EVALUATION OF FRACTURE RESISTANCE OF 3D-PRINTED IMPLANT RETAINED OVERDENTURE WITH TWO DIFFERENT BUILD ANGLES. (AN IN-VITRO STUDY )

Abstract

Aim: The aim of this in-vitro study was to evaluate the influence of different build-angles on the fracture resistance of implant-retained 3D-printed overdentures fabricated with100 0 and a 150 0 build-angles. Methodology: A ready-made resin full edentulous mandibular model was used with two implant inserted in interforaminal region. Optical scanning for the model with implant was done in order to construct standard tessellation language (STL) file and design an implant overdenture. Then, 3D printing was done using digital light processing (DLP) printer with two different build angle(100 0 and 150 0).The fracture resistance was measured; by applying vertical forces at different points (one at anterior region and two at first molar region bilaterally) in the first group with overdentures printed with a 100 0 build angle while in the second group the overdentures which fabricated with a 150 0 build angle using Universal testing machine after being subjected to cycling load for 240000 cycle in chewing simulator machine. Results: S1 and S2 presented maximum load at failure of 1409 N and 846 N, respectively, and S3 and S4 presented maximum load at failure of 2164 N and 2206 N, respectively. There was no statistically significant difference between fracture resistance values of 100º (S1 and S2) and 150º (S3 and S4) build angles. Conclusion: Both build-angles proved to have acceptable mechanical properties. Although there was no statistical significance difference between the two groups, the results showed higher values in 150 0 build angle compared to 100 0 build angle group.