Fatigue resistance of 2 different CAD/CAM glass-ceramic materials used for single-tooth implant crowns.

PURPOSE

To evaluate the fatigue resistance of 2 different CAD/CAM in-office monoceramic materials with single-tooth implant-supported crowns in functional area.

MATERIALS AND METHODS

A metal experimental model with a dental implant was designed to receive in-office CAD/CAM-generated monoceramic crowns. Laterally positioned axial dynamic loading of 300 N at 2 Hz was applied to implant-supported crowns machined from 2 different glass materials for 100,000 cycle. Failures in terms of fracture, crack formation, and chipping were macroscopically recorded and microscopically evaluated.

RESULTS

Four of 10 aluminasilicate glass-ceramic crowns fractured at early loading cycles, the rest completed loading with a visible crack formation. Crack formation was recorded for 2 of 10 leucite glass-ceramic crowns. Others completed test without visible damage but fractured upon removal.

DISCUSSION

Lack in chemical adhesion between titanium abutment and dental cement likely reduces the fatigue resistance of machinable glass-ceramic materials. However, relatively better fractural strength of leucite glass-ceramics could be taken into consideration. Accordingly, progress on developmental changes in filler composition of glass-ceramics may be promising.

CONCLUSION

Machinable glass-ceramics do not possess sufficient fatigue resistance for single-tooth implant crowns in functional area.