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1.
Braz. oral res. (Online) ; 36: e093, 2022. tab, graf
Article in English | LILACS-Express | LILACS, BBO | ID: biblio-1384196

ABSTRACT

Abstract: The aim of the study was to evaluate how the association of solvents (tetrahydrofuran [THF], dimethyl sulfoxide [DMSO], ethanol [ET] or acetone [ACT]) with experimental dental adhesives affects selected properties of experimental dental adhesives and dentin bond durability. Six adhesive combinations were prepared containing: 30 % ET, 30 % ACT, 30 % THF, 28 % ET + 2 % DMSO (ET+DMSO), 15 % ethanol + 15 % THF (ET+THF), or 28 % THF + 2 % DMSO (THF+DMSO). Thirty-six molars (n = 6) were cut to expose the coronary dentin, and were randomly divided according to the adhesives. They were restored, and then cut into resindentin sticks (1 mm²), and stored in distilled water for 24 h or 6 months, until conducting the microtensile bond strength and nanoleakage tests. Other experiments performed with adhesives included viscosity assessment using a rheometer, and degree of conversion using Fourier-transform infrared spectroscopy (FTIR). The data were analyzed statistically using two-way ANOVA and Tukey's test (p < 0.05). The adhesive formulated exclusively with THF showed the highest viscosity, followed by ET+THF, which obtained the highest degree of conversion compared to ET, and THF alone. ET+DMSO obtained the highest 24-h and aged bond strengths (p < 0.05). ET+THF increased the nanoleakage slightly after 6 months, but attained the only gap-free adhesive interface among all the groups. The combination of alternative solvents, particularly THF, with conventional ones (ET) has improved chemical properties, and the dentin bonding of experimental simplified adhesives.

2.
Braz. dent. j ; 32(3): 92-104, May-June 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1345500

ABSTRACT

Abstract This in vitro study evaluated the effect of the beam homogeneity of a multiple-peak light-curing unit on the surface microhardness and the effect of toothbrushing wear on the microhardness, surface roughness, roughness profile, volume loss, and gloss retention of incremental and bulk-fill resin-based composites (RBCs). A LED light-curing unit (VALO) with four LEDs at the tip end (405, 445, 465A, and 465B nm emission peak) was used according to each manufacturer-recommended time to obtain disks (n=10) of six RBCs: Estelite Sigma Quick, Charisma Classic, Tetric EvoCeram Bulk Fill, Filtek Z250, Filtek Supreme Ultra, and Filtek Bulk Fill. Microhardness values were obtained according to each LED positioning of the light-curing unit on the top surface of the RBCs and were analyzed before and after toothbrushing regarding microhardness, surface roughness, roughness profile, volume loss, and gloss retention. Microhardness was considered homogeneous on the top surface regardless of the type of RBC or wavelength tested (p>0.05). Overall, toothbrushing did not reduce the microhardness of the RBCs but influenced the gloss values for most RBCs (p<0.001). Charisma Classic presented the greatest surface roughness and roughness profile after toothbrushing (p<0.05). Volume loss did not differ among RBCs (p>0.05). In conclusion, different wavelengths of the LED did not affect the top surface microhardness, regardless of the RBCs tested; and bulk-fill composites presented similar surface changes (microhardness, surface roughness, roughness profile, volume loss, and gloss retention) when compared to conventional composites after toothbrushing.


Resumo Este estudo in vitro avaliou a homogeneidade do feixe de um fotopolimerizador de múltiplos picos na microdureza superficial e o efeito da escovação na microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e retenção do brilho de compósitos a base de resina (RBCs) incrementais ou bulk-fill. Um fotopolimerizador LED (VALO) com quatro LEDs na ponteira (405, 445, 465A e 465B nm de pico de emissão) foi usado de acordo com o tempo recomendado por cada fabricante para obtenção de discos (n=10) de seis RBCs: Estelite Sigma Quick, Charisma Classic, Tetric EvoCeram Bulk Fill, Filtek Z250, Filtek Supreme Ultra e Filtek Bulk Fill. Os valores de microdureza foram obtidos seguindo o posicionamento de cada LED na superfície superior das amostras e foram analisados antes e após a escovação quanto a microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e retenção do brilho. A microdureza foi considerada homogênea no topo da superfície, independentemente do tipo de RBCs ou comprimento de onda testados (p>0.05). No geral, a escovação não reduziu a microdureza das RBCs, mas influenciou o brilho para a maioria das RBCs (p<0.001). Charisma Classic apresentou os maiores valores de rugosidade superficial e perfil de rugosidade após a escovação (p<0.05). A perda de volume não diferiu entre as RBCs (p>0.05). Em conclusão, os diferentes comprimentos de onda do LED não alteraram a microdureza do topo da superfície, independentemente das RBCs testadas; e as resinas bulk-fill apresentaram alterações superficiais similares (microdureza, rugosidade superficial, perfil de rugosidade, perda de volume e manutenção do brilho) quando comparadas às resinas convencionais após a escovação.


Subject(s)
Composite Resins , Dental Materials , Surface Properties , Materials Testing , Polymerization
3.
Braz. dent. sci ; 24(4, suppl 1): 1-9, 2021. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1352595

ABSTRACT

Objective: The aim of this study was to evaluate the microshear bond strength of Universal adhesives to enamel and dentin after one week and eighteen months of water storage. Material and Methods: Fragments from the buccal surfaces of 80 bovine teeth were prepared (12x5x1.0 mm) and ground to obtain flat surfaces of enamel and dentin. Samples were randomly assigned to 8 experimental groups (n=10), according to four adhesive systems (Adper Single Bond Plus/control ­ not a Universal adhesive/ASB; Ambar Universal/AUN; Prime&Bond Active/PBA and Scotchbond Universal/SBU) and two water-storage times (one week and eighteen months after sample preparations). Adhesives were applied according to the manufacturers' instructions and molds were positioned over bonded surfaces. A flowable composite was poured into the molds to fill up their internal diameter and obtain resin cylinder (1.0mm height/0.7mm internal diameter) after light-curing. Bond strength was determined using a testing machine (0.5 mm/min) and data were statistically analyzed by two-way analysis of variance (ANOVA) and the post-hoc Tukey's test (alpha=0.05). Failure patterns were analyzed for all resin cylinder tested. Results: For enamel, differences among adhesives were observed only at 18 months, in which SBU produced lower bond strength values (15.9±3.0 MPa) than the others universal adhesives (AUN: 19.3±4.8 and PBA: 21.4±2.1 MPa) (p<0.05). For dentin, there were differences among adhesives only at 7 days, with PBA showing the highest bond strength (37.4±4.9 MPa) and ASB the lowest one (19.4±3.9 MPa) (p<0.05). Enamel and dentin bond strength of all adhesives decreased significantly after 18 months and reduction percentage varied from 36.9 to 52.4 for enamel and from 35.1 to 62.8 for dentin. Adhesive and mixed failures showed high incidences. Conclusion: Results suggested that adhesives presented differences among them depending on type of hard dental tissue and evaluation time. Enamel and dentin bond strengths of control and all universal adhesives tested were not stable, decreasing at eighteen months. (AU)


