Objectives: To evaluate and to compare the effect of the conical neck design on marginal bone loss around the fixtures, when both implants were provided with micro-threads to the top of the fixture.
Materials and methods: Two types of implant, one with a straight shape (S) and the other with a conical neck design (C) provided with a retentive element to the top of the fixture, were placed adjacent to each other in the partially edentulous areas of 12 patients. Bone loss around each implant was analyzed after 1 year of functional loading. The bone losses after loading were compared using Wilcoxon's signed-rank test.
Results: The mean marginal bone losses (S, 0.05 + or - 0.09 mm; C, 0.07 + or - 0.14 mm) were not statistically significant between the two groups (P=0.578).
Conclusions: There was no significant difference between conical and straight neck implants in terms of marginal bone loss after 1 year of loading.