Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 34
Filter
1.
Braz. dent. sci ; 25(4): 1-8, 2022. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1400986

ABSTRACT

Objective: To analyze the wettability on the surface of eroded dentin in teeth submitted to abrasive wear with desensitizing dentifrices. Material and Methods: Bovine dentin specimens were polished and immersed in 10 mL of citric acid (pH=3.2) for 2 h. The eroded specimens were submitted to mechanic brushing according to the 4 dentifrices adopted: Colgate Total (control); Colgate Sensitive Pro-Relief; Sensodyne Repair & Protect; or Sensodyne Rapid Relief. Afterwards, it was conditioned in 37% aqueous phosphoric acid solution. Wettability of 80 specimens (n=10) brushed for 7 or 21 days was evaluated by measuring the contact angle between the dentin surface and a drop of the adhesive Single Bond Universal® (3M) with a goniometer. Changes in the surface morphology of 12 specimens (n = 3) brushed for 21 days were followed by confocal laser scanning microscopy (CLSM). Data were analyzed by two-way ANOVA and Tukey test (p > 0.05). Results: Groups treated with desensitizing dentifrices did not differ significantly (p ≤ 0.05). Surface treatment and abrasive wear did not interact significantly (p ≤ 0.05). Brushing along 7 days gave the smallest contact angle value (p ≥ 0.05). CLSM images showed morphological changes for all the groups. Conclusion: The desensitizing dentifrices did not interfere in eroded dentin wettability after brushing along 7 or 21 days. Brushing with any of the dentifrices along 21 days promoted open dentinal tubules.(AU)


Objetivo: Analisar a aplicação de um adesivo na superfície de dentina erodida em dentes submetidos ao desgaste abrasivo com agentes dessensibilizantes. Material e Métodos: Espécimes de dentina bovina foram polidos e imersos em 10 mL de ácido cítrico (pH=3,2) por 2 h. Os espécimes erodidos foram submetidos à escovação mecânica de acordo com os 4 dentifrícios adotados: Colgate Total (controle); Colgate Sensitive Pro-Alívio; Sensodyne Repair & Protect; ou Sensodyne Rápido Alívio. Em seguida, foram condicionados em ácido fosfórico a 37%. A molhabilidade de 80 espécimes (n=10) escovados por 7 ou 21 dias foi avaliada medindo-se o ângulo de contato entre a superfície dentinária com uma gota do adesivo Single Bond Universal® (3M) por um goniômetro. Alterações na morfologia da superfície de 12 espécimes (n = 3) escovados por 21 dias foram seguidos por Microscopia Confocal de Varredura a Laser (MCVL). Os dados foram analisados por ANOVA dois fatores e teste de Tukey (p > 0,05). Resultados: Os grupos tratados com dentifrícios dessensibilizantes não diferiram significativamente (p ≤ 0,05). O tratamento de superfície e o desgaste abrasivo não interagiram significativamente (p ≤ 0,05). A escovação ao longo de 7 dias apresentou o menor valor de ângulo de contato (p ≥ 0,05). As imagens do MCVL mostraram alterações morfológicas para todos os grupos. Conclusão: Os dentifrícios dessensibilizantes não interferiram na molhabilidade da dentina erodida após escovação ao longo de 7 ou 21 dias. A escovação com qualquer um dos dentifrícios ao longo de 21 dias promoveu a abertura dos túbulos dentinários (AU)


Subject(s)
Animals , Cattle , Toothbrushing , Wettability , Dentifrices , Dentin , Dentin Desensitizing Agents
2.
Braz. j. oral sci ; 20: e213961, jan.-dez. 2021. tab
Article in English | LILACS, BBO | ID: biblio-1254644

ABSTRACT

Aim: This cross-sectional study aimed to investigate where Brazilian dental students seek information about COVID-19 by a self-administered web-based questionnaire. Methods: A social network campaign on Instagram was raised to approach the target population. The dental students responded to a multiple-response question asking where or with whom they get information about COVID-19. The possible answers were government official websites or health and education institutions websites, TV Programs, professors, social media, scientific articles, health professionals, and family members. The data were analyzed by descriptive statistics, and the frequency distributions of responses were evaluated by gender, age, type of institution, and year of enrollment. Results: A total of 833 valid responses were received. The main source of information used by the dental students were government official websites or health and education institutions websites, which were reported by 739 (88.7%) participants. In the sequence, 477 (57.3%) participants chose health professionals while 468 (56.2%) chose scientific articles as information sources. The use of social media was reported by 451 (54.1%) students, while TV programs were information sources used by 332 (39.9%) students. The least used information sources were professors, reported by 317 (38.1%) students, and family members, chosen only by 65 (7.8%) participants. Conclusion: Brazilian dental students rely on multiple information sources to stay informed about COVID-19, mainly focusing their information-seeking behavior on governmental and health professional's websites


Subject(s)
Schools, Dental , Students, Dental , Surveys and Questionnaires , Information Seeking Behavior , Social Media , COVID-19
3.
Rev. Cient. CRO-RJ (Online) ; 3(3): 56-61, Sept.-Dec. 2018.
Article in English | LILACS, BBO | ID: biblio-1022027

ABSTRACT

Objective: The aim of this study was to evaluate the effect of different concentrations of a natural antioxidant (grape seed extract) on the bond strength of the restorative material to the bleached enamel. Methods: Forty fragments of healthy bovine incisors were randomly divided into four groups (n = 10): Group I: no bleaching; Group II: Bleaching with 35% hydrogen peroxide (HP) and without post-treatment; Group III: Bleaching with 35% HP + 5% grape seed extract; and Group IV: Bleaching with 35% HP + 10% grape seed extract. The bond strength at the adhesive interface was evaluated using the shear test (MPa). The data were analyzed by the analysis of variance (ANOVA) and Tukey test ( =0.05%). The fracture types were also analyzed and classified into: adhesive, cohesive or mixed. Results: Only Group III (bleached + 5% grape seed extract) had a significant increase (p<0.001) in bond strength values when compared to Group II bleached, without post- reatment). All groups showed a predominance of the adhesive type of fracture. Conclusion: It could be concluded that tooth bleaching decreases the bond strength to bleached enamel and 5% grape seed extract applied after dental bleaching improves the bond strength between the restorative material and the bleached enamel.


