Antimicrobial penetration in a dual-species oral biofilm after noncontact brushing: an in vitro study

Objectives

Oral biofilm is inevitably left behind, even after powered brushing. As a special feature, powered brushing removes biofilm in a noncontact mode. When the brushing distance becomes too large, biofilm is left behind. We hypothesize that biofilm left behind after brushing has different viscoelastic properties than before brushing, impacting antimicrobial penetration.

Materials and methods

In vitro grown dual-species biofilms were subjected to 20 % mechanical deformation before and after powered brushing at 4-mm brushing distance. Biofilm thickness and stress relaxation were measured for unbrushed and brushed biofilms. Stress relaxation was analyzed with a three-element Maxwell model. Antimicrobial penetration from five mouthrinses was microscopically evaluated for unbrushed and brushed biofilms.

Results

Thicknesses of unbrushed and brushed biofilms were similar. Brushing decreased the prevalence of fast and increased the prevalence of slow relaxation elements, which was accompanied by deeper penetration of chlorhexidine and cetylpyridinium chloride. Penetration of antimicrobials from other mouthrinses was relatively low in unbrushed and brushed biofilms.

Conclusions

This confirmation of our hypothesis points to an additional advantage of powered toothbrushing in a noncontact mode, changing the viscoelastic properties of biofilm in a direction that increases antimicrobial penetration of chlorhexidine and cetylpyridinium.

Clinical relevance

The biofilm left behind after noncontact powered toothbrushing may have less recalcitrance toward penetration of chlorhexidine and cetylpyridinium chloride than prior to brushing.     

Brushing without brushing?—a review of the efficacy of powered toothbrushes in noncontact biofilm removal

Objectives

The aim of the present review was to analyze the impact of the hydrodynamic effects created by powered toothbrushes on biofilm removal in vitro.

Materials and methods

A MEDLINE search was performed for publications published by 20 May 2012; this search was complemented by a manual search. The study selection, data preparation, and validity assessment were conducted by two reviewers.

Results

Sixteen studies were included. The studies differed with respect to the methods of biofilm formation and brushing protocols. Eighteen different powered toothbrush models were evaluated. Toothbrushes with side-to-side action demonstrated biofilm removal without direct bristle contact to biofilms ranging from 38 to 99 %. Most studies found biofilm removal exceeding 50 %. Biofilm reduction using multidimensional toothbrushes was significantly lower than by those with the side-to-side mode. Detachment forces due to hydrodynamic phenomena, passing air–liquid interfaces, and acoustic energy transfer were suggested to cause reduction of the biofilm.

Conclusion

Noncontact biofilm reduction was obtained by the hydrodynamic effects of some powered toothbrushes in vitro.

Clinical relevance

Powered toothbrushes may have the potential to simplify self-performed oral hygiene. However, additional beneficial effects of higher amounts of noncontact biofilm removal in vitro have not been shown clinically, yet.     

Brushing force of manual and sonic toothbrushes affects dental hard tissue abrasion

Objectives

This study aimed to determine the brushing forces applied during in vivo toothbrushing with manual and sonic toothbrushes and to analyse the effect of these brushing forces on abrasion of sound and eroded enamel and dentin in vitro.

Materials and methods

Brushing forces of a manual and two sonic toothbrushes (low and high frequency mode) were measured in 27 adults before and after instruction of the respective brushing technique and statistically analysed by repeated measures analysis of variance (ANOVA). In the in vitro experiment, sound and eroded enamel and dentin specimens (each subgroup n?=?12) were brushed in an automatic brushing machine with the respective brushing forces using a fluoridated toothpaste slurry. Abrasion was determined by profilometry and statistically analysed by one-way ANOVA.

Results

Average brushing force of the manual toothbrush (1.6?±?0.3 N) was significantly higher than for the sonic toothbrushes (0.9?±?0.2 N), which were not significantly different from each other. Brushing force prior and after instruction of the brushing technique was not significantly different. The manual toothbrush caused highest abrasion of sound and eroded dentin, but lowest on sound enamel. No significant differences were detected on eroded enamel.