Objetivo: O objetivo deste estudo foi avaliar a resistência de união ao microcisalhamento de adesivos universais ao esmalte e dentina após uma semana e dezoito meses de armazenamento em água. Material e Métodos: Fragmentos da superfície vestibular de 80 dentes bovinos foram preparados (12x5x1,0 mm) até o obtenção de superfícies planas de esmalte e dentina. As amostras foram distribuídas aleatoriamente em 8 grupos experimentais (n=10), de acordo com quatro sistemas adesivos (Adper Single Bond Plus / controle - não universal; Ambar Universal; Prime & Bond Active e Scotchbond Universal) e dois tempos de armazenamento em água (uma semana e dezoito meses após o preparo das amostras). Os adesivos foram aplicados de acordo com as instruções dos fabricantes e as matrizes foram posicionadas sobre as superfícies aderidas. Um compósito fluido foi aplicado nas matrizes para preencher seu diâmetro interno e obter o cilindro do compósito por fotopolimeração (1,0 mm de altura / 0,7 mm de diâmetro interno). A resistência de união foi determinada em uma máquina universal de ensaios (0,5mm/min). Os dados foram analisados estatisticamente pela análise de variância dois fatores (ANOVA) e teste de Tukey (alfa 0,05). Resultados: Para o esmalte, foram obtidas diferenças apenas aos 18 meses, em que Scotchbond Universal produziu menor média de resistência de união do que os demais adesivos universais. Para dentina, houve diferenças entre os adesivos apenas aos 7 dias, com o Prime & Bond Active apresentando a maior resistência de união e o Adper Single Bond Plus a menor. Os resultados sugeriram que os adesivos apresentaram diferenças entre si dependendo do substrato e do tempo de avaliação. Conclusão: As resistências de união em esmalte e dentina do controle e de todos os adesivos universais testados não foram estáveis, diminuindo aos dezoito meses (AU)


Subject(s)
Water Storage , Dentin-Bonding Agents , Dental Enamel , Dentin
4.
J. appl. oral sci ; 28: e20190720, 2020. tab, graf
Article in English | LILACS, BBO | ID: biblio-1134776

ABSTRACT

Abstract Objective This study evaluated the clinical effect of violet LED light on in-office bleaching used alone or combined with 37% carbamide peroxide (CP) or 35% hydrogen peroxide (HP). Methodology A total of 100 patients were divided into five groups (n=20): LED, LED/CP, CP, LED/HP and HP. Colorimetric evaluation was performed using a spectrophotometer (ΔE, ΔL, Δa, Δb) and a visual shade guide (ΔSGU). Calcium (Ca)/phosphorous (P) ratio was quantified in the enamel microbiopsies. Measurements were performed at baseline (T 0 ), after bleaching (T B ) and in the 14-day follow-up (T 14 ). At each bleaching session, a visual scale determined the absolute risk (AR) and intensity of tooth sensitivity (TS). Data were evaluated by one-way (ΔE, Δa, ΔL, Δb), two-way repeated measures ANOVA (Ca/P ratio), and Tukey post-hoc tests. ΔSGU and TS were evaluated by Kruskal-Wallis and Mann-Whitney, and AR by Chi-Squared tests (a=5%). Results LED produced the lowest ΔE (p<0.05), but LED/HP promoted greater ΔE, ΔSGU and Δb (T 14 ) than HP (p<0.05). No differences were observed in ΔE and ΔSGU for LED/CP and HP groups (p>0.05). ΔL and Δa were not influenced by LED activation. After bleaching, LED/CP exhibited greater Δb than CP (p>0.05), but no differences were found between these groups at T 14 (p>0.05). LED treatment promoted the lowest risk of TS (16%), while HP promoted the highest (94.4%) (p<0.05). No statistical differences of risk of TS were found for CP (44%), LED/CP (61%) and LED/HP (88%) groups (p>0.05). No differences were found in enamel Ca/P ratio among treatments, regardless of evaluation times. Conclusions Violet LED alone produced the lowest bleaching effect, but enhanced HP bleaching results. Patients treated with LED/CP reached the same efficacy of HP, with reduced risk and intensity of tooth sensitivity and none of the bleaching protocols adversely affected enamel mineral content.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Phototherapy/methods , Tooth Bleaching/methods , Tooth Bleaching Agents/administration & dosage , Carbamide Peroxide/administration & dosage , Hydrogen Peroxide/administration & dosage , Light , Reference Values , Spectrophotometry , Surface Properties/drug effects , Surface Properties/radiation effects , Risk Factors , Analysis of Variance , Treatment Outcome , Colorimetry , Combined Modality Therapy , Statistics, Nonparametric , Dental Enamel/drug effects , Dental Enamel/radiation effects , Dentin Sensitivity/chemically induced
5.
Braz. j. oral sci ; 19: e201602, jan.-dez. 2020. ilus
Article in English | LILACS, BBO | ID: biblio-1116255

ABSTRACT

Aim: Evaluate the effect of adhesives systems combined with desensitizer agents on the microtensile bond strength (µTBS) of a composite resin to dentin. Methods: Cervical dentin of thirty-two human molars were used to simulate hypersensitivity areas. The teeth were divided into four groups (n=8), according to the type of adhesive system and desensitizer agents. No desensitizer was used in the control (Clearfil SE Bond ­ CS). Two experimental groups were pretreated with either MS Coat Bond (MS) or Biofluorid 12 (BF) immediately prior to bonding with CS. The last group corresponded to Gluma Comfort Bond + Desensitizer (GC) application. After dentin treatments, a composite block was built-up on dentin surface and after 24 hours teeth were serially sectioned to obtain bonded bean specimens. Beams were stored in water for 24 hours or one year. Subsequently, the specimens were submitted to the µTBS test. Data were analyzed by two-way mixed ANOVA and Bonferroni's test (α = 0.05). Results: At 24 hours, there was no significant difference in µTBS among groups. However, at one year, dentin treated with MS or BF demonstrated significantly lower µTBS of CS to dentin compared to control and GC, which kept their µTBS stable. Conclusion: The effect of MS and BF desensitizer agents on the µTBS of CS to dentin did not reduce the µTBS at 24 hours, but it decreases significantly after one year


