ABSTRACT
BACKGROUND: Zirconia ceramic was considered as one of the optimal materials in prosthodontics and widely used in daily clinical treatment for its features, such as aesthetic properties, biocompatibility and corrosion resistance. Ideal bond strength and durability are necessary for the restoration to achieve satisfied clinical performance. OBJECTIVE: To systematically review zirconia and common zirconia bonding agents, the physical and chemical properties of zirconia ceramics, the clinical operating process standard, the common zirconia bonding agents and their bonding performance. METHODS: We searched the articles from March 2005 to March 2020 in PubMed, CNKI, Wanfang databases with the key words of “zirconia; surface treatment; universal adhesive; self-adhesive resin cement; bonding strength” in Chinese and English. After screening according to inclusion and exclusion criteria, the final 36 included articles were summarized. RESULTS AND CONCLUSION: Zirconia has excellent physical and chemical properties with hydrophobic surface, so it is difficult to form a proper bonding surface with the substrate. At present, the combination of physical sand blasting and chemical reaction is the most common treatment. The sand blasting can effectively increase the reaction area. In the aspect of chemical bonding, the bond strength of the self-adhesive resin cement can be significantly improved by both the universal adhesive and zirconia primer after 24 hours of water storage; however, the durability of universal adhesive is better than that of zirconia primer. As common sense, 37% phosphoric acid is daily used on tooth surface before bonding procedure, which can prohibit chemical reaction to zirconia. Sand blasting was considered as one of the most practical way to physically increase the surface for 10-MDP contained primers or universal adhesives chemically reacted with zirconia.
ABSTRACT
OBJECTIVES: The aim of this study is to compare the shear bond strengths of ceramic brackets bonded to zirconia surfaces using different zirconia primers and universal adhesive. MATERIALS AND METHODS: Fifty zirconia blocks (15 × 15 × 10 mm, Zpex, Tosoh Corporation) were polished with 1,000 grit sand paper and air-abraded with 50 µm Al2O3 for 10 seconds (40 psi). They were divided into 5 groups: control (CO), Metal/Zirconia primer (MZ, Ivoclar Vivadent), Z-PRIME Plus (ZP, Bisco), Zirconia Liner (ZL, Sun Medical), and Scotchbond Universal adhesive (SU, 3M ESPE). Transbond XT Primer (used for CO, MZ, ZP, and ZL) and Transbond XT Paste was used for bracket bonding (Gemini clear ceramic brackets, 3M Unitek). After 24 hours at 37°C storage, specimens underwent 2,000 thermocycles, and then, shear bond strengths were measured (1 mm/min). An adhesive remnant index (ARI) score was calculated. The data were analyzed using one-way analysis of variance and the Bonferroni test (p = 0.05). RESULTS: Surface treatment with primers resulted in increased shear bond strength. The SU group showed the highest shear bond strength followed by the ZP, ZL, MZ, and CO groups, in that order. The median ARI scores were as follows: CO = 0, MZ = 0, ZP = 0, ZL = 0, and SU = 3 (p < 0.05). CONCLUSIONS: Within this experiment, zirconia primer can increase the shear bond strength of bracket bonding. The highest shear bond strength is observed in SU group, even when no primer is used.
Subject(s)
Adhesives , Ceramics , Orthodontic Brackets , Solar SystemABSTRACT
OBJECTIVE: The aim of this study was to compare the shear bond strength (SBS) of orthodontic brackets bonded to zirconia surfaces using three different zirconia primers and one silane primer, and subjected to thermocycling. METHODS: We designed 10 experimental groups following the surface treatment and thermocycling. The surface was treated with one of the following method: no-primer (NP), Porcelain Conditioner (PC), Z-PRIME Plus (ZP), Monobond Plus (MP) and Zirconia Liner Premium (ZL) (n=20). Then each group was subdivided to non-thermocycled and thermocycled groups (NPT, PC, ZPT, MPT, ZLT) (n=10). Orthodontic brackets were bonded to the specimens using Transbond(TM) XT Paste and light cured for 15 s at 1,100 mW/cm2. The SBS was measured at a 1 mm/min crosshead speed. The failure mode was assessed by examination with a stereomicroscope and the amount of bonding resin remaining on the zirconia surface was scored using the modified adhesive remnant index (ARI). RESULTS: The SBS of all experimental groups decreased after thermocycling. Before thermocycling, the SBS was ZL, ZP > or = MP > or = PC > NP but after thermocycling, the SBS was ZLT > or = MPT > or = ZPT > PCT = NPT (p > 0.05). For the ARI score, both of the groups lacking primer (NP and NPT) displayed adhesive failure modes, but the groups with zirconia primers (ZP, ZPT, MP, MPT, ZL, and ZLT) were associated with mixed failure modes. CONCLUSIONS: Surface treatment with a zirconia primer increases the SBS relative to no-primer or silane primer application between orthodontic brackets and zirconia prostheses.