Advances in Dental Research

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The Effect of a New Oral Hygiene Training Program On Approximal Caries in 12-15-Year-Old Brazilian Children: Results After Three Years P. Axelsson, Y.A.P. Buischi, M.F.Z. Barbosa, R. Karlsson and M.C.B. Prado ADR 1994 8: 278 DOI: 10.1177/08959374940080022201 The online version of this article can be found at: http://adr.sagepub.com/content/8/2/278

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THE EFFECT OF ANEW ORAL HYGIENE TRAINING PROGRAM ON APPROXIMAL CARIES IN 12-15-YEAR-OLD BRAZILIAN CHILDREN! RESULTS AFTER THREE YEARS P . AXELSSON1 Y.A.P. BUISCHI2 M.F.Z. BARBOSA2 R. KARLSSON1 2 M.C.B. PRADO

T

Department of Preventive Dentistry Public Dental Health Service Alvgatan 47 S-652 30 Karlstad, Sweden 2 Clinica Buischi Rua Cristiano Viana, 72 CEP 05411-Pinheiros Sao Paulo, SP, Brazil Adv Dent Res 8(2): 278-284, July, 1994

Abstract—This study evaluated the effects of a new oral hygiene training program on approximal caries in a population of 12-13-year-old Brazilian schoolchildren with a wellestablished habit of daily toothbrushing with a F dentifrice. Two hundred twenty-two children were randomly allocated into two test groups (I and II) and one control group (III). Group I subjects were trained to establish needs-related oral hygiene habits based on self-diagnosis and a new behavioral principle, the 'linking method', for establishment of habits. The first three visits (20 minutes each) were scheduled at twoday intervals. They were recalled for a monthly check-up during the first 4 months, and then every 3 months for reevaluation of the results based on self-diagnosis. Group II subjects were recalled at the same intervals for detailed oral hygiene instruction on how to clean every tooth surface using dental tape, toothbrush, and fluoride dentifrice. Group I developed significantly fewer (p < 0.001) new approximal manifest (dentin) caries lesions than groups II and III. The mean values (SEM) were 2.3(0.29),4.7(0.59),and5.3(0.68),respectively.Theconclusions from our study are: • In a toothbrushing population using fluoride dentifrices and fluoridated drinking water, the oral hygiene training program with behavioral modification significantly reducedcaries incidence on approximal surfaces. • Frequentrepetition of training in meticulous oral hygiene is almost redundant. This manuscript was presented at a Symposium entitled "Mechanisms and Agents in Preventive Dentistry ", held October 28-November 1, 1992, in Chester, England, under the auspices of the Council of Europe Research Group on Surface and Colloid Phenomena.

oothbrushing is the most widespread mechanical means of personal plaque control, and almost 100% of Scandinavian schoolchildren brush their teeth with a fluoride dentifrice once or twice a day. However, fewer than 1% apply a fluoride dentifrice to flat dental tape to clean the approximal surfaces of the molars and premolars. Using the tape by hand or in a special holder, one can remove plaque 2 mm subgingivally on the approximal surfaces of the molars. The caries-preventive effect of daily toothbrushing has been questioned. In the hundreds of studies based on supervised toothbrushing, the control groups have been comprised of subjects with an established habit of daily toothbrushing, sometimes more frequent and efficient than the test groups, i.e., they were not true control groups (for review, see Bellini et al., 1981). The subjects in most such studies have been teenagers, in whom most occlusal surfaces of the molars are already filled. Frequency of brushing has been controlled, but not the quality, e.g., by plaque disclosure. In this age group, the caries incidence is greatest on the approximal surfaces of the molars and premolars, which are inaccessible to a toothbrush. The caries-preventive effect of such supervised toothbrushing, presented as an average value for all tooth surfaces in the dentition, is low (Braun and Ericsson, 1977). Experiments evaluating the effect on buccal surfaces alone, with quality control, have shown substantial reductions in caries (Ainamo, 1971). In the plaque formation rate index (PFRI) study in 14-yearold schoolchildren, the pattern of free plaque re-accumulation within 24 h after Professional Mechanical Tooth-cleaning (PMTC) reflected the caries prediction sites for this age group in a population with well-established daily toothbrushing habits (Axelsson, 1991). For successful establishment of needs-related tooth-cleaning habits, the patient must be well-motivated, -informed, and instructed. Motivation is defined as readiness to act, or the driving force behind our actions. The most enduring motivating factor is greater responsibility. Our actions are governed by our perceived needs. Therefore, self-care should be based on self-diagnosis. A fundamental principle of prevention is that the effect is greatest where the risk of disease is greatest. Patients are most likely to see positive results from their oral hygiene efforts if they initially concentrate on 'key-risk teeth' and 'key-risk surfaces'. In behavioral science, the 'linking method' (Weinstein and Getz, 1978) recommends that new routines to be introduced should be closely linked to already-established habits. The

