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The aim of this study was to evaluate the effects of different light-curing units and resin cement curing types on the bond durability of a feldspathic ceramic bonded to dentin. The crowns of 40 human molars were sectioned, exposing the dentin. Forty ceramic blocks of VITA VM7 were produced according to the manufacturer's recommendations. The ceramic surface was etched with 10% hydrofluoric acid / 60s and silanized. The dentin was treated with 37% phosphoric acid / 15s, and the adhesive was applied. The ceramic blocks were divided and cemented to dentin according to resin cement / RC curing type (dual- and photo-cured), light-curing unit (halogen light / QTH and LED), and storage conditions (dry and storage / 150 days + 12,000 cycles / thermocycling). All blocks were stored in distilled water (37°C / 24h) and sectioned (n = 10): G1 - QTH + RC Photo, G2 - QTH + RC Dual, G3 - LED + RC Photo, G4 - LED + RC Dual. Groups G5, G6, G7, and G8 were obtained exactly as G1 through G4, respectively, and then stored and thermocycled. Microtensile bond strength tests were performed (EMIC), and data were statistically analyzed by ANOVA and Tukey's test (5%). The bond strength values (MPa) were: G1 - 12.95 (6.40)ab; G2 - 12.02 (4.59)ab; G3 - 13.09 (5.62)ab; G4 - 15.96 (6.32)a; G5 - 6.22 (5.90)c; G6 - 9.48 (5.99)bc; G7 - 12.78 (11.30)ab; and G8 - 8.34 (5.98)bc. The same superscript letters indicate no significant differences. Different light-curing units affected the bond strength between ceramic cemented to dentin when the photo-cured cement was used, and only after aging (LED > QTH). There was no difference between the effects of dual- and photo-cured resin-luting agents on the microtensile bond strength of the cement used in this study.

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The aim of this study was to evaluate the effects of different light-curing units and resin cement curing types on the bond durability of a feldspathic ceramic bonded to dentin. The crowns of 40 human molars were sectioned, exposing the dentin. Forty ceramic blocks of VITA VM7 were produced according to the manufacturer's recommendations. The ceramic surface was etched with 10% hydrofluoric acid / 60s and silanized. The dentin was treated with 37% phosphoric acid / 15s, and the adhesive was applied. The ceramic blocks were divided and cemented to dentin according to resin cement / RC curing type (dual- and photo-cured), light-curing unit (halogen light / QTH and LED), and storage conditions (dry and storage / 150 days + 12,000 cycles / thermocycling). All blocks were stored in distilled water (37°C / 24h) and sectioned (n = 10): G1 - QTH + RC Photo, G2 - QTH + RC Dual, G3 - LED + RC Photo, G4 - LED + RC Dual. Groups G5, G6, G7, and G8 were obtained exactly as G1 through G4, respectively, and then stored and thermocycled. Microtensile bond strength tests were performed (EMIC), and data were statistically analyzed by ANOVA and Tukey's test (5%). The bond strength values (MPa) were: G1 - 12.95 (6.40)ab; G2 - 12.02 (4.59)ab; G3 - 13.09 (5.62)ab; G4 - 15.96 (6.32)a; G5 - 6.22 (5.90)c; G6 - 9.48 (5.99)bc; G7 - 12.78 (11.30)ab; and G8 - 8.34 (5.98)bc. The same superscript letters indicate no significant differences. Different light-curing units affected the bond strength between ceramic cemented to dentin when the photo-cured cement was used, and only after aging (LED > QTH). There was no difference between the effects of dual- and photo-cured resin-luting agents on the microtensile bond strength of the cement used in this study.