Objetivo: Este trabalho teve por objetivo avaliar in vitro o efeito de um antioxidante natural (extrato de semente de uva) em diferentes concentrações, na resistência de união do material restaurador ao esmalte clareado. Métodos: Quarenta fragmentos de incisivos bovinos hígidos, foram divididos aleatoriamente em quatro grupos (n=10): Grupo I: sem clareamento; Grupo II: clareado com peróxido de hidrogênio 35% (PH) e sem pós-tratamento; GIII: clareado PH 35% + extrato de semente de uva 5%; e Grupo IV: clareado com PH 35% + extrato de semente de uva 10%. A resistência de união da interface esmalte/material restaurador foi avaliada por meio do teste de cisalhamento (MPa). Os dados foram analisados pela análise de variância (ANOVA) e testes de Tukey ( =0,05%). Os tipos de fratura também foram analisados e classificados em: adesiva, coesiva ou mista. Resultados: Apenas o Grupo III (clareado + extrato de semente de uva 5%) apresentou aumento estatisticamente significante (p<0,001). dos valores de resistência de união comparado ao Grupo II (clareado e sem pós-tratamento). Todos os grupos mostraram um predomínio do tipo de fratura adesiva. Conclusão: O clareamento dental diminui significativamente a força de adesão ao esmalte dental clareado, e o extrato de semente de uva 5% aplicado após o clareamento dental melhora a resistência de união entre o material restaurador e o esmalte clareado.


Subject(s)
Cattle , Tooth Bleaching , In Vitro Techniques , Dental Enamel , Grape Seed Extract , Antioxidants
4.
J. appl. oral sci ; 26: e20170029, 2018. tab, graf
Article in English | LILACS, BBO | ID: biblio-893704

ABSTRACT

Abstract Literature has reported positive results regarding the use of lasers in the control of erosive lesions; however, evaluating whether they are effective in the control of the progression of erosive/abrasive lesions is important. Objectives This study aimed to evaluate the effect of the Er:YAG laser irradiation in controlling the progression of erosion associated with abrasive lesions in enamel. Material and methods Bovine incisors were sectioned, flattened and polished. Forty-eight enamel slabs were subjected to treatment in an intraoral phase. Twelve volunteers used an intraoral appliance containing one slab that was irradiated with an Er:YAG laser (5.2 J/cm2, 85 mJ, 2 Hz) and another non-irradiated slab on each side of the appliance, during one phase of 5 d, under a split-mouth design. Devices were subjected to erosive challenges (1% citric acid, 5 min, 3 times a day) and abrasive challenges one h after (brushing force of 1.5 N for 15 s) randomly and independently on each side of the device. Measurements of enamel loss were performed via 3D optical profilometry (μm). We analyzed data using the Kruskal-Wallis and Mann-Whitney tests and morphological characteristics via scanning electron microscopy. Results Following erosive and abrasive challenges, the group that was irradiated with the Er:YAG laser presented less loss of structure than the non-irradiated group. The group that underwent erosion and irradiation did not exhibit a significant difference from the non-irradiated group. Conclusion Irradiation with the Er:YAG laser did not control the loss of structure of enamel subjected to erosion but did control abrasion after erosion.


Subject(s)
Animals , Cattle , Tooth Abrasion/prevention & control , Tooth Erosion/prevention & control , Dental Enamel/radiation effects , Lasers, Solid-State/therapeutic use , Surface Properties/radiation effects , Materials Testing , Microscopy, Electron, Scanning , Reproducibility of Results , Statistics, Nonparametric , Disease Progression , Citric Acid/chemistry , Imaging, Three-Dimensional , Dental Enamel/drug effects , Hardness Tests
5.
Braz. dent. j ; 28(4): 489-497, July-Aug. 2017. tab, graf
Article in English | LILACS | ID: biblio-888668

ABSTRACT

Abstract This study evaluated the effect of a bioactive glass ceramic for the control of erosion and caries lesions. Fragments (n=10) of bovine enamel and root dentin received daily application of different treatments (Biosilicate; Acidulated Phosphate Fluoride- APF; Untreated - control) during the performance of erosive cycles. Surfaces were analyzed with 3D optical profilometry to quantify the superficial loss in four periods (1, 7, 14 and 21 days), as well as the lesion depth with confocal laser scanning microscopy. For caries progression assessment, initial Knoop microhardness was measured on enamel bovine fragments. Initial carious lesions were developed and specimens were divided into three groups (n=10), according to the daily topical application (Biosilicate; APF; no application - control), during the de-remineralization cycles for 14 days. Final microhardness was obtained to calculate the change of surface microhardness. Subsurface demineralization was analyzed using cross-sectional microhardness (depths 10, 30, 50, 70, 90, 110 and 220 µm). Data were tested using ANOVA and Tukey's test (a=5%). Results of erosive evaluation showed that Biosilicate promoted the lowest (p<0.05) values of surface loss, regardless of time, for both enamel and dentin; APF promoted lower (p<0.05) surface loss than control; analyzing different periods of time, APF did not show difference (p>0.05) between 14 and 21 days of demineralization. Results of enamel caries assessment showed that Biosilicate resulted in higher (p<0.05) surface and subsurface microhardness than both APF and control-applications. It may be concluded that Biosilicate application showed a higher potential to reduce surface loss and development of erosion and caries lesions.


