Quality of trials in a systematic review of powered toothbrushes: suggestions for future clinical trials

A randomized, 3-month, parallel-group clinical trial to compare the efficacy of electric 3-dimensional toothbrushes vs manual toothbrushes in maintaining oral health in patients with fixed orthodontic appliances

INTRODUCTION

The aim of this single-blinded, parallel-group, randomized clinical trial was to compare the efficacy of electric 3-dimensional (3D) toothbrushes and manual toothbrushes in removing plaque and reducing gingival inflammation in orthodontic patients.

METHODS

Eighty adolescents with fixed orthodontic appliances in both arches were randomized at a 1:1 ratio, with an equal number of both sexes, in this examiner blinded, parallel clinical trial. Eligibility criteria included subjects aged between 12 and 16 years, good general health, nonextraction orthodontic treatment, and plaque-induced gingivitis, excluding patients with active caries or periodontitis, tooth agenesis, syndromes, disabilities, and craniofacial deformities, ≥2 cervical and/or proximal fillings, dental prostheses or dental implants, and subjects smoking or using antibiotics or medication predisposing to gingival enlargement. Patients were assigned to use either an electric 3D orthodontic toothbrush (Oral-B Pro-1000 with Oral-B Ortho head; Procter & Gamble, Cincinnati, Ohio) or a manual toothbrush (Oral-B Orthodontic brush; Procter & Gamble) and instructed to brush twice daily for 2 minutes. The main outcomes were: (1) plaque removal, assessed with the Modified Silness and Löe plaque index and the Modified Full Mouth Plaque Score, and (2) gingival inflammation reduction, assessed with the Modified Silness and Löe Gingival Index and the Modified Simplified Gingival Index. Measurements were taken at baseline, 1, 2, and 3 months. Randomization was achieved with 2 random sequences, one for each brush, written and sealed in opaque numbered envelopes. Blinding was possible for outcome assessment only.

RESULTS

Considerable variability was observed among patients in the values of all dependent variables. There was no difference between interventions over time for any of the outcomes, and the main effects for treatment and time were also not statistically significant. For Modified Silness and Löe plaque index, the interaction was 0.001 (95% confidence interval, -0.011 to 0.013; P = 0.89).

CONCLUSIONS

No difference in plaque removal efficacy and gingival inflammation reduction was found between the electric 3D and manual toothbrushes in adolescents with fixed orthodontic appliances. Therefore, orthodontists should focus on enhancing their patients' dental awareness and oral hygiene, along with professional prophylaxis and other oral hygiene aids, independently of the brush used.

REGISTRATION

This trial was registered at ClinicalTrials.gov (Identifier: NCT02699931).

PROTOCOL

The protocol was not published before trial commencement.

FUNDING

Electric and manual toothbrushes and toothpastes for all participants were provided by Procter & Gamble (Oral-B). Miscellaneous costs were covered by the participating departments.

Randomised methodology development study to investigate plaque removal efficacy of manual toothbrushes

OBJECTIVES

This study aimed to evaluate plaque removal efficacy of toothbrushes to guide clinical model development.

METHODS

This single-centre, randomised, controlled, examiner-blind, method development study included 80 healthy participants. Over 28 days, participants brushed twice-daily using a fluoride toothpaste and one of four marketed toothbrushes: Toothbrushes A (compact head) and B (regular head): medium-hard; flat trim; end-rounded bristles; Toothbrush C: medium-hard; end-rounded bristles; silky, tapered filaments; compact head; Toothbrush D: soft; tapered filaments; compact head. Supra-gingival plaque removal was evaluated immediately after single brushing events (Days 0, 7, 28, at study centre) and following 7- and 28-days' home use via Rustogi modified Navy Plaque Index (RPI) and Turesky modified Quigley Hein Plaque Index (TPI).

