PEDIATRIC DENTISTRY/Copyrights 1981 byThe American Academy of PedodonticsVol. 3, Special Issue

Concept and practice of plaque-control

Per Axelsson, Odont D

AbstractThe effect of plaque control on gingivitis

and periodontitis is well-documented. In short-terminvestigations, chemical plaque control (oral rinsing twice aday with 0.2% chlorhexidine-gluconate solution) has beeneffective in the prevention of human gingivitis.Experimentally produced human gingivitis heals completelywithin one week when the same method is employed.

Tooth cleaning with oral hygiene aids every other dayprevents the initiation of gingivitis. Cleaning every third orfourth day, on the other hand, prevents neither thedevelopment nor the persistence of gingivitis.

A combination of oral hygiene instructions andmechanical professional tooth cleaning at proper intervalscan almost completely prevent the development of bothgingivitis and periodontitis. In crossover studies and studiesbased on the "split-mouth " technique, frequent mechanical,professional tooth cleaning is superior to oral hygieneinstructions assuming the same frequency.

Finally, it must be stressed that the effect of home careand professional tooth cleaning on gingivitis andperiodontitis differs radically when ordinary tooth cleaningis concentrated on the "key-risk" as opposed to the "non-risk " surfaces.

Definition of Dental Plaque

Dawes et al. 19631 described plaque as the soft,tenacious material found on tooth surfaces which isnot readily removed by rinsing with water.

The most clinically observable plaque on thesmooth surfaces of the teeth along the gingival marginmay be termed dentogingival plaque. Dentogingivalplaque which occurs on the approximal surfaces, api-cal to the contact points, is termed approximal dentalplaque. Plaque may be found below the gingival mar-gin in the gingival sulcus or in the periodontal pocketand is termed subgingival plaque.2 We normally willfind non-attaching bacteria in the most apical positionof the periodontal pocket.3

In children and adults up to 40 years of age, inter-proximal dental plaque is mainly subgingival becausethe gingival papilla normally fills up the interproximalspace. In spite of some loss of periodontal attachment,

the papilla will fill up the interproximal space due toedema.

After tooth cleaning, the supragingival plaquealong the gingival border of the teeth reaccumulatesslowly during the following two days. The thickness ofthe plaque increases dramatically after the third day,to a maximum after seven days.w

Etiology of Periodontal Disease

In 1965, Lbe and associates7 demonstrated thatclinical symptoms of gingivitis developed in studentswith clinically healthy gingiva within two to threeweeks if dental plaque was allowed to freely accumu-late. If adequate tooth cleaning was resumed, the gin-gival inflammation cleared up within a week.

Subclinical symptoms of gingival inflammation inthe form of a discharge of exudate from the gingivalsulcus appear within four days if plaque is allowed toaccumulate freely in the dentogingival region.8

Page & Schrbder9 have demonstrated that an initialgingival lesion develops within approximately fourdays from a condition of healthy gingiva if plaque isallowed to accumulate freely. Lang and associates10

demonstrated in 1973 that students who completelyfreed their teeth of plaque at least every other day,did not develop clinical symptoms of gingival inflam-mation over a six-week period. On the other hand,those students who cleaned their teeth only everythird or fourth day all displayed signs of gingivitis. Ifgingivitis remains untreated, there is a gradual in-crease in the edema in the gingiva. The subgingivalmicroflora undergoes a gradual transformation into apreponderance of gram-negative anaerobic rods —straight, curved and mobile.

Saxe et al.,11 Lindhe and associates12 have demon-strated that gingivitis induced by bacteria, if leftuntreated, gradually results in periodontitis.

Today the interest in certain bacteria in the subgin-gival microflora associated with etiology of periodon-titis is concentrated on: Bacteroides asaccharolyticus,Fusobacterium nudeatum, Actinomyces israelii, Eike-

PEDIATRIC DENTISTRY

Voluma 3, Special Issue101

nelIa corrodens, Caplmocytophaga sputigena andActinobacillus actinomycetemcomitans. The last twotypes of bacteria are especially associated with juve-nile periodontis,m4

Prevention of Periodontal Disease

There is overwhelming evidence indicating thatcomplete removal of bacterial plaque from the dento-gingival region is the most effective method ofpreventing gingivitis and periodontitis. Control of per-iodontal disease by eliminating pathogenic organismsof the microflora is, as yet, impossible, but it is theo-retically an attractive approach.

Based on epidemiological studies there is a verystrong correlation between the localization of dento-gingival plaque and periodontal disease. 1.1~ Epi-demiological studies clearly show that there are cer-tain key-risk-teeth (molars and premolars) and key-risk-surfaces (the proximal surfaces of the molars andpremolars)Y= FfLrthermore, 13- to 16-year-old Swed-ish children are the "key-risk age-groups" regardingthe progression of dental caries disease in the perma-nent dentition. In the same age group we find around20% "key-risk individuals."

Clinical studies carried out by Bj6rn and cowork-em have showed that 75% of all interproximal fillingshave overhangs in a subgingival position. Also, theyfound that the loss of periodontal attachment at thesame tooth-surface was correlated to the size of theoverhang as an effect on increased plaque retention.~

Hence, successful caries prevention will also result inthe prevention of periodontal disease.