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PURPOSE: Adhesive cementation is an important step for restorations made of feldspathic ceramic as it increases the strength of such materials. Incorrect selection of the adhesive resin and the resin cement to adhere to the ceramic surface and their durability against aging can affect the adhesion between these materials and the clinical performance. This study evaluated the effect of adhesive resins with different pHs, resin cements with different polymerization modes, and aging on the bond strength to feldspathic ceramic. MATERIALS AND METHODS: One surface of feldspathic ceramic blocks (VM7) (N = 90) (6.4 × 6.4 × 4.8 mm(3) ) was conditioned with 10% hydrofluoric acid for 20 seconds, washed/dried, and silanized. Three adhesive resins (Scotchbond Multi-Purpose Plus [SBMP], pH: 5.6; Single Bond [SB], pH: 3.4; and Prime&Bond NT [NT], pH: 1.7) were applied on the ceramic surfaces (n = 30 per adhesive). For each adhesive group, three resin cements with different polymerization modes were applied (n = 10 per cement): photo-polymerized (Variolink II base), dual polymerized (Variolink II base + catalyst), and chemically polymerized (C&B). The bonded ceramic blocks were stored in water (37°C) for 24 hours and sectioned to produce beam specimens (cross-sectional bonded area: 1 ± 0.1 mm(2) ). The beams of each block were randomly divided into two conditions: Dry, microtensile test immediately after cutting; TC, test was performed after thermocycling (12,000×, 5°C to 55°C) and water storage at 37°C for 150 days. Considering the three factors of the study (adhesive [3 levels], resin cement [3 levels], aging [2 levels]), 18 groups were studied. The microtensile bond strength data were analyzed using 3-way ANOVA and Tukey's post hoc test (α= 0.05). RESULTS: Adhesive resin type (p < 0.001) and the resin cement affected the mean bond strength (p= 0.0003) (3-way ANOVA). The NT adhesive associated with the chemically polymerized resin cement in both dry (8.8 ± 6.8 MPa) and aged conditions (6.9 ± 5.9 MPa) presented statistically lower bond strength results, while the SBMP adhesive resin, regardless of the resin cement type, presented the highest results (15.4 to 18.5 and 14.3 to 18.9 MPa) in both dry and aged conditions, respectively (Tukey's test). CONCLUSION: Application of a low-pH adhesive resin onto a hydrofluoric acid etched and silanized feldspathic ceramic surface in combination with chemically polymerized resin cement did not deliver favorable results. The use of adhesive resin with high pH could be clinically advised for the photo-, dual-, and chemically polymerized resin cements tested.

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PURPOSE: To evaluate the effect of cement shade, light-curing unit, and water storage on tensile bond strength (σ) of a feldspathic ceramic resin bonded to dentin. MATERIALS AND METHODS: The dentin surface of 40 molars was exposed and etched with 37% phosphoric acid, then an adhesive system was applied. Forty blocks of feldspathic ceramic (Vita VM7) were produced. The ceramic surface was etched with 10% hydrofluoric acid for 60 s, followed by the application of a silane agent and a dual-curing resin cement (Variolink II). Ceramic blocks were cemented to the treated dentin using either A3 or transparent (Tr) shade cement that was activated using either halogen or LED light for 40 s. All blocks were stored in 37°C distilled water for 24 h before cutting to obtain non-trimmed bar-shaped specimens (adhesive area = 1 mm2 ± 0.1) for the microtensile bond strength test. The specimens were randomly grouped according to the storage time: no storage or stored for 150 days in 37°C distilled water. Eight experimental groups were obtained (n = 30). The specimens were submitted to the tensile bond strength test using a universal testing machine at a crosshead speed of 1 mm/min. The data were statistically analyzed using ANOVA and Tukey's posthoc tests (a = 0.05). RESULTS: The mean bond strength values were significantly lower for the corresponding water stored groups, except for the specimens using A3 resin cement activated by halogen light. There was no significance difference in mean bond strength values among all groups after water storage. CONCLUSION: Water storage had a detrimental effect under most experimental conditions. For both cement shades investigated (Tr and A3) under the same storage condition, the light-curing units (QTH and LED) did not affect the mean microtensile bond strengths of resin-cemented ceramic to dentin.

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PURPOSE: To evaluate the shear bond strength and bond durability between a dual-cured resin cement (RC) and a high alumina ceramic (In-Ceram Alumina), subjected to two surface treatments. MATERIALS AND METHODS: Forty disc-shaped specimens (sp) (4-mm diameter, 5-mm thick) were fabricated from In-Ceram Alumina and divided into two groups (n = 20) in accordance with surface treatment: (1) sandblasting by aluminum oxide particles (50 µm Al(2) O(3) ) (SB) and (2) silica coating (30 µm SiO(x) ) using the CoJet system (SC). After the 40 sp were bonded to the dual-cured RC, they were stored in distilled water at 37°C for 24 hours. After this period, the sp from each group were divided into two conditions of storage (n = 10): (a) 24 h-shear bond test 24 hours after cementation; (b) Aging-thermocycling (TC) (12,000 times, 5 to 55°C) and water storage (150 days). The shear test was performed in a universal test machine (1 mm/min). RESULTS: ANOVA and Tukey (5%) tests noted no statistically significant difference in the bond strength values between the two surface treatments (p = 0.7897). The bond strengths (MPa) for both surface treatments reduced significantly after aging (SB-24: 8.2 ± 4.6; SB-Aging: 3.7 ± 2.5; SC-24: 8.6 ± 2.2; SC-Aging: 3.5 ± 3.1). CONCLUSION: Surface conditioning using airborne particle abrasion with either 50 µm alumina or 30 µm silica particles exhibited similar bond strength values and decreased after long-term TC and water storage for both methods.

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The aim of this study was to determine the influence of different types of posts and post head designs on the fracture resistance of a composite resin core material using the diametral tensile strength (DTS ). Seventy-five disc specimens were prepared using a composite core and prefabricated glass fiber posts and were divided into four test groups and one control group (n=15). The use of fiber posts reduced the DTS of the composite core material; the DTS value of the control material was significantly higher (p=0.05) than all of the test groups.

