The effect of reinforcement with woven E-glass fibers on the impact strength of complete dentures fabricated with high-impact acrylic resin.

STATEMENT OF PROBLEM

The fracture of acrylic maxillary complete dentures occurs frequently during service through heavy occlusal force or accidental damage.

PURPOSE

The purposes of this study were to measure the impact strength of maxillary complete dentures fabricated with high-impact acrylic resin and to evaluate the effect of woven E-glass fiber-reinforcement on the impact strength of the complete dentures.

MATERIAL AND METHODS

Preimpregnated woven E-glass fibers (Stick Net) were used to reinforce 10 complete denture bases fabricated with a heat-polymerized high-impact acrylic resin (Lucitone 199). Ten unreinforced complete dentures served as a control group. All specimens were stored in water at 37 degrees C for 2 months before testing. The impact strengths (J) of the dentures were measured with a falling-weight impact test. The impact strengths of both groups were compared by a repeated measures analysis of variance (alpha=.05). The Weibull distribution was also applied to calculate the cumulative fracture probability as a function of impact strength.

RESULTS

The mean impact strength of the control dentures was 90.0+/-38.1 J at crack initiation, and 95.9+/-37.7 J at complete fracture, whereas the impact strength of reinforced dentures was 201.7+/-77.9 J and 277.9+/-102.5 J, respectively. Statistical analysis showed that impact strength of the high-impact acrylic complete denture was significantly increased by the addition of woven E-glass fiber (P<.0001).

CONCLUSION

The impact strengths of maxillary complete dentures fabricated with high-impact acrylic resin increased by a factor greater than 2 when reinforced with woven E-glass fiber.