ABSTRACT
PURPOSE: To compare the clinical and radiological outcomes of identical implants with conical or internal hex connections. METHODS: A total of 90 patients with partial edentulism requiring one implant-supported prosthesis were randomly allocated in two equal groups (nâ =â 45) to receive either implants with a conical connection or implants of the same type, but with an internal hex connection at three centres. Patients were followed for 1 year after loading. Outcome measures were implant failures, any complication and marginal bone level changes. RESULTS: One patient (2.2%) belonging to the internal hex group dropped out. One implant (2.2%) failed in the conical group. There were no statistically significant differences in implant failures between the two groups (2.2% vs. 0%, difference 2.2; 95% CI:â -1.3;â 5.7; Pâ =â 0.315). Two complications occurred in the conical group and two in the internal hex group (Pâ =â 1.000, differenceâ 0.00,â 95%â CI:â -3.1;â 3.1). The 12-month peri-implant bone resorption was similar in both groups: 0.56â ±â 0.53â mm (95%â CIâ 0.03;â 1.09) in the conical group and 0.60â ±â 0.62â mm (95%â CIâ 0.02;â 1.22) in the internal hex group (differenceâ =â 0.04â ±â 0.55, 95%â CI:â -0.51; 0.59,â Pâ =â 0.745). CONCLUSIONS: Within the limitation of this study, preliminary short-term data (1 year post-loading) did not show any statistical differences between the two internal connection types, therefore clinicians could choose whichever connection they prefer. Conflict of interest statement: Tommaso Grandi serves as consultant for Jâ Dentalâ Care, Modena, Italy. This study was completely self-financed and no funding was sought or obtained, not even in the form of free materials.