Comparison of the Fracture Resistance of Provisional Crowns and Fixed Partial Dentures Manufactured with Conventional, Milling, and 3D-Printing Techniques

This study aimed to evaluate the effect of different manufacturing techniques and thermal aging on the fracture resistance of provisional crowns and fixed partial dentures. Methods: A total of 60 provisional crowns and 60 provisional fixed partial dentures were fabricated using three manufacturing techniques: conventional manufacturing (CM), subtractive manufacturing (SM), and additive manufacturing (AM). An index created from SM-manufactured restorations was used to produce the CM group. Artificial abutments were created by duplicating scanned phantom teeth using model resin. Half of the restorations (n = 10 per group) were subjected to thermal aging (5-55 degrees C, 5000 cycles). The fracture resistance values of the specimens were tested using a universal testing machine. Data were analyzed using a two-way ANOVA and Tukey's post hoc tests (alpha = 0.05). The highest mean fracture resistance was observed in the SM group without aging, both for crowns (1645.4 +/- 346.8 N) and fixed partial dentures (1291.13 +/- 564.15 N). The two-way ANOVA revealed statistically significant differences among the groups, and thermal aging significantly reduced the fracture resistance (p < 0.05). Both the manufacturing method and thermal aging significantly influenced the fracture resistance of provisional crowns and fixed partial dentures. In fixed partial dentures, a significant effect of aging was associated with the reduced durability of restorations fabricated using the subtractive manufacturing method.