Evaluation of Shear Bond Strength of Bilayered All Ceramics Systems with Finite Element and Acoustic Emission Analysis

S12 The Journal of Indian Prosthodontic Society | Volume 20 | Supplement 1 | December 2020 bar & clip attachment and the lowest stresses were obtained through locator attachment. DOI: 10.4103/0972-4052.306330 Evaluation of Shear Bond Strength of Bilayered All Ceramics Systems with Finite Element and Acoustic Emission Analysis Dr. Sivaranjani Gali M.S. Ramaiah Dental College,Karnataka Introduction: All-ceramics systems have gained remarkable interest, amongst the metal free ceramic systems, due to their superior mechanical properties. However, veneer fractures and chipping in bilayered ceramic restorations present a major limitation. Methodology: Shear bond strength of commercially available core ceramics to veneering ceramics along with an experimental zirconia mica glass ceramics was evaluated. In addition, the interfacial core-veneer stresses were estimated using finite element modelling and co-related the results of shear bond strength with acoustic emission analysis. Three dimensional finite element models of ceramic core-veneer were modelled to simulate the experimental shear bond strength tests. Shear bond strength between core-veneer specimens were tested with a universal testing machine at a cross-head speed of 1mm/ min with acoustic emission (AE) sensors to investigate the material response such as fracture initiation and propagation. Result: High shear bond strength were observed in IPS e.max Press-IPS e.max Ceram with cohesive core fractures followed by Zirconia-IPS e.max Ceram with mixed mode fractures. Conclusion: Interfacial reactive bonding between glass ceramics of IPS e.max Press and IPS e.max Ceram direct the promotion of fusion glass-ceramic in zirconia bilayered restorations. DOI: 10.4103/0972-4052.306331 Clinical, Electromyographical and Radiological comparison of Dawson’s bimanual technique of guiding the mandible with Wax ball orientation technique© Dr. Sushma R School of Dental Sciences, Krishna Institute of Medical Sciences, Karad Introduction: To compare and assess which amongst the two centric relation guiding techniques best guides the mandible to centric relation position using clinical, myographical and radiological assessment methods. Methodology: The study was conducted as a randomized controlled trial on dentate subjects aged between 18 to 25 years of age with Angle’s class I occlusion. The study was carried out in 3 phases; Clinical, Electromyography, Radiological. Difference between the centric points, workload on elevators, condylar position was assessed. Result: Descriptive statistics was used to analyze the difference between the centric points marked using both the techniques. When independent ttest was applied to correlate the gender and mean centric distribution, no statistically significance difference was observed. Paired t test showed that workload on elevators of both sides, difference between the anteroposterior and superoinferior positions of condyle in relation to the fossa was statistically insignificant. Multivariate test showed statistically significant difference between gender and EMG, results whereas it was insignificant in MRI. Conclusion: The results of the study can safely claim that the wax ball technique is more or less as accurate as the Dawson’s bimanual technique. DOI: 10.4103/0972-4052.306332 Influence of ultrasonic procedures on different luting agents on marginal discrepancy of indirect restorations Dr. Srinivas Rao Pottem Narayana Dental College & Hospital,Nellore Introduction: The relationship between margins Vs plaque retention was very well documented furthermore, risk of secondary complications was elaborated in literature and suggested for routine follow-up & oral prophylaxis. Some investigators evaluated the effects of ultrasonic procedures on restorative materials, but the discrepancy of luting agent at the tooth and restoration interface of indirect restorations has not yet documented. Else this study was performed to evaluate the influence of peizoelectric ultrasonic procedures on marginal integrity of indirect restorations bonded with different luting agents.