The basic principle for preventive dentistry mustbe that the preventive measures will give the most sig-nificant effect if we concentrate them on "key-risk agegroups," "key-risk individuals," "key-risk teeth" and"key-risk surfaces." That means preventive programsbased on plaque control have to be concentrated onthose tooth surfaces where the risk for development orprogress of dental disease is most pronounced in agiven population.

Definition of Plaque Control

Plaque control normally means preventive meas-ures aimed at removing dental plaque and preventingit from recurring. This can be accomplished eithermechanically or chemically: sometimes the two pro-cedures are combined.

Home Care

"Home care" means the sum effect of motivation,knowledge, oral hygiene instruction, oral hygiene aidsand motor skill.

Today, toothbrushing and other mechanical cleans-ing procedures are the most reliable means of control-ling plaque at home. In Scandinavian countries almost

100% of the school-children brush their teeth once ortwice a day.

A Swedish surveyu showed that no less than 99.5%of all adults with their own teeth use a toothbrush asan oral hygiene aid. However, only 70% of men use atoothbrush daily from the age of 30, whereas 85-90%of women use a toothbrush daily. Nonetheless, indus-trious use of the toothbrush is not synonymous withtooth cleaning.

In 1971, Hansen & Gjermou carried out an investi-gation with the object of evaluating the plaque remov-ing effect of various toothbrushing methods on indi-vidual tooth surfaces. The subjects of the experimentallowed plaque to accumulate freely for three days.Then a dental hygienist, using an ordinary tooth-brush, tested the cleaning effect of the roll-brushingmethod, the Bass method, Charter’s method, and theeffect of an interspace brush. The cleaning effect ex-pressed in terms of Silness & LSe’s plaque-index isvery modest for all methods of brushing despite thefact that brushing was carried out by a dental hygie-nist. Similar findings, have recently been discovered ina study by Bergenholz and coworkers.=

There is a strong correlation between brushing fre-quency and the reduction in plaque/gingivitis on thebuccal surfaces. The vast majority of self-taughttoothbrushers begin by scrubbing the buccal surfaces,especially at the frontal region, and rarely proceed tothe lingual surfaces. Interproximal cleaning is simplynon-existent in the self-taught.

Most oral hygiene brochures say that tooth clean-ing should begin with the use of a toothbrush andtoothpaste on the buccal surfaces, followed by the lin-gual surfaces of the upper jaw teeth. Then the buccalsurfaces of the lower jaw teeth should be brushed, andfinally, the brush should be used on the lingual sur-faces of the lower jaw teeth. Only then is interdentalcleaning considered appropriate. However, there is noodontological necessity for this cleaning order of indi-vidual teeth surfaces.

The level of ambition is always greatest at the be-ginning of a tooth cleaning operation. Moreover, moretoothpaste is on the toothbrush in the initial phaseand the brush bristles are most rigid. In the buccal re-gion, the alveolar bone is very thin and may even beabsent altogether -- on the buccal surfaces of the ca-nines for example, in the lingual and palatine regions,however, the alveolar bone is normally very strong.

In light of all these factors, it is evident that therisk of inflicting traumatic lesions during tooth clean-ing is very great if one decides to begin the operationwith the buccal surfaces of the upper jaw teeth. More-over, far too many people gradually switch from a cor-rect Bass method to a horizontal scrubbing method asthe interval since the time of instruction increases.This again increases the risk of tooth cleaning trauma

PLAQUE-CONTROL102 Axelsson

on the most prominent sections of the buccal surfaces.As a result, there is a very positive correlation be-

tween brushing frequency, gingival retraction andtrauma caused by an abrasive lesion on the buccal sur-faces.~

Up to the age of 25, the greatest loss of periodontalattachment is found on the buccal surfaces in theaverage patient. This is brought about principally bytoothbrushing, and is particularly unfortunate incases where the bifurcations have been exposed on thebuccal surfaces of the molars, indirectly causing rootseparation or extraction.

A fundamental principle for all preventive action isthat the positive effect is greatest where the risk ofdisease development is greatest. Figure 1 shows wherethe "key-risk surfaces" are located in the dentition.The patient has the greatest chance of being able tosee positive results in his oral hygiene efforts if he con-centrates initially on "key-risk teeth" and "key-risksurfaces." After this we can make more stringent oralhygiene demands by including buccal surfaces whereresults are largely indiscernible.

A Swedish survey shows that approximately 46% ofadults use toothpicks sporadically. Of these, 12% usetoothpicks daily. On the other hand, dental floss isused irregularly by 12% of adults, and 2% of these usedental floss daily. In other words, toothpicks are usedsix times more frequently than dental floss as an oralhygiene aid by adults!

