{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,10]],"date-time":"2026-04-10T00:25:01Z","timestamp":1775780701841,"version":"3.50.1"},"reference-count":42,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2025,1,27]],"date-time":"2025-01-27T00:00:00Z","timestamp":1737936000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,1,27]],"date-time":"2025-01-27T00:00:00Z","timestamp":1737936000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"name":"Fayoum University"}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["BMC Oral Health"],"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>The purpose of this study was to evaluate the effect of different preparation depths (0, 2 and 4\u00a0mm) of different restoration designs (classic endocrown design versus overlay design) on marginal adaptation of restorations fabricated of two different restorative materials (lithium disilicate and PEEK).<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Materials and methods<\/jats:title>\n                    <jats:p>Sixty mandibular natural molars were collected as abutments for the restorations of this study, and grouped in three main groups of different cavity depths (0, 2 and 4). Each group was divided into two subgroups according to material of fabrication to (L) for lithium disilicate (IPS emax CAD, Ivoclar vivadent, Switzarland) and (P) for PEEK (Bio-hpp, Bredent, Germany). CAD\/CAM milling technology was used for fabrication of restorations. After cementation of restorations over abutments, hydrothermal aging was performed, and then marginal adaptation was evaluated via micro CT technology.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Regarding cavity depths, there was a significant difference between different groups (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001). The highest value was found in samples with 4\u00a0mm extension (84.35\u2009\u00b1\u200918.16), followed by samples with 2\u00a0mm extension (66.52\u2009\u00b1\u200921.86), while the lowest value was found in samples without pulpal extension (59.41\u2009\u00b1\u200922.16). Post hoc pairwise comparisons showed samples with 4\u00a0mm extension to have a significantly higher value than samples without extension (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001). Regarding materials of fabrication, PEEK (85.32\u2009\u00b1\u200912.37) had a significantly higher value than Emax (54.86\u2009\u00b1\u200920.86) (\n                      <jats:italic>p<\/jats:italic>\n                      \u2009&lt;\u20090.001).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Increasing intrapulpal cavity depths increases vertical marginal gap of lithium disilicate or PEEK restorations. Endocrowns fabricated of lithium disilicate show less marginal discrepancies than that of endocrowns fabricated of PEEK.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1186\/s12903-025-05474-9","type":"journal-article","created":{"date-parts":[[2025,1,27]],"date-time":"2025-01-27T07:36:27Z","timestamp":1737963387000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Micro CT evaluation of marginal discrepancies of endocrown restored molars with different intrapulpal depths and materials of fabrication. (in-vitro study)"],"prefix":"10.1186","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7006-3726","authenticated-orcid":false,"given":"Mohamed Aly Mohamed Badr","family":"Elagwany","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Amina Mohamed","family":"Hamdy","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maged Mohamed","family":"Zohdy","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7910-9759","authenticated-orcid":false,"given":"Aliaa","family":"Mahrous","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ahmed","family":"Tawfik","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8296-3403","authenticated-orcid":false,"given":"Soha Osama","family":"Nabih","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"297","published-online":{"date-parts":[[2025,1,27]]},"reference":[{"key":"5474_CR1","doi-asserted-by":"publisher","first-page":"306","DOI":"10.1016\/j.jmbbm.2018.10.030","volume":"90","author":"R Schestatsky","year":"2019","unstructured":"Schestatsky R, Dartora G, Felberg R, Spazzin AO, Sarkis-Onofre R, Bacchi APG. Do endodontic retreatment techniques influence the fracture strength of endodontically treated teeth? A systematic review and meta-analysis. J Mech Behav Biomed Mater. 