Plaque removal characteristics of electric toothbrushes using an in vitro plaque model

Background/aim: The purpose of the study was to investigate and quantify th e efficacy of plaque removal by commercially available electric toothbrushe s using an in vitro system based on artificial plaque grown on glass slides . Material and Methods: Artificial plaque based on Streptococcus sanguis and Streptococcus mutans was cultured in a series of phosphate buffer solution, sucrose solution and brain heart infusion on sterile glass slides, for a p eriod of 5 weeks. 7 different electric toothbrushes of current designs were operated in contact ;with the glass slides under loads of 1 or 2N for 10 s after which image analysis of the brushed slides was undertaken to calcula te the absolute and relative areas of removal. Results: The electric toothbrushes showed a larger area of plaque removal a s loading force increased from 1 to 2N. The area of biofilm. removed also d epended on the head design and ranged from 258 mm(2) (1N, Interplak) and 31 4 mm(2) (2N, Interplak), to 30 mm(2) (1N, Braun 3D), and 148 mm(2) (2N, Ble nd-a-Dent). The area of biofilm removal was significantly different among a ll electric toothbrushes at p <0.01 (ANOVA). All electric toothbrushes remo ved more biofilm than the actual contacting tufted area of the head. Conclusion: The artificial plaque model system under different loading cond itions showed differences in the absolute area of removal per electric toot hbrush and also differences in the relative removal per unit contact bristl e area. These differences on operating variables should be considered when evaluating new electric toothbrushes.