Conclusion

Brushing forces of manual and sonic toothbrushes are different and affect their abrasive capacity.

Clinical significance

Patients with severe tooth wear and exposed and/or eroded dentin surfaces should use sonic toothbrushes to reduce abrasion, while patients without tooth wear or with erosive lesions confining only to enamel do not benefit from sonic toothbrushes with regard to abrasion.     

Analysis of tooth brushing cycles

Objective

The aim of this study was to demonstrate the effectiveness of an analysis of tooth brushing cycles using a system that measures tooth brushing motion and brushing force with an accelerometer and strain tension gage attached to a toothbrush.

Background

Mechanical plaque removal with a manual toothbrush remains the primary method of maintaining good oral hygiene for the majority of the population. Because toothbrush motion has not been fully understood, it should be clarified by analysis of tooth brushing cycles.

Methods

Twenty healthy female dental hygienists participated in this study. Their tooth brushing motions were measured and analyzed using an American Dental Association-approved manual toothbrush to which a three-dimensional (3-D) accelerometer and strain tension gage were attached. 3-D motion and brushing force on the labial surface of the mandibular right central incisor and the lingual surface of the mandibular left first molar were measured, analyzed, and compared. Multilevel linear model analysis was applied to estimate variables and compare motion and forces related to the two tooth surfaces.

Results

The analysis of tooth brushing cycles was feasible, and significant differences were detected for durations and 3-D ranges of toothbrush motion as well as brushing force between the two tooth surfaces.

Conclusion

The analysis used in this study demonstrated an ability to detect characteristics of tooth brushing motion, showing tooth brushing motion to change depending on the brushed location. These results also suggest that more detailed instructions might be required according to patient’s oral condition.     

Efficacy of various side-to-side toothbrushes for noncontact biofilm removal

Objectives

The aim of this study was to evaluate the efficacy of four different powered toothbrushes with side-to-side action for noncontact biofilm removal in vitro.

Materials and methods

A three-species biofilm was formed in vitro on protein-coated titanium disks using a flow chamber combined with a static biofilm growth model. Subsequently, the biofilm-coated substrates were exposed to four different side-to-side toothbrushes (A, B, C, and D) with various brushing times (2, 4, and 6 s) and brushing (bristle-to-disk) distances (0, 2, and 4 mm). The biofilm volumes were measured using volumetric analyses with confocal laser scanning microscope images and Imaris version 7.5.2 software.

Results

The median percentages of biofilm reduction by the analyzed toothbrushes ranged from 9 % to 80 %. The abilities of the tested toothbrushes to remove the in vitro biofilm differed significantly (p?<?0.05). Two of the tested toothbrushes (C and D) were capable of significant biofilm reduction by noncontact brushing.

Conclusions

It was possible to reduce a three-species in vitro biofilm by noncontact brushing with two out of four side-to-side toothbrushes.

Clinical relevance

Toothbrushes C and D show in vitro a high efficacy in biofilm removal without bristle contact.     

Effects of whitening dentifrice on yttria-stabilized tetragonal zirconia polycrystal surfaces after simulating brushing

Statement of problem

The changes that occur after brushing yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) are unknown. These changes may favor the retention of microorganisms and chemisorption of water, impairing its longevity.

Plaque-left-behind after brushing: intra-oral reservoir for antibacterial toothpaste ingredients

Objectives

Plaque is never fully removed by brushing and may act as a reservoir for antibacterial ingredients, contributing to their substantive action. This study investigates the contribution of plaque-left-behind and saliva towards substantivity of three antibacterial toothpastes versus a control paste without antibacterial claims.

Materials and methods

First, volunteers brushed 2?weeks with a control or antibacterial toothpaste. Next, plaque and saliva samples were collected 6 and 12?h after brushing and bacterial concentrations and viabilities were measured. The contributions of plaque and saliva towards substantivity were determined by combining control plaques with experimental plaque or saliva samples and subsequently assessing their viabilities. Bacterial compositions in the various plaque and saliva samples were compared using denaturing gradient gel electrophoresis.

