Date of Completion


Embargo Period



Efthimia Ioannidou, Thomas Taylor

Field of Study

Dental Science


Master of Dental Science

Open Access

Open Access


Background: Implant supported mandibular overdentures (OVD) have been proposed as the gold standard for the treatment of edentulous mandibles. In addition, the use of immediate loading may reduce the treatment time and improve the patient comfort without jeopardizing implant success. Limited information is available on the clinical success of immediate loading of 2 unsplinted implants supporting a mandibular OVD. The purpose of this study was to evaluate clinically and radiographically the performance of 2 unsplinted implants supporting a mandibular OVD 12 months post surgical placement, using either an immediate or a delayed loading protocol.

Methods: Each patient received 2 implants 4.0mm diameter and length ranging from 8-15mm. Locator™ retained mandibular overdentures were connected to the implants either immediately (IL) or after 3 months of healing (DL). The main response variable was radiographic bone level change RBLC at 6 and 12 months. Patient was the statistical unit. Implant length, insertion torque value (IT), implant failure, prevalence of maintenance visits and prosthetic complications between the groups were also recorded.

Results: Thirty subjects 15 in the IL and 15 in the DL groups were available at 12 months evaluation. The cumulative implant success rate was 100% and 93% for DL and IL respectively. The mean RBLC from baseline to 1 year was 0.54 (±0.5) mm and 0.25 (±0.5) mm for DL and IL respectively. A statistically significant difference was observed at 12 months interval (p

Conclusions: Immediate loading of 2 unsplinted implants supporting a Locator™ retained mandibular OVD seems to be a suitable treatment option. A significantly smaller RBLC was observed after 1 year of loading on IL implants when compared to DL. However, this small difference may not be clinically relevant. Furthermore, in our sample neither implant length nor insertion torque value seemed have an effect on RBLC 1 year after surgical placement. Further studies are needed to confirm these results.

Major Advisor

Gian Pietro Schincaglia