Tensile Bond Strength of a Highly Cross-Linked Denture Tooth to the Compression-Molded and Injection-Molded Denture Base Polymers

Abstract

This study compared tensile bond strengths between conventional compression-molded heat (HC)-, auto (AP)-, and microwave-polymerized (MC) poly(methyl methacrylate)-based denture resins and a relatively new injection-molded, microwave-polymerized polyurethane based resin (MI) bonded to a highly cross-linked denture tooth. In the first part of the experiments, denture teeth were used as received. In the second part, they were treated with dichloromethane to see its effect on bonding of conventional denture bases (HCS and APS). Bond strength was tested in tension according to ADA specification No.15. The results showed that the HC group failed cohesively because of higher interface bonding (49.95 MPa) compared with those of the others (AP: 25.41 MPa; MC: 22.06 MPa; MI: 20.02 MPa). The application of dichloromethane improved bond strengths of HCS and APS groups (60.61 and 32.03 MPa, respectively). It was suggested that dichloromethane could be applied on the denture teeth ridge lap area prior to denture base processing to enhance adhesion between the tooth/resin.

Keywords:

• Cross-linked denture teeth
• Denture base resins
• Interpenetrating network (IPN)
• Tensile bond strength

ACKNOWLEDGMENTS

This study was partly supported by The State Planning Organization, Prime Ministry, Republic of Turkey (Project No. 2001-K-120540).

Special thanks are due to Prof. Gungor Gunduz, Department of Chemical Engineering, Middle East Technical University, for his invaluable contributions in explaining the test results. Also, our thanks are extended to Assoc. Professor Ali Fazil Yenidunya, Research Centre for the Medical School of Cumhuriyet University, for his invaluable contribution in the preparation of this manuscript for submission.

Notes

∗According to manufacturers' data sheet.

PMMA = poly(methyl methacrylate); MMA = methyl methacrylate; EGDMA = ethylene glycol dimethacrylate; QAC = quartenary ammonium chloride.

n = 10 specimens per experimental condition.

Standard deviations are shown in parentheses.

By the one-way ANOVA: F = 120.750, P = 0.000, p < 0.01.

Values with the same superscript letter are not statistically different at p > 0.05; others not superscripted differ significantly among themselves at p < 0.05 by LSD Test.