Subject(s)
Calcium Fluoride , Oxalic Acid , Dentin Sensitivity , Dentin Desensitizing Agents
6.
ROBRAC ; 28(87): 232-239, out./dez. 2019. tab, ilus
Article in Portuguese | LILACS-Express | LILACS | ID: biblio-1096272

ABSTRACT

O objetivo deste trabalho foi avaliar o efeito do plasma atmosférico não-térmico (PANT), sozinho ou associado ao jateamento ou adesivo, e do tempo de armazenamento em água na resistência de união por cisalhamento (RUC) do reparo de cerâmicas CAD/CAM de matriz resinosa (CMR) com resina composta. Amostras de 14x7x1mm de três CMRs, Enamic (VITA Zahnfabrik), Cerasmart (GC Corp.) e Lava Ultimate (3M Oral Care), foram obtidas e submetidas ao envelhecimento artificial (EQ-UV, Equilam) por 300 horas. Os seguintes tratamentos de superfície foram realizados: (1- Controle) jateamento + silano + adesivo; (2) PANT; (3) PANT + adesivo; (4) jateamento + PANT. Cilindros de resina composta (Spectra Smart, Dentsply Sirona, 1,5 mm diâmetro e altura) foram aderidos às superfícies tratadas e a RUC foi avaliada em uma máquina de ensaio universal (EZ Test, Shimadzu) após 24 horas ou 1 ano de imersão em água, a 37oC (n=10). No geral, o tratamento controle obteve os melhores resultados de RUC, comparado aos grupos tratados com PANT. Houve redução da RUC após 1 ano de imersão em água para a maioria dos grupos, entre eles para o controle do Enamic e Lava Ultimate, enquanto Cerasmart não mostrou redução. O tratamento com PANT, sozinho ou associado a outro tratamento, não foi capaz de aumentar a RUC do reparo das CMRs com resina composta. O tratamento controle parece ser o melhor método de reparo das CMRs, principalmente considerando-se a longevidade do tratamento.


The objective of this study was to evaluate the effect of nonthermal atmospheric plasma (NTAP), alone or combined with sandblasting or adhesive, and water-storage time on the shear bond strength (SBS) of resin composite repair of resin matrix ceramics (RMC). Samples (14x7x1mm) of three RMCs, Enamic (VITA Zahnfabrik), Cerasmart (GC Corp.), and Lava Ultimate (3M Oral Care), were prepared and submitted to artificial aging (EQ-UV, Equilam) for 300 h. The following surface treatments were performed: (1- Control) sandblasting + silane + adhesive; (2) NTAP; (3) NTAP + adhesive; (4) sandblasting + NTAP. Resin composite cylinders (Spectra Smart, Dentsply Sirona, 1,5 mm diameter and height) were bonded to the treated surfaces and the SBS was evaluated in a universal testing machine (EZ Test, Shimadzu) after 24 h or 1 year of water storage, at 37oC (n=10). In general, the control treatment obtained the best SBS results, compared to groups treated with NTAP. There was a decrease in SBS after 1 year of water immersion for most groups, including the control treatment for Enamic and Lava Ultimate, while Cerasmart presented no reduction. The treatment with NTAP alone or combined with another treatment, was not capable of increasing the SBS of resin composite repair to RMCs. Control treatment seems to be the best method for repairing CMRs, mainly considering the treatment longevity.

7.
Braz. dent. sci ; 22(2): 275-280, 2019. tab
Article in English | LILACS, BBO | ID: biblio-997492

ABSTRACT

Objective: to evaluate the effect of aluminum oxide sandblasting (AOS), argon plasma application (APL) and their combination (AOS+APL) on the shear bond strength (SBS) of dual-cure resin cement (Panavia F 2.0, Kuraray Noritake) to two zirconia-based ceramics (Lava, 3M ESPE and Katana, Kuraray Noritake). Material and Methods: One hundred twenty zirconia plates (13 mm in length X 5 mm in width X 1 mm in thickness) were prepared and treated according to the following treatments: 1- AOS, 2- APL,3- AOS+APL and 4- no treatment (control). After treatments, resin cement cylinders (1.4 mm in diameter x 1 mm in height) bonded to zirconia surface were obtained by filling up the silicon matrix. The shear bond test was performed following storage of the samples for 24 hours and one year. Bond strength values were recorded in MPa and the data were analyzed by three-way ANOVA and Tukey post-hoc test (preset alpha of 0.05). Results: In general, AOS and AOS +APL showed the higher SBS. After one-year storage, SBS of the resin cement to the Katana zirconia did not reduce, regardless of the zirconia surface treatment. Conclusion: AOS alone was able to increase the SBS of the resin cement to both zirconia ceramics compared to control and SBS remained stable after one year depending on type of zirconia ceramic. (AU)


Objetivo: avaliar o efeito do jateamento de óxido de alumínio (AOS), aplicação de plasma de argônio (APL) e sua combinação (AOS + APL) na resistência ao cisalhamento (SBS) do cimento resinoso dual (Panavia F 2.0, Kuraray Noritake) a duas cerâmicas à base de zircônia (Lava, 3M ESPE e Katana, Kuraray Noritake). Material e Métodos: Cento e vinte placas de zircônia (13 mm de comprimento X 5 mm de largura X 1 mm de espessura) foram preparadas e tratadas de acordo com os seguintes tratamentos: 1- AOS, 2- APL, 3- AOS + APL e 4 - sem tratamento (controle). Após realizados os tratamentos, com a utilização de uma matriz de silicone (1,4 mm de diâmetro x 1 mm de altura) foram confeccionados cílindros de cimento resinoso na superfície da zircônia. O teste de cisalhamento foi realizado após o armazenamento das amostras por 24 horas e um ano. Os valores de resistência de união foram registrados em MPa e os dados foram analisados por ANOVA de três fatores e teste post-hoc de Tukey (alfa de 0,05). Resultados: Em geral, AOS e AOS + APL apresentaram a maior SBS. Após um ano de armazenamento, o SBS do cimento resinoso para a zircônia Katana não reduziu, independentemente do tratamento da superfície da zircônia. Conclusão: AOS isoladamente foi capaz de aumentar a SBS do cimento resinoso para ambas as zircônias em comparação com o controle e a SBS permaneceu estável após um ano, dependendo do tipo de zircônia. (AU)


Subject(s)
Ceramics , Air Abrasion, Dental , Shear Strength , Plasma Gases
8.
Braz. dent. j ; 29(3): 282-289, May-June 2018. graf
Article in English | LILACS | ID: biblio-951554

