{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T20:05:17Z","timestamp":1787169917546,"version":"build-2736575974"},"reference-count":19,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"4","content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2021,4]]},"abstract":"<jats:sec>\n                    <jats:title>Objective:<\/jats:title>\n                    <jats:p>To evaluate the effect of varying ferrule height and distribution on the fatigue resistance and fracture strength of endodontically treated premolars.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Materials and Method:<\/jats:title>\n                    <jats:p>\n                      Thirty-two extracted human premolars were endodontically treated and prepared to receive all-ceramic crowns. Teeth were randomly divided into two groups. The occluso-cervical height was reduced to 2 mm and 4 mm for the 1\n                      <jats:sup>st<\/jats:sup>\n                      and 2\n                      <jats:sup>nd<\/jats:sup>\n                      groups, respectively. According to the ferrule distribution, samples in each group were randomly divided into two subgroups with inadequate ferrule on 1 or 2 proximal walls, respectively. Coronal tooth structure was built-up to 4 mm using a core build-up material retained by a fiber post. The CEREC system (Sirona) was used to design and mill lithium-disilicate crowns. All posts and crowns were cemented to their respective teeth using self-adhesive universal resin cement. All crowns were subjected to cyclic loading in a universal testing machine (Instron) (20\u2013100N, 100,000 cycles, 20Hz). After fatigue, crowns were loaded to fracture. Fracture load data were analyzed using two-way ANOVA at \u03b1 = 0.05.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results:<\/jats:title>\n                    <jats:p>\n                      All crowns passed the fatigue testing without any signs of fracture or crack. Two-way ANOVA revealed a statistically significant effect of the number of missing walls (\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      &lt; 0.05) on the fracture load, but not the ferrule height or the interaction terms. Samples with one missing wall showed higher fracture load in comparison to samples with two missing walls.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusion:<\/jats:title>\n                    <jats:p>The number of missing walls, not the ferrule height, has a significant effect on the fracture load of the lithium-disilicate crowns restoring endodontically treated premolars.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.4103\/njcp.njcp_268_20","type":"journal-article","created":{"date-parts":[[2023,8,21]],"date-time":"2023-08-21T03:28:40Z","timestamp":1692588520000},"page":"505-510","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":2,"title":["Effect of Ferrule Height and Distribution on the Fracture Resistance of Endodontically Treated Premolars"],"prefix":"10.4103","volume":"24","author":[{"given":"M","family":"Zahran","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D","family":"Abderbwih","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H","family":"Mandourah","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"SB","family":"Afif","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D","family":"Sabbahi","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"K","family":"Merdad","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"H","family":"Sonbul","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","reference":[{"key":"R1-8-20240907","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1016\/j.joen.2009.12.002","article-title":"Identifying and reducing risks for potential fractures in endodontically treated teeth","volume":"36","author":"Tang","year":"2010","journal-title":"J Endod"},{"key":"R2-8-20240907","doi-asserted-by":"crossref","first-page":"951","DOI":"10.1111\/iej.12723","article-title":"Failure of single-unit restorations on root filled posterior teeth: A systematic review","volume":"50","author":"Afrashtehfar","year":"2017","journal-title":"Int Endod J"},{"key":"R3-8-20240907","doi-asserted-by":"crossref","first-page":"780","DOI":"10.1016\/0022-3913(84)90376-7","article-title":"Intracoronal reinforcement and coronal coverage: A study of endodontically treated teeth","volume":"51","author":"Sorensen","year":"1984","journal-title":"J Prosthet Dent"},{"key":"R4-8-20240907","doi-asserted-by":"crossref","first-page":"256","DOI":"10.1067\/mpr.2002.122014","article-title":"Relationship between crown placement and the survival of endodontically treated teeth","volume":"87","author":"Aquilino","year":"2002","journal-title":"J Prosthet Dent"},{"key":"R5-8-20240907","doi-asserted-by":"crossref","first-page":"529","DOI":"10.1016\/0022-3913(90)90070-S","article-title":"Ferrule design and fracture resistance of endodontically treated teeth","volume":"63","author":"Sorensen","year":"1990","journal-title":"J Prosthet Dent"},{"key":"R7-8-20240907","first-page":"78","article-title":"The influence of post length and crown ferrule length on the resistance to cyclic loading of bovine teeth with prefabricated titanium posts","volume":"12","author":"Isidor","year":"1999","journal-title":"Int J Prosthodont"},{"key":"R8-8-20240907","doi-asserted-by":"crossref","first-page":"290","DOI":"10.1016\/j.prosdent.2006.02.026","article-title":"Influence of remaining coronal tooth structure location on the fracture resistance of restored endodontically treated anterior teeth","volume":"95","author":"Ng","year":"2006","journal-title":"J Prosthet Dent"},{"key":"R9-8-20240907","doi-asserted-by":"crossref","first-page":"1280","DOI":"10.1016\/j.dental.2013.10.003","article-title":"The influence of substance loss and ferrule height on the fracture resistance of endodontically treated premolars. 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