Resumo Este estudo avaliou o efeito de uma vitrocerâmica bioativa para o controle de lesões de erosão e cárie. Fragmentos (n=10) de esmalte bovino e dentina radicular receberam aplicação diária de diferentes tratamentos (Biosilicato; Fluoreto de Fosfato Acidulado - APF; não tratado - controle) durante a realização de ciclos erosivos. As superfícies foram analisadas com profilometria óptica 3D para quantificar a perda superficial em quatro períodos (1, 7, 14 e 21 dias), bem como a profundidade da lesão com microscopia confocal de varredura a laser. Para a avaliação da progressão de cárie, foi obtida a microdureza Knoop inicial de fragmentos de esmalte bovino. As lesões cariosas iniciais foram desenvolvidas e os espécimes foram divididos em três grupos (n =10), de acordo com a aplicação tópica diária (Biosilicato; APF; sem aplicação - controle) durante os ciclos de desmineralização por 14 dias. A microdureza final foi obtida para calcular a perda da microdureza superficial. A desmineralização sub-superficial foi analisada utilizando microdureza transversal (profundidades 10, 30, 50, 70, 90, 110 e 220 μm). Os dados foram testados utilizando ANOVA e teste de Tukey (α=5%). Os resultados da avaliação erosiva mostraram que o Biosilicato promoveu os menores valores (p <0,05) de perda superficial, independente do tempo, tanto para o esmalte como para a dentina; APF promoveu menor (p <0,05) perda de superfície do que controle; analisando os períodos de tempo, APF não mostrou diferença (p>0,05) entre 14 e 21 dias de desmineralização. Os resultados da avaliação da cárie no esmalte mostraram que o Biosilicato resultou em maiores (p<0,05) valores de microdureza superficial e subsuperficial do que as aplicações APF e controle. Pode-se concluir que a aplicação de Biosilicato apresentou maior potencial de redução da perda superficial e desenvolvimento de lesões de erosão e cárie.


Subject(s)
Animals , Cattle , Acidulated Phosphate Fluoride , Ceramics , Dentin/pathology , Glass , Tooth Erosion/prevention & control , Dental Caries/prevention & control , Hardness Tests , Microscopy, Confocal , Microscopy, Electron, Scanning , X-Ray Diffraction
6.
Braz. dent. j ; 27(4): 442-445, July-Aug. 2016. tab, graf
Article in English | LILACS | ID: lil-794610

ABSTRACT

Abstract This study evaluated the effect of matrix metalloproteinase (MMP) inhibitors - 2% (CHX) and sodium fluoride (NaF) (5000 ppm) - on microtensile bond strength (μTBS) of composite resin to Er:YAG laser-irradiated dentin after chemical degradation of the bond interface. The occlusal surface of forty sound human molars was removed exposing the dentin surface (n=10), which was polished, irradiated with Er:YAG laser, acid etched and dried. Twenty specimens were rewetted with 2% CHX (control group) and 20 were rewetted with NaF (5000 ppm). The adhesive system was applied and a 4-mm-high plateau of light-cured composite resin was built up. Resin-dentin sticks were obtained with a rectangular cross-sectional area (0.8-1 mm2) and were either stored in water at 37 ?#61616;C for 24 h or submitted to chemical degradation. For chemical degradation, they were immersed in 10% NaOCl aqueous solution for 5 h and rinsed in water for 1 h. The sticks were submitted to microtensile test in a mechanical testing machine at 0.5 mm/min until failure. Fracture pattern was analyzed using SEM. μTBS values were calculated in MPa and submitted to analysis of variance ANOVA (α=0.05). The variance analysis showed that the 'MMP inhibitor' and 'degradation' factors (p=0.214 and p=0.093, respectively) and interaction between the factors were not statistically significant (p=0.143). Mixed failure predominated in all groups. In conclusion, the 2% CHX and NaF 5000 ppm presented similar μTBS of composite resin to laser-irradiated dentin before and after chemical degradation.


Resumo Este estudo avaliou o efeito dos inibidores de metaloproteinase, clorexidina 2% e fluoreto de sódio (5000 ppm), na resistência de união entre a dentina irradiada por laser Er:YAG e a resina composta após a degradação química da interface de união. A superfície oclusal de quarenta molares humanos hígidos (n=10) foi removida expondo uma superfície de dentina, que foi polida, irradiada com laser Er:YAG, condicionada com ácido e seca. Vinte espécimes foram re-umedecidos com clorexidina 2% (Grupo controle) e 20 com fluoreto de sódio (5000 ppm). O sistema adesivo foi aplicado e um platô de resina composta fotopolimerizável de 4 mm de altura foi construído. Palitos de resina-dentina foram obtidos com secção transversal retangular (0,8-1 mm2). Eles foram armazenados em água (24 h a 37 ?#61616;C) ou submetidos a degradação química. Para a degradação química, foram imersos em solução aquosa de hipoclorito de sódio a 10% durante 5 horas e lavados em água durante 1 h. Os palitos foram submetidos ao teste de microtração em uma máquina de ensaios mecânicos a 0,5 mm/min até a fratura. O padrão de fratura foi analisado em MEV. Os valores de resistência de união foram calculados em MPa e submetidos à análise de variância ANOVA (α=0,05). A análise de variância mostrou que os fatores inibidor de metaloproteinases e degradação (p=0,214 e p=0,093, respectivamente), e a interação entre os fatores não foram estatisticamente significantes (p=0,143). A predominância de falha mista foi detectada para todos os grupos. Em conclusão, a clorexidina a 2% e fluoreto de sódio (ppm 5000) apresentaram resistência de união entre dentina irradiada e resina composta semelhante antes e após a degradação química.


