An in vitro investigation of the abrasive qualities of a selection of denture-cleaning pastes on poly(methyl methacrylate) denture base material.

This study investigated the damage to poly(methyl methacrylate) (PMMA) denture base material caused by brushing with a range of denture-cleaning pastes using an electric, motor-driven, reciprocal-action toothbrushing machine. Plate specimens of PMMA were exposed to 5000, 10,000 and 20,000 brush strokes with four commercial and one recently developed denture-cleaning pastes. Products were applied as slurries in dilutions of 1:2, 1:3 and 1:5. Wear and roughness measurements were made using a surfometer. Results of a one-way analysis of variance showed that there was a statistically significant difference between each of the different denture-cleaning pastes at each given dilution for each number of wear cycles. For the denture-cleaning pastes, doubling the number of brush strokes in most cases, increased the depth of abrasion by a factor of two. A reduction in the Roughness Index and depth of wear was seen, again in most cases, with a dilution from 1:2, 1:3 and to 1:5. A recently developed paste (Blend-a-Dent Hygienic denture paste) bad a comparatively low wear and roughening effect on PMMA denture base material; however, further investigation of its stain-removal properties are necessary before it can be recommended as a suitable denture-cleaning paste.