Preheated acid associated with silane and electric current in the adhesion of the resin cement to ceramic

Abstract This study verified the effect of the combination of preheated hydrofluoric acid/silane/electric current in the adhesion of the resin cement to ceramic. IPS E.max Press ceramic discs embedded in PVC rigid tubes were divided into four groups associating preheated hydrofluoric acid and silane applied with electrical current (n=10): Ha+S (Heated acid + silane); Ha+S+Ec (Heated acid + silane + electrical current); A+S (Acid + silane) and A+S+Ec (Acid + silano + electrical current). Resin cement/ceramic samples were stored in water at 37°C for 24h. After storage, they were submitted to the microshear test, fracture analysis, and contact angle at 24h or after thermocycling (10,000 cycles/5-55ºC). Bond strength data were evaluated by two-way ANOVA. For comparison between evaluation times (24h or thermocycling) was applied unpaired t-test. A significance post-hoc test of p=0.05 was assumed for analyses and graphs (GraphPad Prism 9.0 software). At 24h, the microshear strength showed similar values between Ha+S, Ha+S+Ec, and A+S+Ec groups, while A+S showed the lowest value with a statistical difference. After thermocycling, Ha+S and Ha+S+Ec were similar, as well as A+S and A+S+Ec. There was a significant difference in all groups comparing 24h (highest value) with after thermocycling (lowest value). Adhesive fracture was predominant in all groups and evaluation times. Ha+S and A+S groups showed higher contact angle values compared to the Ha+S+Ec and A+S+Ec with lower values. In conclusion, the association of preheated hydrofluoric acid/silane applied or not with electric current promoted different microshear strength values, fracture types, and contact angles in the resin cement/ceramic bond.

Resumo Este estudo verificou o efeito da combinação ácido fluorídrico pré-aquecido/silano/corrente elétrica na adesão do cimento resinoso à cerâmica. Os discos cerâmicos IPS E.max Press embutidos em tubos rígidos de PVC foram separados em quatro grupos associando ácido fluorídrico pré-aquecido e silano aplicado com corrente elétrica (n=10): Ha+S (ácido aquecido + silano); Ha+S+Ec (Ácido aquecido + silano + corrente elétrica); A+S (Ácido + silano) e A+S+EC (Ácido + silano + corrente elétrica). Amostras de cimento resinoso/cerâmica foram armazenadas em água a 37°C por 24 horas. Após o armazenamento foram submetidas ao ensaio de micro cisalhamento, análise de fratura e ângulo de contato no período de 24 horas ou após termociclagem (10.000 ciclos/5-55ºC). Os dados de resistência de união foram avaliados por ANOVA dois fatores. Para comparação entre os tempos de avaliação (24 horas ou termociclagem) foi aplicado o teste t não pareado. Foi assumida significância de 5% para análises e gráficos (software GraphPad Prism 9.0). Em 24 horas, a resistência ao micro cisalhamento apresentou valores similares entre os grupos Ha+S, Ha+S+Ec e A+S+Ec, enquanto A+S apresentou menor valor com diferença estatística. Após a termociclagem, Ha+S e Ha+S+Ec foram similares, assim como A+S e A+S+Ec. Houve diferença significativa em todos os grupos comparando 24 horas (maior valor) com após termociclagem (menor valor). A fratura adesiva foi predominante em todos os grupos e tempos de avaliação. Os grupos Ha+S e A+S apresentaram maiores valores de ângulos de contato comparados aos grupos Ha+S+Ec e A+S+Ec com valores menores. Em conclusão, a associação ácido fluorídrico pré-aquecido/silano aplicado com corrente elétrica promoveu diferentes valores de resistência ao micro cisalhamento, tipos de fratura e ângulos de contato na adesão do cimento resinoso à cerâmica.

Evaluation the stress distribution in root canals by 3D finite element analysis after the materials used in reattaching the vertically root fractured fragments

Abstract The aim was to evaluate the effect of stress distribution on vertical, horizontal, and oblique forces on the tooth model after reattaching the fragments of the maxillary incisor with vertical root fracture (VRF) using different materials, by 3D finite element analysis (FEA). Tooth with a root canal, spongious, and cortical bone models were designed. VRF was modeled on a tooth with 4 different re-attachment models: Group 1: dual-cure cement (DC)+fiber reinforced composite (FRC), Group 2: DC+polyethylene fiber, Group 3: DC+glass fiber, and Group 4:DC. 100 N force was applied in 3 different directions. Maximum principal stresses (σmax) of dentin, and re-attachment materials were evaluated on colored images. The highest σmax values ​​were on the repair materials under vertical forces for Groups 1 and 4, respectively; Groups 2 and 3 showed similarity. The highest σmax values in repair materials under horizontal and oblique forces were observed in Group 3 however the lowest σmax values in repair materials under oblique and horizontal forces were observed in Group 1. The stress values ​​on repair materials gradually increased respectively starting from horizontal to vertical. As the elasticity modulus of the repair materials increased, the stress values ​​on root dentin increased. Through all force directions, except vertical forces, lower stress values were observed with FRC. The fracture resistance was bigger when using solely FRC or dual-cure resin cement in comparison to fiber-supported designs. Adding polyethylene fiber to re-restorations decreased stress values ​​compared to glass fiber addition. Therefore, when adding fibers, polyethylene fiber will be advantageous.

Resumo O objetivo foi avaliar o efeito da distribuição de estresse nas forças verticais, horizontais e oblíquas no modelo de dente após a recolocação dos fragmentos do incisivo superior com fratura radicular vertical (FRV) usando diferentes materiais, por meio da análise de elementos finitos (FEA) em 3D. Métodos: Foram projetados modelos de dentes com canal radicular, osso esponjoso e cortical. A FRV foi modelada em um dente com 4 modelos diferentes de reataque, como Grupo 1: cimento de cura dupla (DC) + compósito reforçado com fibra (FRC), Grupo 2: DC + fibra de polietileno, Grupo 3: DC + fibra de vidro e Grupo 4: DC. Foi aplicada uma força de 100 N em 3 direções diferentes. As tensões principais máximas (σmax) da dentina e os materiais de recolocação foram avaliados em imagens coloridas. Resultados: Os valores mais altos de σmax foram registrados nos materiais de reparo sob forças verticais para os Grupos 1 e 4, respectivamente; os Grupos 2 e 3 apresentaram semelhança. Os valores mais altos de σmax nos materiais de reparo sob forças horizontais e oblíquas foram observados no Grupo 3; no entanto, os valores mais baixos de σmax nos materiais de reparo sob forças oblíquas e horizontais foram observados no Grupo 1. Os valores de tensão nos materiais de reparo aumentaram gradualmente, respectivamente, começando da holizontal para a vertical. À medida que o módulo de elasticidade dos materiais de reparo aumentava, os valores de tensão na dentina da raiz aumentavam. Em todas as direções de força, exceto nas forças verticais, foram observados valores de tensão mais baixos com o FRC. Conclusões: a resistência à fratura foi maior quando se utilizou apenas FRC ou cimento resinoso de cura dupla em comparação com os designs com suporte de fibra. A adição de fibra de polietileno às restaurações diminuiu os valores de tensão em comparação com a adição de fibra de vidro. Portanto, ao adicionar fibras, a fibra de polietileno será vantajosa.

