Biodegradation of three different collagen membranes in the rat calvarium: A comparative study

Background: Collagen barrier membranes are commonly applied in periodontal and bone-regenerative procedures. Membranes differ in their resorption pattern following implantation, thus influencing clinical outcome. The purpose of this study was to quantitatively evaluate the biodegradation of three different commercially available collagen membranes. Methods: Collagen membranes were cut into 5-mmdiameter disks and labeled with aminohexanoyl-biotin-Nhydroxy- succinimide ester. One membrane disk of each type (non-cross-linked [MCL], glutaraldehyde cross-linked [GCL], and ribose cross-linked [RCL]) was implanted on the calvaria of 20 Wistar rats. Block sections were retrieved after 2 days (baseline, two animals), 14 days (10 animals), or 28 days (eight animals). Decalcified histologic sections were stained with streptavidin horseradish peroxidase. Residual membrane thickness and area were measured. Statistical analysis consisted of analysis of variance (ANOVA) with repeated measures. Results: Statistically significant differences in the amount of residual membrane material were recorded within each membrane (among different time points) and among different membranes at the same time points (P<0.001 ). At 28 days, the least amount of residual collagen area, expressed as the percentage of baseline, was observed in the NCL group (13.9% ± 10.25%), followed by the GCL (24.7% ± 35.11%) and RCL (91.3% ± 10.35%) groups. Residual membrane thickness, expressed as the percentage of baseline thickness, presented a similar pattern (31% ± 16.55%, 37% ± 41.90%, and 94.1% ± 12.22%, respectively). ANOVA with repeated measures showed a significant interaction between membranes and time (P<0.001). Conclusions: The tested membranes differed in their degradation patterns and collagen contents. Membranes should be chosen for each clinical case according to the desired biodegradation characteristics.