Despite this, it must be recognized that interdentalcleaning is practically non-existent as an establishedhabit in most countries. In the light of normal plaquedistribution and dental disease in the dentition and on

individual tooth surfaces, we can therefore state thatneeds-related tooth cleaning does not take place. Theaspirations of the adult patient today focus princi-pally on those tooth surfaces with the least diseaseformation, and cleaning, therefore, only produces ap-proximately a 20% effect. In other words, there is alargely unexploited source of dental care here whichwe must tap. Yet out of 8760 hours per year, the indi-vidual patient normally spends no more than twohours in the dental clinic.

Needs-Related Tooth Cleaning at Homeup to 1 1 Years of Age

When using needs-related tooth cleaning on chil-dren under eight years old, interdental cleaningshould concentrate on the distal surfaces of the decid-uous second molars and the mesial surfaces of the firstpermanent molars. A dental floss holder may facilitatematters for the parents doing this for their children.

Unfilled fissures in the molars are next in line forneeds-related toothbrushing. A soft, compact tooth-brush and normal abrasive toothpaste with fluorideshould be used for this purpose. (If parents carry outcleaning of this type on children under the age ofeight, an interdental brush can also be used to advan-tage.) A suitable toothbrush for these age groups has small head with a handle designed for an adult hand,since the cleaning is preferably done by adults.

Needs-related tooth cleaning of the lingual andbuccal surfaces should therefore commence in the lin-gual position in the lateral segments of the lower j aw.The risk of traumatic tooth cleaning lesions is alsolower on the lingual surfaces of the lower jaw than on

15 YEARS 25 YEARS 50 YEARS

Figure 1. Location of "key-risk surfaces" in the dentition.

PEDIATRIC DENTISTRY 103Volume 3, Special Issue

the buccal surfaces of the upper and lower jaws due tothe presence of thick alveolar bone and linguallyinclining teeth.

Needs-Related Tooth Cleaning at HomeFrom 12 to 16 Years of Age

Needs-related tooth cleaning at this age shouldbegin with interproximal cleaning of the lateral seg-ments up to the distal surfaces of the canines. Themost suitable oral hygiene aid is dental tape with orwithout a dental floss holder. When flat, waxed tape isused, the "rubbing method" is most effective. Thismethod is easy to learn and can be combined withtoothpaste. If there is a large number of filled inter-proximal surfaces, toothpicks might also be appropri-ate. Bitewing X-ray photographs of the lateral seg-ments should be used as a guide in selecting a suitableoral hygiene aid for interproximal areas.

According to an in vivo study by Badersten andEgelberg~ designed to evaluate the plaque-removingeffect of toothpaste during toothbrushing, the tooth-paste resulted in a 50% increased effect. It is clear thattoothpaste should also be used interdentally in themolar and premolar regions.

Needs-Related Tooth Cleaning at Home for Adults

Figure 2 shows the average 25-year-old Swedish in-habitant’s oral health status. The loss of periodontalsupport is 1 mm on the average and is localized mainlyon the buccal surfaces. It may be assumed that fillingand cavity margins in the interproximal areas arelocated subgingivally and that subgingival plaque isfound on the remainder of the filled interproximalsurfaces.

Waerhaug has shown in vivo, and on autopsycorpses, that you can maintain the subgingival regionsfree of plaque to a depth of 2 to 3 mm because of theresilience of the gingival papilla by using a triangulartoothpick inserted interproximally, Figure 3. This al-lows cleaning to take place apically to the margins offillings located subgingivally -- surfaces where recur-rent caries can develop. Open interproximal spaces arevery common among the normal adult clientele.Toothpicks, or the equivalent, are the most appropri-ately designed oral hygiene aid for open interproximalspaces. (In the process of filling a tooth interproxi-mally, a toothpick or the equivalent can be used as awedge to guarantee a correctly shaped interproximalspace, since toothpicks, or V-shaped parts of mechani-cal prophylactic aids, are normally used for inter-dental oral hygiene.) The bitewing radiograph can actas a guide in selecting a suitable oral hygiene aid forinterdental cleaning.

Figure 2 shows that the exact moment when thegingival papilla is depressed is definitely the best timeto utilize the cleaning power of toothpaste as a fluo-

Figure 2. 2 to 3 mm subgingival cleaning with toothpick. (J Waer-haug).

ride-bearer during needs-related tooth cleaning.The occurrence of interproximal plaque distal to

the canines is most frequently underdia~osed up tothe age of 40, despite the use of a disclosing agent.This is because the gingival papillae completely fill upthe interproximal spaces in the premolar and molarregions and obstruct disclosing solution vision. Thefew exceptions are those patients under ’Lhe age of 40who have exposed interproximal surfaces because ofadvanced periodontitis.

Because the interproximal spaces in the premolarand molar area normally have a wider triangularopening from the lingual side it is very important touse triangular pointed toothpicks from a lingual direc-tion to get the best plaque removal. Tiffs procedurecan be carried out more comfortably and properly ifthe toothpick is fixed in a handle. Needs-related toothcleaning in adults ought to start interproximally froma lingual position in the molar area of the lower jaw.

In individuals with advanced periodontal diseasewe find a relatively large number of wide interdentalspaces and partially exposed root surfaces. The inter-dental brushes usually have the greatest cleaningeffect in wide interproximal spaces. The effect wouldprobably be enhanced if the brush were triangular incross section instead of round (Figure 3). If there areexposed root surfaces in the interproximal area, cau-tion should be used with abrasive toothpaste.

