{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,23]],"date-time":"2026-06-23T20:19:51Z","timestamp":1782245991626,"version":"3.54.5"},"reference-count":43,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2023,7,7]],"date-time":"2023-07-07T00:00:00Z","timestamp":1688688000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004488","name":"Croatian Science Foundation","doi-asserted-by":"publisher","award":["IP-2019-04-6183"],"award-info":[{"award-number":["IP-2019-04-6183"]}],"id":[{"id":"10.13039\/501100004488","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>This study analysed flexural properties, microhardness, and the degree of conversion (DC) of five bulk-fill composites under clinically relevant conditions (4 mm thick specimens) in comparison to 2 mm specimens according to ISO 4049. Additionally, the effect of rapid polymerisation on 4 mm specimens was evaluated after accelerated aging. DC was measured using Fourier transform infrared spectrometry at 2 and 4 mm thick layers, while flexural properties and Vickers microhardness were tested using 16 \u00d7 2 \u00d7 2 mm or 16 \u00d7 2 \u00d7 4 mm specimens. Three polymerisation protocols were used: (I) \u201cISO\u201d: 2 mm thickness, 1000 mW\/cm2, double-sided; (II) \u201c10 s\u201d: 4 mm thickness, 1000 mW\/cm2, one-sided; and (III) \u201c3 s\u201d: 4 mm thickness, 2600 mW\/cm2, one-sided. Mechanical properties were tested after 1 day, after 10,000 thermocycles, and after 10,000 thermocycles followed by a 7-day immersion in absolute ethanol. The \u201cISO\u201d protocol produced a higher DC and microhardness of all materials. Elastic modulus was significantly higher for the \u201cISO\u201d protocol compared to the 4 mm specimens. The differences in flexural strength for all polymerisation protocols were equalised after thermocycling and immersion in absolute ethanol. All tested materials met the ISO 4049 flexural strength requirement (80 MPa) for all polymerisation methods and all aging conditions. Rapid polymerisation achieved nearly optimal properties (ISO), except for elastic modulus, which was significantly reduced in 4 mm samples.<\/jats:p>","DOI":"10.3390\/ma16134868","type":"journal-article","created":{"date-parts":[[2023,7,7]],"date-time":"2023-07-07T02:37:29Z","timestamp":1688697449000},"page":"4868","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Proposition of New Testing Procedure for the Mechanical Properties of Bulk-Fill Materials"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4532-7368","authenticated-orcid":false,"given":"Matea","family":"Macan","sequence":"first","affiliation":[{"name":"Department of Endodontics and Restorative Dental Medicine, School of Dental Medicine, University of Zagreb, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ana","family":"Maro\u0161evi\u0107","sequence":"additional","affiliation":[{"name":"Department of Endodontics and Restorative Dental Medicine, School of Dental Medicine, University of Zagreb, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2545-4474","authenticated-orcid":false,"given":"Bruno","family":"\u0160piljak","sequence":"additional","affiliation":[{"name":"Department of Endodontics and Restorative Dental Medicine, School of Dental Medicine, University of Zagreb, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2848-6041","authenticated-orcid":false,"given":"Luka","family":"\u0160imunovi\u0107","sequence":"additional","affiliation":[{"name":"Department of Orthodontics, School of Dental Medicine, University of Zagreb, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2846-1840","authenticated-orcid":false,"given":"Matej","family":"Par","sequence":"additional","affiliation":[{"name":"Department of Endodontics and Restorative Dental Medicine, School of Dental Medicine, University of Zagreb, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3104-5749","authenticated-orcid":false,"given":"Danijela","family":"Marovic","sequence":"additional","affiliation":[{"name":"Department of Endodontics and Restorative Dental Medicine, School of Dental Medicine, University of Zagreb, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2929-0905","authenticated-orcid":false,"given":"Danijela","family":"Juric-Kacunic","sequence":"additional","affiliation":[{"name":"Private