An evaluation of the fracture resistance of class 2 amalgam restorations with different cavity designs on maxillary premolars

[摘要] Aims and Objectives: The aim of this work was to compare the fracture resistance values of «DQ»Mesio-occlusal«DQ» preparation, «DQ»slot«DQ» preparation with «DQ»conventional grooves,«DQ» «DQ»box-only,«DQ» and «DQ»MOD«DQ» preparation. Materials and Methods: A total of 60, noncarious extracted maxillary premolars were selected and divided into four groups, consisting of 15 teeth each -- group A: «DQ»Mesio-occlusal«DQ» preparation, group B: «DQ»slot«DQ» preparation (conventional grooves), group C: «DQ»box-only«DQ» preparation (long grooves), group D: «DQ»MOD«DQ» cavity preparation. All the specimens were subjected to compressive axial load in triaxial testing machine at a cross head speed of 1.2 mm/min at an inclination of 13.5°. Results: Group A («DQ»Mesio-occlusal«DQ») preparation had the least fracture resistance value and group D («DQ»MOD«DQ») cavity preparation had the highest fracture resistance. There was a significant difference in fracture load found between groups B and C. Conclusion: Amalgam restorations with «DQ»Mesio-occlusal«DQ» preparations had the least fracture resistance. Amalgam restorations with «DQ»slot«DQ» preparations had better fracture resistance than «DQ»box-only«DQ» preparation. Amalgam restorations with «DQ»MOD«DQ» preparations had the highest fracture resistance.

[关键词] Amalgam;class 2 designs;fracture resistance aggregate;perforation repair