Impact of Access Cavity Design on Fracture Resistance of Endodontically Treated Maxillary First Premolar: In Vitro

Abstract This study was designed to investigate the impact of access cavity designs on fracture resistance of endodontically treated maxillary first premolars. The study sample consisted of 72 intact maxillary first premolars, randomly divided into six groups (n = 12). A standardized proximal cavity preparation was prepared for all samples using standard bur. Groups I: control group with only standard proximal cavity and no endodontic access, group II: Truss access cavity, group III: Separated access to buccal and palatal canals without removal of dentine in between, group IV: Access to buccal and palatal canals with removal of dentine in between, group V: Traditional access cavity, group VI: Mesio-occlusal-distal cavity (MOD). For groups I and VI, only composite restoration was used to restore the proximal cavity, while for groups II- V, the access was prepared and endodontic treatment was performed on all teeth, then composite restoration was placed. The root canals were instrumented using nickel-titanium files, irrigated with sodium hypochlorite, and filled with AH plus sealer and gutta-percha using warm vertical condensation. All samples were then placed in an acrylic mold and underwent thermal aging for 10,000 cycles between 5 and 55°C. The samples were fixed in a universal testing machine with the long axis of the roots positioned at 20° to a load applied at a crosshead speed of 1 mm/min using a stainless steel semi-spherical indenter (Ø = 3 mm) until fracture occurred to determine the fracture resistance force in Newton. The normality test (Shapiro-Wilk) showed that data are normally distributed. Group II exhibited the highest mean fracture resistance, and group VI was the least likely to resist the fracture. No statistically significant differences between tested groups (p-value = 0.237). The MOD group showed a more unfavorable mode of fracture compared to other groups. No significant difference in fracture resistance between conservative and traditional access cavities. The missing marginal ridges, such as in MOD cavities played an important role in decreasing the fracture resistance of endodontically treated teeth.

Resumo O objetivo deste estudo foi investigar o impacto do design da cavidade de acesso na resistência à fratura de primeiros pré-molares superiores tratados endodonticamente. MÉTODOS: A amostra do estudo consistiu em 72 primeiros pré-molares superiores intactos, divididos aleatoriamente em seis grupos (n = 12). Um preparo padronizado da cavidade proximal foi realizado para todas as amostras usando broca padrão. Grupos I: grupo de controle com apenas cavidade proximal padrão e sem acesso endodôntico, grupo II: cavidade de acesso Truss, grupo III: acesso separado aos canais vestibular e palatino sem remoção de dentina entre eles, grupo IV: acesso aos canais vestibular e palatino com remoção de dentina entre eles, grupo V: cavidade de acesso tradicional, grupo VI: cavidade mesio-oclusal-distal (MOD). Para os grupos I e VI, apenas a restauração de compósito foi usada para restaurar a cavidade proximal. Já nos grupos II e V, o acesso foi preparado e o tratamento endodôntico foi realizado em todos os dentes e, em seguida, foi colocada a restauração de resina composta. Os canais radiculares foram instrumentados com limas de níquel-titânio, irrigados com hipoclorito de sódio e preenchidos com AH plus sealer e guta-percha usando condensação vertical quente. Todas as amostras foram então colocadas em molde de acrílico e submetidas a envelhecimento térmico por 10.000 ciclos entre 5 e 55°C. As amostras foram fixadas em uma máquina de teste universal com o eixo longo das raízes posicionado a 20° para uma carga aplicada a uma velocidade de cruzeta de 1 mm/min usando indentador semiesférico de aço inoxidável (Ø = 3 mm) até que ocorresse a fratura para determinar a força de resistência à fratura em Newton. RESULTADOS: O teste de normalidade (Shapiro-Wilk) mostrou que os dados são normalmente distribuídos. O grupo II apresentou a maior resistência média à fratura, e o grupo VI foi o menos propenso a resistir à fratura. Não houve diferenças estatisticamente significativas entre os grupos testados (p-valor = 0,237). O grupo MOD apresentou um modo de fratura mais desfavorável em comparação com os outros grupos. CONCLUSÕES: Não houve diferença significativa na resistência à fratura entre as cavidades de acesso conservador e tradicional. A ausência de cristas marginais, como nas cavidades MOD, desempenhou um papel importante na diminuição da resistência à fratura dos dentes tratados endodonticamente.

Characterization and biocompatibility analysis of different silanes coupling c(RGDfK) cyclic peptide on titanium surfaces / 口腔疾病防治

Objective@#To compare the efficiency and biocompatibility of four different silanes on immobilizing c(RGDfK) peptide on titanium surface.@*Methods @# After alkali-heat treatment (group OH), the titanium surface was treated with 3-aminopropyltriethoxysilane (APTES) (group OHAP), 3-chloropropyltriethoxysilane (CPTES) (group OHCP) (3-mercaptopropyltrimethoxysilane (MPTS) (group OHMPT) and 3-isobutyryloxy propyltrimethoxysilane(γ- MPS) (group OHMPS) to immobilize the c(RGDfK) cyclic peptide and constructa titanium-silane-c(RGDfK) coating. The NT group was the blank control group. The surface morphology and wettability of the coatings were detected using scanning electron microscopy and contact angle measurement. The elemental composition of the titanium surface was analyzed using X-ray photoelectron spectroscopy. After fluorescent staining with 4’,6-diamino-2-phenylindole (DAPI) and phalloidin, the adhesion of mouse preosteoblast MC3T3-E1 cells on the surface of the materials was observed using laser confocal microscopy. Cell counting kit-8 (CCK-8) and alkaline phosphatase (ALP) activity assays were used to evaluate the proliferation and osteogenic differentiation of MC3T3-E1 cells on the surface of the materials, respectively. @*Results @#Scanning electron microscope observation showed a spongy-like 3-dimensional network formed on the titanium surface after alkali-heat treatment with silane-c(RGDfK) coating adhesion. The wettability of each group was greatly improved compared to the untreated titanium surface. The element ratios of Si/Ti and amide-N/Ti in the OHMPS group were the highest. The OHAP group exhibited the best cell adhesion effect. The cell proliferation and ALP activity of the OHAP, OHMPT, and OHMPS groups were significantly higher than the control group (P <0.05); there was no statistical difference between the OHCP group and the control group.@*Conclusion @#MPTS, CPTES and γ-MPS covalently immobilized cyclic peptide c(RGDfK) on the titanium surface, which promoted adhesion, proliferation and osteogenic differentiation of MC3T3-E1 cells. Theγ-MPS conjugated C (RGDfK)cyclic peptide exhibited the best effect. MPTS, CPTES and γ-MPS coupled with c(RGDfK) cyclic peptides had similar biological properties.