Subject(s)
Composite Resins , Lasers, Solid-State , Metalloproteases/drug effects , Protease Inhibitors/pharmacology , Tensile Strength , Metalloproteases/metabolism
7.
Braz. dent. j ; 26(6): 671-677, Nov.-Dec. 2015. tab, graf
Article in English | LILACS | ID: lil-769562

ABSTRACT

This study evaluated the combined effect of fluoride varnish and Er:YAG laser on the permeability of eroded bovine root dentin. After initial erosive challenge followed by a remineralization period, the specimens were divided in two groups according to the treatment - fluoride varnish and non-fluoride varnish - and were subdivided according to the irradiation protocol: Er:YAG laser (100 mJ, 3 Hz, 12.8 J/cm2per pulse, non-contact and defocus mode) and non-irradiated. After a lead-in period, 7 volunteers wore a palatal device containing 4 specimens that were subjected to erosive challenges. At the first experimental phase, 4 volunteers used specimens treated with fluoride varnish and fluoride varnish+Er:YAG laser and 3 volunteers used specimens treated with non-fluoride varnish and non-fluoride varnish+Er:YAG laser. After a washout period, volunteers were crossed to treatments, characterizing a 2x2 crossover experiment. At the end of the experimental phase, the quantitative response variable was obtained by permeability analysis and the qualitative response by scanning electron microscopy (SEM). Two-way ANOVA and Tukey-Kramer's test revealed that specimens treated with fluoride varnish+Er:YAG laser showed the lowest permeability and a significant difference was found between this group and the others. When varnish (fluoride/non-fluoride) was applied in the absence of Er:YAG laser, higher permeability was found when compared to the laser-treated groups. SEM evaluations showed partially or completely obliterated dentinal tubules when specimens were treated with fluoride varnish+Er:YAG laser. It may be concluded that Er:YAG laser was able to control the permeability of eroded root dentin and the combination with fluoride varnish increased laser action.


Resumo Esse estudo avaliou o feito combinado do verniz fluoretado ao laser de Er:YAG na permeabilidade da dentina radicular erodida. Fragmentos de dentina radicular bovina, foram submetidos a um desafio erosivo inicial com ácido cítrico, que foi seguido por um período de remineralização. Posteriormente, os espécimes foram divididos em relação aos tratamentos: verniz (fluoretado e não fluoretado) e subdivididos de acordo com a irradiação: laser de Er:YAG (100 mJ, 3 Hz, 12.8 J/cm2 por pulso, sem contato e modo não focado) e não irradiado. Após um período de lead in, 7 voluntários utilizaram um dispositivo palatino contendo 4 espécimes que foram submetidos a desafios erosivos. Na primeira fase do experimento, 4 voluntários utilizaram dispositivos com fragmentos tratados com verniz fluoretado e verniz fluoretado+laser de Er:YAG e 3 voluntários utilizaram espécimes tratados com verniz não fluoretado e verniz não fluoretado+laser de Er:YAG. Depois de um período de wash-out, os voluntários foram cruzados em relação aos tratamentos, caracterizando um experimento cross-over 2x2. Ao final de cada fase experimental, a variável resposta quantitativa foi obtida através da análise de permeabilidade e a qualitativa por microscopia eletrônica de varredura (MEV). A ANOVA dois critérios e teste de Tukey-Kramer revelou que as amostras tratadas com verniz fluoretado+laser de Er:YAG mostraram menor permeabilidade e uma diferença significativa foi encontrada entre este grupo, quando comparado aos demais grupos. Quando o verniz (fluoretado/não fluoretado) foram aplicados na ausência do laser de Er:YAG maiores valores de permeabilidade foram encontrados quando comparados com os grupos irradiados com o laser. A MEV demostrou túbulos dentinários parcialmente ou completamente ocluídos quando as amostras foram tratadas com verniz fluoretado+laser de Er: YAG. Pode-se concluir que o laser de Er:YAG foi capaz de controlar a permeabilidade da dentina radicular erodida e essa ação é aumentada quando o laser está associado ao verniz fluoretado.


Subject(s)
Humans , Male , Female , Adolescent , Adult , Young Adult , Dentin , Fluorides/chemistry , Lasers, Solid-State , Paint , Tooth Erosion , Cross-Over Studies , Double-Blind Method , Microscopy, Electron, Scanning , Permeability
8.
Braz. dent. j ; 26(3): 268-271, May-Jun/2015. tab
Article in English | LILACS | ID: lil-751860

ABSTRACT

The purpose of this study was to determine the influence of hydrochloric acid on surface roughness of composite resins subjected to brushing. Sixty samples measuring 2 mm thick x 6 mm diameter were prepared and used as experimental units. The study presented a 3x2 factorial design, in which the factors were composite resin (n=20), at 3 levels: microhybrid composite (Z100), nanofilled composite (FiltekTM Supreme), nanohybrid composite (Ice), and acid challenge (n=10) at 2 levels: absence and presence. Acid challenge was performed by immersion of specimens in hydrochloric acid (pH 1.2) for 1 min, 4 times per day for 7 days. The specimens not subjected to acid challenge were stored in 15 mL of artificial saliva at 37 oC. Afterwards, all specimens were submitted to abrasive challenge by a brushing cycle performed with a 200 g weight at a speed of 356 rpm, totaling 17.8 cycles. Surface roughness measurements (Ra) were performed and analyzed by ANOVA and Tukey test (p≤0.05). Surface roughness values were higher in the presence (1.07±0.24) as compared with the absence of hydrochloric acid (0.72±0.04). Surface roughness values were higher for microhybrid (1.01±0.27) compared with nanofilled (0.68 ±0.09) and nanohybrid (0.48±0.15) composites when the specimens were not subjects to acid challenge. In the presence of hydrochloric acid, microhybrid (1.26±0.28) and nanofilled (1.18±0,30) composites presents higher surface roughness values compared with nanohybrid (0.77±0.15). The hydrochloric acid affected the surface roughness of composite resin subjected to brushing.


