters for the tubules were then estimated for each site. The mean dentinal

tubule entrance diameters for Er;Cr:YSGG, 810-nm diode, CO2 and Nd:YAG, were

1.73, 3.27, 2.10 and 1.64 microns, respectively, compared with 3.52 microns before

laser irradiation. However, tubular diameter reduction in all laser groups was found to

be statistically significant and thus concluded Nd: YAG, Er; Cr: YSGG, and CO2

lasers, through their ability to melt peritubular dentin, can occlude dentinal tubules

partially or totally and therefore reduce patients’ hypersensitivity symptoms. The 810-


[Type text] Page 7

nm diode laser sealed tubules to a far lesser degree, with negligible effects on

desensitization.

An in vivo study was conducted by Reza Birang et al, to evaluate the

comparative effect of Nd:YAG laser and Er:YAG laser on human teeth

desensitization. A group of nine patients with a total of 63 chronic hypersensitive

teeth were selected and were randomly allocated into three groups. Group 1, Nd:YAG

laser, group 2 Er:YAG laser and group 3 serves as control group without any

treatment. Assessment of pain was performed by a visual analogue scale (VAS) after

stimulation of sensitive tooth by using the sharp tip of an explorer. This test was

performed before treatment, immediately after that and at 1, 3 and 6-month intervals

after treatment by one blinded examiner. Analysis of VAS score between the three

groups at the time of treatment did not show any significant difference. However, by

using repeated-measurement analysis of variance test, significant differences were

seen in the three groups between before-treatment VAS score and after treatment.

This statistically significant difference in the control group demonstrated a placebo

effect. However, the effect of using Nd:YAG and Er:YAG lasers was stronger than

this placebo effect, so that after removing the effect of the placebo, differences

immediately after, 1,3 and 6 months post treatment between all three groups still were

statistically highly significant. Compared to the Er:YAG laser group, using Nd:YAG

laser resulted in a significant reduction of VAS score at each follow-up examination.

Although using Nd:YAG and Er: YAG laser in desensitization of hypersensitive teeth

showed a placebo effect limited to a short time, results of this study demonstrated that

both of these lasers have an acceptable therapeutic effect. The observed effects

seemed to last for at least 6 months. It was concluded that Nd:YAG laser is more

effective than Er:YAG laser in reduction of patients’ pain.

An in vitro study was conducted by Gokser Cakar et al, to evaluate the

occluding effect of erbium:yttrium-aluminum-garnet (Er:YAG) and carbon dioxide

(CO2) lasers as mono therapy and in combination with topical fluoride gel on human

dentinal tubules by scanning electron microscopic (SEM) examination. Thirty-six

dentine specimens with exposed dentinal tubule orifices were included in this study.

The samples were divided into six groups. Group A served as controls, group B was

treated with 2% sodium fluoride (NaF) gel alone, groups C and D were irradiated with


[Type text] Page 8

Er:YAG and CO2 lasers, respectively and groups E and F received NaF gel plus

Er:YAG and CO2 laser irradiation, respectively. Under SEM analysis, numerous

exposed, normally-structured dentinal tubule orifices were seen in the control group.

Some narrowing of the exposed tubule orifices was seen in group B. A melted,

irregular surface structure with small peaks was observed in group C. The surface of

group D also had a melted appearance, but a fibrillar deformation. However, the

surface morphologies seen were remarkably different in groups E and F. While the

tubule orifices were obviously occluded but depressed into craters in group E, the

surface structure of group F primarily showed a smooth appearance. In terms of

numbers and diameters of open dentinal tubules, there was no significant difference

between the laser-alone and combination groups, whereas the difference was found to

be significant when the control and NaF groups were compared with each other and

the remaining laser-alone or combination groups. The dentinal tubules in all laser

groups were occluded after laser irradiation, but more marked occlusions were

observed when laser and NaF gel were combined.

An in vitro study was conducted by Hare Gursoy et al, to evaluate the

occluding effect of topical gaseous ozone application and Er:YAG laser on human

dentine tubules by scanning electron microscopic (SEM) analysis. Twenty-four

dentine specimens were divided into three groups. Group I, including specimens

treated only with citric acid, served as the control. Group II was treated with Er:YAG

and Group III received only topical gaseous ozone application. Diameters and the

number of open dentinal tubules per 100 µm2 were counted from SEM

photomigrophraphs at 2000 magnification. In terms of diameters and numbers of open

dentinal tubules per 100 µm2, both treatment modalities presented significant

occlusion. The mean values of the diameters and the number of open dentinal tubules

per 100 µm2 were observed in Group I, Group II, and Group III, in decreasing order.

Significant differences were found among the groups in favor of the topical gaseous

ozone applied group and concluded that the dentine tubules in both treatment groups

were occluded, however more marked occlusion were seen in ozone treated group.

An in vitro study was conducted by Wan Hong Lan et al, to evaluate the

combined occluding effect of sodium fluoride varnish and Nd:YAG laser irradiadition

on human dentinal tubules. Thirty-six dentin specimens with exposed dentinal tubules


[Type text] Page 9

orifices were used in this study.The samples were randomly divided into four groups.

Group A, B and C were varnished by sodium fluoride,where as group D serves as

control.Then group C was lased by Nd:YAG laser by light painting. Three hours

later,group B and C were brushed by an electrical toothbrush for 30 min. Under SEM

observation,the control group shows numerous exposed dentinal tubule orifices and

the sodium fluoride varnished specimens showed closure of exposed dentinal tubule

orifices. After electrical tooth brushing, most of the sodium fluoride varnished was

brushed away, except in the specimen that were irradiated by Nd:YAG laser. Over

90% of the dentinal tubule orifices were occluded by sodium fluoride varnished

combined with Nd:YAG laser irradiation.

An in vivo study was conducted by Schwarz F et al, to evaluate and compare

the desensitizing effects of an Er:YAG laser and Dentin ProtectorA on cervically

exposed hypersensitive dentine. A group of 30 patients showing a total of 104

contralateral pairs of hypersensitive and caries-free teeth was selected and randomly

allocated in a split mouth design to either (1) Er:YAG laser or (2) the application of

Dentin Protector A where at one pair served as an untreated control in each patient.

The degree of sensitivity to a thermal stimulus was determined qualitatively with an

evaporative stimulus defined as a three second air blast at a distance of 2 mm from

each site to be tested. A qualitative registration of the degree of discomfort was

determined according to an arbitrary pain scale in 4 degrees. Recordings were

assessed before treatment, immediately after, 1 week, 2 and 6 months after treatment

by 1 blinded examiner. Both treatment forms resulted in significant improvements of

discomfort immediately after and 1 week post treatment. After 2 months, the

discomfort in the Dentin Protector A group increased up to 65% of the baseline score

and even up to 90% after 6 months, whereas the effect of the laser remained at the

same level that was achieved immediately after treatment. The differences

immediately after, 1 week, 2 and 6 months post treatment between both groups were

significant. Compared to the untreated control group, both treatment forms resulted in

a significant reduction of discomfort at each follow-up examination.