PLAQUE-CONTROL104

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How to Establish Oral Hygiene Habits Focused onthe Localization of Dental Plaque and Dental Disease?

The fundamental precondition of establishingneeds-related tooth cleaning habits is a patient who issufficiently motivated, informed, and instructed.

Since established habits are reliable, the new habitswe want to establish should be linked very firmly tohabits already established. The new habit should al-ways be done immediately prior to the establishedhabit. These principles are known as the linkingmethod and have been described by Weinstein andGetz.~

The linking method may be used in practice as fol-lows: If the patient has irregular oral hygiene habits,you should take advantage of habits already estab-lished to link with those times we wish the oralhygiene procedures to be performed. For example, ac-cording to the linking method, the oral hygiene proce-dure should be performed immediately prior to thedaily morning shower and evening news.

Although more than 80% of all adults brush theirteeth daily, there are practically no daily interdentaltooth cleaning habits. As we have seen, use of thetoothpick is about six times more common amongadults than dental floss or interdental brushes.

According to the linking method, needs-related toothcleaning on adults begins with interdental cleans-ing from the lingual side in the molar/premolar regionof the lower jaw with a toothpick in a handle andmildly abrasive fluoride toothpaste. Following this,the interproximal surfaces of the molar and premolarregions of the upper jaw should be cleaned. A tooth-brush should first be used lingually on the lateral seg-ments of the lower jaw where most people do not effi-ciently use the toothbrush. Therefore, it is important

to begin toothbrushing there when the most tooth-paste is on the brush and the bristles are most rigid.After this the buccal and occlusal surfaces of the lowerjaw should be cleaned. In the upper jaw, cleaning withthe toothbrush can begin on the palatal side, then thebuccal and occlusal surfaces of the molars should becleaned. Needs-related tooth cleaning, following thelinking method toothbrushing, should be carried outin the reverse order from that which we have tradi-tionally recommended for our patients. If interdentalcleaning with toothpick and toothpaste according tothe method described here has become an establishedhabit, this should have such a highly preventive effectthat it may never be necessary to use the interdentalbrush.

Similarly, professional needs-related tooth cleaningshould begin interdentally from the lingual side on thelateral segments of the lower jaw with mechanicallypowered toothpick and fluoride polishing paste.

Agerbaek and associates" did not receive any posi-tive effect on plaque and gingivitis scores in a one-yearstudy including biweekly repeated 20-minute lecturesin preventive dentistry for small groups (eight to tenschool children). The program also included oralhygiene training.

Moreover, there are studies which demonstratethat efforts of this nature do not produce a long-termeffect beyond one month.~,31 If, however, oral hygienemotivation, information and instruction are combinedwith professional tooth cleaning, the effect of theoperation, expressed in terms of plaque and gingivitisvalues, is present after three months;~

From the study described earlier by Lang and asso-ciates1° we know that clinical signs of gingivitis will notoccur during a six-week experimental period if proper

Figure 3. "Tailor-made" interdental brush as it should look.

PEDIATRIC DENTISTRY 105Volume 3, Special Issue

mechanical tooth cleaning, including use of interproxi-mal aids {dental floss and toothpicks) as well as thetoothbrush, is done once every other day.

Figure 4 shows the pattern of plaque distributionaccording to Silness & LSe’s plaque index at differenttooth surfaces in upper and lower jaws if tooth clean-ing procedures are carried out twice a day every day,every third day, or every fourth day.

Score 2 means visible plaque (black). We can seethat almost 100% of the proximal surfaces have visibleplaque immediately before the tooth cleaning everysecond day without inducing clinical signs of gingivi-tis. If the teeth were cleaned only every third orfourth day, gingivitis gradually developed interproxi-mally in the molar area."

Bosman & Powell, ~ in another study, inducedexperimental gingivitis in a group of students. Inthose students who freed their teeth from plaque onlyevery third or fifth day, the symptoms of gingival in-flammation persisted. But in the two groups thatcleaned their teeth properly once a day or every sec-ond day, the gingivae healed within seven to ten days.

We can conclude that proper mechanical toothcleaning including the key-risk surfaces every secondday is superior to daily toothbrushing concentratedmainly on the "non-risk surfaces."

Chemical Plaque Control

Among the chemicals tested so far for their plaqueand gingivitis inhibiting potential, chlorhexidinedigluconate has shown greatest promise for short-termuse.

In 1970 LSe and co-workers~ demonstrated that inthe absence of any form of mechanical hygiene, twodaily mouth-rinses with 0.2% chlorhexidine gluconatecompletely inhibited the development of plaque andgingivitis during a three-week experimental period. Ina two-year study, students who rinsed daily reducedtheir PII from 0.75 to 0.3 and GI from 0.’75 to 0.4.= Inexperimentally-induced gingivitis, Bosman & Powell~

showed that the gingiva healed within five to sevendays when daily 0.2% chlorhexidine mouth rinses wereintroduced. One of the most intriguing characteristicsof chlorhexidine is its selective absorption, to the toothsurface.~ Also, it seems to have a specific antimicrobialeffect on Strep mutans.~,~

Staining of teeth and restorations is a major side ef-fect which excludes chlorhexidine for long-term andpublic health use2,~ For long-term use, fluoride appearsto hold the most promise for preventing gingivitis.

