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Journal of International Oral Health 2016; 8(4):476-480Bonding challenge for fluorosed teeth… Marure PS et al

Review ArticleReceived: 22nd October 2015 Accepted: 25th January 2016  Conflict of Interest: None

Source of Support: Nil

Orthodontic Bracket Bonding Challenge for Fluorosed TeethPravinkumar S Marure1, Avinash Mahamuni2, Anand S Ambekar3, Suresh Kangane4, Yatish Joshi1, Chaitanya Khanapure5

Contributors:1Associate Professor, Department of Orthodontics, MIDSR Dental College and Hospital, Latur, Maharashtra, India; 2Professor, Department of Orthodontics, SMBT Dental College. Amrutnagar, Sangamner, Ahmednagar, Maharashtra, India; 3Professor, Department of Orthodontics, MIDSR Dental College and Hospital, Latur, Maharashtra, India; 4Professor and Head, Department of Orthodontics, MIDSR Dental College and Hospital, Latur, Maharashtra, India; 5Senior Lecturer, Department of Orthodontics, MIDSR Dental College and Hospital, Latur, Maharashtra, India.Correspondence:Dr. P S Marure. Department of Orthodontics, MIDSR Dental College and Hospital, Vishwanathpuram, Ambajogai Road, Latur, Maharastra, India. Phone: +91-9404366634. Email: drpravinkumar08@gmail.comHow to cite the article:Marure PS, Mahamuni A, Ambekar AS, Kangane S, Joshi Y, Khanapure C. Orthodontic bracket bonding challenge for fluorosed teeth. J Int Oral Health 2016;8(4):476-480.Abstract:Dental fluorosis is a developmental disturbance of dental enamel, caused by successive exposures to high concentrations of fluoride during tooth development, leading to enamel with lower mineral content and increased porosity. Fluorosis, which seriously adversely effects, is not only the teeth and bones but also damages the DNA and chromosomes, resulting in the genetic mutations which may prove very damaging to the health of an individual. The damage caused by fluorosis is permanent, making prevention very important in regions of the world, where the problem is endemic like Pakistan, India, and China. Fluorosis appears to be especially common in the developing world. The severity of dental fluorosis depends on when and for how long the overexposure to fluoride occurs, the individual response, weight, degree of physical activity, nutritional factors, and bone growth. Esthetics changes in permanent dentition are the greatest concern in dental fluorosis, which is more prone to occur in children who are excessively exposed to fluoride between 20 and 30 months of age. It is also important to remind that the critical period to fluoride overexposure is between 1 and 4 years old, and the child would not be at risk around 8 years old. Fluorosis can be prevented by monitoring the amount of fluoride that children up to 6 years old are exposed; therefore, the dentist must be aware of the main sources of fluoride to prevent fluorosis and instruct parents or caregivers on how daily dose should be managed to achieve success in prevention. Bonding of orthodontic brackets to fluorosed enamel is a challenge for all dental clinicians. The objective of this case report is how to manage dental fluorosis patients for the success of orthodontic bracket bonding by the use of microabrasion technique. The recommended microabrasion protocol saves chair side time of the orthodontist, improves the success rate of the treatment and minimizes the cost of the treatment by preventing recurrent bond failures.

Key  Words: Bond failure, bracket bonding, dental fluorosis and microabrasion

IntroductionTooth discoloration may be classified as intrinsic, extrinsic, and a combination of both.1 Intrinsic discoloration occurs following a change to the structural composition or thickness of the dental hard tissues. Extrinsic tooth discoloration is caused by aging, microcracks in the enamel, tetracycline medication, restoration, dental caries, and excessive fluoride ingestion.2 Excessive fluoride intake in drinking water, >1-2 ppm, can cause metabolic alteration in the ameloblasts, resulting in a defective matrix and improper calcification of teeth.3

Diagnosis of dental fluorosisThe adequate diagnosis of fluorosis requires inspection of dry and clean dental surfaces, under a good light source. A fluorosed tooth shows a hypomineralized, porous sub-surface enamel, and acid-resistant well-mineralized surface layer Chalky white appearance. Fluorosis can be prevented by having an adequate knowledge of the fluoride sources, knowing how to manage this issue and therefore, avoid overexposure.1-3

Many parts of India are endemic for fluorosis. Nalgonda district of Andhra Pradesh is one such area, where the concentration of fluoride in the drinking water ranges from 1.5 to 5 ppm in some regions to as high as 31.3 ppm in others.4,5

