Effect of surface treatments and cyclic loading on the bond strength of acrylic resin denture teeth with autopolymerized repair acrylic resin.
BACKGROUND
Fracture of denture teeth from the denture base is a common problem associated with dental prostheses. Fractured tooth surfaces treated with chemical agents and mechanical features have the potential for improved repair strength.


OBJECTIVE
The purpose of this study was to compare bond strengths of denture teeth to autopolymerized repair acrylic resin after various surface treatments, before and after cyclic loading.


METHODS
Mandibular lateral incisor denture teeth were selected and ground on the ridge-lap portion using a standardized jig. Specimens with a ground surface were used as controls. The experimental groups included: ground plus airborne-particle abraded, ground plus diatoric recess, and ground plus an experimental bonding agent. The teeth were affixed by an autopolymerized repair acrylic resin to denture bases. Specimens (n=10) were subjected to compression testing (5 mm/min) at a 135-degree angle, before and after 14,400 loading cycles at 2 Hz and 22 N. Peak load to dislodgement was recorded and statistically analyzed (2-way ANOVA, Tukey HSD, alpha=.05). The specimens were then examined using x10 magnification, and fractures were categorized as adhesive, cohesive, or mixed.


RESULTS
The mean bond strengths ranged from 26.3 N to 44.2 N. There were no significant differences in fatigue versus nonfatigue strength values within each group (P=.244). Significant strength differences were found (P<.001) between the ground control, diatoric recess, and bonding agent groups. Microscopic examination revealed that the bonding agent group obtained the highest percentage of mixed-type fractures.


CONCLUSIONS
The use of a bonding agent and the placement of a diatoric recess in the denture tooth resulted in higher bond strengths than grinding alone. Cyclic loading had no significant impact on the bond strength of denture teeth to the autopolymerized repair acrylic resin.
Meng
Graham K
GK
School of Dentistry, University of Washington, Seattle, WA 98195-7456, USA.
Chung
Kwok-Hung
KH
Fletcher-Stark
Madelyn L
ML
Zhang
Hai
H
D000180:Acrylic Resins; D000704:Analysis of Variance; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D003819:Denture Bases; D003780:Denture Repair / Q000379:methods; D055116:Self-Curing of Dental Resins; D033081:Shear Strength; D018709:Statistics, Nonparametric; D013499:Surface Properties; D014093:Tooth, Artificial
D000180:Acrylic Resins