An in vivo study was conducted by Sebnem Dirikan Ipci et al, to evaluate and

compare the efficacy of Co2 and Er:YAG lasers alone and in combination with topical

sodium fluoride (NaF) in the management of dentine hypersensitivity. A group of 50


[Type text] Page 10

patients presenting with a total of 420 hypersensitive teeth were randomly allocated

into five groups. Group 1 was treated with 2% NaF, groups 2 and 3 were lased by a

Co2 or Er:YAG laser and groups 4 and 5 received NaF plus the Co2 and the Er:YAG

laser, respectively. The degree of thermal sensitivity was determined with an

evaporative stimulus consisting of a 1-sec air blast at a distance of 2 mm from each

site tested. Quantification of the degree of discomfort was determined according to a

four-point pain scale before treatment and 1 week, 1 months, and 6 months after

treatment. All treatment forms resulted in significant improvement of discomfort. At 1

week, 1 month, and 6 month, cold air blast scores were significantly reduced

compared to baseline scores, except for the NaF group. In the NaF group, there was a

statistically significant increase in mean degree of discomfort at 6 mo compared with

1 week and 1 month. Comparison of the other treatment regimens revealed that cold

air blast scores were significantly lower for the other four treatments than for NaF gel

alone. No superiority was found for desensitization among the Co2, Er:YAG, Co2,

NaF and Er:YAG,NaF groups and thus concluded that both the Co2 and Er:YAG

lasers have promising potential for the treatment of dentine hypersensitivity. Lasers in

combination with NaF gel appear to show better efficacy compared to either treatment

modality alone.

An in vivo study was conducted by Azher Banu Pathan et al, to evaluate the

effectiveness of three desensitizing agents on dentinal tubule obliteration and their

durability in use on the dentinal tubules. Sixty specimens were obtained from 30

extracted sound human maxillary first premolars. Each tooth was mesiodistally

sectioned to obtain 30 buccal and 30 lingual surfaces and enamel was removed in

order to simulate hypersensitive dentin. Specimens were divided into four groups with

15 specimens each. Group 1 samples were immersed in artificial saliva, Group 2

samples were coated with Vivasens, Group 3 samples were coated with VOCO

Admira Protect and Group 4 samples were coated with Neo Active Apatite

suspension. These specimens were examined under scanning electron microscope

(SEM) to find out the occluding ability of the respective products. The specimens

were brushed to find out their durability for 1 week and 1 month and were examined

under SEM. The results showed that Group 1 differed significantly from the Vivasens,

Admira, and Neo Active Apatite groups at 5% level of significance. The Vivasens


[Type text] Page 11

group differed significantly from the Admira and Neo Active Apatite group.The

Ormocer-based Admira Protect showed the best results.

An in vitro study was conducted by Samet Tosun et al, to evaluate the dentinal

tubule occlusion potential and penetration of Clinpro White Varnish (5% sodium

fluoride tricalcium phosphate) in the presence or absence of Nd: YAG laser. Seventy-

five dentin samples collected from 38 freshly extracted human molars were randomly

divided into five groups (n 15). Groups A, B, D and E were varnished with Clinpro,

whereas group C (no treatment) served as the control group. Groups B and E were

further irradiated with Nd:YAG laser. All study groups were subjected to pH cycling.

Groups A, B and C were evaluated for tubule occlusion using scanning electron

microscopy. Groups D and E were evaluated for penetration with confocal laser

scanning microscopy (SEM). Tubular occlusion of groups A and B were significantly

greater than group C. Tubular occlusion of group B were significantly greater than

group A. Penetration depth for group D was significantly greater than group E. Laser

application improved the tubular occlusion capacity of Clinpro,on the contrary, laser

reduced the penetration of Clinpro.

An in vivo study was conducted by Ozlem K et al,to determine and compare

the efficiency of the glutaraldehyde-containing agent (GCA), Nd:YAG, Er,Cr:YSGG

lasers and the combination of them on the dentin hypersensitivity (DH) treatment.

This study was performed with the participation of 17 healthy adult patients having

100 teeth with DH; the patients were randomly divided into five groups according to

the treatment protocol: (1) application of GCA on sensitive teeth, (2) Nd:YAG laser

irradiation on sensitive teeth, (3) application of GCA on sensitive teeth and then

Nd:YAG laser irradiation, (4) Er,Cr:YSGG laser irradiation on sensitive teeth, (5)

application of GCA on sensitive teeth and then Er,Cr:YSGG laser irradiation.

Sensitivity levels were assessed by the Yeaple probe on the buccal surfaces of the

teeth at a force setting of 10 g. Measurements were performed for 30 min, after 7, 90,

and 180 days of the therapy to assess the effects of desensitization. After sessions, DH

was significantly reduced in all groups at each measurement point. The Er,Cr:YSGG

laser with or without GCA application were the most effective ones in DH treatment.

Comparison of the treatment regimens demonstrated that the scores achieved with the

Yeaple probe were not significantly higher for the Nd:YAG laser groups than the


[Type text] Page 12

GCA alone group.This clinical study shows that the Er,Cr:YSGG laser have

promising potential for the treatment of DH.

An in vivo study was conducted by Sevda Kurt et al, to evaluate and compare

the efficacy of Er:YAG laser, Nd:YAG laser, PrevDent nano-hydroxyapatite

toothpaste plus Repairing Serum Kit (PNH), and NUPRO Sensodyne Prophylaxis

Paste with NovaMin (NPP) on dentin permeability reduction. Forty dentin discs

obtained from bovine incisors were divided into four study groups: Er:YAG laser-

treated Nd:YAG laser-treated PNH-treated and NPP-treated groups. The quantitative

changes in permeability of each dentin disc were measured using a computerized fluid

filtration method (CFFM) before and after desensitizer treatments. The dentin

surfaces and tubules were also morphologically detected by scanning electron

microscopy (SEM). In all groups, dentin permeability was significantly reduced after

the desensitizer and laser treatments. Among the groups, significant difference was

observed in only when comparing the Er:YAG laser and NPP-treated groups. SEM

analysis revealed physical changes in the dentin surface in all groups. All tested

desensitizers and laser treatments exhibited reduced dentin permeability. Also, surface

changes, such as complete or partial occlusion or shrinkage of dentin tubules, were

observed in all groups. Although the laser groups performed best, the PNH protocol

can be considered as an alternative therapeutic product.

An in vivo study was conducted by Romeo Umberto et al, to compared the

effectiveness of GaAlAs diode laser alone and with topical sodium fluoride gel (NaF).

The study was conducted on 10 patients and 115 teeth with dentinal hypersensitivity

assessed by air and tactile stimuli measured by Numeric Rating Scale (NRS). Teeth

were randomly divided into G1 treated by 1.25% NaF; G2 lased with diode laser

fluence G3 received NaF gel plus laser G2. NRS was checked at each control.

Significant pain reduction was showed.The NRS reduction percentages were

calculated, and there was a concrete decrease of DH above all in G3 than G2 and G1

and thus concluded that diode laser is a useful device for DH treatment if used alone

and mainly if used with NaF gel.

An in vivo study was conducted by Sandra Ribeiro Cunha et al, to evaluate the

association between Nd:YAG laser and two desensitizing dentifrices containing 15%


[Type text] Page 13

NovaMin or 8% arginine, as potential treatments for dentin hypersensitivity (DH).

DH was simulated by EDTA application for 2 min. Specimens were then analyzed

with an environmental scanning electron microscope (ESEM) to ensure open dentin

tubules (ODT), counted by using ImageJ software. Specimens were randomized into

eight groups (n = 10): Laser (L), Laser+ Photoabsorber (LP), Arginine (A),

Arginine+Laser (AL), Arginine+Laser+Photoabsorber (ALP), NovaMin (N),

NovaMin+Laser (NL), and NovaMin+Laser+Photoabsorber (NLP). Laser irradiation

was performed with 1 W, 4 irradiations of 10 second each, with 10 second intervals

between them. After treatment, specimens were again analyzed by ESEM and

submitted to erosive/abrasive cycling for 5 days. A final ESEM analysis was

performed. None of the associations tested presented better tubule occlusion than

NovaMin by itself. Arginine was the only treatment that presented improved tubule

occlusion when associated with Nd:YAG laser.