Various surface treatment methods and resin cement type on the influence of bonding strength of zirconia ceramics / 中国组织工程研究

BACKGROUND: Due to the stability of the physical and chemical properties of zirconia ceramics, its poor adhesiveness has seriously affected the clinical application of zirconia ceramic prosthesis. OBJECTIVE: To analyze the effect of different surface treatment methods and resin cement on the bonding strength of zirconia ceramics. METHODS: Totally 240 zirconia blocks were randomly divided into 16 groups, with 15 in each group. In group A, the treatment method was sandblasting+hydrofluoric acid+Monobond-s+Panavia F 2.0. In group B, the treatment method was sandblasting+hydrofluoric acid+Monobond-s+Perma CemDual. In group C, the treatment method was sandblasting+hydrofluoric acid+new silane coupling agent+Panavia F 2.0. In group D, the treatment method was sandblasting+hydrofluoric acid+new silane coupling agent+Perma Cem-Dual. In group E, the treatment method was sandblasting+Monobond-s+Panavia F 2.0. In group F, the treatment method was sandblasting+Monobond-s+Perma Cem-Dual. In group G, the treatment method was sandblasting+Monobond-s+Panavia F 2.0 resin cement binder. In group H, the treatment method was sandblasting+new silane coupling agent+Perma Cem-Dual. In group I, the treatment method was hydrofluoric acid+Monobond-s+Panavia F 2.0. In group J, the treatment method was hydrofluoric acid+Monobond-s+Perma Cem-Dual. In group K, the treatment method was hydrofluoric acid+new silane coupling agent+Panavia F 2.0. In group L, the treatment method was hydrofluoric acid+new silane coupling agent+Perma Cem-Dual. In group M, the treatment method was Monobond-s+Panavia F 2.0. In group N, the treatment method was Monobond-s+Perma CemDual. In group O, the treatment method was new silane coupling agent+Panavia F 2.0. In group P, the treatment method was new silane coupling agent+Perma Cem-Dual. Panavia F 2.0 and Perma Cem-Dual were resin cement binders. Monobond-s was commercial silane coupling agent. The bonding strength of each group was tested. RESULTS AND CONCLUSION: (1) The bonding strength of groups C, G and H was higher than that of the remaining 13 groups (P < 0.05). The bonding strength of groups A, B, C, D, E, F, G and H was higher than that of groups I, J, K, L, M, N, and P (P < 0.05). (2) The results show that the combined use of zirconia sandblasting and new silane coupling agent can significantly improve the bonding strength of ceramic-cement. Hydrofluoric acid pretreatment is ineffective. The different types of cement will have a certain effect on the bonding strength.

Clinical application and prospects of zirconia bonding agent / 中国组织工程研究

BACKGROUND: Zirconia ceramic was considered as one of the optimal materials in prosthodontics and widely used in daily clinical treatment for its features, such as aesthetic properties, biocompatibility and corrosion resistance. Ideal bond strength and durability are necessary for the restoration to achieve satisfied clinical performance. OBJECTIVE: To systematically review zirconia and common zirconia bonding agents, the physical and chemical properties of zirconia ceramics, the clinical operating process standard, the common zirconia bonding agents and their bonding performance. METHODS: We searched the articles from March 2005 to March 2020 in PubMed, CNKI, Wanfang databases with the key words of “zirconia; surface treatment; universal adhesive; self-adhesive resin cement; bonding strength” in Chinese and English. After screening according to inclusion and exclusion criteria, the final 36 included articles were summarized. RESULTS AND CONCLUSION: Zirconia has excellent physical and chemical properties with hydrophobic surface, so it is difficult to form a proper bonding surface with the substrate. At present, the combination of physical sand blasting and chemical reaction is the most common treatment. The sand blasting can effectively increase the reaction area. In the aspect of chemical bonding, the bond strength of the self-adhesive resin cement can be significantly improved by both the universal adhesive and zirconia primer after 24 hours of water storage; however, the durability of universal adhesive is better than that of zirconia primer. As common sense, 37% phosphoric acid is daily used on tooth surface before bonding procedure, which can prohibit chemical reaction to zirconia. Sand blasting was considered as one of the most practical way to physically increase the surface for 10-MDP contained primers or universal adhesives chemically reacted with zirconia.

Influence of Shear Bonding Strength of Lithium Disilicate to Enamel under Different Surface Treatments.

Accurate diagnosis and proper treatment planning should be established before making any prosthetic rehabilitation to restore the good appearance of the tooth, a better smile, phonetics, and to achieve perfect occlusion/mastication. We wanted to evaluate the changes of surface treatment protocols on the tensile bonding strength between enamel and ceramic restorations (lithium disilicate).METHODSA total of 20 freshly extracted, non-carious teeth were stored in normal saline solution at 25°C until used. Clean enamel surfaces 2 mm X 2 mm were obtained from the extracted teeth by using wheel diamond bur. Each enamel side received one E-max sprue, so four sprues of different surface treatment protocols per tooth (G1 TS: Etching, bonding, and curing. CS: Etching, monobond, curing, overall light cure) (G2 TS: Bonding, curing, self-etch / self-adhesive resin cement, overall light cure. CS: Monobond etch and prime) (G3 TS: Etching, bonding without curing. CS: Etching, monobond, curing, overall light cure) (G4 TS: Etching, bonding, curing. CS: Etching, monobond, bonding, curing, light-cure resin cement, overall light cure). Tensile bonding strength was measured using the Instron testing machine. One-way ANOVA test was used to analyse the data.RESULTSThe highest mean was observed in Group 3 (124.34±43.47) followed by Group 1 (104.29±50.09), which is control group. In contrast, the lowest mean was observed in Group 2 (83.64 ± 53.56) and Group 4 (94.14±57.91). The results of ANOVA test have shown a significant difference between the surface treatment groups at 5% significance level.CONCLUSIONSHydrofluoric acid and primer/silane coupling agent create a porous surface on the ceramic that allow a good interaction with silane coupling agent.

