This study aimed to compare the von Mises stress distribution and deformation on the implant, abutment, and abutment screw using metal-ceramic, zirconia, polyether ether ketone (PEEK), and Trinia as prosthetic materials for full-mouth cement-retained implant prosthesis using finite element analysis. Four, 3-dimensional mandibular models were designed using Solidworks software. Six conical implants of 4.5 × 11.5 mm, with an internal hexagonal abutment, were fabricated and placed. The physical properties of the implant components, bone, and crowns were simulated to mesh the three-dimensional finite element models. The bite was recorded, and various contact points were marked, on which 50 N loads were applied. The von Mises stress distribution and resultant deformation were analyzed using the finite element method. Higher stress distribution was recorded on the implants, abutments, and abutment screws when zirconia and PEEK prosthesis were used in comparison to metal-ceramic and Trinia. In consideration of deformation, zirconia and Trinia resulted in higher deformation of the implant assembly, abutment, and abutment screw when compared to metal-ceramic and PEEK prosthesis. Anterior implants showed a higher deformation and stress distribution when compared to posterior implants for all four prosthetic materials. Within the limitations of the study, metal-ceramic and Trinia showed less stress distribution, while metal-ceramic and PEEK exhibited less deformation on implant and its components. Hence in future, Trinia and PEEK along with metal-ceramic can be promising prosthetic materials of choice in full-mouth rehabilitation with implants. Considering the deformation and stress distribution on the implant and its components, the selection of prosthetic material in full-mouth rehabilitation has always been a challenge. Findings of the abovementioned cross-sectional observational study could give an overall insight into materials such as metal-ceramic and Trinia as materials of choice, which can provide a basis for future clinical trials.

Conventional osteotomy techniques can, in some cases, induce higher stress on bone during implant insertion as a result of higher torque. The aim of the present study was to evaluate and compare the stress exerted on the underlying osseous tissues during the insertion of a tapered implant using different osteotomy techniques through a dynamic finite element analysis which has been widely applied to study biomedical problems through computer-aided software. In three different types of osteotomy techniques, namely conventional (B1), bone tap (B2), and countersink (B3), five models and implants designed per technique were prepared, implant insertion was simulated, and stress exerted by the implant during each was evaluated. Comparison of stress scores on the cortical and cancellous bone at different time points and time intervals from initiation of insertion to the final placement of the implant was made. There was a highly statistically significant difference between B1 and B2 (p = 0.0001) and B2 and B3 (p = 0.0001) groups. In contrast, there was no statistically significant difference in the stress scores between B1 and B3 (p = 0.3080) groups at all time points of implant placement. Overall, a highly significant difference was observed between the stresses exerted in each technique. Within the limitations of our study, bone tap significantly exerted lesser stresses on the entire bone than conventional and countersink type of osteotomy procedures. Considering the stress distribution at the crestal region, the countersink showed lower values in comparison to others.

Introduction: Diseases affecting oro-facial structures can present themselves in a spectrum varying from pain like in case of acute pulpitis to psychosocial effects like in malocclusion. Poor malocclusion causes poorer oral aesthetic self-perception, and affects emotional and social well-being health domains. Aim: To assess the oral health related practices and status among college going students and to evaluate the effect of malocclusion on their quality of life. Materials and Methods: A cross-sectional study was conducted among 710 subjects of age range 17-23 years. Oral health status was assessed using WHO basic oral health survey (2013), orthodontic treatment needs according to Index of Orthodontic Treatment Needs (IOTN) and oral health quality of life using Oral Health Impact Profile-14 (OHIP-14). Mann-Whitney test and Fisher's-exact test were used for statistical analysis. Results: A total of 710 students were examined. It was seen that in the study population, only 290 (40.8%) knew that oral health affected general health and 501 (70.6%) had never visited dentist. The mean DMFT was 1.80+2.20 and 493 (69.4%) did not have any periodontal problem and 378 (53.2%) required orthodontic treatment ranging from little/mild to very severe orthodontic treatment need and it was seen that there was a difference in all the domains of OHIP-14 among the individuals in orthodontic treatment needed and not needed group and it was statistically very highly significant (p<0.001). Conclusion: It was seen that the study population had poor dental attendance. The orthodontic treatment need was also high as it should had been initiated at an early age for correction which in turn could improve the oral health related quality of life among the individuals who needed orthodontic treatment.