An in vivo study was conducted by I.DURAN et al, to compare the long-term

effectiveness of five desensitizing products on 25 male and 27 female patients (total

52) aged 21–67 years (mean 36 ± 7 years) suffering from cervical dentine sensitivity.

All subjects were seen by the same examiner (ID) who was blinded to the applied

treatment for 3-month clinical study. Patients were asked to record their overall

sensitivity by marking a point on a 10 cm Visual Analogue Scale (VAS). 277

sensitive teeth were treated by one of the five desensitizing products, of A paired

(split mouth) study design was used and selection of quadrants was randomized. At

the post-treatment and at 10 days and 3 months periods, sensitivity measurements

were recorded by the same investigator (ID). Statistical analysis showed that all of the

VAS scores at post-treatment evaluation points were significantly decreased

compared with baseline data. There was a significant reduction in mean sensitivity

scores in the Protect Liner F and the Health-Dent Desensitizer groups when compared

with Fluoline varnish at the 10-day time point. At 3 months, the Protect Liner F group

continued to show a significantly reduced sensitivity level when compared with

Health-Dent Desensitizer, Single Bond, Fluoline and Gluma Desensitizer. The present

study demonstrated that although at the end of 3-month evaluation period all

desensitizers showed lower VAS sensitivity values compared with baseline, there

were differences in the level of reduction of cervical dentine sensitivity.


[Type text] Page 14

An in vitro study was conducted by Eleftherios Terry R. Farmakis et al, to

evaluated the efficacy of bioglass and Nd:YAG laser irradiation on dentinal tubuli

orifice occlusion (DOO) by comparing samples examined under environmental

scanning electron microscope (ESEM) after applying each desensitizing approach

separately and in combination. Forty-eight human molars were collected, randomly

organized in 4 equal groups and had their cervical dentin exposed. Additionally, in

half of the specimens of each experimental group, the smear layer was removed

(subgroups A1, B1, C1, and D1). Group A received NovaMin paste treatment for 5

minutes (NM) to the experimental surface. Group B received Nd:YAG laser

irradiation. Group C received NM followed by laser. Group D was treated with laser

followed by NM. All specimens were stored for 24 hours and evaluated for DOO

under ESEM by 4 blinded observers.The presence of a smear layer significantly

contributed to DOO regardless of the treatment modality. Compared with group A, all

other treatments delivered significantly more occluded dentin orifices. A layer

formation was observed in subgroups C2 and D2. Under these experimental

conditions, a smear layer was essential for successful DOO. Laser irradiation alone

and combined with NovaMin proved superior to NovaMin alone on DOO. This

combined approach has the potential to improve the outcome of treatment for cervical

dentin hypersensitivity. The biological significance of this newly formed layer needs

to be elucidated.

An in vivo study was conducted by Felice Femiano et al. This study compares

sensitivity reduction after dental restoration with and without prior diode laser (DL)

irradiation for cervical dentine hypersensitivity (CDH) from non-carious cervical

lesions (NCCLs) unresponsive to desensitizing agents. Eighty-eight teeth of 28

subjects, with CDH from NCCL were included in this study. NCCLs of each oral

quadrant were randomized in two groups (study group (SG)) to estimate the

sensitivity reduction after dental restoration (SG-1) compared with the DL irradiation

used prior to restoration placement (SG-2). The subjects were asked to rate the

sensitivity experienced during air stimulation using a visual analog scale before

(baseline), immediately after and at 6 and 12 months from restoration. The outcomes

showed a significant reduction of discomfort compared to baseline for NCCLs of SG-

2 with the decrease of 78.5, 78.9 and 78.1 % immediately and at 6 and 12 months

after restoration, respectively; in comparison with the decrease of 70.1, 67, and 65.3


[Type text] Page 15

% for NCCLs of SG-1 immediately and at 6 and 12 months after restoration,

respectively; and compared to baseline. The DL irradiation prior to dental restoration

can further improve the painful symptomatology of CDH from NCCL unresponsive to

desensitizing agents.

An in vitro study was conducted by Po-Jen Hsu et al, to evaluate the combined

occluding effects of fluoride-containing dentin desensitizer and neodymium:yttrium

aluminum garnet (Nd-YAG) laser irradiation on human dentinal tubules. All six of the

groups of dentin samples (A–F) included in this study received applications of

fluoride-containing dentin desensitizer Groups A and B served as controls, Groups C

and D were treated with 0.5 M vitamin C solution, whereas groups E and F underwent

brushing with an electric toothbrush, Groups B, D, and F received Nd-YAG laser

irradiation, to allow observations of the occluding effects on the dentinal tubules

before and after Nd-YAG laser irradiation. Scanning electron microscopy (SEM)

revealed that the fluoridated dentinal tubule-occluding agent (FDTOA) formed a fine

crystalline deposit on the dentin surface. After soaking in 0.5 M vitamin C solution

for three hours, the crystalline deposit of the FDTOA was completely dissolved.

Furthermore, brushing of the teeth 3,600 times removed most of the occluding agent.

When the application of FDTOA was combined with Nd-YAG laser irradiation, the

dentin melted and then recrystallized. The occluding agent was thus ‘burned into’ the

dentinal tubules, and could neither be dissolved by vitamin C solution nor removed by

brushing. concluded that the FDTOA combined with Nd-YAG laser irradiation burns

the occluding agent into the dentinal tubules, thereby resisting the effects of an acidic

diet and brushing and increasing the duration of the desensitizing effect.

An in vitro study was conducted by T. Pamir et al, to evaluate the efficacy of

three desensitizing agents vs. placebo. One hundred and six hypersensitive teeth of 26

patients were included in this study, and the baseline hypersensitivity level of all teeth

was established as ‘moderate’ by using Visual Analogue Scale (VAS). The teeth were

divided into four groups: to the first group 5% potassium nitrate bio-adhesive gel, to

the second 2% sodium fluoride bio-adhesive gel and to the third one step adhesive

system Prompt L-Pop were applied as desensitizing agents. Group 4 was the control

group in which a desensitizer-free bio-adhesive gel was used as placebo. Post

treatment and eighth week control measurements were recorded on VAS. It was


[Type text] Page 16

observed that the efficacy of three desensitizing agents did not differ from each other

and except for placebo all reduced moderate dentin hypersensitivity effectively. 5%

potassium nitrate, 2% sodium fluoride bio-adhesive gels and one step bonding agent

Prompt L-Pop were effective in reducing moderate dentine hypersensitivity.

An in vitro study was conducted by S. A. M. Corona et al, to evaluate in vivo

the use of low-level galium–aluminium– arsenide (GaAlAs) (BDP 600) laser and

sodium fluoride varnish (Duraphat) in the treatment of cervical dentine

hypersensitivity. Twelve patients, with at least two sensitive teeth were selected. A

total of 60 teeth were included in the trial. Prior to desensitizing treatment, dentine

hypersensitivity was assessed by a thermal stimulus and patients’ response to the

examination was considered to be a control. The GaAlAs laser was irradiated on

contact mode and fluoride varnish was applied at cervical region. The efficiency of

the treatments was assessed at three examination periods: immediately after first

application, 15 and 30 days after the first application. The degree of sensitivity was

determined following predefined criteria. Data was submitted to analysis and no

statistically significant difference was observed between fluoride varnish and laser.

