OBJECTIVES: This in vitro study explored quantitative outcome measures as clinical indicators of simulated occlusal tooth wear progression .
METHODS: Ten sound, extracted human premolars were selected and submitted to occlusal tooth wear simulation in 0.5-mm steps (0/0.5/1.0/1.5 mm). At each step, enamel thickness on the buccal cusp tips was evaluated using cross-polarization optical coherence tomography (CP-OCT) and micro-computed tomography (µ-CT). The occlusal surface of each premolar was also scanned at each step using a 3D digital intraoral scanner, followed by morphological characterization using standard topography attributes (Slope, Relief, RFI, OPCr). Repeated measures ANOVA assessed differences in simulated wear levels for the µ-CT and CP-OCT data as well as the topography values . Correlations were also calculated between the µ-CT/CP-OCT and topography data
RESULTS: : Significant differences were observed for enamel thickness at each simulation wear stage, for both CP-OCT (p <0.001) and µ-CT (p <0.001), with good agreement between methods (intraclass correlation : 0.89). For topography analysis, as wear increased, the average Slope, RFI, and Relief values decreased, and average OPCr values increased, with more significant differences shown for Slope . Slope showed significant (p <0.05) positive correlations with CP-OCT. OPCr showed significant negative correlations with µ-CT, and CP-OCT (p <0.05). RFI and Relief were not correlated with either µ-CT or CP-OCT (p> 0.05).
CONCLUSIONS: Our findings suggest the potential of PS-OCT for measuring enamel thickness changes in the cusp tips of the occlusal surface . Similarly, conventional intraoral scanners can serve effectively for monitoring overall tooth wear when combined with dental topographic analyses of resultant point clouds.