2019;90:306\u201312.","journal-title":"J Mech Behav Biomed Mater"},{"issue":"2","key":"5474_CR2","doi-asserted-by":"publisher","first-page":"176","DOI":"10.11607\/ijp.6090","volume":"33","author":"ZY Phang","year":"2020","unstructured":"Phang ZY, Quek SHQ, Teoh KH, Tan KBCTK. A retrospective study on the success, survival, and incidence of complications of post-retained restorations in premolars supporting fixed dental prostheses with a mean of 7 years in function. Int J Prosthodont. 2020;33(2):176\u201383.","journal-title":"Int J Prosthodont"},{"key":"5474_CR3","doi-asserted-by":"publisher","first-page":"8","DOI":"10.1016\/j.jdent.2016.07.005","volume":"52","author":"JA Sedrez-Porto","year":"2016","unstructured":"Sedrez-Porto JA, Rosa WL, da Silva AF. Munchow EA P-CT. Endocrown restorations: a systematic review and meta-analysis. J Dent. 2016;52:8\u201314.","journal-title":"J Dent"},{"issue":"3","key":"5474_CR4","doi-asserted-by":"publisher","first-page":"411","DOI":"10.1016\/j.prosdent.2019.04.009","volume":"123","author":"NCME Govare","year":"2020","unstructured":"Govare NCME. Endocrowns: a systematic review. J Prosthet Dent. 2020;123(3):411\u20138.","journal-title":"J Prosthet Dent"},{"key":"5474_CR5","doi-asserted-by":"publisher","first-page":"103","DOI":"10.1016\/j.jmbbm.2019.103592","volume":"103","author":"JA Sedrez-Porto","year":"2020","unstructured":"Sedrez-Porto JA, Munchow EA, Cenci MS, P-CT. Which materials would account for a better mechanical behavior for direct endocrown restorations? J Mech Behav Biomed Mater. 2020;103:103\u201392.","journal-title":"J Mech Behav Biomed Mater"},{"issue":"6","key":"5474_CR6","doi-asserted-by":"publisher","first-page":"489","DOI":"10.4047\/jap.2016.8.6.489","volume":"8","author":"J Guo","year":"2016","unstructured":"Guo J, Wang Z, Li X, Sun C, Gao ELH. A comparison of the fracture resistances of endodontically treated mandibular premolars restored with endocrowns and glass fiber post-core retained conventional crowns. J Adv Prosthodont. 2016;8(6):489\u201393.","journal-title":"J Adv Prosthodont"},{"key":"5474_CR7","unstructured":"of Fabrication P P. A metal-free ceramic restoration utilizing the monobloc technique. Pr Periodontics Aesthet Dent. 1995;7(5):83\u201394."},{"issue":"3","key":"5474_CR8","first-page":"255","volume":"1","author":"AMW Bindl","year":"1999","unstructured":"Bindl AMW. Clinical evaluation of adhesively placed Cerec endo-crowns after 2 years\u2013preliminary results. J Adhes Dent. 1999;1(3):255\u201365.","journal-title":"J Adhes Dent"},{"key":"5474_CR9","doi-asserted-by":"crossref","unstructured":"Magne P, Carvalho AO, Bruzi G, Anderson RE, Maia HPGM. Influence of no ferrufe and no-Post buildup design on the fatigue resistance of endodontically treated molars restored with resin nanoceramic CAD\/CAM crowns. Oper Dent 2014; 39595\u2013602.","DOI":"10.2341\/13-004-L"},{"key":"5474_CR10","doi-asserted-by":"crossref","unstructured":"Forberger NGI. Influence of the type of post and core on in vitro marginal continuity, fracture resistance, and fracture mode of lithia disilicate-based all-ceramic crowns. J Prosthet Dent 2008; 100264\u2013273.","DOI":"10.1016\/S0022-3913(08)60205-X"},{"key":"5474_CR11","doi-asserted-by":"publisher","first-page":"109","DOI":"10.1016\/j.prosdent.2016.03.025","volume":"117","author":"Y Shin","year":"2017","unstructured":"Shin Y, Park S, Park JW, Kim KMPY. Evaluation of the marginal and internal discrepancies of CAD-CAM endocrowns with different cavity depths: an in vitro study. J Prosthet Dent. 2017;117:109\u201315.","journal-title":"J Prosthet