Five-Year Clinical Evaluation of 117 Prostheses Supported by
a Standard Abutment and Implant Placed via a Single Stage Protocol
Kwan, Norman; Yang, Silvia: Canadian Dental Implant Institute, 206 King Street, St. Catharines, ON, L2R 3J7, Canada Weiner, Saul; Aboyoussef, Hoda; Zweig, Barry; Thompson, Van; University of Medicine & Dentistry of New Jersey, 110 Bergen Street, University Heights, Newark, NJ, 07103, USA

A standard 3 mm hexagonally-shaped titanium abutment was pre-attached to a screw type implant and surgically inserted as one integral unit. Because the abutment protrudes through the mucosa, a second surgery was not required. 374 of these integral implant units were placed in 107 consecutive patients. A total of 117 prostheses were evaluated over 60 months. With the exception of two, all failed implants occurred within three months after placement and before insertion of prosthesis. Cumulative probability of survival was 89.7 % (Kaplan-Meier analysis) over five years.Clinical parameters including bone loss, pocket depth, attached epithelium, plaque index, mobility and pain were evaluated.

Prosthetic complications such as screw loosening and fractured components were also recorded.20 out of 36 restorations were cement-retained single crowns, and the remaining 16 crowns were screw-retained. One crown was lost after 4 years due to a fractured abutment screw. No other prosthetic complications were observed. 81 prostheses were supported by multiple implants, 33 of which were cemented while the other 48 were screw-retained. Only two implants failed after insertion of the final prosthesis and did not affect the overall restoration.The implication of this study indicates that a standardized abutment can be successfully used to restore all edentulous and partially edentulous cases.

1. Buser D, Wever HP, Lang: Tissue Integrated on Non-Submerged Implants. One Year Results of a Prospective Study with 100 ITI Hollow-Screw and Hollow Cylinder Implants. Clinical Oral Implants Res 1990; 1:33-40.
2. Bernard J-P, Belser UC, Martinet JP, Borgis SA.: Osseointegration of Branemark Fixtures Using a Single-step Operating Technique. A Preliminary Prospective One-year Study in the Edentulous Mandible. Clin Oral Implants Res 1995;6:122-129.

This research is supported by Biomedical Implant Technology Inc.