Results

The viabilities of plaques after brushing with Colgate-Total? and Crest-Pro-Health? were smaller than of control plaques and up to 12?h after brushing with Crest-Pro-Health? plaques still contained effective, residual antibacterial activity against control plaques. No effective, residual antibacterial activity could be measured in saliva samples after brushing. There was no significant difference in bacterial composition of plaque or saliva after brushing with the different toothpastes.

Conclusions

Plaque-left-behind after mechanical cleaning contributes to the substantive action of an antibacterial toothpaste containing stannous fluoride (Crest-Pro-Health?).

Clinical relevance

The absorptive capacity of plaque-left-behind after brushing is of utmost clinical importance, since plaque is predominantly left behind in places where its removal and effective killing matter most. Therewith this study demonstrates a clear and new beneficial effect of the use of antibacterial toothpastes.     

Effect of sonic application mode on the resin–dentin bond strength and nanoleakage of simplified self-etch adhesive

Objectives

This study aims to evaluate the effect of different application modes on the immediate and 6-month resin–dentin bond strength (μTBS) and nanoleakage in the hybrid and adhesive layers.

Materials and methods

Three 1-step self-etch adhesives (One Coat 7.0 (OC), Clearfil S³ Bond (CS), and FuturaBond NR (FB)) were applied on a flat superficial dentin surface of 30 human molars under manual mode or sonic vibration at a frequency of 170 Hz (SV). Composite build-ups were constructed incrementally; specimens were sectioned to obtain resin–dentin sticks with cross-sectional area of 0.8 mm² and tested in tension (0.5 mm/min) immediately (IM) or after 6 months (6M) of water storage. Two bonded sticks, from each tooth at each storage time, were immersed in a silver nitrate solution, photo-developed, and analyzed under scanning electron microscopy. The amount of nanoleakage was measured using the ImageTool 3.0 software. Data, from each adhesive, were analyzed by two-way ANOVA and Tukey’s test (α?=?0.05).

Results

OC and CS showed higher μTBS and lower nanoleakage in the IM period when applied with SV groups. For FB, no significant difference was observed between the two modes of application. All materials showed lower nanoleakage in the SV groups. Higher nanoleakage was observed after 6M for OC and FB.

Conclusions

The sonic application mode at an oscillating frequency of 170 Hz can improve the resin–dentin μTBS, reduce the nanoleakage, and retard the degradation of the resin–dentin μTBS of Clearfil S³ Bond and One Coat 7.0 adhesives.

Clinical significance

Sonic application mode at an oscillating frequency of 170 Hz can be helpful and easy to use in dental practice to guaranty long-lasting restorations.     

Children's toothbrush contamination in day-care centers: how to solve this problem?

Objective

To evaluate the contamination level of toothbrushes by mutans streptococci (MS) and the efficacy of antimicrobial solutions: cetylpyridinium chloride 0.05 % (CPC; Cepacol?) and chlorhexidine 0.12 % (CHX; Periogard?), to disinfect toothbrushes of preschool-aged children in day-care centers.

Material and methods

Fifty-two children were randomly divided into three groups, and a three-stage changeover system was used with a 1-week interval between each stage. Solutions were used by a different group of children in each stage. Children were submitted to a 1 minute brushing without dentifrice, performed by a professional calibrated, followed by random spraying over the bristles of brushes. Process and microbiological analysis were realized, and four brushes of each group were analyzed by scanning electron microscopy (SEM).

Results

Friedman's test at 5 % significance level revealed difference between the antimicrobial solutions (p?Conclusions The toothbrushes were contaminated with MS after a single brushing.

Clinical relevance

Although CPC has shown good results in comparison with the control, CHX showed greater efficacy in disinfection bristles of toothbrushes.     

Qualitative and quantitative evaluation of human dental enamel after bracket debonding: a noncontact three-dimensional optical profilometry analysis

Objectives

The aim of this study was to undertake a qualitative and quantitative evaluation of changes on enamel surfaces after debonding of brackets followed by finishing procedures, using a high-resolution three-dimensional optical profiler and to investigate the accuracy of the technique.

