Influence of bonding agents on fracture force and fatigue performance of temporary fixed dental prostheses: an in vitro study.

OBJECTIVES

To investigate the influence of various bonding agents on the fatigue performance and fracture forces of temporary fixed dental prostheses (TFDPs).

METHOD AND MATERIALS: Temporary and permanent cements were used to lute TFDPs fabricated by CAD/CAM milling and digital light processing (DLP) printing. Thermocycling and mechanical loading (TCML) was conducted, simulating clinical service for a period of 2 years. Following TCML, all specimens were loaded until failure and fracture forces were measured. TFDPs after water storage (24 hours) were investigated as control. The following statistics (α = 0.95) were performed: Shapiro-Wilk test (Box-Cox transformation), Mann-Whitney U test (Holm correction), Fisher Exact test, Kaplan-Maier survival.

RESULTS

Milled TFDPs showed a survival rate of 100% for all cementations, while additively manufactured restorations featured survival rates between 0% and 63%. For additively fabricated TFDPs, temporary and conventional cements produced significantly (P ≤ .001) lower survival rates than self-adhesive or adhesive composite resins. Fracture forces after water storage ranged between 807 N and 2,287 N. After TCML, fracture forces ranged between 463 N and 1,738 N, with significant differences (P .05).

CONCLUSION

Additively manufactured TFDPs should be cemented self-adhesively or adhesively if intended for prolonged clinical service, while milled TFDPs might also be cemented temporarily to achieve a similar performance.