Bonding of orthodontic brackets to fluorosed enamelIt has been emphasized that the most challenging for orthodontists is bonding brackets to fluorosed teeth because of frequent bracket failure at the compromised enamel interface.6 The fluorosed enamel surface challenges orthodontists even more than bonding brackets to gold, amalgam, and porcelain.7 To get an effective bonding clue for this pretty good quantum of patients who pose a great challenge in orthodontics, in terms of poor shear bond strength of adhesives due to repeated bond failures while using “standard etching protocol,” resulting in a poor treatment outcome. The current orthodontic literature hints that among the various orthodontic adhesive materials, self-etching primer has so far played a promising role in these cases, as is evident from various studies.8

Adhesive procedures require properly integrating multiple interrelated steps in the restorative process, increasing the

Doi: 10.2047/jioh-08-04-13

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Journal of International Oral Health 2016; 8(4):476-480Bonding challenge for fluorosed teeth… Marure PS et al

potential for error.9 Fluorosed enamel demonstrates an outer hypermineralized and acid-resistant layer, where it is difficult to bond brackets because a reliable etched enamel surface cannot be produced.10,11 Dental fluorosis can also influence shear bond strength (SBS) of the orthodontic brackets. A significant decrease in SBS was reported when orthodontic brackets were bonded on fluorosed teeth.12-14 Repeated bracket bonding is time-consuming and has a negative effect on successful orthodontic treatment. Some investigators have recommended enamel microabrasion with aluminum oxide powder to fluorosed enamel to remove the acid-resistant hypermineralized surface layer and increase orthodontic bracket bonding efficiency.15-17

Recently, ultra-short pulsed lasers have been used to prepare teeth before orthodontic bonding procedures. These lasers can be focused on the tooth surface with exceptional precision and reproducibility resulting in the ablation of thin layers of enamel without much damage to the adjacent enamel or causing vibration or heating.18

Enamel microabrasion techniqueMicroabrasion technique involves the removal of a small amount of surface enamel with abrasion powder with a dental instrument, Microetcher II (Figure 1). Microabrasion is

indicated for fluorosed teeth before bracket bonding, post-orthodontic demineralization, localized hypoplasia due to infection or trauma, and idiopathic hypoplasia where the discoloration is limited to the outer enamel layer.7

Clinical case reportA healthy 17-year-old female patient presented for orthodontic consultation with chief complaint of the gap between teeth, protrusion and difficulty sealing her lip. There was no contributing medical or dental history. Patient oral hygiene was good and temporomandibular function was within normal limits. The initial clinical examination revealed moderate spacing in the upper arch and congenital missing right maxillary canine with mild crowding in the lower arch associated with generalize fluorosis in the both upper and lower arch (Figures 2 and 3).

Diagnosis and treatment planA facial analysis revealed convex profile with bimaxillary incisor protrusion. A lateral cephalogram revealed a mild skeletal Class I with horizontal growth pattern. Dental Class I malocclusion with spacing in upper arch associated with 4 mm of overjet and overbite and maxillary right canine was congenitally missing.

Fixed orthodontic treatment was planned in the patient to close the spacing in maxillary arch and alignment in the mandibular arch using MBT 0.002” Pre-adjusted edgewise appliance. The additional step of microabrasion/microetching was done before routine etching of enamel before bonding of orthodontic appliance using Microetcher II (intraoral microabrasion using 50 µm of aluminum oxide).

The following microabrasion protocol was done: All teeth were polished with pumice and water slurry. Teeth isolation was done with a rubber dam (Figure 4a), and microabrasion was performed using microabraded with 50 µm of aluminum silicate for 5 s (Figure 4b). 37% phosphoric acid etchant were then placed on the air-abraded enamel surface with a syringe applicator for 30 s. The etchant was thoroughly washed with water for 10 s followed by air-drying for 10 s.Figure 1: Microabrasion dental instrument, Microetcher II.

Figure 2: Pre-treatment extra-oral photos showing incompetent lip seal and convex profile. (a) Front photo at rest, (b) front photo on smile, (c) profile view.

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Bonding challenge for fluorosed teeth… Marure PS et al Journal of International Oral Health 2016; 8(4):476-480

An adhesion promoter Primer (3M Unitek) was applied and gently air dried for 5 s, followed by light curing for 10 s with a visible white light unit. 3M Unitek Transbond XT adhesive placed on the base of the bracket and light cured for 60 s.

