Comparison of Three Luting Cements for Prefabricated Zirconia Crowns in Primary Molar Teeth: a 36-month Randomized Clinical Trial.

Purpose: The purpose of this study was to evaluate and compare the long-term clinical retention and gingival health of prefabricated zirconia crowns (PZCs) in primary molar teeth cemented using three luting cements.

Methods: Primary molar teeth restored with PZCs (n equals 30 per group) were cemented using glass ionomer cement (GIC), resin-modified GIC (BioCem™), or adhesive resin cement (APC technique: air- particle abrasion, zirconia primer, composite resin). Crown retention, plaque accumulation, and gingival status were evaluated over three years; cumulative crown survival was assessed using Kalpan-Meier analysis. Plaque gingival scores were analyzed for within and between groups using repeated measures one-way analysis of variance.

Results: The survival of PZCs cemented using GIC was 76.7 percent, 70 percent for APC, and 50 percent for BioCem™ after three years. The mean survival for PZC in the GIC group (35.5 months) was significantly higher than for APC (34.7 months), and BioCem™ (33 months; P=0.019). Plaque accumulation around GIC-luted crowns was significantly lower (P<0.001; three-year follow-up); gingival outcomes were uniformly favorable between groups. No crown fracture was observed throughout the study period.

Conclusions: Prefabricated zirconia crowns cemented using traditional glass ionomer cement have superior retention and lower plaque accumulation compared to BioCem™ and APC after three years. PZCs provided long-term favorable gingival health outcomes irrespective of the cement used for luting the crowns.