Study on the effects of zirconia restorations in oral prosthodontics on inflammatory factor levels and masticatory function

This study aims to compare the effects of zirconia all-ceramic crowns and metal-ceramic crowns on inflammation and chewing function in patients receiving full-crown restorations and to explore whether improvements in gingival health mediate these effects - an aspect rarely addressed in previous studies. A total of 196 patients treated from January 2023 to January 2024 were included. After propensity score matching, 79 patients in each group had similar baseline characteristics. Serum interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) levels were measured before treatment and at 6 weeks and 3 months after restoration. Masticatory efficiency, visual analogue scale (VAS) scores, gingival condition, and clinical success were also evaluated. Both groups showed significant decreases in IL-6, TNF-α, and CRP after restoration, with greater reductions in the zirconia group (3-month IL-6: 7.2 ± 2.0 vs 9.8 ± 2.5 pg/mL; TNF-α: 11.5 ± 2.7 vs 14.3 ± 3.0 pg/mL; CRP: 3.5 ± 1.0 vs 4.8 ± 1.3 mg/L; all P < .001). The zirconia group also showed higher chewing efficiency (78.6 ± 9.2% vs 70.2 ± 8.9%), higher VAS scores (7.8 ± 1.0 vs 6.9 ± 1.1), and fewer gingival symptoms (7.6% vs 17.7%, all P < .05). Mediation analysis revealed that part of the CRP reduction was mediated by improved gingival health, providing novel mechanistic insight. This study not only confirms the superior clinical and anti-inflammatory effects of zirconia restorations over metal-ceramic crowns but also identifies gingival health as a potential mediator linking restorative material and systemic inflammation. These findings provide new evidence for the biological advantages of zirconia in prosthodontic practice.