COMPARATIVE EVALUATION OF OXIDATIVE STRESS, INFLAMMATORY RESPONSE AND CELLULAR INJURY ASSOCIATED WITH DIFFERENT RESTORATIVE MATERIAL EXPOSURE

Abstract

Background: Restorative materials may release chemical components capable of interacting with surrounding oral tissues. Although cytotoxicity has been investigated extensively, the relationship between oxidative stress, inflammatory signaling and cellular injury associated with different restorative materials remains incompletely characterized. This study compared the biological responses of human gingival fibroblasts exposed to commonly used restorative materials.

Methods: An in-vitro experimental study was conducted using cultured human gingival fibroblasts. Disc specimens of resin composite, conventional glass ionomer cement (GIC), resin-modified glass ionomer cement (RMGIC), and compomer were prepared according to standardized procedures. An untreated cell culture served as the control. Material extracts were prepared and applied to fibroblast cultures for 24 and 72 hours. Cell viability was assessed using the MTT assay, while cellular membrane injury was evaluated using lactate dehydrogenase (LDH). Oxidative stress was assessed using reactive oxygen species (ROS) and malondialdehyde (MDA), while inflammatory responses were evaluated by measuring interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α). Data were analyzed using one-way analysis of variance with appropriate post-hoc comparisons.

Results: Significant differences were observed among the material groups for cell viability, ROS, MDA, IL-6 and TNF-α levels (p<0.001). At 72 hours, cell viability was highest in the control group (100.0 ± 4.8%) and lowest following exposure to RMGIC (67.4 ± 5.9%), followed by resin composite (72.8 ± 6.2%), GIC (79.6 ± 5.7%) and compomer (85.3 ± 5.1%). RMGIC produced the highest ROS and MDA levels and demonstrated significantly greater LDH release than the other restorative materials. IL-6 and TNF-α concentrations were also significantly elevated following RMGIC and resin-composite exposure compared with the control group.

Conclusion: Different restorative materials produced distinct biological responses in human gingival fibroblasts. RMGIC demonstrated the greatest oxidative, inflammatory and cellular injury responses in the experimental model, whereas compomer showed comparatively lower biological effects. The findings support the importance of evaluating oxidative stress and inflammatory responses alongside conventional cytotoxicity assays when assessing the biological compatibility of restorative materials.