Relationship between the plaque removal efficacy of a manual toothbrush and brushing force

A systematic review of the effectiveness of self-performed mechanical plaque removal in adults with gingivitis using a manual toothbrush

OBJECTIVE

To assess the effectiveness of self-performed mechanical plaque removal in adults with gingivitis using a manual toothbrush with respect to the level of plaque and gingivitis in controlled studies of at least 6 months duration. SEARCH: Medline-PubMed up to and including September 2004.

RESULTS

Out of 3223 titles and abstracts, 33 trials were found for data extraction. A meta-analysis was conducted of studies (n=9) in which, for the manual toothbrush group at baseline, only a professional prophylaxis provided. The weighted mean differences (WMD) between baseline and end-trial for the Quigley & Hein plaque index was 0.28 and 0.21 for the Gingival Index (p<0.05). Eight studies provided both a professional OHI and prophylaxis at baseline. The WMD for the Silness & Löe Plaque Index was 0.10 (ns). The WMD of the proportion of bleeding sites was 5.84% (p<0.05).

CONCLUSION

In adults with gingivitis the quality of self-performed mechanical plaque removal is not sufficiently effective and should be improved. Based on studies > or = 6 months of duration, it appears that a single oral hygiene instruction, describing the use of a mechanical toothbrush, in addition to a single professional 'oral prophylaxis' provided at baseline, had a significant, albeit small, positive effect on the reduction of gingivitis.

The measurement in vitro of enamel and dentine wear by toothpastes of different abrasivity

OBJECTIVES

To investigate the in vitro enamel and dentine wear by toothpastes with a range of Relative Dentine Abrasivity (RDA) and Relative Enamel Abrasivity (REA) values.

METHODS

Human enamel/dentine (approximately 50:50) blocks (approximately 4 x 4 mm) were polished and the enamel indented with four Knoop indents. The step across the enamel-dentine junction was measured by interference microscopy. Specimens were brushed in vitro with toothpastes with a range of RDA/REA values using a flat trim toothbrush mounted in a Wira brushing machine for 360 s and a load of 375 g. After brushing the Knoop indent length and the enamel-dentine step were remeasured and the amount of wear to the enamel and dentine was calculated.

RESULTS

The mean enamel wear ranged from 0.05 to 0.40 microns, with the highest wear for the highest REA product. The mean dentine wear for all toothpaste products tested was positively correlated with RDA value (R2 = 0.897). The correlation was further improved if median wear values were used (R2 = 0.930).

CONCLUSIONS

This study has demonstrated a rapid technique for the simultaneous investigation of the abrasive wear of toothpaste on enamel and dentine. There was a good correlation between median dentine wear and RDA values.

Optimal rinsing time for intra-oral distribution (spread) of mouthwashes

AIM

To investigate the intra-oral spread of an erythrosine mouthwash in relation to the rinsing period.

MATERIAL AND METHODS

Thirty subjects were randomly divided into two equal groups and asked to rinse with 10 ml erythrosine mouthwash for cumulative periods of 15, 30 and 60 s (Group I) and 30, 60 and 90 s (Group II). Each rinsing session was followed by new plaque measurements. After rinsing plaque was finally assessed using the erythrosine mouthwash applied by means of a cotton swab.

RESULTS

In Group I there was a difference observed between the 15 s rinsing period and those of 30 and 60 s. Explorative analysis for Group I suggested that differences in both jaws and approximal sites on both vestibular and lingual surfaces appeared to have contributed to the overall difference seen between 15 and 30 s rinsing periods. Also, pre-molars and front teeth seem to have contributed to this observed difference. No differences were noted between rinsing sessions and cotton swab application for Group II or Groups I+II combined.

CONCLUSIONS

Rinsing for 30 s appeared to be sufficient for all plaque-covered surfaces of the dentition to come into contact with the mouthwash.

High and low brushing force in relation to efficacy and gingival abrasion

OBJECTIVES

Does a high brushing force induce more gingival abrasion than a low (regular) brushing force? Furthermore, what is the effect of a low or high force on the efficacy?