Dental Clinic, 76571 Gaggenau, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zrinka","family":"Tarle","sequence":"additional","affiliation":[{"name":"Department of Endodontics and Restorative Dental Medicine, School of Dental Medicine, University of Zagreb, 10000 Zagreb, Croatia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,7,7]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Haugen, H.J., Marovic, D., Par, M., Thieu, M.K.L., Reseland, J.E., and Johnsen, G.F. (2020). Bulk Fill Composites Have Similar Performance to Conventional Dental Composites. Int. J. Mol. Sci., 21.","DOI":"10.3390\/ijms21145136"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e138","DOI":"10.1016\/j.dental.2018.03.023","article-title":"Clinical evaluation of the bulk fill composite QuiXfil in molar class I and II cavities: 10-year results of a RCT","volume":"34","author":"Heck","year":"2018","journal-title":"Dent. Mater."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/j.jdent.2016.05.008","article-title":"Posterior bulk-filled resin composite restorations: A 5-year randomized controlled clinical study","volume":"51","author":"Pallesen","year":"2016","journal-title":"J. Dent."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Marovic, D., Par, M., Crnadak, A., Sekelja, A., Negovetic Mandic, V., Gamulin, O., Rakic, M., and Tarle, Z. (2021). Rapid 3 s Curing: What Happens in Deep Layers of New Bulk-Fill Composites?. Materials, 14.","DOI":"10.3390\/ma14030515"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"695","DOI":"10.1016\/j.jdent.2013.05.008","article-title":"Influence of various irradiation processes on the mechanical properties and polymerisation kinetics of bulk-fill resin based composites","volume":"41","author":"Ilie","year":"2013","journal-title":"J. Dent."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1991","DOI":"10.1007\/s00784-013-1177-y","article-title":"Light transmittance and micro-mechanical properties of bulk fill vs. conventional resin based composites","volume":"18","author":"Bucuta","year":"2014","journal-title":"Clin. Oral Investig."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"747","DOI":"10.1007\/s00784-018-2482-2","article-title":"Sufficiency of curing in high-viscosity bulk-fill resin composites with enhanced opacity","volume":"23","author":"Ilie","year":"2019","journal-title":"Clin. Oral Investig."},{"key":"ref_8","unstructured":"Todd, J. (2019). Scientific Documentation 3s PowerCure, Ivoclar Vivadent."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"7327","DOI":"10.1021\/ma501550b","article-title":"\u03b2-Allyl Sulfones as Addition\u2013Fragmentation Chain Transfer Reagents: A Tool for Adjusting Thermal and Mechanical Properties of Dimethacrylate Networks","volume":"47","author":"Gorsche","year":"2014","journal-title":"Macromolecules"},{"key":"ref_10","unstructured":"(2023, June 16). 3M Filtek One Bulk Fill Restaurative. Shrinkage, Stress and Bulk Fill Restoratives. Available online: https:\/\/multimedia.3m.com\/mws\/media\/1317665O\/1317663m-filtek-one-bulk-fill-restorative-shrink-stressand-bulk-fill-restoratives.pdf."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"901","DOI":"10.1016\/j.dental.2007.11.004","article-title":"Benzoyl germanium derivatives as novel visible light photoinitiators for dental materials","volume":"24","author":"Moszner","year":"2008","journal-title":"Dent. Mater."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Ilie, N. (2022). Resin-Based Bulk-Fill Composites: Tried and Tested, New Trends, and Evaluation Compared to Human Dentin. Materials, 15.","DOI":"10.3390\/ma15228095"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Marovic, D., Par, M., Macan, M., Klaric, N., Plazonic, I., and Tarle, Z. (2022). Aging-Dependent Changes in Mechanical Properties of the New Generation of Bulk-Fill Composites. Materials, 15.","DOI":"10.3390\/ma15030902"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"295","DOI":"10.1016\/j.jmbbm.2013.09.013","article-title":"Thermal cycling for restorative materials: Does a standardized protocol exist in laboratory testing? A literature review","volume":"29","author":"Morresi","year":"2014","journal-title":"J. Mech. Behav. Biomed. Mater."