Este estudo avaliou a influencia do ácido clorídrico na rugosidade superficial de resinas compostas submetidas a escovação. Sessenta corpos de prova medindo 2 mm de espessura x 6 mm de diâmetro foram confeccionados e utilizados como unidades experimentais. O presente estudo envolve uma análise fatorial 3x2, onde os fatores foram resina composta (n=20), com 3 níveis: resina composta microhíbrida (Z100), nanoparticulada (Filtek TM Supreme) e nanohíbrida (Ice); e desafio ácido (n=10), com 2 níveis: ausência e presença. O desafio ácido foi realizado por meio da imersão em ácido clorídrico (pH 1,2) por 4 h diárias, 1 min cada imersão, durante 7 dias. Os espécimes que não foram submetidos ao desafio ácido foram armazenados em 15 mL de saliva artificial a 37 °C. Todos os espécimes foram submetidos ao desafio abrasivo. O processo de escovação foi realizado com 200 g de peso, com velocidade de 356 rpm, totalizando 17,8 ciclos. As medidas de rugosidade superficial (Ra) foram realizadas e analisadas por meio da ANOVA e teste de Tukey (p<0,05). Os valores de rugosidade superficial foram maiores na presença (1,07±0,24)quando comparado com a ausencia do ácido hidroclorídrico (0,72±0,04). A resina microhíbrida (1,01±0,27) apresentou maior rugosidade superficial que as resinas nanoparticulada (0,68±0,09) e nanohíbrida (0,48±0,15) quando os espécimes não foram submetidos ao desafio ácido. Na presença do ácido hidroclorídrico, a resina microhíbrida (1,26±0,28) e a resina nanoparticulada (1,18±0,30) apresentou maior valor de rugosidade superficia comparado com a resina nanohíbrida (0.77±0.15). O ácido hidroclorídrico influenciou a rugosidade superficial da resina composta submetida a escovação.


Subject(s)
Composite Resins , Hydrochloric Acid/chemistry , Hydrogen-Ion Concentration , Saliva , Surface Properties
9.
RSBO (Impr.) ; 9(4): 282-287, Oct.-Dec. 2012. ilus, tab
Article in English | LILACS-Express | LILACS | ID: lil-755714

ABSTRACT

Introduction and objective: The aim of this study was to assess the surface and the substrate/glass ionomer cement (GIC) interface after Er:YAG laser irradiation by means of scanning electron microcopy. Material and methods: Thirty human third molars were selected and had their roots removed. Crowns were sectioned to obtain discs that were randomly assigned to three groups according to the surface pretreatment: 40% polyacrylic acid (control); Er:YAG laser irradiation (80mJ/2Hz) or Er:YAG laser followed by 40% polyacrylic acid. Two discs of each group were put aside to the surface analysis and the others were bisected. One half received Ketac-Fil and the other received Fuji II LC. Specimens were prepared for SEM and were analyzed under different magnifications. Results: Er:YAG laser group showed no adhesive interface for both enamel and dentin, but strongly damaged the interface build-up for dentin/Fuji II LC. The application of laser irradiation followed by the polyacrylic acid exhibited gaps and irregularities for both substrates. Conclusion: Er:YAG laser irradiation combined or not with 40% polyacrylic acid produced a surface unfavorable for GIC interaction, especially for the resin-modified ones.

10.
Braz. oral res ; 26(3): 209-214, May-June 2012. tab
Article in English | LILACS | ID: lil-622935

ABSTRACT

The aim of this study was to determine the influence of mouthrinses on the surface roughness of a nanofilled composite resin after toothbrushing. One hundred nanofilled composite resin specimens were prepared and randomly distributed into two groups-brushed and non-brushed-and then assigned to five subgroups, according to the mouthrinse solutions (n = 10): Colgate Plax Fresh Mint, Oral B, Cepacol, Colgate Plax, and artificial saliva. Each sample was immersed in 20 mL of the mouthrinses for 1 minute, 5 days per week, twice a day, for a 3-week period. The control group used in the study was one in which the specimens were not subjected to brushing and remained only in artificial saliva. Toothbrushing was performed once a week for 1 minute, for 3 weeks. Surface roughness measurements (Ra) were performed after the immersion period and toothbrushing, by means of a profilometer. Data were analyzed by two-way ANOVA and Tukey's test. Analysis revealed that the association between toothbrushing and Colgate Plax Fresh Mint produced the lowest surface roughness (p < 0.05). All other groups tested (Oral B, Cepacol, Colgate Plax, artificial saliva) exhibited no statistically significant differences between surfaces, whether subjected to toothbrushing or not (p < 0.05). It was concluded that the surface roughness of the nanofilled composite resin tested can be influenced by the mouthrinse associated with toothbrushing.


Subject(s)
Humans , Composite Resins/chemistry , Mouthwashes/chemistry , Nanocomposites/chemistry , Toothbrushing , Analysis of Variance , Immersion , Materials Testing , Random Allocation , Surface Properties , Saliva, Artificial/chemistry , Time Factors , Tooth Abrasion
11.
Braz. dent. j ; 23(4): 367-372, 2012. tab
Article in English | LILACS | ID: lil-658012

ABSTRACT

This study evaluated by an in vitro model the effect of beverages on dental enamel previously subjected to erosive challenge with hydrochloric acid. The factor under study was the type of beverage, in five levels: Sprite® Zero Low-calorie Soda Lime (positive control), Parmalat® ultra high temperature (UHT) milk, Ades® Original soymilk, Leão® Ice Tea Zero ready-to-drink low-calorie peach-flavored black teaand Prata® natural mineral water (negative control). Seventy-five bovine enamel specimens were distributed among the five types of beverages (n=15), according to a randomized complete block design. For the formation of erosive wear lesions, the specimens were immersed in 10 mL aqueous solution of hydrochloric acid 0.01 M for 2 min. Subsequently, the specimens were immersed in 20 mL of the beverages for 1 min, twice daily for 2 days at room temperature. In between, the specimens were kept in 20 mL of artificial saliva at 37ºC. The response variable was the quantitative enamel microhardness. ANOVA and Tukey's test showed highly significant differences (p<0.00001) in the enamel exposed to hydrochloric acid and beverages. The soft drink caused a significantly higher decrease in microhardness compared with the other beverages. The black tea caused a significantly higher reduction in microhardness than the mineral water, UHT milk and soymilk, but lower than the soft drink. Among the analyzed beverages, the soft drink and the black tea caused the most deleterious effects on dental enamel microhardness.