Dent"},{"key":"5474_CR12","doi-asserted-by":"crossref","unstructured":"HM. GMD and E-D. Effect of Preparation depth on the marginal and internal adaptation of computer-aided Design\/Computer-assisted manufacture endocrowns. Oper Dent 2016; 41 607\u201316.","DOI":"10.2341\/15-146-L"},{"issue":"2","key":"5474_CR13","doi-asserted-by":"publisher","first-page":"130","DOI":"10.2341\/11-105-L","volume":"37","author":"GRBR Biacchi","year":"2012","unstructured":"Biacchi GRBR. Comparison of fracture strength of endocrownsand glass fiber post-relained conventional crowns. Oper Dent. 2012;37(2):130\u20136.","journal-title":"Oper Dent"},{"issue":"4","key":"5474_CR14","first-page":"333","volume":"11","author":"WH M\u00f6rmann","year":"1998","unstructured":"M\u00f6rmann WH, Bindl A, L\u00fcthy HRA. Effects of preparation and luting system on all-ceramic computer-generated crowns. Int J Prosthodont. 1998;11(4):333\u20139.","journal-title":"Int J Prosthodont"},{"key":"5474_CR15","doi-asserted-by":"crossref","unstructured":"Zoidis P, Bakiri EPG. Using modified polyetheretherketone (PEEK) as an alternative material for endocrown restorations: a short-term clinical report. J Prosthet Dent 2017,117335\u2013339.","DOI":"10.1016\/j.prosdent.2016.08.009"},{"key":"5474_CR16","unstructured":"Aktas G, Yerlikaya HAK. Mechanical failure of endocrowns manufactured with different ceramic materials: an in vitro biomechanical study. J Prosthodont 2018;27340\u2013346."},{"key":"5474_CR17","doi-asserted-by":"crossref","unstructured":"Stawarczyk B, Thrun H, Eichberger M, Roos M, Edelhoff D, Schweiger J et al. Effect of different surface pretreatments and adhesives on the load-bearing capacity of veneered 3-unit PEEK FDPs. J Prosthet Dent 2015, 114666\u2013673.","DOI":"10.1016\/j.prosdent.2015.06.006"},{"key":"5474_CR42","doi-asserted-by":"publisher","unstructured":"Nagi N, Fouda AM, Bourauel C. Comparative evaluation of internal fit and marginal gap of endocrowns using lithium disilicate and polyether ether ketone materials - an in vitro study Abstract BMC Oral Health 2023;23(1):207. https:\/\/doi.org\/10.1186\/s12903-023-02857-8","DOI":"10.1186\/s12903-023-02857-8"},{"key":"5474_CR18","unstructured":"Dalloul RANJ. and A-HN. A comparative study of marginal fit between IPS e.max Press Crown and Endocrown after Cementation (in Vitro). Clin Med Diagn J 2016; 6 122\u2009\u2013\u200925."},{"issue":"2","key":"5474_CR19","doi-asserted-by":"publisher","first-page":"116","DOI":"10.1111\/j.1365-2842.2003.01203.x","volume":"35","author":"M Laurent","year":"2008","unstructured":"Laurent M, Scheer P, Dejou J. Clinical evaluation of the marginal fit of cast crowns\u2014validation of the silicone replica method. J Oral Rehab. 2008;35(2):116\u201322.","journal-title":"J Oral Rehab"},{"key":"5474_CR20","unstructured":"JW M. The estimation of cement film thickness by an in vIvo technique. Br dent j 1971; 131107\u2013111."},{"issue":"2","key":"5474_CR21","doi-asserted-by":"publisher","first-page":"551","DOI":"10.1007\/s00784-016-1916-y","volume":"21","author":"C Kirsch","year":"2017","unstructured":"Kirsch C, Ender A, Attin TMA. Trueness of four different milling procedures used in dental CAD\/CAM systems. Clin O Investig. 2017;21(2):551\u20138.","journal-title":"Clin O Investig"},{"issue":"4","key":"5474_CR22","doi-asserted-by":"publisher","first-page":"551","DOI":"10.1016\/j.prosdent.2016.03.028","volume":"116","author":"JH Kim","year":"2016","unstructured":"Kim JH, Jeong JH, Lee JHCH. Fit of lithium disilicate crowns fabricated from conventional and digital impressions assessed with micro-CT. J Prosthet dent. 2016;116(4):551\u20137.","journal-title":"J Prosthet dent"},{"issue":"3","key":"5474_CR23","first-page":"278","volume":"4","author":"S Pelekanos","year":"2009","unstructured":"Pelekanos S, Koumanou M, Koutayas SO, Zinelis S. Micro-CT evaluation of the marginal fit of different In-Ceram alumina copings. Eur J Esthet Dent. 2009;4(3):278\u201392.","journal-title":"Eur J Esthet