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Title Immediate Loading of Mandibular Overdentures Is Not Associated with Increased Implant Failure when Compared to Delayed Loading Protocols
Clinical Question For patients treated with mandibular overdentures, does immediate loading compared to delayed loading result in increased implant failure?
Clinical Bottom Line For patients undergoing mandibular overdenture treatment, there are no significant differences in implant failure rates between immediate and delayed loading protocols. These analyses encompass a range of abutment designs. Key considerations in selecting loading protocols should be the implant torque at insertion (following manufacturer protocols) and potential confounding factors (diabetes status, smoking, etc.), particularly during the critical healing period when the risk of failure is most pronounced.
Best Evidence (you may view more info by clicking on the PubMed ID link)
PubMed ID Author / Year Patient Group Study type
(level of evidence)
#1) 32684353Borges/202123 RCT/NRCTs (841 participants with 1874 implants placed)Meta-Analysis
Key resultsImmediately loaded (IL) implants had similar rates of bleeding on probing (BOP, with low certainty of evidence) and marginal bone loss (MBL, with moderate certainty of evidence) compared to conventional loaded (CL) implants at 3 to 36 months. CL implants had lower plaque index (PI) at 12 months (P=0.033) and shallower probing depths (PD) at 36 months (P=0.013) than IL implants. Most notably, implant stability quotient (ISQ) was significantly higher for CL implants at 3 months (P<0.001), though over longer time points, no differences were noted. Success rates and implant survival rates were consistently comparable between loading protocols, with a high certainty of evidence.
#2) 33546861Aldhohrah/202216 RCT (n=599 participants receiving 1198 dental implants)Meta-Analysis
Key resultsLOCATOR+delayed loading, resilient telescopic+delayed loading, and magnet+immediate loading achieved a pooled implant survival rate of 100%, while other attachments and loading protocols demonstrated survival rates ranging from 91.2% to 99.1%. However, appropriate network meta-analysis for implant survival could not be performed because most of the studies reported 0% implant failure in some or all groups. There were no differences between IL and CL protocols in MBL, PD or ISQ when pooled. This study focused on suggestive measurements of implant survival outcomes due to limited follow-up duration, indicating the need for larger sample sizes and longer follow-up periods.
#3) 33139056Cao/20217 RCTs (170 participants receiving 340 implants)Meta-Analysis
Key resultsThere were no statistically significant differences between IL and CL implants in failure rate (I2=0%; n=7; RD=0.03; 95% CI=-0.01 to 0.08) or MBL (I2=88%; n=6; MD=-0.04; 95% CI=-0.16 to 0.24). However, sensitivity analysis, after removing one study, indicated a higher failure rate with IL implants (I2=0%; n=6; RD=0.05; 95% CI=0.01 to 0.10) – 4.56% vs 1.21% for CL implants, mostly occurring during the initial healing period.
Evidence Search Search: (immediate loading) AND (mandibular overdenture) AND ((implant survival) OR (implant failure)) Filters: Meta-Analysis, Systematic Review Sort by: Publication Date
Comments on
The Evidence
All 3 studies followed Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines and searched multiple reputable databases and printed journals for eligible RCTs only (though Borges included NRCTs as well). Quality of RCTs were assessed by the Cochrane Collaboration risk of bias tool, and NRCTs by ROBINS-I tool. Factors such as implant failure/survival, MBL, PD, BOP, ISQ, PTV, and patient satisfaction were compared, however not all included studies within each analysis reported on all of these outcomes. There was moderate to high risk of bias for most of the assessed parameters, however, due to the dichotomous nature of implant survival/failure (in the bone vs. out of the bone) the results were still deemed valid with moderate/high certainty of evidence. Additionally, some of the measured parameters in all studies had considerable heterogeneity (indicating differences that could be due to chance), but only Cao and Aldhohrah addressed how these analyses were modified. Limitations in study sizes also may have affected the outcomes between analyses. All meta-analyses considered various attachment types for mandibular overdentures, however Cao considered only 2 implant overdentures. Borges pooled immediate and early loading into one category which may have diluted the sample depending on when the cutoff for “early loading” occurred. It is difficult to draw general conclusions about implant success in various loading protocols when the included studies do not have consistent measured parameters. Cao did find statistical significance in implant survival after exclusion of one of the studies; however, justification for exclusion was not provided and therefore the finding should be interpreted guardedly. Increasing length of follow-up intervals, clearly defining timepoints for immediate and conventional loading, and clearly defining implant “success”, “survival”, and “failure” parameters can all improve standardization of future RCTs. The conducted analyses indicate that there is no difference in implant “survival” between immediate and delayed/conventional loading; however, implant “success” may be different based on which parameters are evaluated.
Applicability For patients who are edentulous on the mandible, the current accepted standard of care is an implant retained mandibular overdenture. However, immediate loading of the implants has been controversial due to potential negative effects on osseointegration of implants leading to implant failure. These analyses show that immediate loading of implants does not have any higher risk of implant “failure” compared to delayed loading. This is important since immediate loading of implants can help improve patient satisfaction.
Specialty/Discipline (General Dentistry) (Oral Surgery) (Periodontics) (Prosthodontics)
Keywords Overdentures, immediate loading, delayed loading, implant failure
ID# 3537
Date of submission: 10/17/2023spacer
E-mail girnary@uthscsa.edu
Author Mustafa Girnary, DDS
Co-author(s) Jaehyun Kim, DDS
Co-author(s) e-mail kimj24@uthscsa.edu
Faculty mentor/Co-author Kyumin Whang, Ph.D.
Faculty mentor/Co-author e-mail whang@uthscsa.edu
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