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Braz. j. oral sci ; 20: e210445, jan.-dez. 2021. ilus
Article in English | LILACS, BBO | ID: biblio-1253016


Aim. To evaluate the bond durability of two universal adhesives; mild and ultra-mild in both etch-and-rinse and self-etch modes after simulated in-vitro degradation by long-term water storage or thermocycling. Methods. A total of 144 specimens were used in this study; 120 specimens (prepared from 30 teeth) for microshear bond strength testing and fracture mode assessment, and 24 specimens for scanning electron microscopic evaluation (prepared from 24 teeth). Specimens were prepared from 54 recently extracted caries free third molars and randomly divided into 12 groups, according to the adhesive treatment (All Bond or Scotchbond Universal), etching mode (etch-andrinse or self-etch) and aging method (thermocycling or water storage). Each tooth was sectioned mesio-distally into two halves exposing free dentin surface for bonding where dentin substrate 1 mm below the dentino-enamel junction was used. After adhesive application and composite build up, specimens were tested in shear mode after storing in distilled water at 37˚C for 24 hours or 1 year, or after being thermocycled between 5 and 55 °C for 10,000 cycles (n=10). Microshear bond strength (µSBS) was tested using a universal testing machine. Adhesive-dentin interface was examined using scanning electron microscope (SEM) (n=2). Data were analyzed using 3 way AN0VA and pairwise comparisons was performed using Bonferroni correction at significance level of α ≤0.05. Results. Statistical analysis revealed non-significant difference for etching mode in both adhesives (p=0.596). After aging, the bond strength was only reduced in Scotchbond Universal after one year of water storage in both modes (p<0.001). SEM evaluation revealed intact hybrid layer and longer resin tags for etch-and-rinse mode than selfetch mode of both adhesives. Conclusion. The bond strength of universal adhesives is not affected by the etching mode, however its durability was shown to be material dependent

Dental Bonding , Dental Cements , Dentin
Braz. j. oral sci ; 20: e210328, jan.-dez. 2021. ilus
Article in English | LILACS, BBO | ID: biblio-1253738


Aim: The in vitro study evaluated the effect of different concentrations of green tea extract solution (GT) on the bonding durability of etch-and-rinse adhesive system to caries dentin affected (CAD). Methods: Dentinal surfaces of human third molars were polished and submitted to a microbiological caries induction protocol for 14 days. After removal of the infected dentin layer, the samples were randomly divided into 4 groups (n= 10), according to the concentration of GT solution applied in CAD, after acid etching: 0.05%; 0.2%; 2% and NT (no treatment ­ control). After application of a etch-and-rinse adhesive system (Adper Single Bond 2, 3M ESPE), composite resin restorations were performed on the dentin. After 24 hours, the resin-dentin blocks were sectioned 1mm2 specimens, which were subjected to the microtensile test immediately or after 6 months of storage in water. Data were submitted to two-way ANOVA for randomized blocks and Tukey test (α= 5%). Results: There was no effect of double interaction (p= 0.934). The application of 0.2% GT promoted a statistically significant increase in dentin bond strength values in comparison to the condition where GT was not used (p=0.012). There was a significant decrease of bond strength after 6 months of storage, regardless of dentin pretreatment (p = 0.007). The G test identified that there was no statistical difference regarding failure mode (p= 0.326). Conclusion: The concentration of 0.2% improved the bond strength of an etch-and-rinse adhesive system to caries affected dentin, however, none of dentin pretreatments could prevent the decrease in bond strength over time

Tensile Strength , Camellia sinensis , Dental Caries , Dentin
Braz. j. oral sci ; 20: e219342, jan.-dez. 2021. ilus
Article in English | LILACS, BBO | ID: biblio-1253927


