Inside Dentistry
Jul/Aug 2006
Volume 2, Issue 6

Simplified methods of implant treatment in the edentulous lower jaw: a 3-year follow-up reportof a controlled prospective study of one-stage versus two-stagesurgery and early loading

Howard E. Strassler, DMD

Engquist B, Åstrand P, Anzén B, et al. Clin Implant Dent Relat Res. 2005;7(2):95-104.


Background: Interest in the use of one-stage surgery and immediate loading of oral implants has lately been increasing. Purpose: The aim of this study was to compare the 3-year results of one-stage surgery versus two-stage surgery, early loading versus loading after a 3-month healing period, and the use of one-piece implants versus the use of two-piece implant. Materials and Methods: The study included 108 patients with edentulous mandibles. Each patient was treated with four Brånemark System® implants (Nobel Biocare AB, Göteborg, Sweden) and full fixed prostheses. Patients were consecutively treated and were distributed in four groups: group A (one-stage surgery), group B (control group with two-stage surgery, group C (one-piece implants) and group D (early loading). In groups A and B, Brånemark Standard implants and standard abutments were used. In group C, the conical one-piece Brånemark was used, and in group D the patients had Brånemark System Mk III implants together with multiunit abutments. All patients were observed for 3 years. Results: Of the 432 inserted implants, 24 were lost. Survival rates in the three experimental groups ranged from 93.2% to 93.3% whereas the survival rate in group B (the control group with two-stage surgery) was 97.5%. The differences between the groups were not statistically significant. The changes in marginal bone level were measured from the fixture insertion to the final follow-up at 3 years. The bone loss in group D (early loading) was significantly less than in group B (the control group) whereas there were no differences in marginal bone change between other groups. Conclusions: Early loading seemed to give good results in the anterior part of the mandible. The survival rate of the early-loaded implants did not significantly differ from that of implants inserted with the conventional two-stage procedure, but the mean marginal loss around the surviving implants was less with early loading.


In patients edentulous in the lower jaw for extended lengths of time, the resorption of the ridge makes mandibular denture retentions a challenge. Successes with implants have created a standard of care for mandibular denture retention that includes the placement of an implant-supported denture. Disadvantages of implant treatment of the edentulous and partially edentulous jaws include long treatment periods and high costs in the short run. This study investigates the use of one-stage surgery and immediate loading to address these disadvantages. The design was well conceived in addressing the questions of immediate loading and one-stage placement. Based on the results, although the survival rates of the implants showed a tendency toward better results with the two-stage technique, the differences were not significant. Of the 24 implants lost, seven of these were lost before loading. Based on this study, the use of a one-stage surgery with immediate loading can be expected to produce excellent results in retaining full fixed prostheses for the edentulous mandible.

About the Author

Howard E. Strassler, DMD
Professor and Director of Operative Dentistry
Department of Endodontics, Prosthodontics and Operative Dentistry
University of Maryland Dental School, Baltimore, Maryland
Email: hstrassler@umaryland.edu

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