Influence of osteoporosis on tissue repair promoted by different dental materials: an in vivo study in a rat model

Objectives: Osteoporosis is a prevalent metabolic disorder, and its impact on the biological response to dental materials is not fully understood. This study evaluated whether osteoporosis affects tissue repair promoted by MTA-Angelus (MTA) and an epoxy resin-based sealer containing calcium hydroxide (ER-Ca) after implantation in rat dental sockets. The null hypothesis was that osteoporosis would not impair alveolar tissue repair or bone formation. Methods: Seventy-two female rats were assigned to ovariectomized (OVX) or sham-operated (SHAM) groups (n = 36). After osteoporosis confirmation, right upper incisors were extracted, and polyethylene tubes containing MTA, ER-Ca, or left empty (control) were implanted in the sockets for 30 and 60 days (n = 6/group). Histology quantified inflammatory cells (ICs), fibroblasts (FBs), capsule thickness, and bone formation. Data were analyzed using Kruskal-Wallis and Dunn tests (p < 0.05). Results: At 30 days, the material groups showed high IC counts (50-75 and >75 cells/field), whereas the control groups exhibited lower inflammatory scores. By 60 days, ICs decreased, FB counts increased (25-50 and 50-75 cells/field), and connective tissue thickness reduced. The OVX groups exhibited higher IC counts than SHAM at both time points (p < 0.05). MTA and ER-Ca showed comparable repair patterns. Bone formation occurred in SHAM groups treated with MTA and ER-Ca at 30 days (62.3 and 63.4 μm), and in all treated groups at 60 days, except controls. Conclusions: Osteoporosis delays inflammation resolution and new bone formation during alveolar healing. However, MTA and ER-Ca demonstrate favorable biocompatibility, supporting their clinical use in osteoporotic conditions. Further research should focus on optimizing materials and adjuvant therapies to enhance bone regeneration under compromised conditions.