Considering the treatments separately, there was no significant difference for the

fluoride varnish at the three examination periods and for laser therapy, significant

difference was found solely between the values obtained before the treatment and 30

days after the first application. It may be concluded that both treatments may be

effective in decreasing cervical dentinal hypersensitivity. Moreover, the low-level

GaAlAs laser showed improved results for treating teeth with higher degree of

sensitivity.

An in vitro study was conducted by N. Gautham Kumar et al, to evaluate

clinically and under scanning electron microscopy (SEM) the efficacy of Nd:YAG

laser irradiation alone and in combination with 5% sodium fluoride varnish in the

management of dentin hypersensitivity. The study was conducted on 40 patients

divided into four groups who had at least one tooth of Grade III mobility with

clinically elicitable dentin hypersensitivity. Following the pretreatment assessment of

hypersensitivity using the visual analog scale (VAS) and cold air blast test, the

selected tooth in all the groups received 1% citric acid treatment for 1 minute. Group

1 patients received no further treatment; group 2, 3, and 4 patients received additional


[Type text] Page 17

treatment with 5% sodium fluoride varnish, Nd:YAG laser for 2 minutes and a

combination of 5% sodium fluoride varnish and Nd:YAG laser, respectively. Two

hours following treatment, hypersensitivity was again assessed and the teeth were

extracted, sectioned and scanned using scanning electron microscopy (SEM) The

mean VAS score in group 1 showed a 27% increase from baseline, but groups 2, 3,

and 4 showed a decrease of 33%, 44% and 62%, respectively. The mean cold air blast

score showed a 22% increase in group 1, but values decreased by 43%, 50%, and 83%

in groups 2, 3, and 4, respectively. The number of patent tubules also progressively

decreased from group 1 through group 4. The combination of Nd:YAG laser and 5%

sodium fluoride varnish seems to show an impressive efficacy, when compared to

either treatment alone, in treating dentin hypersensitivity. The SEM findings seem to

relate to the clinical findings in that reduction in number/patency of tubules was

associated with improvement in treatment efficacy

An in vitro study was conducted by Anely Oliveira Lopes et al, to assess

different protocols for the treatment of dentin hypersensitivity with low-power laser

(with different doses), high-power laser and a desensitizing agent, for a period of 12

and 18 months. The lesions from 32 patients (117 lesions), were divided into nine

groups (n = 13): G1: Gluma Desensitizer, G2: low-power laser with low dose, G3:

low-power laser with high dose, G4: low-power laser with low dose + Gluma

Desensitizer, G5: low-power laser with high dose + Gluma Desensitizer, G6:

Nd:YAG laser, G7: Nd:YAG laser + Gluma Desensitizer, G8: low-power laser with

low dose + Nd:YAG laser, and G9: low-power laser with high dose + Nd:YAG laser.

The level of sensitivity of each volunteer was assessed by visual analog scale of pain

(VAS) with the aid of air from the triple syringe and exploration probe, 12 and 18

months after treatment. All analysis were performed separately for air and probe

stimulus, all treatments were effective in reducing dentinal hypersensitivity and the

results were considered not statistically different from those at 12 months and 18

months.

An in vitro study was conducted by Zahi badran et al, to obliterate the exposed

dentinal tubules by introduction of laser desensitization was introduced as an

alternative efficient tool for the immediate treatment of tooth hypersensitivity. Nine

freshly extracted single-rooted teeth were immersed for 30 min in a sodium


[Type text] Page 18

hypochlorite solution (NaOCl 3%). The teeth were then thoroughly brushed until

organic debris had been completely eliminated. The specimens were then left for 24 h

in saline buffer. On each buccal side of the root of the included teeth, two deep

dentinal cavities were prepared using a diamond bur mounted on a high-speed

handpiece. The teeth were then embedded in putty in small petri dishes. All cavities

were then acid-etched with 37% phosphoric acid. After 20 s, the phosphoric acid was

removed by rinsing with saline buffer for 40 s. Immediately after rinsing, an Er:YAG

laser device was used to irradiate one test cavity in each tooth for 30, 60 and 120 s.

They were then viewed with a scanning electron microscope at 20 kV under high-

vacuum conditions. None of the irradiated samples showed signs of thermal damage

(cracking, melting or carbonization) to the irradiated dentin.

An in vivo study was conducted by Anisha Merh et al, to evaluate the

immediate efficacy of diode laser versus desensitizing paste containing 8% arginine

and calcium carbonate in the treatment of dentine hypersensitivity. Fifty patients with

complain of tooth hypersensitivity were randomly selected for an 8 week clinical trial

with the set inclusion and exclusion criteria. Each patient was assigned to one of the

two study groups: Group 1 (n=25) - 8% arginine and calcium carbonate paste and

Group 2 (n=25) - Diode laser, who received a baseline evaluation of tactile

hypersensitivity with the help of dental explorer and an air blast hypersensitivity. The

effectiveness of the therapy was assessed by VAS Scale of 10, along with the hard

and soft tissue evaluation, at 4 examination periods: 1) immediately after the

application of the diode laser 2) after 15 days 3) after 4 weeks & 4) after 8 weeks. 8%

arginine and calcium carbonate showed significant results (67.27%) than diode laser

(56.55%) at immediate and 4 weeks evaluation by mechanical stimulus and

immediate evaluation by air stimulus. Diode laser showed highly significant results in

progressive decrease in the dentin hypersensitivity till 8 weeks whereas 8% arginine

showed highly significant results till 4 weeks. The immediate efficacy of 8% arginine

and caco3 was higher as compared to diode laser. Diode laser showed progressive

reduction till 8 weeks whereas showed progressive reduction only till 4 weeks.

An in vivo study was conducted by Harshul Sharma et al, to evaluate

the efficacy of MI varnish and Clinpro XT varnish in reducing dentinal

hypersensitivity. Patients with cervical dentinal hypersensitivity were selected for the


[Type text] Page 19

study. The teeth to be tested were isolated. Then, a blast of air and ice cold water was

applied on the tooth surface and the score was measured by visual analog scale. The

patients were randomly assigned to one of the treatment groups (Group 1: MI varnish;

Group 2; Clinpro XT varnish). The sensitivity scores were recorded immediately and

after 1 week of therapy. Although both varnishes were shown to reduce the dentinal

hypersensitivity in patients, MI Varnish was a better agent to reduce dentinal

hypersensitivity than Clinpro XT varnish.

An in vivo study was conducted by Marilia De Lima Soares et al, to compare

the efficacy of neodymium-doped yttrium-aluminum garnet (Nd:YAG) laser, gallium-

aluminum-arsenide (GaAlAs) laser and 2% neutral fluoride gel in the treatment of

dentinal hypersensitivity. Twenty-three patients were evaluated, involving a total of

48 quadrants with at least 1 tooth with dentinal hypersensitivity. Pain intensity was

recorded on a visual analog scale at the time of clinical examination (baseline),

immediately after treatment, and 1 week post treatment. Teeth were treated with 60

seconds of 2% neutral fluoride gel application or 60 seconds of laser treatment

Nd:YAG laser at a distance of 0.5 cm or GaAlAs laser in contact as well as sham

treatments so that patients remained blind to their treatment group. All treatments

provided adequate pain reduction immediately post treatment, but laser treatments

resulted in significantly greater reductions in pain intensity.

