DENTAL IMPLANTS WITH INTERNAL VERSUS EXTERNAL CONNECTIONS: 10-YEAR POST-LOADING RESULTS OF A PRAGMATIC MULTICENTRE RANDOMISED CONTROLLED TRIAL

PURPOSE. To compare the effectiveness of identical implants with internal or external connections. MATERIALS AND METHODS. One hundred and twenty patients with any type of edentulism (single tooth, partial or total edentulism) requiring one implant-supported prosthesis were randomly allocated at four centres to two equal groups to receive either implants with external connection (EC) or implants of the same type but with internal connection (IC) (EZ Plus, MegaGen Implant, Gyeongbuk, South Korea). Due to slight differences in implant design/components, IC implants were platform-switched while ECs were not. Patients were followed up for 10 years after initial loading. Outcome measures were: Any prosthesis/implant failures, complications, and marginal bone level changes, as assessed by blinded outcome assessors whenever possible. RESULTS. Sixty patients received 96 EC implants and 60 patients 107 IC implants. Eight patients from the EC group and nine from the IC group dropped out, but all remaining patients were followed up to 10 years post-loading. Two EC patients experienced implant and prosthesis failures versus three IC patients (P = 0.631, diff = 0.02, 95% CI: -0.07 to 0.11). Fifteen complications occurred in 13 EC patients versus 13 complications in 11 IC patients (P = 0.720, diff. = -0.03, 95%o CI: -0.19 to 0.13). There were no statistically significant differences for prosthesis and implant failures and complications between the different con-nection types. Ten years after loading, both groups had lost a significant amount of bone (1.01 mm at EC implants and 1.27 mm at IC implants), but there was no statistically signi-ficant difference in estimated marginal bone levels between the two groups (diff. = 0.07 mm, 95% CI: -0.41 to 0.54 mm, P (ANCOVA) = 0.782). CONCLUSIONS. Acknowledging the difference between EC and IC implants in terms of neck design and platform-switching, 10-year post-loading data revealed no statistically significant differences between the two connection types, and clinicians can therefore choose which they prefer. CONFLICT OF INTEREST STATEMENT. This trial was partially funded by MegaGen Implant, Gyeongbuk, South Korea, the manufacturer of the implants evaluated in this investigation. However, the resulting data belonged to the authors and by no means did the manufacturer interfere with the conduct of the trial or the publication of the results.