ABSTRACT

Abstract The combination of the restoration location, the hand preference of the operator using the light-curing unit (LCU), and the design of the LCU all can have an impact on the amount of the light delivered to the restoration. To evaluate the effect of left-handed or right-handed users, the position of the operator (dentist or assistant), and the LCU design on the irradiance, radiant exposure and emission spectrum delivered to the same posterior tooth. Two light emitting diode (LED) LCUs were tested: an angulated monowave LCU Radii-Cal (SDI, Victoria, Australia) and a straight aligned multi-peak LCU Valo Cordless (Ultradent, South Jordan, UT, USA). The irradiance values (mW/cm2), radiant exposure (J/cm2) and emission spectrum were measured using a sensor in maxillary left second molar tooth. The irradiance and radiant exposure were analyzed using three-way ANOVA followed by Tukey test (a=0.05). The emission spectra (nm) were analyzed descriptively. The interaction between LCU design, operator position, and hand preference significantly influenced the irradiance and radiant exposure (P<0.001). In all cases, Valo delivered significantly higher irradiance than Radii-Cal. The handedness and the operator position affected the irradiance and radiant exposure delivered from Valo. Operator position and access affect the irradiance and radiant exposure delivered to the maxillary left second molar. The irradiance and radiant exposure can be greater when a right-hand operator is positioned on the right side of the chair and a left-hand operator is positioned on the left side of the chair. This may result in better resin composite polymerization.


Resumo A combinação da localização da restauração, a preferência de mão do operador ao utilizar aparelhos fotopolimerizadores (AFP) com luz emitida por diodo (LED) e o formato do AFP podem afetar a quantidade de luz fornecida à restauração. O objetivo foi avaliar o efeito de operadores canhotos e destros, a posição do operador (dentista ou auxiliar), e o formato do AFP na irradiância, energia radiante e espectro de luz entregue ao mesmo dente posterior. Dois AFP foram testados: um com formato angulado, onda única Radii-Cal (SDI, Victoria, Australia) e um formato reto multi-pico Valo Cordless (Ultradent, South Jordan, UT, USA). Os valores de irradiância (mW/cm²), energia radiante (J/cm²) e espectro de luz foram medidos utilizando um sensor no segundo molar superior esquerdo. A irradiância e energia radiante foram analisados utilizando ANOVA 3 fatores seguido por teste de Tukey (a=0.05). O espectro de luz (nm) foi analisado de forma descritiva. A interação entre o formato do AFP, posição do operador e preferência de mão foram significativamente influentes na irradiância e energia radiante (P<0.001). Em todos os casos, Valo teve irradiância significativamente maior que Radii-Cal. A mão dominante e a posição do operador afetaram a irradiância e energia radiante com o Valo. Posição do operador e acesso afetou a irradiância e exposição radiante entregue ao segundo molar superior esquerdo. A irradiância e exposição radiante teve melhores resultados quando AFP foi utilizado com a mão direita pelo operador posicionado na cadeira do lado direito e mão esquerda do operador posicionado do lado esquerdo da cadeira. Estes resultados podem levar a uma melhor polimerização da resina composta.


Subject(s)
Humans , Radiation Exposure , Dental Assistants , Curing Lights, Dental , Functional Laterality , Light , Equipment Design
9.
Braz. oral res. (Online) ; 32: e80, 2018. tab, graf
Article in English | LILACS | ID: biblio-952139

ABSTRACT

Abstract The objective of this study was to investigate microtensile bond strength (MTBS) and interfacial adaptation (IA) of bulk-fill restorative systems bonded to dentin in Class-I-preparations. Box-shaped preparations (4-mm-long, 3-mm-wide, 2-mm-high) made in extracted molars, and Teflon matrix with the same dimensions positioned over the occlusal surface were restored, providing a total of 4-mm composite depth using three bulk-fill restorative systems: Tetric EvoCeram Bulk Fill with Tetric N-Bond (TEC/TNB), SureFil SDR Flow with XP Bond (SDR/XPB) and Filtek Bulk Fill Flowable Restorative with Scotchbond Universal (FBF/SBU); or incrementally restored with a conventional restorative system: Herculite Classic with OptiBond FL (HER/OBF). The specimens were sectioned into beams and the MTBS measured after 24-hours or one-year storage. For evaluation of IA, round-tapered tooth preparations (3-mm-diameter, 1.5-mm-deep) were made, restored with each material and their cross-sectional images were obtained after 24-hours using optical coherence tomography (OCT). The gap percentage for each restoration system was calculated using image analysis software. MTBS for both storage periods: HER/OBF=TEC/TNB=SDR/XPB>FBF/SBU (ANOVA, Tukey's post-hoc, P<0.05) differed significantly among groups, which values were significantly reduced after one-year. SDR/XPB showed comparatively lesser gap formation at the tooth-interface after 24 hours (ANOVA, Dunnett's T3 post-hoc, P<0.05). For deeper restorations, bond strength of TEC/TNB and SDR/XPB can be equal to that of HER/OBF after 24-hours and one-year; however, in a shallower preparation, SDR/XPB showed greater initial interfacial adaptation.


Subject(s)
Humans , Dental Bonding/methods , Dentin-Bonding Agents/chemistry , Dental Marginal Adaptation , Composite Resins/chemistry , Resin Cements/chemistry , Dentin/drug effects , Surface Properties , Tensile Strength , Time Factors , Materials Testing , Reproducibility of Results , Analysis of Variance , Microscopy, Confocal , Dental Restoration Failure , Tomography, Optical Coherence
10.
Braz. j. oral sci ; 16: e17057, jan.-dez. 2017. ilus
Article in English | LILACS, BBO | ID: biblio-883683

ABSTRACT

To evaluate the bond strength of composite resin containing or not biomaterial (S-PRG) to sound/eroded dentine. Methods: Occlusal dentin of 30 human molars (n=15) had half of its surface kept uneroded, while on the other half an erosive lesion was produced by cycling in citric acid (pH 2.3) and supersaturated solution (pH 7.0). On both eroded (ED) and non-eroded (SD) substrates, two restorative systems (containing or not S-PRG) were tested. Composite resin cylinders were built and, after storage in water (24h), were submitted to bond strength test. The analysis of the fracture pattern was performed under an optical microscope (40x). The obtained values of bond strength (MPa) were submitted to ANOVA (two factors) and Tukey multiple comparisons tests (p<0.05). Results: According to the results, there was difference between substrates (<0.001) and restorative materials (p=0.002) evaluated. For the microtensile bond strength, the values obtained were: SDNB (47.6±12.2 MPa), SDWB (34.1±15.8 MPa), EDNB (31.1±8.3 MPa) and EDWB (15.5±13.6 MPa), revealing a statistically significant difference in the evaluated substrates and restorative materials. Conclusion: Bond strength of eroded substrate is inferior to the sound substrate and the restorative system containing S-PRG biomaterial influences negatively the results of bonding to sound/eroded dentin (AU)