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PURPOSE: This study evaluated the effect of cutting initiation location and cutting speed on the bond strength between resin cement and feldspathic ceramic. MATERIALS AND METHODS: Thirty-six blocks (6.4 x 6.4 x 4.8 mm) of ceramic (Vita VM7) were produced. The ceramic surfaces were etched with 10% hydrofluoric acid gel for 60 s and then silanized. Each ceramic block was placed in a silicon mold with the treated surface exposed. A resin cement (Variolink II) was injected into the mold over the treated surface and polymerized. The resin cement-ceramic blocks were divided into two groups according to experimental conditions: a) cutting initiation location - resin cement, ceramic and interface; and b) cutting speed - 10,000, 15,000, and 20,000 rpm. The specimens were sectioned to achieve non-trimmed bar specimens. The microtensile test was performed in a universal testing machine (1 mm/min). The failure modes were examined using an optical light microscope and SEM. Bond strength results were analyzed using one-way ANOVA and Tukey's test (α = 0.05). RESULTS: Significant influences of cutting speed and initiation location on bond strength (p < 0.05) were observed. The highest mean was achieved for specimens cut at 15,000 rpm at the interface (15.12 ± 5.36 MPa). The lowest means were obtained for specimens cut at the highest cutting speed in resin cement (8.50 ± 3.27 MPa), and cut at the lowest cutting speed in ceramic (8.60 ± 2.65 MPa). All groups showed mainly mixed failure (75% to 100%). CONCLUSION: The cutting speed and initiation location are important factors that should be considered during specimen preparation for microtensile bond strength testing, as both may influence the bond strength results.

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The purpose of this study was to determine the accuracy of mechanical torque devices in delivering target torque values in dental offices in Salvador, Brazil. A team of researchers visited 16 dental offices, and the clinicians applied torque values (20 and 32 Ncm) to electronic torque controllers. Five repetitions were completed at each torque value and data were collected. When 20 Ncm of torque was used, 62.5% of measured values were accurate (within 10% of the target value). For 32 Ncm, however, only 37.5% of these values were achieved. Several of the tested mechanical torque devices were inaccurate.

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PURPOSE: This study evaluated the adhesive quality of simplified self-adhesive and conventional resin cements to Y-TZP in dry and aged conditions. METHODS: Y-TZP ceramic blocks (N = 192) (5 x 5 x 2 mm) were embedded in acrylic resin and randomly divided into two groups, based on surface conditioning: 96% isopropanol or chairside tribochemical silica coating and silanization. Conditioned ceramics were divided into four groups to receive the resin cements (Panavia F 2.0, Variolink II, RelyX U100 and Maxcem). After 24 hours, half of the specimens (n = 12) from each group were submitted to shear bond strength testing (0.5 mm/minute). The remaining specimens were tested after 90 days of water storage at 37 degrees C and thermocycling (12,000x, 5 degrees C-55 degrees C). Failure types were then assessed. The data were analyzed using three-way ANOVA and the Tukey's test (alpha = 0.05). RESULTS: Significant effects of ceramic conditioning, cement type and storage conditions were observed (p < 0.0001). The groups cleaned using alcohol only showed low bond strength values in dry conditions and the bond strength was reduced dramatically after aging. Groups conditioned using silica coating and silanization showed higher bond strengths both in dry and aged conditions. A high number of specimens failed prematurely prior to testing when they were cleaned using 96% isopropanol. CONCLUSION: Overall, silica coating and silanization showed higher, stable bond strengths with and without aging. The durability of resin-ceramic adhesion varied, depending on the adhesive cement type.

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The aim of this study was to evaluate the influence of silica coating and 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-based primer applications upon the bonding durability of a MDP-based resin cement to a yttrium stabilized tetragonal zirconia (Y-TZP) ceramic. Ninety-six Y-TZP tabs were embedded in an acrylic resin (free surface for adhesion: 5 × 5 mm(2)), ground finished and randomly divided into four groups (N = 24) according to the ceramic surface conditioning: (1) cleaning with isopropanol (ALC); (2) ALC + phosphoric acid etching + MDP-based primer application (MDP-primer); (3) silica coating + 3-methacryloyloxypropyl trimethoxysilane (MPS)-based coupling agent application (SiO2 + MPS-Sil); and (4) SiO2 + MDP-primer. The MDP-based resin cement was applied on the treated surface using a cylindrical mold (diameter= 3 mm). Half of the specimens from each surface conditioning were stored in distilled water (37 °C, 24 h) before testing. Another half of the specimens were stored (90 days) and thermo-cycled (12,000 x) during this period (90 d/TC) before testing. A shear bond strength (SBS) test was performed at a crosshead speed of 0.5 mm/min. Two factors composed the experimental design: ceramic conditioning strategy (in four levels) and storage condition (in two levels), totaling eight groups. After 90 d/TC (Tukey; p < 0.05), SiO2 + MDP-primer (24.40 MPa) promoted the highest SBS. The ALC and MDP-primer groups debonded spontaneously during 90 d/TC. Bonding values were higher and more stable in the SiO2 groups. The use of MDP-primer after silica coating increased the bond strength.