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"427","DOI":"10.1007\/s00784-009-0258-4","article-title":"Investigations on mechanical behaviour of dental composites","volume":"13","author":"Ilie","year":"2009","journal-title":"Clin. Oral Investig."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1016\/j.dental.2005.05.005","article-title":"Hygroscopic and hydrolytic effects in dental polymer networks","volume":"22","author":"Ferracane","year":"2006","journal-title":"Dent. Mater."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"1142","DOI":"10.1016\/j.dental.2006.06.049","article-title":"Aging studies of light cured dimethacrylate-based dental resins and a resin composite in water or ethanol\/water","volume":"23","author":"Sideridou","year":"2007","journal-title":"Dent. Mater."},{"key":"ref_18","unstructured":"(2000). Dentistry\u2014Polymer-Based Filling, Restorative and Luting Materials (Standard No. ISO 4049:2009)."},{"key":"ref_19","first-page":"547","article-title":"Flexure strength of methacrylate- and ormocer-based bulk fill resin composites: Effect of material thickness and distance to photo-polymerization device","volume":"35","author":"Botros","year":"2020","journal-title":"J. Adhes. Sci. Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"175","DOI":"10.3758\/BF03193146","article-title":"G*Power 3: A flexible statistical power analysis program for the social, behavioral, and biomedical sciences","volume":"39","author":"Faul","year":"2007","journal-title":"Behav. Res. Methods"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Barszczewska-Rybarek, I.M. (2019). A Guide through the Dental Dimethacrylate Polymer Network Structural Characterization and Interpretation of Physico-Mechanical Properties. Materials, 12.","DOI":"10.3390\/ma12244057"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"549","DOI":"10.1016\/j.jdent.2011.05.007","article-title":"High irradiance curing and anomalies of exposure reciprocity law in resin-based materials","volume":"39","author":"Hadis","year":"2011","journal-title":"J. Dent."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"583","DOI":"10.1016\/j.dental.2015.02.010","article-title":"Examining exposure reciprocity in a resin based composite using high irradiance levels and real-time degree of conversion values","volume":"31","author":"Selig","year":"2015","journal-title":"Dent. Mater."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"2038","DOI":"10.1039\/C4PY01582G","article-title":"Exploring the benefits of \u03b2-allyl sulfones for more homogeneous dimethacrylate photopolymer networks","volume":"6","author":"Gorsche","year":"2015","journal-title":"Polym. Chem."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"570","DOI":"10.1016\/j.dental.2020.02.007","article-title":"Outcomes of ultra-fast (3 s) photo-cure in a RAFT-modified resin-composite","volume":"36","author":"Ilie","year":"2020","journal-title":"Dent. Mater."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1266","DOI":"10.1016\/j.dental.2020.07.008","article-title":"Conversion kinetics of rapid photo-polymerized resin composites","volume":"36","author":"Algamaiah","year":"2020","journal-title":"Dent. Mater."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Negovetic Mandic, V., Par, M., Marovic, D., Raki\u0107, M., Tarle, Z., and Klari\u0107 Sever, E. (2023). Blue Laser for Polymerization of Bulk-Fill Composites: Influence on Polymerization Kinetics. Nanomaterials, 13.","DOI":"10.3390\/nano13020303"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"804","DOI":"10.1016\/j.dental.2005.11.009","article-title":"Curing-light attenuation in filled-resin restorative materials","volume":"22","author":"Musanje","year":"2006","journal-title":"Dent. Mater."},{"key":"ref_29","first-page":"410","article-title":"Influence of curing lights and modes on cross-link density of dental composites","volume":"29","author":"Yap","year":"2004","journal-title":"Oper. Dent."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"1849","DOI":"10.1038\/s41467-020-15669-z","article-title":"Origin of micro-scale heterogeneity in polymerisation of photo-activated resin composites","volume":"11","author":"Sirovica","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3561","DOI":"10.1007\/s10856-008-3520-4","article-title":"Effect of filler size and shape on local nanoindentation modulus of resin-composites","volume":"19","author":"Masouras","year":"2008","journal-title":"J. Mater. Sci. Mater. Med."