Intraoral repair of chipped or fractured veneered zirconia crowns and fixed dental prosthesis: clinical guidelines based on literature review

This article aimed to review the susceptibility to chipping, influencing factors, current protocols for intraoral repair and provide the clinicians with guidelines for repairing. Peer-reviewed literature in English published between 01/01/2000 and 30/06/2017 was electronically searched using PubMed and Google Scholar, followed by manual search of the scientific literature. Multiple key words and their combinations (‘Zirconium’, ‘Zirconia’, ‘Intraoral’, ‘Repair’, ‘Chipping’, ‘Fracture’, ‘Bonding’, and ‘Surface treatment’) and different search strategies were employed for sample selection. The initial search resulted in 189 articles, of which 98 were included in this review. The chipping rates of veneered zirconia-based restorations have been reported range between 0 and 44%. Researchers and clinicians were in favor of the intraoral repair of chipped veneered zirconia-based restorations. While various intraoral repair protocols were available based on the severity of chipping, decisions about intraoral repair were based on the clinical situation, availability/accessibility of repair kits, survival/success rate of repairing, and patient concerns. Intraoral repair seems to be a promising option to correct moderate size of chipping, and its success largely depends on the surface treatment methods used for the fractured surfaces. Hydrofluoric acid etching of the veneering porcelain followed by silanization and air-abrasion of the zirconia framework and then MDP priming have been recommended to create durable bonds. This review suggests that intraoral repair of chipped zirconia-based restorations offers a satisfying option for the patient when restoration replacement is not an option. Treatments for the fracture surface are the most important factors influencing the longevity of repaired zirconia-based restorations