Este estudo avaliou através de um modelo in vitro o efeito de bebidas no esmalte dental previamente submetido a desafio erosivo com ácido clorídrico. O fator em estudo foi o tipo de bebida, em cinco níveis: Sprite Zero (Coca-Cola® Brasil) controle positivo, leite integral Ultra High Temperature (Parmalat®), extrato de soja integral (Ades® Original), chá preto com baixo teor calórico sabor pêssego (Leão Ice Tea Zero Coca-Cola® Brasil) e água mineral Prata® (controle negativo). Setenta e cinco espécimes de esmalte bovino foram distribuídos entre os cinco tipos de bebidas (n = 15), de acordo com delineamento em blocos completos e casualizados. Para a formação das lesões de desgaste erosivo, os espécimes foram imersos durante 2 min em 10 mL de solução aquosa de ácido clorídrico 0,01 M. Subsequentemente foram imersos em 20 mL das bebidas por 1 min, duas vezes ao dia durante 2 dias, em temperatura ambiente. Nos intervalos entre as imersões os espécimes permaneceram em saliva artificial a 37ºC. A variável de resposta quantitativa foi microdureza superficial do esmalte. ANOVA e teste de Tukey demonstraram diferenças altamente significativas (p <0,00001) no esmalte exposto ao ácido clorídrico e às bebidas. O refrigerante provocou diminuição da microdureza superficial significativamente maior do que as demais bebidas. O chá preto provocou diminuição da microdureza significativamente maior que a água mineral, o leite UHT e o extrato de soja, porém menor que o refrigerante.Entre as bebidas analisadas, refrigerante e chá preto demonstraram efeitos mais deletérios sobre a microdureza do esmalte dental.


Subject(s)
Animals , Cattle , Beverages/classification , Dental Enamel/pathology , Hydrochloric Acid/adverse effects , Tooth Erosion/chemically induced , Beverages/adverse effects , Carbonated Beverages/adverse effects , Dental Enamel/drug effects , Fluorides/analysis , Hardness , Humidity , Hydrogen-Ion Concentration , Ion-Selective Electrodes , Milk , Mineral Waters/adverse effects , Random Allocation , Soy Milk , Saliva, Artificial/chemistry , Temperature , Time Factors , Tea/adverse effects
12.
Rev. bras. odontol ; 68(2): 191-194, jul.-dez. 2011. ilus
Article in Portuguese | LILACS, BBO | ID: biblio-857505

ABSTRACT

Frente à dificuldade de controlar processos de desmineralização do esmalte, novas tecnologias vêm sendo estudadas como o emprego da irradiação com laser de CO2. Assim, o objetivo deste trabalho foi apresentar uma revisão de literatura crítica do laser de CO2 no controle da desmineralização do esmalte, abordando seu mecanismo de ação em esmalte, parâmetros de utilização para a estrutura dental e sua associação a agentes fluoretados. O laser de CO2 parece ser um método promissor no controle da desmineralização do esmalte, porém, mais estudos são necessários para empregabilidade clínica. O efeito sinérgico com flúor, mesmo com diferentes agentes fluoretados, revelou resultados positivos no controle da desmineralização do esmalte.


Subject(s)
Tooth Demineralization/prevention & control , Fluorine , Lasers, Gas/therapeutic use
13.
Rev. paul. odontol ; 33(2): 8-11, abr.-jun. 2011.
Article in Portuguese | LILACS | ID: lil-605236

ABSTRACT

Nas últimas décadas, um declínio na prevalência da doença cárie tem sido constatado nos países industrailizados, no entanto, ainda representa umas das doenças que mais acomete os seres humanos, sendo considerada um problema de saúde pública. Uma nova visão da Odontologia, denominada Intervenção Mínima, tem determinado novas tendências no sentido de abranger procedimetos mais biológicos, preventivos e menos invasivos, visando a preservação de tecidos dentais. Essa filosofia é dependente de um diagnóstico precoce. Assim, como o diagnóstico difedigno do processo de cárie por inspeção visual é limitado, existe a necessidade de detectar a doença no seu estágio mais inicial, a fim de apoiar as decisões de tratamento. Dessa forma, nos últimos anos têm surgido métodos auxiliares de diagnóstico da doença e consequente aumento do interesse por analisar a eficácia desses métodos, uma vez técnicas baseadas apenas no exame visual e radiográfico não são tão eficazes em detectar níveis iniciais de perdas minerais do esmalte dental. O laser diodo para diagnóstico de cárie foi introduzido há alguns anos. Esses sistemas baseados na autofluorescência dos tecidos dentais parecem oferecer maior eficácia na realização de diagnóstico confiável e preciso das primeiras fases da desmineralização do esmalte dental. Para tanto, esta revisão avalia criticamente o diagnóstico de cárie por fluorescência a laser.


In recent decades, a decline in the prevalence of caries has been observed in industrialized countries, yet it represents one of the most common diseases in man and is considered a public health problem. A new approach or the treatment of dental caries is advocated by Mininmal Intervention Dentistry. It emphasizes a more biological preventive and less invasive procedures, in order to preserve more dental tissue. This philosophy dependents on early diagnosis. Since a reliable diagnosis of dental caries by visual inspection and radiographic examination is limited there is a need to detect the disease in its earlist stage, to suport treatment decisions. The diode laser for caries diagnosis was introduced some years ago. These systems are based on self-fluorescence of the tissues and appear to offer greater efficacy in achieving a reliable and occurate diagnosis of earlu stages of enamel demineralization. Thus, this rewiew critically evaluares caries diagnosis using laser flueorescence.


