The Impact of Adhesion Strategy on the Clinical Performance Of Indirect Dental Restorations

The goal of this clinical trial is to evaluate whether different cement systems influence the clinical outcome of posterior tooth supported zirconia crowns in adult patients requiring single crown restorations. The main questions it aims to answer are: * Do glass ionomer cements provide clinical outcomes comparable to those of resin cements for posterior zirconia crowns? * Do marginal discoloration, marginal integrity, and biological complications differ between the cement systems? * Do patient reported and clinician reported outcomes differ between the cementation procedures? Researchers will compare zirconia crowns cemented with either a glass ionomer cement or a resin cement to evaluate differences in clinical outcomes. Participants will: * Receive posterior zirconia crowns fabricated according to standardized clinical procedures * Be randomized to cementation with either a glass ionomer cement or a resin cement * Undergo clinical examinations assessing crown survival, marginal adaptation, discoloration, caries, periodontal status, and wear * Complete questionnaires regarding patient comfort and treatment experience * Attend baseline and annual follow-up examinations for up to 10 years