Effects of Different Self-Adhesive Resin Cements and Curing Through Zirconia on Gingival Fibroblasts

Self-adhesive resin cements (SARCs) are widely used for fixed prostheses. These cements and their eluted products may affect periodontal tissues. This study aimed to investigate the response of human gingival fibroblasts (HGFs) to eluates from SARCs in vitro, simulating clinical conditions after prosthesis fixation, to gain insights into their potential effects on gingival health.

Two SARCs, RelyX U200 (RX) and Maxcem Elite Chroma (MC), were polymerised according to the manufacturer's protocols using various curing methods (light-cured, light-cured through 1- or 2 mm zirconia, and self-cured). HGFs were exposed to cement eluates at different concentrations. Cell viability, vitality, wound healing, and gene expression were assessed at different time points.

Self-cured MC and MC cured through 2-mm zirconia (both undiluted and 1:5 dilution) significantly decreased HGFs' viability. Lower cell viability and vitality were detected in MC compared with RX. Wound healing was delayed in cells treated with MC cured through zirconia compared to those cured with direct light, whereas zirconia had no effect on cells treated with RX. The expression of NRF2, a key regulator of cellular defence against oxidative and toxic insults, showed an increasing trend in cells treated with MC compared to RX. This finding suggests that MC may induce more oxidative stress than RX, leading to a more pronounced inflammatory response in HGFs and aligning with the observed delay in wound healing.

The use of MC, especially when cured through zirconia, may negatively impact gingival tissue health, highlighting the importance of carefully selecting cement types and curing methods in clinical practice.

This study highlights the potential risks of using MC, especially when cured through zirconia, which may impair gingival tissue health and delay wound healing. Proper choice of cement and curing methods is essential for optimal patient outcomes.