Hyaluronan does not improve bone healing in critical size calvarial defects in rats - A radiographic evaluation

Aim: This study evaluated radiographically the effects of 1% hyaluronan in bone healing using a critical size rat-calvaria defect model.
Methods: Thirty adult male Wistar rats were used in this study. Two 6-mm-diameter critical-size defects were created and the treatments were randomly distributed as follows: 1) 1% hyaluronan; 2) 1% hyaluronan soak loaded onto an absorbable collagen sponge (ACS) carrier; 3) saline; and 4) ACS alone. The animals were sacrificed at 4 and 8 weeks when biopsies were collected and radiographs obtained using a direct digital radiograph system and a standardized protocol. A blind examiner evaluated the radiographic density of the images twice and an intraclass correlation was performed to evaluate examiner reproducibility (R2=0.99, p<0.001). Comparisons between 4 and 8 weeks of treatment were performed by Student′s t test and comparisons between treatments and time by two-way ANOVA at 5% significance level.
Results: There were no noteworthy differences between 4 or 8 weeks within each treatment group (p>0.05). When treatments were compared no significant differences between groups were found (p>0.05).
Conclusions: Within the limits of this study, it can be concluded that 1% hyaluronan gel alone or its association with a carrier does not improve bone healing.