Dentin Substrate Wear of Powered Toothbrushes Using an in vitro Ridged-configuration Model

Objectives: To measure wear of dentin caused by powered toothbrushes using an in vitro model which simulates the prominences of teeth in order to match the clinical situation more closely. Methods: Dentin slices with a surface area of 3 x 10 mm were embedded in temporary C & B material. The shape of the specimen consisted of a central ridge containing the dentin slice and 2 lateral half-round composite ridges (radius = 3 mm). The specimens were brushed with 12500 strokes of a linear motion (35 mm amplitude) and standardized toothbrush slurry. Brushing was done either with a manual toothbrush (ADA control brush) or the powered toothbrushes Braun Oral-B D17 or Sonicare Elite at 90 g or 150 g loads (N=12 per group). Dentin substrate loss was measured with a 3D-laserscanner. Differences were statistically evaluated with a oneway-analysis of variance and Tukey post-hoc test. Results: The dentin wear results are: mean [µm](SD [µm]). Homogenous subsets are identified with the same coefficients (a, b, c or d): Philips Sonicare Elite 90g: 21 (29) {a} < Philips Sonicare Elite 150g: 44 (20) {a, b} < OralB-D17 90g: 66 (26) {b, c} < ADA Control 90g: 69 (22) {b, c, d} < ADA Control 150g: 84 (20) {c, d} < OralB-D17 150g: 95 (24) {d}< ADA Control 250g: 107 (36) {d}. The wear increases with increasing load. The Sonicare Elite caused the lowest wear. The OralB-D17 h was not significantly different from the wear of the manual toothbrush. Conclusions: None of the powered toothbrushes had higher dentin wear compared to the ADA control toothbrush. Sonicare Elite had less wear than the OralB-D17 powered tooth brush. However, these experiments on wear evaluation have to be complemented by experiments to evaluate cleaning efficacy.