# Comparative in vivo evaluation of cross-linked and non-cross-linked collagen membranes for guided bone regeneration in rat calvarial defects

## TL;DR

This study compared cross-linked and non-cross-linked collagen membranes for bone regeneration in rats, finding that the cross-linked membrane promoted better bone growth over time.

## Contribution

The study provides new in vivo evidence that cross-linked collagen membranes outperform non-cross-linked ones in guided bone regeneration.

## Key findings

- At 60 days, the cross-linked membrane (OSX) showed the highest osteopromotive potential compared to other groups.
- MicroCT analysis revealed significantly higher bone volume in the cross-linked membrane group compared to the positive control.
- The cross-linked membrane was found to be biologically more favorable for bone regeneration.

## Abstract

Guided bone regeneration (GBR) is a critical strategy for repairing large bone defects. This study aimed to assess the osteopromotive potential of a porcine cross-linked collagen membrane in critical calvaria-defects in rats. Seventy-two rats were divided into three groups: blood clot (CG - negative control), Bio-Gide® membrane (BG - positive control), and Ossix Plus® membrane (OSX - test). The defects were covered according to each group, and the experimental times were 7, 15, 30, and 60 days postoperatively. The collected samples were evaluated by histometric analysis, inflammatory profile, immunohistochemistry, and micro-computed tomography (micro-CT). At 7 days, no significant differences in bone neoformation were observed. At 15 days, the OSX group showed increased new bone formation compared to CG (p = 0.031). At 30 days, the BG group exhibited the most significant increase compared to both OSX (p < 0.001) and CG (p < 0.001). At 60 days, OSX demonstrated the highest osteopromotive potential, significantly outperforming CG (p < 0.001) and BG (p < 0.001). MicroCT analysis revealed that the OSX group had a bone volume (BV) of 17.33 ± 1.74 mm3, significantly higher than BG (8.06 ± 1.26 mm3, p < 0.05). The cross-linked collagen membrane was biologically more favorable for bone regeneration being a promising option for GBR procedures.