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Flossing for 2 Weeks Reduces Microbes Associated with Oral Disease
DIAGNOSIS/TREATMENT/PROGNOSIS
ARTICLE ANALYSIS & EVALUATION ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION
Flossing for 2 Weeks Reduces Microbes Associated with Oral Disease
Treatment outcomes of dental flossing in twins: molecular analysis of the interproximal microflora. Corby PM, Biesbrock A, et al. J Periodontol 2008;79(8):1426-33.
SUMMARY
REVIEWER Anwar T. Merchant, ScD, MPH, DMD
PURPOSE/QUESTION Does flossing in addition to brushing the teeth and gums alter the microbial profile?
SOURCE OF FUNDING Industry: Proctor & Gamble Company, Mason, OH
Subjects There were 51 twin pairs (102 individuals) from Montes Carlos, Brazil, in this study. There were 31 monozygotic twin pairs (15 male, 16 female) and 20 dizygotic pairs (3 male-male, 13 male-female, 4 female-female). If either of the twins had used systemic antibiotics within 3 months of recruitment, or had any systemic condition interfering with oral examination, that pair of twins was excluded. The study was conducted from May through July 2005. Participants were examined for gingival bleeding at baseline and 2 weeks. Plaque samples were collected at baseline and 2 weeks from 6 sites per participant.
Key Exposure/Study Factor Each twin in a pair was randomized to 1 of 2 groups: manual toothbrush and toothpaste, and manual toothbrush, toothpaste, and floss. Morning tooth brushing and flossing were supervised on weekdays, whereas evenings and weekends were not.
Main Outcome Measure
LEVEL OF EVIDENCE
The main outcome measures were average changes in microbial abundance. Each plaque sample was evaluated for 26 selected oral microflora using the reverse capture checkerboard hybridization assay (mean counts per sample). These were converted in cubed roots and estimated average change in microbial abundance levels were estimated using caGEDA software.
Level 2: Limited-quality, patientoriented evidence
Main Results
STRENGTH OF RECOMMENDATION GRADE
Conclusions
TYPE OF STUDY/DESIGN Randomized controlled trial
Grade B: Inconsistent or limitedquality patient-oriented evidence
After 2 weeks, organisms that are hypothesized to cause periodontal disease and caries were present in greater numbers in the group that did not floss.
Flossing in addition to brushing teeth and tongue twice a day reduces organisms associated with periodontal disease and caries in 2 weeks.
COMMENTARY AND ANALYSIS
J Evid Base Dent Pract 2009;9:223-224 1532-3382/$34.00 Ó 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.jebdp.2009.05.005
There is surprisingly little evidence evaluating the effectiveness of flossing in relation to periodontal disease in particular. This study is thus a welcome addition. The authors show that organisms associated with periodontal disease and caries are reduced in 2 weeks with regular brushing and flossing. Its results are consistent with conventional wisdom on the subject. Dentists can feel more confident in recommending flossing to patients. The data were carefully collected and the laboratory analyses were of a high quality. The selection of twins controlled for genetic variation. Random allocation reduced the chances of confounding. Allocation concealment (knowledge of which treatment group the participant was in) was done for the persons examining the participants, but was not possible
JOURNAL OF EVIDENCE-BASED DENTAL PRACTICE
for the participants. There are no data on how often the participants returned to be observed flossing. There was also no information on chewing gum and mouthwash use. Both these factors can affect the outcome. It would have been useful to see the differences in the treatment and control groups in a table. Another issue with the presentation was that there were no units in any of the tables. Were they counts? Were they cubed roots of counts? What was the denominator of the counts? Where are the standard errors? There is no discussion on the power of the study or the issue of multiple testing. The unit of analysis seemed to be plaque samples and not the individual. We cannot be sure because none of the tables give the number of observations (N). This is
224
a potential problem because the plaque samples within a person are correlated. One way to address this issue would have been to use multilevel models. In summary, these were carefully collected data. A clearer analysis approach and presentation of the results would have enhanced this study.
