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Individual Versus Group Oral Hygiene for Adults
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Dirk Ziebolza/Alexander Herzb/Edgar Brunnerc/Else Horneckera/ Rainer F. Mausberga
Purpose: The objective of this study was to assess the practicability and effectiveness of group oral hygiene instruction for adults in comparison with individual oral hygiene instruction. Materials and Methods: A total of 104 male subjects aged 18 to 54 (mean age: 29.7) years were randomly assigned to one of four groups: group A was given individual oral hygiene instruction; group B was given group oral hygiene instruction; group C was given a combination of individual and group oral hygiene instructions; and group D received no oral hygiene instruction (the control group). The success of each form of instruction was evaluated on the basis of four parameters: (1) the Quigley–Hein plaque index (QHI), (2) the approximal plaque index (API), (3) a modified sulcus bleeding index (SBI) and (4) the community periodontal index of treatment needs (CPITN). All participants had professional tooth cleaning at the end of the baseline examination. The final examinations were conducted 13 weeks later. Results: All subjects showed a poor oral health status at the beginning of the study, and the mean QHI score was 2.2. In addition, 92% of all subjects had an API score of more than 70%. Moderate-to-severe gingival inflammation (modified SBI) was observed in 67.3% of the subjects. CPITN scores of 2 or 3 were calculated for 82% of all sextants. At the end of the study, all groups showed a significant improvement in their oral health status and periodontal parameters (P < 0.0001). The majority of the subjects achieved an API score between 25% and 70%, and they had a mean QHI score of 1.2. A CPITN score of 0 or 1 was recorded for most sextants (62%). There was no significant difference between the various groups. Conclusions: This study demonstrated that group oral hygiene instruction and conventional individual instruction have similar beneficial effects in adults. Key words: adults, group prophylaxis, individual prophylaxis, oral hygiene instruction Oral Health Prev Dent 2009; 7: 93–99.
Submitted for publication: 19.02.2008; accepted for publication: 22.02.2008.
ental caries and periodontal disease are the main causes of tooth loss and are among the most prevalent health problems in the world. Their
D a
Department of Operative Dentistry, Preventive Dentistry and Periodontology, University of Goettingen, Goettingen, Germany.
b
Private Dental Practice, Vechta, Germany.
c
Department of Medical Statistics, University of Goettingen, Goettingen, Germany.
Correspondence: Dr Dirk Ziebolz, Department of Operative Dentistry, Preventive Dentistry and Periodontology, Robert-Koch-Strasse 40, D-37075 Goettingen, Germany. Tel: +49 (0) 551 39 8368. Fax: +49 (0) 551 39 2037. Email:
[email protected]
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prevalence was reported to be more than 95% in the developed countries (World Health Organization [WHO], 1997; Petersen, 2003). After 35 years of age, tooth loss occurs due to diseases of the periodontium rather than due to damage to the hard tooth substance or consequences of this damage (Micheelis and Schiffner, 1999, 2006). Although a marked decline in dental caries as a result of preventive interventions has been observed in recent years, the incidence of periodontal disease remains high (Newbrun, 1987; Goebel and Gaengler, 1992; Kuenzel, 1997; Micheelis and Schiffner, 1999, 2006). The prevalence of gingivitis, for example, has been reported to be between 60% and 100% in Germany (Micheelis and Schiffner, 1999, 2006). 93
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A total of 104 male patients aged 18 to 54 (mean age: 29.7) years volunteered to participate in this study. All participants were members of the German
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In contrast, a decrease in plaque-associated gingivitis by as much as 80% has been reported in Switzerland during the past 30 years. Saxer et al (2005) believed that this is due to the introduction of intensive preventive measures. Microbial colonisation on tooth surfaces (i.e. the formation of an oral biofilm) is the primary aetiological factor involved in caries and periodontitis, although systemic, social and environmental factors can also play a role. Many epidemiological studies have proved that there is a correlation between the two diseases and poor oral health status (Axelsson and Lindhe, 1981; Guelzow, 1995). The focus of the services provided by the clinicians has increasingly shifted from treating the manifested lesions (curative dentistry) to preventing the development or progression of the diseases such as caries, gingivitis and periodontitis (preventive dentistry). The current knowledge of the aetiology of caries and inflammatory periodontal diseases enables clinicians to address both types of diseases effectively by instituting preventive measures. These efforts require close cooperation between clinicians/prophylaxis assistants and patients. Experience has shown that regular professional tooth cleaning is of paramount importance in this context (Axelsson and Lindhe, 1978; Axelsson, 1990; Axelsson et al, 1991; Goebel and Gaengler, 1992; Klimm et al, 1994; Bastendorf, 2005). Prophylactic care can be provided at an individual, collective or small-group level (Zimmer et al, 1993). An individual oral hygiene programme in combination with professional tooth cleaning was proved to be the most effective approach for adult patients (Weinstein et al, 1989). In contrast, group oral hygiene instruction is most commonly given for school and kindergarten children, and it is usually not used in dental practices (Axelsson, 1990; Buischi et al, 1994; Pieper, 1998; Ramseier et al, 2007). The objective of this study was to assess the suitability of group oral hygiene instruction for adult patients in dental practice. For this purpose, the efficiency and the practicability of group oral hygiene instruction was compared with those of the conventional individual instruction.
