Site-Specific Nanoindentation Hardness of Human Root Cementum and Corresponding Alveolar Cortical Bone: Associations with Uncalibrated CBCT and Micro-CT Gray-Value Indices

Background/Objectives: The local mechanical properties of periodontal supporting tissues influence their responses to orthodontic forces. This exploratory study sought to evaluate site-specific nanoindentation hardness in human root cementum and adjacent alveolar cortical bone and examine its association with cone-beam computed tomography (CBCT)- and micro-computed tomography (micro-CT)-derived relative imaging indices.

Methods

Specimens from seven human cadavers were analyzed. Indentation hardness (HIT) was measured in the central and apical regions of root cementum and adjacent alveolar cortical bone. CBCT gray values and micro-CT-derived relative imaging indices were obtained from anatomically matched regions without phantom-based mineral-density calibration. Nonparametric tests, multiple linear regression analyses, and Spearman's rank correlation analyses were performed.