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OBJECTIVE: This study evaluated the surface hardness of a resin cement (RelyX ARC) photoactivated through indirect composite resin (Cristobal) disks of different thicknesses using either a light-emitting diode (LED) or quartz tungsten halogen (QTH) light source. MATERIAL AND METHODS: Eighteen resin cement specimens were prepared and divided into 6 groups according to the type of curing unit and the thickness of resin disks interposed between the cement surface and light source. Three indentations (50 g for 15 s) were performed on the top and bottom surface of each specimen and a mean Vickers hardness number (VHN) was calculated for each specimen. The data were analyzed using two-way ANOVA and Tukey-Kramer test was used for post-hoc pairwise comparisons. RESULTS: Increased indirect resin disk thickness resulted in decreased mean VHN values. Mean VHN values for the top surfaces of the resin cement specimens ranged from 23.2 to 46.1 (QTH) and 32.3 to 41.7 (LED). The LED curing light source produced higher hardness values compared to the QTH light source for 2- and 3-mm-thick indirect resin disks. The differences were clinically, but not statistically significant. Increased indirect resin disk thickness also resulted in decreased mean VHN values for the bottom surfaces of the resin cement: 5.8 to 19.1 (QTH) and 7.5 to 32.0 (LED). For the bottom surfaces, a statistically significant interaction was also found between the type of curing light source and the indirect resin disk thickness. CONCLUSION: Mean surface hardness values of resin cement specimens decreased with the increase of indirect resin disk thickness. The LED curing light source generally produced higher surface hardness values.

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OBJECTIVE: This study evaluated the surface hardness of a resin cement (RelyX ARC) photoactivated through indirect composite resin (Cristobal) disks of different thicknesses using either a light-emitting diode (LED) or quartz tungsten halogen (QTH) light source. MATERIAL AND METHODS: Eighteen resin cement specimens were prepared and divided into 6 groups according to the type of curing unit and the thickness of resin disks interposed between the cement surface and light source. Three indentations (50 g for 15 s) were performed on the top and bottom surface of each specimen and a mean Vickers hardness number (VHN) was calculated for each specimen. The data were analyzed using two-way ANOVA and Tukey-Kramer test was used for post-hoc pairwise comparisons. RESULTS: Increased indirect resin disk thickness resulted in decreased mean VHN values. Mean VHN values for the top surfaces of the resin cement specimens ranged from 23.2 to 46.1 (QTH) and 32.3 to 41.7 (LED). The LED curing light source produced higher hardness values compared to the QTH light source for 2- and 3-mm-thick indirect resin disks. The differences were clinically, but not statistically significant. Increased indirect resin disk thickness also resulted in decreased mean VHN values for the bottom surfaces of the resin cement: 5.8 to 19.1 (QTH) and 7.5 to 32.0 (LED). For the bottom surfaces, a statistically significant interaction was also found between the type of curing light source and the indirect resin disk thickness. CONCLUSION: Mean surface hardness values of resin cement specimens decreased with the increase of indirect resin disk thickness. The LED curing light source generally produced higher surface hardness values.

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O objetivo deste trabalho foi avaliar a translucidez de diferentes cores da cerâmica, o grau de conversão de diferentes cores do agente de fixação resinoso e a resistência de união entre a cerâmica e a dentina, variando as cores da cerâmica e do agente de fixação e o tempo de fotoativação. A hipótese é que quanto mais escuros o agente de fixação resinoso e a cerâmica, menor translucidez, menor conversão dos monômeros, mais baixa será a resistência adesiva, portanto maior tempo necessário para fotoativação. Três discos da cerâmica Vita VM7 com dimensão de 20 x 2 mm nas cores Base Dentine 0M1, Base Dentine 2M2 e Base Dentine 5M3 e dois discos com 20 x 2,5 mm da mesma cerâmica nas cores Base Dentine 0M1 e Base Dentine 5M3 foram usados para determinar a percentagem de translucidez através do espectrofotômetro MiniScan. Para se obter o grau de conversão (GC), os cp do agente de fixação (Variolink II; A3 Amarelo e transparente; espessura: 100 μm) foram fotoativados sob um bloco cerâmico (espessura: 2 mm; Base Dentine 0M1, Base Dentine 2M2 e Base Dentine 5M3) por 20 ou 40 s. Cpfotoativados sem o bloco cerâmico foram usados como controle. Dezesseis grupos (n=3) foram avaliados. Espectrometria de Micro-ATR/FTIR foi utilizada para avaliar a extensão da polimerização de todos os cp depois de 24 h. A %GC foi calculada e os dados foram analisados através de ANOVA 1-fator e teste de Tukey ( =0,05). Para avaliar adesão, a dentina da superfície oclusal de 80 molares humanos hígidos foi exposta e condicionada com ácido fosfórico 37% e adesivo (Excite DSC). Oitenta blocos (7,2 x 7,2 x 2,5 mm) da mesma cerâmica, nas cores Base Dentine 0M1 e Base Dentine 5M3, foram confeccionados de acordo com as instruções do fabricante. A superfície cerâmica foi tratada com ácido fluorídrico 10% por 60 s e silanizada. Os blocos cerâmicos de cada cor foram cimentados sobre a dentina tratada usando o agente de fixação de cor A3 Amarelo ou transparente. Os cp foram fotoativados...