Subject(s)
Humans , Male , Female , Composite Resins , Dentin , Tooth Erosion
11.
Braz. dent. j ; 28(6): 731-737, Nov.-Dec. 2017. tab
Article in English | LILACS | ID: biblio-888704

ABSTRACT

Abstract This study evaluated the effect of dentin biomodification on the bond strength (BS) and sealing ability (SA) of HEMA-free and multi-mode adhesives after 24 h and 6 months of water storage. Four adhesives were tested: two multi-mode (Scotchbond Universal - SU, and Prime & Bond Elect - PB) and two HEMA-free (All-Bond 3 - AB, and G-Aenial - GA). Human third molars were selected and dentin was treated with two cross-linking agents (5% glutaraldehyde and 6.5% proanthocyanidin-rich grape seed extract - PACs) for 10 min or kept untreated (control group) (n=6). Teeth were sectioned and prepared for BS test and SA analysis. The SA measurements were taken with the presence of smear layer (minimum permeability), EDTA treatment (maximum permeability), PACs application, adhesive application and after 6 months of water storage. BS data were analyzed by Proc Mixed and Tukey-Kramer test (α=5%). PACs application increased the BS for all adhesives tested at 24 h. However, BS decreased for SU and AB after six months. In general, multi-mode adhesives (SU and PB) did not differ from AB HEMA-free. GA presented the lowest BS values at both times of evaluation. Dentin permeability was reduced after PACs application and remained the same after 6 months, regardless adhesive application. PACs can increase the BS regardless the type of adhesive, however only for PB and GA the BS kept stable after 6-months of water storage. PACs was able to seal the dentin as the minimum permeability and also remained stable after 6 months.


Resumo Este estudo avaliou o efeito da biomodificação da dentina na resistência de união (BS) e capacidade de selamento (SA) de adesivos "HEMA-free" e "multi-mode" após 24 horas e 6 meses de armazenamento em água. Quatro adesivos foram testados: dois "multi-mode" (Scotchbond Universal - SU, e Prime & Bond Elect - PB) e dois "HEMA-free" (All-Bond 3 - AB, e G-Aenial - GA). Terceiros molares humanos foram selecionados e a dentina desses dentes foi tratada com dois agentes "cross-linking" (glutaraldeído 5% e extrato de uva contendo proantocianidina 6.5% - PACs) por 10 min ou permaneceram sem tratamento (grupo controle) (n=6). Os dentes foram seccionados e preparados para teste de BS e análise de SA. As mensurações de SA foram adquiridas com a presença de "smear layer" (mínima permeabilidade), tratamento com EDTA (máxima permeabilidade), aplicação dos PACs, aplicação de adesivo e após 6 meses de armazenamento em água. Os dados de BS foram analisados pelo Proc Mixed e teste de Tukey-Kramer (α=5%). A aplicação dos PACs aumentaram a BS para todos os adesivos testados no tempo de 24 h. Entretanto, a BS reduziu para o adesivo SU e AB após 6 meses. Em geral, os adesivos "multi-mode" (SU e PB) não diferiram do AB "HEMA-free". O adesivo GA apresentou o menor valor de BS em ambos tempos de avaliação. A permeabilidade dentinária foi reduzida após a aplicação dos PACs e permaneceu a mesma até 6 meses, independente da aplicação do adesivo. Os PACs podem aumentar a BS independente do tipo de adesivo, entretanto somente para o adesivos PB e GA a BS manteve estável após 6 meses de armazenamento em água. Os PACs foram capazes de selar a dentina como a permeabilidade mínima da dentina, que permaneceram estável após 6 meses.


Subject(s)
Humans , Dental Cements/chemistry , Dentin/chemistry , Permeability
12.
Braz. oral res. (Online) ; 31(supl.1): e61, Aug. 2017. graf
Article in English | LILACS | ID: biblio-889452

ABSTRACT

Abstract Contemporary dentistry literally cannot be performed without use of resin-based restorative materials. With the success of bonding resin materials to tooth structures, an even wider scope of clinical applications has arisen for these lines of products. Understanding of the basic events occurring in any dental polymerization mechanism, regardless of the mode of activating the process, will allow clinicians to both better appreciate the tremendous improvements that have been made over the years, and will also provide valuable information on differences among strategies manufacturers use to optimize product performance, as well as factors under the control of the clinician, whereby they can influence the long-term outcome of their restorative procedures.


Subject(s)
Curing Lights, Dental , Dental Cements/chemistry , Light-Curing of Dental Adhesives/instrumentation , Light-Curing of Dental Adhesives/methods , Photoinitiators, Dental/chemistry , Polymerization , Absorption, Radiation , Dental Cements/radiation effects , Dental Restoration, Permanent/instrumentation , Dental Restoration, Permanent/methods , Polymerization/radiation effects , Radiation Dosage , Temperature , Time Factors
13.
Braz. dent. j ; 28(3): 362-371, May-June 2017. tab, graf
Article in English | LILACS | ID: biblio-888649

ABSTRACT

Abstract This study measured the radiant power (mW), irradiance (mW/cm2) and emission spectra (mW/cm2/nm) of 22 new, or almost new, light curing units (LCUs): - Alt Lux II, BioLux Standard, Bluephase G2, Curing Light XL 3000, Demetron LC, DX Turbo LED 1200, EC450, EC500, Emitter C, Emitter D, KON-LUX, LED 3M ESPE, Led Lux II, Optilight Color, Optilight Max, Optilux 501, Poly Wireless, Radii cal, Radii plus, TL-01, VALO Cordless. These LCUs were either monowave or multiple peak light emitting diode (LED) units or quartz-tungsten-halogen LCUs used in anterior and posterior teeth. The radiant power emitted by the LCUs was measured by a laboratory grade laser power meter. The tip area (cm²) of the LCUs was measured and used to calculate the irradiance from the measured radiant power source. The MARC-Patient Simulator (MARC-PS) with a laboratory grade spectrometer (USB4000, Ocean Optics) was used to measure the irradiance and emission spectrum from each LCU three times at the sensor located on the facial of the maxillary central incisors and then separately at the occlusal of a maxillary second molar. The minimum acceptable irradiance level was set as 500 mW/cm2. Irradiance data was analyzed using two-way ANOVA and the radiant power data was analyzed by one-way ANOVA followed by Tukey test (a=0.05). In general, the irradiance was reduced at the molar tooth for most LCUs. Only the Valo, Bluephase G2 and Radii Plus delivered an irradiance similar to the anterior and posterior sensors greater than 500 mW/cm2. KON-LUX, Altlux II, Biolux Standard, TL-01, Optilux 501, DX Turbo LED 1200 LCUs delivered lower irradiance values than the recommended one used in molar region, KON-LUX and Altlux II LCUs used at the maxillary incisors. Bluephase G2 and Optilight Max delivered the highest radiant power and KON-LUX, Altlux II and Biolux Standard delivered the lowest power. The emission spectrum from the various monowave LED LCUs varied greatly. The multi-peak LCUs delivered similar emission spectra to both sensors.


