Clinical and radiographic evaluation of narrow-diameter titanium-zirconium implants in unilateral atrophic mandibular distal extensions: a 1-year pilot study.

BACKGROUND The use of endosseous dental implants has led to more sophisticated fxed options when considering treatment of patients with distal extensions. The use of narrow-diameter implants may reduce the necessity for bone augmentation. The mechanical strength of titanium is limited, so titanium alloys with greater tensile and fatigue strength may be preferable. PURPOSE The purpose of this study was to evaluate clinically and radiographically the performance of narrow-diameter bone level implants made from titanium-zirconium alloy (TiZr, Roxolid(TM)) in restoring unilateral atrophic mandibular distal extensions with fxed dental prostheses. MATERIALS AND METHODS Twenty partially edentulous patients with unilateral atrophic mandibular distal extensions received two 3.3 mm diameter bone level TiZr implants (Straumann AG, Basel, Switzerland). The two implants were restored with 3-units ceramo-metal fxed partial dentures. Standardized clinical and radiographic parameters (survival rate, probing pocket depth and marginal bone loss) were evaluated at the time of the completion of the prosthetic treatment (baseline) and after 3, 6 and 12 months of functional loading. Prosthetic complications were also assessed. RESULTS The survival rate for narrow-diameter bone level TiZr implants was 100% after 1 year of functional loading. There were no statistically significant differences between the values of probing pocket depth over the follow-up period. All implants showed less than 1 mm of marginal bone loss at the end of the follow-up period. CONCLUSION Within the limitations of this 1-year pilot study, the use of narrow-diameter bone level TiZr implants appears to be predictable in restoring the unilateral atrophic mandibular distal extensions. This type of implants meets established success and survival criteria after 1 year.