Methods: Nine interdental brushes of diameters ranging from 2.5mm to 8.0mm were tested on aluminum blocks, painted black and covered with a titanium oxide slurry. This slurry was reapplied and dried before each of 4 repetitions of a single horizontal movement at fixed separations of 1mm, 2mm and 3mm for each brush tested. A glide path of 1cm penetration was standardized by fixing the interproximal brushes in a holder mounted on a track which slid the brushes into the space between the fixed opposing parallel surfaces. All the brushes tested moved freely at each interval. The resulting gray-scale pattern was scanned into a computer for planimetric analysis of the slurry removed. The percentage was then adjusted to represent a ratio to the maximal cleaning potential (diameter x 10mm) of each individual brush and thereby provide the relative cleaning efficacy. The data was analysed using ANOVA with Bonferroni/Dunn correction (p<0.05).
Results: The relative cleaning efficacy of the 9 brushes ranged from 94% for a brush of 2.5mm diameter to 42% for a 5mm brush in a 1mm space. In the 2mm space, the relative cleaning efficacy ranged from 59% for a 3mm brush to 28% for an 8mm brush. At 3mm distance, irrespective of diameter, the relative efficacy ranged from 29% to 15%.
Conclusions: Within the limitations of the present study, smaller brushes cleaned more efficiently than larger brushes. The larger the approximal distance, the less efficient any size brush cleaned.
No outside funding was used for his study.