Dent"},{"issue":"5","key":"5474_CR24","doi-asserted-by":"publisher","first-page":"396","DOI":"10.1590\/S1806-83242013000500003","volume":"27","author":"M Borba","year":"2013","unstructured":"Borba M, Miranda WG Jr., Cesar PF, Griggs JA. Evaluation of the adaptation of zirconia-based fixed partial dentures using micro-CT technology. Braz O Res. 2013;27(5):396\u2013402.","journal-title":"Braz O Res"},{"issue":"6","key":"5474_CR25","doi-asserted-by":"publisher","first-page":"558","DOI":"10.1016\/j.archoralbio.2007.11.011","volume":"53","author":"P Gielkens","year":"2008","unstructured":"Gielkens P, de Schortinghuis J. A comparison of micro-CT, microradiography and histomorphometry in bone research. Arch Oral Biol. 2008;53(6):558\u201366.","journal-title":"Arch Oral Biol"},{"issue":"5","key":"5474_CR26","doi-asserted-by":"publisher","first-page":"1134","DOI":"10.1016\/j.prosdent.2014.04.028","volume":"112","author":"FD Neves","year":"2014","unstructured":"Neves FD, Prado CJ. Micro-computed tomography evaluation of marginal fit of lithium disilicate crowns fabricated by using chairside CAD\/CAM systems or the heat-pressing technique. J Prosthet Dent. 2014;112(5):1134\u201340.","journal-title":"J Prosthet Dent"},{"key":"5474_CR27","doi-asserted-by":"publisher","first-page":"374","DOI":"10.1016\/j.jdent.2009.01.008","volume":"37","author":"D Seo","year":"2009","unstructured":"Seo D, Yi YRB. The effect of preparation designs on the marginal and internal gaps in CEREC3 partial ceramic crowns. J Dent. 2009;37:374\u201382.","journal-title":"J Dent"},{"issue":"6","key":"5474_CR28","doi-asserted-by":"publisher","first-page":"444","DOI":"10.4047\/jap.2014.6.6.444","volume":"6","author":"SR Habib","year":"2014","unstructured":"Habib SR, Asiri W. Effect of anatomic, semi anatomic and non-anatomic occlusal surface tooth preparations on the adaptation of zirconia copings. J Adv Prosthodont. 2014;6(6):444\u201350.","journal-title":"J Adv Prosthodont"},{"key":"5474_CR29","doi-asserted-by":"crossref","unstructured":"Yooseok Shin S, Park J-W, Park -Mahn, Kim Y-B, Park. and B-DR. Evaluation of the marginal and internal discrepancies of CAD-CAM endocrowns with different cavity depths: an in vitro study. J Prosthet Dent 2017 117(1) 109\u201315.","DOI":"10.1016\/j.prosdent.2016.03.025"},{"issue":"5","key":"5474_CR30","first-page":"481","volume":"29","author":"J Manhart","year":"2004","unstructured":"Manhart J, Chen H, Hamm GHRBML. Review of the clinical survival of direct and indirect restorations in posterior teeth of the permanent dentition. Oper Dent. 2004;29(5):481\u2013506.","journal-title":"Oper Dent"},{"issue":"1","key":"5474_CR31","doi-asserted-by":"publisher","first-page":"87","DOI":"10.1016\/j.dental.2011.09.003","volume":"28","author":"FF Demarco","year":"2012","unstructured":"Demarco FF, Correa MB, Cenci MS, Moraes ARON. Longevity of posterior composite restorations: not only a matter of materials. Dent Mater. 2012;28(1):87\u2013101.","journal-title":"Dent Mater"},{"key":"5474_CR37","unstructured":"(2008) 109. ISO-Standerd. ISO 13356 Dental materials:implants for surgery-ceramic materials based on ytrria-stabilized tetragonal zirconia (Y-TZP): Geneve. Int Organ Stand."},{"issue":"1","key":"5474_CR32","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jdent.2004.11.001","volume":"33","author":"SF Chuang","year":"2005","unstructured":"Chuang SF, Chang CH, Yaman PCLT. Influence of enamel wetness on resin composite restorations using various dentine bonding agents: part I - effects on marginal quality and enamel microcrack formation. J Dent. 2005;33(1):1\u20139.","journal-title":"J Dent"},{"issue":"2","key":"5474_CR33","first-page":"190","volume":"24","author":"AZ Godil","year":"2021","unstructured":"Godil AZ, Kazi AI, Wadwan SA, Gandhi KY, Dugal RJS. Comparative evaluation of marginal and internal fit of endocrowns using lithium disilicate and polyetheretherketone computer-aided design - computer-aided manufacturing (CAD-CAM) materials: an in vitro study. J Conserv dent. 2021;24(2):190.","journal-title":"J Conserv dent"},{"key":"5474_CR34","unstructured":"OH K, DH K. SH P. The influence of elastic modulus of base material on the marginal adaptation of direct composite restoration. Oper dent 2010; 35441\u2013447."