The patient was initiated with 0.016” Nitinol archwire for alignment (Figure 5). After alignment, final leveling and finishing of the case was done with 0.019 × 0.025” stainless steel archwire (Figure 6). Interproximal slicing was done to align mandibular teeth. It was found that during orthodontic treatment patient never came with debonded brackets and also acceptable treatment result was achieved. Care was taken to maintain space for prosthetic replacement of right maxillary canine.

Treatment resultsThe main request of the patient was to close space and reduce protrusion, improve sealing of her lips and balance her profile. The final result showed good alignment, occlusion, ideal overbite and overjet and the patient is happy with the orthodontic treatment results (Figures 7 and 8), and cephalometric analysis suggesting acceptable dental inclination and soft tissue profile achieved (Table 1).

DiscussionDental fluorosis is not only a major esthetic concern but also highly challenging and expensive condition to treat. If left untreated, it can cause embarrassment for the school-aged

children, resulting in psychosocial distress, difficulties in societal adjustment, and damage to the self-esteem of the patient. They are teased by their peers, usually adapt avoidance behavior when to meet others, put hand before his mouth while smiling. They lack initiative due to compromised confidence level.2,3,7

It is well known that normal fluoride level is an important dietary supplement, which has been proven effective in preventing dental caries. It is, however, the excessive fluoride which damages ameloblasts as was evident from the present study sample. Crippling of these cells jeopardizes not only the mineralization process of the teeth but also increases the porosity of the sub-surface of enamel. Thus, dental fluorosis in its more advanced stages can leave teeth more susceptible to increased caries lesions because of pitting and loss of the outer enamel.19

As stated earlier, the long term over-intake of fluoride may cause skeletal as well as dental fluorosis. Many studies on other toxic effects of fluoride have been made and including whether it alters the human genetic material and ultimately leads to more serious harm.20

ConclusionsMicroabrasion promotion heralds new and improved options for orthodontists when dealing with the clinical dilemma of bonding to fluorosed and hypocalcified enamel. The results of this case report have provided encouraging clinical evidence of bonding to fluorosed teeth.

Use of microabrasion method increases micromechanical orthodontic bracket retention of severely fluorosed human teeth and provides a clinically successful adhesive bonding protocol.

Public awareness campaign both at School, Masjid and Community level is to be mobilized. Children and adults inflicted with fluorosis and should be given treatment priority,

Figure 3: Pre-treatment intra-oral photos showing generalized fluorosis, midline diastema and congenitally missing right maxillary canine. (a) Upper arch occlusion view, (b) lower arch occlusion, (c) front view, (d) right side occlusion, (e) left side occlusion.

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Figure 4: (a) Isolation of teeth with a rubber dam, (b) microabrasion was performed using microabraded with 50 µm of aluminum silicate for 5 s.

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Journal of International Oral Health 2016; 8(4):476-480Bonding challenge for fluorosed teeth… Marure PS et al

so as to minimize or disguise their staining stigma and pitting abnormalities of the teeth. Restoring their smiles through

dental esthetics will help them in gaining self-esteem and confidence level.

Figure 5: Patient was initiated with 0.016 nitinol archwire for alignment. (a) Right side view, (b) front view, (c) left side view.cba

Figure 6: Final leveling and finishing of the case was done with 0.019 × 0.025” stainless steel archwire. (a) Right side view, (b) front view, (c) left side view.

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Figure 7: Post-treatment extra-oral photos showing pleasant smile and acceptable profile, (a) Front photo at rest, (b) front photo on smile, (c) profile view.

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Figure 8: Post-treatment result showing good alignment, occlusion, ideal overbite, and overjet. (a) Upper arch occlusion view, (b) lower arch occlusion view, (c) front view, (d) right side occlusion, (e) left side occlusion.

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Table 1: Cephalometric analysis.Parameters Norms Pre‑Rx Post‑RxSNA 82° 84.5° 82°SNB 80° 83° 81°Co-Gn (mm) 118 119 120ANB 2° 1.5° 1°NA-Pog 0-5° 3° 1°Beta angle 27-35° 40° 34°Wits (mm) 1 5 2SN-GoGn 32° 20° 28°F-M-A 25° 18° 24°U1-SN 102° 123° 108°U1-N (mm) 2-4 7 4U1-NA 22° 30° 23°L1-FH 65° 51° 62°L1-N Pog (mm) 4 5 4L1-NB (mm) 4 7 6IMPA 95° 109° 96°Nasolabial angle 102° 76° 100°Overjet (mm) 2 4 2Overbite (mm) 2 4 2