Clinical effectiveness of rubber dam and gingival displacement cord with copy abutment on reducing residual cement for cement- retained implant crowns

Abstract

Background : One of the biggest disadvantage of cement- retained implant prosthesis is the difficulty to completely eliminate excess cement left after prosthesis cementation on the implant abutment. Many clinicians prefer cement- retained suprastructures on implants. There are several methods suggesting how to control or reduce subgingival residual cement around implant retained restorations such as using abutment replicas, gingival displacement cord or rubber dam. Aim/Hypothesis : Aim- to evaluate the amount of undetected residual cement after cementation and cleaning on cement- retained implant crown surfaces using rubber dam and gingival displacement cord with copy abutment. Null hypothesis- there is no difference between both methods used. Material and Methods : 15 single posterior cement- retained metal- ceramic implant- supported restorations were delivered for nine patients. Crowns were fabricated with occlusal openings and luted with resin- reinforced glass- ionomer on customized abutments with the circular 1 mm subgingival margin. Occlusal openings were obturated with composite and cementation procedure was applied two times- using rub- ber dam and then retraction cord with copy abutment. After cleaning the excess cement, periapical radiograph was taken. Only if no cement remnants were shown in radiograph, crown abutment unit was dismounted for inspection of undetected excess cement. Cemented supras- tructures were sent to dental technician laboratory to separate crowns from abutments and clean all the luting agent. Then second cementing procedure was applied. All quadrants of specimens were photographed for calculation of the ratio between the cement remnants area and the total specimen area using Adobe Photoshop, resulting in 120 measurements. Results : Comparing two different luting procedures – using rubber dam (group 1) and gingival displacement cord with copy abutment (group 2), total 60 measu[...].