Monomer priming of denture teeth and its effects on the bond strength of composite resin Leila Perea, DDS, MSc, a Jukka P. Matinlinna, MSc, PhD, b Mimmi Tolvanen, PhD, c Lippo V. Lassila, DDS, d and Pekka K. Vallittu, DDS, PhD e University of Turku, Turku, Finland; The University of Hong Kong, Hong Kong SAR, P.R. China Statement of problem. The bond strength of acrylic resin denture teeth used as pontics in fiber-reinforced composite fixed dental prostheses needs to be improved. Purpose. The purpose of this study was to assess the influence of various chemical surface-conditioning monomers on the ridge-lap surface of acrylic resin denture teeth by determining the strength of their bonding to a composite resin and changes in surface hardness. Material and methods. Acrylic resin denture teeth of 2 different brands (Artic 8 and Vitapan Cuspiform) (n¼120) were tested. Four monomer systems were used as surface primers (conditioning): a flowable composite resin, methylmethacrylate 99%, composite primer, and a photopolymerizable dimethacrylate resin. Five surface-conditioning exposure times were used: no conditioning, 1, 5, 15, and 60 minutes. Surface microhardness measurements were made after the application of the monomer systems. Shear bond strength tests were subsequently performed, followed by a new surface microhardness indentation after the application of the load. The evaluation of the changes on specimen surfaces was performed with a scanning electron microscope. The differences between the shear bond strength and the surface hardness were evaluated for statistical significance by using a 3-way ANOVA. Results. Tooth brand, monomer used, exposure time, and their 2- and 3-way interactions had a significant effect on the shear bond strength and hardness before and after testing, except for the 3-way interaction effect on hardness before testing. Conclusions. The chemical pretreatment of the ridge-lap surface of acrylic resin denture teeth increased the shear bond strength and influenced the surface hardness. The monomer systems caused dissolution on the denture surfaces. (J Prosthet Dent 2014;-:---) Clinical Implications The higher shear bond strength of acrylic resin denture teeth used as pontics may increase the durability and clinical effectiveness of fiber-reinforced composites fixed dental prostheses. Acrylic resin denture teeth are used in prosthetic dentistry as compo- nents of removable and fixed dental prostheses (FDP) because of their advantages over porcelain teeth. Such benefits include their prefabricated shape and pleasing shade, adequate mechanical strength, easy occlusal ad- justment, and high bond strength to Presented at the European Prosthodontic Association and the Scandinavian Society for Prosthetic Dentistry annual meeting, Turku, Finland, August 2013. a Doctoral student, Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre, University of Turku. b Associate Professor in Dental Materials Science, Faculty of Dentistry, Dental Materials Science, The University of Hong Kong. c Researcher and Statistician, Department of Community Dentistry, University of Turku. d Laboratory Head, Turku Clinical Biomaterials Centre, University of Turku. e Professor and Chair of Biomaterials Science, Director of Turku Clinical Biomaterials Centre, Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre, University of Turku. Perea et al