Aim: The aim of this study was to compare the microtensile bond strength (µTBS) and the characteristics of the adhesive interface of Scotchbond Universal - SU ­ etch-and-rise mode (3M ESPE) and Adper Scotchbond Multi-Purpose - MP (3M ESPE) to dentin over time. Methods: Class I cavity preparations were performed in 60 human molars that were randomly divided according to the dentin bonding system (DBS) used (n=30): (1) Acid conditioning + SU and (2) Acid conditioning + MP. For bonding strength (BS) analysis, 30 teeth (n = 15) were sectioned into sticks and submitted to the microtensile test in a universal testing machine after 24 hours and 12 months. The adhesive interface of the others 30 teeth was analyzed in a confocal microscope after 24 hours and 12 months. The data of µTBS were analyzed by two-way repeated measures ANOVA and Tukey's HSD (α = 0.05). Results: SU presented the lowest DBS compared to MP (p=0.000). Time did not influenced DBS for both adhesive systems (p=0.177). Confocal microscopy analysis showed no cracks between both adhesive systems tested. Conclusion: The results indicate that MP - µTBS showed a better performance compared to SU in total-etch mode

Humans , Dentin-Bonding Agents , Microscopy, Confocal , Dentin , Methacrylates
Braz. j. oral sci ; 20: e211194, jan.-dez. 2021. ilus
Article in English | LILACS, BBO | ID: biblio-1253930


Aim: The aim of this study was to evaluate the effect of ethanol-conditioned dentin on endodontic sealer penetration into dentinal tubules by confocal laser scanning microscopy (CLSM). Methods: Forty human maxillary anterior teeth were instrumented and divided into four groups (n = 10) according to the drying methods: 1) wet: vacuum only, 2) paper points: vacuum + absorbent paper points, (3) 70% ethanol: 70% ethanol (1 min) + vacuum + absorbent paper points, and (4) 100% ethanol: 100% ethanol (1 min) + vacuum + absorbent paper points. All root canals were filled with resin-based endodontic sealer. Four sections from each third (cervical, middle, and apical) were examined by CLSM. Root canal wall perimeter infiltrated by sealer, maximum depth of sealer penetration, percentage of penetrated area, and fluorescence intensity of rhodamine B were measured. Statistical analysis was performed by analysis of variance and Tukey's tests (α = 0.05). Results: No statistical difference was found when percentage of root canal wall coverage infiltrated by sealer were compared. The groups in which ethanol solutions were used presented greater depth of sealer penetration, higher percentage of penetrated area, and higher fluorescence intensity of rhodamine B (p< 0.05) when compared with the wet and paper point groups. Overall, 100% ethanol produced better results than 70% ethanol, except for rhodamine B intensity (cervical third). In addition, the absorbent paper points drying method behaved better than did vacuum only group, except for rhodamine B intensity (apical third). Conclusion: Ethanol-conditioned dentin improved the penetration of resin-based sealer into dentinal tubules, especially at the concentration of 100%

Humans , Wettability , Microscopy, Confocal , Resin Cements , Dentin , Ethanol , Endodontics
Braz. j. oral sci ; 20: e211632, jan.-dez. 2021. ilus
Article in English | LILACS, BBO | ID: biblio-1282550


Non-carious cervical lesions cause destructive dental disorders that actively contribute to the progressive loss of dental structure and the immediate need for dental treatment, due to their multiple symptoms and factors that produce them. Aim: The purpose of the study was to determine the relationship between extrinsic factors and non-carious cervical lesions in patients of the National Hospital Hipólito Unánue. Methods: The research was of a descriptive correlative type. The sample consisted of male and female patients between 18 and 65 years old, who attended the carielogy service of this hospital. For data collection, 2 questionnaires were used to estimate the values of the extrinsic factors that allowed us to obtain the necessary information on the variables to be studied. Spearman's Rho was applied to determine the relationship between the variable's study. Results: According to Spearman's Rho of 0.622, compared to p-0.000 <0.01. Between the variables studied; extrinsic factors and noncarious cervical lesions there is a moderate and significant positive correlation. Conclusion: Through this section it was possible to demonstrate the existing relationship between extrinsic variable factors and non-carious cervical lesions, therefore it was concluded that there is a moderate and significant positive correlation in the sample comprised by the patients of the Hospital in mention

Humans , Male , Female , Tooth Abrasion , Tooth Erosion , Dental Stress Analysis , Dentin , Tooth Wear
Rev. ADM ; 78(4): 195-204, jul.-ago. 2021. ilus, tab
Article in Spanish | LILACS | ID: biblio-1292500