Resumo Este estudo mediu a potência (mW), irradiância (mW/cm2) e espectro da luz (mW/cm2/nm) emitida por 22 fontes de luz (Alt Lux II, BioLux Standard, Bluephase G2, Curing Light XL 3000, Demetron LC, DX Turbo LED 1200, EC450, EC500, Emitter C, Emitter D, KON-LUX, LED 3M ESPE, Led Lux II, Optilight Color, Optilight Max, Optilux 501, Poly Wireless, Radii cal, Radii plus, TL-01, VALO Cordless) disponíveis comercialmente. A potência emitida pelas fontes de luz foi medida usando um medidor laboratorial de potencia com grade a laser. A área (cm²) da ponta ativa efetiva das fontes de luz foi medida com paquímetro digital e utilizada para calcular a irradiância emitida. O simulador de paciente-MARC (MARC - PS) com espectrómetro (USB4000, Ocean Optics) foi usado para medir a irradiância e o espectro de luz emitida por cada fonte de luz na região anterior e posterior. Esta medição foi repetida por três vezes em dois sensores localizados na região anterior e posterior da arcada dentária. Os dados de irradiância foram analisados utilizando análise de variância em dois fatores, e os dados de potência foram analisados com análise de variância em fator único seguido pelo teste de Tukey (a=0,05). As fontes de luz Valo, Bluephase G2, Radii Plus emitiram irradiância semelhante tanto na região anterior como posterior com valores superiores ao mínimo de 500 mW/cm2. Seis fontes de luz emitiram irradiância menor que o recomendado (500 mW/cm2) quando usadas na região posterior: Kon-lux, Altlux II, Biolux Standard TL-01, Optilux 501, DX Turbo LED 1200 e duas quando usadas na região anterior: Kon-lux e Altlux II LCUs. As fontes Bluephase G2, Optilight Max emitiram os maiores valores de potência e as fontes de luz Altlux II e Biolux Standard emitiram os menores valores de potência. O espectro de luz das fontes LED de espectro único variou de forma evidente entre as fontes. As fontes LED multi pico de espectro emitiram espectros de luz similar para ambos os sensores. A fotoativação na região posterior tende a reduzir substancialmente a irradiância da maioria das fontes de luzes testadas.


Subject(s)
Humans , Curing Lights, Dental , Dental Restoration, Permanent , Lasers , Patient Simulation , Spectrum Analysis/instrumentation , Tooth/radiation effects
14.
Braz. dent. j ; 28(2): 210-215, mar.-Apr. 2017. tab, graf
Article in English | LILACS | ID: biblio-839140

ABSTRACT

Abstract This study evaluated the effects of three metal primers and one multi-mode adhesive system on the shear bond strength (SBS) of a flowable composite resin to nickel-chrome metal alloy (Ni-Cr). Ninety plates were cast from Ni-Cr and divided in nine groups (n=10). The surfaces were sandblasted with Al2O3 and primed with three adhesive primers: Alloy Primer (AP), Universal Primer (TP) and RelyX Ceramic Primer (CP), and a multi-mode adhesive (Scotchbond Universal, SU). The Adper Single Bond Plus (SB) and SU adhesives were also combined with adhesive primers. Control group did not have any surface treatment. The groups were: AP, AP+SB, AP+SU, TP+SB, TP+SU, CP+SB, CP+SU and SU. Composite cylinders were built on alloy surface. After 24 h, half the specimens were subjected to SBS and the other half to thermal cycling before testing. Data were analyzed by two-way ANOVA and Tukey’s test (a=0.05). Failure modes were assessed by SEM observation. Higher SBS were obtained with AP and TP combined with adhesives at 24 h and the lowest one for control group. Thermocycling reduced SBS for AP, CP+SU and SU. Combination between TP and SU resulted in the highest SBS after the thermocycling. TP groups showed all types of failures and high incidence of mixed failures. The use of AP and UP metal primers before application of SU and SB adhesive systems increased the SBS of composite to Ni-Cr. These combinations between metal primers and adhesives had the highest SBS after thermocycling.


Resumo Este estudo avaliou os efeitos de três primers para metais e um sistema adesivo multi-mode na resistência da união por cisalhamento (SBS) de um compósito resinoso de baixa viscosidade a uma liga niquel-cromo (Ni-Cr). Noventa placas Ni-Cr foram divididas em 9 grupos (n=10). As superfícies foram jateadas com Al2O3 e condicionadas com três primers adesivos: Alloy Primer (AP), Universal Primer (TP) e Rely X Ceramic Primer (CP) e um adesivo multi-mode (Scotchbond Universal, SU). Os adesivos Adper Single Bond Plus (SB) e SU foram combinados com os primers para metais. O grupo controle não recebeu nenhum tipo de tratamento superficial. Os grupos foram: AP, AP+SB, AP+SU, TP+SB, TP+SU, CP+SB, CP+SU e SU. Cilindros de resina foram construídos na superfície da liga. Após 24 h, metade dos espécimes foi submetido ao SBS, a outra metade foi termociclada previamente. Os dados foram analisados pelos testes ANOVA dois fatores e Tukey (a=0.05). Os tipos de fraturas foram determinados utilizando microscopia eletrônica de varredura (MEV). Os maiores valores de SBS foram obtidos com AP e TP combinados com adesivos após 24 h e o menor valor foi obtido no grupo controle. A ciclagem térmica reduziu a SBS para AP, CP+SU e SU. Combinação entre TP e SU resultou em altos valores de SBS após termociclagem. Os grupos TP apresentaram todos os modos de fratura e alta incidência de fraturas mistas. O uso dos primers AP e UP para metais antes da aplicação dos sistemas adesivos SU e SB aumentou a SBS entre o Ni-Cr e a resina composta. Essa combinação entre primers e adesivos mostrou os maiores valores de SBS após a termociclagem.


