Non-Cochrane · intervention · PM40616206
Is Additive Manufacturing of Dental Zirconia Comparable to Subtractive Methods When Considering Printing Orientation and Layer Thickness? A Systematic Review and Meta-Analysis.
Ruggiero Mirelle M, Souza Letícia V S, Magno Marcela B, et al. · Journal of esthetic and restorative dentistry : official publication of the American Academy of Esthetic Dentistry ... [et al.] · 2026 · PubMed · doi:10.1111/jerd.13514
Findings
19 findings
| Population | ||||
|---|---|---|---|---|
| Monolithic dental zirconia (3Y-TZP) specimens | AM (SLA or DLP) zirconia, any printing direction and layer thickness | Subtractive manufacturing (SM; CIP/presintered, milled) zirconia | Surface roughness Not applicable (laboratory specimens) · Laboratory (in vitro) · Analysis 1: printing direction coded 0 degree, 90 degree and not reported (Abualsaud 90 degree) | MD -0.02 [-0.13, 0.08] GRADE not reported 5 studies · 68 participants |
| Monolithic dental zirconia (3Y-TZP) specimens | AM (SLA or DLP) zirconia, any printing direction and layer thickness | Subtractive manufacturing (SM; CIP/presintered, milled) zirconia | Density Not applicable (laboratory specimens) · Laboratory (in vitro) · Analysis 1: printing direction coded 0 degree, 90 degree and not reported (Abualsaud 90 degree) | MD -0.02 [-0.02, -0.01] GRADE not reported 7 studies · 100 participants |
| Monolithic dental zirconia (3Y-TZP) specimens | AM (SLA or DLP) zirconia, any printing direction and layer thickness | Subtractive manufacturing (SM; CIP/presintered, milled) zirconia | Density Not applicable (laboratory specimens) · Laboratory (in vitro) · Analysis 2: printing direction coded 0 degree and not reported | MD -0.02 [-0.02, -0.01] GRADE not reported 7 studies · 100 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing (SLA or DLP) zirconia, all printing directions and layer thicknesses | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · Overall | MD -232.25 [-255.64, -208.86] GRADE not reported 12 studies · 494 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing (SLA or DLP) zirconia, all printing directions and layer thicknesses | Subtractive manufacturing (CIP/presintering/milling) zirconia | Surface roughness Laboratory (in vitro) · Overall analysis 2 (Abualsaud et al. entered at 0 degrees) | MD -0.03 [-0.13, 0.07] GRADE not reported 5 studies · 68 participants |
| Monolithic dental zirconia (3Y-TZP) specimens | AM (SLA or DLP) zirconia, any printing direction and layer thickness | Subtractive manufacturing (SM; CIP/presintered, milled) zirconia | Uniaxial flexural strength (UFS) Not applicable (laboratory specimens) · Laboratory (in vitro) · Uniaxial flexural strength assessment | MD -84.54 [-347.79, 178.72] GRADE not reported 8 studies · 250 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia printed at 90 degrees | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · Printing direction 90 degrees | MD -266.54 [-470.64, -62.43] GRADE not reported 7 studies · 239 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia printed at 0 degrees | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · Printing direction 0 degrees | MD -120.5 [-243.3, 2.3] GRADE not reported 10 studies · 378 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia by DLP | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · DLP technology | MD -133.3 [-240.87, -25.73] GRADE not reported 11 studies · 465 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia by SLA | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · SLA technology | MD -204.72 [-437.45, 28.0] GRADE not reported 8 studies · 202 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia assessed by biaxial flexural strength (BFS) | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · BFS subgroup | MD -156.83 [-243.79, -69.87] GRADE not reported 6 studies · 244 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia printed at 0 degrees, UFS | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · 0 degrees and UFS | MD -85.02 [-392.83, 222.8] GRADE not reported 5 studies · 162 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia printed at 0 degrees, BFS | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · 0 degrees and BFS | MD -146.92 [-269.2, -24.64] GRADE not reported 6 studies · 216 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia printed at 90 degrees, UFS | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · 90 degrees and UFS | MD -207.99 [-366.04, -49.93] GRADE not reported 4 studies · 112 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia printed at 90 degrees, BFS | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · 90 degrees and BFS | MD -339.07 [-826.7, 148.56] GRADE not reported 3 studies · 127 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia with 25 um layer thickness | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · 25 um layer thickness | MD -111.86 [-206.88, -16.84] GRADE not reported 4 studies · 258 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia with 50 um layer thickness | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · 50 um layer thickness | MD -158.65 [-235.06, -82.24] GRADE not reported 2 studies · 70 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia with 25 um layer thickness printed at 0 degrees | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · 25 um layer thickness and 0 degrees | MD -215.46 [-376.05, -54.87] GRADE not reported 4 studies · 192 participants |