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TABLE 1 CARIES PREVALENCE AT BASELINE [Mean (SEM)] Variable

DMFS Manifest caries Secondary caries Incipient caries lesions

AS AM AS AM AS AM AS AM

Group I (n = 79)

Group II (n = 72)

Group III (n = 71)

P+

2.7 2.1 1.0 0.9 0.6 0.6 5.6 5.5

2.8 2.3 0.9 0.8 0.5 0.5 6.7 5.9

3.6 2.9 1.5 1.2 0.9 0.9 7.6 6.5

NS NS NS NS NS NS < 0.05* NS

(0.34) (0.28) (0.17) (0.17) (0.12) (0.11) (0.49) (0.47)

(0.45) (0.34) (0.19) (0.17) (0.15) (0.12) (0.59) (0.53)

(0.49) (0.37) (0.24) (0.21) (0.19) (0.16) (0.67) (0.60)

*Group III * Group I. 'Probability (ANOVA test). AS = Approximal surfaces. AM = Approximal surfaces of premolars and molars.

new habit should always be carried out immediately prior to the established habit, since the risk of neglecting the latter is minimal. For example, if the patient's oral hygiene habits are irregular, an interview will reveal other daily routines which coincide with times most appropriate for oral hygiene. The patient may be in the habit of taking a shower every morning and watching the news on TV every evening. According to the 'linking method', oral hygiene should be scheduled immediately prior to the morning shower and the evening news. Similarly, needs-related oral hygiene in children and young adults should begin with the application of F dentifrice interproximally in the molars and premolars. These surfaces are then meticulously cleaned with dental tape. Since the use of toothbrush and toothpaste on the buccal surfaces is an established, non-needs-related habit, there is no risk involved in leaving this until last. The toothbrush should first be applied to the lingual of the mandibular posterior teeth, where most people do not use the toothbrush efficiently. With needsrelated tooth-cleaning, following the 'linking method', the order is thus the reverse of the traditional routine recommended to patients. Early establishment of the habit of interdental tooth-cleaning with dental tape and toothpaste should prevent approximal caries and loss of interproximal periodontal support (Wright et ai, 1979; Finkelstein and Grossman, 1979); the habit will be life-long. Needs-related tooth-cleaning, including approximal cleaning, is probably practiced by less than 15% of the population in industrialized countries today (Hakansson, 1978; Riise etaU 1991). The effect on the future demand for dental personnel would be profound if, through the 'linking method', needs-related tooth-cleaning habits were established in all patients. According to the WHO data bank, caries prevalence is very high among children and young adults in Brazil, e.g., the average DMFT for 12-year-olds is > 6.5 DMFT. The mean DMFS is about 25 in 12-year-olds in Sao Paulo (Buischi etal., 1989). Among those children who possess a toothbrush, most

are self-taught brushers, and only a few receive regular oral hygiene instruction by the family dentist. The self-taught begin by scrubbing mainly the labial surfaces of the anterior teeth and seldom proceed to the lingual surfaces. Interproximal cleaning is non-existent. The controversial role of conventional self-performed oral hygiene, in caries prevention is probably related to the following: (1) The level of motivation of oral hygiene in a number of tooth-cleaning programs is questionable. More efficient motivation, targeting the personal needs of the patient, may improve the quality of plaque control. This may be accomplished by the active involvement of the patient in the program, through self-diagnosis of dental needs and conditions and by the dentist encouraging the patient to make his or her own suggestions about cleaning priorities. (2) Conventional toothbrushing does not achieve efficient plaque control in caries key-risk sites. The present investigation evaluated the effects of a needsrelated oral hygiene training program on approximal caries in 12-year-old schoolchildren.

MATERIALS AND METHODS The 'Sao Paulo study' was carried out during 1984-1987. The participants were 222 children aged 12-13 years (118 girls and 104 boys) in sixth grade at a private school in Sao Paulo, whose parents had given written consent. All had well-established oral hygiene habits, brushing daily with a fluoride dentifrice, and had had fluoridated drinking water since December, 1985. The study conditions were explained to the children and their parents, and—after parental consent had been granted—to the school personnel. The participants' oral health status was assessed clinically and radiographically at baseline and annually during the 3-year experimental period. A written communication was always sent to the parents when a condition which required attention was detected. After baseline, the subjects were randomly assigned to two test groups (79 in I and 72 in II) and one control group [III (71)]. During the experimental period,


