# Optical Coherence Tomography, Stereomicroscopic, and Histological Aspects of Bone Regeneration on Rat Calvaria in the Presence of Bovine Xenograft or Titanium-Reinforced Hydroxyapatite

## TL;DR

This study compares how well a synthetic biomaterial and a bovine xenograft support bone healing in rats, finding the xenograft performs better.

## Contribution

The study introduces a comparative analysis of a titanium-reinforced hydroxyapatite biomaterial and bovine xenograft in rat calvaria bone regeneration.

## Key findings

- Bovine xenograft showed better tissue response and integration into bone compared to the synthetic biomaterial.
- Both biomaterials supported bone healing but showed limited integration within the study period.
- OCT, stereomicroscopy, and histology confirmed similar healing patterns across the groups.

## Abstract

Background: Alveolar ridge preservation (ARP) techniques have evolved with implantology development. In clinical practice, biomaterials for ARP are tested in laboratory animals, and rat calvaria is a standard option. The study aimed to evaluate biomaterial osteointegration in defects created in the rat calvaria, comparing an experimental synthetic biomaterial with a bovine xenograft and natural healing. Methods: The study included six groups of animals: two negative control groups with natural healing (2 months (M) and 4 M), two positive control groups with bovine xenograft (2 M and 4 M), and two study groups with nanohydroxyapatite titanium reinforced (2M and 4M). After creating and grafting the defects, healing was expected to take 2 or 4 months, after which bone fragments were harvested, prepared, and then analyzed. OCT, stereomicroscopy, and histology techniques were used for bone fragments analysis, and the obtained images were evaluated using Image J 1.54p software. Results: The results obtained from the three analyses provided information about the healing pattern of bone defects and the degree of new bone formation. Histological analysis of the samples confirmed what the stereomicroscopy and OCT images showed: that the bovine xenograft elicited a better tissue response than the synthetic biomaterial, being incorporated into the bone tissue more than the synthetic biomaterial. Conclusions: Both the bovine xenograft and the synthetic nanocomposite based on hydroxyapatite reinforced with titanium particles favored bone healing, but their integration into the bone was limited for the analyzed period.