A novel method to quantify dentine tubule occlusion applied to in situ model samples.

Objectives: To develop an innovative computerised routine, in conjunction with a minimally destructive imaging technique, to quantify dentine tubule occlusion.

Methods: Polished human dentine samples (n = 480) were brushed during a 4-day in situ study with two occlusion-based dentifrices, a sodium fluoride control dentifrice (1,450 ppm) or water. Samples were imaged with tandem scanning microscopy (TSM) and conventional scanning electron microscopy (SEM). The level of dentine patency was then assessed using a visual ordinal scale ('standard') or quantitatively using a specially designed computational routine.

Results: The occlusion-based dentifrice resulted in significantly less patent dentine than controls for the 'standard' (p = 0.01) assessment, but not for computer analyses (p = 0.10). The correlation of the number of individual patent tubules counted visually and by the computational routine in calibrations and in the in situ study was ≥ 0.8.

Conclusions: This study identified a new computer-based routine, capable of objectively quantifying the patency of dentine imaged by SEM and TSM.