Desde los sesentas, con la invención del vidrio bioactivo, los tratamientos de remineralización se han popularizado entre los cirujanos dentistas y su utilización es cada vez mayor; la remineralización, en conjunto con las adecuadas medidas de higiene preventiva, representa uno de los mejores abordajes mínimamente invasivos y a un costo comparativamente bajo. Este estudio documental tiene por objetivo establecer una mejor comprensión del uso clínico de los biomateriales que inducen la remineralización de la superficie del esmalte dental y dentina. Se realizó una exploración utilizando motores de búsqueda (bases de datos en PubMed, Medigraphic, y Science Direct). El proceso de localización de los estudios relevantes se efectuó introduciendo palabras clave como: silicatos de calcio, fosfopéptidos de caseína-fosfato de calcio amorfo, remineralización, esmalte y dentina, incluyéndose en el procedimiento artículos de antigüedad no superior a siete años, en español e inglés, publicados en revistas científicas aprobadas por pares.Actualmente, no es posible remineralizar del todo la estructura dentaria, por lo cual, en un futuro cercano, los esfuerzos de la odontología de remineralización deben apuntar al desarrollo de agentes biomiméticos inteligentes que restauren al cien por ciento la estructura dental perdida (AU)

Since the sixties, with the invention of bioactive glass, remineralization treatments have become popular among dental surgeons. Their usage is increasing; remineralization, in conjunction with appropriate preventive hygiene measures, represents one of the best minimally invasive treatments at a relatively low cost. This documentary study aims to establish a better understanding of the clinical use of biomaterials that induce remineralization of the surface of teeth enamel and dentin. A search was conducted using search engines (PubMed and Medigraphic databases, and Science Direct). The search process for the relevant studies was carried out by introducing keywords such as calcium silicates, phosphopeptides of amorphous calcium casein-phosphate, remineralization, enamel and dentin, including in the search articles no older than seven years in Spanish and English published in scientific reviewed journals. Currently, it is not possible to completely remineralize the dentary structure so, in the near future, remineralization dentistry efforts should aim to develop (AU)

Humans , Tooth Remineralization/instrumentation , Biocompatible Materials , Dental Enamel/drug effects , Dentin/drug effects , Phosphopeptides/therapeutic use , Caseins , Calcarea Silicata/therapeutic use
Braz. dent. j ; 32(4): 106-115, July-Aug. 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1345518


Abstract The aim of this study was to evaluate the effect of 2% chlorhexidine digluconate (CHX) on microtensile bond strength (µTBS) between an adhesive system and under 3 dentin conditions. For that, this study evaluated the adhesive interface at initial, after 6 months and 1 year of storage. Forty-eight human third molars were prepared and randomly divided into 3 groups, according to dentin substrates: sound dentin (Sd), caries-infected dentin (Ci) and caries-affected dentin (Ca). The groups were subdivided into two according to the dentin pre-treatment: application of 2% CHX or without pre-treatment (control). The dentin surfaces were etched with 35% phosphoric acid gel and bonded with Adper Single Bond 2 (3M ESPE) adhesive system according to manufacturer's instructions. Subsequently, the specimens were stored in deionized water at 37°C for 24h, 6 months and 1 year. Two additional teeth were used to analyze the bonding interfaces by SEM. Data was submitted to three-way ANOVA in a split plot design and Tukey's test (α = 0.05). The results showed that Ci decreased µTBS values when compared to Ca and Sd, regardless storages time or treatment. Stored samples for 6 months and 1 year decreased the µTBS for the control group, but no difference was found between storages time for the CHX group. As a conclusion, the 2% CHX application after etching showed improved dentin bond strength in the storage time, regardless of the substrates evaluated.

