{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,26]],"date-time":"2026-10-26T23:01:12Z","timestamp":1793055672595,"version":"4.5.0"},"reference-count":43,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2023,12,7]],"date-time":"2023-12-07T00:00:00Z","timestamp":1701907200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Journal of Prosthodontics"],"published-print":{"date-parts":[[2025,2]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Purpose<\/jats:title><jats:p>The design of the angulated screw channel in implant restorations allows the possibility to correct angulation discrepancies, especially in the anterior maxilla. However, the effects of varied screw channel angulations on fracture resistances and fracture patterns of the implant restorations are still uncertain, and thus the aim of this study.<\/jats:p><\/jats:sec><jats:sec><jats:title>Materials and Methods<\/jats:title><jats:p>Angulated screw channel monolithic zirconia crowns (Nobel Biocare) with three different angulation groups\u2014straight (ASC1), 15\u00b0 (ASC15), and 25\u00b0 (ASC25)\u2014were digitally designed from a left central incisor prototype scan. Following fabrication, 10 samples of each group were individually mounted onto implant replicas embedded in standardized type V stone gypsum cylinder jigs (25\u00a0mm \u00d7 25\u00a0mm). All screws were manually torqued to 35 Ncm according to the manufacturer's recommendation, and screw access openings were subsequently sealed with resin composite. To mimic the off\u2010axis loading of the central incisor, the specimens were then loaded at a cephalometric interincisal relationship of 135\u00b0 between the long axis of the crown and the Instron force applicator, with crosshead speed set at 0.5\u00a0mm\/min. Fractured abutment surfaces were examined, and selected specimens were further evaluated by scanning electron microscopy. Screw torque values were also measured after the catastrophic loading. One\u2010way ANOVA was used to compare load\u2010to\u2010fracture values between groups, with the statistical significance set at 0.05 (<jats:italic>p<\/jats:italic> values).<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The mean load\u2010to\u2010fracture values in descending order were 331.24N (\u00b134.00N) in ASC15, 325.22N (\u00b135.50N) in ASC25, and 302.04N (\u00b145.10N) in ASC1, with no statistically significant differences between groups. Considerable screw torque losses were found in all groups after catastrophically loading. The average torque loss was 84% in ASC1, 86% in ASC15, and 94% in ASC25. 16 out of 30 specimens experienced screw loosening; one ASC1 screw underwent slight deformation. Crowns of all tested groups exhibited cohesive fracture patterns at the screw\u2010metallic\u2010zirconia interfaces.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Within the limitations of this in vitro study, one\u2010piece monolithic zirconia implant crowns with varied screw channel angulations shared similar fracture\u2010strength and fracture\u2010mode characteristics. The zirconia\u2010titanium base junctions exhibited the weakest link of all restorations.<\/jats:p><\/jats:sec>","DOI":"10.1111\/jopr.13806","type":"journal-article","created":{"date-parts":[[2023,11,21]],"date-time":"2023-11-21T14:24:28Z","timestamp":1700576668000},"page":"167-173","update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Effects of screw channel angulation on the fracture resistance of one\u2010piece zirconia crown with titanium base"],"prefix":"10.1111","volume":"34","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0747-8114","authenticated-orcid":false,"given":"Chen\u2010xuan","family":"Wei","sequence":"first","affiliation":[{"name":"Department of Biologic and Materials Sciences and Prosthodontics University of Michigan  Ann Arbor Michigan USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Berna","family":"Saglik","sequence":"additional","affiliation":[{"name":"Department of Biologic and Materials Sciences and Prosthodontics University of Michigan  Ann Arbor Michigan USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hsiao Hsin","family":"Sung Hsieh","sequence":"additional","affiliation":[{"name":"Department of Oral &amp; Maxillofacial Surgery \/ Hospital Dentistry University of Michigan  Ann Arbor Michigan USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paramvir Singh J.","family":"Guram","sequence":"additional","affiliation":[{"name":"Department of Cariology Restorative Sciences and Endodontics University of Michigan  Ann Arbor Michigan USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2023,12,7]]},"reference":[{"key":"e_1_2_8_2_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1708-8240.2004.tb00028.x"},{"key":"e_1_2_8_3_1","doi-asserted-by":"publisher","DOI":"10.1097\/ID.0b013e3181bb9033"},{"key":"e_1_2_8_4_1","volume-title":"Adjustable\u2010angulation pattern 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