Table 1.
Overview of the Included Studies.
| Study | Funding | n | Specimen Origin | Exclusion CRITERIA | WSLs Preparation (pH for hours) | Outcome Reported |
|---|---|---|---|---|---|---|
| Pancu et al. 2011 (Romania) [42] | NR | 10 | Human (bicusps or molars) | NR | pH: 4.4 for 120 h | Microhardness (Vicker hardness- special device for microhardness testing with a squared diamond head) |
| Meyer-Lueckel et al. 2011 (Germany) [59] | DFG: PA 1508/1-1. HML and SP and royalties from DMG, Hamburg | 20 | Human (molars and premolars) |
Active non-cavitated proximal WSL (ICDAS code 2) | Without demineralization | Penetration Depth (Confocal laser scanning microscopy (CLSM) |
| Paris et al. 2011 B (Germany) [62] | Institute for Immunology, UK-SH, Christian-Albrechts Universitat zu Kiel for providing the CLSM. The Charité—Universitatmedizin Berlin holds US and European patents | 19 | Human (molars and premolars) |
Active non-cavitated proximal lesions scored as ICDAS 2 | Without demineralization | Penetration Depth (confocal laser scanning microscope) |
| Paris et al. 2011 A (Germeny) [64] | DFG: PA 1508/1-2, as part partially by DMG. | 16 | Human (molars) |
Cavitated lesions | Without demineralization | Penetration Depth (Confocal laser scanning microscopy CLSM) |
| Taher et al. 2012 (Saudi Arabia) [47] | No | 10 | Human (premolars) |
Cracks, restorations, or developmental lesions | Without demineralization | Roughness; Microhardness (microscope with 200 magnification and application of applying a load of 300 g; profilometer) |
| Torres et al. 2012 (Brazil) [48] | NR | 15 | Bovine (incisors) |
Damaged or not intact enamel | pH: 5 for 16 h | Microhardness (microhardness tester fitted with a 50-g load) |
| Attin et al. 2012 (Switzerland) [32] | Dentaurum, 3M ESPE, and DMG | 12 | Bovine (incisors) |
NR | pH: NR for 504 h | Shear Bond Strength (universal testing machine) |
| Veli et al. 2014 (Turkey) [72] | No | 20 | Human (premolars) |
Caries, hypoplastic areas, restorations, and surface abnormalities | pH: 4.8 for 504 h | Shear Bond Strength (universal testing machine) |
| Ekizer et al. 2012 (Turkey) [70] | No | 20 | Human (premolars) |
Hypoplastic spots, cracks, or gross irregularities | pH: 4.3 for 6 h | Shear Bond Strength (universal testing machine) |
| Paris et al. 2013 (Germany) [43] |
DFG: PA1508/1-2. HML and SP and royalties from DMG, Hamburg. | 12 | Bovine (incisors) |
NR | pH: 4.95 for 1200 h | Microhardness (Vickers hardness with a force (F) of 0.981 N for 10 s) |
| Paris et al. 2013 (Germany) [61] |
DFG: PA 1508/1-1 | 15 | Human (molars and premolars) |
Cavitated caries | Without demineralization | Penetration Depth (confocal laser scanning) |
| Mohammed et al. 2014 (Iraq) [76] | NR | 56 | Human (premolars) |
NR | pH: 4.5 for 120 h | Roughness (profilometer) |
| Paris et al. 2014 (Germany) [63] | DFG: PA 1508/1-3 | 9 | Human (molars and premolars) |
ICDAS codes 0, 1, 2 | Without demineralization | Penetration Depth (dual fluorescence confocal microscopy) |
| Lausch et al. 2014 (Germany) [57] | The Charité Universitätsmedizin Berlin and DMG | 17 | Human (molars and premolars) |
Without active or cavitated WSL | Without demineralization | Penetration Depth (confocal laser scanning) |
| Gelani et al. 2014 (USA) [56] | No | 42 | Bovine (incisors) |
WSP, cracks, or any other defect | pH:5 for 24 h | Penetration Depth (Confocal Laser Scanning Microscopy and Transverse Microradiography) |