Subject(s)
Composite Resins/chemistry , Dental Alloys/chemistry , Methacrylates/chemistry , Chromium/chemistry , Materials Testing , Nickel/chemistry
15.
Braz. dent. j ; 28(1): 9-15, Jan.-Feb. 2017. tab, graf
Article in English | LILACS | ID: biblio-839109

ABSTRACT

Abstract The high irradiance and the different emission spectra from contemporary light curing units (LCU) may cause ocular damage. This study evaluated the ability of 15 eye protection filters: 2 glasses, 1 paddle design, and 12 dedicated filters to block out harmful light from a monowave (HP-3M ESPE) and a broad-spectrum (Valo, Ultradent) LED LCU. Using the anterior sensor in the MARC-Patient Simulator (BlueLight Analytics) the irradiance that was delivered through different eye protection filters was measured three times. The LCUs delivered a similar irradiance to the top of the filter. The mean values of the light that passed through the filters as percent of the original irradiance were analyzed using two-way ANOVA followed by Tukey test (a= 0.05). The emission spectra from the LCUs and through the filters were also obtained. Two-way ANOVA showed that the interaction between protective filters and LCUs significantly influenced the amount of light transmitted (p< 0.001). Tukey test showed that the amount of light transmitted through the protective filters when using the HP-3M-ESPE was significantly greater compared to when using the Valo, irrespective of the protective filter tested. When using the HP-3M-ESPE, the Glasses filter allowed significantly more light through, followed by XL 3000, ORTUS, Google Professional, Gnatus filters. The Valo filter was the most effective at blocking out the harmful light. Some protective filters were less effective at blocking the lower wavelengths of light (<420 nm). However, even in the worst scenario, the filters were able to block at least 97% of the irradiance.


Resumo A alta irradiância e diferentes espectros de luz emitidos por aparelhos fotopolimerizadores (Fp) podem causar danos oculares. Este estudo avaliou a capacidade de 15 filtros de proteção ocular em bloquear a luz prejudicial de um Fp convencional (HP-3M ESPE) e outro de largo espectro (Valo, Ultradent). Utilizando sensor anterior do equioamento MARC-Patient Simulator (BlueLight Analytics inc.) a irradiância que passou através dos diferentes filtros protetores foi mensuradas três vezes. Os valores médios da irradiância que passaram pelos filtros foram analisados usando Análise de variância fatorial e pelo teste de Tukey (a= 0.05). O espetro emitido dos Fps através dos filtros também foi obtido. A análise de variância mostrou que a interação entre os filtros protetores e Fps influenciou significantemente a quantidade de luz transmitida (p<0,001). O teste de Tukey mostrou que a quantidade que luz transmitida através dos protetores oculares quando usado o HP-3M ESPE foi significantemente maior quando comparado aos valores para o Valo, independentemente do filtro testado. Quando foi utilizado a fonte de luz HP-3M ESPE, o filtro de proteção ocular permitiu significativamente maior passagem de luz, seguido por XL 3000, ORTUS, Google Professional, e pelo filtro Gnatus. O filtro do Valo foi o mais eficiente ao bloquear a luz prejudicial. Alguns filtros foram menos eficazes ao bloquear menores comprimentos de onde (<420 nm). No entanto, mesmo no pior cenário dos resultados deste estudo, os filtros foram capazes de bloquear ao menos 97% da irradiância emitida pelas fontes de luz testadas.


Subject(s)
Humans , Curing Lights, Dental/adverse effects , Eye Protective Devices/standards , Analysis of Variance , Optics and Photonics
16.
Braz. j. oral sci ; 15(4): 258-263, Oct.-Dec. 2016. ilus
Article in English | LILACS, BBO | ID: biblio-875690

ABSTRACT

Self-adhesive, dual-polymerizing resin cements require no treatment to the prepared tooth surfaces before cementation. Aim: The aim of this study was to evaluate the influence of curing mode on bond strength (BS) of three cementing systems to bovine dentin. Methods: The buccal enamel surfaces of 50 bovine incisors were removed to expose dentin and to flat the surface. The teeth were divided into five groups (n=10), which consisted of two resin cements (Multilink and Clearfil SA Cement) that were tested in dual- (halogen light for 40 s) and self-cured modes, and a control (RelyX ARC). Two cylinders of resin cements (1.0 mm X 0.75 mm) were prepared on each bonded dentin surface. After 24h at 37oC, resin cylinders were subjected to micro-shear testing in a universal testing machine (4411/Instron - 0.5 mm/min). Data were statistically analyzed by two-way ANOVA, Tukey and Dunnett`s test (5%). Results: Multilink showed higher BS than those observed on Clearfil SA. Light-curing resulted in higher BS for both Multilink and Clearfil SA. When Multilink was light-cured, no significant difference on BS was demonstrated between it and RelyX ARC. Conclusions: The highest BS values were obtained in control group and light-cured Multilink resin cement (AU)


Subject(s)
Animals , Cattle , Adhesives , Dentin , Resin Cements , Tensile Strength
17.
Rev. bras. odontol ; 73(2): 96-100, Abr.-Jun. 2016. ilus, tab
Article in Portuguese | LILACS-Express | LILACS | ID: biblio-844010

ABSTRACT

Resumo Objetivo: Este trabalho avaliou o efeito de quatro agentes clareadores na permeabilidade dental. Material e Métodos: Dentes bovinos foram divididos em quatro grupos (n = 10). A permeabilidade inicial dos dentes foi determinada previamente ao clareamento, utilizando equipamento de permeabilidade. Em seguida, foram aplicados os géis clareadores e a permeabilidade novamente mensurada. Os resultados foram expressos em porcentagem de aumento da permeabilidade e os dados submetidos à análise estatística (ANOVA e teste Tukey). Resultados: O Whiteness HP Maxx resultou em maior aumento de permeabilidade (145,7±76,3), quando comparado com Whiteness HP Blue (57,5±36,1) e Pola Office Plus (72,7±19,5). Esses produtos não apresentaram diferença estatística com relação ao Opalescence Boost PF (101,4±46,3). Conclusão: Todos os agentes clareadores testados aumentaram a permeabilidade. A intensidade desse aumento foi dependente do produto utilizado.


Objective: This study evaluated the effect of four bleaching agents on the dental permeability. Material and Methods: Bovine teeth were divided into four groups (n=10), and the initial dental permeability was measured before the bleaching treatments, using a dental hydraulic permeability device. Afterwards, teeth were bleached with whitening products, and the final permeability was recorded. The results were expressed in percentage of increasing permeability (%) and data were submitted to ANOVA and Tukey's test. Results: Whiteness HP Maxx produced higher dental permeability (145.7±76.3) than Whiteness HP Blue (57.5±36.1) and Pola Office Plus (72.7±19.5), which did not differ from Opalescence Boost PF (101.4±46.3). Conclusion: All bleaching agents increased the dental permeability. The increasing intensity was product-dependent.