Resumo O objetivo deste estudo foi avaliar o efeito do digluconato de clorexidina 2% (CHX) na resistência de união à microtração (µTBS) entre um sistema adesivo e sob 3 condições de dentina. Para tanto, este estudo avaliou a interface adesiva no início, após 6 meses e 1 ano de armazenamento. Quarenta e oito terceiros molares humanos foram preparados e divididos aleatoriamente em 3 grupos, de acordo com os substratos dentinários: dentina hígida (Dh), dentina infectada por cárie (Di) e dentina afetada por cárie (Da). Os grupos foram subdivididos em dois de acordo com o pré-tratamento: aplicação de CHX 2% ou sem pré-tratamento (controle). As superfícies da dentina foram condicionadas com gel de ácido fosfórico a 35%, em seguida, utilizou-se o sistema adesivo Adper Single Bond 2 (3M ESPE) de acordo com as instruções do fabricante. Posteriormente, os corpos-de-prova foram armazenados em água deionizada a 37°C por 24h, 6 meses e 1 ano. Dois dentes adicionais foram usados ​​para analisar as interfaces de união no MEV. Os dados foram submetidos a ANOVA três fatores em esquema de parcela subdividida e ao teste de Tukey (α = 0,05). Os resultados mostram que a Di diminuiu os valores de µTBS quando comparado as Da e Dh, independente do tempo de armazenamento ou tratamento. Amostras armazenadas por 6 meses e 1 ano diminuíram a µTBS para o grupo de controle, mas nenhuma diferença foi encontrada entre o tempo de armazenamento para o grupo CHX. A aplicação de CHX 2% após o condicionamento apresentou melhora na resistência de união à dentina no tempo de armazenamento, independente dos substratos avaliados.

Humans , Dental Bonding , Dentin-Bonding Agents , Tensile Strength , Materials Testing , Composite Resins , Resin Cements , Dentin
Rev. Bras. Saúde Mater. Infant. (Online) ; 21(1): 227-238, Jan.-Mar. 2021. tab, graf
Article in English | LILACS | ID: biblio-1250677


Abstract Objectives: investigate the association between breastfeeding duration and the incidence of severe caries in preschoolers. Methods: a cohort study was conducted with 132 pairs of mothers and children in the city of Diamantina, Brazil. Data collection was performed in 2 moments: when the children were between two and three years of age (baseline- 2013/2014) and after three years (T1-2016/2017). In both moments, children were evaluated for dental caries (International Caries Detection and Assessment System - ICDAS) and a questionnaire was administered to the mothers addressing socioeconomic aspects and thee habits of children. The outcome evaluated was the incidence of severe caries (Dentin caries - ICDAS Codes 5 and 6). Data analysis involved descriptive statistics, chi-squared test and Poisson hierarchical regression with robust variance. Results: children who breastfed for more than 24 months (RR = 2.24 CI95%= 1.23-4.08), those whose parents were separated (RR = 1.73 CI95%= 1.11-2.69), and those with estab-lished/severe caries (RR = 2.74 CI95%= 1.37-5.49) at baseline were at greater risk of incidence of severe caries after three years. Conclusion: breastfeeding for more than 24 months is a risk factor for incidence of severe caries. In addition, family structure and established or severe baseline caries were associated.

Resumo Objetivos: investigar a associação entre a duração da amamentação e a incidência de cárie grave em pré-escolares. Métodos: foi realizado um estudo de coorte com 132 pares de mães e crianças de Diamantina, Minas Gerais, Brasil. As crianças foram avaliadas em dois momentos: dois e três anos de idade (baseline-2013/2014) e após três anos (T1- 2016/2017). Dados socioeconómicos e relativos aos hábitos das criançasforam obtidos por meio de entrevistas com as mães e a presença de cárie dentária foi diagnosticada segundo o protocolo "International Caries Detection and Assessment System - ICDAS". O desfecho foi a incidência de cárie grave (cárie em dentina - códigos ICDAS 5 e 6). Para análise dos dados empregou-se regressão hierárquica de Poisson com variância robusta. Resultados: crianças que amamentaram por mais de 24 meses (RR = 2,24 IC95%= 1,234,08), cujos pais viviam separados no baseline (RR = 1,73 IC95%= 1,11-2,69) e aquelas com cárie estabelecida ou grave no baseline (RR = 2, 74 IC950%= 1,37-5,49) estavam em maior risco de incidência de cárie grave após 3 anos. Conclusão: a amamentação por mais de 24 meses foi um fator de risco para a incidência de cárie dentária grave em pré-escolares. Além disso, estrutura familiar e cárie estabelecida ou grave no baseline estiveram associados.

