Monomer priming of denture teeth and its effects on the bond strength of composite resin.
BACKGROUND
The bond strength of acrylic resin denture teeth used as pontics in fiber-reinforced composite fixed dental prostheses needs to be improved.


OBJECTIVE
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.


METHODS
Acrylic resin denture teeth of 2 different brands (Artic 8 and Vitapan Cuspiform) (n=120) 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.
Doctoral student, Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre, University of Turku, Turku, Finland. Electronic address: leila.perea@utu.fi.
Leila
L
Perea
Associate Professor in Dental Materials Science, Faculty of Dentistry, Dental Materials Science, The University of Hong Kong, Hong Kong SAR, P.R. China.
Jukka P
JP
Matinlinna
Researcher and Statistician, Department of Community Dentistry, University of Turku, Turku, Finland.
Mimmi
M
Tolvanen
Laboratory Head, Turku Clinical Biomaterials Centre, University of Turku, Turku, Finland.
Lippo V
LV
Lassila
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, Turku, Finland.
Pekka K
PK
Vallittu
D000180:Acrylic Resins / Q000737:chemistry*; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D003779:Denture Design; D003830:Denture, Partial, Fixed; D006244:Hardness; D006801:Humans; D055115:Light-Curing of Dental Adhesives; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D020366:Methylmethacrylate / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011092:Polyethylene Glycols / Q000737:chemistry; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000737:chemistry; D019904:Polymethyl Methacrylate / Q000737:chemistry; D011140:Polyurethanes / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013499:Surface Properties; D013997:Time Factors; D014093:Tooth, Artificial
D000180:Acrylic Resins; D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D011109:Polymethacrylic Acids; D011140:Polyurethanes; C029824:urethane dimethacrylate luting resin; C020946:triethylene glycol dimethacrylate; D020366:Methylmethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D019904:Polymethyl Methacrylate