An in vitro study was conducted by Sneha Anil Rajguru et al, to compare the

effects of two desensitizing dentifrices containing NovaMin and arginine on dentinal

tubule occlusion with and without citric acid challenge in vitro using confocal laser

scanning microscopy (CLSM).Forty dentin discs were randomly divided into Groups

I and II containing twenty specimens each, treated with NovaMin and arginine

containing dentifrices, respectively. Groups I and II were divided into subgroups A

and B where IA and IIA underwent CLSM analysis to determine the percentage of

tubule occlusion while IB and IIB underwent 0.3% citric acid challenge and CLSM

analysis. A novel grading system was devised to categorize tubule occlusion. In

Group II, the percentage of occluded tubules was highest for IIA and least for IIB

having statistical significance. In Group I, the difference between IA and IB was

statistically insignificant. On the comparison between IB and IIB statistically

indifferent result was obtained, whereas the difference between IA and IIA was


[Type text] Page 20

statistically significant.The results of grading system were for IA 50% of samples

belonged to Grade 2, for IIA 60% Grade 3, and for IB 70% and for IIB 90% Grade 2.

Dentinal tubule occlusion with arginine containing dentifrice was significantly higher

than NovaMin. However, it could not resist citric acid challenge as effectively as

NovaMin. The effects of NovaMin were more sustainable as compared to arginine

containing dentifrice, thus proving to be a better desensitizing agent.

An in vitro study was conducted by Sian Bodfel Jones et al, to evaluate the

ability of a dentifrice containing the bioactive material calcium sodium

phosphosilicate (CSPS) to remineralise the surface of dentine and physically occlude

patent tubules in a 20 day in situ randomised clinical study. Changes in surface

microhardness and surface topography of dentine specimens treated for 5, 10, 15 and

20 days, twice daily with either a dentifrice containing 5% CSPS or a fluoride-only

containing placebo dentifrice were compared. The substantivity of any mineral

deposits formed on the surface of dentine were investigated by the application of an

intra-oral dietary acid challenge twice daily during the final 10 days of treatment.

After 5 and 10 days of treatment, the dentine samples in both treatment groups

demonstrated an increase in surface microhardness. After 10 days of treatment the

increase in surface hardness was directionally greater for the specimens treated with

5% CSPS dentifrice. Introducing an intra-oral acid exposure resulted in a reduction in

surface micro-hardness which was significantly greater for the specimens treated with

the placebo dentifrice compared to the dentifrice containing 5% CSPS, at day 20.

Occlusion of the patent tubules was evident at each time-point and was significantly

greater for the 5% CSPS containing dentifrice on days 5 and 10. On day 15 both

dentifrices demonstrated the same degree of occlusion. This in situ study

demonstrated that dentifrice containing 5% CSPS may have potential to mineralise

and occlude the dentine in the oral environment.

An in vitro study was conducted by Ryan C. Olley et al, to investigate the

dentine occlusion and acid resistance of dentifrices developed to treat dentine

hypersensitivity. This was a single centre, single blind, randomised, split mouth, four

treatments, two period crossover, in situ study in healthy subjects. Subjects wore

buccal intra-oral appliances each fitted with four dentine samples over four

consecutive days with one study product applied per appliance; 8% strontium acetate


[Type text] Page 21

in silica base, 1040 ppm sodium fluoride (Sensodyne1 Rapid Relief), 8% arginine,

calcium carbonate, 1450 ppm sodium monofluorophosphate (Colgate Sensitive Pro-

Relief1), 1450 ppm sodium fluoride (control paste) and water. On days 3 and 4, two

agitated grapefruit juice challenges (ex vivo) occurred for 1 min. At the end of each

treatment day 1 dentine sample was removed from each appliance for scanning

electron microscopy (SEM). The extent of tubule occlusion was measured using an

examiner-based visual scoring index. In total, 28 subjects completed the study. On

day 2, both test dentifrices demonstrated significantly better dentine tubule occlusion

than water and control paste (8% strontium and 8%). After 3 and 4 days of twice

daily brushing with acid challenges on days 3 and 4 the strontium-based dentifrice

demonstrated significantly better dentine occlusion than all other treatments

Strontium acetate and arginine-based dentifrice result in statistically significant

dentine tubular occlusion compared to controls, but the arginine-based dentifrice is

more susceptible to acid challenge.

An in vitro study was conducted by Karl Anton Hiller et al, to evaluate the

effect of toothpastes with different active ingredients on dentin permeability using an

extended protocol including multiple applications and several thermal ageing cycles

in the presence or absence of human saliva. The Null hypothesis was that dentin

permeability of a hydroxyapatite containing toothpaste (BR), a potassium nitrate (SP)

and an arginine and calcium carbonate (EH) containing toothpaste were similar.

Dentin permeability was measured as hydraulic conductance using a commercially

available capillary flow system (Flodec, Geneva) and results were expressed as %

relative to matching controls. Without saliva, the ranking (best first) of dentin

permeability was BR(61%) < SP(87%) < EH(118%), with saliva EH(63%) <

SP(72%) < BR(88%). Saliva increased or decreased permeability dependent upon the

test material. BR reduced dentin permeability significantly more in absence of saliva,

with saliva EH was superior to BR. Repeated material application decreased and

thermal ageing increased dentin permeability. The different tooth pastes reduced

permeability differently, the best being BR without saliva, the least EH without saliva.

The newly introduced test conditions (ageing, saliva, multiple applications)

influenced single results significantly.

Material And Methods

[Type text] Page 22

MATERIALS AND METHODS:

SOURCE OF DATA:

Forty five extracted maxillary premolar teeth were collected from the

Department of Oral and Maxillofacial Surgery, P.M.N.M Dental College and

Hospital, Bagalkot.

MATERIALS USED IN THE STUDY:

• Distilled water with thymol

• Artificial Saliva

• Scaler

• Low speed hand piece

• Low speed Diamond saw

• High speed round diamond bur

• 1% citric acid

• Rhodamine B isothiocyanate dye

• Sodium fluoride varnish

• Er:YAG laser

• Scanning Electron Microscope (SEM)


[Type text] Page 23

• Confocal Laser Scanning Microscopy (CLSM)

METHODS OF COLLECTION OF DATA

Freshly extracted maxillary premolar teeth were collected and stored in 4oC

distilled water with thymol until further processing.

INCLUSION CRITERIA:

• Maxillary first premolar teeth.

• Teeth with completely formed apices.

• Non carious teeth.

EXCLUSION CRITERIA:

• Carious teeth.

• Fractured teeth.

• Restored teeth.

METHODOLOGY:

Forty five intact human premolars stored in distilled water (4°C) mixed with

thymol was used in this study. Prior to their preparation, soft tissue and debris was

removed using a scaler and a low-speed handpiece with non-fluoride pumice powder.

A 3-mm-thick horizontal slice was prepared from the cemento-enamel junction of

each tooth using a slow-speed diamond saw. Each slice was transversely separated

into two halves as buccal and lingual. To expose the dentinal tubule orifices, the

cementum layer from each slice was removed with a high-speed bur. Smear layers on

the dentinal tubule orifices will be removed by 1% citric acid for 5 min and then

samples was washed with distilled water. By this way 90 samples was obtained and

these samples was randomly divided into six equal groups. Groups A, B, C and D was

used for the evaluation of tubule occlusion with SEM.

Groups B, D, E and Group F were applied with sodium fluoride varnish and

Group C, D and Group F was irradiated using a Er:YAG laser Group A was untreated


[Type text] Page 24

and served as control group. Groups E and F was separated for dentin permeability

with CLSM

Er:YAG Laser Irradiation:

For groups C, D and F, following sodium fluoride varnish application, the

dentine specimens was irradiated with an Er:YAG laser with a straight quartz round

tip of 600 µm diameter at an energy level of 60 mJ/pulse and a repetition rate of 30

Hz, without water irrigation.The laser beam was swept in a mesio-distal fashion for

10 sec with the beam directed perpendicularly to the dentine surface in non-contact

mode at a distance of 3–4 mm.

