Preclinical evaluation of a new synthetic carbonate apatite bone substitute on periodontal regeneration in intrabony defects

Abstract

Objective: To evaluate the potential of a novel synthetic carbonate apatite bone substitute (CO₃ Ap-BS) on periodontal regeneration.

Background: The use of various synthetic bone substitutes as a monotherapy for periodontal regeneration mainly results in a reparative healing pattern. Since xenografts or allografts are not always accepted by patients for various reasons, a synthetic alternative would be desirable.

Methods: Acute-type 3-wall intrabony defects were surgically created in 4 female beagle dogs. Defects were randomly allocated and filled with CO₃ Ap-BS (test) and deproteinized bovine bone mineral (DBBM) or left empty (control). After 8 weeks, the retrieved specimens were scanned by micro-CT, and the percentages of new bone, bone substitute, and soft tissues were evaluated. Thereafter, the tissues were histologically and histometrically analyzed.

Results: Healing was uneventful in all animals, and defects were present without any signs of adverse events. Formation of periodontal ligament and cementum occurred to varying extent in all groups without statistically significant differences between the groups. Residues of both bone substitutes were still present and showed integration into new bone. Histometry and micro-CT revealed that the total mineralized area or volume was higher with the use of CO₃ Ap-BS compared to control (66.06 ± 9.34%, 36.11 ± 6.40%; p = .014, or 69.74 ± 2.95%, 42.68 ± 8.68%; p = .014). The percentage of bone substitute surface covered by new bone was higher for CO₃ Ap-BS (47.22 ± 3.96%) than for DBBM (16.69 ± 5.66, p = .114).

Conclusions: CO₃ Ap-BS and DBBM demonstrated similar effects on periodontal regeneration. However, away from the root surface, more new bone, total mineralized area/volume, and higher osteoconductivity were observed for the CO₃ Ap-BS group compared to the DBBM group. These findings point to the potential of CO₃ Ap-BS for periodontal and bone regeneration.

Keywords: biomaterial; bone regeneration; histology; intrabony defect; micro-CT; periodontal regeneration.