Objective: The objective of this study was to evaluate the clinical results of 323 porcelain laminate veneers over a period of 3 to 11 years. Material and Methods: This study included 70 patients, aged between 18 and 74 years. Of the 323 total veneers, 124 were of a simple design and 199 were of a functional design. The condition of the soft tissues and hygiene, in addition to the condition of the abutment teeth, the restorations and patient satisfaction were all clinically examined. In carrying out the statistical analysis, a descriptive approach was taken in analyzing the data. The Kaplan Meier method was used for statistically analyzing the survival rates of the porcelain laminate veneers. Results: Analysis of the soft tissue revealed marginal recession in 7.7% of the cases, and in 21.6% of the cases, bleeding was detected on probing. Analysis of the condition of the abutment teeth revealed secondary caries and hypersensitivity in 3.1% of the cases, and changes in pulp vitality were observed in 2.8% of the cases. In studying the condition of the restorations, marginal integrity was observed to be excellent in 98% of the cases, slight marginal pigmentation was present in 39.3% of the cases, fractures were present in 4% of the cases and decementation in 9% of the cases. The degree of patient satisfaction was considered to be excellent in 97.1% of the cases. Conclusions: Porcelain laminate veneers are a predicable treatment option that offer excellent results.

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Objectives: This study aims to determine whether bruxism and the use of occlusal splints affect the survival of porcelain laminate veneers in patients treated with this technique. Material and Methods: Restorations were made in 70 patients, including 30 patients with some type of parafunctional habit. A total of 323 veneers were placed, 170 in patients with bruxism activity, and the remaining 153 in patients without it. A clinical examination determined the presence or absence of ceramic failure (cracks, fractures and debonding) of the restorations; these incidents were analyzed for association with bruxism and the use of splints. Results: Analysis of the ceramic failures showed that of the 13 fractures and 29 debonding that were present in our study, 8 fractures and 22 debonding were related to the presence of bruxism. Conclusions: Porcelain laminate veneers are a predictable treatment option that provides excellent results, recognizing a higher risk of failure in patients with bruxism activity. The use of occlusal splints reduces the risk of fractures. Key words:Veneer, fracture, debonding, bruxism, occlusal splint.

Objectives: The aim of this study was to evaluate bond strengths of zirconium-oxide (zirconia) ceramic and a selection of different composite resin cements. Study Design: 130 Lava TM cylinders were fabricated. The cylinders were sandblasted with 80 µm aluminium oxide or silica coated with CoJet Sand. Silane, and bonding agent and/or Clearfil Ceramic Primer were applied. One hundred thirty composite cement cylinders, comprising two dual-polymerizing (Variolink II and Panavia F) and two autopolymerizing (Rely X and Multilink) resins were bonded to the ceramic samples. A shear test was conducted, followed by an optical microscopy study to identify the location and type of failure, an electron microscopy study (SEM and TEM) and statistical analysis using the Kruskal-Wallis test for more than two independent samples and Mann-Whitney for two independent samples. Given the large number of combinations, Bonferroni correction was applied (α=0.001). Results: Dual-polymerizing cements provided better adhesion values (11.7 MPa) than the autopolymerizing (7.47 MPa) (p-value M-W<0.001). The worst techniques were Lava TM + sandblasting + Silane + Rely X; Lava TM + sandblasting + Silane + Multilink and Lava TM + CoJet + silane + Multilink. Adhesive failure (separation of cement and ceramic) was produced at a lesser force than cohesive failure (fracture of cement) (p-value M-W<0.001). Electron microscopy confirmed that the surface treatments modified the zirconium-oxide ceramic, creating a more rough and retentive surface, thus providing an improved micromechanical interlocking between the cement and the ceramic. Key words:Shear bond strength, silica coating, surface treatment, zirconia ceramics, phosphate monomer.

To evaluate bond strengths of different resin cements to two aluminum oxide-based ceramics. Methods: One hundred ten ceramic cylinders were produced and given four different surface treatments. Resin cement cylinders were then bonded to the ceramic cylinders using different resin cements and the bond strength was determined by shear testing to the breaking point. We were thus able to obtain results for the different combinations of porcelain, surface treatments and cements. All data was analyzed using the Kruskal-Wallis test for more than two independent samples and the Bonferroni correction applied (a=0.01). An optical microscopy study was carried out to analyze the type of failure, and an electronic microscopy examination was carried out in order to evaluate the changes produced in the ceramic by the different surface treatments. Results: The best values corresponded to the control group, composed of silicate ceramics combined with Variolink II resin cement. In-Ceram Alumina showed no significant differences with respect to the type of cement applied. Procera AllCeram obtained the best values when silica coated using the CoJet System and applying Variolink II, or when sandblasted and applying Clearfil SE Bond + Porcelain Bond Activator and Panavia F cement. Significance: Surface treatment modifies the ceramic surface and influences the bond strength, as does the type of cement used. Silica coating is recommended to improve adhesion to Procera AllCeram, applying Variolink II, or sandblasting plus resin cement containing MDP (Panavia F).