Effect of Cementation Technique Applied for Single-tooth Implant Crowns on Residual Cement: A Three-arm Parallel-group Randomized Clinical Trial

Single-tooth implant crowns to replace missing molar tooth were addressed to qualify and quantify residual cement on implant-abutment complex and peri-implant soft tissue following cementation. Thirty bone-level dental implants of one kind enrolled in the study. Prior to delivery of screw-retained crowns completed for usual treatment, implants were allocated randomly to a trial comparison group. Three different cement loading approach, ten in each group, was applied using cement-retained trial crowns on prefabricated metal abutments. Following completion of the assigned cementation technique, the trial crown was removed with its abutment accessing from the occlusal hole prepared after removal of excess cement. Then, the presence of residual cement on implant-abutment complex and implant soft tissue in accordance with axial and proximal surfaces was qualified. To quantify the amount of residual cement in accordance with location and distribution, the crown-abutment complex was digitized three-dimensionally using an intra-oral scanner. The output of surface data was evaluated in virtual 3-D image for cement excess, when detected location in the abutment-crown complex is recorded, area and distribution was calculated using a software. The frequency of occurrence and quantity of residual cement of 3-different cementation techniques was statistically evaluated using logistic and linear regression model separately considering abutment margin, crown surface and contour.