ABSTRACT
PURPOSE: The objective of this study was to evaluate the effect of thermocycling (TC), self-adhesive resin cements and surface conditioning on the microtensile bond strength (µTBS) between feldspathic ceramic blocks and resin cements. MATERIALS AND METHODS: Fifty-six feldspathic ceramic blocks (10 x 7 x 5 mm) (Vita Mark II) were divided into groups according to the factors "resin cement" (3 cements) and "surface conditioning" (no conditioning or conditioning [10% hydrofluoric acid etching for 5 min + silanization]) (n = 8): group 1: conditioning+Variolink II (control group); group 2: no conditioning+Biscem; group 3: no conditioning+RelyX U100; group 4: no conditioning+Maxcem Elite; group 5: conditioning+ Biscem; group 6: conditioning+RelyX U100; group 7: conditioning+Maxcem Elite. The ceramic-cement blocks were sectioned to produce non-trimmed bar specimens (adhered cross-sectional area: 1 ± 0.1 mm2), which were divided into two storage conditions: dry, µTBS immediately after cutting; TC (12,000x, 5°C/55°C). Statistical significance was determined using two-way ANOVA (7 strategies and 2 storage conditions) and the post-hoc Tukey test (p < 0.05). RESULTS: Resin cement and thermocycling affected the µTBS significantly (p = 0.001). In the dry condition, group 5 (18 ± 6.5 MPa) presented the lowest values of µTBS when compared to the other groups. TC decreased the mean µTBS values significantly (p < 0.05) for all resin cements tested (9.7 ± 2.3 to 22.1 ± 6.3 MPa), except for the resin cement RelyX U100 (22.1 ± 6.3 MPa). In groups 3 and 4, it was not possible to measure µTBS, since these groups had 100% pre-test failures during sectioning. Moreover, the same occurred in group 2 after TC, where 100% failure was observed during thermocycling (spontaneous failures). CONCLUSION: Hydrofluoric acid etching and silanization of the feldspathic ceramic surface are essential for bonding self-adhesive resin cement to a feldspathic ceramic, regardless of the resin cement used. Non-etched ceramic is not recommended.
Subject(s)
Acid Etching, Dental , Dental Bonding , Dental Porcelain , Resin Cements , Acid Etching, Dental/methods , Aluminum Silicates , Analysis of Variance , Dental Stress Analysis , Hot Temperature , Hydrofluoric Acid , Materials Testing , Potassium Compounds , Silanes , Statistics, Nonparametric , Surface Properties , Tensile StrengthABSTRACT
The aim of the present study was to evaluate the effect of thermocycling (TC) on the microtensile bond strength (microTBS) of two luting agents to feldspathic ceramic and to measure their film thickness (FT). For the microTBS test, sixteen blocks (6.4 x 6.4 x 4.8 mm) were fabricated using a feldspathic ceramic, etched with 10% hydrofluoric acid, rinsed and treated with the silane agent. The ceramic blocks were divided into two groups (n= 8): Gr1: dual-cured resin cement and Gr2: flowable resin. The luting agents were applied on the treated surfaces. Microsticks (1 +/-0. 1mm2) were prepared and stored under two conditions: dry, specimens immediately submitted to the microTBS test, and TC (6,000 cycles; 5 degrees C-55 degrees C). The microTBS was evaluated using a universal testing machine (1 mm/min). The microTBS data (MPa) were submitted to two-way ANOVA and Tukey' test (5%). For the FT test (ISO 4049), 0.05 ml of each luting agent (n=8) was pressed between two Mylar-covered glass plates (150 N) for 180 seconds and light polymerized. FT was measured using a digital paquimeter (Model 727-2001). The data (mm) were submitted to one-way ANOVA. The luting cement did not influence the microTBS results (p= 0.4467). Higher microtensile bond values were found after TC (20.5 +/- 8.6 MPa) compared to the dry condition (13.9 +/- 4. 7MPa), for both luting agents. The luting agents presented similar film thicknesses: Gr1- 0.052 +/- 0.016 mm; Gr2-0.041 +/- 0.003 mm. The luting agents presented similar film thickness and microTBS values, in dry and TC conditions and TC increased the bond strength regardless of the luting agent.
Subject(s)
Ceramics , Dental Bonding , Dental Cements , Materials Testing , TemperatureABSTRACT
Limitações anatômicas quantitativas e qualitativas do tecido ósseo, bem como reabsorçõesdiversas, limitam a realição dos procedimentos cirúrgicosna implantodontia. O formato do rebordo reabsorvido com conseqüente instalação de implantes com inclinações inadequadas, muitas vezes, resulta no comprometimento doperfil de emergência do transmucoso interferindo na resolução estética e biomecânica da prótese. Além disso , o alto grau de exig~encia estética dos pacientes e profissionais, o tempo, a morbilidade e o custo do tratamanto passaram a ter utualmente um grau de relevância muito maior. Assim sendo, a busca para as soluções de alta qualidade em espaço de tempo cada vez menos tornou-se fundamental. Cirurgias reconstrutivas como o enxerto ósseo t~em sido indicadas como alternativa para compensar essas limitações. Embasada na literatura científica a abordagem cirúrgica simultânea de reconstrução de áreas com defeitos ósseos e a colocaçãode implantes tornou-se uma alternativa terapêutica eficaz quando utilizada de forma criteriosa. esse estudo tem como objetivo relatar uma técnica cirúrgica alternativa de colocação de implante e a correção simultânea de uma área com defeito ósseo.
