Bond strengths of various resin cements to different ceramics

Abstract This study evaluates the shear bond strength (SBS) of various resin cements to different ceramics. Composite resin cylinders of Z100 were fabricated and cemented to disks of feldspathic ceramic (Creation), leucite-reinforced feldspathic ceramic (Empress I), and densely sintered aluminum oxide ceramic (Procera AllCeram) using five resin cements: Panavia F (PAN), RelyX ARC (ARC), RelyX Unicem (RXU), RelyX Veneer, and Variolink II. SBS was measured after three days of water storage (baseline) and after artificial aging (180 days of water storage along with 12,000 thermal cycles). Failure mode of fractured specimens also was evaluated. Data were analyzed with Kruskal-Wallis and Mann-Whitney tests (α=0.05). RXU showed 1) the lowest baseline median SBS to feldspathic ceramic, which was not statistically different from PAN; 2) the lowest median baseline SBS to leucite-reinforced feldspathic and densely sintered aluminum-oxide ceramics. All cements performed similarly after aging, except for ARC (median 0.0 MPa) and PAN (median 16.2 MPa) in the densely sintered aluminum-oxide ceramic group. Resin cements perform differently when bonded to different ceramic substrates. While all test resin cements worked similarly in the long-term to feldspathic and leucite-reinforced feldspathic ceramics, only the MDP-containing resin cement provided durable bonds to densely sintered aluminum-oxide ceramic.

One-Year Water Sorption and Solubility of All-in-One Adhesives

The aim of this study was to evaluate the water sorption and solubility of different adhesives. Adper Easy Bond, Adper Single Bond Plus, Bond Force, Clearfil SE Bond (bonding resin only), and Xeno IV were the materials evaluated. Ten disks of each adhesive were made in Teflon molds and evaporation of any volatile components was allowed. The disks were weighed daily in an analytical balance until a constant mass was obtained (m1). Disks were then immersed in water for 12 months when their wet weight was recorded (m2). The disks were again weighed daily until a constant mass was obtained and the final weight recorded (m3). Water sorption and solubility (percentages) were calculated using the recorded mass values. Kruskal-Wallis tests were used to compare the average water sorption and solubility among the different adhesives. Mann-Whitney tests with a Bonferroni correction were used to determine the pairwise differences between adhesives in water sorption and solubility. The level of significance was set at 0.05. Water sorption and solubility were significantly different among the groups (p<0.05). Pairwise comparisons showed no significant differences (p>0.05) between Adper Single Bond Plus and Bond Force, or between Clearfil SE Bond and Xeno IV in either water sorption or solubility. Xeno IV did not differ from Adper Easy Bond in water sorption (p>0.05). Water sorption and solubility of all-in-one adhesives increased with time, and the rates of increase were composition-dependent. The results suggest that monomers other than HEMA contribute to water sorption and solubility of adhesive systems from different categories.

O objetivo deste estudo foi avaliar a absorção de água e a solubilidade de diferentes sistemas adesivos: Adper Easy Bond, Adper Single Bond Plus, Bond Force, Clearfil SE Bond (apenas a resina adesiva) e Xeno IV. Foram fabricados 10 discos de cada material em moldes de Teflon e foi permitida a evaporação de todos os componentes voláteis. Os discos foram pesados diariamente em balança analítica até atingir massa seca constante (m1). Após esta mensuração, os discos foram imersos em água por 12 meses e seu peso úmido foi anotado (m2). Os discos foram novamente pesados diariamente até obter-se massa constante (m3). As percentagens de absorção de água e solubilidade foram calculadas utilizando os valores de massa registrados. A comparação das médias de absorção de água e solubilidade entre os diversos adesivos foi feita com o teste Kruskal-Wallis. As diferenças de absorção de água e solubilidade entre os pares de adesivos foram determinadas pelo testes Mann-Whitney com correção de Bonferroni. O nível de significância adotado foi de 0,05. Absorção de água e solubilidade apresentaram diferenças estatisticamente significantes entre os grupos (p<0,05). As comparações pareadas dos adesivos não mostraram diferenças significantes (p>0,05) entre Adper Single Bond Plus e Bond Force nem entre Clearfil SE Bond e Xeno IV para absorção de água e solubilidade. Xeno IV apresentou diferença significante do Adper Easy Bond quanto à absorção de água (p>0,05). A absorção de água e solubilidade dos adesivos “all-in-one” aumentaram com o tempo e as taxas de aumento mostraram-se dependentes da composição do material. Os resultados sugerem que outros monômeros além do HEMA contribuem para a absorção de água e solubilidade dos diversos sistemas de adesivos.