Materials and methods

The labial surfaces of 36 extracted upper central incisors were examined. Before bonding, the enamel surfaces were subjected to profilometry, recording four amplitude parameters. Brackets were then bonded using two types of light-cured orthodontic adhesive: composite resin and resin-modified glass ionomer cement. Finishing was performed by three different methods: pumice on a rubber cup, fine and ultrafine aluminum oxide discs, and microfine diamond cups followed by silicon carbide brushes. The samples were subsequently re-analyzed by profilometry.

Results

Wilcoxon signed-rank test, Kruskal–Wallis test (p?U test with Bonferroni correction (p?Conclusions The 3D optical profilometry technique was able to provide accurate qualitative and quantitative assessment of changes on the enamel surface after debonding.

Clinical relevance

Morphological changes in the topography of dental surfaces, especially if related to enamel loss and roughness, are of considerable clinical importance. The quantitative evaluation method used herein enables a more comprehensive understanding of the effects of orthodontic bonding on teeth.     

Evaluation of a preventive program aiming at children with increased caries risk using ICDAS II criteria

Objectives

A selective intensified prevention (SIP) was introduced at individual schools in deprived areas in Marburg County (Germany) in 1995. The outcome of the program was evaluated in sixth graders (mean age: 12.06 years) in comparison to a control region.

Materials and methods

Caries experience was recorded by applying International Caries Detection and Assessment System (ICDAS) II criteria. Tooth brushing habits and other independent variables were examined psychometrically. To compare the mean caries scores, non parametric tests were applied. The influence of various independent variables on caries experience was assessed by stepwise backward logistic regression analysis. The matching criteria age, gender, ethnicity and maternal education were used to parallelize the samples.

Results

ICDAS scores of 2–6 were detected uniformly more often in the control region than in the test group. Combining ICDAS scores 3–6, children from the control region (mean D_3–6MFT: 1.73) showed roughly double the caries experience compared to the test group (mean D_3–6MFT: 0.88, p?<?0.005). The D_5,6MFT score of the test group amounted to 0.50, and the corresponding value of the reference group was 0.77 (p?=?0.043). Multivariate analysis disclosed fissure sealants, early start of tooth brushing and topical fluoride application to be associated with the prevention of dental caries. High frequency of sugar intake was associated with the presence of dentine lesions.

Conclusions

The results of our study confirm the positive effect of SIP on the dental health of 12-year-old pupils living in deprived areas.

Clinical relevance

On the basis of ICDAS II, targeted preventive measures can be applied in children with increased caries risk. Frequent applications of fluoride varnish inhibit the progression of initial lesions in this group.     

Manual versus rotary instrumentation for primary molar pulpectomies- A 24 months randomized clinical trial

Objective

The study compared manual and rotary canal instrumentation differences in primary molars receiving pulpectomy and their effect on clinical success after two years.

Laboratory evaluation of toothbrush/toothpaste abrasion resistance after smooth enamel surface sealing

Objectives

The use of dental sealants has been extended to smooth enamel surfaces. The present study was conducted to test the in vitro performance of four sealants with different characteristics (highly and lowly filled, self-etching features).

Materials and methods

Eighty human teeth (lower incisors and premolars) were randomly divided into following sealant test groups: ProSeal^TM, LightBond^TM, OrthoSolo^TM, and Seal&Protect^®. Twenty untreated teeth served as a control group. Tooth brushing was conducted for a period of time simulating 12, 18, and 24 months. During the toothbrush abrasion protocol, the specimens were subjected to thermal and acidic challenge. Sealant thickness was determined with μCT imaging, and qualitative and quantitative surface effects were investigated using stereo microscopy and raster electron microscopy, respectively. Data were subjected to t test or Kruskal–Wallis/Mann–Whitney tests (alpha, 5 %).

Results

The wear behavior and film integrity of highly filled sealants were superior to lowly filled sealants. Even after 1 year of tooth brushing, significant surface deterioration with deleterious loss of enamel and discoloration was observed in all tested materials (χ²?=?15.349; P?=?0.004). The size of the observed defects increased over time.

