The effects of prophylactic polishing pastes on dentine tubular occlusion

Objectives: To investigate the in vitro effectiveness of six selected prophylactic pastes on dentine tubule occlusion, namely three experimental polishing pastes containing 45S5, 45S5P6, and 45S5P6F5 bioglass, Nupro® Sensodyne® ([NS]DENTSPLY International), with/without fluoride, and a base paste containing no bioglass.
Methods: Three bioactive glasses were made as follows 1) high phosphate (45S5P6) 2) with fluoride (45S5P6F5) and 3) the basic bioactive glass (45S5). Preparation of the dentine discs (200-400 microns thick) was by sectioning mid-coronal portions of extracted teeth. A modified Pashley Hydraulic Conductance device was used to measure the fluid flow rates through the dentine discs. The fluid flow rates were measured before and after applying the prophylactic pastes, reduction in fluid flow would indicate that tubular occlusion had occurred.

Results: There was a significant reduction of the fluid flow rates of 55.4% for NS with fluoride, and 53.6% for NS without fluoride. The experimental prophylactic pastes gave a fluid flow reduction range of 41.26-56.9%. However, there were no statistical differences between the NS products +/- fluoride. The base paste used to formulate the experimental bioglass pastes also gave a significant reduction in fluid flow of 40.41%, however there were no statistical significant differences observed when adding the bioactive glasses to the base paste. This may suggest that silica particles in the base paste were also effective in reducing fluid flow rates. The three experimental pastes had a similar tubular occlusion effect. Paired T tests demonstrated no significant differences between the prophylactic pastes.

Conclusions: Conclusion: All the prophylactic polishing pastes were effective in reducing fluid flow through tubular occlusion as the pastes contained both the bioactive glass and silica particles with smaller diameter than the dentine tubule diameter. The results from the NS +/- fluoride pastes would suggest that the fluoride content in the pastes has no effect on fluid flow rates.