Non-Cochrane · intervention · PM42078835
The effect of manufacturing technique on marginal gap in inlay, onlay, veneer, and endocrown restorations: a systematic review and metaanalysis.
Alawawda Osayd, Binici Ensar, Akıncı Ilgınsu, et al. · European oral research · 2026 · PubMed · doi:10.26650/eor.20261751100
Findings
4 findings
| Population | ||||
|---|---|---|---|---|
| Indirect partial-coverage restorations (inlays, onlays, laminate veneers, occlusal veneers, endocrowns), in vitro | Milled (subtractive manufactured) restorations | 3D-printed (additive manufactured) restorations | Marginal gap (marginal fit) In vitro (laboratory) | SMD 0.20 [-0.63, 1.02] GRADE not reported 16 studies · 544 participants |
| Inlays and onlays, in vitro | Milled (subtractive manufactured) restorations | 3D-printed (additive manufactured) restorations | Marginal gap (marginal fit) In vitro (laboratory) · Inlay and onlay | SMD 0.87 [-0.26, 2.00] GRADE not reported 9 studies · 298 participants |
| Laminate veneers, in vitro | Milled (subtractive manufactured) restorations | 3D-printed (additive manufactured) restorations | Marginal gap (marginal fit) In vitro (laboratory) · Laminate veneers | SMD -0.24 [-1.60, 1.13] GRADE not reported 4 studies · 136 participants |
| Occlusal veneers, in vitro | Milled (subtractive manufactured) restorations | 3D-printed (additive manufactured) restorations | Marginal gap (marginal fit) In vitro (laboratory) · Occlusal veneer | SMD -1.86 [-18.24, 14.53] GRADE not reported 2 studies · 80 participants |
Included primary studies 16
Open in Studies| Study | Year | Also included by | Outcomes it informs here | Trial data |
|---|---|---|---|---|
| Ahlholm 2024 Accuracy of Dental Restorations Fabricated Using Milling vs 3D-Printed Molds: A Pilot Study. PMID:38498860 | 2024 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Cakmak 2024 Fabrication Trueness, Intaglio Surface Adaptation, and Marginal Integrity of Resin-Based Onlay Restorations Fabricated by Additive and… PMID:37988421 | 2024 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Canto-Naves 2023 In Vitro Comparison of Internal and Marginal Adaptation between Printed and Milled Onlays. PMID:37959559 | 2023 | this review only | Marginal gap (marginal fit) | not extracted yet |
| D'haese 2024 Fit and Fracture Load of Milled and 3D-Printed Composite Onlays: An In Vitro Study. PMID:40131126 | 2025 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Daghrery 2024 Marginal Discrepancy and Internal Fit of 3D-Printed Versus Milled Laminate Veneers: An In Vitro Study. PMID:39590542 | 2024 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Daghrery 2025 Dimensional accuracy of additive and subtractive manufactured ceramic-reinforced hybrid composite inlays: a CBCT-based in vitro study. PMID:39972095 | 2025 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Demirel 2025 Effect of manufacturing trinomial and restoration thickness on the fabrication trueness, fit, and margin quality of additively… PMID:39900134 | 2025 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Homsy 2018 Marginal and internal fit of pressed lithium disilicate inlays fabricated with milling, 3D printing, and conventional technologies. PMID:28969918 | 2018 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Ioannidis 2021 An in vitro comparison of the marginal and internal adaptation of ultrathin occlusal veneers made of 3D-printed zirconia, milled zirconia,… PMID:33741143 | 2022 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Kang 2018 Evaluation of marginal discrepancy of pressable ceramic veneer fabricated using CAD/CAM system: Additive and subtractive manufacturing. PMID:30370025 | 2018 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Keskin 2025 Effect of conventional and digital fabrication techniques on marginal and internal fit of lithium disilicate endocrowns. PMID:40119390 | 2025 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Lim 2023 Evaluation of Fitness and Accuracy of Milled and Three-Dimensionally Printed Inlays. PMID:36599450 | 2023 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Paque 2024 Load-bearing capacity, internal accuracy and time-efficiency of heat-pressed, milled and 3D-printed lithium disilicate ultra-thin occlusal… PMID:39079765 | 2024 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Pasha 2023 Evaluation of Internal Adaptation and Marginal Fit of Onlays Fabricated Using Computer-Aided Design (CAD)-Computer-Aided Manufacturing… PMID:37425511 | 2023 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Revilla-Leon 2018 Marginal and Internal Gap of Handmade, Milled and 3D Printed Additive Manufactured Patterns for Pressed Lithium Disilicate Onlay… PMID:29461746 | 2018 | this review only | Marginal gap (marginal fit) | not extracted yet |
| Rues 2023 Fit of anterior restorations made of 3D-printed and milled zirconia: An in-vitro study. PMID:36640843 | 2023 | this review only | Marginal gap (marginal fit) | not extracted yet |
Review question
| Element | Planned (methods) | Found (results) |
|---|---|---|
| Population | Partial-coverage indirect dental restorations (inlays, onlays, veneers, occlusal veneers, endocrowns) | Inlays/onlays (n=9), laminate veneers (n=4), occlusal veneers (n=2), endocrowns (n=1) |
| Intervention | 3D printing (additive manufacturing) | 3D-printed restorations (n=287 samples) |
| Comparison | Milling (subtractive manufacturing) | Milled restorations (n=257 samples) |
| Outcomes | Marginal gap or marginal fit | Marginal gap, SMD (16 studies) |
| Study designs | In vitro studies, RCTs, prospective/retrospective comparative studies | In vitro studies (16) |
| 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 | No | No | yes |
| 3Choice of study designs explained | No | No | 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 | Partial Yes | Partial Yes | yes |
| 9Risk of bias assessed satisfactorilycritical | NRSI: Partial Yes · RCT: N/A | RCT: N/A · NRSI: Partial Yes | no |
| 10Funding of included studies reported | No | No | yes |
| 11Appropriate meta-analysis methodscritical | NRSI: Partial Yes · RCT: N/A | NRSI: Yes · RCT: N/A | no |
| 12Impact of risk of bias on the pooled results | No | No | yes |
| 13Risk of bias accounted for in interpretationcritical | No | No | yes |
| 14Heterogeneity explained | Yes | Yes | yes |
| 15Publication bias investigatedcritical | No | No | yes |
| 16Conflicts of interest reported | Yes | Yes | yes |
| Overall | Critically Low | Critically Low | yes |