ABSTRACT
Objective: the study is aimed to evaluate the effect of different surface treatment methods on shear bond strength between composite repair system and both of zirconia core and veneering porcelain and analyze the mode of failure between composite repair and ceramic surface. Material and methods: 40 Ceramic discs were fabricated with diameter of 7mm and 3mm thickness and divided according to material into two groups, Zirconia core discs (n = 20) and veneering porcelain discs (n = 20). Specimens were thermocycled and then each group was subdivided according to surface treatment method into 4 equal sub groups (n = 5) ,control subgroup I air abrasion, subgroup II Cojet, subgroup III laser, subgroup IV combination of air abrasion and laser surface treatment. Composite blocks were built up and polymerized on the surface of the specimens and shear bond strength of composite to each specimen was tested using a universal testing machine and mode of failure was evaluated using stereomicroscope. Results: Regardless of ceramic type; there was a statistically significant difference between surface treatments. Cojet recorded the highest mean shear bond strength. Laser showed the highest prevalence of adhesive failure. Porcelain + Cojet showed the highest prevalence of cohesive failure. Conclusion: Cojet surface treatment provided superior shear bond strength regardless of the ceramic type whether zirconia or porcelain. Porcelain provided superior shear bond strength values in comparison to zirconia regardless of the surface treatment method tested. Porcelain showed higher percentage of cohesive failure that while the mode of failure in zirconia was most commonly adhesive. (AU)
Objetivo: O objetivo deste estudo foi avaliar o efeito de diferentes métodos de tratamento de superfície na resistência ao cisalhamento de reparos de resina composta e núcleos de zircônia ou cobertura de porcelana, e analisar o modo de falha entre o reparo e a superfície cerâmica. Material e métodos: 40 discos de cerâmica foram fabricados com diâmetro de 7 mm e 3 mm de espessura e divididos de acordo com o material em dois grupos, discos de zircônia (n = 20) e discos de porcelana (n = 20). As amostras foram termocicladas e, em seguida, cada grupo foi subdividido de acordo com o método de tratamento de superfície em 4 subgrupos iguais (n = 5), subgrupo I :controle (abrasão a ar); subgrupo II: Cojet; subgrupo III: laser; subgrupo IV: combinação de abrasão a ar e tratamento de superfície a laser. Blocos de resina composta foram construídos e polimerizados na superfície das amostras e a resistência ao cisalhamento do compósito para cada amostra foi testada usando uma máquina de teste universal e o modo de falha foi avaliado usando o estereomicroscópio. Resultados: Independentemente do tipo de cerâmica houve diferença estatisticamente significante entre os tratamentos de superfície. Cojet registrou a maior força média de união ao cisalhamento. O laser mostrou a maior prevalência de falha adesiva. Porcelana + Cojet apresentou a maior prevalência de falha coesiva. Conclusão: O tratamento superficial com Cojet proporcionou resistência superior ao cisalhamento, independentemente do tipo de cerâmica, seja zircônia ou porcelana. A porcelana forneceu valores superiores de resistência ao cisalhamento em comparação com a zircônia, independentemente do método de tratamento de superfície testado. A porcelana apresentou maior porcentagem de falha coesiva que enquanto o modo de falha na zircônia era mais comumente adesivo. (AU)
Subject(s)
Shear Strength , Dental Porcelain , LasersABSTRACT
PURPOSE: The purpose of this study was to evaluate the bond strength of composite resin on the fracture surface of metal-ceramic depending on the repair systems and surface roughening methods. MATERIALS AND METHODS: A total of 30 disk specimens were fabricated, 15 of each were made from feldspathic porcelain and nickel-chromium base metal alloy. Each substrate was divided into three groups according to the repair method: a) application of repair system I (Intraoral Repair Kit) with diamond bur roughening (Group DP and DM), b) application of repair system I with airborne-particle abrasion (Group SP and SM), and c) application of repair system II (CoJet Intraoral Repair System, Group CP and CM). All specimens were thermocycled, and the shear bond strength was measured. The data were analyzed using the Kruskal-Wallis analysis and the Mann-Whitney test with a significance level of 0.05. RESULTS: For the porcelain specimens, group SP showed the highest shear bond strength (25.85 +/- 3.51 MPa) and group DP and CP were not significantly different. In metal specimens, group CM showed superior values of bond strength (13.81 +/- 3.45 MPa) compared to groups DM or SM. CONCLUSION: Airborne-particle abrasion and application of repair system I can be recommended in the case of a fracture localized to the porcelain. If the fracture extends to metal surface, the repair system II is worthy of consideration.
