Influence of connector dimensions on the stress distribution of monolithic zirconia and lithium-di-silicate inlay retained fixed dental prostheses e A 3D finite element analysis

Purpose: The objective of the study was to analyze the stress distribution between monolithic Lithium-disilicate and monolithic Zirconia inlay retained Fixed Dental Prostheses by varying the connector dimensions using the 3D- Finite Element Analysis. Methods: Two models of three unit inlay retained Fixed Dental Prosthesis replacing the lower right first molar was fabricated, each with the connector dimensions of 3 mm x 3 mm and 4 mm x 4 mm. Using three dimensional Finite Element Analysis, the Poisson s ratio and Young s modulus for monolithic Zirconia and monolithic Lithium-di-silicate were added to each of these groups. These were then subjected to a vertical load of 500 N directed occlusally over a surface area of 5 mm^2; and the results were analyzed. Results: By increasing the connector dimensions up to 4 mm x 4 mm, both the materials are capable of withstanding a force of up to 500 N, simulating the maximum posterior bite force. According to this study, monolithic Zirconia and Lithium-di-silicate can be used a posterior restorative material in all ceramic inlay retained Fixed Dental Prosthesis. Conclusion: Increasing the connector dimensions up to 4 mm x 4 mm, has a significant improvement in the stress distribution among both materials, making it suitable as a posterior restorative material in all ceramic inlay retained Fixed Dental Prosthesis. Further long term clinical studies are required.