STRAINS INDUCED BY ZIRCONIA AND METAL RESIN BONDED ATTACHMENTS VERSUS EXTRACORONAL ATTACHMENT WITH FULL VENEER RETAINER IN MAXILLARY DISTAL EXTENSION REMOVABLE PARTIAL DENTURES

Document Type : Original Article

Authors

1 Lecturer, Removable Prosthodontics Department, Faculty of Oral and Dental Medicine, Misr International University

2 Associate Professor, Removable Prosthodontics Department, Faculty of Oral and Dental Medicine, Misr International University.

Abstract

Aim of the study: The aim of this study was to assess the strains transferred by zirconia and metal resin-bonded attachments (RBAs) to the maxillary distal extension removable partial denture (RPD) supporting structures and compare them with the strains generated by the extracoronal attachment with full veneer retainers. Materials and Methods: Three identical partially edentulous models that were created with a 3D printing technology. The virtual models for the retainers and the three attachments were designed using digital software. Model (1): Zirconia resin-bonded attachment (ZRBA). Model (2): Metal resin-bonded attachment (MRBA). Model (3): Extracoronal attachment with full veneer metal ceramic retainer (ECFV). Using 3D printing technology, the wax patterns for the three types of attachments were printed, and the retainers were constructed and cemented on their models. This was followed by the fabrication of attachment-retained removable partial dentures on the three printed models. Each RPD was subjected to a compressive static load of 100N using a universal testing machine. Then the strain values were recorded. Results: On bilateral loading, there were significant differences in the recorded strains at the three strain gauge locations between RBAs and ECFV. During unilateral loading, the results revealed statistically significant differences between the three attachments at the loading and non-loading sides. Conclusion: In distal extension maxillary RPD, there is no significant difference between the strains generated by zirconia and metal resin bonded attachments. While the extracoronal attachment with full veneer retainers applied less strains on RPD supporting structures than resin bonded attachments.

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