In vivo biocompatibility of Resilon compared with gutta-percha in a pre-clinical model

Abstract

Background: The aim of this study was to investigate in vivo biocompatibility of Resilon, compared with

gutta-percha, at short and long-term following implantation in a rat subcutaneous implantation model.

Materials and Methods: Male Wistar rats were implanted subcutaneously with either Resilon

or gutta-percha or were sham controls. Tissues were harvested at 8 days or 60 days after

implantation and were evaluated histologically for inflammation and fibrous encapsulation. The

severity of histologic injury, scored on a scale of 0-4 and quantitative analysis of the capsule wall

thickness were determined for statistical analysis. Data were analyzed by Student t-test, one-way

analysis of variance, Kruskal-Wallis or Mann-Whitney’s tests as appropriate. A value of P ≤ 0.05

was considered statistically significant.

Results: No behavioral changes or visible signs of physical impairment were observed at 8 days

or 60 days post-implantation. Histopathologic observation of the implanted sites at each timepoint

showed that both Resilon and gutta-percha implants induced foreign body reaction, showing

minimal to mild inflammatory reactions in most cases, which diminished significantly with time.

Compared with gutta-percha, the capsule wall was thinner (P > 0.05) after Resilon implantation

at day 8 and significantly (P = 0.01) thicker at day 60. In addition, capsule wall thickness showed

a trend to increase with time after implantation in the Resilon groups (P > 0.05), opposed to the

significant decrease (P = 0.016) observed after implantation in the gutta-percha groups, suggesting

lesser long-term biocompatibility of Resilon.

Conclusion: Our findings validate Resilon as an in vivo biocompatible material. However, our data

suggest that long-term biocompatibility of Resilon, despite validated, is inferior to that of guttapercha

control.

Key Words: Endodontic materials, gutta-percha, rat, Resilon, subcutaneous implantation