Randomized clinical trial on the survival of lithium disilicate posterior partial restorations bonded using immediate or delayed dentin sealing after 3 years of function

The survival and success rate and the quality of survival of partial ceramic restorations bonded employing Immediate (IDS) or Delayed Dentin Sealing (DDS) in vital molar teeth were evaluated in a randomized clinical trial with within-subject comparison study. 30 patients received two lithium disilicate ceramic (IPS-e.max press, Ivoclar Vivadent) partial restorations on vital first or second molar teeth (N = 60). The two teeth randomly received either IDS (test group, n = 30) or DDS (control group, n = 30). Partial ceramic restorations were luted (Variolink Ultra, Ivoclar Vivadent) two weeks after preparation. Evaluations were performed at 1 week, 12 months and 36 months post-operatively, using qualitative (FDI) criteria. Representative failures were evaluated microscopically (SEM) and by means of simplified qualitative fractography analysis. One absolute failure occurred in the DDS group due to (secondary) caries. The overall survival rate according to Kaplan-Meier after 3 years was 98.3% (FDI criteria score 1–4, n = 59) and the overall success rate was 85% (FDI criteria score 1–3, n = 51), with no significant difference between restorations in the IDS and DDS group (p = 0.32; Kaplan-Meier, Log Rank (Mantel-Cox), CI = 95%). For the quality of the survival, no statistically significant differences were found between IDS and DDS (p = 0.7; Kaplan-Meier, Log Rank (Mantel-Cox), CI = 95%) restorations on any follow-up timepoints for any of the FDI criteria (Wilcoxon, McNemar, p > 0.05). Adhesively luted partial ceramic restorations in vital molar teeth have a good prognosis, however IDS did not show any differences in success and survival rates after 3 years of function.