Retrospective clinical study of 1472-unit monolithic zirconia restorations with feather-edge margins realized with digital workflow

• Published in: Clinical oral investigations 2023-11, Vol.27 (11), p.6567-6575
• Main Authors: Di Fiore, Adolfo, Monaco, Carlo, Stellini, Edoardo
• Format: Article
• Language: English
• Subjects: Biological Products; Computer-Aided Design; Crowns; Dental enamel; Dental Restoration Failure; Dentistry; Female; Gum disease; Humans; Informed consent; Male; Medicine; Prostheses; Prosthodontics; Retrospective Studies; Workflow; Zirconia; Zirconium
• ISSN: 1436-3771; 1432-6981; 1436-3771
• DOI: 10.1007/s00784-023-05262-1

Objectives To evaluate the clinical performance of monolithic zirconia restorations with feather-edge margins fabricated by digital impressions. Materials and methods All participants that present monolithic zirconia restorations with feather-edge margins realized with digital workflow were evaluated during scheduled periodontal maintenance between February and September 2022 according to predetermined inclusion criteria. Clinical performance was assessed using the modified USPHS and periodontal parameters. Overall survival was calculated for monolithic zirconia restorations. Technical and biologic complications were reported. Descriptive statistical analysis and life-table analyses were performed for all data. Results A total of 1472 monolithic zirconia FDPs (1279 on abutments and 193 on pontics) placed in 1189 patients (982 males and 490 females) from February 2017 to September 2020 were analyzed. The mean follow-up was 44 months (range 36–61 months), and the overall survival rate was 98.5%. There were 931 single crowns, 96 were 3-unit FDPs, 33 were 4-unit FDPs, 11 were 5-unit FDPs, and 6-unit FDPs. Three single crowns had irreparable cracks, and 6 single crowns and one 4-unit FDP were fractured. One 3-unit FDP failed due to tooth fracture and 5 single crowns failed due to endodontic failure. The loss of retention was noted in 25 monolithic zirconia FDPs and hypersensitivity in 44 single crowns. Biologic complications were uncommon. Conclusions Based on the results and its limitations, the monolithic zirconia FPDs and digital impressions represent a favorable prosthetic treatment similar to that reported with other margin designs Clinical relevance Monolithic zirconia restorations on vertical-margin abutments fabricated using a digital workflow demonstrate excellent clinical performance. The digital clinical workflow without the use of a cast means a reduction in costs, steps, and operating time.