The aim of this study is to evaluate the effect of peracetic acid and ozone disinfection on the tensile bond strength (TBS) of silicone-based resilient denture liners to denture base acrylic resins.
Method:
One hundred and twenty dumbbell shaped heat-polymerized denture base resins were prepared according to ASTM D-412 standards. Two different resilient denture liners from same manufacturer were used; Mollosil, autopolymerized and Molloplast B, heat-polymerized silicone-based resilient liner. From the mid segment of the dumbbell shape specimens, 3mm of acrylic were grinded off and separated parts were reattached by resilient liners. The specimens were divided into 2 control (control1, control7) and 4 test groups of PAA and ozone disinfection (PAA1, PAA7, ozone1 and ozone7; n=10). Tensile tests were performed after; immersion in distilled water (37oC) for 10 min or 1 hour and 7 days for the control groups. The specimens of PAA and ozone test groups were subjected to PAA (16 g/l) or ozone rich water (4 mg/l) exposure 1cycle (10 min for PAA and 60 min for ozone) and 1cycle/day for 7 days prior to tensile tests. Measurements of the TBS were analyzed using 3-way ANOVA and Tukey’s HSD test.
Result:
Mean TBS values (MPa) of resilient liners evaluated are given in the table below.
|
Control1 |
Control7 |
PAA1 |
PAA7 |
Ozone1 |
Ozone7 |
Mollosil |
1.28(0.21)Aa |
1.18(0.13)Aa |
1.22(0.14)Aa |
1.11(0.19)Aa |
1.02(0.15)Ab |
0.90(0.09)Ac |
Molloplast B |
1.76(0.23)Ba |
2.37(0.27)Bb |
1.85(0.16)Ba |
2.15(0.25)Bb |
2.30(0.30)Bb |
1.82(0.25)Ba |
Different superscripted uppercase letters indicate statistically different means within each column (P<.05).
Different superscripted lowercase letters indicate statistically different means within each row (P<.05).
Conclusion:
Within the limitations of this study, the adhesion of all tested resilient liners was not adversely affected by PAA disinfection method. Immersion in ozone rich water significantly decreased TBS of the autopolymerized silicone-based resilient liner. Prolonged exposure to ozone negatively affects adhesion of resilient liners to denture base materials.