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TABLE 2 CARIES PREVALENCE AT THE FINAL EXAMINATION [Mean (SEM)] Variable

DMFS Manifest caries Secondary caries Incipient caries lesions

AS AM AS AM AS AM AS AM

Group I (n = 68)

Group II (n = 59)

Group III (n = 60)

5.1 4.0 1.9 1.6 0.9 0.7 9.1 7.8

7.6 6.2 3.5 3.1 1.5 1.1 10.2 8.0

8.5 (0.84) 7.5 (0.70) 4.2 (0.52) 3.8 (0.47) 1.3 (0.25) 1.2 (0.24) 10.3 (0.69) 8.5 (0.50)

(0.52) (0.43) (0.25) (0.24) (0.19) (0.17) (0.60) (0.53)

(0.83) (0.65) (0.48) (0.44) (0.33) (0.24) (0.65) (0.54)

40% = very high.

of children with low caries incidence (0-2 DFS) is found in Group I.

Statistical Analysis

DISCUSSION The caries reduction on all approximal surfaces in Group I was 50% of that in Group II and 57% that of Group III. In molars and premolars, the caries reduction in Group I was 54% of that of Group II and 63% that of Group III. These data are similar to the Dorchester dental flossing study by Wright et al. (1979). The Dorchester study was carried out in a fluoride-deficient town. Two test groups of 6-year-old schoolchildren participated in a 20-month longitudinal split-mouth study. A dental assistant used dental floss to clean all the approximal surfaces of the test side meticulously once a day in every child, i.e., daily semiprofessional approximal toothcleaning. The caries reductions were 55% and 52% in the two test groups compared with the untreated contralateral side. Such a significant caries reduction in test group I compared with groups II and III was therefore unexpected. In the present study, all participants used F dentifrice, and during the two last years had fluoridated drinking water. Today, there is overwhelming evidence that water fluoridation has mainly a post-eruptive caries-preventive effect (for review, see Ekstrand et ai, 1988). In addition, test group II received detailed repeated oral hygiene instruction at the same intervals as the test group I recalls for self-evaluation of their needs-related oral hygiene program. There was no significant difference in approximal caries incidence between test group II and the control group (III), indicating that without self-diagnosis and quality control, approximal oral hygiene instruction is ineffective in a population with a well-established habit of daily toothbrushing with F dentifrice. Without quality control, even daily supervised flossing may not result in further caries reduction. In a two-year, split-mouth study, 12-13-year-old schoolchildren were supervised daily in pulling waxed floss up and down once only through the approximal contacts (Granath et al., 1979). Passing waxed

One-way analysis of variance (ANOVA) was used to test the significance of differences among groups. When the ANOVA rejected the multi-sample hypothesis of equal means, multiple comparison was performed with Student-Newman-Keuls' multiple-range test. Statistical testing was performed twotailed and at the 0.05 significance level.

RESULTS Baseline data on the different caries scores are presented in Table 1. There were no statistically significant differences among the groups, except for a higher prevalence of incipient caries lesions in Group III than in Group I. Table 2 presents the scores for all three groups at the end of the experiment. There are statistically significant differences among the groups for DMFS and manifest caries, both for all approximal surfaces and for molars and premolars. Group I differs significantly from groups II and III, with no differences in caries incidence between the latter two groups. Consistent with these findings are the results of caries progression in terms of mean new manifest DFS during the study period. Group I differs significantly (p < 0.001) from groups II and III: Fig. 1 shows that the mean new approximal DFS for Group I is around 50% less than that for the other two groups. The corresponding values for molars and premolars shown in Fig. 2 are similar. The frequency distributions of new DFS in all approximal surfaces are shown in Fig. 3. The most significant difference among groups I, II, and III is found in the upper tail, i.e., only 30.9% of children from Group I had 8 new DFS or more, compared with 49.3% and 40.2% in groups II and III, respectively. Fig. 4 depicts the frequency distribution of new DFS in molars and premolars. The frequency of children developing 8 or more lesions in Group I is roughly 50% of those in groups II and III, and a considerably higher percentage