Humans , Child, Preschool , Socioeconomic Factors , Breast Feeding , Risk Factors , Dental Caries/epidemiology , Dentin , Brazil/epidemiology , Oral Health , Surveys and Questionnaires , Cohort Studies
São Paulo; s.n; 20210219. 201 p.
Thesis in Portuguese | LILACS, BBO | ID: biblio-1147725


Lesões cervicais não cariosas [LCNC] são a perda de tecido dental, esmalte e/ou dentina, próximo da junção amelocementária [JAC], sem a presença de agentes bacterianos cariogênicos. Os dentes pré-molares superiores são os mais frequentemente acometidos. Mais de 90% das lesões estão localizadas na face vestibular dos dentes. Têm etiologia multifatorial, mas o mecanismo de ação dos fatores etiológicos e da interação entre eles ainda não foi claramente elucidada. Apesar da abrasão e a erosão ácida serem os agentes etiológicos mais considerados por muitos anos, eles não são capazes de explicar a ocorrência de lesões subgengivais, nem as que acontecem em um dente isoladamente dos vizinhos. O fator mecânico, que pode atuar isoladamente em um dente, passou a ser investigado como potencial responsável pelas lesões, sozinho ou atuando sinergicamente com a erosão ácida. Uma das possibilidades de interação entre os fatores etiológicos seria o mecanismo conhecido como "stress corrosion crack". Mas existiria uma outra possibilidade: esmalte e dentina podem ser considerados materiais poroelásticos, que apresentam uma fase sólida porosa e uma fase com fluido, livre para se deslocar entre os espaços deixados pela fase sólida. Isto faria que os tecidos dentários funcionassem como esponjas, cada um com sua rigidez específica. Ou seja, poderiam ser capazes de absorver fluido circundante se, ao serem deformados, aumentasse seu volume total. Pelo contrário, expeliriam fluido interno se a deformação ocorresse com diminuição de volume. Estas possibilidades, ao ocorrer com alternância, poderiam gerar o intercâmbio forçado de líquido com o meio externo, além de sua circulação interna forçada, decorrentes das tensões cíclicas a que os dentes estão habitualmente expostos. Se esse líquido fosse ácido, poderia causar desmineralização e perda de substância, o que justificaria a formação das LCNC "desenhadas" especificamente em regiões em que concentra a tensão (ou a deformação). Para avaliar se é válida esta proposta de mecanismo etiológico, foi realizada a presente pesquisa, 100% in silico, dividida em duas partes: 1) estudo do comportamento microestrutural do esmalte e da dentina [micro]; 2) estudo de um dente como macroestrutura poroelástica [macro]. Na parte micro, modelos lineares elásticos 2D representaram a microestrutura, repetida periodicamente, do esmalte e da dentina, visando verificar se a relação entre tensão (de tração ou de compressão) e variação de volume de cada componente microestrutural dos tecidos e o volume seria linear. Assim seria possível verificar se se poderia esperar, ou não, efeitos semelhantes sob carregamentos compressivos ou de tração. Foi avaliado todo o espectro possível de cargas, até a fratura, visando verificar também se haveria alguma não linearidade na relação, que poderia ser devida às características de estruturação dos tecidos, que propiciassem colapso estrutural acima de algum valor de tensão. Na parte macro foi desenvolvido um modelo 2D de primeiro pré-molar superior com características poroelásticas, submetido a três direções de carregamento em relação ao longo eixo: oblíquo (cúspide vestibular); longitudinal cêntrico (no sulco); longitudinal excêntrico (próximo da cúspide vestibular), visando verificar: 1) se existe não linearidade entre magnitude de tensão e volume de fluido "bombeado" (expelido ou absorvido) pelos tecidos; 2) se tanto a tração quanto a compressão têm a mesma capacidade de bombeamento de fluido; 3) se a distribuição do fluido na região cervical, durante o carregamento, seria capaz de desenhar os formatos das lesões, arredondadas ou anguladas. Os resultados das simulações por elementos finitos mostraram que: 1) a relação entre a variação volumétrica de cada uma das fases microestruturais e a tensão média nos modelos é linear, tanto para a dentina quanto para o esmalte. Isto sugere que não exista um valor de tensão abaixo do qual dentina ou esmalte ficariam isentos de LCNC (pois tensões menores ainda poderiam apresentar efeito danoso, caso estivessem presentes com maior frequência), nem haveria um limiar de tensão partir do qual aumentasse a taxa de bombeamento, de modo a exacerbar o mecanismo de formação da LCNC; 2) a taxa de variação volumétrica é igual tanto sob tração como compressão. Isto seria compatível, pelo modelo proposto, com a formação das LCNCs por carregamentos que conduzam tanto à compressão como à tração localizadas, como se verifica na clínica; 3) é possível que a dentina intertubular, apesar de não representar um caminho tão desimpedido quanto os túbulos, seja capaz de bombear os maiores totais de volume de líquido e, por isso, seria a mais envolvida no processo do bombeamento e dissolução. Isto é compatível com o fato de que na superfície de LCNCs ativas sejam encontrados túbulos obliterados e não exista sensibilidade dentinária em muitos casos. A peritubular é a que apresenta menor capacidade de forçar a circulação de fluidos. 4) No esmalte, a região interprismática, como um todo, apresenta uma maior capacidade de bombear fluidos que a região prismática. 5) A relação entre magnitude de tensão e volume bombeado na região cervical pela dentina e pelo esmalte foi linear no estudo macro. Isto significa que não haveria uma tensão limiar a partir da qual a probabilidade de formação de LCNC aumentasse. 6) Tanto a tração quanto a compressão, foram capazes de gerarem bombeamento e, consequentemente provocariam LCNCs, As forças oblíquas para vestibular tendem a gerar tensão de compressão e fluxo com o dobro de volume na face vestibular que na palatina, o que é compatível coma maior incidência de LCNC na vestibular, encontrada clinicamente; 7) O maior volume encontrado no tecido dentinário (JED e dentina situada cervicalmente a ela) concordaria com o achado clínico de que as LCNCs atingem principalmente dentina, preferencialmente ao esmalte. 8) Por ter encontrado que, nos três carregamentos estudados, os volumes bombeados por JED e dentina foram muito semelhantes, poderia se prever que a maior parte das lesões seriam de formato arredondado, na vigência de carregamentos semelhantes.

