Odontology. 2025 Nov 29. doi: 10.1007/s10266-025-01263-6. Online ahead of print.
ABSTRACT
To investigate the fracture and apparent flexural strength at fracture of three-unit implant-supported bridge restorations at different connector cross-sectional areas according to material type, produced on ti-base abutments using the CAD-CAM system. A total of 42 three-unit implant-supported bridge restorations were designed digitally (maxillary canine and second premolar as abutment and 1st premolar as a pontic). Two main groups (N = 21) were created to be manufactured from monolithic zirconia and lithium disilicate. Then, each group was divided into three subgroups (n = 7) according to the connector cross-sectional area (9 mm2, 12 mm2, 15 mm2 for monolithic zirconia; 12 mm2, 16 mm2, 20 mm2 for lithium disilicate). The samples were subjected to a fracture test on a universal testing machine and the values obtained were formulated to calculate the apparent flexural strength at fracture. In terms of fracture strength, there were statistically significant differences for both monolithic zirconia and lithium disilicate (p < 0.001, p < 0.001, respectively). In terms of apparent flexural strength at fracture, there were statistically significant differences for both monolithic zirconia and lithium disilicate (p = 0.012, p = 0.007, respectively). When monolithic zirconia and lithium disilicate samples with a common connector cross-sectional area (12 mm2) were compared, it was found that monolithic zirconia was statistically significantly stronger (p = 0.002). Under the present static test conditions, monolithic zirconia can be used as three-unit bridges safely in the premolar region. Lithium disilicate can also be used as three-unit bridges in the premolar region; in cases where there is sufficient connector area and the patient does not have parafunctional habits. As a result, increasing the connector cross-sectional area increases the strength significantly (p < 0.05).
PMID:41318837 | DOI:10.1007/s10266-025-01263-6
