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INTRODUCTION: The aim of the study is to evaluate interfacial bond strength between silicone prosthetic elastomers and polymethylmethacrylate (PMMA). MATERIALS AND METHODS: Silicone elastomers were attached to PMMA and a total 120 specimens were fabricated which were then subdivided into 12 sub-groups. Each sample was then subjected to laboratory test to determine the bond strength. The specimen of silicone elastomer bonded to acrylic of different surfaces was placed into universal testing machine (HOUNSFIELD HT-400) for "PEEL TEST". All the values obtained were tabulated and subjected to statistical analysis. RESULT: The bond strength of silicone elastomer to acrylic resin (TRAVELON) noticed highest (Mean 4.826 ± 0.008 n/mm) when only primer was used as a surface treatment. When silicone elastomer bonded to acrylic resin (DPI) showed the bond strength of (4.351 ± 0.0089) when only primer was used as a surface treatment. Whereas the least bond strength values were found when the silicone bonded to acrylic surface treated by 120 grit sand paper that is (0.076 ± 0.00 n/mm) and (0.082 ± 0.01 n/mm) for DPI and TRAVELON respectively. CONCLUSION: The bond strength of silicone elastomer to acrylic resin was higher when primer was used on the acrylic surface. The bond strength of silicone elastomer to acrylic resin was more with travelon resin when compared to DPI resin. But when silicone was bonded to acrylic surface with sand papering, showed less bond strength.
RESUMO
PURPOSE: The purpose of this study was to evaluate the mean maximum bite force in dentulous and edentulous individuals with Angle's class-I occlusion and to assess the effect of different facial forms such as Square, Square-tapering, tapering and ovoid on the biting force. MATERIALS AND METHODS: The study consisted of 160 subjects in total. Out of these 160, 80 were dentulous subjects and remaining 80 were edentulous subjects who had received treatment for his/her missing teeth by fabrication of a complete denture. The mean maximum voluntary bite force for every subject was measured using bite force measuring device,(Process indicator 3016). Face form was divided under square, tapering, square-tapering or oval types. The shape of the face was determined using digital photographs. The effect of edentulism, gender and face form on bite force was statistically analyzed using ANOVA, Scheffe and Sample t-tests. RESULT: Mean maximum bite force and standard deviation (S.D.) in the dentulous sample population was 41.3(13.9) kilograms (kg) which when compared with the edentulous sample population provided highly significant statistical result. The mean maximum biting force in edentulous sample population was 4.43 (2.4) kg (p<0.001). In both dentulous and edentulous categories, the mean maximum bite force was statistically higher in male patients than female patients. Mean maximum bite force was significantly higher in patients with square facial form than in subjects with other facial forms. CONCLUSION: Square face form contributes to higher bite force values by obtaining higher Mechanical advantage from muscles of mastication. RESULT also proved that patients with complete denture with any facial form have much lower mean maximum bite force when compared to dentate subjects.
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PURPOSE: The purpose of the study is to quantify occlusal errors seen, during the processing of complete denture. MATERIAL AND METHODS: Maxillary and mandibular complete dentures were fabricated for 30 subjects. Anterior and posterior markings were made on articulator and the distance was measured from these points before and after processing of complete dentures. Occlusal errors following processing of complete dentures was determined by subjecting the values obtained to statistical analysis using paired t-test. RESULTS: The results indicated the existence of discrepant amount of occlusal errors following processing of complete denture and statistical test applied was paired t-test, p-values obtained are, p=0.00 anterior reference markings and p=0.006 for posterior reference markings (p ≤ 0.001 highly significant). CONCLUSION: The processing errors are inevitable. Hence for patient comfort, laboratory remounting is an important procedure that needs to be followed as a regular step after processing of each and every denture.