Dentin Analysis Via Confocal laser Scanning Microscopy:

Topical sodium fluoride applied to the samples of groups E and F was labelled

with rhodamine B isothiocyanate dye (0.1% by weight) to determine the effect of

different methods over the penetration depth of the potassium fluoride varnish. CLSM

was used in fluorescent mode to obtain images. A Helium-neon laser was used as the

light source.

Dentin Analysis Via Scanning Electron Microscopy:

The potential of sodium fluoride to occlude dentin tubules totally or partially was

evaluated as the samples of groups A, B, C and D was washed with deionised water

and gently dried with air by using a three-in-one syringe. The samples was coated

with a thin layer of gold (20–30 nm) under vacuum in an ion-sputtering device in

order to increase conductivity. Following SEM images was recorded. Image analysis

were performed at 2000x to determine the diameter of the open tubules.

STATISTICAL ANALYSIS:

The scores thus obtained were tabulated and statistically analyzed by

Kolmogorov Smirnov test, Analysis of variance (ANOVA) followed by Tukeys

posthoc procedures and independent tests were applied.

Sample size estimation

Page | 26

Sample size

Standard deviation in the 1st group S1 =.20

Standard deviation in the 2nd

group S2 =.25

Mean difference between 1st and 2

nd sample =0.2974=d

Effect Size =1.32177777777778

Alpha Error (%) = 5

Power (%) = 95

Sided = 2

Number needed (n)= 15 in each group should be taken

Formula

212/12

2βα

2

z+zd

)(S=n

Where, Z1-α/2= Z-value for α level= 1.96

Z1-β= Z-value for β level= 1.682

Results

Page | 27

Table 1: Normality of tubules diameter of dentinal tubules scores by Kolmogorov

Smirnov test

Groups Z-value p-value

Tubules diameter scores

Group A 0.7360 0.6510

Group B 1.1690 0.2424

Group C 0.6400 0.8070

Group D 0.5230 0.9480

Table 2: Normality of depth of penetration of die in dentinal tubules scores by

Kolmogorov Smirnov test.

Depth of penetration of die in dentinal tubules

Group E 0.3890 0.9980

Group F 0.5250 0.9460

Table 3: Summary of tubules diameter scores in four study groups (A, B, C and D)

Groups N Min Max Mean SD SE

Group A 15 4.25 5.21 4.73 0.20 0.05

Group B 15 3.55 4.60 3.75 0.25 0.06

Group C 15 2.40 2.86 2.60 0.13 0.03

Group D 15 1.35 2.05 1.71 0.16 0.04

Table 4: Comparison of four study groups (A, B, C and D) with respect to mean

tubules diameter scores by one way ANOVA

Sources of

variation

Degrees of

freedom

Sum of

squares

Mean sum

of squares

F-value p-value

Between groups 1 1628.03 1628.03 107.3176 0.0001*

Within groups 28 424.77 15.17

Total 29 2052.80

*p<0.05

Results

Page | 28

Table 5: Pair wise comparisons of four study groups (A, B, C and D) with respect to

mean tubules diameter scores by Tukeys multiple posthoc procedures

Groups Group A Group B Group C Group D

Mean 4.73 3.75 2.60 1.71

SD 0.20 0.25 0.13 0.16

Group A -

Group B P=0.0002* -

Group C P=0.0001* P=0.0002* -

Group D P=0.0001* P=0.0001* P=0.0001* -

*p<0.05

Note: * indicates difference between two groups found to be statistically significant

Table 6: Comparison of two study groups (E and F) with respect to mean depth of

penetration of die in dentinal tubules scores by independent t test

Groups n Mean SD SE t-value P-value

Group E 15 35.07 3.52 0.91 10.3594 0.0001*

Group F 15 20.33 4.24 1.09

*p<0.05

Results

Page | 29

Graph 1: Comparison of four study groups (A,B,C and D) with respect to mean of

tubules diameter of dentinal tubules scores.

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

4.00

4.50

5.00

Group A Group B Group C Group D

4.73

3.75

2.60

1.71

0.20 0.25 0.13 0.16

Mea

n v

alue

Mean SD

Results

Page | 30

Graph 2: Comparison of two study groups (E and F) with respect to mean depth of

penetration of die in dentinal tubules scores

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

Group E Group F

35.07

20.33

3.52 4.24

Mea

n v

alue

Mean SD

Discussion

Page | 31

DISCUSSION

In current study, the efficacy of a sodium fluoride desensitizing varnish in

combination with Er:YAG laser irradiation for treatment of dentin tubule occlusion

was assessed. Citric acid has been reported to be the preferred agent to expose

dentinal tubule orifices. Thus, soaking in freshly prepared dentin discs in 1% citric

acid for 5 min was used to eliminate the remnants of the naturally-occurring smear

layer with no harmful effects on the surface structure. Topical application of sodium

fluoride exerts a beneficial desensitizing effect on exposed dentine and cementum.1

Sodium fluoride, relies on interactions occurring between sodium fluoride

(NaF) and calcium ions in dentinal fluid. At the end of this reaction, calcium fluoride

crystals (CaF2) form that are deposited on the dentinal tubules, mechanically

occluding the opening. However, as these crystals are small in diameter (about

0.05mm), the application of NaF solution alone may not be effective in narrowing the

diameter of dentinal tubules of hypersensitive teeth and may require repeated

applications. To overcome this limitation, the use of NaF in different forms (i.e

varnish, gel), combination of sodium fluoride with other chemicals such as tricalcium

phosphate, resin and application of sodium fluoride with laser systems may be

proposed.4

The laser parameters having an effect on the amount of energy applied to a

given surface include power level (W), exposure time (seconds), energy density

(J/cm2), distance from the surface and the angle between the target tissue and the tip.

When the Er:YAG laser power level is more than 1.5 W/cm2, it is likely that the

dentin cracks and fissures and the dentin’s protein structure alter, causing damage to

the pulp.5

Er:YAG lasers are effectual in both medical and dental applications because of

having a thermomechanical ablation mechanism and because of the high absorption of

their wavelength by water reductions in dentinal hypersensitivity have been reported

with the use of the Er:YAG laser, due to its action of evaporating the water, in the

dentine, which leads to degranulation or coagulation of the organic elements, causing

their accumulation and blockage of dentinal tubules which is most essential for

reduction of dentinal hypersensitivity.8

Recently, application of various lasers, including He-Ne, CO2, Nd:YAG,

Er:YAG and 810-nm diode lasers have been presented as a potential alternative

Discussion

Page | 32

strategy for the treatment of dentinal hypersensitivity. These lasers can result in either

an occluding effect on dentinal tubules or a desensitization effect by reducing the

pulpal nerve’s pain threshold. The occluding effects of these lasers have rarely been

compared. On the other hand, there have been some reports about the biological

effects of low level lasers in decreasing tooth sensitivity. Since the mechanism of low

level lasers is different from that of high level lasers, the comparison of these two

types of effects could be the subject of a new study.8

Since there are many different and often contradictory reports about the

occluding effects of different lasers, the study was mainly aimed at comparing the

effects of Er;Cr:YSGG, Nd:YAG, CO2 and 810-nm diode lasers by scanning electron

microscopy (SEM). Although occluding effects are not the only effect of lasers that

decrease sensitivity, and recently, effects of lasers on nerve ends have also been

considered important, occluding effects are still considered to be the most effective

method for decreasing tooth sensitivity. Therefore, laser therapy should be attempted

in human studies and if successful, then as a part of patients treatment plans as well.11