The aim of this study was to evaluate the translucency of different ceramics hades, degree of conversion of different resin cement and the bonds trength between a feldspathic ceramic and dentin using different resin cement and ceramic shades, and the activation time. The hypothesis is the darker the resin cement and ceramic, lower the translucency; the lower the degree of monomers conversion, lower the bond strength, then the activation time should be higher. Three discs of Vita VM7 ceramic with 20 x 2 mm and shades: Base Dentine 0M1, Base Dentine 2M2 and Base Dentine 5M3, and two discs with 20 x 2.5 mm of the same ceramic and shades: Base Dentine 0M1 and Base Dentine 5M3 were used to determine the translucency percentage of each sp using the MiniScan espectrophotometer. For measure the degree of conversion (DC), the resin cement (Variolink II; A3 Yellow and transparent) specimens(thickness: 100 μm) were photocured under a ceramic block (2mm-thick;Base Dentine 0M1, Base Dentine 2M2 and Base Dentine 5M3) for 20 or 40 s. Specimen photocured without the ceramic block were used as control. Sixteen groups (n=3) were evaluated. Micro-ATR/FTIR spectrometry was used to evaluate the extent of polymerization of all sp after 24 h. The %DC was calculated and the data were analyzed using ANOVA 1-way and Tukey test ( =0,05). For the microtensile bonds trength test, the occlusal dentin surface of eighty molars were exposed and etched with 37% phosphoric acid and an adhesive (Excite DSC) was applied. Eighty blocks (7.2 x 7.2 x 2.5 mm) of Base Dentine 0M1 and Base Dentine 5M3 of Vita VM7 ceramic were produced according to the manufacturers. The ceramic surface was etched with 10% hydro fluoric acid for 60 s, followed by the application of a silane agent and a dualcured resin cement (Variolink II; base and catalyst: A3 Yellow; base and catalyst: transparent), according to the manufacturers’ recommendations.Ceramic blocks of each shade were...

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Avaliar a influência de diferentes unidadespolimerizadoras na resistência de união ao cisalhamento entrediferentes metais a uma resina laboratorial. Método: Foramconfeccionados 60 cilindros metálicos (5mm x 4mm), sendotrinta em titânio comercialmente puro (Ticp) e trinta em liga deouro-paládio (Au-Pd), jateados (Al2O3 110μm, 20s, 2,9 bar)previamente à aplicação de resina. Foram aplicadas duascamadas do opaco (Sinfony) e posteriormente foi aplicada aresina de revestimento estético Sinfony na superfície deunião ao material estético nos cilindros metálicos. O opaco ea resina de revestimento foram polimerizados em diferentesunidades, de acordo com os grupos experimentais: GrA1-Ticp + Visio Beta (3M ESPE/EUA); GrA2 – Ticp + Powerlux(EDG, Brasil); GrA3 – Ticp + Strobolux (EDG, Brasil); GrB1 –Au-Pd + Visio Beta; GrB2 – Au-Pd + Powerlux; GrB3 – Au-Pd+ Strobolux. As amostras foram submetidas ao cisalhamentoem máquina de teste universal (EMIC/Brasil) com célula decarga com capacidade de 500 Kg (0,5 mm/min). Os dadosobtidos (MPa) foram submetidos à análise de variância ANOVA2 fatores e teste Tukey (5%). Resultados: As médias edesvio-padrão obtidos foram (MPa): GrA1: 6,1±1,9; GrA2:5,6±1,4; GrA3: 5,5±2,5; GrB1:9,46±2,5; GrB2:7,4±2; GrB3:8,2±3,1. Conclusão: As ligas de Au-Pd promovem uma maiorresistência de união à resina indireta Sinfony comparado aoTicp, independente da unidade polimerizadora utilizada...

