Effect of abutment screw channel angle and crown height on the screw stability of posterior monolithic zirconia crowns supported by tissue-level implants: An in vitro study.
Angled screw channel titanium-base (Ti-base) abutments have been introduced for unfavorably positioned implants. However, knowledge on their screw stability in situations with compromised crown height space is lacking. The purpose of this in vitro study was to evaluate the effect of abutment screw c...
| Publicado en: | Journal of Prosthetic Dentistry Vol. 136; no. 3; pp. 829 - 837 |
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| Autores principales: | , , , , |
| Formato: | research Journal Article |
| Publicado: |
Elsevier B.V.
Sep2026
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| Acceso en línea: | Ver este registro en EBSCOhost |
| fields | @attributes: recordID: 1 pdfLink: plink: https://search.ebscohost.com/login.aspx?direct=true&db=ccm&AN=196794556&site=ehost-live header: @attributes: shortDbName: ccm uiTerm: 196794556 longDbName: CINAHL Complete uiTag: AN controlInfo: bkinfo: dissinfo: jinfo: jid: 00223913 1ZB jtl: Journal of Prosthetic Dentistry issn: 00223913 maglogo: N pubinfo: dt: Sep2026 vid: 136 iid: 3 pid: 467 pub: Elsevier B.V. place: New York, New York artinfo: ui: 196794556 196794556 196794556 10.1016/j.prosdent.2026.05.033 196794556 ppf: 829 ppct: 8 formats: tig: atl: Effect of abutment screw channel angle and crown height on the screw stability of posterior monolithic zirconia crowns supported by tissue-level implants: An in vitro study. aug: au: Dönmez, Mustafa Borga Molinero-Mourelle, Pedro Çakmak, Gülce Schimmel, Martin Yilmaz, Burak affil: Associate Professor, Department of Prosthodontics, Faculty of Dentistry, Biruni University, Istanbul, Turkey sug: subj: Dental Abutments Dental Equipment Materials Testing Crowns Dental Materials Dental Implants Treatment Outcomes In Vitro Studies Dental Cements Torque Descriptive Statistics Two-Way Analysis of Variance ab: Angled screw channel titanium-base (Ti-base) abutments have been introduced for unfavorably positioned implants. However, knowledge on their screw stability in situations with compromised crown height space is lacking. The purpose of this in vitro study was to evaluate the effect of abutment screw channel angle and crown height on the screw stability of monolithic zirconia crowns supported by a recently introduced implant-abutment connection, both after 24 hours and cyclic loading. Forty tissue-level implants (TLX Standard Plus) were divided into subgroups according to Ti-base abutment screw channel angle (straight [S] or 25-degree angled [A]) and crown height (10 mm [S] or 15 mm [L]) (n =10). Monolithic zirconia screw-retained mandibular first molar crowns were milled for each configuration and cemented onto their corresponding Ti-base abutments. Initial torque values (ITVs) and removal torque values (RTVs) after 24 hours were recorded. The screws were then replaced with new ones, ITVs were recorded again, and the crowns were subjected to cyclic loading (2.4 million cycles at 98 N). Final RTVs were measured, and the percentage torque loss was calculated. All data were analyzed with 2-way analysis of variance tests to analyze the effect of abutment screw channel angle and crown height on ITVs, RTVs, and percentage torque loss (α=.05). No mechanical complications (screw loosening, decementation, or component fracture) occurred during testing. There were no significant differences among subgroups when ITVs, RTVs, and percentage torque loss were considered (P ≥.377). Mean ITVs ranged from 34.9 to 35.2 Ncm. Mean RTVs measured after 24 hours of passive settling (before cyclic loading) were 29.2 to 29.5 Ncm, whereas those measured after cyclic loading were 24.8 to 25.4 Ncm. Corresponding mean percentage torque loss was 15.9% to 16.4% at 24 hours and 27.7% to 29.3% after cyclic loading. No mechanical failures, screw loosening, or decementation occurred during cyclic loading, regardless of crown height or abutment screw channel angulation. These findings indicated the potential of tested implant-abutment connection and Ti-base abutment screw channel angles to be alternatives to treat situations with compromised crown height space up to 15 mm. pubtype: Academic Journal doctype: research Journal Article ougenre: Article language: English refInfo: holdings: @attributes: islocal: N |
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