In vitro effect of the Sensonic toothbrush on Treponema denticola

Safety and Design Aspects of Powered Toothbrush-A Narrative Review

The powered toothbrush has become a modern dental tool that is available in the supermarket. Indeed, the design of the powered toothbrush, e.g., mechanical and electrical, would affect not only the efficacy but also the safety of the products. This narrative review attempted to view the powered toothbrush from design, safety, and application points with respect to tufts, filaments, handles, mechanics, motions, and materials interactions from various available sources. Different brands and models of powered toothbrushes have their own designs that might affect the clinical outcome. The rotational design was advocated to be clinically more effective than the manual one, some modern models might be designed with vibrational or oscillation (or mixed) tufts head that might be useful in patients with specific needs, such as having xerostomia or for the elderly. To conclude, tuft retention design is important in the powered toothbrush as it contributes significantly to safety as the fallen off tufts, filaments and metal parts might cause injury. Tests revealing the retention force of brush head plates and brush head bristles will be significant references for consumers to determine which design of powered toothbrushes is relatively safer.

Viscoelasticity of biofilms and their recalcitrance to mechanical and chemical challenges

We summarize different studies describing mechanisms through which bacteria in a biofilm mode of growth resist mechanical and chemical challenges. Acknowledging previous microscopic work describing voids and channels in biofilms that govern a biofilms response to such challenges, we advocate a more quantitative approach that builds on the relation between structure and composition of materials with their viscoelastic properties. Biofilms possess features of both viscoelastic solids and liquids, like skin or blood, and stress relaxation of biofilms has been found to be a corollary of their structure and composition, including the EPS matrix and bacterial interactions. Review of the literature on viscoelastic properties of biofilms in ancient and modern environments as well as of infectious biofilms reveals that the viscoelastic properties of a biofilm relate with antimicrobial penetration in a biofilm. In addition, also the removal of biofilm from surfaces appears governed by the viscoelasticity of a biofilm. Herewith, it is established that the viscoelasticity of biofilms, as a corollary of structure and composition, performs a role in their protection against mechanical and chemical challenges. Pathways are discussed to make biofilms more susceptible to antimicrobials by intervening with their viscoelasticity, as a quantifiable expression of their structure and composition.

Recalcitrance of biofilms against mechanical and chemical challenges has been looked at for ages from a microbiological perspective, but an approach based on viscoelastic properties of biofilms yields new insights in this recalcitrance.

Does cavitation occur around powered toothbrushes?

AIMS/OBJECTIVES

The aim of this investigation was to determine if cavitational activity occurred around powered toothbrushes using a chemical dosimeter system based on terephthalic acid (TA).

MATERIAL AND METHODS

Five powered toothbrushes were used in this investigation: Braun Plaque Remover D8, Braun Oral-B 3D, Philips Jordan Sensiflex HX2520, Sonicare PS-1 and Sonicare Elite HX 7351/02. Each brush head was inserted into a conical flask containing 50 cm3 of aqueous TA solution. Brushes were operated for 10 and 20 min and a cuvette of the solution was placed in a fluorescence spectrometer (Perkin Elmer 3000). The fluorescence emitted at wavelength 425 nm, which is proportional to *OH radical concentration, was monitored.

RESULTS

Any cavitational activity that may have been produced by the powered toothbrushes was below the limit of detection of the system (<10(-8) M) for the timescales investigated.

CONCLUSIONS

This work has demonstrated that cavitational activity does not occur around powered toothbrushes. Operating the toothbrushes for periods up to 20 min resulted in no cavitational activity being detected.

A comparison of the efficacy of 2 powered toothbrushes in affecting plaque accumulation, gingivitis, and gingival bleeding

BACKGROUND

The purpose of this 30-day blinded, parallel-design study was to compare the effect of 2 powered toothbrushes, the Rowenta MH700 and the Braun Plak Control Ultra, on reducing plaque accumulation, gingivitis, and gingival bleeding in a cohort of 60 healthy adults.

METHODS

After baseline evaluation of plaque, gingivitis, and gingival bleeding, subjects were randomly assigned to one of the experimental groups, provided written and verbal toothbrushing instructions, and had their teeth polished. At 2 weeks (follow-up 1) and 4 weeks (follow-up 2), all clinical parameters were again evaluated.

RESULTS

The Braun group demonstrated a nearly significant reduction in gingival index (GI) and a significant reduction in GI at follow-up 2. The Rowenta group demonstrated significant reductions in GI, plaque index (PI), and bleeding index (GBI) at both follow-up 1 and 2 examinations. At follow-up 1, the Braun group demonstrated a nearly significant reduction in GI, a significant reduction in PI, and a non-significant reduction in GBI. At follow-up 2, the Braun group demonstrated a significant reduction in GBI, but not a significant reduction in PI. The reduction in GI for the Rowenta group was significantly greater (P values of 0.0001 and 0.0001, respectively) than that demonstrated in the Braun group. However, the Rowenta group did not demonstrate a significantly greater reduction in PI (P values of 0.7135 and 0.3184 for follow-up 1 and follow-up 2, respectively) or GBI than the Braun group at either examination (P values of 0.0663 and 0.3397 for follow-up 1 and 2, respectively).

CONCLUSIONS

The results of this study support the findings of numerous other studies that powered toothbrushes have great potential to remove plaque and improve gingival health and that the improvement can be demonstrated in a relatively short period of time.

Sonic and mechanical toothbrushes. An in vitro study showing altered microbial surface structures but lack of effect on viability

The purpose of the present study was to compare the in vitro effects of a mechanical and a sonic toothbrush on the viability of Actinomyces viscosus, the rationale being that induction of irreparable microbial damage resulting from aggressive mechanical action or sonic energy, may inhibit or disrupt the process of successional colonization. Cultures of A. viscosus were grown to a standardized optical density and subdivided into 3 treatment groups of 20 specimens each. Treatment groups consisted of an untreated control and exposure to a mechanical or sonic toothbrush for 15, 30, 45, and 60 s. Subsequent to the prescribed treatment, samples were taken from each specimen dish, subcultured, and the number of CFUs determined. Additional samples were obtained for negative staining and examination by electron microscopy. The mean number of CFUs for each treatment group at each treatment interval were statistically analyzed by ANOVA and multiple pairwise comparisons. Results showed a significant main effect for toothbrushes (p<0.0001) and exposure time (p<0.01), but only marginal significance for the interaction of toothbrush with exposure time (p<0.055). Post-hoc tests showed a significantly greater number of CFUs for the sonic toothbrush compared to both the untreated control and mechanical toothbrush groups. Electron microscopic examination revealed a decrease in aggregation tendency and loss of fimbriae in the sonic toothbrush group. Based on the lack of morphologic evidence that would indicate cell damage and the increase in CFUs over that of the control group, it appeared that neither the mechanical or sonic toothbrushes affected cell viability.