Shear bond strengths of composite resin to porcelains among porcelain repair systems / 대한치과보철학회지

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).

Tensile bond strength of four porcelain repair systems / 대한치과보철학회지

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.