REVIEWER Anwar T. Merchant, ScD, MPH, DMD Associate Professor, Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Office: 803-251-7874, Fax: 803-251-7873 [email protected]
December 2009
ARTICLE ANALYSIS & EVALUATION ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION
Flossing for 2 Weeks Reduces Microbes Associated with Oral Disease
Treatment outcomes of dental flossing in twins: molecular analysis of the interproximal microflora. Corby PM, Biesbrock A, et al. J Periodontol 2008;79(8):1426-33.
SUMMARY
REVIEWER Anwar T. Merchant, ScD, MPH, DMD
PURPOSE/QUESTION Does flossing in addition to brushing the teeth and gums alter the microbial profile?
SOURCE OF FUNDING Industry: Proctor & Gamble Company, Mason, OH
Subjects There were 51 twin pairs (102 individuals) from Montes Carlos, Brazil, in this study. There were 31 monozygotic twin pairs (15 male, 16 female) and 20 dizygotic pairs (3 male-male, 13 male-female, 4 female-female). If either of the twins had used systemic antibiotics within 3 months of recruitment, or had any systemic condition interfering with oral examination, that pair of twins was excluded. The study was conducted from May through July 2005. Participants were examined for gingival bleeding at baseline and 2 weeks. Plaque samples were collected at baseline and 2 weeks from 6 sites per participant.
Key Exposure/Study Factor Each twin in a pair was randomized to 1 of 2 groups: manual toothbrush and toothpaste, and manual toothbrush, toothpaste, and floss. Morning tooth brushing and flossing were supervised on weekdays, whereas evenings and weekends were not.
Main Outcome Measure
LEVEL OF EVIDENCE
The main outcome measures were average changes in microbial abundance. Each plaque sample was evaluated for 26 selected oral microflora using the reverse capture checkerboard hybridization assay (mean counts per sample). These were converted in cubed roots and estimated average change in microbial abundance levels were estimated using caGEDA software.
Level 2: Limited-quality, patientoriented evidence
Main Results
STRENGTH OF RECOMMENDATION GRADE
Conclusions
TYPE OF STUDY/DESIGN Randomized controlled trial
Grade B: Inconsistent or limitedquality patient-oriented evidence
After 2 weeks, organisms that are hypothesized to cause periodontal disease and caries were present in greater numbers in the group that did not floss.
Flossing in addition to brushing teeth and tongue twice a day reduces organisms associated with periodontal disease and caries in 2 weeks.
COMMENTARY AND ANALYSIS
J Evid Base Dent Pract 2009;9:223-224 1532-3382/$34.00 Ó 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.jebdp.2009.05.005
There is surprisingly little evidence evaluating the effectiveness of flossing in relation to periodontal disease in particular. This study is thus a welcome addition. The authors show that organisms associated with periodontal disease and caries are reduced in 2 weeks with regular brushing and flossing. Its results are consistent with conventional wisdom on the subject. Dentists can feel more confident in recommending flossing to patients. The data were carefully collected and the laboratory analyses were of a high quality. The selection of twins controlled for genetic variation. Random allocation reduced the chances of confounding. Allocation concealment (knowledge of which treatment group the participant was in) was done for the persons examining the participants, but was not possible
JOURNAL OF EVIDENCE-BASED DENTAL PRACTICE
for the participants. There are no data on how often the participants returned to be observed flossing. There was also no information on chewing gum and mouthwash use. Both these factors can affect the outcome. It would have been useful to see the differences in the treatment and control groups in a table. Another issue with the presentation was that there were no units in any of the tables. Were they counts? Were they cubed roots of counts? What was the denominator of the counts? Where are the standard errors? There is no discussion on the power of the study or the issue of multiple testing. The unit of analysis seemed to be plaque samples and not the individual. We cannot be sure because none of the tables give the number of observations (N). This is
224
a potential problem because the plaque samples within a person are correlated. One way to address this issue would have been to use multilevel models. In summary, these were carefully collected data. A clearer analysis approach and presentation of the results would have enhanced this study.
REVIEWER Anwar T. Merchant, ScD, MPH, DMD Associate Professor, Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Office: 803-251-7874, Fax: 803-251-7873 [email protected]
December 2009