To evaluate the effect of different polymerizationunits on the shear bond strength between different metalsand a laboratorial resin. Material and Method: Sixty metalliccylinders were obtained (5mm x 4mm), thirty in commerciallypure titanium (CpTi) and thirty in gold-palladium alloy (Au-Pd),which were sandblasted (Al2O3 110μm, 20s, 2,9 bar) beforethe resin application. Two layers of opaque (Sinfony Opaque)were applied with a brush and with the assistance of theteflon matrix, the esthetic veneering resin was applied onthe metallic cylinders. The opaque and veneering resin werepolymerized at different polymerized, according toexperimental groups: GrA1 – CpTi + Visio Beta (3M ESPE/EUA); GrA2 – CpTi + Powerlux (EDG, Brazil); GrA3 – CpTi +Strobolux (EDG, Brasil); GrB1 – Au-Pd + Visio Beta; GrB2 –Au-Pd + Powerlux; GrB3 – Au-Pd + Strobolux. The specimenswere submitted to shear test in a universal testing machine(model DL/1000-EMIC) with a 500kg load cell (0,5 mm/min).The data (MPa) were submitted to the analysis of variance(ANOVA) and tukey’s test (5%). Results: The means andstandard deviations obtained were (MPa): GrA1: 6.1±1.9;GrA2: 5.6±1.4; GrA3: 5.5±2.5; GrB1: 9.4±2.5; GrB2: 7.4±2; GrB3:8.2±3.1. Conclusion: The Au-Pd alloys promote higher bondstrength to sinfony indirect resin compared to Ticp, regardlessthe polymerized unit used...

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Avaliar a influência de diferentes dispositivos decarregamento na resistência de união ao cisalhamento entreo titânio comercialmente puro (Ticp) e uma resina indireta.Materiais e Método: Foram confeccionados trinta cilindrosmetálicos (CM) em Ticp (altura: 5 mm; diâmetro: 4 mm). OsCM tiveram sua superfície adesiva jateada com Al2O3 110 μm.Todos os cilindros foram imersos em álcool isopropílico 10% elimpos em banho ultra-sônico (10 min). Duas camadas(espessura: 0,2 mm) de Sinfony Opaco foram aplicadas sobrea superfície jateada dos CM e submetidas à polimerização nasunidades Visio Alfa e Visio Beta. Com auxílio de um dispositivode teflon, a resina de recobrimento estético Sinfony foi aplicada(altura: 5 mm; diâmetro: 4 mm) sobre a camada de opaco epolimerizada de acordo com as recomendações do fabricante.As amostras foram divididas em três grupos, de acordo com otipo de dispositivo para carregamento utilizado para o ensaiode cisalhamento (n=10): Gr1- pistão, Gr2- cinzel reto e Gr3-cinzel reto com entalhe. As amostras foram submetidas aoensaio de cisalhamento na máquina de ensaio universal. Osdados (MPa) foram submetidos à análise de variância (ANOVA).Resultados: As médias e desvios-padrões obtidos foram: Gr1-5,49±1,41 MPa; Gr2- 5,37±0,8 MPa e Gr3- 5,56±1,92 MPa.Conclusão: Todos os dispositivos testados apresentaramdesempenho semelhante na análise da união metal/resina(p=0,9550>0,05)...

The aim of this study was to evaluate the influenceof the different devices on the shear bond strength betweenthe titanium (Ticp) and an indirect resin. Material and Method:Thirty metallic cylinders of Ticp (height: 5 mm; diameter: 4mm) obtained by machining of pure commercially titaniumbar (Ticp). The metallic cylinders had their adhesive surfacesandblasted (Al2O3; 110μm). All cylinders were immerged inisopropyl alcohol 10% and were cleaned ultrasonically (10min). Two layers of the resin Opaque Sinfony were applied onthe metallic cylinders and cured in the Visio Alfa and VisioBeta units, according to the manufacturer’s recommendation.The esthetic resin Sinfony was applied (height: 5 mm; diameter:4 mm) on the opaque layer using a teflon device, according tothe manufacturer’s instructions. The specimens were dividedinto three groups, according to the shear device used (n=10):Gr1: piston, Gr2: knife without a groove; Gr3: knife with a groove.The shear test was performed in a universal testing machine.Bond strength results were analyzed using one-way ANOVA.Results: The means and standard deviations obtained were:Gr1- 5.49 ± 1.41 MPa, Gr2- 5.37 ± 0.8 MPa and Gr3- 5.56 ±1.92 MPa. Conclusion: All devices used showed similarperformance on the bond strength between metal/resin(p=0.9550>0.05)...