The laser therapy had no adverse effect on the pulp. In this long term clinical

study, both Nd:YAG and Er,Cr:YSGG lasers and sodium fluoride desensitizer

resulted in a decrease in dentinal hypersensitivity with no adverse effects on tooth

vitality but, factors which influence the treatment of dentinal hypersensitivity are the

the clinical equipment, economy, patient cooperation, time efficiency of application

and clinician’s proficiency with the technique may affect the treatment measures be

used for for treating dentinal hypersensitivity. Randomized and controlled clinical

studies are necessary for finding the most suitable treatment modality.11

The application of desensitizing agents to those dentinal tubules exposed to

the oral environment constitutes the basis of traditional dentinal hypersensitivity

treatment. Desensitizing agents try to constrain painful stimuli either by means of

covering the dentinal tubules with coating mechanisms or by means of adjusting

tubule contents via protein precipitation, coagulation, or the creation of insoluble

calcium complexes. Owing to the fact that the application of tubule sealing agents

brings some drawbacks, such as the need for repetitive applications, extended

duration of treatment and patient compliance, the usage of alternative treatment

modalities has become necessary. The formulation of glutaraldehyde-containing agent

(GCA) consists of fluoride, hydroxyethyl methacrylate (HEMA), glutaraldehyde and

benzalkonium chloride. The glutaraldehyde reacts with the albumin in dentinal fluid

Discussion

Page | 33

that leads to the precipitation of this protein. In the literature, it is claimed that HEMA

polymerization takes place, which leads to the formation of deep tags so that the

dentinal tubules are completely occluded12

Nakabayashi and Honda developed a reactive copolymer consisting of

polymethyl methacrylate and polystyrene sulphonoic acid which bonded to the smear

layer covered dentine. In a longitudinal study, the ability of this resin system to

occlude was evaluated on the different dentine specimens. Presumably, the tubule

occlusion produced by the pain-free resin desensitizer would last long enough (i.e. 1–

2 months) to permit natural physico-chemical reactions to occlude the tubules and

maintain the desensitization.15

The fluoridated dentinal tubule-occluding agent used in treating dentin

hypersensitivity results in immediate relief from dentin hypersensitivity. However, the

agent used to block the dentinal tubules was incapable of binding to the walls of

dentinal tubules and thus was kept in place only by mechanical means; therefore, the

agent could be dissolved by vitamin C solution or worn away by the action of an

electric toothbrush and may eventually become ineffective. Thus the stability of the

fluoridated dentinal tubule-occluding agent is not definitive and its long-term

effectiveness may decrease with time, therefore combination of laser with fluoridated

varnish is used in the current study.18

Gelskey et al used an Nd-YAG laser combined with a He-Ne laser to reduce

dentin hypersensitivity to air by 58% and hypersensitivity to mechanical stimulation

by 61%. Lan and Liu used an Nd-YAG laser to reduce dentin hypersensitivity to air

by 65% and hypersensitivity to mechanical stimulation by 72%. Unfortunately, the

cure rate for treating dentin hypersensitivity using Nd:YAG laser is not very

satisfactory. So in the current study Er:YAG laser is being selected to reduce the

dentinal hypersensitivity. Although low-level lasers and fluoride varnishes present

distinct modes of action, both treatments provided a significant overall relief in

dentine hypersensitivity (particularly for the sharpest pains) and showed similar

performance.19

The desensitizing agents provide a significant relief in sharp painful

symptomatology and can be reapplied, in case of recurrent discomfort, as they consist

of non-invasive methods. Nevertheless, the ideal treatment technique, one which

should not irritate the pulp, nor cause pain, should be easy and practical to perform,

effective for a long period, as well as accessible to the great majority of population, is

Discussion

Page | 34

still to be developed. There is a need for a more systematic approach to the clinical

management of cervical dentine hypersensitivity, particularly in determining the long-

tem effect of the currently available desensitizing agents. For more effective

treatment, further investigation is required to increase the understanding of the

mechanisms and aetiology of dentinal pain. The findings revealed by both laboratory

and clinical research are extremely important to support the development or

improvement of therapies that may acutely contribute to the treatment of dentinal

hypersensitivity sufferers.20

Er:YAG laser is considered as a gold standard for the treatment of dentinal

hypersensitivity because it has been shown to have the capacity to obliterate the

dentinal tubules, by melting and resolidifying dentin, without pulp injuries or cracks

in irradiated dentin, when used with an adequate protocol. Moreover, a depth of

sealing of 4 μm within the dentinal tubules has been shown, so that there was

immediate improvement of dentinal hypersensitivity. However, little is known about

its in vivo effects in the long term and associations with other treatments. The

Er:YAG laser had an additional analgesic effect when compared with the other high-

power lasers. This probably occurred because the irradiation might have temporarily

altered the final part of the sensory axons and blocked both the C and Aβ fibers,

preventing the patient from feeling pain.22

Low intensity laser irradiation is capable of occluding exposed dentinal

tubules. The occluding effect is proportional to the duration of irradiation when using

the same energy and frequency settings. sixty second of irradiation seemed sufficient

for almost total occlusion of in the irradiated spot. With this duration, heat damage to

the pulp is unlikely to occur with the energy settings used. The main advantage of

Laser is the immediate effect after a single treatment session. Several studies have

shown that Laser can be maintained over time A clinical study compared Er:YAG

Laser to the topical application of 5% sodium fluoride paste which resulted in

effective for the occlusion and narrowing of dentinal tubules for the

treatment of dentinal hypersensitivity.23

According to Landry and Voyer, there is no ideal desensitizing agent and any

treatment for dentin hypersensitivity should be effective by only one application and

should satisfy the following parameters proposed by Grossman (1934): not irritating

pulp, not causing pain, easy application, long-lasting effect, not discoloring or

staining teeth, not irritating soft tissues or periodontal ligament, low-cost.24

Discussion

Page | 35

Er:YAG and Nd:YAG lasers are thought to be able to treat dentin

hypersensitivity by occlusion or narrowing of the dentinal tubules. The Nd:YAG laser

helps to obtain a non-porous structure by melting the surface; Nd:YAG laser

treatment also has an additional analgesic effect by blocking nerve conduction.

Various clinical and laboratory studies have proven the superiority of various laser

types; studies have shown that Er:YAG and Nd:YAG lasers provide similar results

and that two lasers can be used successfully in the treatment of dentinal

hypersensitivity.

The Confocal Laser Scanning Microscope (CLSM) is an optical microscope

that includes a laser light as a light source and an electronic system which helps on

image processing. It obtains high-resolution and extremely thin optical image

sections, removing the interference caused by the light arriving from the different

optical fields across the thickness of the sample and focusing on a single plane

(confocal). Therefore, since the images obtained are digital images, unsuspected

magnifications for optical microscopy can be obtained. CLSM images are notably

higher than those obtained with the conventional optical microscope because the

generated images contain volumetric and texture details impossible to obtain with the

conventional ones. CLSM is a promising imaging method, which enables the

researchers to observe varnish penetration beneath the hard tissues without any

destruction of samples. This systems track fluorescently labelled agents throughout

biological specimens. Depth of penetration of dye in dentinal tubules is obtained by

CLSM image which provide vital details of dentinal hypersensitivity so CLSM is

choosen for current study to evaluate the degree of dye penetration for dentinal

hypersensitivity.31

Scanning Electron Microscope (SEM) allows the visualization of images at

high magnification (50x -10,000 x). In this technique, an electron beam scans the

surface of the sample to produce a variety of signals, the characteristics of which

depend on many factors, including the energy of an electron beam and the nature of

the sample, since a beam of electrons hit the sample and the response is collected by a

detector, as described by Saghiri et al. There is no usage of light and color of sample

does not influence on the image, which is something very important in dentistry,

where dental tissues and dental materials tend to be white or have light colors, which

makes the usage of optical microscopes hard. SEM is used to assess the volume of

dentinal tubules occlusion per square millimeter after the irradiation of Er:YAG laser

Discussion

Page | 36

and sodium fluoride varnish which is useful to know the diameter of tubule occlusion

and number of open dentinal tubules to assess the degree of dentinal

hypersensitivity.32

This study was performed in in-vitro conditions, further long-term in-vivo

studies are required to evaluate the effect of combination of Er:YAG laser and sodium

fluoride varnish in the treatment of dentinal hypersensitivity.

