Clin Surg | Volume 6, Issue 1 | Research Article | Open Access

A 5-Years Report from a Multicenter Randomized Controlled Trial: Dental Implants with Conical Versus Internal Hex Connections

Tommaso Grandi1*, Maurizio Cannata2 and Rawad Samarani3

1Private Practice in Modena, Italy
2Private Practice in Rende (Cosenza), Italy
3Department of Periodontology, Saint-Joseph University, Beirut, Lebanon

*Correspondance to: Tommaso Grandi 

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Purpose: To compare implant failure, complications and radiographic bone level changes of dental implants with conical versus internal hex connections, 5 years after loading. Methods: A total of 90 patients with partial edentulous were selected and randomly divided into two equal groups (n=45) in order to be subjected to implant positioning either with conical connection or with internal hex connection at three dental offices. Patients were followed for a period of 5 years. Outcomes considered were implant failures, any complications and marginal bone level changes. Results: Three patients (6.7%) belonging to the conical group and one patient (2.2 %) belonging to the internal hex group dropped out. One implant (1.5%) failed in the conical group versus two implants (2.6%) in the internal hex group. There were no statistically significant differences in implant failures between the two groups (2.4% vs. 2.3%, difference 0.1%; 95% CI: -0.9; 5.1; p=0.584). Four complications occurred in the conical group and five in the internal hex group (9.5% vs. 11.4%, difference 1.9%; 95% CI: -0.7; 4.5; p=0.781). Five years after loading, patients in the conical group lost an average of 1.41 ± 0.94 peri-implant bone vs. 1.38 ± 0.89 mm for patients in the internal hex group with no significant differences between treatment group (p=0.745). Both treatment groups lost statistically significant marginal peri-implant bone at 5-year post-loading: P=0.0001 for both conical and internal hex group. Conclusion: No statistically or clinically significant differences were observed in outcomes 5 years after loading, between implants with conical and internal hex connection, hence clinicians can decide which type of connection to use according to their preferences.


Complication; Dental implant; Conical connection; Internal hex; Peri-implant marginal bone


Grandi T, Cannata M, Samarani R. A 5-Years Report from a Multicenter Randomized Controlled Trial: Dental Implants with Conical Versus Internal Hex Connections. Clin Surg. 2021; 6: 3322..

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