Influence of Glass Ionomer-based Luting Cements on the Clinical Success of Zirconia Crowns: Randomized Clinical Trial.

Objective: This study evaluated the influence of two types of glass ionomer-based luting agent on the clinical performance of metal-free zirconia crowns.

Methods and materials: Thirty participants received two full crown restorations in either anterior or posterior teeth, in a split-mouth design. After tooth preparation, impressions with addition-cured silicone were made and casts were obtained. The casts were scanned and 3Y-TZP zirconia copings (Ceramill ZI - Amann Girrbach) were milled using a CAD/CAM system. Glass ceramic (IPS E.max Ceram, Ivoclar Vivadent) was used to create the crown shape. For each participant, one crown was cemented using a conventional glass ionomer (GIC - Meron, Voco), while the other received a resin-modified glass ionomer cement (RMGIC - Meron Plus QM, Voco). The restorations were evaluated by two calibrated examiners after seven days, one year, and two years. The parameters at each evaluated time were analyzed by the Fisher exact test (α=0.05).

Results: At two years postoperatively, 24 participants attended the recall, and 46 (76.67%) restorations were evaluated. No fractures or secondary caries were diagnosed. Minimal marginal staining was verified in both cements. During the follow-up period, only two anterior crowns cemented with conventional glass ionomer showed loss of retention. No loss of retention was detected in posterior crowns.

Conclusion: After two years of intraoral service, the crowns cemented with either conventional glass ionomer cement or resin-modified glass ionomer presented acceptable and similar clinical performance for all parameters analyzed in both anterior and posterior teeth.