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OBJECTIVES: The aim of this study was to evaluate the intrapulpal temperature variation after bleaching treatment with 35% hydrogen peroxide using different sources of activation. MATERIAL AND METHODS: Twenty-four human teeth were sectioned in the mesiodistal direction providing 48 specimens, and were divided into 4 groups (n=12): (G1) Control - Bleaching gel without light activation, (G2) Bleaching gel + halogen light, (G3) Bleaching gel + LED, (G4) Bleaching gel + Nd:YAG Laser. The temperatures were recorded using a digital thermometer at 4 time points: before bleaching gel application, 1 min after bleaching gel application, during activation of the bleaching gel, and after the bleaching agent turned from a dark-red into a clear gel. Data were analyzed statistically by the Dunnet's test, ANOVA and Tukey's test (a=0.05). RESULTS: The mean intrapulpal temperature values ( degrees C) in the groups were: G1: 0.617 +/- 0.41; G2: 1.800 +/- 0.68; G3: 0.975 +/- 0.51; and G4: 4.325 +/- 1.09. The mean maximum temperature variation (MTV) values were: 1.5 degrees C (G1), 2.9 degrees C (G2), 1.7 degrees C (G3) and 6.9 degrees C (G4). When comparing the experimental groups to the control group, G3 was not statistically different from G1 (p>0.05), but G2 and G4 presented significantly higher (p<0.05) intrapulpal temperatures and MTV. The three experimental groups differed significantly (p<0.05) from each other. CONCLUSIONS: The Nd:YAG laser was the activation method that presented the highest values of intrapulpal temperature variation when compared with LED and halogen light. The group activated by LED light presented the lowest values of temperature variation, which were similar to that of the control group.

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OBJECTIVES: The aim of this study was to evaluate the intrapulpal temperature variation after bleaching treatment with 35 percent hydrogen peroxide using different sources of activation. MATERIAL AND METHODS: Twenty-four human teeth were sectioned in the mesiodistal direction providing 48 specimens, and were divided into 4 groups (n=12): (G1) Control - Bleaching gel without light activation, (G2) Bleaching gel + halogen light, (G3) Bleaching gel + LED, (G4) Bleaching gel + Nd:YAG Laser. The temperatures were recorded using a digital thermometer at 4 time points: before bleaching gel application, 1 min after bleaching gel application, during activation of the bleaching gel, and after the bleaching agent turned from a dark-red into a clear gel. Data were analyzed statistically by the Dunnet's test, ANOVA and Tukey's test (a=0.05). RESULTS: The mean intrapulpal temperature values (ºC) in the groups were: G1: 0.617 ± 0.41; G2: 1.800 ± 0.68; G3: 0.975 ± 0.51; and G4: 4.325 ± 1.09. The mean maximum temperature variation (MTV) values were: 1.5ºC (G1), 2.9ºC (G2), 1.7ºC (G3) and 6.9ºC (G4). When comparing the experimental groups to the control group, G3 was not statistically different from G1 (p>0.05), but G2 and G4 presented significantly higher (p<0.05) intrapulpal temperatures and MTV. The three experimental groups differed significantly (p<0.05) from each other. CONCLUSIONS: The Nd:YAG laser was the activation method that presented the highest values of intrapulpal temperature variation when compared with LED and halogen light. The group activated by LED light presented the lowest values of temperature variation, which were similar to that of the control group.

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OBJECTIVES: To evaluate the microtensile bond strength (µTBS) of one- (Xeno III, Dentsply) and two-step (Tyrian-One Step Plus, Bisco) self-etching adhesive systems bonded to dentin and cemented to chemically cured (C&B Metabond) or light-cured paste of a dual-cure resin cement (Variolink II, Ivoclar) within a short (24 h) and long period of evaluation (90 days). MATERIAL AND METHODS: Forty recently extracted human molars had their roots removed and their occlusal dentin exposed and ground wet with 600-grit SiC paper. After application of one of the adhesives, the resin cement was applied to the bonded surface and a composite resin block was incrementally built up to a height of 5 mm (n=10). The restored teeth were stored in distilled water at 37ºC for 7 days. The teeth were then cut along two axes (x and y), producing beam-shaped specimens with 0.8 mm² cross-sectional area, which were subjected to µTBS testing at a crosshead speed of 0.05 mm/min and stressed to failure after 24 h or 90 days of storage in water. The µTBS data in MPa were subjected to three-way analysis of variance and Tukey's test (α= 0.05). RESULTS: The interaction effect for all three factors was statistically significant (three-way ANOVA, p<0.001). All eight experimental means (MPa) were compared by the Tukey's test (p<0.05) and the following results were obtained: Tyrian-One Step Plus /C&B/24 h (22.4±7.3); Tyrian-One Step Plus /Variolink II/24 h (39.4±11.6); Xeno III/C&B/24 h (40.3±12.9); Xeno III/Variolink II/24 h (25.8±10.5); Tyrian-One Step Plus /C&B/90 d (22.1±12.8) Tyrian-One Step Plus/VariolinkII/90 d (24.2±14.2); Xeno III/C&B/90 d (27.0±13.5); Xeno III/Variolink II/90 d (33.0±8.9). CONCLUSIONS: Xeno III/Variolink II was the luting agent/adhesive combination that provided the most promising bond strength after 90 days of storage in water.