| Monolithic dental zirconia specimens (3Y-TZP) | Additive manufacturing zirconia with 25 um layer thickness printed at 90 degrees | Subtractive manufacturing (CIP/presintering/milling) zirconia | Flexural strength Laboratory (in vitro) · 25 um layer thickness and 90 degrees | MD -260.49 [-492.36, -28.62] GRADE not reported 6 studies · 209 participants |
Included primary studies 31
Open in Studies| Study | Year | Also included by | Outcomes it informs here | Trial data |
|---|---|---|---|---|
| Abualsaud 2022 Physiomechanical and Surface Characteristics of 3D-Printed Zirconia: An In Vitro Study DOI:10.3390/ma15196988 | 2022 | this review only | not stated | not extracted yet |
| Alshamrani 2024 Flexural properties and finite element analysis of novel <scp>3D</scp>‐printed ceramic materials via <scp>3D</scp>‐<scp>LCM</scp> technology DOI:10.1111/adj.13048 | 2024 | this review only | not stated | not extracted yet |
| Bergler 2022 Ceramic Printing— Comparative Study of the Flexural Strength of 3D-Printed and Milled Zirconia DOI:10.11607/ijp.6749 | 2022 | this review only | not stated | not extracted yet |
| Cameron 2024 Assessment of the trueness of additively manufactured mol3% zirconia crowns at different printing orientations with an industrial and… DOI:10.1016/j.jdent.2024.104942 | 2024 | this review only | not stated | not extracted yet |
| Cho 2024 Trueness, physical properties, and surface characteristics of additive-manufactured zirconia crown DOI:10.1016/j.jmbbm.2024.106536 | 2024 | this review only | not stated | not extracted yet |
| Frąckiewicz 2024 Comparison of Dental Zirconium Oxide Ceramics Produced Using Additive and Removal Technology for Prosthodontics and Restorative… DOI:10.3390/ma17010168 | 2023 | this review only | not stated | not extracted yet |
| Giugliano 2023 In vitro comparison of physical characteristics of milled versus printed zirconia discs DOI:10.1111/jopr.13778 | 2023 | this review only | not stated | not extracted yet |
| Hetzler 2025 Biaxial Flexural Strength and Vickers Hardness of 3D-Printed and Milled 5Y Partially Stabilized Zirconia DOI:10.3390/jfb16010036 | 2025 | this review only | not stated | not extracted yet |
| Kessler 2024 Influence of additive and subtractive zirconia and lithium disilicate manufacturing on tensile bond strength and surface topography DOI:10.1016/j.prosdent.2024.04.002 | 2024 | this review only | not stated | not extracted yet |
| Kim 2022 Microstructure, Flexural Strength, and Fracture Toughness Comparison between CAD/CAM Milled and 3D-Printed Zirconia Ceramics DOI:10.3390/app12189088 | 2022 | this review only | not stated | not extracted yet |
| Kim 2023 The effect of surface treatment and low-temperature degradation on flexural strength of additive manufactured zirconia DOI:10.1016/j.jmbbm.2023.106167 | 2023 | this review only | not stated | not extracted yet |
| Kyung 2024 Comparative analysis of flexural strength of 3D printed and milled 4Y-TZP and 3Y-TZP zirconia DOI:10.1016/j.prosdent.2023.12.020 | 2024 | this review only | not stated | not extracted yet |
| Lou 2021 DOI:10.3760/cma.j.cn112144-20210330-00151 | NR | this review only | not stated | not extracted yet |
| Lu 2020 Flexural strength and Weibull analysis of Y-TZP fabricated by stereolithographic additive manufacturing and subtractive manufacturing DOI:10.1016/j.jeurceramsoc.2019.10.058 | 2020 | this review only | not stated | not extracted yet |
| Marsico 2020 Vat polymerization-printed partially stabilized zirconia: Mechanical properties, reliability and structural defects DOI:10.1016/j.addma.2020.101450 | 2020 | this review only | not stated | not extracted yet |
| Mei 2021 An investigation of the microstructure and mechanical properties of dental zirconia manufactured by digital light processing 3D printing. PMID:34636207 | 2021 | this review only | not stated | not extracted yet |
| Miura 2022 Comparative Evaluation of the Reproductive Trueness of Zirconia Crowns Fabricated Using Additive Manufacturing and Conventional Milling DOI:10.11607/ijp.7092 | 2022 | this review only | not stated | not extracted yet |
| Nakai 2021 Additively Manufactured Zirconia for Dental Applications DOI:10.3390/ma14133694 | 2021 | this review only | not stated | not extracted yet |