Influencia del silano y adhesivos universales en la adhesión durante la reparación de un cerómero / Influence of silane and universal adhesives on adhesion during the repair of a ceromer

RESUMEN Introducción: No existe un protocolo definitivo para la reparación de cerómeros. Los adhesivos universales debido a su composición e indicaciones pueden ser una alternativa dentro de la reparación de restauraciones poliméricas, pero la asociación de los silanos con los adhesivos universales requiere más investigación. Objetivo: Evaluar y comparar la resistencia de unión de dos adhesivos universales en la interfase cerómero-resina, asociado o no a un agente silano. Material y métodos: Se realizaron seis bloques de cerómero y se trataron según las siguientes variables: (A) sin tratamiento, (B) agente silano, (C) adhesivo universal 1 + silano, (D) adhesivo universal 1, (E) adhesivo universal 2 + silano, (F) adhesivo universal 2 (n = 10). Se unió resina compuesta a dichas superficies y se realizó prueba de microtensión. El tipo de falla se evaluó con estereomicroscopio. Resultados: Los valores de resistencia de unión de los grupos fueron estadísticamente diferentes (p < 0.05), excepto entre ambos adhesivos universales evaluados. El grupo B presentó los valores más altos de resistencia adhesiva. Los grupos C y E obtuvieron valores de resistencia adhesiva menores en comparación con los grupos D y F. El tipo de falla predominante fue el adhesivo. Conclusión: El uso asociado de un silano funcional con los adhesivos universales no mejora los valores de resistencia adhesiva, por lo que debería evitarse. Como primera elección se recomienda el silano funcional, y en segundo grado, sólo usar adhesivos universales, pero no asociar los dos materiales en un mismo proceso adhesivo.

ABSTRACT Introduction: There is no definitive protocol for ceromer repairs. Universal adhesives due to their composition and indications may be an alternative for polymeric restorations repair. But the association of silanes with universal adhesives requires more research. Objective: To evaluate and compare the bond strength of two universal adhesives in ceromer - resin interface, associated or not with a silane agent. Material and methods: Six ceromer blocks were made and treated according to the following variables: (A) No treatment, (B) Silane agent, (C) Universal Adhesive 1 + Silane, (D) Universal Adhesive 1, (E) Adhesive Universal 2 + Silane, (F) Universal Adhesive 2 (n = 10). Composite resin was attached to these surfaces and a microtension test was performed. The type of failure was evaluated with a stereomicroscope. Results: The bond strength values of the groups were statistically different (p <0.05), except between both universal adhesives were evaluated. Group (B) presented the highest values of adhesive resistance. Groups (C and E) had lower adhesive strength values compared to groups (D and F). The most prevalent type of failure was the adhesive. Conclusion: The associated use of functional silane to universal adhesives does not improve adhesive strength values, so it should be avoided. As a first choice, functionalsilane is recommended, and in the second degree, only use universal adhesives, but do not associate the two materials in the same adhesive process.

Alternativas de tratamientos de superficie para adhesión de cerámica de disilicado de litio / Alternatives of surface treatments for adhesion of lithium disilicate ceramics

Introduction: the clinical success of a restoration is strongly associated with the quality and durability of the ceramic-cement resin interface. In order to obtain an adequate union between these materials of different nature surface treatments are used and achieve mechanical retention or chemical interaction. Objectives: to check if any method promotes a true chemical bond between lithium disilicate ceramics and resin cement. As well as determineif there is any treatment that reports bonding values comparable to hydrofluoric acid and silane (gold standard). Methods: a systematic literature review was developed based on the PRISMA strategy, where the databases were searched: Science Direct, Pubmed (MEDLINE), EMBASE, Springer Journal, SciELO with MeSH and free terms from 2005 to November 2016 for articles in English and Spanish on surface treatments for lithium disilicate. Results: from 58 publications selected a sample of 21 articles. Two articles reported high risk of bias. Conclusions: hydrofluoric acid and silane continue to be the method with the highest and most reliable adhesion values in the literature. Universal adhesives are an alternative to promote chemical adhesion additional to the silane. Diamond burs, Nd: YAG and Er: YAG laser are not recommended as surface treatments(AU)

Introducción: el éxito clínico de una restauración se asocia fuertemente a la calidad y duración de la interface cerámica-cemento resinoso. Para que exista una adecuada unión entre estos materiales de distinta naturaleza se emplean tratamientos de superficie para lograr una buena retención mecánica o interacción química. Objetivos: revisar si algún método promueve una verdadera adhesión química entre la cerámica de disilicato de litio y el cemento resinoso, así como determinar si existe algún tratamiento que reporte valores de unión comparables al ácido fluorhídrico y silano (patrón de oro). Métodos: se desarrolló una revisión sistemática de literatura basada en la estrategia PRISMA, donde se buscó en las bases de datos: Science Direct, Pubmed (MEDLINE), EMBASE, Springer Journal, SciELO con términos MeSH y libres desde el 2005 a noviembre de 2016 para artículos en inglés y español sobre tratamientos de superficie para disilicato de litio. Resultados: de 58 publicaciones, se seleccionó una muestra de 21 artículos. Dos artículos reportaron riesgo de sesgo alto. Conclusiones: el ácido fluorhídrico y silano continúan siendo el método con los valores de adhesión más altos y confiables de la literatura. Los adhesivos universales son una alternativa para promover adhesión química adicional al silano. Fresas diamantadas, laser Nd: YAG y Er:YAG no se recomienda como tratamientos de superficie(AU)

Effect of delayed time, surface treatment, and repair material on shear bond strength of repaired bis-acryl composite resin

PURPOSE: The aim of this study was to evaluate the effect of delayed time, surface treatment, and repair materials on repair of bisacryl composite resin through comparison of shear bond strength and to evaluate the utility of bis-acryl composite resin repair using polymethyl methacrylate resin. MATERIALS AND METHODS: A total of 90 bis-acryl composite resin specimens were fabricated and classified into 9 test groups, each of 10 pieces according to delayed time, surface treatment and repair material. The shear bond strength of each specimen was measured using a universal testing machine immediately after fabrication and analyzed using a statistical analysis program (IBM SPSS statistics 20). After the shear bond strength measurement, the fracture surface of the specimen was observed. RESULTS: The highest shear bond strength (17.54 ± 3.14 MPa) was observed in the experimental group bonded immediately with a light-curing flowable composite resin using a bonding agent. CONCLUSION: When repairing bis-acryl composite resin, it is necessary to consider whether to remake according to the delayed time. For effective repair, it is desirable to consider appropriate materials and surface treatment methods according to the site or purpose of use.

