Non-Cochrane · intervention · PM42460244
Immediate or Early vs. Delayed Loading Protocols for Two-Implant Mandibular Overdentures in Edentulous Population: A Comprehensive Systematic Review and Meta-Analysis of Randomized Controlled Trials.
Sharifi Morteza, Rezaeiyazdi Asal, Mohammadzadeh Mehdi, et al. · Health science reports · 2026 · PubMed · doi:10.1002/hsr2.72817
Findings
Population Fully edentulous mandible rehabilitated with two-implant mandibular overdentures
19 findings
| Immediate or early loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Overall | WMD -0.13 [-0.23, -0.03] Low Downgraded: risk of bias, inconsistency, publication bias 13 studies · 580 participants |
| Immediate or early loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Sensitivity: trim-and-fill | WMD -0.129 [-0.233, -0.026] GRADE not reported Studies not reported |
| Immediate or early loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Sensitivity: leave-one-out | Leave-one-out sensitivity analysis: WMD remained stable, ranging from approximately -0.10 to -0.18 mm when each study was omitted (Figure S1, image not available) GRADE not reported Studies not reported |
| Early loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Early / delayed loading subgroup | WMD -0.24 [-0.44, -0.05] GRADE not reported 8 studies |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Risk of bias: low | WMD -0.29 [-0.54, -0.04] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Risk of bias: unclear | WMD -0.28 [-0.57, -0.10] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Imaging modality: periapical | WMD -0.07 [-0.14, -0.01] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Attachment: ball | WMD -0.18 [-0.49, -0.03] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Immediate / delayed loading subgroup | WMD -0.03 [-0.09, 0.03] GRADE not reported 5 studies |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Surface: not reported | WMD -0.28 [-0.50, -0.05] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Risk of bias: high | WMD -0.17 [-0.38, -0.04] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Attachment: ball and equator | WMD -0.73 [-1.06, -0.40] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Imaging modality: not reported | WMD -0.22 [-0.41, -0.03] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Surface: fluoride-modified microrough titanium | WMD -0.44 [-0.84, -0.05] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Attachment: locator | WMD -0.31 [-0.52, -0.10] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Implant type: tissue level | WMD -0.10 [-0.27, -0.01] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Surface: SLActive/laser lock | WMD -0.12 [-1.06, -0.01] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Implant type: bone level | WMD -0.55 [-0.87, -0.23] GRADE not reported Studies not reported |
| Immediate loading | Delayed loading | Marginal bone loss (MBL) Two-implant mandibular overdentures · Attachment: bar-clip | WMD 0.38 [0.14, 0.62] GRADE not reported Studies not reported |
Included primary studies 25
Open in Studies| Study | Year | Also included by | Outcomes it informs here | Trial data |
|---|---|---|---|---|
| Alfadda 2019 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Aunmeungtong 2017 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Bielemann 2019 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Chatrattanarak 2022 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Elsyad 2012 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Elsyad 2014 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Ibraheem 2019 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Kutkut 2019 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Payne 2002 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Reis 2019 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Salman 2019 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Schincaglia 2016 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Schuster 2020 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Tawse-Smith 2002 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Ter Gunne 2016 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Tozum 2007 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Turkyilmaz 2004 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Turkyilmaz 2006 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Turkyilmaz 2006a matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Turkyilmaz 2006b matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Turkyilmaz 2006c matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Turkyilmaz 2007 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Turkyilmaz 2010 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Turkyilmaz 2012 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
| Zygogiannis 2017 matched by author and year (probable) | NR | this review only | not stated | not extracted yet |
Review question
| Element | Planned (methods) | Found (results) |
|---|---|---|
| Population | Individuals fully edentulous in the mandibular arch with two-implant overdentures | Fully edentulous mandible, two-implant overdentures (n=580 patients; 1186 implants) |
| Intervention | Immediate or early loading | Immediate loading; early loading (n=296 patients) |
| Comparison | Delayed loading | Delayed loading (n=284 patients) |
| Outcomes | Marginal bone loss (primary); implant survival and success, prosthetic complications, patient satisfaction | Marginal bone loss (13 studies pooled); survival, success, QoL, pain not pooled |
| Study designs | Randomized controlled trials | 22 RCTs |
| Timing | Not specified | Not specified |
AMSTAR 2 items
Two independent extractors rated each item. Their ratings are shown side by side because they have not been reconciled yet. The overall rating follows Shea et al. 2017: one critical flaw gives Low, more than one gives Critically Low.
| Item | Extractor A | Extractor B | Agree |
|---|---|---|---|
| 1Research question includes PICO components | Yes | Yes | yes |
| 2Protocol established before the reviewcritical | Partial Yes | Partial Yes | yes |
| 3Choice of study designs explained | Yes | Yes | yes |
| 4Comprehensive literature searchcritical | No | Partial Yes | no |
| 5Study selection in duplicate | Yes | Yes | yes |
| 6Data extraction in duplicate | Yes | Yes | yes |
| 7List of excluded studies with reasonscritical | No | No | yes |
| 8Included studies described in detail | Yes | Yes | yes |
| 9Risk of bias assessed satisfactorilycritical | RCT: Yes | NRSI: N/A · RCT: Yes | no |
| 10Funding of included studies reported | No | No | yes |
| 11Appropriate meta-analysis methodscritical | RCT: No | NRSI: N/A · RCT: No | no |
| 12Impact of risk of bias on the pooled results | Yes | Yes | yes |
| 13Risk of bias accounted for in interpretationcritical | Yes | Yes | yes |
| 14Heterogeneity explained | Yes | Yes | yes |
| 15Publication bias investigatedcritical | Yes | Yes | yes |
| 16Conflicts of interest reported | Yes | Yes | yes |
| Overall | Critically Low | Critically Low | yes |