Eight-year clinical performance of cantilevered zirconia resin-bonded fixed dental prostheses : a randomized controlled trial evaluating the effect of nanostructured alumina coating

Malgaj, Tine (author), Kocjan, Andraž (author), Özcan, Mutlu (author), Jevnikar, Peter (author)

Objective. To evaluate the clinical performance of cantilevered zirconia resin-bonded fixed dental prostheses (RBFDPs) pretreated with nanostructured alumina coating (NAC) as a non-invasive surface modification alternative to airborne-particle abrasion (APA). Materials and Methods. In this prospective, randomized, controlled clinical trial, 57 patients requiring replacement of a maxillary or mandibular incisor received 64 zirconia RBFDPs, randomly assigned to APA (n = 32) or NAC (n = 32) groups. APA surfaces were air-abraded with 50-μm alumina, whereas NAC surfaces were coated with NAC. Restorations were further classified by pontic position. Retention and survival rates were analyzed using Kaplan–Meier and log-rank tests; patient-specific factors were assessed with Mann–Whitney U and Fisher's exact tests (α = 0.05). Debonded surfaces were examined under scanning electron microscopy. Results. Over a mean observation period of 61.4 ± 22.1 months (range, 8.3–97.4 months), six debondings occurred, corresponding to an overall survival rate of 100% and retention rates of 88.4% for NAC and 89.1% for APA (p = 0.99), with no significant differences among pontic groups (p = 0.18). Failures were predominantly adhesive, characterized by partial coating delamination at the NAC–zirconia interface. Conclusions. NAC-pretreated zirconia RBFDPs achieved mid- to long-term retention comparable to APA and represent a minimally invasive, clinically reliable pretreatment alternative. Clinical Significance. NAC provides a minimally invasive zirconia pretreatment, particularly for RBFDPs fabricated from damage-prone translucent zirconia, mitigating mechanical failures while maintaining long-term retention comparable to APA.

• Language: English
• Keywords: airborne-particle abrasion, bond strength, nanostructured alumina coating, randomized controlled clinical trial, resin-bonded fixeddental prostheses, zirc
• Typology: 1.01 - Original Scientific Article
• Organization: MF - Faculty of Medicine
• Publication version: Version of Record
• Publication date: 01.07.2026
• Year: 2026
• Number of pages: Str. 1386-1394
• Numbering: Vol. 38, iss. 7
• PID: 20.500.12556/RUL-184596
• UDC: 620.1/.2
• ISSN on article: 1708-8240
• DOI: 10.1111/jerd.70130
• COBISS.SI-ID: 271258371
• Publication date in RUL: 10.07.2026

Record is a part of a journal

• Title: Journal of esthetic and restorative dentistry
• Publisher: Wiley & Sons
• ISSN: 1708-8240
• COBISS.SI-ID: 3185684

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Projects

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: P2-0087
• Name: Keramični in komplementarni materiali za napredne inženirske in biomedicinske aplikacije

• Funder: ARIS - Slovenian Research and Innovation Agency
• Project number: J3-3064
• Name: Predklinične in Klinične Raziskave Cirkonijeve Oksidne Dentalne Keramike Izdelane s Tehnologijami Aditivnega Oblikovanja (ZIRAMDENT)