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OBJECTIVES: To evaluate the microtensile bond strength (microTBS) of one- (Xeno III, Dentsply) and two-step (Tyrian-One Step Plus, Bisco) self-etching adhesive systems bonded to dentin and cemented to chemically cured (C&B Metabond) or light-cured paste of a dual-cure resin cement (Variolink II, Ivoclar) within a short (24 h) and long period of evaluation (90 days). MATERIAL AND METHODS: Forty recently extracted human molars had their roots removed and their occlusal dentin exposed and ground wet with 600-grit SiC paper. After application of one of the adhesives, the resin cement was applied to the bonded surface and a composite resin block was incrementally built up to a height of 5 mm (n=10). The restored teeth were stored in distilled water at 37 degrees C for 7 days. The teeth were then cut along two axes (x and y), producing beam-shaped specimens with 0.8 mm(2) cross-sectional area, which were subjected to microTBS testing at a crosshead speed of 0.05 mm/min and stressed to failure after 24 h or 90 days of storage in water. The microTBS data in MPa were subjected to three-way analysis of variance and Tukey's test (alpha= 0.05). RESULTS: The interaction effect for all three factors was statistically significant (three-way ANOVA, p<0.001). All eight experimental means (MPa) were compared by the Tukey's test (p<0.05) and the following results were obtained: Tyrian-One Step Plus /C&B/24 h (22.4+/-7.3); Tyrian-One Step Plus /Variolink II/24 h (39.4+/-11.6); Xeno III/C&B/24 h (40.3+/-12.9); Xeno III/Variolink II/24 h (25.8+/-10.5); Tyrian-One Step Plus /C&B/90 d (22.1+/-12.8) Tyrian-One Step Plus/VariolinkII/90 d (24.2+/-14.2); Xeno III/C&B/90 d (27.0+/-13.5); Xeno III/Variolink II/90 d (33.0+/-8.9). CONCLUSIONS: Xeno III/Variolink II was the luting agent/adhesive combination that provided the most promising bond strength after 90 days of storage in water.

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O trauma oclusal é causado pela força oclusal excessiva e muitas vezes está associado com a perda do osso alveolar. Na presença de trauma oclusal, periodontites provocadas por biofilme estão sujeitas a ter uma evolução mais rápida que periodontites onde o trauma oclusal não está associado. Nesta revisão foi detalhada a atuação de duas proteínas (osteopontina e RANKL) que podem estar envolvidas neste processo. Sabe-se que a osteopontina é uma proteína produzida sob carga mecânica e induz a migração dos osteoclastos para o local da reabsorção. O receptor ativador do fator nuclear Kappa B (RANKL) é um importante fator na diferenciação, ativação e sobrevivência dos osteoclastos, e participa da indução in vitro da osteopontina intracelular. Entretanto, o envolvimento do RANKL na reabsorção óssea inflamatória, com ou sem trauma oclusal, e o papel da osteopontina nas células ainda não está claro. No presente estudo, uma revisão de literatura foi realizada com o objetivo de elucidar a imunohistoquímica do trauma oclusal associado aos tecidos periodontais, enfatizando a atuação da osteopontina e do RANKL, assim como a relação entre o trauma oclusal e os tecidos periodontais. Com base no que existe atualmente na literatura, o mecanismo preciso de degradação periodontal sob excessiva carga oclusal ainda não está bem estabelecido em virtude da complexa ação das referidas proteínas.

The occlusal trauma is caused by excessive occlusal loading and many times are associated with the anatomy ofthe osseous structures. In the presence of occlusal loading, periodontitis caused for bacterial film could be an evolution faster than periodontitis disease where the occlusal trauma is not associated. In this review, it will be emphasized the action of two proteins (osteopontin and RANKL) that can be involved in this process. The osteopontin is known to be reduced upon mechanical loading and is considered to induce migration of osteoclasts to the resorption bone. The receptor activator of nuclear factor Kappa B (RANKL) is an important factor in the differentiation, activation and survival of the osteoclasts, and participates of the induction in vitro of the intracellular osteopontin. However, the evolvement of the RANKL in the inflammatory osseous resorption, with or without oclusal loading, and the function of the osteopontin in the cells is unclear. In the present study, a literature review was carried through with the objective to elucidate the immunohistochemistry of the occlusal trauma associate to the periodontal tissues, emphasizing the action of osteopontin and RANKL, as well as the relation between the occlusal loading and periodontal tissues. On the basis of what it exists currently in literature, the necessary mechanism of the fabric periodontal under excessive occlusal loading was unclear because of the complex action of these proteins.

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