Subject(s)
Alloys , Dental Instruments , Dental PorcelainABSTRACT
PURPOSE: This in vitro study evaluated shear bond strengths of surface treatment porcelains with four porcelain repair systems simulating intraoral bonding of composite resin to feldspathic porcelain or pressable porcelain. MATERIAL AND METHODS: Eighty Porcelain disks were prepared. Group A: forty disk specimens were fabricated with Feldspathic Porcelain(Omega(R)900, Vident, Menlo Park, CA, USA). Group B: forty disk specimens were fabricated with Pressable Porcelain(IPS Empress 2 ingot, Ivoclar-Vivadent, Schaan, Liechtenstein, Germany). Each groups was divided into 4 subgroups and composite resin cylinders were bonded to specimen with one of the following four systems: Clearfil Porcelain Bond(L. Morita, Tustin, CA, USA), Ulradent Porcelain Etch.(Ultradent, Salt Lake City, UT, USA), Porcelain Liner-M(Sun Medical Co., Kyoto, Japan), Cimara Kit(Voco, Germany). After surface conditioning with one of the four porcelain repair systems, substrate surfaces of the specimen were examined microscopically(SEM). Shear bond strengths of specimens for each subgroup were determined with a universal testing machine (5mm/min crosshead speed) after storing them in distilled water at 37+/-1 degrees C for 24 hours. Stress at failure was measured in MPa, and mode of failure was recorded. Differences among four repair systems were analyzed with two way ANOVA and Duncan test at the 95% significance level. RESULTS: In the scanning electron photomicrograph of the treated porcelain surface, hydrofluoric acid etched group appeared the highest roughness. The shear bond strength of the phosphoric acid etched group was not significantly(p>0.05) different between feldspathic porcelain and pressable porcelain. But in no treatment and roughened with a bur group, the shear bond strength of the feldspathic porcelain was significantly higher than that of the pressable porcelain. In hydrofluoric acid etched group, the shear bond strength of the pressable porcelain was significantly higher(p0.05). However in the other groups, there were significant differences in shear bond strengths between feldspathic porcelain and pressable porcelain(p<0.05).
Subject(s)
Dental Porcelain , Hydrofluoric Acid , Lakes , Liechtenstein , WaterABSTRACT
STATEMENT OF PROBLEM: Dental ceramics exhibit excellent esthetic property, compressive strength, chemical durability, biocompatibility and translucency. However, it suffers from inherent brittle fractures. Various techniques and materials for intraoral porcelain repair has been suggested. PURPOSE: This study is to compare the tensile bond strength of four commonly used porcelain repair systems (Vivadent, Bisco, Ultradent, Voco) and to insure the best system for the clinical application to the fractured porcelain. MATERIALS AND METHODS: A total of fifty specimens were fabricated. Specimens were stored in 37degrees C distilled water for 7 days and thermocycling was performed(1000 cycles), and subjected to a tensile force parallel to the repair resin and porcelain interface by use of an Universal Testing Machine. RESULT: 1. Voco showed the highest tensile bond strength. In decreasing order, the tensile bond strength of the other materials was as follows : Ultradent, Bisco, Vivadent. 2. There was a statistically significant difference between the porcelain repair systems(Voco, Ultradent > Bisco, Vivadent) (p<0.05). 3. SEM examination of prepared porcelain surfaces revealed that the surface treated with Voco showed brittle fracture. However, Ultradent, Bisco and Vivadent showed ductile fracture. 4. All specimens treated with four porcelain repair systems showed adhesive failure between porcelain and composite resin.
Subject(s)
Adhesives , Ceramics , Compressive Strength , Dental Porcelain , WaterABSTRACT
STATEMENT OF PROBLEM: Porcelain restorations are widely used in restorative dentistry with a high degree of general success. However, porcelain is brittle and may fracture intraorally. Sometimes a repair may be attempted using composite resin and bonding system available. Color stability of porcelain repair resins affects esthetics and prognosis of prosthesis, so that provides important criteria for the choice of porcelain repair resins. PURPOSE: The purpose of this study was to investigate the color stability of composite resins used widely as porcelain repair system. MATERIALS AND METHOD: Composite resins used for this study were Carisma(Kulzer, Germany), Tetric ceram(Ivoclar, Liechtenstein), Filtek Z250(3M, USA), and Arabesk Top(VOCO, Germany). Thirty disc-shaped specimens(10x2mm) were fabricated from each composite resin. Color changes of specimens after treatment using thermocycling system(KD-TCS30, Kwang-duk F.A. Korea) and after immersion in methylene blue(0.05% by Wt) were measured with colorimeter(Model Tc- 6Fx, Tokyo Denshoku Co.) and obtained data were analyzed. RESULTS AND CONCLUSION: The results obtained from this study were as follows. 1. The color change of Filtek Z250 was lesser than those of Tetric ceram and Arabesk Top after thermocycling (12000 times). 2. All of the composite resins in this study showed increase of color change according to increase of thermocycling frequency. 3. After treatment with methylene blue, the color change of Arabesk Top was greater than those of Carisma and Tetric ceram, and Tetric ceram was more stable than others.