Methods: 69 specimens were fabricated;composed of soft lining Molloplast-B bonded to different interfaces of heat cured Universal Minacryl. Primo adhesive was brushed over interfaces, and left for 90 minuntes. A disk mould (8mm diam, 3mm deep) covered all interfaces, and Molloplast-B packed against them. Thus groups were: •Group 1: 23 specimen of non-reinforced smooth acrylic surface bonded to Molloplast-B. •Group 2: 23 specimen of non -reinforced rough acrylic surface bonded to Molloplast-B. •Group 3: 23 specimens of StickTech Net fibre-reinforced surfaces bonded to Molloplast-B. All specimens were thermocycled for 3000 thermal cycle. Shear test was conducted with Zwick Roell(Z020) Universal Testing Machine at crosshead speed of 2mm/min. Micrographs of debonding sites were captured at magnification of X40. Bond failure categories were: •Type 1: adhesive failures at interface. •Type 2: cohesive failures within Molloplast-B. •Type 3: mixed failures.
Results: For groups 1-3 respectively, minimum bond strengths were: 0.49, 0.46, and 0.58 MPa. Maximum bond strengths were: 0.98, 0.83 and 1.00 MPa. The mean forces (SD) were: 0.71 (0.15), 0.63 (0.070) and 0.83 (0.12) MPa. One way ANOVA showed statistical significance (p<0.05). Bonferroni post-hok test for multiple comparisons between groups indicated that group 3 had the highest bond strength, and it was statistically significant over other two groups. The modes of failures were different. Groups (1&2) exhibited Types 2&3 and group3 exhibited Type 2 only. Conclusions: Acrylic interfaces tested appear to have clinically acceptable range of bond strength. StickTech Net fibre-reinforced surfaces exhibited stronger, durable and more reliable bond to Molloplast-B over non-reinforced surfaces, since Molloplast failed cohesively at the interface when bonded to Net fibre-reinforced surfaces.