Loading capacity of CAD/CAM-fabricated anterior feldspathic ceramic crowns bonded to one-piece zirconia implants with different cements.

Abstract

This study evaluated the loading capacity of CAD/CAM-fabricated anterior feldspathic ceramic crowns bonded to one-piece zirconia implants with different cements. Fifty one-piece zirconia implants were embedded in epoxy resin. The abutment aspect of one implant was optically scanned and a standardized upper canine was designed with CAD-software. Fifty feldspathic ceramic crowns were milled, polished, and mounted on the implants either without any cement, with a temporary cement or with three different composite resin cements after surface pretreatment as recommended by the manufacturers (n=10). After storage in distilled water at 37°C for 24hr, specimens were loaded until fracture on the palatal surface of the crown at an angle of 45° to the long axis of the implant and loads until fracture were detected and compared. Compressive strength of the investigated cement materials was determined. Statistical analyses were done with One-way ANOVA followed by post hoc Fisher LSD test (α=0.05). The cements revealed significantly different compressive strength values (temporary cement: 37.1±7.0MPa; composite resin cements: 185.8±21.3, 277.9±22.1, and 389.0±13.6MPa, respectively). Load-at-fracture values had an overall mean value of 237.1±58.2N with no significant difference among the composite resin cements (p>0.05). Fracture load values with the temporary cement or without cement were significantly lower (p<0.002). CAD/CAM-fabricated anterior feldspathic ceramic crowns bonded to one-piece zirconia implants provide sufficient resistance to intraoral forces.