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pyrig No Co t fo rP ub lica tio armed forces, and they received dental care in the n t same medical centre. Patients with dental essimplants e c e nstudy or removable dentures were excluded. This was approved by all institutions and bodies concerned and was found to be safe for the participants. Before the study commenced all the patients were asked to complete a questionnaire that was designed to assess their knowledge of oral hygiene. One point was awarded for each correct response, giving a possible range of scores from 0 to 30. The participants were randomly assigned to one of the following four groups. • Group A (n = 27): individual oral hygiene instruction (one session). • Group B (n = 25): group oral hygiene instruction (one session). • Group C (n = 26): a combination of individual and group oral hygiene instructions. • Group D (n = 26): no oral hygiene instruction (control group). The subjects were randomised according to their date and time of appointment (i.e. for sick calls). The first patient was assigned to group A, the second to group B and so on. The patients were allocated irrespective of their clinical condition. Table 1 presents the composition of the four groups with regard to age and rank.
Clinical examination and parameters Two clinicians were involved in this study. The first clinician performed the baseline examinations and provided the oral hygiene instruction, whereas the second clinician who was blinded to the patient groups conducted the final examinations. Both examiners were calibrated prior to the study. Table 2 gives an overview of the time course of the study. The dental examinations included the determination of the decayed, missing and filled teeth (DMFT, DT [decayed teeth], MT [missed teeth], FT [filled teeth], respectively) index and an evaluation of the following parameters. • Oral hygiene: After staining the teeth with Mira-2Tone disclosing solution (Hager & Werken GmbH, Duisburg, Germany; this solution highlights old plaque as blue and new plaque as red), the presence or the absence of dental plaque on smooth tooth surfaces (Quigley–Hein plaque index, QHI) (Quigley and Hein, 1962; Turesky et al, 1970) Oral Health & Preventive Dentistry
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27 25 26 26
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Table 1
pyrig No Co t fo r P et al Ziebolz ub lica tio Composition of the four groups with regard to age (range), mean age and rank n te e s s c en Number Age (range) Mean age Rank (number of subjects) (years)
19–52 19–54 18–54 18–54
28.1 31.4 29.5 29.7
Officer
Non-commissioned officer
8 8 8 5
6 3 3 8
Rank and file 13 14 15 13
Table 2 Study design Time course
Group A
Baseline examination and any necessary treatment (first clinician)
Calculation of QHI, API, modified SBI and CPITN scores. Professional tooth cleaning (debridement). Correction of overhanging restoration margins
Three days later (first clinician)
Individual oral hygiene instruction (45 min)
Ten days later (first clinician)
Final examination 13 weeks later (second clinician)
Group B
Group D
Individual oral hygiene instruction (45 min) Oral hygiene instruction for groups of five to eight patients (45 min)
Oral hygiene instruction to groups of five to eight patients (45 min)
Calculation of QHI, API, modified SBI and CPITN scores
and in interdental spaces (approximal plaque index, API) (Lange et al, 1977) was assessed. • Gingival inflammation: A gingival index (modified sulcus bleeding index, the modified SBI) to assess gingivitis (Lange, 1986) was used. • Periodontal treatment needs: The need for periodontal treatment was evaluated using a periodontal index (community periodontal index of treatment needs, CPITN) (Ainamo et al, 1982). Each tooth was examined at six definite points for obtaining the highest CPITN score for each sextant. All patients were informed of the test results, and they received professional tooth cleaning at the end of the baseline examination. In addition, overhanging restoration margins were corrected. The final examinations were conducted 13 weeks later and they included an evaluation of the abovementioned indices. Vol 7, No 1, 2009
Group C
Table 3 Oral hygiene instruction sessions identified in terms of content and structure Theoretical background:
Motivation: Practical support:
Relation between dental plaque and caries, and between dental plaque, and inflammation of the gums Purposes of oral hygiene measures and personal benefits Demonstration of a correct toothbrushing technique (modified Bass technique) Instruction on how to clean interdental spaces (dental floss and interdental brushes)
All oral hygiene instruction sessions were identical in terms of content and structure (Table 3). Instruction was provided in individual sessions for the members of groups A and C and in group sessions for the members of group C. Group B 95
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pyrig No Co t fo rP ub lica tio (N = 104), and then compared within and between t the various groups. ess c e n en
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Dental plaque on smooth tooth surfaces (QHI)
Fig 1 Box plots showing the distribution of the median QHI scores for groups A, B, C and D at the baseline (1) and the final examinations (2).
