Effects of Carbonate Apatite and Bone Mixture on Bone and Soft Tissue Integration in a Rat Implant Model

Abstract

Background: Achieving stable bone regeneration and soft tissue integration is critical for the success of dental implants, especially in patients with alveolar bone defects. Carbonate apatite (CO₃Ap), a synthetic bone substitute, has emerged as a promising alternative due to its excellent osteoconductivity and biocompatibility. However, CO₃Ap lacks osteoinductive capacity, which limits its effectiveness in promoting bone regeneration on its own.

Purpose: This study aimed to evaluate the effects of a CO₃Ap-autogenous bone (AB) mixture on bone regeneration and soft tissue integration in a rat maxillary implant model.

Materials and methods: Sixty rats underwent extraction of their maxillary molars, followed by titanium implant placement. The extraction sockets were filled with three different materials: CO₃Ap, AB, or a CO₃Ap-AB mixture. In vivo bone tissue and soft tissue evaluations were performed at specified time points. Additionally, in vitro experiments were conducted to assess the osteogenic differentiation of mesenchymal stem cells when exposed to the CO₃Ap-AB mixture.

Results: In vivo experiments showed that the CO₃Ap-AB mixture significantly enhanced bone volume and maintained high bone mineral density compared to CO3Ap and AB alone. Furthermore, the mixture promoted longer epithelial attachment, suggesting its potential for long-term soft tissue stabilization. In vitro, the CO₃Ap-AB mixture effectively promoted osteogenic differentiation of mesenchymal stem cells.

Conclusions: The combination of CO₃Ap and AB exhibited a synergistic effect, enhancing early bone regeneration, osseointegration, and soft tissue sealing, which are crucial for implant stability. The CO₃Ap-AB mixture shows great potential as a clinically effective bone substitute for dental implant treatment in patients with compromised bone conditions.

Keywords: autogenous bone; carbonate apatite; osseointegration; osteoinductivity; rat maxillary implant model; titanium dental implant.