Clinical outcomes of single implant supported crowns versus 3-unit implant-supported fixed dental prostheses in Dubai Health Authority: a retrospective study

Abstract

Background This study assessed retrospectively the clinical outcomes of single implant-supported crowns and implant-supported fixed dental prostheses (FDPs). Methods This case series compared biological and technical complications in single implant-supported crowns and implant-supported bridges in a time framed sample of all patients who received dental implants between 2009 and 2016 in Dubai Health Authority. Only 3-unit implant-supported prostheses (FDPs) with one intervening pontic and an implant each end were included for comparison to single crown supported implants. Cantilevered implants, implant-supported dentures and cases involving bone grafts or sinus lifts were excluded. The primary outcome measure was marginal bone loss, measured on digital radiographs taken after prosthesis placement at baseline and one year after implant loading, whilst peri-implantitis and technical complications were secondary outcomes. Mixed regression models adjusted for clustering of implants within patients was used for patient and implant factor associations. Results A total of 454 patients (152 males; 302 females) had 1673 implants. The mean age of males (53.7 years, SD 14.6) was significantly greater than females (49.3 years, SD 12.9, p < 0.001). Mean mesial bone loss on the FDPs was significantly greater at 1 year (1.14 mm, SD 0.63) compared with the mesial surface of single implant-supported crowns (0.30 mm, SD 0.43, p < 0.001). Mean distal bone loss was also significantly greater at 1 year on the distal surfaces of implants supporting bridgework (1.29 mm, SD 0.71) compared with distal surfaces on single implant-supported crowns (0.36 mm, SD 0.54, p < 0.001). Mean marginal bone loss mesially and distally around implants placed in the lower anterior sextant was significantly greater compared to all other sites (p < 0.001). Bone loss by gender, patient’s age and medical condition was not different between the 2 implant groups. Screw loosening was the main technical complication (11.5%) whilst peri-implantitis occurred rarely (0.5%). The 66 cement retained implants had significantly more complications compared to the 1607 screw retained implants (p < 0.001). Conclusions Mean marginal bone loss around the supporting implants of FDPs (3-unit fixed bridgework) was greater than on single implant-supported crowns at one year after implant loading. Position in the mouth was associated with bone loss. Biological and technical complications occurred rarely.

A retrospective comparison of clinical outcomes of implant restorations for posterior edentulous area: 3-unit bridge supported by 2 implants vs 3 splinted implant-supported crowns

“…The findings of the present study were not consistent with that of Alhammadi et al 20 who reported implants supporting 3-unit fixed bridge showed greater marginal bone loss and more frequent technical complications than single implants. This difference may be attributed to the fact that variables such as diameters or lengths of the implant were not included in their study although they included not only posterior but also anterior implant fixed restorations.…”

Long-term effect of implant-abutment connection type on marginal bone loss and survival of dental implants

“…A retrospective study to compare 3 different types of implant-supported fixed dental prostheses—3 non-splinted crowns, 3 splinted crowns, and 3-unit implant-supported bridges over 2 implants—reported that the peri-implantitis incidence rate of 3-unit implant-supported bridges was comparable to that of non-splinted crowns, and that it was lower than that of splinted crowns [ 32 ]. In contrast, Alhammadi et al [ 33 ] found that the marginal bone loss around 3-unit implant-supported fixed prostheses was significantly greater than that around single crown-supported implants 1 year after prosthetic loading. In the present study, implant-supported bridges had greater marginal bone loss than single or splinted crowns, which is in accord with the findings of Alhammadi et al [ 33 ].…”

“…In contrast, Alhammadi et al [ 33 ] found that the marginal bone loss around 3-unit implant-supported fixed prostheses was significantly greater than that around single crown-supported implants 1 year after prosthetic loading. In the present study, implant-supported bridges had greater marginal bone loss than single or splinted crowns, which is in accord with the findings of Alhammadi et al [ 33 ]. Although the prosthetic types were divided into 3 groups in this study, the situation for each prosthetic type varied more than could be captured by a tripartite classification.…”

What Does Bone Corticalization around Dental Implants Mean in Light of Ten Years of Follow-Up?

“…Relating this to the clinical results obtained, it seems that the numerical experiments did not take into account the role of technical fabrication difficulties (risk of residual stresses, problems with compensating for nonparallelism) and the role of oral hygiene, which is more difficult in splinted crown work. There are reports [ 46 ] describing bridgeworks as significantly more affected by marginal crestal bone loss compared to single-crown-supported implants in short-term studies. In this long-term study, however, single crowns were the best prosthetic solution.…”