Subject(s)
Dental Caries , Diagnosis , Lasers, Semiconductor
14.
Article in Portuguese | LILACS, BBO | ID: lil-655326

ABSTRACT

Introdução: A erosão dental é definida como a perda progressiva e irreversível de tecido dental duro por um processo químico que não envolve a ação bacteriana. A sua etiologia apresenta caráter multifatorial e está relacionada à fonte de ácidos de origem extrínseca ou intrínseca. Dentre os fatores de origem intrínseca, esta condição tem sido relacionada à presença de refluxo gastroesofágico, principalmente em crianças. O refluxo gastroesofágico refere-se ao fluxo retrógrado, repetido e involuntário do conteúdo gástrico para o esôfago, que pode consistir de gás (eructação) ou fluido (regurgitação).Objetivo: Este trabalho discutiu, por meio de uma revisão de literatura, conhecimentos sobre a etiopatogenia e o diagnóstico do refluxo gastroesofágico e as evidências científicas acerca de sua associação com a erosão dental na infância. Foram apresentadas também algumas estratégias para a prevenção e o controle dessas lesões. Conclusão: O controle da erosão pela doença do refluxo gastroesofágico deve priorizar a eliminação ou a redução do contato do suco gástrico com a estrutura dental, por meio do tratamento da patologia de base; porém, durante o manejo do refluxo, o profissional deve estar atento à necessidade de prescrever ou adotar estratégias que minimizem o desgaste dental, como bochechar com solução aquosa de bicarbonato e adiar a escovação imediatamente após os episódios de regurgitação ou de êmese, evitar o consumo frequente de bebidas e de alimentos ácidos e otimizar a remineralização do esmalte ou da dentina por meio da aplicação de produtos fluoretados


Introduction: Dental erosion is defined as the progressive and irreversible loss of hard dental tissue by a chemical process that does not involves bacteria. Its etiology has a multifatorial nature and is related to acids of extrinsic or intrinsic origin. Among the intrinsic factors, this condition has been associated with the presence of gastroesophageal reflux, especially in children. Gastroesophageal reflux refers to the repeated and involuntary retrograde flow of the gastric content to esophagus in the form of gas (eructation) or fluid (regurgitation).Objective: This literature review addressed the knowledge of the etiopathogenesis and diagnosis of gastroesophageal reflux and the scientific evidence about its association with dental erosion during childhood. Some strategies for the prevention and control of these lesions were also presented. Conclusion: The control of dental erosion caused by gastroesophageal reflux disease should focus on eliminating or reducing the contact of gastric juice with the dental structures by treating the causative pathology. However, while dealing with the gastroesophageal reflux, the dentist should identify the need of prescribing and adopting strategies that minimize dental wear, such as, using oral rinses with a bicarbonate aqueous solution; delaying toothbrushing immediately after regurgitation or emesis episodes; avoiding frequent consumption of beverages and acid foods; and optimizing enamel/dentin remineralization by the application of fluoridated products


Subject(s)
Child , Tooth Wear/diagnosis , Diagnosis, Oral , Tooth Erosion/pathology , Tooth Erosion/prevention & control , Esophagitis/prevention & control , Gastroesophageal Reflux/complications , Gastroesophageal Reflux/diagnosis
15.
J. appl. oral sci ; 18(4): 385-389, July-Aug. 2010. ilus, tab
Article in English | LILACS | ID: lil-557109

ABSTRACT

Chemical substances used during biomechanical preparation of root canals can alter the composition of dentin surface and affect the interaction with restorative materials. OBJECTIVE: The purpose of this study was to evaluate the microtensile bond strength (µTBS) of a self-etching adhesive system to dentin irrigated with sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA). MATERIAL AND METHODS: Thirty human third molars were sectioned 3 mm below the occlusal surface, polished with 600- to 1200-grit silicon carbide papers, and randomly divided into 3 groups: G1 (control): no irrigating solution; G2: 1 percent NaOCl; and G3: 1 percent NaOCl followed by the application of 17 percent EDTA. The specimens received the self-etching adhesive system (XENO III - Dentsply), restored with microhybrid composite resin (Z250 - 3M ESPE), sectioned and trimmed to create 4 hourglass-shaped slabs of each tooth. The slabs were tested in microtensile strength in a universal testing machine (Emic DL 2000) at a crosshead speed of 0.5 mm/min until fracture. The results were analyzed statistically by ANOVA and Newman-Keuls test. RESULTS: Mean µTBS values and standard deviations in MPa were: G1 = 11.89 ± 4.22; G2 = 19.41 ± 5.32; G3 = 11.34 ± 4.73. 1 percent NaOCl increased the adhesive resistance significantly (p<0.001/F=22.5763). The application of 1 percent NaOCl/17 percent EDTA resulted in statistically similar µTBS to the control group. CONCLUSIONS: None of the irrigants affected negatively the µTBS of XENO III to dentin. The use of 1 percent NaOCl alone resulted in higher bond strength than the other treatments. The combination of 1 percent NaOCl and 17 percent EDTA produced similar bond strength to that of untreated dentin.


Subject(s)
Humans , Chelating Agents/chemistry , Dental Bonding , Dentin-Bonding Agents/chemistry , Edetic Acid/chemistry , Root Canal Irrigants/chemistry , Sodium Hypochlorite/chemistry , Adhesiveness , Composite Resins/chemistry , Dental Stress Analysis/instrumentation , Dentin/ultrastructure , Materials Testing , Stress, Mechanical , Tensile Strength
16.
J. appl. oral sci ; 18(4): 421-425, July-Aug. 2010. tab
Article in English | LILACS | ID: lil-557115

ABSTRACT

OBJECTIVE: To assess microleakage in conservative class V cavities prepared with aluminum-oxide air abrasion or turbine and restored with self-etching or etch-and-rinse adhesive systems. Materials and Methods: Forty premolars were randomly assigned to 4 groups (I and II: air abrasion; III and IV: turbine) and class V cavities were prepared on the buccal surfaces. Conditioning approaches were: groups I/III - 37 percent phosphoric acid; groups II/IV - self-priming etchant (Tyrian-SPE). Cavities were restored with One Step Plus/Filtek Z250. After finishing, specimens were thermocycled, immersed in 50 percent silver nitrate, and serially sectioned. Microleakage at the occlusal and cervical interfaces was measured in mm and calculated by a software. Data were subjected to ANOVA and Tukey's test (α=0.05). RESULTS: Marginal seal provided by air abrasion was similar to high-speed handpiece, except for group I. There was SIGNIFICANT difference between enamel and dentin/cementum margins for to group I and II: air abrasion. The etch-and-rinse adhesive system promoted a better marginal seal. At enamel and dentin/cementum margins, the highest microleakage values were found in cavities treated with the self-etching adhesive system. At dentin/cementum margins, high-speed handpiece preparations associated with etch-and-rinse system provided the least dye penetration. CONCLUSION: Marginal seal of cavities prepared with aluminum-oxide air abrasion was different from that of conventionally prepared cavities, and the etch-and-rinse system promoted higher marginal seal at both enamel and dentin margins.