members received instruction exclusively in groups. Each group session involved five to eight patients and lasted for 45 min. Once the study was completed, the members of group D, too, received comprehensive oral hygiene instruction.
The mean QHI score for all participants was 2.2 at the baseline examination. The mean QHI score was 2.2 in groups A and D, 2.1 in group B and 2.3 in group C. At the time of the final examination, the mean QHI score was 1.2 for all patients. The mean scores were 1.1 for groups A and B, 1.2 for group C and 1.4 for group D. Figure 1 shows the median QHI scores for the different groups at the baseline and final examinations. The statistical analysis revealed that the QHI scores were significantly less at the final examination when compared with the baseline examination (P < 0.0001). There were no significant different changes between the various groups (P = 0.32).
Dental plaque in interdental spaces (API)
A P value of < 0.05 was considered statistically significant.
Most of the participants (92%; n = 96) had an API score more than 70% at the baseline examination. A total of 6% (n = 6) of the patients had an API score between 70% and 50%; one participant had a recorded score between 50% and 35% and one patient had a score between 35% and 25%. At the time of the final examination, all groups had lower API scores. A score of > 70% was recorded for 49% of the patients and a score of < 70% for 51% of the patients. Almost 10% of the participants were found to have a score between 50% and 35% and another 10% had an API score between 35% and 25%. A score of < 25% was recorded for one member of group C. Figure 2 shows the median API scores for the different groups at the baseline and the final examinations. The statistical analysis revealed that the API scores were significantly less at the final examination when compared with those at the baseline examination (P < 0.0001). The changes in the control group appeared to be less marked, whereas groups A, B and C showed similar changes in their API scores. There were no changes in the API scores (P = 0.79) between the various groups.
RESULTS
Gingival inflammation (modified SBI)
The changes that were noted in the results between the baseline and the final examinations are first presented in a descriptive manner for all participants
At the baseline examination, 19 participants had an SBI score of > 50%, and 51 patients had a score between 20% and 50%. An SBI score between 10%
Statistics The statistical analysis of the parameters (QHI, API, modified SBI and CPITN) was based on the four patient groups, two time points and the relationship between the various groups and time points. A non-parametric mixed model was used for analysing the data (Langer, 1998), and the results were adjusted for six covariates (age, questionnaire score, DMFT, DT, MT and FT). Two basic questions that are given below were addressed: 1. Does time have a significant effect? That is, are there differences in the results obtained at the baseline and at the final examinations for each parameter? 2. Is the interaction between group and time point significant? That is, are there different changes in the various groups for each parameter?
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and 20% was recorded for 25 subjects. Only 9 patients had a score of < 10%. At the time of the final examination, the score was more than 50% in 12 patients; between 50% and 20% in 40 patients, between 20% and 10% in 18 patients and less than 10% in 34 patients. Figure 3 shows the median modified SBI scores for the various groups at the baseline and at the final examinations. The statistical analysis revealed that the SBI scores were significantly less at the time of the final examination when compared with those at the baseline examination (P < 0.0001). The most noticeable improvement was found in group C, whereas groups A, B and D showed similar changes in their SBI scores. There were no significant changes in the SBI scores (P = 0.74) between the various groups.
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Fig 2 Box plots showing the distribution of the median API scores for groups A, B, C and D at the baseline (1) and at the final examinations (2).