In ~tro studies by Glantz~ have shown that stan-nous fluoride solution reduces the surface energy andthe wettability of the enamel surface. Consequently,the wet weight of attached plaque was reduced. Or-ganic fluorides such as amine fluoride appear to have agreater plaque reducing activity than inorganic fluo-ride. 42 In areas with fluoridated water, the wet weightdental plaque per individual is significantly lowerthan in non-fluoridated water areas. ~3 Topicallyapplied fluorides reduce the amount of plaque~ andthe proportions of Strep mutans.~.~ For reviewsof chemotherapy of dental plaque, see Emilsson,~

Loesche/~ and LSe.~

INDIVIDUAL NO. 11 6 5 29

INTERVAL B~TWEEN 12 HOURS 48 HOURS 72 HOURS 96 HOURSO~AL HYGIENE

MESIAL

FACIAL

LOWER

LOWER

LOWER

LOWER

M PC I C P M M PC I C P M M PC I C P M M PC I C P ki

100Z

UPPER

0 Z 01STAL

LOWER

100 Z~OOZ

UP~£R

O Z MESlAL

LOWER

UPPER

0 Z FACIAL

LOWER

1OOZ

IOOZ

UPPER

Figure 4. Pattern of plaque distribution according to Silness & L~e’s plaque index at different tooth surfaces in upper and lowerjaws when tooth cleaning is done at 12, 48, 72, and 96 hours intervals.

PLAQUE-CONTROL106

Axelsson

Professional Mechanical Tooth CleaningProfessional mechanical tooth cleaning is the selec-

tive removal of supragingival, but also subgingivalplaque, from all tooth surfaces with mechanicallydriven instruments and fluoride polishing paste byspecially trained personnel -- prophy dental nurse,dental hygienist or dentist. It also includes the re-moval of calculus and subgingival plaque. (These latermethods are only performed by dentists and dentalhygienists, and are usually referred to as scaling proce-dure.) Professional mechanical tooth cleaning not in-cluding scaling procedure will be abbreviated asPMTC.

Beginning with 15-year-old patients, interproximalPMTC in molar- and premolar-areas is carried outusing mechanically-driven, pointed, triangular tipswith a speed of 10,000 strokes per minute49 and anabrasive fluoride-containing prophy-paste. As before,needs-related PMTC normally ought to start inter-proximally from a lingual position in the molar area ofthe lower jaw.

In children, dental tape adapted to a holder is theinstrument of choice for interproximal PMTC. Thebuccal and lingual surfaces are normally cleaned usinga rotating rubber cup and the same type of prophy-paste.

Some effects of PMTC: after one single PMTC per-formed by a dental hygienist, the amount of gin-gival exudate diminishes continuously in the first 24-28 hours. The amount of exudate did not return to thepre-experimental level until one week later.~

The new formation of perceptible complex plaquein the dentogingival region may be retarded in a nor-mal patient until 24-30 hours after PMTC, comparedwith about 12 hours after dealing with oral hygieneaids2 In some cases this may have a decisive signifi-cance in possible remineralization of incipient cariesand shallow caries at the microscopic level.

PMTC may completely free all tooth surfaces ofpartially hardened and soft accumulations. Accumula-tions with caries-associated Strep mutsns grow in avery predictable pattern on approximal surfaces, infissures, and generally in association with the initialcaries attack on enamelY,u Since old plaque with anaggregate of Strep mutans is removable completelyfrom all enamel surfaces by PMTC, other non-cario-genic micro-organisms may establish themselves.Strep sanguis, for example, normally re-colonize thetooth surface earlier than Strep mutans.2.~,~7 Frequentlyrepeated PMTC heals the gingiva quickly. This re-suits, indirectly, in a reduced plaque formation rate.Saxton~ has shown that the reaccumulation rate ofgingival plaque is directly correlated to the degree ofgingival inflammation and the quantity of gingival ex-udate. Therefore the patient’s own tooth cleaningwith oral hygiene aids is enhanced by the removal of

the old, partially-mineralized plaque and the reduc-tion of the rate of re-formation of new plaque.

PMTC may also be expected to have a strong pa-tient-motivating effect: The patient experiencesPMTC as a positive treatment form and with varyingsuccess attempts to preserve the clean feeling with hisown oral hygiene aids.

A one-year investigation with adult periodonti-tis patients using PMTC once a month in a randomright or left side {sprit-mouth method) showed a near-corresponding reduction of plaque and gingivitis evenon the untreated side. ~ This strengthens the opinionthat the motivating effect of PMTC should not beunderestimated.