RESULTS

All toothbrushes provided significant plaque removal after single-brushing events with change from Day 0 pre-brushing scores on RPI ranging from -0.10 to -0.16 (p<.0001) and on TPI ranging from -0.61 to -0.89 (p<.0001). Toothbrushes A and B showed significant (p<.05) pre-brushing RPI/TPI plaque reductions after 7- (-0.04/-0.06, respectively for RPI; -0.16/-0.20, respectively for TPI) and 28-days (-0.04/-0.03, respectively for RPI; -0.20/-0.11, respectively for TPI) use versus Day 0 pre-brushing (except Toothbrush B, Day 28, non-significant TPI). There were no significant differences with Toothbrush C. Toothbrush D TPI was significantly lower at both timepoints versus Day 0 pre-brushing (p<.05). Study toothbrushes were generally well-tolerated.

CONCLUSION

The observations from this study showed how various aspects of a study design could impact toothbrushes performance. These data will inform the design of future clinical studies of plaque removal efficacy using manual toothbrushes.

CLINICAL SIGNIFICANCE STATEMENT

Regular effective oral hygiene can help prevent and treat gingivitis, principally via twice-daily mechanical cleaning with a toothbrush. Data generated from this methodology development study will help to identify the key aspects which impact toothbrushes' performance and understand which one would be more suitable to answer questions of scientific interest. This study provides useful information for the design of future clinical trials to assess plaque removal efficacy of manual toothbrushes and generate results to inform clinical recommendations.

Randomised clinical study of plaque removal efficacy of a power toothbrush in a paediatric population

BACKGROUND

Clinical investigations of plaque removal efficacy of power toothbrushes in children are limited.

AIM

To compare plaque removal of a power versus manual toothbrush in a paediatric population.

DESIGN

This was a randomised, replicate-use, single-brushing, examiner-blinded, two-treatment, four-period crossover clinical trial in children 8-11 years of age. Subjects were randomly assigned to a treatment sequence involving an oscillating-rotating power toothbrush and a manual toothbrush control. Subjects brushed under supervision with a NaF dentifrice. Plaque was assessed pre- (baseline) and post-brushing using the Turesky Modification of the Quigley-Hein Plaque Index by two examiners. Plaque scores were averaged for mixed and permanent dentition on a per-subject basis and analysed using a mixed-model ancova for a crossover design.

RESULTS

Forty-one subjects (mean 9.0 years) were randomised and completed the trial. Both the power brush and manual brush provided statistically significant mean plaque reductions versus baseline in all analyses (P < 0.001). For both examiners, plaque removal was significantly (P < 0.001) larger for the power brush in permanent and mixed dentitions. The interexaminer correlations for the permanent dentition were strong (ICC = 0.68-0.88) for pre-brushing plaque across all periods.

CONCLUSIONS

An oscillating-rotating power toothbrush provided superior plaque reduction versus a manual toothbrush in children.

Oral hygiene-related self-efficacy as a predictor of oral hygiene behaviour: a prospective cohort study

AIM

The aim of this study was to assess whether oral hygiene-related self-efficacy is correlated with current oral hygiene and might influence the outcome of oral hygiene instruction.

MATERIALS AND METHODS

Hundred and twenty-six patients filled out questionnaires about oral hygiene-related self-efficacy, general self-efficacy, oral hygiene-related knowledge and demographic variables. Plaque and gingival inflammation were measured and an individual oral hygiene plan was conducted. After 6 months, oral hygiene indices were assessed again.

RESULTS

Women had significantly higher scores in oral hygiene-related self-efficacy than men (women mean 60.40 ± 9.41; men mean 56.04 ± 11.55; p = 0.039) and oral hygiene-related self-efficacy was significantly correlated with general self-efficacy independent from the age of the patients (r = 0.3114, p = 0.0004). Higher scores in oral hygiene-related self-efficacy were significantly correlated with lower scores of gingival bleeding for non-smoking patients (r = -0.301, p = 0.0066), usage of a professional tooth cleaning within these 6 months (p = 0.0406), reappearance to the follow-up appointment (p = 0.0303), and higher goals in inter-dental cleaning plans (p = 0.0189).

CONCLUSION

Oral hygiene-related self-efficacy is an influencing factor in the oral hygiene behaviour and has the potential to predict patients' oral hygiene outcomes.

