Comparative evaluation of tensile bond strength of two commercially available liners following pretreatment of denture surface with oxygen plasma and laser- an In vitro study

Debonding of the soft liner from the denture base is a major problem that plagues their longevity. Various surface modifications have been introduced to increase the bond strength. But no studies have been conducted comparing the bond strength between denture liners and acrylic resin following Plasma-oxygen and laser treatment. A total of 108 rectangular denture base resin blocks each having a cross-sectional area of 10mm × 10mm and 40 mm length were fabricated. The blocks were divided into 2 groups (n=54) each for bonding with the 2 soft liners (Group 1-Molloplast-B, Group 2-Permasoft). Sample for tensile bond testing was made by packing a soft liner of 3mm thickness between the 2 blocks. Each group was further divided into 3 subgroups based on the surface treatment of the bonding surfaces of the resin blocks i.e. Group A- control (untreated, n=9) Group B-laser treated (n=9) and Group C-Plasma-oxygen treated (n=9). The samples were subjected to tensile stress in universal testing machine at a crosshead speed of 5mm/min. The data was tabulated and subjected to statistical analysis using One way-ANOVA test. Results of this study showed that Plasma-oxygen treatment was more effective in increasing the bond strength as compared to laser pre treatment.