| Oh 2024 Mechanical properties and crown accuracy of additively manufactured zirconia restorations DOI:10.1016/j.dental.2024.07.016 | 2024 | this review only | not stated | not extracted yet |
| Revilla‐León 2021 Flexural strength and Weibull characteristics of stereolithography additive manufactured versus milled zirconia DOI:10.1016/j.prosdent.2020.01.019 | 2021 | this review only | not stated | not extracted yet |
| Revilla‐León 2022 Chemical Composition and Flexural Strength Discrepancies Between Milled and Lithography‐Based Additively Manufactured Zirconia DOI:10.1111/jopr.13482 | 2022 | this review only | not stated | not extracted yet |
| Rues 2024 Effect of firing time and wall thickness on the biaxial flexural strength of 3D-printed zirconia DOI:10.1016/j.dental.2023.12.018 | 2024 | this review only | not stated | not extracted yet |
| Tan 2022 Effect of high-speed sintering on the microstructure, mechanical properties and ageing resistance of stereolithographic… DOI:10.1016/j.ceramint.2021.12.181 | 2022 | this review only | not stated | not extracted yet |
| Tan 2022 Physical and biological implications of accelerated aging on stereolithographic additive-manufactured zirconia for dental implant abutment DOI:10.2186/jpr.jpr_d_21_00240 | 2021 | this review only | not stated | not extracted yet |
| Xiang 2021 Dental zirconia fabricated by stereolithography: Accuracy, translucency and mechanical properties in different build orientations DOI:10.1016/j.ceramint.2021.07.044 | 2021 | this review only | not stated | not extracted yet |
| Yoo 2023 Mechanical properties of additively manufactured zirconia with alumina air abrasion surface treatment DOI:10.1038/s41598-023-36181-6 | 2023 | this review only | not stated | not extracted yet |
| Zandinejad 2022 The Flexural Strength and Flexural Modulus of Stereolithography Additively Manufactured Zirconia with Different Porosities DOI:10.1111/jopr.13430 | 2021 | this review only | not stated | not extracted yet |
| Zandinejad 2022 Surface Roughness and Bond Strength of Resin Composite to Additively Manufactured Zirconia with Different Porosities DOI:10.1111/jopr.13434 | 2022 | this review only | not stated | not extracted yet |
| Zenthöfer 2022 Strength and reliability of zirconia fabricated by additive manufacturing technology DOI:10.1016/j.dental.2022.07.004 | 2022 | this review only | not stated | not extracted yet |
| Zhai 2024 Zirconia specimens printed by vat photopolymerization: Mechanical properties, fatigue properties, and fractography analysis DOI:10.1111/jopr.13942 | 2024 | this review only | not stated | not extracted yet |
| Zhai and Sun 2023 Research on the low-temperature degradation of dental zirconia ceramics fabricated by stereolithography DOI:10.1016/j.prosdent.2021.11.012 | 2023 | this review only | not stated | not extracted yet |
Review question
| Element | Planned (methods) | Found (results) |
|---|---|---|
| Population | Monolithic dental zirconia (crowns, partial restorations, disk/block specimens) | Dental zirconia specimens, mostly 3Y-TZP (25 of 31 studies); 21 studies (3Y-TZP, flat specimens) in meta-analysis |
| Intervention | Additive manufacturing by SLA or DLP | AM zirconia: DLP (18 studies), SLA (9), both (4); printing direction 0, 45, 90 degree; layer thickness 10, 25, 50 um |
| Comparison | Subtractive manufacturing (CIP/presintered, milled) | Milled (subtractive) zirconia, mainly 3Y-TZP |
| Outcomes | Flexural strength (primary); translucency, density, surface roughness | Flexural strength (22 studies; 12 pooled, 14 comparisons), density (7 studies pooled), surface roughness (5 studies pooled), translucency (2 studies, not pooled) |
| Study designs | In vitro studies | 31 in vitro studies (2020 to 2025); 21 in quantitative analysis |
| Timing | Not specified | Not applicable (in vitro) |
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 | No | No | yes |
| 4Comprehensive literature searchcritical | Partial Yes | Partial Yes | yes |
| 5Study selection in duplicate | Yes | Yes | yes |
| 6Data extraction in duplicate | Yes | Yes | yes |
| 7List of excluded studies with reasonscritical | Yes | Yes | yes |
| 8Included studies described in detail | Yes | Yes | yes |
| 9Risk of bias assessed satisfactorilycritical | RCT: N/A · NRSI: Partial Yes | NRSI: Partial Yes · RCT: N/A | no |
| 10Funding of included studies reported | No | No | yes |
| 11Appropriate meta-analysis methodscritical | RCT: N/A · NRSI: No | NRSI: Partial Yes · RCT: N/A | no |
| 12Impact of risk of bias on the pooled results | No | No | yes |
| 13Risk of bias accounted for in interpretationcritical | Yes | Yes | yes |
| 14Heterogeneity explained | Yes | Yes | yes |
| 15Publication bias investigatedcritical | No | No | yes |
| 16Conflicts of interest reported | Yes | Yes | yes |
| Overall | Critically Low | Low | no |