| Dilber et al. 2014 (Turkey) [69] | NR | 15 | Human (mandibular lateral teeth) |
Hypoplastic areas, cracks, or gross irregularities in enamel | ph:4.3 for 6 h | Shear Bond Strength (Universal testing machine) |
| Montasser et al. 2015 (Egypt) [41] | No | 10 | Human (NR) |
NR | pH: 4.4 for 504 h | Microhardness (Vickers diamond indenter load of 200 g) |
| Arslan et al. 2015 (Turkey) [31] | NR | 15 | Human (central incisors) |
NR | pH: 4.5 for 6 h | Roughness; Microhardness (profilometer; Vickers hardness tester with 2 N load) |
| Min et al. 2015 (South Korea) [60] | Basic Science Research Program through the National Research Foundation of Korea (2013R1A1A2062505) | 20 | Bovine (permanent anterior teeth) |
NR | pH:4.8 for 960 h | Penetration Depth (Optical coherence tomography Confocal laser scanning microscopy)) |
| Vianna et al. 2015 (Brazil) [73] | No | 15 | Bovine (incisors) |
NR | pH:5 for 56 h | Shear Bond Strength (universal testing machine) |
| Gurdogan et al. 2016 (Turkey) [38] | No | 20 | Bovine (incisors) |
NR | pH: 4 for 2 h | Microhardness (Vickers Hardness tester with 100 gr force) |
| Abdel-Hakim et al. 2016 (Egypt) [28] | NR | 6 | Human (molars) |
Caries, hypocalcifications, or restorations | pH: 4.4 for 480 h | Microhardness (Vickers michrohardness testing with 200 gm load) |
| El-zankalouny et al. 2016 (Egypt) [46] | No | 7 | Human (premolars) |
Cracks, caries, or restorations | pH: 4.4 for 96 h | Microhardness; Penetration Depth (Vickers tester with f 50 g; stereomicroscope) |
| Abdellatif et al. 2016 (Egypt) [29] | NR | 11 | Human (anterior teeth) |
NR | pH: 4.8 for 720 h | Microhardness (Vicker’s microhardness test with load of 200 g) |
| Baka et al. 2016 (Turkey) [52] | NR | 20 | Human (premolars) |
Hypoplastic areas, cracks, restorations, or gross irregularities | pH: 4.8 for 504 h | Roughness; Shear Bond Strengths (profilometer; a universal testing machine) |
| Neto et al. 2016 (Brazil) [30] | CAPES, Funcap, and CNPq (Brazilian agencies). Project PON 254/Ric |
10 | Human (molars) |
NR | pH: 4.9 for 16 h | Microhardness (Knoop microhardness) |
| Horuztepe et al. 2017 (Turkey) [39] | No | 45 | Bovine (incisors) |
Cracks or other surface defects | pH: 4.95 for 672 h | Microhardness (microindentation hardness tester with a 50-g load) |
| Mandava et al. 2017 (India) [40] | No | 20 | Human (maxillary central incisors) |
Presence of cracks and defects | pH: 4.4 for 96 h | Microhardness; Penetration Depth (Vicker’s microhardness tester with a 300 g load; confocal laser fluorescence microscope) |
| Aziznezhad et al. 2017 (Iran) [34] | Babol University grant | 10 | Human (premolars) |
Not intact and time of extraction more than 3 months | pH: 4.5 for 6 h | Microhardness (Vickers device with 500 g load) |
| Prajapati et al. 2017 (India) [44] | No | 10 | Human (premolars) |
Teeth with hypoplasia or incipient carious lesions/WSL | pH:4.4 for 504 h | Microhardness (Vickers microhardness tester with 100 g load) |
| Sava-Rosianu et al. 2017 (Romania) [65] | Project for young researchers—Programme II-C3-TC-2015 | 60 | Human (premolar) |
NR | NR | Penetration Depth (Confocal Laser Scanning Microscopy) |
| Attia et al. 2018 (Egypt) [77] | NR | 20 | Bovine (NR) |
Cracks or defects in the surface | pH:5 for 24 h | Microhardness (micro-indentation hardness tester (with a 50-g load) |
| Nabil et al. 2018 (Egypt) [27] | NR | 15 | Human (anterior teeth) |
Cracks and any developmental defects | pH: NR for 1 h | Roughness; Microhardness (profilometer; Vickers Tester with load of 200 g) |
