A 5-Year Randomized Trial to Compare 1 or 2 Implants for Implant Overdentures

Abstract

The hypothesis of this 5-y randomized clinical trial was that there would be no significant difference in the satisfaction of edentulous participants with removable complete overdentures attached to 1 or 2 mandibular implants. Secondary aims were to test changes in satisfaction between and within the groups from baseline to 5 y and differences between the groups in implant survival and prosthodontic maintenance over 5 y. Each of the 86 participants (mean age, 67 y) was randomly allocated to receive either 1 implant in the midline (group 1) or 2 implants in the canine areas (group 2) attached to a mandibular overdenture opposing a maxillary complete denture. Satisfaction was self-assessed by participants on a visual analog scale at baseline prior to implants, as well as at 2 mo and 1, 3, and 5 y with implant overdentures, whereas implant survival and prosthodontic maintenance were assessed by clinical examination. After 5 y, 29 participants in group 1 and 33 in group 2 were available, with most dropouts due to death. Satisfaction with the implant denture after 5 y was significantly (P < 0.001) higher than at baseline in both groups and remained with no significant difference (P = 0.32) between the groups. No implants failed in group 1 but 5 failed before loading in 4 participants in group 2. Most participants required maintenance or occasionally denture replacement, and although differences between the groups were not statistically significant, group 1 experienced almost twice as many fractured dentures usually adjacent to the implant attachment. We conclude that there were no significant differences after 5 y in satisfaction or survival of implants with mandibular overdentures retained by 1 implant or 2 implants. Additional research is required to confirm long-term treatment effectiveness of single-implant dentures and the implications of prosthetic maintenance with implant overdentures (ClinicalTrials.gov: NCT02117856).

The Influence of Implant Number on Peri-Implant Marginal Bone Level and Implant Failures in Mandibular Implant Overdentures. A Systematic Review With Meta-Analysis.

“…The selected nine studies 6,[27][28][29][30][31][32][33][34] were RCTs and were published between 1998 to 2016. The observation period ranged from 12 months to 10 years.…”

“…All of the studies were conducted in a university setting; four trials were conducted in Netherlands [27][28][29][30] , two studies in Canada 33,34 two studies in Egypt 31,32 and one in Germany 6 . Six studies reported delayed loading protocol [27][28][29][30][31][32] while the other three studies 6,33,34 followed an early/immediate loading protocol. In early loading protocol, the dentures were inserted 42 days after implant placement 33 whereas in immediate loading protocol the denture were inserted at time of surgical implant placement 1329 34 .…”

“…Six studies reported delayed loading protocol [27][28][29][30][31][32] while the other three studies 6,33,34 followed an early/immediate loading protocol. In early loading protocol, the dentures were inserted 42 days after implant placement 33 whereas in immediate loading protocol the denture were inserted at time of surgical implant placement 1329 34 . In one study 6 , soft liner material was used in the first 6 weeks after surgery and the authors described it as a progressive or an early loading protocol.…”

“…In one study 6 , soft liner material was used in the first 6 weeks after surgery and the authors described it as a progressive or an early loading protocol. Data on the peri-implant marginal bone level changes was reported in six studies 6,27,28,[30][31][32] , whereas the number of implant failures was extracted from all of the included studies 6,[27][28][29][30][31][32][33][34] .…”

“…kronstrom et al 34 corresponding to (Kronstrom et al 38 ). Bryant et al 33 corresponding to (Walton et al…”