Effect of Cervical Margin Relocation With Different Injectable Restorative Materials on Fracture Resistance of Molars Received MOD CAD/CAM Onlay Restorations.

OBJECTIVE

To investigate the effect of cervical margin relocation with four different injectable restorative materials on the fracture resistance of molars receiving mesio-occluso-distal CAD/CAM nanoceramic onlay restorations.

MATERIALS AND

METHODS

One hundred and five sound mandibular molars received a standardized mesio-occluso-distal onlay preparation, with cervical margins located 2 mm apical to the cemento-enamel junction. The molars were randomly allocated into five groups (n = 21) according to the cervical relocating materials used: Group I had no cervical margin relocation; Group II used a highly viscous glass ionomer; Group III used a highly-filled injectable resin composite; Group IV used a resin-modified glass ionomer; and Group V used a bioactive ionic resin. All groups received immediate dentin sealing before nanoceramic resin-based CAD/CAM onlay restorations. After the specimens were subjected to thermo-mechanical loading, they underwent fracture resistance testing and failure mode analysis.

RESULTS

No statistically significant difference in fracture resistance was observed among the tested groups. Regarding the mode of failure, irreparable failure was significantly dominant, with no significant difference among the groups.

CONCLUSION

Employing injectable restorative materials for cervical margin relocation had no detrimental effect on the fracture resistance of molars receiving nanoceramic resin-based CAD/CAM onlay restorations.

CLINICAL SIGNIFICANCE: CAD/CAM onlay restorations preceded by cervical margin relocation using injectable restorative materials could tolerate compressive loading comparably to those without cervical margin relocation.