Oral health research: A source for innovative new statistical developments

This article reviews the challenges and opportunities that oral health research may offer to a statistician. To illustrate this, we focus on the Signal Tandmobiel® study, a longitudinal oral health survey that triggered many statistical explorations and developments over the last two decades. For example, non-standard distributions are more the rule than the exception in oral health research. In addition, often measurement error problems need to be addressed. The hierarchical structure of the oral health data also poses non-standard challenges. For instance, caries experience in the mouth is spatially correlated with, however, a specific metric defining the distance between two occurrences. In addition, since caries experience in the context of an epidemiological study is only measured at intervals, analysis of survival involves interval-censoring. Finally, when analyzing a realistic data set in oral health, all the above issues may have to be dealt with simultaneously.

Moderate quality evidence finds statistical benefit in oral health for powered over manual toothbrushes

DATA SOURCES

The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, Embase, CINAHL, National Institutes of Health Trials Register and the WHO Clinical Trials Registry Platform for ongoing trials. Reference lists of identified articles were also scanned for relevant papers. Identified manufacturers were contacted for additional information.

STUDY SELECTION

Only randomised controlled trials comparing manual and powered toothbrushes were considered. Crossover trials were eligible for inclusion if the wash-out period length was more than two weeks.

DATA EXTRACTION AND SYNTHESIS

Study assessment and data extraction were carried out independently by at least two reviewers. The primary outcome measures were quantified levels of plaque or gingivitis. Risk of bias assessment was undertaken. Standard Cochrane methodological approaches were taken. Random-effects models were used provided there were four or more studies included in the meta-analysis, otherwise fixed-effect models were used. Data were classed as short term (one to three months) and long term (greater than three months).

RESULTS

Fifty-six trials were included with 51 (4624 patients) providing data for meta-analysis. The majority (46) were at unclear risk of bias, five at high risk of bias and five at low risk. There was moderate quality evidence that powered toothbrushes provide a statistically significant benefit compared with manual toothbrushes with regard to the reduction of plaque in both the short and long-term. This corresponds to an 11% reduction in plaque for the Quigley Hein index (Turesky) in the short term and a 21% reduction in the long term. There was a high degree of heterogeneity that was not explained by the different powered toothbrush type subgroups.There was also moderate quality evidence that powered toothbrushes again provide a statistically significant reduction in gingivitis when compared with manual toothbrushes both in the short and long term. This corresponds to a 6% and 11% reduction in gingivitis for the Löe and Silness indices respectively. Again there was a high degree of heterogeneity that was not explained by the different powered toothbrush type subgroups. The greatest body of evidence was for rotation oscillation brushes which demonstrated a statistically significant reduction in plaque and gingivitis at both time points.

CONCLUSIONS

Powered toothbrushes reduce plaque and gingivitis more than manual toothbrushing in the short and long term. The clinical importance of these findings remains unclear. Observation of methodological guidelines and greater standardisation of design would benefit both future trials and meta-analyses. Cost, reliability and side effects were inconsistently reported. Any reported side effects were localised and only temporary.

Powered versus manual toothbrushing for oral health

BACKGROUND

Removing dental plaque may play a key role maintaining oral health. There is conflicting evidence for the relative merits of manual and powered toothbrushing in achieving this. This is an update of a Cochrane review first published in 2003, and previously updated in 2005.

OBJECTIVES

To compare manual and powered toothbrushes in everyday use, by people of any age, in relation to the removal of plaque, the health of the gingivae, staining and calculus, dependability, adverse effects and cost.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 23 January 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE via OVID (1946 to 23 January 2014), EMBASE via OVID (1980 to 23 January 2014) and CINAHL via EBSCO (1980 to 23 January 2014). We searched the US National Institutes of Health Trials Register and the WHO Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

Randomised controlled trials of at least four weeks of unsupervised powered toothbrushing versus manual toothbrushing for oral health in children and adults.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by The Cochrane Collaboration. Random-effects models were used provided there were four or more studies included in the meta-analysis, otherwise fixed-effect models were used. Data were classed as short term (one to three months) and long term (greater than three months).

