Evaluation of Stability Changes in Tapered and Parallel Wall Implants: A Human Clinical Trial

To determine the pattern of stability changes as a reflection of earlyhealing around single-stage roughened-surface implants in humans utilizing resonancefrequency analysis (RFA).Materials and Methods: Hundred twenty-five patients who demanded dentalimplants were treated with two different implant (Nobel Biocare ReplaceTM andStrummanTM ITI) systems. Bone type was classified into four groups. RFA wasused for direct measurement of implant stability on the day of implant placementand consecutively at 14, 30 and 60 days after placement. The data were analyzedwith Student t test and regression analysis.Results: Three-hundred four roughened surface implants placed in the maxillaand mandible were evaluated. In ReplaceTM implants the lowest mean stabilitymeasurement was at 30 days for all bone types and the stability did not changesignificantly in any of the bone types (p>0.05). ITITM implants demonstrated thelowest stability at 60 days for type 1 and 30 days and baseline for type 2, 3 and 4bones. In addition, there was significant differences in implant stability betweenbone types 1 and 4 (P<0.001), 2 and 3 (p<0.05) , and bone types 3 and 4(P=0.07) at all aforementioned times in ITITM implants. In ReplaceTM implants,regarding the implant diameter, contrary to ITI implants, no significant stabilitychanges were detected (p>0.05). No significant difference was observed regardinggender, age and lengths in both systems.Conclusion: In comparison to ITITM implants, ReplaceTM implants revealed nosignificant difference in the pattern of stability changes among different bonetypes.