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

Abstract

PURPOSE To compare the clinical outcomes of two types of implant restoration for posterior edentulous area, 3-unit bridge supported by 2 implants and 3 implant-supported splinted crowns. MATERIALS AND METHODS The data included 127 implant-supported fixed restorations in 85 patients: 37 restorations of 3-unit bridge supported by 2 implants (2-IB), 37 restorations of 3 implant-supported splinted crowns (3-IC), and 53 single restorations (S) as controls. Peri-implantitis and mechanical complications that occurred for 14 years were analyzed by multivariable Cox regression model. Kaplan-Meier curves and the multivariable Cox regression model were used to analyze the success and survival of implants. RESULTS Peri-implantitis occurred in 28.4% of 2-IB group, 37.8% of 3-IC group, and 28.3% of S control group with no significant difference. According to the implant position, middle implants (P2) of the 3-IC group had the highest risk of peri-implantitis. The 3-IC group showed a lower mechanical complication rate (7.2%) than the 2-IB (16.2%) and S control group (20.8%). The cumulative success rate was 52.8% in S (control) group, 62.2% in 2-IB group, and 60.4% in 3-IC group. The cumulative survival rate was 98.1% in S (control) group, 98.6% in 2-IB group, and 95.5% in 3-IC group. There was no significant difference in the success and survival rate according to the restoration type. CONCLUSION The restoration type was not associated with the success and survival of implants. The risk of mechanical complications was reduced in 3 implant-supported splinted crowns. However, the middle implants of the 3 implant-supported splinted crowns had a higher risk of peri-implantitis.

Radiographic evaluation of marginal bone levels around implants supporting splinted fixed bridges: A retrospective study on 412 implants

“…(2013) reported that the plaque index and buccal pocket depth were higher in fixed partial dentures supported by three implants than bridges supported by two dental implants. The same authors also reported data confirming that over‐countered protheses increase the risk of peri‐implantitis, particularly at the level of implants located between the first and last (Yi et al., 2022). Ravidà et al.…”

“…Initially, Yi et al. showed that external connection type implants had higher risk of peri‐implantitis (Yi et al., 2020), while in the latest publication, the same authors observed no statistically significant differences between the two types of connection (Yi et al., 2022). However, results showed that abutments fractured more frequently between components of the internal conical connection type, especially in prostheses that used gold cylinders (C‐Gold, S‐UCLA) (Yi et al., 2021).…”

“…It seems that the type of connection did not have a statistically significant influence on the primary outcome. Initially, Yi et al showed that external connection type implants had higher risk of peri-implantitis (Yi et al, 2020), while in the latest publication, the same authors observed no statistically significant differences between the two types of connection (Yi et al, 2022). However, results showed that abutments fractured more frequently between components of the internal conical connection type, especially in prostheses that used gold cylinders (C-Gold, S-UCLA) (Yi et al, 2021) Once transmitted to the implant these are discharged at the level of the surrounding peri-implant bone, generating stress that can compromise the osseointegration that has already taken place.…”

“…Similarly, central implants supporting fixed splinted crowns showed a four‐time higher risk of peri‐implant disease. In this prosthetic design, namely three‐unit splinted crowns, although the risk of mechanical complications is reduced, the middle implant of three‐unit splinted crown is more susceptible to peri‐implantitis (Yi et al., 2022). Apart from prosthetic factors, it is also well known that the maintenance of a good oral hygiene within the interproximal spaces is essential to preserve the health of marginal peri‐implant tissues (Monje et al., 2016).…”