Conclusion

These results suggest that the application of sealants on smooth enamel surfaces should be limited to special indications, and their usefulness has to be revisited.

Clinical relevance

Based on the results of this in vitro study, the general overall application of enamel sealants needs to be questioned.     

Saliva fluoride before and during 3 years of supervised use of fluoride toothpaste

Objectives

The purpose of the study was to examine pre-brushing saliva fluoride concentrations before and during a large, 3-year, prospective toothpaste study on the effect of post-brushing rinsing on dental caries. The aims were to study saliva fluoride over time and the effect of rinsing on saliva fluoride and to relate saliva fluoride to caries increments and accumulation of plaque.

Materials and methods

Saliva samples (baseline and 1, 2, and 3 years) were collected from 11-year-old children attending two schools (A and B) in Kaunas, Lithuania, who refrained from brushing the evening and morning before saliva collection. Numbers of saliva samples collected varied from 264 at baseline to 188 at the 3-year follow-up. Children in school A rinsed with water after daily brushing, while children in school B did not rinse. Total caries and visible plaque were registered at baseline and after 3 years.

Results

Mean saliva fluoride concentrations at baseline and after 1, 2, and 3 years from school A (rinsing) were 0.014, 0.026, 0.029, and 0.034 ppm and from school B (no rinsing) were 0.013, 0.028, 0.031, and 0.031 ppm, respectively. Increases in saliva fluoride from baseline were significant (Wilcoxon’s test, p?<?0.001), but the increase from baseline to year 1 was not statistically significantly different between schools. Saliva fluoride did not increase beyond year 1 and did at no time point differ between schools. Reductions in numbers of tooth surfaces with dental plaque were significantly positively related to the number of caries reversals over the 3 years.

Conclusions

Background saliva fluoride concentration is increased by brushing at least once daily on schooldays, does not increase further over 3 years, and is not affected by rinsing after brushing.

Clinical relevance

Continuous use of fluoride toothpaste produces ambient saliva fluoride levels similar to saliva fluoride in areas with fluoridated water.     

Oral health-related quality of life of paediatric patients with AIDS

Background

Information bias can occur in epidemiological studies and compromise scientific outcomes, especially when evaluating information given by a patient regarding their own health. The oral habits of children reported by their mothers are commonly used to evaluate tooth brushing practices and to estimate fluoride intake by children. The aim of the present study was to compare observed tooth-brushing habits of young children using fluoridated toothpaste with those reported by mothers.

Methods

A sample of 201 mothers and their children (aged 24-48 months) from Montes Claros, Brazil, took part in a cross-sectional study. At day-care centres, the mothers answered a self-administered questionnaire on their child's tooth-brushing habits. The structured questionnaire had six items with two to three possible answers. An appointment was then made with each mother/child pair at day-care centres. The participants were asked to demonstrate the tooth-brushing practice as usually performed at home. A trained examiner observed and documented the procedure. Observed tooth brushing and that reported by mothers were compared for overall agreement using Cohen's Kappa coefficient and the McNemar test.

Results

Cohen's Kappa values comparing mothers' reports and tooth brushing observed by the examiner ranged from poor-to-good (0.00-0.75). There were statistically significant differences between observed tooth brushing habits and those reported by mothers (p < 0.001). When observed by the examiner, the frequencies of dentifrice dispersed on all bristles (35.9%), children who brushed their teeth alone (33.8%) and those who did not rinse their mouths during brushing (42.0%) were higher than those reported by the mothers (12.1%, 18.9% and 6.5%, respectively; p < 0.001).

Conclusions

In general, there was low agreement between observed tooth brushing and mothers' reports. Moreover, the different methods of estimation resulted in differences in the frequencies of tooth brushing habits, indicative of reporting bias. Data regarding children's tooth-brushing habits as reported by mothers should be considered with caution in epidemiological surveys on fluoridated dentifrice use and the risk of dental fluorosis.     