METHODS

Thirty-five non-dental students were selected. All received an appointment prior to which they abstained from oral hygiene for at least 48 h. At baseline the teeth and surrounding tissues were disclosed using Mira-2-Tone disclosing solution. Next, the examiner (PAV) evaluated the number of sites with gingival abrasion and the amount of dental plaque (Quigley & Hein) at 6 surfaces of each tooth. In the absence of this examiner, the subject's teeth were brushed by a hygienist (MP) using the Braun/Oral-B-D17 oscillating rotating toothbrush. Brushing was performed in two randomly selected contra-lateral quadrants for 60 s with either a low force (+/-1.5 N) or high force (+/-3.5 N) and in the opposing quadrants for 60 s with the alternative force. Visual feedback was given to control force. The brush was moved from the distal tooth to the central incisor perpendicular to the tooth surface with an angle of approximately 10-15 degrees towards the gingival margin. Next, the number of sites with abrasion and the remaining plaque were assessed again.

RESULTS

The overall baseline gingival abrasion scores were 3.1 and 3.2 sites for high and low force, respectively, and increased to 5.0 and 5.9 sites respectively after brushing. There was no significant difference with respect to incidence of abrasion. At baseline, 48 h. plaque levels were 2.2. The reduction in plaque scores with the low force was 60% and with the high force 56%. This difference was significant.

CONCLUSION

With the oscillating rotating power toothbrush (Braun/Oral-B D17) the use of high force (+/-3.5 N) is less efficacious as compared to a regular low force (+/-1.5 N) while the incidence of gingival abrasion sites was comparable.

Optimum force and duration of toothbrushing to enhance gingival fibroblast proliferation and procollagen type I synthesis in dogs

BACKGROUND

Toothbrushing enhances gingival fibroblast proliferation, which promotes wound healing. Optimum force and duration of toothbrushing for stimulation of fibroblast proliferation are key factors in maximizing effects of toothbrushing on periodontal wound healing. We therefore evaluated the effects of different durations and forces of toothbrushing on proliferative activity and procollagen synthesis of gingival fibroblasts.

METHODS

Twelve dogs were used. In each dog, buccal gingivae of 12 teeth were examined for 3 weeks. Nine of these 12 teeth were each assigned to 1 of 9 different combinations of brushing force (0.98, 1.96, or 2.45 N) and duration (10, 20, or 40 seconds). The remaining 3 teeth received plaque removal without brushing, via a scaler.

RESULTS

Force and duration of toothbrushing affected both proliferating cell nuclear antigen (PCNA)-positive and procollagen Type I C-peptide (PIP)-positive fibroblast ratios (P < 0.05). The highest ratio of PCNA-positive fibroblasts was produced by brushing at 1.96 N for 20 seconds. The highest ratio of PIP-positive fibroblasts was produced by brushing at 1.96 N for 10 seconds.

CONCLUSIONS

Toothbrushing at certain forces and durations enhanced the proliferative activity and procollagen synthesis of gingival fibroblasts. The toothbrushing duration that increased procollagen synthesis (10 seconds) was shorter than that which increased fibroblast proliferative activity (20 seconds).

Effect of brushing force and time on plaque removal using a powered toothbrush

OBJECTIVES

Primary objective - To determine the effect of varying brushing forces and brushing times upon the plaque-removing efficacy of a powered toothbrush. Secondary objective - to determine the optimum combination of brushing force and time for plaque removal.

MATERIAL AND METHODS

This randomised, single-blind, 16-cell, cross-over trial compared the efficacy of plaque removal of a powered toothbrush (PTB) used with four brushing forces (75, 150, 225 and 300 g) and over four brushing times (30, 60, 120 and 180 s). Twelve volunteers (18-30 years) were recruited and trained to use the Philips/Jordan Sensiflex 2000 PTB, which was modified so that specified forces and times could be recorded. Each subject was asked to abstain from all oral hygiene procedures for 24 hs prior to each brushing event, to allow plaque accumulation. Plaque was recorded using a modified Quigley & Hein index (PI) at six points per tooth before and after each episode of brushing, and the differences in the means (pre- to postbrushing) were compared. Three-way anova was undertaken to compare differences between plaque-removing efficacy for the 16 combinations of force and time. Subjects, brushing time and brushing force were used as fixed effects within the analysis.

RESULTS

All 12 subjects participating completed the 16 combinations of force and time over which plaque removal was assessed. Statistically significant differences in PI reductions were found between different brushing times and forces over all tooth surfaces (p<0.001). The interaction of varying brushing force and brushing time was significant for full mouth (FM) and interproximal (IP) sites (p<0.03). No statistical significance was demonstrated for smooth surface (SS) sites, nor was it detected for the interaction of subjects with brushing force or subjects with brushing time (p>0.05).