Effect of silane coupling agent on composite-composite bond strength: an in vitro study / 中华口腔医学杂志

Objective@#To investigate the effect of silane coupling agent on composite-composite bond strength, and to provide experimental basis for improving composite-composite bond strength clinically.@*Methods@#Self-etching adhesive Clearfil SE Bond (CSE) and silane-containing universal adhesive Single Bond Universal (SBU) were used as adhesives. A silane coupling agent (RelyX ceramic primer) was tested. P60 resin composite blocks were prepared and divided into 4 groups according to whether silane coupling agent was applied or the type of the adhesives: CSE group, in which CSE was applied as an adhesive; Silane + CSE group, in which the surface was treated with silane coupling agent followed by CSE; SBU group, in which SBU was applied as an adhesive; Silane+ SBU group, in which the surface was treated with silane coupling agent followed by SBU, then filling a new composite. All the composite blocks were cut into about twenty 1 mm×1 mm×14 mm samples to detect the micro-tensile bond strength. Fractographic analysis were performed under a three-dimensional laser scanning microscope. The micro-tensile bond strength data were analyzed statistically by one-way ANOVA and the failure pattern data were analyzed statistically by Chi-square test.@*Results@#Silane + SBU group [(69.6 ± 3.3) MPa] showed a significantly higher micro-tensile bond strength than the other groups (P<0.05). Silane+CSE group showed a significantly higher micro-tensile bond strength [(63.9±3.7) MPa] than CSE group [(55.7±4.2) MPa] and SBU group [(55.4±4.0) MPa] (P<0.05); There was no significant difference in micro-tensile bond strength between the SBU group and the CSE group (P>0.05). Failure patterns in the 4 groups were adhesive failure, cohesive failure and mixed failure. There was no significant difference in the proportion of adhesive failure between the Silane+CSE group and the Silane+SBU group, and the proportion of adhesive failure in these two groups were significantly less than that in the CSE and the SBU group (P<0.05).@*Conclusions@#Silane coupling agent pretreatment could improve composite-composite bond strength, however, the bond strength could not be higher when silane was mixed with adhesives in one bottle.

Effect of Different Silane Treatments on Long-Term Bonding Between Non-Etched Glass-Ceramic and Resin Cement

he present study evaluated the bond strength between glass-ceramic and resin cement, using different silane treatments, performing no previous hydrofluoric acid (HF) etching on ceramic surface, after short- and long- term storage. One hundred and eighty glass-ceramic plaques (IPS e.max CAD®) were polished and divided into six groups (n=30) to receive different silane treatments: (1) RCP-RelyX Ceramic Primer® (one-bottle silane), (2) RCP+SB-RelyX Ceramic Primer and Adper Singlebond2® (silane plus separated adhesive), (3) SBU-Scotchbond Universal® (silane-containing universal adhesive), (4) CP-Clearfil Ceramic Primer® (silane/MDP primer), (5) NC-no-silane (negative control) and (6) PC-Previous HF etching (5%, 20s) plus RelyX Ceramic Primer® (positive control). Two resin cement cylinders (Rely X Ultimate®) were built on each plaque. Each group was divided into two sub-groups to be stored for 24 hours (24h) or 6 months (6mo) in distilled water at 37°C (n=15). Then microshear (µSBS) testing was performed. Failure mode was analyzed using scanning electron microscopy (SEM). Data were statistically analyzed by two-way ANOVA and Tukey´s test (α=0.05). Both factors and their interaction resulted statistically significant (p≤0.05). PC obtained the highest µSBS values (in MPa) at both storage times (24h: 28.11±2.44; 6mo: 19.10±3.85). After 24h storage, groups RCP+SB (10.86±3.62), SBU (8.37±4.33) and CP (8.05±3.62) were not statistically different from NC (8.00±2.51); only RCP (19.73±4.63) and PC obtained higher values. After 6 months, only PC showed higher values than NC (0.04±0.01). Cohesive failure in resin cement was more prevalent for RCP-24h and PC, while adhesive failure was more frequent among all other groups. Clinical relevance: None of the commercially available silane primers tested, improve long- term ceramic/cement bonding without performing HF etching on ceramic surface. Combination of HF acid and silane, remain as a gold standard treatment for glass-ceramic materials.

ste estudio evaluó la resistencia de unión entre cerámica vítrea y cemento resinoso, utilizando diferentes tratamientos de silano, sin realizar condicionamiento previo de la cerámica con ácido fluorhídrico (HF), después de almacenamiento en corto y largo plazo. Ciento ochenta placas de cerámica (IPS e.max CAD®) fueron pulidas y divididas en 6 grupos (n=30) para ser tratadas como sigue: (1) RCPRelyX Ceramic Primer® (silano de 1 frasco), (2) RCP+SB-RelyX Ceramic Primer y Adper Singlebond2® (silano más adhesivo separado), (3) SBU-Scotchbond Universal® (adhesivo universal conteniendo silano), (4) CP-Clearfil Ceramic Primer® (primer cerámico conteniendo silano y MDP), (5) NC-ningún silano (control negativo) y (6) PC-Condicionamiento con HF previo (5%, 20s) y silano (RelyX Ceramic Primer®) (control positivo). Dos cilindros de cemento resinoso (Rely X Ultimate®) fueron construidos en cada placa. Cada grupo fue dividido en 2 sub-grupos para ser almacenados por 24 horas (24h) y 6 meses (6mo) en agua destilada a 37°C (n=15). Luego fue realizada la prueba de microcizallamiento (µSBS). El tipo de fractura fue analizado con microscopio electrónico de barrido (SEM) y los datos analizados con las pruebas estadísticas ANOVA de dos factores y Tukey (α=0.05). Ambos factores y su interacción resultaron estadísticamente significativos (p≤0.05). PC presentó los valores más altos de µSBS (MPa) para ambos tiempos de almacenamiento (24h: 28.11±2.44; 6mo: 19.10±3.85). Luego de 24h, los grupos RCP+SB (10.86±3.62), SBU (8.37±4.33) y CP (8.05±3.62) no fueron estadísticamente diferentes del grupo control negativo (NC: 8.00±2.51); sólo RCP (19.73±4.63) y PC obtuvieron resultados mayores. Después de 6 meses de almacenaje, sólo el grupo PC obtuvo valores estadísticamente mayores que NC (0.04±0.01). Fractura cohesiva en el cemento fue más prevalente para RCP-24h y PC, mientras que el tipo adhesivo fue el más frecuente para todos los demás grupos. Relevancia Clínica: Ninguno de los tratamientos de silano evaluados, mejoró significativamente la adhesión a largo plazo entre cerámica vítrea no condicionada y cemento resinoso. La combinación de HF y silano, continúa siendo el tratamiento de preferencia para cerámica vítrea durante el proceso de cementación.