Oval-shaped canal retreatment with self-adjusting file: a micro-computed tomography study

Objectives

The aim of this study was to assess the efficacy of removing the filling material from oval-shaped canals with rotary retreatment files, with or without the additional use of self-adjusting file (SAF), using micro-computed tomography.

Materials and methods

Oval-shaped canals from 20 maxillary premolars were prepared and assigned to two groups (n?=?10), according to the obturation technique: cold lateral condensation (CLC) or vertical condensation (VC). Then, retreatment procedure was performed with retreatment rotary instruments followed by SAF. The specimens were scanned after each procedure and the volume of the filling material calculated. Median and interquartile range (IQR) percentages of the remaining filling material after each retreatment technique were statistically compared by Wilcoxon and Mann–Whitney U tests with a significance level of 5 %.

Results

The median percentage volume of the filling residue after rotary retreatment procedure was 1.59 (IQR?=?1.26) and 0.42 (IQR?=?0.86) in the CLC and VC groups, respectively (p?<?0.05). After the use of SAF, the median percentage was 1.26 (IQR?=?0.75) and 0.12 (IQR?=?0.53) in the CLC and VC groups, respectively (p?<?0.05). Statistically significant difference was also observed within the group after the additional use of SAF (p?<?0.05).

Conclusions

None of the retreatment procedures completely removed the filling material. The additional use of the SAF improved the removal of filling material after the retreatment procedure with rotary instruments.

Clinical relevance

Filling material left after retreatment procedure may harbour necrotic tissue and bacteria, which could lead to a persistent disease and reinfection of the root canal system. The additional use of self-adjusting file after the conventional retreatment procedures may improve root canal cleanliness, allowing a better action of the irrigating solution.     

Roughness of enamel surfaces after different bonding and debonding procedures

Background and Aim

Maintaining an intact enamel surface is an essential aspect of orthodontic therapy; however, various therapeutic measures can affect this surface. The aim of our study was to evaluate roughness of the enamel surface after different conditioning and polishing procedures.

Materials and Methods

42 bovine incisors were submitted to conventional abrasion (using 37% phosphoric acid), to air abrasion, and a combination of the two. Brackets were put in place and then debonded, and the remaining adhesive removed with a carbide bur or via air abrasion. The enamel surface??s roughness was assessed using a confocal laser scanning microscope (CLSM).

Results

Mean roughness (R_a) was 33.1. There were no statistically significant differences among the six groups, or in R_q values. Under CLSM, the roughness after polishing via air abrasion appeared even. Although it was macroscopically smoother after polishing with a carbide bur, the surface showed a wave-like pattern.

Conclusion

The method of enamel conditioning revealed no significant effect on the enamel surface after debonding. Neither polishing via air abrasion nor carbide bur resulted in differences in superficial roughness. However, the carbide bur left a wave-like pattern on the enamel surface.     

IN VITRO EVALUATION OF ROOT CANAL PREPARATION USING OSCILLATORY AND ROTARY SYSTEMS IN FLATTENED ROOT CANALS

Objective:

The aim of this study was to evaluate the biomechanical preparation of flattened root canals using the following systems: Endo-Eze AET stainless steel oscillatory instruments (Ultradent) and RaCe rotary NiTi instruments (FKG Dentaire).

Materials and Methods:

Twenty extracted human mandibular incisors were randomly assigned to two groups: Group 1 - Instrumentation with oscillatory Endo-Eze AET files (oscillatory technique); Group 2 - Instrumentation with rotary NiTi RaCe files (rotary technique). The teeth were decoronated, had their apices and coronal openingssealed with sticky wax and were embedded in crystal-clear orthophtalic polyester resin. The roots were sectioned transversally with diamond discs at 10 mm (middle third) and 5 mm (apical third) from the apex and the segments were reassembled for instrumentation. The sections were photographed before and after root canal instrumentation and evaluated with respect to whether the original root canal shape was modified by instrumentation. To evaluate the differences in the root canal shape before and after biomechanical preparation, scores were given regarding the instruments touch on the intracanal walls.