Conclusion

Page | 37

CONCLUSION

Within the limitation of this study of this in vitro study,it can be concluded

that,

1. All the treatment modality for reducing dentinal hypersensitivity were

effective for the occlusion and narrowing of dentinal tubules.

2. The more prominent occlusion was observed in the combined treatment of

Er:YAG laser and sodium fluoride varnish on dentinal hypersensitivity.

3. Therefore, whether used alone or in combination of Er:YAG laser and sodium

fluoride varnish, Er:YAG laser irradiation is effective for the treatment of

dentinal hypersensitivity.

Summary

Page | 38

SUMMARY

Dentin hypersensitivity is a common occurrence and a concern among

patients. It is characterized by short, sharp pain arising from exposed dentin in

response to stimuli, typically thermal, evaporative, tactile, osmotic, or chemical and

which cannot be ascribed to any other dental defect or disease. The two most common

pathways that lead to dentin exposure and dentin hypersensitivity are gingival

recession and enamel erosion.

Er:YAG lasers are effectual in both medical and dental applications because of

having a thermomechanical ablation mechanism and because of the high absorption of

their wavelength by water. The mechanism of Er:YAG laser is the occlusion, by

partial melting, of the exposed dentinal tubules after low intensity irradiation, also, an

analgesic effect of laser irradiation on pulpal nerves may be implicated in the instant

desensitization.

Sodium fluoride gel (NaF), which belongs to the tubule-occluding agents

family is the most commonly used agent by clinicians. This agent’s primary

mechanism relies on the mechanical occlusion that is accomplished by precipitation

of insoluble calcium fluoride crystals within the tubules without adhesion and thus

this agent cannot resist the stresses of the oral environment and degrades over time.

So the combined effect of laser and sodium fluoride varnish is used in current study.

The present study was done to compare and evaluate the combined occluding

effect of sodium fluoride varnish and Er:YAG laser irradiation on dentinal tubules

through scanning electron microscope and confocal laser scanning microscopy. In the

present study forty five extracted maxillary premolar teeth were collected. A 3-mm-

thick horizontal slice was prepared from the cemento-enamel junction of each tooth

using a slow-speed diamond saw. Each slice was transversely separated into two

halves as buccal and lingual. Ninety samples was obtained and these samples was

randomly divided into six equal groups. Groups A, B, C and D was used for the

evaluation of tubule occlusion with SEM. Groups E and F was separated for dentin

permeability with CLSM.

Groups B, D, E and Group F were applied with sodium fluoride varnish and

Group C, D and Group F was irradiated using a Er:YAG laser. The dentine specimens

was irradiated with an Er:YAG laser with a straight quartz round tip of 600 µm

diameter at an energy level of 60 mJ/pulse and a repetition rate of 30 Hz, without

Summary

Page | 39

water irrigation. The laser beam was swept in a mesio-distal fashion for 10 sec with

the beam directed perpendicularly to the dentine surface in non-contact mode at a

distance of 3–4 mm.

Topical sodium fluoride applied to the samples of groups E and F was labelled

with Rhodamine B isothiocyanate dye to determine the effect of different methods

over the penetration depth of the potassium fluoride varnish. CLSM was used in

fluorescent mode to obtain images. A Helium-neon laser was used as the light source.

Groups A, B, C and D was washed with deionised water and gently dried with

air by using a three-in-one syringe. The samples was coated with a thin layer of gold

(20–30 nm) under vacuum in an ion-sputtering device in order to increase

conductivity. SEM images was recorded. Image analysis were performed at 2000x to

determine the diameter of the open tubules.

Normality of tubules diameter and depth of penetration of die in dentinal

tubules scores was statistically analysed by Kolmogorov Smirnov test. The tubules

diameter and depth of penetration of die in dentinal tubules scores follows a normal

distribution. Therefore, the parametric one way ANOVA followed by Tukeys posthoc

procedures and independent tests were applied. Comparison of four study groups (A,

B, C and D) with respect to mean tubules diameter scores was performed by one way

ANOVA. The p value is 0.001.

Pair wise comparisons of four study groups (A, B, C and D) with respect to

mean tubules diameter scores was performed by Tukeys multiple posthoc procedures.

Difference between two groups was found to be statistically significant. Comparison

of two study groups (E and F) with respect to mean depth of penetration of die in

dentinal tubules scores was performed by independent t test. The group E shows

highest dept of penetration of die in dentinal tubules than group F.

Results of the current study shows that combination application of sodium

fluoride and Er:YAG laser on dentinal tubules is the best treatment option for dentinal

hypersensitivity than the application of sodium fluoride varnish and Er:YAG laser

alone.

Bibilography

Page | 40

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P.M.N.M Dental College and Hospital, Bagakot

Department of Conservative Dentistry and Endodontics

WRITTEN CONSENT

Dear Sir / Madam,

This is to inform you that your extracted teeth will be stored and used for a research

study being conducted by Dr. SAHIL R. KAWLE, Post graduate student, Department of

Conservative Dentistry and Endodontics, P.M.N.M Dental College, Bagalkot.

Your participation in the research is voluntary.

Dr. SAHIL R. KAWLE

PG Student

Department of Conservative Dentistry and Endodontics

P.M.N.M Dental College, Bagalkot.

Name of the patient:

Age:

Sex:

Contact:

Dear doctor,

I have no objection to donate the extracted teeth for research purpose and I hereby give my

voluntary consent.

Date and time:

Place:

“A COMPARATIVE EVALUATION OF THE COMBINED OCCLUDING EFFECT OF

SODIUM FLUORIDE VARNISH AND ER:YAG LASER IRRADIATION ON

DENTINAL TUBULES-A CONFOCAL LASER SCANNING MICROSCOPE AND

SCANNING ELECTRON MICROSCOPE- AN IN VITRO STUDY.”

PROFORMA

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GROUP A

GROUP B

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GROUP C

GROUP D

GROUP E (SODIUM FLUORIDE) DEPT OF PENERATION OF DIE IN

DENTINAL TUBLES

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GROUP F (SODIUM FLUORIDE +

Er:YAG LASER)

DEPT OF PENERATION OF DIE IN

DENTINAL TUBULES

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Scanned by CamScanner

COLOUR PLATE 1

Teeth specimens for study

Tooth section of specimens

STUDY SPECIMENS

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Armamentarium

Er:YAG Laser

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Tooth Sectioning Sodium Fluoride varnish

Application

Rhodamine B dye Application Er:YAG Laser Application

PROCEDURE

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Scanning Electron Microscope

Confocal Laser Scanning Microscopy

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GROUP A SEM IMAGE GROUP B SEM IMAGE

GROUP C SEM IMAGE GROUP C SEM IMAGE

SEM IMAGES

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GROUP E CLSM IMAGE

GROUP F CLSM IMAGE

CLSM IMAGES

a comparative evaluation of the combined occluding …

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