| Enan et al. 2018 (Egypt) [37] | NR | 10 | Human (bicuspid) |
Cracks and defects | pH: 4.95 for 160 h | Roughness; Microhardness (profilometer; universal testing machine) |
| Khalid et al. 2018 (Indonesia) [54] | University of Indonesia | 10 | Human (premolars) |
Enamel surface that was attached orthodontic appliance; WSL, defects on the buccal side of enamel; restorations | Without demineralization | Roughness (profilometer) |
| Yazkan et al. 2018 (Turkey) [49] | Suleyman Demirel University Scientific Research Projects Foundation (2969-D-11) | 16 | Bovine (incisors) |
Caries, fracture, or other defects | pH: 5 for 240 h | Roughness; Microhardness (profilometer; Vickers indenter, with load of 200 g) |
| Askar et al. 2018 (Germany) [55] | Deutsche Forschungsgemeinschaft (DFG; PA 1508/1-3), and DMG | 15 | Human (NR) |
Active proximal lesions with ICDAS-2, 3 and 5 | Without demineralization | Penetration Depth (confocal microscopy) |
| Aswani et al. 2019 (India) [51] | No | 10 | Human (anterior teeth) |
NR | pH:4.4 for 144 h | Roughness (profilometer) |
| Enan et al. 2019 (Egypt) [53] | No | 30 | Human (premolars) |
NR | pH:4.95 for 160 h | Roughness (profilometer) |
| Arora et al. 2019 (India) [50] | No | 30 | Bovine (premolars) |
Caries | pH: 4.5 for 96 h | Roughness; Penetration Depth (optical profilometer) |
| Theodory et al. 2019 (USA) [66] | Student Government for Graduate and Professional Students at the University of Iowa | 15 | Human (molars) |
NR | pH: 4.3 for 2160 h | Penetration Depth (Confocal Laser Scanning Microscopy) |
| López et al. 2019 (Brazil) [59] | NR | 8 | Human (NR) |
Cavity lesions, white stains, cracks, or structural alterations and restorations | pH: 5 for 0.5 h | Penetration Depth (Confocal Laser Scanning Microscopy) |
| Gulec et al. 2019 (Turkey) [71] | NR | 20 | Human (premolars) |
Caries, attrition, fracture, restoration, congenital or surface anomalies, or surface | pH: 4.5 for 22 h | Shear Bond Strength (universal testing machine) |
| Borges et al. 2019 (Brazil) [68] | FAPESP(2010/16878-7, 2010/17757-9) | 30 | Bovine (incisors) |
NR | pH:5 for 16 h | Shear Bond Strength (Scanning electron microscopy (SEM)) |
| Ayad et al. 2020 (Egypt) [33] | NR | 7 | Bovine (anteriors) |
NR | pH: 4.4 for 96 h | Microhardness (Vickers indenter, with a static load of 200 g) |
| Behrouzi P et al. 2020 (Iran) [35] | No | 15 | Human (maxillary central incisors) |
Cracks, caries, or mineralization defects | pH: 4.5 for 96 h | Microhardness (Vickers hardness tester with 50 kg load) |
| El Meligy, 2020 (Saudi Arabia) [36] | No | 27 | Human (premolars) |
ICDAS 1 and 2 | pH: 4.5 for 399 h | Microhardness (transversal Vickers hardness with a force of 0.891 N) |
| Wang et al. 2020 (Brazil) [67] | FAPESP, 2012/13160-3, #2012/18579-2 and 2013/23310-5) CAPES—Brasil | 13 | Bovine (incisors) |
NR | pH: 4.7 for 168 h | Penetration Depth (confocal laser scanning microscopy) |
CAPES—Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; CLSM—Confocal Laser Scanning Microscope; CNPq-Conselho Nacional de Desenvolvimento Científico e Tecnológico; DFG—Deutsche Forschungsgemeinschaft; FAPESP—Fundação de Amparo à Pesquisa do Estado de São Paulo; FUNCAP—Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico; H—Hours; HML—Hendrik Meyer-Lueckel; ICDAS—International Caries Detection and Assessment System; NR—Not reported; WSL—white spots lesions; S.P—Sebastian Paris.