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"364","DOI":"10.1111\/j.1365-2842.2010.02066.x","article-title":"Investigating filler morphology and mechanical properties of new low-shrinkage resin composite types","volume":"37","author":"Leprince","year":"2010","journal-title":"J. Oral Rehabil."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"115212","DOI":"10.1016\/j.envres.2023.115212","article-title":"Mechanically-robust electrospun nanocomposite fiber membranes for oil and water separation","volume":"220","author":"Nueraji","year":"2023","journal-title":"Environ. Res."},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Zhambolova, A., Vocaturo, A.L., Tileuberdi, Y., Ongarbayev, Y., Caputo, P., Aiello, I., Oliviero Rossi, C., and Godbert, N. (2020). Functionalization and Modification of Bitumen by Silica Nanoparticles. Appl. Sci., 10.","DOI":"10.3390\/app10176065"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1586","DOI":"10.1016\/j.dental.2016.09.034","article-title":"Filler characteristics of modern dental resin composites and their influence on physico-mechanical properties","volume":"32","author":"Randolph","year":"2016","journal-title":"Dent. Mater."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"51","DOI":"10.1016\/j.dental.2005.12.003","article-title":"Characterization of nanofilled compared to universal and microfilled composites","volume":"23","author":"Beun","year":"2007","journal-title":"Dent. Mater."},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Graf, N., and Ilie, N. (2020). Long-Term Stability of a RAFT-Modified Bulk-Fill Resin-Composite under Clinically Relevant Versus ISO-Curing Conditions. Materials, 13.","DOI":"10.3390\/ma13235350"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"e101","DOI":"10.1016\/j.dental.2016.11.013","article-title":"Laboratory mechanical parameters of composite resins and their relation to fractures and wear in clinical trials-A systematic review","volume":"33","author":"Heintze","year":"2017","journal-title":"Dent. Mater."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"993","DOI":"10.1016\/j.jdent.2014.05.009","article-title":"Physico-mechanical characteristics of commercially available bulk-fill composites","volume":"42","author":"Leprince","year":"2014","journal-title":"J. Dent."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1007\/s00784-016-1920-2","article-title":"How light attenuation and filler content affect the microhardness and polymerization shrinkage and translucency of bulk-fill composites?","volume":"21","author":"Son","year":"2017","journal-title":"Clin. Oral Investig."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"10560","DOI":"10.1038\/s41598-020-67641-y","article-title":"The effect of rapid high-intensity light-curing on micromechanical properties of bulk-fill and conventional resin composites","volume":"10","author":"Par","year":"2020","journal-title":"Sci. Rep."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"465","DOI":"10.3325\/cmj.2016.57.465","article-title":"Remineralizing amorphous calcium phosphate based composite resins: The influence of inert fillers on monomer conversion, polymerization shrinkage, and microhardness","volume":"57","author":"Demoli","year":"2016","journal-title":"Croat. Med. J."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"521","DOI":"10.1016\/j.dental.2012.02.002","article-title":"Depth of cure of resin composites: Is the ISO 4049 method suitable for bulk fill materials?","volume":"28","author":"Flury","year":"2012","journal-title":"Dent. Mater."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/16\/13\/4868\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:07:51Z","timestamp":1760126871000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/16\/13\/4868"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,7,7]]},"references-count":43,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2023,7]]}},"alternative-id":["ma16134868"],"URL":"https:\/\/doi.org\/10.3390\/ma16134868","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,7,7]]}}}