Dental Enamel , Dentin
Braz. dent. sci ; 24(4, suppl 1): 1-12, 2021. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1352586


Objective: To evaluate the influence of background, substrates and thickness on the color and light behaviour of two ZLS glass ceramics. Material and Methods: Standardized disc-shape specimens (12 x 1.2 mm), color A1 HT, of Celtra Duo and Vita Suprinity (n=30), were tested over a white/black background, and divided in five groups (n=6) to be tested over five substrates (polished gold alloy, white zirconia and composite, dentine and enamel A1 colour). The L*, C*, h*, a*, b* and Δ E values, were recorded in two thicknesses (1.2 and 2.4 mm). Translucency parameter (TP), contrast ratio (CR) and opalescence parameter (OP) were calculated. Data was analysed with non­parametric tests: Mann Whitney between ceramic materials for thickness, Wilcoxon for thicknesses in substrates and ceramic material and Kruskal­Wallis with Bonferroni corrections tests (p<0,01) for substrates. Results: For 2.4 mm, the Δ E values were always higher independently of ceramic material or substrates. Vita Suprinity registered lower values than Celtra Duo. Zirconia substrate registered the lower values. For 1.2 mm, dentine registered the lower values. Gold alloy and composite substrates registered the lower Δ E values for 1.2 mm Celtra Duo and 2.4 mm Vita Suprinity specimens. CT and OP higher values and TP lower values were registered for 2.4 mm Vita Suprinity. It was impossible to calculate for Celtra Duo specimens. Conclusions: Background, substrate and thickness had significant influence in light behaviour and final color of ZLS glass ceramics. Substrates Gold alloy and dentine exhibited clinical acceptable Δ E values for 1.2 mm Celtra Duo specimens. (AU)