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floss through the contact points will not remove approximal plaque, so it is not surprising that there was no caries-preventive effect on the test side compared with the contralateral control side. On the other hand, proper daily use of dental floss and toothbrush resulted in 77-83% plaque-free mesiobuccal, mesiolingual, distobuccal, and distolingual surfaces, compared with only 26-43% with toothbrush alone (Reitman et al., 1980). In another study, children in grades 5-8 participated in a 3year longitudinal study of the effect on oral hygiene, gingival inflammation, and dental caries of removing dental plaque, through supervised daily flossing and toothbrushing in school. A fluoride-free dentifrice was used. The Controls received no instruction in plaque-removal procedures, nor did they engage in plaque-removal activities at school. The test group developed significantly (22%) fewer new approximal caries lesions than the control group. The plaque and gingivitis reductions of about 20% and 30%, respectively, were also significant (Suomi etaU 1980). Other authors have shown that established interdental selfcare habits significantly reduce approximal dental caries. In a 2year longitudinal study, one of the test groups was recalled with needs-related intervals once every 2-4 weeks for instruction on how to use dental floss daily. The test group developed, on average, only two new approximal DFS per individual over two years. But the children who, according to interviews with the parents, established a habit of using dental floss once a day or at least every second day did not develop any new approximal DFS during the 2-year period. The control groups, maintained in a preventive program without needs-related intervals, developed more than 4 new approximal DFS (Gisselson et al., 1983). Plaque control is directed toward caries etiology, i.e., to prevent the development of new caries lesions and progression of incipient caries (Axelsson et al., 1993). The most important caries-preventive effect of topical fluorides is the active role in remineralization of incipient caries (for review, see Ekstrand et al., 1988). Dijkman et al. (1990) conducted an experimental crossover study of the effects of different toothbrushing routines on the depth of experimentally induced enamel lesions, 100 Jim deep, on specimens of tooth enamel worn in situ for 3 months. During the first (control) period, the subjects did not brush at all: Fifty percent of the lesions progressed. During the next period, the subjects brushed daily with a placebo dentifrice: No lesions progressed. During the final period, the subjects brushed daily with a F dentifrice: Forty percent of the experimental lesions decreased in depth, i.e., an additional 40% caries reduction and a total caries reduction of 90%. The authors concluded that the remineralizing efficacy of F dentifrice is due to the cleaning effect of the brushing by the dentifrice (presumably on the pellicle), as well as to the fluoride effect on mineral nucleation and growth. In the present study, all participants had frequent daily fluoride exposure from F dentifrice and fluoridated drinking water. Therefore, at least 80% of the caries reduction in test group I compared with the control group should be attributed

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to the interproximal toothcleaning by use of dental tape and less than 20% to the use of F dentifrice interdentally. More than 92% of the new DFS in the control group developed on the approximal surfaces of the molars and premolars (4.9 out of 5.3). In a toothbrushing population, there is a strong correlation between approximal caries development and surface colonization by S. mutans (Axelsson et al., 1987). In 12-13-year-olds, the highest approximal S. mutans scores are localized to the molars (Kristoffersson et al., 1984). The same surfaces have the highest PFRI scores (Axelsson, 1991). In telemetric tests of plaque pH in vivo (Imfeld, 1978), rinsing with 10% sucrose solution caused a dramatic pH drop, to below 4, in 3-day old plaque; such plaque is typical for the molars and premolars in a toothbrushing population. In children 13 years of age, these are caries predilection sites. Similar results have been shown by Kleinberg (1985) and Firestone and Miihlemann (1985). The authors concluded: 'removing plaque from interdental surfaces significantly reduced the exposure of the surfaces to plaque acids following sucrose rinse. This further supports mechanical removal of plaque from interdental surfaces as a means of reducing dental caries.' The most significant caries reduction was achieved in the molars and premolars in test group I, strongly motivated in interproximal plaque removal with dental tape compared with the toothbrushing control group (Figs. 2 and 4). Motivation, information, and instruction together are the pre-conditions, but do not guarantee establishment of needsrelated oral hygiene habits. A "motivated" individual is 'willing and prepared to act'. The outstanding, most long-lasting motivational factor is responsibility. In test group I, the children felt responsible for their own oral health, because they participated in self-diagnosis and self-evaluation at the recall visits. This was confirmed by questionnaires and interviews after the final examination. These basic principles for motivation, in combination with the 'linking method' for establishment of needs-related habits, explain why test group I developed significantly fewer new approximal DFS compared not only with the control group, but also with test group II. However, for cost-effectiveness in large-scale applications, the intervals between the recall visits for selfevaluation will be extended as soon as the needs-related oral hygiene habits are established. Test group II was recalled as frequently as test group I, but there was no significant difference in approximal caries incidence compared with the control group, i.e., repeated detailed information and instruction for establishment of needs-related self-care habits are ineffective in the absence of motivation based on self-diagnosis and behavioral principles. ACKNOWLEDGMENTS

The cooperation of Johnson & Johnson, Equipo Center Laboratorios Anakol, and Colgate-Palmolive (Brazil) is deeply appreciated. This study was partly supported by a grant from CNPq (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico) Brazil. We are also greatly indebted to Antoinette Mclntyre, for ready cooperation and fluent typing of the manuscript.


