1-Year clinical study of indirect resin composite restorations luted with a self-adhesive resin cement: effect of enamel etching

Abstract

In vitro studies have recommended enamel-etching before luting indirect restorations with self-adhesive resin cement. However, there is no scientific proof that this procedure has any clinical relevance. Thus, the aim of this study was to evaluate the effect of enamel-etching on the marginal quality of indirect composite resin restorations (inlay/onlay) using the self-adhesive cement RelyX Unicem clicker. Forty-two posterior teeth were selected from 25 patients that presented one or two teeth with large restorations in need of replacement. All teeth were prepared by the same operator and impressed with polyvinylsiloxane material. The composite resin restorations were built over plaster casts using the incremental technique with a LED device for light-curing the increments. The inlays/onlays were cemented according to one of the following protocols: 1. Etched group (ETR) - selective enamel phosphoric-acid etching + RelyX Unicem clicker; 2. Non-etched group (NER) - RelyX Unicem clicker alone. Each surface was light-cured for 60 s. Recalls occurred after 1 week (baseline), 6 and 12 months when the teeth were evaluated according to previously established scores (modified USPHS criteria). The clinical analysis showed little or no visible changes in the marginal quality after 1 year, even though a probe could detect all the restorations margins. Statistical analysis (Fisher's exact test, p<0.05) detected no differences between the groups after 12 months. No restorations failed and no secondary caries were found. Enamel acid etching had no clinical relevance on the marginal quality of indirect composite resin restorations luted with RelyX Unicem clicker after 1 year of follow up.

Self‐Adhesive Resin Cements: A Clinical Review

“…Furthermore, marginal discoloration was also found to be higher in the nonetch group, probably because the fillers were cropped out from the resin matrix during tooth brushing . Azevedo et al also stated that enamel etching had no clinical relevance on the marginal quality of indirect composite resin restorations. Overall, the advantage of selective enamel etching upon marginal adaption in the clinical situation could not be confirmed by either of these two studies, although it was advocated for in vitro studies; however, it should be mentioned that, in these two studies, RelyX was bonded to enamel surfaces only.…”

“…Six of the 14 in vivo studies found dealt with this issue . All authors agreed that self‐adhesive resin cements showed less postoperative sensitivity than the classic total‐etch technique or conventional cements, such as glass ionomer or zinc phosphate cements.…”

“…Six of the 14 in vivo studies found dealt with this issue. 12,21,24,[31][32][33] All authors agreed that self-adhesive resin cements showed less postoperative sensitivity than the classic total-etch technique or conventional cements, such as glass ionomer or zinc phosphate cements. The main problem of the total-etch technique is the acid etching of the dentinal surface, particularly when systems are used incorrectly.…”

Bonding efficacy of a self-adhesive resin cement to enamel and dentin

“…The bonding mechanism of this cement is not yet completely understood, but differs from that obtained with self-etched adhesives as no distinct demineralization and hybridization was observed during TEM morphological interface examination [24,25] . Many laboratory and clinical studies [26][27][28] noticed an inefficient bonding effectiveness for this particular adhesive. It is well reported that acid etching provides the most reliable bond strength to enamel [32] .…”

Effect of different surface penetrating sealants on the roughness of a nanofiller composite resin

“…Since the introduction of bonding systems and composite resins, wear and microleakage were the primary clinical limitations, mainly in posterior restorations (1)(2)(3)(4)(5)(6)(7)(8). The relative porosity of the restorative and absorption/adsorption of oral fluids may also allow staining agents to penetrate the material (9).…”