Influence of different treatments of the ceramic surface and thermal cycling on the bond strength of brackets to ceramic / Influência de diferentes tratamentos de superfície da cerâmica e ciclagem térmica na resistência de união de bráquetes à cerâmica

Objective: To evaluate in vitro the effect of different treatments of the ceramic surface and thermal cycling on the shear bond strength (SBS) of metallic brackets bonded to feldspathic ceramic. Material and method: Ceramic cylinders were divided into four groups (n=4) according to the treatment of ceramic surface: G1-Clearfil Ceramic Primer silane and Transbond XT (CCPT); G2-etched with 10% hydrofluoric acid (HFA) for 60 s, CCP and Transbond XT (ACCPT); G3-etched with 10% HFA for 60 s, Ambar Adhesive and Transbond XT (AAAT); and, G4 - etched with 10% HFA for 60 s, RelyX Ceramic Primer silane -RCP, adhesive primer Transbond and Transbond XT (ACPPT). Brackets were bonded to the cylinders with Transbond XT and light-activated for 40 s with LED Radii Plus. All specimens were stored in deionized water at 37 °C for 24 h, and two cylinders from each group were subject to 7,000 thermal cycles in a thermal cycler (5 °C/55 °C). After storage and thermal cycling, the SBS test was performed at a crosshead speed of 1 mm/min. Data were subjected to two-way ANOVA and Tukey's post hoc test (α=0.05). Result: The SBS of ACCPT was significantly higher than the other groups (p<0.05). The specimens submitted to thermal cycling showed significantly lower SBS than those without thermal cycling (p<0.05), regardless the ceramic surface treatment. The ARI showed predominance of score 0 for all groups. Conclusion: Acid etching, CCP silane and Transbond XT method obtained the best results for bracket bonding. Thermal cycling reduced SBS for all groups. Score 0 was predominant for ARI in all groups.

Objetivo: Avaliar in vitro o efeito de diferentes tratamentos de superfície da cerâmica e ciclagem térmica na resistência da união ao cisalhamento (RUC) de bráquetes metálicos colados na cerâmica felspática. Material e método: Cilindros cerâmicos foram separados em 4 grupos (n=4) de acordo com os tratamentos da superfície da cerâmica: G1-Clearfil Ceramic Primer silano e Transbond XT (CCPT); G-condicionamento com ácido hidrofluorídrico a 10% (AHF) por 60s, CCP e Transbond XT (ACCPT); G3-condicionamento com AHF a 10% por 60s, Adesivo Ambar e Transbond XT (AAAT); e, G4 condicionamento com AHF a 10% por 60s, RelyX Ceramic Primer silano, primer adesivo Transbond e Transbond XT (ACPAT). Os bráquetes foram fixados nos cilindros com Transbond XT e fotoativado por 40s com LED Radii Plus. Todas as amostras foram armazenadas em água deionizada a 37 °C por 24 h e dois cilindros de cada grupo foram submetidos a 7.000 ciclos térmicos na máquina para ciclagem térmica (5 °C/55 °C). Após armazenagem e ciclagem térmica, a RUC foi realizada à velocidade de 1 mm/min. Na Análise de Variância de 2 fatores e ao teste de Tukey's post hoc test (α=0,05) a RUC do G2 foi significante maior do que dos demais grupos (p<0,05). Resultado: As amostras submetidas à ciclagem térmica apresentaram valores de RUC significantemente menores do que as amostras sem ciclagem térmica (p<0,05), independente do tratamento de superfície da cerâmica. Conclusão: Nas condições desse estudo o melhor resultado para colagem foi obtido com o condicionamento, silano CCP e Transbond XT. A ciclagem térmica reduziu a RUC em todos os grupos.

Microtensile bond strength of repaired indirect resin composite

PURPOSE: The objective of this study was to investigate the effect of surface treatments on microtensile bond strengths (MTBSs) of two types of indirect resin composites bonded to a conventional direct resin composite. MATERIALS AND METHODS: Indirect resin composite blocks of Ceramage and SR Nexco were prepared in a plastic mold having a dimension of 10 × 10 × 4 mm. These composite blocks were divided into three groups according to their surface treatments: Group1: Sandblast (SB); Group2: Sandblast and ultrasonically clean (SB+UL); Group3: Sandblast plus silane (SB+SI). After bonding with direct resin composite, indirect-direct resin composite blocks were kept in distilled water for 24 hours at 37℃ and cut into microbars with the dimension of 1 × 1 × 8 mm. Microbar specimens (n = 40 per group) were loaded using a universal testing machine. Failure modes and compositions were evaluated by SEM. The statistical analyses of MTBS were performed by two-way ANOVA and Dunnett's test at α = .05. RESULTS: Surface treatments and brands had effects on the MTBS without an interaction between these two factors. For SR Nexco, the MTBSs of SB and SB+SI group were significantly higher than that of SB+UL. For Ceramage, the MTBSs of SB and SB+SI were significantly higher than that of SB+UL. The mean MTBS of the Ceramage specimens was significantly higher than that of SR Nexco for all surface treatments. CONCLUSION: Sandblasting with or without silane application could improve the bond strengths of repaired indirect resin composites to a conventional direct resin composite.

Bonding of the silane containing multi-mode universal adhesive for lithium disilicate ceramics

OBJECTIVES: This study evaluated the influence of a multi-mode universal adhesive (MUA) containing silane (Single Bond Universal, 3M EPSE) on the bonding of resin cement to lithium disilicate. MATERIALS AND METHODS: Thirty IPS e.max CAD specimens (Ivoclar Vivadent) were fabricated. The surfaces were treated as follows: Group A, adhesive that did not contain silane (ANS, Porcelain Bonding Resin, Bisco); Group B, silane (S) and ANS; Group C, hydrofluoric acid (HF), S, and ANS; Group D, MUA; Group E, HF and MUA. Dual-cure resin cement (NX3, Kerr) was applied and composite resin cylinders of 0.8 mm in diameter were placed on it before light polymerization. Bonded specimens were stored in water for 24 hours or underwent a 10,000 thermocycling process prior to microshear bond strength testing. The data were analyzed using multivariate analysis of variance (p < 0.05). RESULTS: Bond strength varied significantly among the groups (p < 0.05), except for Groups A and D. Group C showed the highest initial bond strength (27.1 ± 6.9 MPa), followed by Group E, Group B, Group D, and Group A. Thermocycling significantly reduced bond strength in Groups B, C, and E (p < 0.05). Bond strength in Group C was the highest regardless of the storage conditions (p < 0.05). CONCLUSIONS: Surface treatment of lithium disilicate using HF and silane increased the bond strength of resin cement. However, after thermocycling, the silane in MUA did not help achieve durable bond strength between lithium disilicate and resin cement, even when HF was applied.

