A Prospective Randomized Clinical Study to Evaluate Outcomes of Treatment with Mandibular Implant Overdentures Supported by a Single Parallel-Walled or Tapered Titanium Dental Implant Placed According to the Immediate Loading Protocol: A 12-Month Follow-up Report.

PURPOSE: To evaluate clinical outcomes among subjects with mandibular overdentures supported by a single parallelwalled or tapered dental implant placed according to the immediate loading protocol.

MATERIALS AND

METHODS

Fortyseven edentulous subjects (21 men and 26 women; mean age: 61.5 years) with dentures fulfilled the criteria for inclusion and were scheduled for surgical implant placement. All subjects were provided with a single implant in the mandibular symphyseal area, after which a Locator abutment was connected to the implant immediately following placement. The mandibular denture was modified and provided with the attachment insert component and delivered the day of implant surgery. The subjects were scheduled for follow-up examinations 6 and 12 months after implant placement and yearly for another 4 years. Yearly examinations included a periapical radiograph to determine peri-implant bone level and clinical evaluation of denture stability, retention, wear, occlusion, and mucosal health.

RESULTS

Seven subjects were excluded during the first year: Two could not be reached and were lost to follow-up, one had died, three had failing implants, and one requested to have the implant removed. A total of 40 of the 47 subjects (19 men and 21 women; mean age: 64.1 years) were available for the 12-month follow-up. The parallel-walled implant group (Group 1) included 20 subjects (8 men and 12 women), and the tapered implant group (Group 2) included 20 subjects (11 men and 9 women). The mean peri-implant bone change was 0.29 mm (range: 0 to 1.8 mm), and the implant stability quotient remained stable, with no significant differences between the groups. The most common need for maintenance was replacement of the retentive nylon attachment insert.

CONCLUSIONS

No significant differences were found between subjects in the two groups with respect to implant survival rates and peri-implant bone loss. Need for denture maintenance was mostly related to the replacement of retentive nylon caps.