Inquiry

Adhesives and postoperative sensitivity

Background

When etch-and-rinse systems are used, the dental substrate is etched with phosphoric acid before the bonding solution is applied. This removes the smear layer and increases dentin permeability and the hydraulic conductance of dentin. With over-etching or scant adhesive application, the hybridized area may develop voids or the collagen fibrils can permit the movement of dentin fluid, usually when occlusal stress is applied. As a result, the patient can experience postoperative sensitivity (POS).

Methods

The literature search covered the databases of MEDLINE, Scopus, Web of Science, LILACS, BBO, Cochrane Library, SIGLE, IADR abstracts, unpublished and ongoing trials registries, dissertations, and theses. The goal was to identify randomized clinical trials (RCTs) that compared composite resin restorations placed with either self-etch or etch-and-rinse products in NCCLs. Fifty articles covering 42 studies were included in the analysis.

Results

POS was reported in about half of the studies, but the method of assessment varied. Some involved stimulation and other methods relied on spontaneous POS reports.

The risk of bias was considered high in 13 studies. Twenty-nine studies had a low risk, making them appropriate for quantitative analysis. All meta-analyses were performed on studies classified at low risk of bias. One meta-analysis was done of POS, and 4 addressed loss of restoration and marginal discoloration. In the meta-analysis

Discussion

The findings support the conclusion that adhesive strategy does not cause POS and is not responsible for this complication. No significant differences were noted between composite resin restorations placed with self-etching or etch-and-rinse adhesives with respect to retention, but marginal discoloration can be reduced with the use of the etch-and-rinse adhesives.