MAIN RESULTS

Fifty-six trials met the inclusion criteria; 51 trials involving 4624 participants provided data for meta-analysis. Five trials were at low risk of bias, five at high and 46 at unclear risk of bias.There is moderate quality evidence that powered toothbrushes provide a statistically significant benefit compared with manual toothbrushes with regard to the reduction of plaque in both the short term (standardised mean difference (SMD) -0.50 (95% confidence interval (CI) -0.70 to -0.31); 40 trials, n = 2871) and long term (SMD -0.47 (95% CI -0.82 to -0.11; 14 trials, n = 978). These results correspond to an 11% reduction in plaque for the Quigley Hein index (Turesky) in the short term and 21% reduction long term. Both meta-analyses showed high levels of heterogeneity (I(2) = 83% and 86% respectively) that was not explained by the different powered toothbrush type subgroups.With regard to gingivitis, there is moderate quality evidence that powered toothbrushes again provide a statistically significant benefit when compared with manual toothbrushes both in the short term (SMD -0.43 (95% CI -0.60 to -0.25); 44 trials, n = 3345) and long term (SMD -0.21 (95% CI -0.31 to -0.12); 16 trials, n = 1645). This corresponds to a 6% and 11% reduction in gingivitis for the Löe and Silness index respectively. Both meta-analyses showed high levels of heterogeneity (I(2) = 82% and 51% respectively) that was not explained by the different powered toothbrush type subgroups.The number of trials for each type of powered toothbrush varied: side to side (10 trials), counter oscillation (five trials), rotation oscillation (27 trials), circular (two trials), ultrasonic (seven trials), ionic (four trials) and unknown (five trials). The greatest body of evidence was for rotation oscillation brushes which demonstrated a statistically significant reduction in plaque and gingivitis at both time points.

AUTHORS' CONCLUSIONS

Powered toothbrushes reduce plaque and gingivitis more than manual toothbrushing in the short and long term. The clinical importance of these findings remains unclear. Observation of methodological guidelines and greater standardisation of design would benefit both future trials and meta-analyses.Cost, reliability and side effects were inconsistently reported. Any reported side effects were localised and only temporary.

Different powered toothbrushes for plaque control and gingival health

BACKGROUND

Powered brushes were first introduced commercially in the 1960s. A recent systematic review suggested the superiority of certain modes of powered over manual toothbrushing for plaque and gingivitis reduction. That review did not allow for direct comparison between different modes of powered toothbrush.

OBJECTIVES

To compare different modes of powered toothbrushing against each other for plaque reduction and the health of the gingivae. Other factors to be assessed were calculus and stain removal, cost, dependability and adverse effects.

SEARCH STRATEGY

The following databases were searched: Cochrane Oral Health Group's Trials Register (to 26 July 2010); Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2010, Issue 3); MEDLINE via OVID (1950 to 26 July 2010); EMBASE via OVID (1980 to 26 July 2010); CINAHL via EBSCO (1982 to 26 July 2010). There were no language restrictions.

SELECTION CRITERIA

Trials were considered for inclusion with the following criteria: random allocation of participants; no compromised manual dexterity; unsupervised powered toothbrushing for at least 4 weeks. The primary outcomes were the plaque and gingivitis scores after powered toothbrush use during trial period.

DATA COLLECTION AND ANALYSIS

Data extraction was performed independently and in duplicate. The authors of trials were contacted to provide missing data where possible. The effect measure for each meta-analysis was the standardised mean difference (SMD) with 95% confidence intervals (CI) using the random-effects model. Potential sources of heterogeneity were assessed.

MAIN RESULTS

The review included data from 15 trials with 1015 participants. Due to the dearth of trials assessing the same mode of action, no definitive conclusions can be stated regarding the superiority of one mode of powered toothbrush over any other. Only minor and transient side effects were reported. Cost, dependability were not reported.

AUTHORS' CONCLUSIONS

Further trials of good quality are required to establish if any mode of action has superiority over the other modes of action for powered toothbrushes.