The preventive effect of plaque-control program

on gingivitis and periodontitis is generally accepted.But there is a question as to whether or not the devel-opment of caries can be avoided or reduced by im-proved oral hygiene.5~,~

These considerations were one of the reasons weinitiated a series of longitudinal plaque controlprograms including PMTC in school children to testthe effect of mechanical plaque control on gingivitisand dental cariesY,~

In 1971 a longitudinal clinical trial was initiated totest the hypothesis that gingivitis and dental caries donot develop in school children maintained on an oralhygiene program that included meticulous profes-sional tooth cleaning and oral hygiene instructionsonce every two weeks. Two hundred sixteen childrenwere selected for the study. They were all pupils of thesame elementary school in the city of Karlstad. Theyhad the same socioeconomic background and wereseven to eight, 10 to 11 and 13 to 14 years old at theonset of the study. They were assigned to experimen-tal and control groups by artibtrarily assigning one oftwo classes to the experimental regimen and the otherto the control group.

Following the baseline period, members of the con-trol groups continued a preventive program which in-cluded supervised tooth brushing with a 0.2% sodiumfluoride solution once a month.

The experimental groups of children were sub-

jected to a very intense prophylactic regime. Dentalplaque was stained with 4% erythrocin-disclosing pel-lets and the Bass method of toothbrushing wasdemonstrated for each child. The children were alsoinstructed in interdental cleaning with dental tape.The oral hygiene instructions were repeated as neces-sary at each oral hygiene session.

The vestibular and lingual surfaces of all teeth werecleaned with the aid of a rotating rubber cup. Inter-dental cleaning was carried out with reciprocatinginterproximal tips and dental tape. An abrasive paste

PEDIATRIC DENTISTRY 107Volume 3, Special Issue

containing 5% sodium monofluorophosphate was usedfor all PMTC.

After two years, the intervals between consecutiveprophylactic sessions were extended to either four oreight weeks for the third experimental year. Duringthe fourth and final year, the children received onlyfour to six PMTC. Figure 5 shows the mean PII andGI in the control groups and the experimental groupsat baseline, and the four yearly re-examinations.

Low PII in the test groups after one year was main-rained during the following experimental period andassociated with low GI. In the control groups therewere no significant alterations.

The controls also developed 941 new carious lesionsduring the entire four-year period compared to thetests, who developed a total of only 61 new cariouslesions.

In 1973 a study~1 using the crossover design was ini-tiated at the same school to evaluate the relativeeffect on gingivitis and dental caries of: 1) PMTC;2) Chemical plaque control (Hibitan-Gel); 3)Oralhygiene information and instruction; and 4) Topicalapplication of fluoride.

One hundred sixty four 13- to 14-year-old childrenparticipated in the two-year trial. Following a baselineexamination, the children were randomly divided intofour groups. All participants were recalled to a pro-phy-dental clinic once every two weeks for preventivetreatment.

During the first year Group 1 received a preventiveprogram that included 0.5% Hibitan-Gel applicationevery two weeks, and a 2% monofluorophosphate solu-tion mouthwash and dentifrice with fluoride for homeuse (H + F). Group 2 received a preventive programthat included 0.5% Hibitan-Gel application, distilledwater for mouthwash and placebo dentifrice for homeuse {H). Group 3 received a preventive program simi-lar to that described in the four-year study; PMTC,rinsing with 2% monofluorophosphate solution andfluoride-containing dentifrice for home use (P + F).Group 4 received a preventive program includingPMTC, rinsing with distilled water and placebo denti-frice for home use (P).

During the second year, group 1 received a preven-tive program similar to the regimen followed by group3 during the fLrst year of trial. During the second year,group 2 received a preventive program similar to theregimen followed by group 4 during the first year oftrial. Group 3 received a preventive program that in-cluded oral hygiene instructions, and 2% monofluoro-phosphate mouth wash and dentifrice with fluoridefor home use during the second year of trial {OH +F). Group 4 received a preventive program during thesecond year similar to group 3, but fluoride was ex-cluded. It should be noted that groups 2 and 4 did notreceive fluoride application at any time during thetwo-year period (OH).

PLAQUE-CONTROL108 Axelsson

GI

1.0-

0.5’

1.0’

2.0J

PII

TEST

CONTROL

B L 1972 1973 1974 1975

Figure 5. Mean Pll and GI in the control groups and the experi-mental groups at baseline and the four yearly re-examinations.

During the first year of the trial no alterations oc-curred in either the PII or GI in groups 1 and 2. Thatmeans that Hibitan-Gel used only once every twoweeks had no effect. The preventive program that in-cluded PMTC (groups 3 and 4) resulted in a consider-ably reduced PII and GI. On the average, the PIIdecreased from 69 to 28%, while the GI decreased from23 to 6%.

During the second experimental year groups 1 and2 received a preventive program that included PMTC.The PII decreased from 64 to 23%, the GI from 22 to4%. The reductions in groups 3 and 4 closely paralleledthe previous reductions observed in groups 1 and 2.The significant alteration was due to the addition of apreventive program which included oral hygiene in-struction once every two weeks during the second yearof the trial, similar to groups 3 and 4. The GI and PIIobserved in groups 3 and 4 at the end of the first yearcontinued without significant change.