Subject(s)
Humans , Air Abrasion, Dental/methods , Dental Cavity Preparation/methods , Dental Leakage/classification , Acid Etching, Dental/methods , Aluminum Oxide/chemistry , Composite Resins/chemistry , Dental Bonding , Dental High-Speed Equipment , Dental Marginal Adaptation , Dental Polishing , Dental Cavity Preparation/instrumentation , Dental Cementum/ultrastructure , Dental Enamel/ultrastructure , Dental Restoration, Permanent/methods , Dentin-Bonding Agents/chemistry , Dentin/ultrastructure , Materials Testing , Methacrylates/chemistry , Phosphoric Acids/chemistry , Silver Staining , Surface Properties , Temperature
18.
RGO (Porto Alegre) ; 54(4): 351-355, out.-dez. 2006.
Article in Portuguese | LILACS, BBO | ID: lil-461706

ABSTRACT

Novas tecnologias vêm sendo testadas com o intuito de remover cárie e realizar o preparo cavitário, sem causar dor ou desconforto aos pacientes. Entre elas, o laser Er:YAG, alcançou importância clínica por mostrar-se capaz de remover o tecido dental de maneira efetiva, sem causar injúrias térmicas à polpa. Além disso, este sistema vem sendo estudado para o pré-tratamento da superfície dental, como meio de remoção de materiais restauradores estéticos e, mais recentemente, usado na prevenção de cáries secundárias e desinfecção de cavidades, visando auxiliar o cotidiano do profissional e proporcionar mais conforto ao paciente. Esta revisão de literatura esclarece de maneira crítica e objetiva os aspectos importantes da utilização do laser Er:YAG na Odontologia Restauradora.


Subject(s)
Dental Caries/therapy , Lasers/therapeutic use , Preventive Dentistry
19.
Braz. dent. j ; 16(1): 35-38, Jan.-Apr. 2005. tab
Article in English | LILACS | ID: lil-415741

ABSTRACT

Este estudo in vitro avaliou a microinfiltração marginal em cavidades classe V preparadas com jato de óxido de alumínio e restauradas com diferentes sistemas ionôméricos. As cavidades foram preparadas nas superfícies vestibular e lingual de 15 terceiros molares hígidos e foram divididas em três grupos com 10 cavidades cada um. Os seguintes materiais foram utilizados: no grupo I, cimento de ionômero de vidro convencional (Ketac Fil) e nos grupo II e III, cimentos de ionômero de vidro modificado por monômeros resinosos (Vitremer e Fuji II LC, respectivamente). O preparo cavitário foi realizado por meio da aplicação do jato de óxido de alumínio (Kreativ Mach 4.1; New Image), com partículas de 27,5 µm. Após a restauração das cavidades, os dentes foram armazenados durante 24 h em água destilada a 37ºC, polidos e então submetido a termociclagem (500 ciclos), imersos em Rodamina B a 0,2% por 24 h, incluídos e seccionados. A análise da microinfiltração marginal foi realizada por meio de um microscópio óptico acoplado a uma câmera e a um computador. As imagens obtidas foram digitalizadas e analisadas utilizando um software que permite uma análise quantitativa padronizada da microinfiltração, em milímetros. As médias (%) obtidas foram: oclusal - I: 25,76 mais ou menos 34,35; II: 20,00 mais ou menos 42,16; III: 28,25 mais ou menos 41,67; cervical I: 23,72 mais ou menos 41,84; II: 44,22 mais ou menos 49,69; III: 39,27 mais ou menos 50,74. Os dados foram submetidos à análise estatística, utilizando os testes de Kruskall-Wallis e Wilcoxon. Não houve diferença estatisticamente significante (p>0.05) entre os materiais testados nem entre as margens oclusal e cervical. Conclui-se que em cavidades classe V preparadas com ar abrasão e restauradas com cimentos de ionômero de vidro convencional e modificados por monômeros resinosos não houve completo vedamento marginal.


Subject(s)
Humans , Air Abrasion, Dental , Dental Cavity Preparation/methods , Dental Leakage/etiology , Dental Restoration, Permanent/adverse effects , Glass Ionomer Cements , Aluminum Oxide , Air Abrasion, Dental/methods , Composite Resins/chemistry , Dental Marginal Adaptation , Glass Ionomer Cements/chemistry , Image Processing, Computer-Assisted , Maleates , Molar , Resins, Synthetic/chemistry , Statistics, Nonparametric , Video Recording
20.
Rev. bras. odontol ; 62(1/2): 100-103, 2005.
Article in Portuguese | LILACS, BBO | ID: lil-427975

ABSTRACT

Atualmente, a substituição de restaurações com falhas constitui a maior parte de todos os tratamentos dentários. Dessa forma, o objetivo desse estudo foi discutir as razões para substituição de restaurações de amálgama, resina composta e cimento de ionômero de vidro, além de opções de tratamento, com o intuito de evitar a substituição desnecessária das restaurações


Subject(s)
Composite Resins , Dental Amalgam , Dental Restoration Wear , Dental Restoration, Permanent , Glass Ionomer Cements
SELECTION OF CITATIONS
SEARCH DETAIL