Are flowable composite resins containing bioactive particles truly biocompatible?

To evaluate the degree of conversion and biocompatibility of flowable composite resins containing bioactive particles using in vitro and in vivo models, respectively.

The flowable composite resins Beautifil Flow Plus F00 (F00), Beautifil Flow Plus F03 (F03), and Filtek Supreme (FS) were tested. For the degree of conversion (DC) test, seven specimens were prepared for each group and analyzed using Raman spectroscopy. For biocompatibility (BC), seven specimens from each group were implanted into the dorsal subcutaneous tissue of 21 female Wistar rats, which were divided into three groups according to the experimental periods of 7, 14, and 28 days. After euthanasia, the dorsal tissues were surgically excised, fixed in formalin solution, and processed for histological analysis. The slides were evaluated blindly, and ten microscopic fields were randomly selected at 400× magnification. Statistical analysis for DC and BC was performed using the Kruskal-Wallis test, followed by Tukey's post hoc test for DC and Dunn's test for BC.

For BC, F00 and F03 induced less inflammation and granulation tissue formation and promoted greater fibrosis than FS (p < 0.05). For DC, no statistically significant difference was observed among the groups (p > 0.05).

Flowable bioactive composite resins represent promising alternatives for dental practice, as they induce minimal tissue inflammation and exhibit high conversion rates.