Effect of Primers on Shear Bond Strength Between Denture Base Acrylic Resin and Gingiva-shade Composite Resin

Objectives: The aim of this study was to investigate the shear bond strength between the denture base acrylic resin and gingiva-shade composite resin (GSCR) depending on the use and type of primers.
Methods: Two kinds of commercial heat-curing denture resin (Paladent 20 and Ivocap) and GSCR (Twiny and Crea.lign) with three kinds of primer groups (Non-primer, Visio.link and Palabond) were chosen to test shear bonding strength according to ISO 11405. (n=15). GSCR specimens, 6 mm in diameter and 2.5 mm in height were buildup by two-step layering in the centure and cured by a LED light. Specimens were soaked in 37°C distilled water for 48 hr. A total of 180 samples were tested. A three-way ANOVA was used to analyze the effects of the denture resin materials, primer treatments, GSCR and their interactions on shear bond strength.
Results: Shear bond strength of non-primer groups significantly lower in comparison with primer-use groups in both denture resin. Mean shear bond strength between denture base resin and GSCR was ranged from 1 to 13 MPa, depending on the type of primer and GSCR. In the results of three-way ANOVA, only GSCR and their interactions with primer were significant. on shear bond strength (P<.05).
Conclusions: Proper selection of GSCR and primer combinaiton would be important to increase of the shear bond strength between GSCR and denture base resin.