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REFERENCES Ainamo J (1970). Concomitant periodontal disease and dental caries in young males. Soum Hammaslddk Toim 66:301364. Axelsson P, Kristoffersson K, Karlsson R, Bratthall D (1987). A 30-month longitudinal study of the effects of some oral hygiene measures on Streptococcus mutans and approximal dental caries. J Dent Res 66:761-765. Axelsson P (1991). A four-point scale for selection of caries risk patients, based on salivary S. mutans levels and plaque formation rate index. In: Johnson NW, editor. Risk markers for oral diseases, Vol I. Dental caries. Cambridge: Cambridge University Press, 158-170. Axelsson P, Paulander J, Svardstrom G, Tollskog G, Nordensten S (1993). Integrated caries prevention: The effect of a needs-related preventive program on dental caries in children—County of Varmland, Sweden—Results after 12 years. Caries Res 27(Suppl l):83-94. Axelsson P (1993). New ideas and advancing technology in prevention and nonsurgical treatment of periodontal disease. IntDent J 43:223-238. Bellini HT, Arnberg P, von der Fehr FR (1981). Oral hygiene and caries. A review. Acta Odontol Scand 39:257-265. Braun K, Ericsson Y (1977). Munhygien och karies. Tandldk tidn 69:663. Buischi YAP, Axelsson P, Zulske Barbosa M, Mayer M, Carmen M, de Oliviera L (1989). Salivary S. mutans and caries prevalence in Brazilian schoolchildren. Community Dent Oral Epidemiol 17:20-30. Dijkman A, Huizinga E, Kuben J, Arends J (1990). Remineralization of human enamel in situ after 3 months: The effects of not brushing versus the effect of a F-dentifrice and a F-free dentifrice. Caries Res 24:263-266. Ekstrand J, Fejerskov O, Silverstone LM (1988). Fluoride in dentistry. Copenhagen (Denmark): Munksgaard. Finkelstein P, Grossman E (1979). The effectiveness of dental floss in reducing gingival inflammation. J Dent Res 58:10341039. Firestone AR, Muhlemann HR (1985). In vivo pH of plaquecovered and plaque-free interdental surfaces in humans following a sucrose rinse. Clin Prev Dent 7:25-26.

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Gisselson H, Bjorn AL, Birkhed D (1983). Immediate and prolonged effect of individual preventive measures in caries and gingivitis susceptible children. Swed Dent 77:13-21. Granath LE, Martinsson T, Matsson L, Nilsson G, Schroeder U (1979). Intraindividual effect of daily supervised flossing on caries in schoolchildren. Community Dent Oral Epidemiol 7:147-150. Grondahl HG, Hollender L, Malmcrona E, Sundqvist B (1977). Dental caries and restorations in teenagers. I. Index and score system for radiographic studies of proximal surfaces. Swed Dent J 1:45-50. Guilford JP (1965). Reliability of measurements. In: Fundamental statistics in psychology and education. 4th ed. New York (NY): McGraw-Hill, 438-469. Hakansson J (1978). Dental care habits, attitudes towards dental health and dental status among 20-60-year-old individuals in Sweden (thesis). University of Lund. Malmo (Sweden): Bokforlaget Dialog. Imfeld T (1978). In vivo assessment of plaque acid production. A long-term retrospective study. In: Guggenheim B, editor. Proceedings, ERGOB Conference on Health and Sugar Substitutes. Basel (Switzerland): Karger, 218-223. Kleinberg I (1985). Oral effects of sugars and sweeteners. Int Dent J 35:180-189. Kristoffersson K, Axelsson P, Bratthall D (1984). The effect of a professional tooth-cleaning program on interdentally localized Streptococcus mutans. Caries Res 18:385-390. Reitman WR, Whitely RT, Robertson PB (1980). Proximal surface cleaning by dental floss. Clin Prev Dent 2:7-8. Riise J, Haugejorden O, Wold B, Aaro LE (1991). Distribution of dental health behaviours in Nordic schoolchildren. Community Dent Oral Epidemiol 19:9-13. Suomi JD, Peterson JK, Matthews BL, Voglesong RH, Lyman B A (1980). Effects of supervised daily dental plaque removal by children after 3 years. Community Dent Oral Epidemiol 8:171-176. Weinstein P, Getz T (1978). Changing human behavior— strategies for preventive dentistry. Chicago (IL): Science Research Associates (SRA) Inc., 39-40. Wright GZ, Banting DW, Feasby WH (1979). The Dorchester dental flossing study: final report. Clin Prev Dent 1:23-26.