CONCLUSION

We conclude that brushing time and brushing force have significant effects upon the level of plaque removal by a PTB, and at 120 s brushing time the improvement in plaque removal with forces in excess of 150 g was negligible.

Effectiveness of an electrically active brush in the removal of overnight plaque and treatment of gingivitis

OBJECTIVES

The purpose of the present study was to evaluate the effect of an electrically active toothbrush on established plaque and gingivitis in a 7-month clinical trial.

MATERIAL AND METHODS

For this study, 66 volunteers (non-dental University students) were selected on the basis of having moderate gingival inflammation. At baseline, plaque (Quigley & Hein), bleeding upon marginal probing and the Modified Gingival index were assessed on the vestibular, mesio-vestibular, disto-vestibular and lingual surfaces at four sites per tooth. Subjects were randomly divided among two groups; one group brushed with a control brush (Butler GUM 309) while the other used the electrically active test brush. After 2 weeks, 4 weeks, 4 months and 7 months the clinical indices were again recorded. At each assessment the participants received a new brush head for the electrically active brush (test group) or a new manual control toothbrush (control group).

RESULTS

All baseline indices appeared to be well balanced. A mean Quigley & Hein plaque score of 1.98 and 2.13 was found in the control and test group, respectively. Little change was observed from baseline to 7 months. The mean bleeding upon marginal probing score at baseline was 0.62 for the control group and 0.59 for the test group. Little to no improvement was observed for the manual brush, whereas an increase in bleeding was observed in the test group in the course of this study. The mean percent reduction in plaque after 1 min of brushing varied throughout the study between 36% and 46%. No difference between the brushes was observed at any time point during the 7-month test period.

CONCLUSION

No beneficial effect could be shown for the 'electrically active design feature' compared to a regular manual toothbrush control.

Antimicrobial effects of mechanical debridement

Self-performed plaque removal using manual or powered toothbrushes and interdental cleaning devices is improved in subjects that have received oral hygiene instructions. Personal oral hygiene coupled with regular professional supragingival debridement may further improve the level of plaque control but still fails to achieve a completely plaque-free dentition. Both patient-performed and professional supragingival plaque removal has an effect on subgingival microbiota that is limited to the marginal 3 mm of the periodontal pocket. At sites with 4 mm or more of probing depth, only subgingival scaling leads to a significant reduction of the bacterial load. The subgingival microflora can be further reduced by pocket elimination surgery. Due to the sequence of bacterial recolonization that occurs following mechanical debridement, the level of periodontal pathogens such as B. forsythus, P. gingivalis and T. denticola may be reduced for several months. Mechanical debridement also influences the patient's immune system response, resulting in antibody titers and avidity against periodontal pathogens. As a basis for the restoration and maintenance of periodontal health, repeated subgingival debridement, as performed in supportive periodontal therapy, can reduce the number and proportions of periodontopathogenic bacteria in subgingival plaque. However, intensive subgingival scaling and root planing should be avoided in sites that probe less than 3 mm, as this is likely to traumatize the periodontium and cause attachment loss.

Models for assessing powered toothbrushes

The continued development of the power toothbrush over the last 25 years has led to some present-day models that demonstrate increased efficacy in plaque removal compared with a manual brush. The wealth of clinical data that supports these claims has a reference to both in vitro and in vivo models. An overview of performance evidence compared with manual toothbrushes must also be considered from a research model view. The issue of power toothbrush safety in relation to soft tissue abrasion will offer an opportunity for the review of the scientific facts behind any fictitious "hype". Specific studies will provide clinical evidence on power toothbrush safety and performance. This paper will consider implications of the evidence for the use of powered toothbrushes in clinical practice and will emphasize the current consensus of clinical opinion in the light of scientific evidence.

Effectiveness of a dental gel to reduce plaque in beagle dogs

Tooth brushing is considered a superior technique for reducing plaque accumulation. Chemical agents may be used to reduce plaque accumulation on tooth surfaces since many owners may not be willing or able to brush their dog's teeth. Following a professional teeth cleaning procedure, a dental gel containing chlorhexidine was applied in 11 dogs BID for 7-days, while 11 other dogs received a control dental gel applied in the same manner. Dogs in the treatment group had significantly less plaque accumulation during the trial period compared with dogs in the control group. The dental gel applied in the study reported here decreases plaque accumulation in the short-term and may be beneficial in reducing the severity of gingivitis and associated periodontal disease if provided on a long-term basis.