A comparison of bond strength of layered veneering porcelains to zirconia and metal

Effect of cooling rate on shear bond strength of veneering porcelain to a zirconia ceramic material

“…Table 1 Materials investigated in the present study Veneering porcelain slurry was placed on the veneering area and condensed with ultrasonic agitation using the Ceracon II (Shofu Inc.). Firing was performed in a porcelain furnace (Single Mat, Shofu Inc.), after which the porcelain slurry was layered on the specimens with a specially designed polytetrafluoroethylene (PTFE) split mold (K826, Tokyogiken Inc., Tokyo, Japan) and ultrasonically agitated using the Ceracon II (Shofu Inc.) (14). Then, the slurry was blotted with tissue to draw excess water.…”

“…A P value of less than 0.05 was considered to indicate statistical significance. Some of the data have been previously published (14).…”

A study of compressive strength between zirconia framework and veneering ceramic as a function of thermal expansion coefficient using Shell–Nielsen test method

“…Although monolithic zirconia FDPs have become popular in recent years, in most cases zirconia frameworks are veneered to enhance the optical properties of the final restoration. The mechanical strength, stability of the framework, and the adhesion of the veneering ceramic (VC) to the framework are crucial factors for clinically successful performance and reliability of a veneered zirconia FDP [4,5].…”

“…Bond strength of a VC to zirconia is affected by many variables such as restoration geometry, framework design, surface finish, roughness and treatment, wettability of zirconia framework, phase transformation, structural defects yielding to flaw development, reactions at the framework-veneer interface, residual tensile stresses during the cooling process and Coefficient of Thermal Expansion (CTE) mismatch between framework and the VC [4][5][6][7]. Individual or the combined effects of all these variables could influence the framework-veneer bond strength and therefore the clinical success rate of FDPs made of such materials [4][5][6][7].…”

“…Commonly used SBS and MTBS tests often show cohesive failure patterns within the VC. Thus, the results do not represent the actual bond strength at the interface [5,26,27]. Each test setup plays an important role in determining the framework-veneer bond strength and has limitations in measuring the interfacial bond strength [1,2,6,7,12,24,28].…”