During the first year 5.8 new carious lesions devel-oped per child in group 1. Group 2 developed 5.3. Only0.3 and 0.4 carious lesions developed in groups 3 and 4respectively. During the second year of the trial chil-dren of groups 1 and 2 developed 0A: new cariouslesions on the average. Reversals of incipient cariouslesions were observed. An average of 1.3 and 1.8 newcarious lesions developed in groups 3 and 4 during thesecond year. At the first follow-up exan~ination therewas no significant difference in caries development be-tween groups 1 and 2, but the difference betweengroups 3 and 4 was highly significant. At the follow-upexamination after the second year, we found that

groups 3 and 4 developed a significantly larger numberof new carious lesions than 1 and 2.

These studies have confirmed that by frequentPMTC and oral hygiene instruction it is possible tosubstantially reduce caries development and almostentirely eliminate gingivitis. It must also be concludedthat in a preventive program based on meticulousplaque control, topical application of sodium mono-fluoride phosphate has only a marginal effect on cariesincrement.

In order to evaluate the separate preventive effectof PMTC on gingivitis and dental caries from oral hy-giene instructions, a "split-mouth" study was initiatedin 1976.~ One hundred four 13- to 14-year old-childrenwere randomly selected into two groups. Group 1 re-ceived oral hygiene instructions and random PMTCon the right or left side once every two weeks during a16 month experimental period (OHP + ). Untreatedside is (OHP-). Group 2 received only PMTC ran-domly on the right or the left side {P + ) or (P-) duringthe same period. Figure 6 shows the alterations of thePII and GI scores from baseline examination as a re-sult of the different procedures.

In group 1 PMTC and oral hygiene instructions(OHP ÷ ) reduced the PII from 78 to 22% and GI from49 to 14%. Only PMTC (P ÷ ) in group 2 gave a similarreduction of PII and GI. The single effect of PMTCon PII and GI was superior to oral hygiene instruc-tions in this study. But it must be observed that sig-nificant reductions of PII and GI were found on theuntreated side too.

These reductions can be explained partly by the

fact that children tried to clean the untreated sidethemselves at the same level as the treated side. Also,the total amount of the oral microflora is supposed tobe reduced as an effect of the frequent PMTC.

Figure 7 shows the total number of new interproxi-mal DF-s during the experimental period. Again thepreventive effect of PMTC is superior to oral hygieneinstructions.

After our original "Kalstad-study" in school chil-dren, other studies have been carried out in order toevaluate the effect of PMTC on gingivitis and dentalcaries. Table 1 is a summary of these studies,u78

Plaque-Control Program in Adults

In 1972 we performed an investigation to assess theefficiency of a maintenance care program in patientstreated for advanced periodontal disease, includingsurgery;3 The periodontal status of a group of patientswho were referred back to general practitioners formaintenance care at the end of treatment was alsoexamined. The population consist of 90 patients whowere referred for specialist treatment of advanced per-iodontal disease by general practitioners. Thepatients were first examined: they were each givencase presentation, instructed how to practice propertooth cleaning methods, their teeth were scaled andeventually the periodontal pockets were treated usingthe modified Widman technique.

During the first two months following surgery, thepatients were recalled once every two weeks forPMTC. Two months after the end of surgical treat-ment, the patients were re-examined to provide base-

%1st year_

50-

30-

10-0

10-

2 nd ye

%

Group 1 2 3HF PF

PF P OHF

Figure 6. Alterations of the P11 and GI scores from baseline exam-ination as a result of different procedures.

4P

OH

[::]- Pl %~l=Gl%

H = 0,5 %hibitangel

F = monofluor-phosphate

P = professionaltoothcleaning

OH = oral hygienetraining

PEDIATRIC DENTISTRY 109Volume 3, Special Issue

line data. Then, every third patient was sent back tothe referring dentist for maintenance care. Two out ofevery three patients were maintained at our clinic in acarefully designed and controlled maintenance careprogram. This program involved recalls once everytwo to three months and included instruction andpractice in oral hygiene, meticuluous scaling, andPMTC. The patients were re-examined three and sixyears after the baseline examination.

The results demonstrated that in patients sufferingfrom destructive periodontitis, a treatment programinvolving oral hygiene instruction, scaling, root plan-ing, PMTC and modified Widman flap proceduresestablished clinically healthy gingiva and shallowpockets.

Patients who were placed on a carefully designedrecall program over a six-year period were able tomaintain excellent oral hygiene standards and unal-tered attachment levels. In contrast, patients notmaintained in a supervised, active treatment programshowed obvious signs of recurrent periodontitis at thefollow-up examinations.

Therefore, in 1971-1972 an investigation was initi-ated in the city of Karlstad to determine if the occur-rence of caries and the progression of periodontitiscould be prevented in adults and maintained at a highlevel of oral hygiene by regularly repeated oral hy-giene instructions, scaling and PMTC.79,~ An attemptwas also made to study the progression of dental dis-eases in individuals who received no special oralhygiene instruction but regularly received dental careof a traditional type.

