Prospective clinical-radiological study of the survival and behavior of short implants

Short implants are a therapeutic alternative for edentulous patients with severe bone resorption. Differences in peri-implant bone loss and complications of short implants depending on the type of connection are unclear.

The main purpose of this clinical study was to evaluate the survival rate after 2 years of the short implants in the Oxtein system (Proclinic). Secondary objectives were to compare implant survival, peri-implant bone loss, peri-implant mucosal status, and associated complications in internal hexagonal connection versus external hexagonal connection implants.

A randomized clinical trial was carried out in 14 patients with a mean age of 62.7 ±8.5 years, with a total of 61 Oxtein L35 and L6 Proclinic implants being placed at the Faculty of Dentistry. A descriptive analysis, simple binary logistic regression model using generalized estimating equations and Kaplan-Meier survival analysis were carried out (α=.05).

Implant survival was 85.2% (52/61). Failure of all implants occurred before prosthetic loading; bleeding after probing occurred in 28 implants, being greater among external connection implants (57.6%) P=.025. The presence of plaque appeared in 36 of the implants, without statistically significant differences between external connection (72.8%) and internal connection (60.0%) (P>.05). A total of 28 implants had at least 2 mm of keratinized mucosa, without statistically significant differences between external connection (63.6%) and internal connection (35.0%) P=.200. A total of 8 complications (13.1%) were recorded, including connection fractures, screw fracture, framework fracture, and buccal fenestrations.

Short implants are a therapeutic solution to more complex surgical techniques. However, as lower survival has been reported, the characteristics of the implants and operator experience are important factors for their success.