Experimental analysis of three different toothbrushes for interproximal space cleaning: in vitro and clinical evaluation

Aim: the objective of this in vitro study is to evaluate the effectiveness of the removal of interdental plaque with three different toothbrushes: a manual one, one with oscillating-rotating movements and a sonic one. Methods: 6 extracted human teeth were fixed in a plaster socket and matched to pairs simulating interdental spaces of three different sizes: a small one of 2.71 mm in length by 2.55 mm in height, an average one of 3.69 mm in length by 3.24 mm in height, and a great one of 4.26 mm in length by 4.07 mm in height. The approximal surfaces were covered by a layer of a commercial blue indicator, frequently used in dental laboratory ( Blue Marker,YETI Dentalprodukte GmbH), to simulate the interdental plaque and by a film of artificial saliva ( sodium phosphate dehydrate 1,07 g/L; calciumchloride dehydrate 0,22 g/L; sodium bicarbonate 1,68 g/L; purified water 99,703 g/L) to simulate the typical oral cavity environment. Subsequently, the interproximal surfaces were exposed to different toothbrushes handled by a group of dentists and dental hygienists and another one composed by peolple not in the industry: the standard mode of sonic toothbrush “Philips Sonicare Flexcare Platinum HX9142/04”, the daily cleaning mode of oscillatingrotating “Oral-B Triumph 5000 D 34.575.5X” and the traditional Bass mode performed with manual toothbrush “Acquafresh Dynamic Flex” were so applied. The mentioned toothbrushes were used with the following timings: 20 seconds for each interproximal space, 10 seconds for the vestibular side and 10 seconds for the lingual surface. Before and after standardized cleaning of the proximal surfaces, the pre- and postbrushing situations were registered with a digital camera (Nikon D 5000single-lens: AF-S NIKKOR 18-105 mm 1:3-5.6 G ED). The obtained pictures of all the 180 tests carried out were cropped with a sofware (Glimp 2.0) to isolate them from the background and to convert them to black and white thanks to another software (ImageJ 1:49). This last was applied in order to calculate the percentage of black (still stained with dye) and the one of white (cleaned by the brushing). Results: according to Wilcoxon’s test, no significant difference was observed between the surfaces cleaned by the group of non-experts and those of the expert group (P-value=0.11). ANOVA and Bonferroni’s test denote statistically significant differences among the three groups of toothbrushes (P-value=0.01). As can be seen from the cleansed surface values, the manual toothbrush yields the worst results. It cleans on average only 26.03% (min 13.07%; max 41.07%), the Oral-B toothbrush the 47.20% (min 15.01%; max 71.87%) and the sonic one 70.9% (min 52.30%; max 81.94%). Conclusions: the result achieved by “Sonicare Flexcare Platinum” is almost triple compared to the manual toothbrush and almost double compared to “Oral-B Triumph 5000”. It was found that this is due to the hydrodinamic forces produced by sonic toothbrushes