Comparing the Repair of Veneered Zirconia Crowns with Ceramic or Composite Resin: An in Vitro Study

Abstract

Statement of problem: Current techniques for repairing porcelain-chipped restorations have several limitations. With advances in CAD/CAM technology, the combination of resin cements and high-strength ceramic materials might offer new options for repairing the chipping of veneering ceramic. Purpose: The purpose of this study is to compare the load-to-failure of veneered zirconia crowns repaired by different materials. Material and Methods: Veneered zirconia crowns were made on aluminum dies (n = 10/group). Feldspathic porcelain (Vita VM9, Vident) was applied to the zirconia coping (Vita In-Ceram YZ, Vident) in a cylindrical shape (Ø 10.5 mm, height 7.5 mm). A bevel cut on the porcelain veneer (45 degree, 3 mm width) was made at one side of each crown to simulate porcelain chipping. The crowns were then divided into four different groups according to the repair materials: 1. Conventional resin composite (A; Tetric EvoCeram, Ivoclar Vivadent); 2. Flowable resin composite (B; G-aenial Universal Flo, GC america); 3. CAD/CAM milled feldspathic ceramic (C; Vita Trilux Forte, Vident); 4. CAD/CAM milled lithium disilicate glass-ceramic (D; IPS e.max CAD, Ivoclar Vivadent). Resin cement (Multilink Automix, Ivoclar Vivadent) was used to cement the CAD/CAM ceramic materials to the beveled crowns. Each crown underwent 5000 cycles of thermocycling. The strength test was performed on an Instron universal testing machine by loading force on the center of repaired part to record load-to-failure. Data were analyzed by ANOVA and Tukey HSD post-hoc tests (α = 0.05). Results: Mean loads-to-failure (in Newton +/− SD) of repaired veneered zirconia crowns were: Gr. A: 660.0 ± 200.5; Gr. B: 681.7 ± 175.9; Gr. C: 1236.0 ± 188.8; Gr. D: 1536.3 ± 286.1. Catastrophic failure was the most dominant failure mode in every group. Few specimens exhibited cohesive failure. Only one specimen in group D had adhesive failure. Conclusions: Within the limitation of the study, veneered zirconia crowns repaired with CAD/CAM ceramic materials have significantly higher load-to-failure than veneered crowns repaired with resin composite (p ≤ 0.05). Clinical Implications: Traditionally, porcelain-chipped restorations are often repaired with resin composite and bonding technique. Repairing chipped porcelain with CAD/CAM ceramics fitting the fractured parts can be alternative option with potential advantages. More well-designed studies are necessary to justify this novel repair technique.

Assessment of Intra-Oral Repair Systems for Veneered Zirconia and Zirconia Only

“…As another intraoral repair system, the repair method with laminate veneers, also known as indirect facet application, has a higher success rate than composite resins in which the direct repair method is used, especially in cases where the ceramic contains large fractures [ 59 ]. The fact that the aesthetic properties of full ceramics are more favorable than composite resins, that they show color stability and are not corroded, and that their bonding to the substructure in repair is sufficient in previous studies, has led to the thought that the application of porcelain repair with laminate veneers may increase in clinical use [ 13 ] Porcelain laminates are aesthetically superior materials with long-term and predictable results with appropriate patient selection and experienced technicians [ 60 ].…”

Comparison of Mechanical Properties of Chairside CAD/CAM Restorations Fabricated Using a Standardization Method

“…Hydrofluoric acid etches the surface of the porcelain to create micro-porosities that facilitate micromechanical and chemical bonding between the ceramic and resin materials. Silane coupling agents promote adhesion and form a chemical bond with organic and inorganic surfaces, thereby increasing the wettability of the ceramic surfaces [ 49 ]. Consequently, the risk of fracture and detachment may be greater when RNC is used in an implant, though, it showed relatively high fracture resistance in teeth.…”

The Impact of Increase in the Vertical Dimension of Occlusion on Nociception in Rats - A Preliminary Report

“…The VDO raising protocols were performed according to the following algorithm: on a day 1, the animals were anesthetized (combination of ketamine 10 mg/kg and xylazine 5 mg/kg, i.p., Figure 1A) and a two-phase impression was taken with addition silicones (Hydrorise putty and light body, Zhermack, Italy). On a day 3, the cementing process for both incisors and inside crowns preparation and cleaning was performed, and then cementing zirconium crowns (Figure 1B) on both maxillary incisors were applied (Multilink Automix, Ivoclar, Vivadent, Liechtenstein), according to previously described procedure (21), also following anaesthetic procedure. The zirconium crowns were manufactured using CAD-CAM technology based on the working model, to achieve the VDO alteration for 0.6, 0.9 and 1.2 mm.…”