Retention of telescopic versus LOCATOR attachments and marginal bone loss surrounding implant-retained maxillary overdentures: A 2-year randomized clinical trial.

STATEMENT OF PROBLEM: A maxillary implant-retained overdenture (Max IOD) represents a controversial prosthesis. Biomechanically, the prosthesis induces strain on the implants, associated with complications from maintenance difficulties to implant loss. Whether the choice of attachment system affects retention of the prosthesis and marginal bone loss (MBL) around the implants remains unclear.

PURPOSE: The purpose of this clinical trial was to assess the amount of retention and MBL provided by 2 attachment types: telescopic (TA) and LOCATOR (LA).

MATERIAL AND

METHODS

Forty participants (24 women and 16 men) with completely edentulous maxillas and mandibles were enrolled. Each participant received a two-implant-retained mandibular overdenture and a four-implant-retained Max IOD and was randomly divided into two groups based on the attachments that retained the Max IOD (TA or LA). At baseline, 1 month after delivery (R0), retention and MBL (vertical and horizontal) surrounding the dental implants were measured for both groups at 12 months (R12) and at 24 months (R24) after the insertion of the prostheses. A two-arm, parallel-group randomized controlled trial (RCT) was conducted using a 1:1 allocation ratio. The Kolmogorov-Smirnov test was used to verify the standard assumption for numerical data. The research groups were compared using the Student t test for independent samples. A paired t test was used to compare numerical variables within groups. Any comparison involving more than two time points was subject to the Bonferroni adjustment of multiple comparisons (α=.05).

RESULTS

A significant difference was found in the retention of the two groups throughout all follow-up periods (P<.001), with the TA overdenture showing higher values when compared with the LA overdenture. The TA group was associated with higher vertical and horizontal MBL than the LA group, with a significant difference at R12 and R24 (P<.001).

CONCLUSIONS

The TA was found to be a more retentive option for Max IODs than the LA attachment. However, the LA group showed less MBL around implants than the TA group over 2 years. These findings suggest that TA and LA attachments can be suitable for retaining maxillary implant overdentures, as the MBL around both groups remained within acceptable levels.