},{"key":"5474_CR38","doi-asserted-by":"crossref","unstructured":"Meshreky M, C H. H. K. Vertical marginal gap distance of CAD\/CAM milled BioHPP PEEK coping veneered by HIPC compared to zirconia coping veneered by CAD-On lithium disilicate in-vitro study. Adv Dent J 2020;243\u201350.","DOI":"10.21608\/adjc.2020.21032.1043"},{"key":"5474_CR35","doi-asserted-by":"crossref","unstructured":"Stawarczyk B, Jordan P, Schmidlin PR, Roos M, Eichberger M, Gernet W et al. PEEK surface treatment effects on tensile bond strength to veneering resins. J Prosthet Dent 2014;1121278\u20131288.","DOI":"10.1016\/j.prosdent.2014.05.014"},{"key":"5474_CR40","doi-asserted-by":"crossref","unstructured":"Osman AM, Mahallawi E, Khair-Allah OS, L. S., Khodary E. NA. Marginal integrity and clinical evaluation of polyetheretherketone (PEEK) versus lithium disilicate (E-Max) endocrowns: Randomized controlled clinical trial. Int J Heal Sci 6(s4), 1831\u201345.","DOI":"10.53730\/ijhs.v6nS4.6322"},{"key":"5474_CR36","unstructured":"Wagner C, Stock V, Merk S, Schmidlin PR, Roos M, Eichberger M et al. Retention load of telescopic crowns with different taper angles between cobalt-chromium and polyetheretherketone made with three different manufacturing processes examined by pull-off test. J Prosthodont 2018;27162\u2013168."},{"key":"5474_CR39","doi-asserted-by":"crossref","unstructured":"Hasanzade M, Sahebi M, Zarrati S, Payaminia LAM. Comparative evaluation of the internal and marginal adaptations of CAD\/CAM endocrowns and crowns fabricated from three different materials. Int J Prosthodont 2020 Dec 19.","DOI":"10.11607\/ijp.6389"},{"key":"5474_CR41","doi-asserted-by":"crossref","unstructured":"Nakamura T, Dei N, Kojima TWK. Marginal and internal fit of Cerec 3 CAD\/CAM all-ceramic crowns. Int J Prosthodont 2003; 116.","DOI":"10.2186\/prp.3.92"}],"container-title":["BMC Oral Health"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12903-025-05474-9.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1186\/s12903-025-05474-9\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12903-025-05474-9.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,1,27]],"date-time":"2025-01-27T07:36:37Z","timestamp":1737963397000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmcoralhealth.biomedcentral.com\/articles\/10.1186\/s12903-025-05474-9"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,1,27]]},"references-count":42,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["5474"],"URL":"https:\/\/doi.org\/10.1186\/s12903-025-05474-9","relation":{"has-preprint":[{"id-type":"doi","id":"10.21203\/rs.3.rs-3132905\/v1","asserted-by":"object"}]},"ISSN":["1472-6831"],"issn-type":[{"value":"1472-6831","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,1,27]]},"assertion":[{"value":"2 July 2023","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"10 January 2025","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"27 January 2025","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"The Research Ethics committee, Faculty of dentistry, Ain Shams University approved all experimental methods and the study was performed in accordance with its regulations, licensing requirements and relevant guidelines. Because this study did not contain any intervention with human participants or animals and it only utilized archival teeth whose owners cannot be identified, it was exempt from ethical assessment. The approval of the ethics committee is Fdasu-RecD031819. The need for informed consent was waived by the ethical committee of the Ain Shams University, Cairo, Egypt.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"Not applicable.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"The authors declare no competing interests.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"142"}}