Effect of pattern fabrication methods on retentive strength in three‐unit implant‐supported frameworks: A comparative analysis

Objective Given the significant role of retention in the long‐term success of implant‐supported prostheses, this study aimed to compare the retentive strength of three‐unit implant‐supported frameworks manufactured using the conventional, subtractive milling, and 3D printing methods. Materials and Methods In this in vitro study, two fixture analogs were placed in the mandibular right first premolar and first molar region of a Dentiform model, and two prefabricated abutments were secured in the fixture analogs. A total of 27 three‐unit frameworks were fabricated utilizing wax patterns prepared through conventional, milling, and 3D printing techniques ( n = 9 per group). The frameworks were cemented with zinc oxide eugenol and subjected to thermocycling. The retentive strength of each specimen was evaluated through a pull‐out test conducted with a universal testing machine. The data were analysed using one‐way ANOVA and Tukey's post hoc test ( p < 0.05). Results The three groups were found to be significantly different ( p = 0.01). While the 3D printing and milling groups were not significantly different ( p = 0.99), they yielded significantly higher retentive strength compare to the conventional group ( p = 0.02 for 3D printing and p = 0.03 for milling group). Conclusion The utilization of 3D printing and milling technique for wax pattern preparation significantly increased the retention of the implant‐supported framework, with no statistically significant difference between the two methods.