Periodontal findings (CPITN) At the baseline examination, the majority of sextants were assigned a score of 2 (46%) or 3 (36%). A score of 1 was recorded for 16% of all sextants. At the time of the final examination, the percentage of sextants (62%) with a score of 0 or 1 had increased. The percentage of sextants that were assigned a score of 2 (24%) or 3 (13%) was considerably less than that at the time of the baseline examination. Table 4 gives an overview of the sextants with the different CPITN scores for the various groups at the time of the baseline and the final examinations. The statistical analysis showed that the CPITN scores were significantly lower at the time of the final examination when compared with those at the baseline examination (P < 0.0001). A comparison of the various groups revealed that most favourable results were achieved in group A. Similar results were found in groups C and D, whereas only minor improvements were found in group B. The statistical analysis of the CPITN scores revealed no significant changes between the various groups (P = 0.30).
DISCUSSION Dental prophylaxis is of paramount importance to oral health. Patient motivation, oral hygiene instruction, professional tooth cleaning and regular dental check-ups play a vital role in this context (Axelsson and Lindhe, 1981). Although individual instruction has been the method of choice for adults (Weinstein et al, 1989), group oral hygiene instruction has thus far been provided mainly for children (Pieper, 1998). Vol 7, No 1, 2009
Fig 3 Box plots showing the distribution of the median modified SBI scores for groups A, B, C and D at the baseline (1) and at the final examinations (2).
This study was conducted to assess, for the first time, the effectiveness and the practicability of group oral hygiene instruction for adults. For this purpose, the test subjects were assigned to one of four groups. The members of group A received individual instruction exclusively. The members of group B were given the same instructions, but rather than individually, in small groups of five to eight patients. The members of group C received initial individual oral instructions, and ten days later received oral instructions in small groups of five to eight patients. Group D (the control group) received no instructions. The authors’ evaluation was based on the four parameters including two oral hygiene indices, one gingival index and one periodontal index. All participants received professional tooth cleaning at the end of the baseline examination. As the assessment of the two oral hygiene indices required the staining of the teeth, it was safe to assume that any deposits of dental plaque or calculus had been removed by 97
C D
0
1
2
3
4
0 45 2 38 0 48 0 36
18 68 18 38 29 47 33 63
108 34 53 34 64 39 63 43
35 14 73 36 59 18 53 12
0 0 3 3 4 4 5 0
professional tooth cleaning. The oral health condition was thus largely comparable in all four groups. To the authors’ knowledge, there are no studies in the literature that are based on a similar approach. The focus of this discussion is, therefore, on a critical appraisal of the results obtained. At the beginning of the study, all four groups showed poor oral hygiene. Both the smooth surfaces of the teeth and the interdental spaces were found to be improperly cleaned. The patients also presented with a high level of gingival inflammation, and required periodontal treatment. These results were quantitatively similar to those obtained in earlier cross-sectional studies involving German military personnel (Brozio et al, 1982; Plewe et al, 1993; Mausberg et al, 2000). At the end of the study, the level of oral hygiene (QHI and API) and the periodontal condition (modified SBI and CPITN) had improved significantly in the three groups that received instruction. The same findings, however, were obtained for group D. There were no significant differences between the groups for any of the parameters investigated. In the literature, many studies have shown that the individual prophylaxis effectively improved the level of oral health and the periodontal condition in adults (Mausberg et al, 1987; Axelsson et al, 1991; Klimek et al, 1993; Zimmer et al, 1993). This study suggests that similar results can be achieved when oral health instruction is provided to adults exclusively in groups. A combination of individual and group instructions in which the patients received the same instruction twice did not lead to further improvement. It is particularly noteworthy that the control group showed a significant improvement in all results at 98
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Baseline examination Final examination Baseline examination Final examination Baseline examination Final examination Baseline examination Final examination
CPITN score (number of sextants)
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Table 4 Number of sextants with various CPITN scores for groups A, B, C and D at the baseline and at the final examinations
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pyrig No Co t fo rP ub lica tio the time of the final examination and that this n t improvement was of the same order ofe smagnitude e s c n as that noted for the other groups. eSeveral explanations are possible for this observation. The simple awareness of their role in a study may have been a reason for the control group members to pay greater attention to their dental health. Likewise, it is possible that these patients may have improved their oral hygiene habits in the knowledge that they would have a further appointment with a clinician (final examination). Glavind (1977) also reported this effect, and Lie and Mellingen (1988) observed a positive change in the oral hygiene habits of patients who attended regular appointments for calculus removal (Glavind, 1977; Lie and Mellingen, 1988). In addition, the entire setting of the study may have played a role. As all of the patients received dental care in the same medical centre, they might have discussed the study among themselves, and this may have been a motivation for the control group members to improve their oral hygiene habits. A similar effect was also reported by Albandar et al (1994). The effectiveness of individual prophylaxis has been clearly demonstrated in classical longterm studies (Axelsson and Lindhe, 1978, 1981; Morrison et al, 1982; Ramfjord et al, 1982; Zimmer et al, 1993). The results of this study show that group oral hygiene instruction, too, is effective and practical, and the group instruction that is individually tailored to the patient’s needs and provided in addition to the dental care presents an efficient prophylaxis model for adult patients. It should be noted that group oral hygiene instruction for adults offers economic advantages over individual instruction (in terms of patients per time unit) as more patients can be advised on how to maintain good oral hygiene in one session. It is implicit that individual care continues to play a key role in establishing a good and trusting relationship between a clinician and a patient. An important factor in this context is professional tooth cleaning that is provided at an individual level, and it is an imperative component of preventive dental care.