Table 1. The effects of cfinica~ tria~s based on professlona~ mechanica~

studies" are not included).

GINGIVITIS AND PLAQUE

PL%

OHP+ OHP-p+ P-

100- GI %

Figure 7. Total number of new interproximal DF-s during theexperimental period.

tooth cleaning (PMTC) on gingivitis and dental caries (The "Karlstad-

Annual caries CariesFrequency of increment reduc- Reduced PII

cleaning Test Control tion Test Control

Reduced Lengthgingivitis Age of Ref

Test Control group trial Author(s) year number

Fortnightly 0.18 1.75 90% 75% No diff No ex No exFortnightly *0.94 3.40 73% No ex No ex No ex No exFortnightly *2.80 7.30 61% Sign. -- 60% --

red.Monthly 3.40 4.50 24% No ex No ex 38% --Monthly * 1.21 3.40 64% No ex No ex No ex No exMonthly 0.81 1.78 54% 75% -- 75% --Every 3rd month 1.20 2.97 60% No ex No exEvery 6th month -- -- 0Weekly No ex No ex No ex No ex No ex 75% --

Balancing the effect of tluorideFortnightly 0.14 0.40 64% 75% 10%Fortnightly 0.43 1.42 70% 60% 8%Every 3rd week 1.40 2.09 33% 40% 15%Every 3rd week 2.10 4.17 51% 73% --Daily flossing 0.15 0.33 55% No ex No ex

70% --70% 10%45% 20%59% --

No ex No ex

13-16 2 yrs Karlsson & Larsson/76 649-12 2 yrs Klock & Krasse/78 65

13-17 2 yrs BjCrn et al./ 66

10-12 1 yr Badersten et al./75 679-12 2 yrs Klock & Krasse/78 657 4 yrs Bellini eta]./ 68,69

17-19 3 yrs Malmberg/76 7010-12 2 yrs Ripa et al./76 7120 4 wks Talbott et al./77 72

7-14 2 yrs Kjaerheim et al./79 737 1 yr Poulsen et al./76 748 1 yr Agerbaek et al./77 757-16 3 yrs Hamp et al./78 766 20 mths Wright et al./77/79 77,78

* Selected "risk children."

PLAQUE-CONTROL110

Axelsson

Two groups of individuals from one geographic sitewere recruited in 1971-72 for the trial; 375 were as-signed to a test and 180 to a control group. A baselineexamination revealed that the socio-economic status,the oral hygiene status, the incidence of gingivitis andthe caries experience were similar among the test andcontrol participants prior to the start of the study.During the subsequent six-year period, the control pa-tients were seen regularly once a year and given tradi-tional dental care. The test group participants, on theother hand, were seen once every two months duringthe first two years and once every three months dur-ing the following four years of the trial. They weretaught a proper oral hygiene technique on an individ-ual basis, and given a careful dental prophylaxisincluding scaling, root planing and PMTC. Each pro-phylactic session was handled by a dental hygienist.

A re-examination was carried out near the end ofthe third and sixth year of the trial. 79,~ The resultsclearly showed that it is possible, by regularly re-peated tooth cleaning instruction and prophylaxis, tostimulate adults to adopt proper oral hygiene habits.The findings also demonstrated that persons who uti-lized proper oral hygiene techniques during a six-yearperiod had negligible signs of gingivitis, suffered noloss of periodontal tissue attachment, and developedpractically no new carious lesions. The control pa-tients who received merely symptomatic treatmentduring the same period, suffered from gingivitis, lostperiodontal tissue support, and developed several newand recurrent carious lesions. These results indicatethat traditional dental treatment is a highly ineffec-tive means of curing caries and periodontal disease.

After six years with four prophylaxis visits per yearfor the test groups, the number of new DF-s per indi-

¯ vidual per six years was only 0.2 compared to 14 DF-sper individual per six years in the control group. Inaddition, the average cost for dental care in the con-trol groups was around 400 Sw crowns {100 dollars)per-person-per-year, compared to 150-200 Sw crowns(50 dollars) per-person-per-year in the test groups.

After the six-year re-examination/9.~ the intervalsbetween the prophylaxis visits were increased in thetest groups on an individual basis because the selec-tive oral hygiene habits had been successfully estab-lished. Now most of the patients visit the dental hy-gienist only once a year and still have the same highlevel of oral health. Out of 375 individuals in the testgroups at baseline, around 300 individuals still remainin the trial.

ConclusionThe present study clearly demonstrates that proper

plaque control measures are also highly effective inthe prevention of caries as well as periodontitis. It is

important, however, to realize that toothbrushing isnot synonymous with proper tooth cleaning. A properplaque control program includes measures whichremove plaque on all tooth surfaces.

Dr. Axelsson is chairman, Department of Preventive Dentistryand Dental Hygiene School, Public Dental Health, Alvgatan 47, 65230 KARLSTAD, Sweden. Requests for reprints should be sent tohim at that address.

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PEDIATRIC DENTISTRY111

Volume 3, Special Issue

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1 12 PLAQUE-CONTROLAxelsson

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PEDIATRIC DENTISTRY i13Volume 3, Special Issue