18.
Braz. j. oral sci ; 14(4): 334-340, Oct.-Dec. 2015. ilus, tab
Article in English | LILACS, BBO | ID: lil-797258

ABSTRACT

Aim: To evaluate the effects of 10% NaOCl gel application on the dentin bond strengths and morphology of resin-dentin interfaces formed by three adhesives. Methods: Two etch-and-rinseadhesives (One-Step Plus, Bisco Inc. and Clearfil Photo Bond, Kuraray Noritake Dental) and oneself-etch adhesive (Clearfil SE Bond, Kuraray Noritake Dental) were applied on dentin accordingto the manufacturers’ instructions or after the treatment with 10% NaOCl (ED-Gel, Kuraray NoritakeDental) for 60 s. For interfacial analysis, specimens were subjected to acid-base challenge andobserved by SEM to identify the formation of the acid-base resistant zone (ABRZ). For microtensilebond strength, the same groups were investigated and the restored teeth were thermocycled(5,000 cycles) or not before testing. Bond strength data were subjected to two-way ANOVA andTukey’s test (p<0.05). Results: NaOCl application affected the bond strengths for One-Step Plusand Clearfil Photo Bond. Thermocycling reduced the bond strengths for Clearfil Photo Bond andClearfil SE Bond when used after NaOCl application and One-Step Plus when used asrecommended by manufacturer. ABRZ was observed adjacent to the hybrid layer for self-etchprimer. The etch-and-rinse systems showed external lesions after acid-base challenge and noABRZ formation when applied according to manufacturer’s instructions. Conclusions:10% NaOClchanged the morphology of the bonding interfaces and its use with etch-&-rinse adhesives reducedthe dentin bond strength. Formation of ABRZ was material-dependent and the interface morphologieswere different among the tested materials.


Subject(s)
Humans , Male , Female , Dental Bonding , Dental Caries Susceptibility , Dentin , Dentin-Bonding Agents , Microscopy, Electron, Scanning , Sodium Hypochlorite
19.
Braz. dent. j ; 26(4): 363-367, July-Aug. 2015. tab, ilus
Article in English | LILACS | ID: lil-756382

ABSTRACT

This study evaluated the effects of indirect restorative materials, curing conditions and time on the degree of conversion (DC) of a dual-cured resin cement using infrared spectroscopy. The resin cement (RelyX Unicem 2, 3M ESPE) was applied to the diamond surface of a horizontal attenuated-total-reflectance unit and activated using one of following conditions: self-cure, direct light exposure, light exposure through indirect restorative materials (resin nano-ceramic: Lava Ultimate, 3M ESPE or feldspathic ceramic: Vita Blocks Mark II, Vita Zahnfabrik). Four thicknesses (0.5, 1.0, 1.5 or 2.0 mm) of each indirect material were analyzed, and the light-activation was performed using a blue LED light. Data (n=5) were analyzed by three-way ANOVA, Tukey's post hoc and Dunnett's tests (α=5%). No significant differences in DC were observed between indirect materials of similar thickness. All groups exhibited higher DC after 10 min than after 5 min. At both times points, the self-cure group exhibited significantly lower DC than all the light exposure groups. Only when the overlying indirect restoration had a thickness of 2 mm did DC decrease significantly. The presence of a thick, indirect restoration can decrease the DC of resin cement. DC after 10 min was higher than after 5 min. The self-cure mode yielded lower DC than the light-activating one.

.

Este estudo avaliou os efeitos do tipo de material restaurador indireto, da condição de ativação e do tempo no grau de conversão de um cimento resinoso de dupla ativação, utilizando espectroscopia de luz infravermelha. O cemento resinoso (RelyX Unicem 2, 3M ESPE) foi aplicado à superfície do diamante da unidade de reflectância atenuada e ativado segundo as seguintes condições: ativação química, exposição direta da luz e aplicação da luz através de dois materiais protéticos: resina nano-cerâmica (Lava Ultimate, 3M ESPE) ou cerâmica feldspática (Vita Blocks Mark II, Vita Zahnfabrik). Quatro espessuras de cada um desses materiais (0,5; 1,0; 1,5 e 2,0 mm) foram analisadas e a ativação realizada com luz LED. Os dados (n=5) foram analisados pela ANOVA três fatores, testes de Tukey e Dunnett (5%). Nenhuma diferença do grau de conversão foi observada entre os materiais. Todos os grupos mostraram maior grau de conversão após 10 min que após 5 min. Em ambos os tempos, o grupo ativado quimicamente teve menor grau de conversão que todos os grupos fotoativados. O grau de conversão foi reduzido somente quando foi utilizada a peça protética de 2 mm. Espessas peças protéticas podem reduzir o grau de conversão do cemento resinoso. A grau de conversão após 10 min é maior que após 5 min da cimentação. A ativação química produz menor grau de conversão que a fotoativação.

.


Subject(s)
Light , Resin Cements/chemistry , Spectroscopy, Fourier Transform Infrared
20.
RSBO (Impr.) ; 12(1): 14-22, Jan.-Mar. 2015. ilus, tab
Article in English | LILACS-Express | LILACS | ID: lil-782781

ABSTRACT

Introduction: The crown preparation promotes the exposure of dentin tubules. Thus, to avoid post-operative sensitivity, the first approach involves the use of dentin adhesives, and the second one the use of dentin desensitizers. Objective: This study evaluated the effect of dentin desensitizers on microtensile bond strengths (μTBSs) of a resin cement to dentin. Material and methods: Twenty bovine teeth were prepared until obtaining flat dentin surfaces. A standardized smear layer was created (#600-grit SiC paper). The samples were randomly divided into the following four groups (n = 5): no treatment (Control), treatment with Gluma Desensitizer (Heraeus Kulzer), Super Seal (Phoenix Dental) and Teethmate Desensitizer (Kuraray Noritake Dental). The dentin surfaces were then treated with ED Primer II (Kuraray Noritake Dental). Twenty composite blocks, 4 mm thick (Estenia CeB, Kuraray Noritake Dental) were used. The composite surfaces were abraded with aluminum oxide (50 μm), and then silanized. The composite block was bonded to the dentin surface with a resin cement (Panavia F 2.0, Kuraray Noritake Dental) according to the manufacturer's instructions. After 24-hour storage (37ºC, 100% RH), the bonded samples were cut into beam-shaped microtensile specimens and loaded in tension until failure. Data were analyzed with one-way ANOVA and the Dunnett's test (α = 0.05). An SEM was used to examine the failure modes. Results: The μTBSs (MPa ± SD) were: 24.4 ± 3.2 (Control), 14.0 ± 5.6 (Gluma Desensitizer), 8.6 ± 4.7 (Super Seal), and 34.7 ± 4.6 (Teethmate Desensitizer), in which there were significant differences among the four groups (p < 0.05). The Teethmate Desensitizer group showed the highest μTBS, while the Super Seal group showed the lowest mean of μTBS to dentin. Conclusion: The efficacy of the desensitizers is material-dependent; Gluma Desensitizer and Super Seal decreased the μTBSs, however, Teethmate Desensitizer improved it.

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