CAD/CAM to fabricate ceramic implant abutments and crowns: a preliminary in vitro study.

BACKGROUND This study evaluated the feasibility of fabricating implant abutments and crowns from pre-sintered feldspathic porcelain blocks using the chair-side CAD/CAM, CEREC3D((R)) system. METHODS Thirty-two implant analogues were divided into two groups. In the control group, prefabricated machined anatomical titanium (Ti) abutments were screw-retained to the analogues. In the test group, machined feldspathic porcelain abutments were cemented on prefabricated machined Ti links and screw-retained to the implant analogues. These feldspathic porcelain abutments were fabricated out of pre-sintered feldspathic porcelain blocks as duplicates of the abutments in the control group using the CAD/CAM, CEREC3D system. Thirty-two feldspathic porcelain crowns, also fabricated out of pre-sintered ceramic blocks, were then cemented with resin cement on all the abutments in both groups. All samples were subsequently subjected to fracture strength testing under static load. An unpaired t-test was used to compare fracture load values between the two groups. RESULTS The test group using feldspathic porcelain abutments and crowns showed statistically significant higher mean fracture strength than the control group with the Ti abutments and feldspathic porcelain crowns. CONCLUSIONS This preliminary study showed that the chair-side CAD/CAM technology can be utilized to fabricate customized ceramic abutments with their associated ceramic crowns using pre-sintered feldspathic porcelain blocks.