Histocompatibility of Dental Restorative Composite Resin Photopolymerized with a Novel Multifunctional Comonomer: A Histopathological Analysis in Rats

BACKGROUND: Restorative dentistry is impossible without composite resins. Toxicity of these resins is common though possessing favorable properties. Modifications of the resin matrix are being executed to improve the properties of the material. Dipentaerythritol penta-/hexa-acrylate (DPEPHA) monomer has been recently identified as a cross-linking comonomer with the conventional resin matrix. PURPOSE: This study aimed to investigate the histocompatibility of DPEPHA comonomer in photopolymerized resin at 20 and 40 wt.% concentrations in rats. MATERIALS AND METHODS: Eighteen male Wister rats were subjected to subcutaneous implantation of conventional resin specimens without DPEPHA (G0) and with DPEPHA at 20 wt.% (G20) and 40 wt.% (G40) concentrations. Then, the rats were subdivided according to the time of resection of the implantation sites at 1, 2, and 4 weeks (n = 6 rats). Tissue specimens were submitted to histopathological analysis. RESULTS: Except for 4 weeks' time interval, there were significant differences (P < 0.05) in the inflammation among the groups at each time interval. The order of inflammation was NC <G40 ≤G20 <G0. Concerning the fibrous capsule thickness, significant difference existed among the groups at each time interval and within the groups at all 3 time intervals (P < 0.05). CONCLUSION: Composite resin specimens with DPEPHA comonomer exhibited good histocompatibility in rats at 40 wt.% concentration.