Results:

In middle third of the root canals instrumented with the rotary system, there was a change in the original canal anatomy (p<0.05), with formation of a protuberance in the mesiodistal direction. This protuberance did not occur when the oscillatory instrumentation was used. The oscillatory system had better results in the middle and apical thirds as evaluated by Dunn’s multiple-comparison test (p>0.05).

Conclusion:

Under the tested conditions, Endo-Eze oscillatory system yielded the instrumentation of all flattened root canal walls, maintaining the canal original shape throughout the biomechanical preparation, and was more effective than RaCe rotary system.     

One- and 3-minute plaque removal by a battery-powered versus a manual toothbrush

BACKGROUND: A new battery-powered toothbrush with a fundamentally different design than other powered toothbrushes has recently been introduced. The new toothbrush has a powered oscillating round head and a second powered head that translates back and forth. This study compared the plaque removal efficacy of a manual toothbrush to this new powered toothbrush. METHODS: This randomized, controlled, examiner-masked, four-period cross-over study examined plaque removal with the two toothbrushes following a single use in 40 subjects. Plaque was scored before brushing and after 1 and 3 minutes of brushing using the Turesky modification of the Quigley-Hein index. RESULTS: Baseline plaque scores were 2.98 prior to using the powered toothbrush and 2.99 prior to using the manual toothbrush. The powered toothbrush delivered a covariance-adjusted mean plaque score change from baseline of 0.61 after 1 minute of brushing and 0.93 after 3 minutes of brushing. The adjusted mean changes for the manual toothbrush were 0.43 and 0.62, respectively. The differences between treatment groups were statistically significant (P < 0.001) after both 1 and 3 minutes of brushing. The powered toothbrush had, on average, 42.1% and 49.6% greater plaque removal scores after 1 minute and 3 minutes of brushing, respectively. Both toothbrushes had statistically significantly greater plaque removal scores after 3 minutes than after 1 minute of brushing (P < 0.001). Plaque removal scores for each toothbrush after 3 minutes of brushing were about 50% higher than the scores after 1 minute of brushing. CONCLUSIONS: The powered toothbrush delivered statistically significantly superior plaque removal after both 1 and 3 minutes of brushing compared to the manual toothbrush. Both toothbrushes showed statistically significantly greater plaque removal following 3 minutes of brushing than following 1 minute of brushing, and the difference between the toothbrushes was greater following 3 minutes of brushing than following 1 minute of brushing.     

Relationship between plaque score and video-monitored brushing performance after repeated instruction—a controlled, randomised clinical trial

Objectives

Aim of this prospective, randomised, controlled clinical trial was to use the modified bass technique (MBT) and a specific brushing sequence to investigate whether two types of instruction methods lead to differences in plaque reduction and whether plaque reduction is related to technique adoption.

Methods

Ninety-eight participants were randomly assigned to three groups: (1) control, no instruction; (2) verbal instruction by means of a leaflet; and (3) verbal instruction supported by demonstration, no leaflet. Brushing performance was video monitored. Plaque score (Turesky modified QHI (T-QHI)) was measured at baseline, afterwards participants received instructions. After 2 weeks, T-QHI was measured for a second time, and participants were re-instructed. After another 2 weeks, T-QHI was measured for a third time.

Results

At baseline, T-QHI did not differ between groups ((1) 1.99?±?0.51, (2) 1.90?±?0.51, (3) 1.93?±?0.56). The second measurement revealed an improvement of T-QHI in the instructed groups and in the non-instructed control group ((1) 1.80?±?0.47, (2) 1.58?±?0.58, (3) 1.64?±?0.58; n.s. between groups); in the intervention groups, remotivation achieved no further improvement ((1) 1.72?±?0.48, (2) 1.52?±?0.58, (3) 1.50?±?0.69; n.s. between groups and compared to second measurement). Improvement of T-QHI was not related to proper performance of technique or brushing sequence. Those who fully adopted the brushing technique, the sequence or both did not have lower plaque scores.

Conclusion

Technical performance and effectiveness were not linked.

Clinical relevance

Within the study setting, the MBT was not effective in reducing plaque scores. The general recommendation of the MBT should be re-evaluated in further studies.