Statement of problem: Recently, in attempts to reinforce the acrylic resin and to reduce the polymerization shrinkage, it has been reported that adding vinyloligo-silsesquioxane (vinyl-POSS) to PMMA significantly compensates for polymerization shrinkage and somewhat increases the fracture resistance.
Purpose: There haven´s been any studies on abrasion that can affect the adaptation of the denture in long-term use. In this study, abrasion resistance was compared between acrylic resin with vinyl-POSS and commercialized acrylic resin for denture base. In addition, the difference in abrasion resistance according to molding methods was compared.
Material and method: Using PaladentR 20 including vinyl-POSS, PaladentR 20, Lucitone 199R, SR IvocapR, denture bases were fabricated using compression molding technique and continuous-pressure injection technique.
Surface hardness and abrasion were measured for each group, and the worn surfaces were observed under a scanning electron microscope.
Results:
1. When surface hardness was measured for each material and molding technique, there was no statistically significant difference among the materials. (p<0.05)
2. When same denture base material and molding technique were used, the abrasion due to tooth-paste solution was 5 times as severe as the abrasion due to soap solution.
3. When toothpaste solution was used, the abrasion decreased in the order of PaladentR 20, PaladentR 20 including vinyl-POSS, SR IvocapR, and Lucitone 199R. However, statistically significant difference was seen only among PaladentR 20, SR IvocapR, and Lucitone 199R.(p<0.05).
4. When soap solution was used, the abrasion was more severe in PaladentR 20 and including vinyl-POSS PaladentR 20 groups than in SR IvocapR and Lucitone 199R groups. (p<0.05).
Conclusion: Addition of vinyl-POSS doesn´t improve the abrasion resistance, and the abrasion resistance was similar to those of existing materials. Additional studies under different conditions are needed. For clinical application of vinyl-POSS, further investigations with different requirements and conditions are necessary.