Bond strength of soft liners to denture base resins and the influence of different surface treatments and thermocycling: A systematic review.

Statement Of Problem: Occasional debonding between soft liners and denture base resin is common and limits the longevity of a relined prosthesis.

Purpose: The purpose of this systematic review was to compare the bond strength of commercially available soft liners with that of polymethyl methacrylate (PMMA) and urethane dimethacrylate (UDMA) denture base resins after different surface treatments and thermocycling.

Material And Methods: Searches were performed by 2 independent reviewers in the MEDLINE/PubMed and Cochrane Library databases from January 1990 to December 2018 to identify published journal articles related to this subject. Subsequently, a hand search was also carried out for all the articles mentioned in the references of the identified full articles.

Results: A total of 61 articles were initially identified through database searches by the 2 reviewers. Twenty-four of the 61 articles met the inclusion criteria for qualitative analysis. Four of 6 articles showed that laser pretreatment of denture base resins increased their bonding to soft liners. Seven of 8 articles concluded that airborne-particle abrasion caused deterioration of the bonding between the liner and denture base resin. Four of 6 studies showed that acid etching, silica coating, primer or monomer application, and immersion in acetone or isobutyl methacrylate (iBMA) resulted in improved bond strengths between the liner and resin. One study reported that oxygen plasma treatment also resulted in improved bond strengths. Seven of 8 articles concluded that thermocycling resulted in decreased bond strengths.

Conclusions: Laser treatment, oxygen plasma pretreatment, primer or monomer application, and immersion in acetone or iBMA resulted in improved bonding of the denture base resin to soft liners. However, airborne-particle abrasion and thermocycling resulted in deterioration of the bond.