CONCLUSIONS This study shows that good results can also be achieved by providing group oral hygiene instruction for adults. Depending on a clinician’s philosophy, personnel resources and other factors, group instruction may be a useful approach for maintaining or improving the oral health of adult patients. Oral Health & Preventive Dentistry
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1. Ainamo J, Barmes D, Beagrie G, Cutress T, Martin J, SardoInfirri J. Development of the World Health Organization (WHO) community periodontal index of treatment needs (CPITN). Int Dent J 1982;32:281–291. 2. Albandar JM, Buischi YAP, Mayer MPA, Axelsson P. Longterm effect of two preventive programs on the incidence of plaque and gingivitis in adolescents. J Periodontol 1994;65:605–610. 3. Axelsson P. Prophylaxe: Erfolge in Schweden. Phillip J Restaurative Zahnmed 1990;7:146–154. 4. Axelsson P, Lindhe J. Effect of controlled oral hygiene procedures on caries and periodontal disease in adults. J Clin Periodontol 1978;5:133–151. 5. Axelsson P, Lindhe J. Effect of controlled oral hygiene procedures on caries and periodontal disease in adults. Results after 6 years. J Clin Periodontol 1981;8:239–248. 6. Axelsson P, Lindhe J, Nystroem B. On the prevention of caries and periodontal disease. J Clin Periodontol 1991;18:182–189. 7. Bastendorf KD. Langzeiterfolge in der Prophylaxepraxis. Prophylaxe Impuls 2005;3:134–138. 8. Brozio V, Caspar G, Spranger H. Epidemiologische Untersuchungen an Soldaten der deutschen Bundeswehr und einer dem Alter nach vergleichbaren Studentengruppe. Dtsch Zahnaerztl Z 1982;37:461–464. 9. Buischi YA, Axelsson P, Oliveira LB, Mayer MP, Gjermo P. Effect of two preventive programs on oral health knowledge and habits among Brazilian schoolchildren. Community Dent Oral Epidemiol 1994;22:41–46. 10. Glavind L. Effect of monthly professional mechanical tooth cleaning on periodontal health in adults. J Clin Periodontol 1977;4:100–106. 11. Goebel G, Gaengler P. Kariesprogression und Gingivitisbefall bei Jugendlichen und jungen Erwachsenen nach 12 Jahren Longitudinalbetreuung. Dtsch Zahnaerztl Z 1992;47: 767–770. 12. Guelzow HJ. Grundlagen und Moeglichkeiten der Kariesund Gingivitisprophylaxe. Munich, Vienna: Carl Hanser Verlag, 1995. 13. Klimek J, Ganss C, Wagner R, Kielbassa AM, Stein K. Individualprophylaxe: Akzeptanz in der Praxis und Auswirkungen auf Plaque- und Gingiva- Index. Oralprophylaxe 1993;15:106–110. 14. Klimm W, Natusch I, Koch R. Wie effektiv ist die Individualprophylaxe? Dtsch Zahnaerztl Z 1994;49:809–811.
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• oral hygiene instruction significantly improves the oral hygiene status of the patients • increasing the awareness and the understanding of the importance of oral hygiene is essential for successful dental prophylaxis • group oral hygiene instruction that is provided in addition to dental care appears to be the most efficient and cost-effective method of dental prophylaxis.
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