11 April 2022

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Does Immediate dentin sealing improve bonding procedures of posterior lithium disilicate partial restorations?

Co-authors: A. Comba, F. Florenzano

Lorenzo Breschi

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The advent of adhesive dentistry, years ago, introduced the concept of minimally invasive dentistry with more conservative cavity design and no mechanical retentions. When sufficient dental structure is present, a direct composite restoration is the treatment of choice, however,  partial adhesive ceramic restorations are indicated when the remaining tooth structure is not able to support a direct reconstruction. Among ceramics, feldspatic porcelain and glass ceramic such as lithium disilicate, are etchable materials that can be adhesively bonded to the dental substrate. While adhesion to enamel is more predictable, adhesion to dentine, has always been an issue.Immediate dentin sealing (IDS) has been suggested as a technique to improve adhesion, compared to delayed dentin sealing (DDS).
IDS consists of a thin layer of adhesive resin is applied immediately after tooth preparation and prior to impression taking, whereas in DDS, the adhesive resin layer is applied just before luting the restoration.
 A study condacted by Van der Breemer et al. aimed to compare survival rate of lithium disilicate posterior partial restorations bonded using IDS after 3 years of function.

Materials and methods
 To conduct the study, the research group selected 30 patients who received two lithium disilicate ceramic partial restoration ( IPS-e.max press, Ivoclar Vivadent) 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.

Results
 The data collected by Van der Breemer et al. revealed that only 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%). As concern 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).

Conclusions
Based on the obtained data, the authors concluded that adhesively luted partial ceramic restorations in vital molar teeth have a good prognosis, however IDS did not show statistically significant differences in success and survival rates after 3 years of function.  

 

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