Kinematic and spermatic recovery after selection by centrifugation in colloid solutions of ovine cryopreserved semen / Cinética e recuperação espermática após seleção por centrifugação em soluções coloidais de sêmen ovino criopreservado

Frozen and thawed ovine semen undergo morphological and functional changes that prevent or decrease the efficiency of fertilization. Sperm selection methods seek to improve the quality and viability of the fertilizing materials. Four sperm selection methods were employed, using two silica colloidal solutions coated with silane (silica colloidal-silane) or by polyvinylpyrrolidone (silica colloidal-PVP), and varying the volume of colloidal solution. Sperm kinematic and sperm recovery were evaluated by means of CASA. The protocols using silica colloidal-silane showed higher total motility (TM), progressive motility (PM) and percentage of rapid sperm (%RAP) compared to the methods employing silica colloidal-PVP and to the samples prior to sperm selection. The silica colloidal-PVP had greater sperm recovery compared to the silica colloidal-silane. Only the method using 4mL of silica colloidal-PVP was not efficient in selecting samples with better quality compared to the samples analyzed prior to sperm selection. The methods using lower volumes of colloidal solution did not differ from those using higher volumes and the best results were shown by the method with 1mL silica colloidal-silane. The results found in the study indicated greater efficiency of the silica colloidal-silane solution for sperm selection of thawed ovine semen when compared to selection using silica colloidal-PVP. The method using 1mL of silica colloidal-silane was equally efficient to the method with higher volume, presenting itself as an alternative to process samples with lower sperm concentration.(AU)

O sêmen ovino congelado e descongelado sofre alterações morfofuncionais que impossibilitam ou diminuem a eficiência na fecundação. Os métodos de seleção espermática visam melhorar a qualidade e a viabilidade do material fecundante. Foram utilizados quatro métodos de seleção espermática utilizando duas soluções de sílica coloidal revestida por silano (sílica coloidal-silano) ou por polivinilpirrolidona (sílica coloidal-PVP), variando o volume de solução coloidal. Foram testadas a cinética espermática no CASA e a recuperação espermática. Os protocolos utilizando sílica coloidal-silano apresentaram maior motilidade total (MT), motilidade progressiva (MP) e porcentagem de espermatozoides rápidos (% RAP) quando comparados aos métodos utilizando a sílica coloidal-PVP e às amostras antes da seleção espermática. A sílica coloidal-PVP teve maior recuperação espermática quando comparada à sílica coloidal-silano. Somente o método utilizando 4mL de sílica coloidal-PVP não foi eficiente na seleção de amostras com melhor qualidade quando comparado às amostras analisadas antes da seleção espermática. Os métodos utilizando menores volumes de solução coloidal não diferiram dos métodos de maior volume, sendo a sílica coloidal-silano com 1mL o método que apresentou os melhores resultados. Como conclusão, os resultados encontrados no trabalho apontaram a maior eficiência da sílica coloidal-silano em selecionar sêmen ovino congelado e descongelado quando comparado à seleção em sílica coloidal-PVP. O método utilizando 1mL de sílica coloidal-silano foi igualmente eficiente ao método com maior volume, sendo uma alternativa para processar amostras com baixa concentração espermática.(AU)

Effect of Acid Etching, Silane and Thermal Cycling on the Bond Strength of Metallic Brackets to Ceramic

Abstract The aim of this study was to evaluate the effect of silanes, thermal cycling and acid etching on the shear bond strength (SBS) of metallic brackets to feldspathic ceramic. Feldspathic ceramic cylinders (Groups 1, 2, 5 and 6) were etched for 60 s with 10% hydrofluoric acid and Groups 3, 4, 7 and 8, without acid etching. Two layers of silane Clearfil Ceramic Primer (CCP, Groups 1 to 4) and two layers of RelyX Ceramic Primer (RCP, groups 5 to 8) were applied and dried for 60 s. Brackets were bonded to the cylinders with Transbond XT and light-activated for 40 s with Bluephase G2. All specimens were stored in deionized water at 37 °C for 24 h, and the specimens of groups 1, 3, 5 and 7 were submitted to 7,000 thermal cycles (5 °C/55 °C). After storage, the SBS test was performed at a crosshead speed of 1 mm/min. Data were subjected to three-way ANOVA and Tukey's post hoc test (α=0.05). The adhesive remnant index (ARI) was evaluated at 8x magnification. The SBS of CCP was significantly greater than of RCP (p<0.05), with or without thermal cycling. Thermal cycling significantly reduced the SBS (p<0.05). The groups submitted to acid etching showed significantly higher SBS than those without acid etching (p<0.05). In conclusion, thermal cycling reduced SBS for all groups. The best ceramic surface treatment for bracket bonding was achieved by acid etching and CCP silane. The ARI results showed predominance of score 0 for all groups.

Resumo O objetivo neste estudo foi avaliar o efeito de diferentes silanos, ciclagem térmica e condicionamento ácido na resistência da união ao cisalhamento (RUC) de bráquetes metálicos a cerâmica feldspática. Cilindros da cerâmica feldspática (Grupos 1, 2, 5 e 6) foram condicionados por 60 s com ácido hidrofluorídrico a 10% e os Grupos 3, 4, 7 e 8 sem condicionamento ácido. Duas camadas do silano Clearfil Ceramic Primer (CCP, Grupos 1 a 4) e duas camadas do RelyX Ceramic Primer (RCP, Grupos 5 a 8) foram aplicadas e secas por 60 s. Bráquetes foram fixados aos cilindros cerâmicos usando Transbond XT e fotoativado por 40 s com Bluephase G2. Todas as amostras foram armazenadas em água deionizada a 37 °C por 24 h, sendo as amostras dos grupos 1, 3, 5 e 7 submetidas a 7.000 ciclos térmicos (5 °C/55 °C). Após a armazenagem, a RUC foi verificada a velocidade de 1 mm/min. Os dados foram submetidos à ANOVA 3 fatores e teste de Tukey post hoc (α=0,05). O Índice de Remanescente do Adesivo (IRA) foi avaliado com aumento de 8x. A RUC do CCP foi significantemente maior do que o RCP (p<0,05), com ou sem ciclagem térmica. A ciclagem térmica reduziu significantemente a RUC (p<0,05). Os grupos submetidos ao condicionamento ácido mostraram valores de RUC significantemente maiores em relação os grupos sem condicionamento ácido (p<0,05). Concluindo, a ciclagem térmica reduziu a RUC para todos os grupos. O melhor tratamento de superfície da cerâmica para colagem de bráquetes foi obtido pelo condicionamento ácido e pelo silano CCP. O IRA mostrou predominância de escore 0 para todos os grupos.

