However, economic factors, occlusal disorders, lack of adequate bone support or excessive removal of healthy dental structure are some of the limiting factors in the indication of some the options.Ĭonventionally, metal alloy has been used as the material for the framework either via porcelain-fused-metal (PFM) or resin bonded (Maryland type) fixed partial denture. A number of restorative options have been recommended in such cl inical situations: implants, fixed metal ceramic or all ceramic prostheses and resin bonded fixed partial dentures (FPDs). With regard to the cohesive strength (σc), ZP1 presented the highest values.Ĭonclusion: It can be concluded that the presence of more than one porcelain layer decreases its cohesive strength and its bonding strength to zirconia.Replacing a single missing tooth in the anterior area lost due to dental caries or trauma represents a challenge for the clinician. The predominant failure mode for the bonded specimens was cohesive. Results: The ZP1 group presented the highest values for σa data, compared with other groups, which were statistically similar. The data were analyzed by Kruskal-Wallis and Dunns tests (α = 0.05) or ANOVA and Tukeys test (α = 0.05), according to their distribution parameters. The failure mode was classified as cohesive (used to calculate the cohesive strength, σc) or adhesive (bond strength, σa). We calculated strength (σ, in MPa) by dividing the fracture load (N) by the fractured area (mm2).

The specimens were cut into 1 mm2 microbars and tested under tension in a universal testing machine (0.5 mm/min). All study specimens were sintered three times. Ten specimens with V9 were prepared following the same protocols of groups 1 (P1) and 3 (P3).

The feldspathic porcelain (V9) was applied to the zirconia in different numbers of layers up to 1 cm total thickness (n = 10): ZP1 - one layer ZP2 - two layers ZP3 - three layers. Materials and Methods: Y-TZP blocks were cut into 1 cm3 specimens (n = 30). Purpose: To evaluate the influence of the number of porcelain layers on its cohesive strength and on bonding to zirconia.

Macedo, Vanessa Cruz / Anami, Lilian Costa / de Melo, Renata Marques / Bottino, Marco Antonio / Valandro, Luiz Felipe Effect of the Layering Technique on Bond Strength and Cohesive Resistance of a Porcelain-Zirconia System

Porcelain layering technique