Clinical Evaluation of the Marginal Adaptation of Metal-Ceramic and All-Ceramic Fixed Partial Dentures Using...

Introduction Marginal adaptation is a key factor in the biological and mechanical success of fixed partial dentures (FPDs). This study aimed to clinically compare the marginal adaptation of metal-ceramic and all-ceramic FPDs cemented with resin-modified glass ionomer cement (RMGIC) and self-adhesive resin cement. Materials and methods This prospective clinical observational study included 60 patients who required three-unit posterior FPDs. The patients were allocated into two groups: metal-ceramic (n = 30) and all-ceramic (n = 30). Each group was subdivided according to the luting cement used: RMGIC or self-adhesive resin cement (n = 15 each). Standardized clinical and laboratory protocols were used. Marginal adaptation was assessed using the modified United States Public Health Service (USPHS) criteria immediately after cementation and at three months by calibrated, blinded examiners. Data were analyzed using non-parametric tests and analysis of covariance (ANCOVA), with significance set at p < 0.05. Results At baseline, all groups demonstrated a clinically ideal marginal adaptation, with a median USPHS score of 1. Mean baseline scores ranged from 0.73 to 1.00 across subgroups. At three months, metal-ceramic FPDs cemented with RMGIC showed the highest mean USPHS score (2.6 ± 0.51), indicating greater marginal discrepancy. All-ceramic FPDs cemented with self-adhesive resin cement demonstrated the lowest mean score (0.87 ± 0.83), followed by metal-ceramic FPDs with self-adhesive resin cement (1.73 ± 0.70). Intergroup comparisons showed significantly better marginal adaptation in all-ceramic restorations than in metal-ceramic restorations (p < 0.001). Cement type also significantly influenced the outcomes, with self-adhesive resin cement performing better than RMGIC (p < 0.001). No significant interaction was observed between the restoration type and cement type (p = 0.913). Conclusion All-ceramic FPDs demonstrated superior early marginal adaptation compared with metal-ceramic restorations. The use of self-adhesive resin cement resulted in improved marginal integrity irrespective of the restoration type.