Acid Etching and Surface Coating of Glass-Fiber Posts: Bond Strength and Interface Analysis

Abstract The aim of this study was to evaluate the bond strength of a composite resin to glass-fiber post (GFP) treated or not with phosphoric acid, silane coupling agent, and unfilled resin. GFPs were etched or not with 37% phosphoric acid and different surface coating applied: silane coupling agent, unfilled resin, or both. Composite resin blocks were built around a 4-mm height on the GFP. Unfilled resin (20 s) and composite resin (40 s) were light activated by a light-emitting diode unit. The specimens were stored in distilled water at 37 °C for 24 h. Microtensile bond test was performed using a mechanical testing machine until failure (n=10). The data were analyzed using two-way ANOVA followed by Student-Newman-Keuls' test (p<0.05). Failure modes were classified as adhesive, mixed, or cohesive failures. Additional specimens (n=3) were made to analyze the bonded interfaces by scanning electron microscopy. The statistical analysis showed the factor 'surface coating' was significant (p<0.05), whereas the factor 'HP etching' (p=0.131) and interaction between the factors (p=0.171) were not significant. The highest bond strength was found for the silane and unfilled resin group (p<0.05). A predominance of adhesive and cohesive failures was found. Differences regarding the homogeneity and thickness of the unfilled resin layer formed by different GFP surface treatments were observed. The application of silane and unfilled resin can improve the bond strength between GFP and resin composite.

Resumo O objetivo deste estudo foi avaliar o efeito resistência de união de uma resina composta para pinos de fibra de vidro (PFV) tratados ou não com ácido fosfórico, agente de união (silano) e adesivo. PFVs foram condicionados ou não com ácido fosfórico 37% e receberam aplicação de diferentes materiais: um agente de união, um adesivo, ou ambos. Blocos em resina composta foram construídos a 4 mm de altura no PFV. O adesivo (20 s) e a resina composta (40 s) foram fotoativado por um diodo emissor de luz. As amostras foram armazenadas em água destilada a 37 C por 24 h. O teste de microtração foi realizado em uma máquina de ensaio universal (n=10). Os dados foram analisados usando ANOVA dois fatores e teste de Student-Newman-Keuls (p<0,05). Os padrões de fratura foram classificados em falhas adesivas, mistas ou coesivas. Amostras adicionais (n=3) foram feitas para análise da interface de união em microscopia eletrônica de varredura. A análise estatística mostrou que o fator 'recobrimento da superfície' foi significante (p<0,05), enquanto que o fator 'ácido fosfórico' (p=0,131) e a interação entre os fatores (p=0.171) não foram significantes. A maior resistência da união foi encontrada para os grupos silano e adesivo (p<0,05). Uma predominância de falhas adesivas e coesivas foi encontrada. Foram observadas diferenças em relação à homogeneidade e espessura da camada adesiva formada sobre os PFV com os diferentes tratamentos de superfície. Aplicação de silano e adesivo pode melhorar a resistência de união entre PFV e resina composta.

The effect of silane applied to glass ceramics on surface structure and bonding strength at different temperatures

PURPOSE: To evaluate the effect of various surface treatments on the surface structure and shear bond strength (SBS) of different ceramics. MATERIALS AND METHODS: 288 specimens (lithium-disilicate, leucite-reinforced, and glass infiltrated zirconia) were first divided into two groups according to the resin cement used, and were later divided into four groups according to the given surface treatments: G1 (hydrofluoric acid (HF)+silane), G2 (silane alone-no heat-treatment), G3 (silane alone-then dried with 60℃ heat-treatment), and G4 (silane alone-then dried with 100℃ heat-treatment). Two different adhesive luting systems were applied onto the ceramic discs in all groups. SBS (in MPa) was calculated from the failure load per bonded area (in N/mm2). Subsequently, one specimen from each group was prepared for SEM evaluation of the separated-resin–ceramic interface. RESULTS: SBS values of G1 were significantly higher than those of the other groups in the lithium disilicate ceramic and leucite reinforced ceramic, and the SBS values of G4 and G1 were significantly higher than those of G2 and G3 in glass infiltrated zirconia. The three-way ANOVA revealed that the SBS values were significantly affected by the type of resin cement (P<.001). FIN ceramics had the highest rate of cohesive failure on the ceramic surfaces than other ceramic groups. AFM images showed that the surface treatment groups exhibited similar topographies, except the group treated with HF. CONCLUSION: The heat treatment was not sufficient to achieve high SBS values as compared with HF acid etching. The surface topography of ceramics was affected by surface treatments.

Effects of hydrogen peroxide pretreatment and heat activation of silane on the shear bond strength of fiber-reinforced composite posts to resin cement

PURPOSE: To evaluate the effects of hydrogen peroxide pretreatment and heat activation of silane on the shear bond strength of fiber-reinforced composite posts to resin cement. MATERIALS AND METHODS: The specimens were prepared to evaluate the bond strength of epoxy resin-based fiber posts (D.T. Light-Post) to dual-curing resin cement (RelyX U200). The specimens were divided into four groups (n=18) according to different surface treatments: group 1, no treatment; group 2, silanization; group 3, silanization after hydrogen peroxide etching; group 4, silanization with warm drying at 80℃ after hydrogen peroxide etching. After storage of the specimens in distilled water at 37℃ for 24 hours, the shear bond strength (in MPa) between the fiber post and resin cement was measured using a universal testing machine. The fractured surface of the fiber post was examined using scanning electron microscopy. Data were analyzed using one-way ANOVA and post-hoc analysis with Tukey's HSD test (α=0.05). RESULTS: Silanization of the fiber post (Group 2) significantly increased the bond strength in comparison with the non treated control (Group 1) (P.05). CONCLUSION: Fiber post silanization and subsequent heat treatment (80℃) with warm air blower can be beneficial in clinical post cementation. However, hydrogen peroxide etching prior to silanization was not effective in this study.