Objetivo: Avaliar a influência do fundo, do substrato e da espessura no comportamento da luz e na cor de duas cerâmicas ZLS. Material e métodos: Discos de cerâmica (12 x 1.2 mm) de cor A1 HT, de Celtra Duo e Suprinity (n=30), foram testados sobre fundo branco/preto e cinco substratos (liga Ag-Au-Pt polida; zircónia branca; compósito, dentina e esmalte de cor A1). Os valores L*, C*, h*, a*, b* e Δ E foram registados em duas espessuras (1.2 mm e 2.4 mm). O parâmetro de translucidez (TP), o parâmetro de opalescência (OP) e o índice de contraste (CR) foram determinados. Foram realizados testes não paramétricos: Mann Whitney entre cerâmicas por espessura, Wilcoxon entre categoria de espessura por substrato e cerâmica; Kruskal­Wallis com correção de Bonferroni para substratos (p <0,01). Resultados: Para 2,4 mm, o Δ E foi sempre superior independentemente do material ou substrato. Os valores de Suprinity foram inferiores aos de Celtra Duo. O substrato zirconia obteve o Δ E mais baixo. Para 1,2 mm, a dentina obteve o Δ E mais baixo. A liga dourada e o compósito obtiveram Δ E mais baixo para Celtra Duo 1,2 mm e Suprinity 2,4 mm. Para Suprinity, CT e OP foram maiores para 2,4 mm e menores para TP. Não foi possível calcular para Celtra Duo. Conclusão: O fundo, substrato e espessura tiveram influência significativa no comportamento da luz e cor das restaurações de cerâmica ZLS. Apenas os substratos metal e dentina apresentaram valores clinicamente aceitáveis, para Celtra Duo na espessura de 1.2 mm.(AU)

Color , Composite Resins , Dental Enamel , Dental Materials , Dentin
Braz. dent. sci ; 24(4, suppl 1): 1-9, 2021. tab, ilus
Article in English | LILACS, BBO | ID: biblio-1352595


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)

Water Storage , Dentin-Bonding Agents , Dental Enamel , Dentin
Braz. oral res. (Online) ; 35: e012, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1132751


Abstract The purpose of this study was to analyze the effect of the application of different concentrations of EDTA on the adhesion of fiber posts to root dentin using self-adhesive resin cements. After endodontic treatment, 78 single roots were randomly divided into six groups (n = 13) according to the combination of the following factors: surface dentin treatment - control (distilled water), 17% EDTA and 24% EDTA; and self-adhesive resin cement - RelyX U200 (RX); and Multilink Speed (ML). After fiber post cementation, six slices were obtained for each root. Ten roots of each group were used for bond strength (BS) and three for microhardness (MH) evaluations. Data obtained from BS and MH tests for each resin cement were subjected to two-way ANOVA (surface treatment vs. root region) and to a post-hoc Tukey's test (α = 0.05). The lowest BS value was observed in the 24% EDTA group for RX cement, whereas the highest values for ML cement were observed for the control group in the middle and apical regions. In the MH test, the lowest value for RX was observed for 24% EDTA in the cervical region, whereas and the highest value for the ML cement was observed in the control group. Regarding both self-adhesive resin cements tested, the application of 24% EDTA was not able to improve the adhesion of fiber posts to root canal.

Resin Cements , Materials Testing , Post and Core Technique , Edetic Acid/pharmacology , Dental Pulp Cavity , Dentin , Glass
Braz. oral res. (Online) ; 35: e29, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1153613


Abstract This study evaluated how Er,Cr:YSGG laser, associated or not with 5% fluoride varnish, influences the surface roughness and volume loss of bovine root dentin submitted to erosive and/or abrasive wear. One hundred and twenty dentin specimens were divided into the groups: without preventive treatment (WPT), 5% fluoride varnish (FV); Er,Cr:YSGG laser irradiation (L), and varnish combined with laser (FV + L). The specimens (n = 10) were subdivided into: 1 = erosion (E); 2 = abrasion (A); and 3 = erosion followed by abrasion (E + A). The erosive solution used was a soft-drink (pH = 2.42 at 4ºC) applied in 5-min cycles twice a day for 10d. Abrasive wear involved brushing for 60s with an electric brush (1,600-oscillations/s) at a load of 2.0N. Surface roughness and volume loss were evaluated using a laser scanning confocal microscope. Roughness data were submitted to one-way ANOVA and Tukey post-hoc test. For volume loss, the Kruskal-Wallis and Dunn's post-hoc tests were used (α = 5%). The lowest values of roughness were found in the control areas of all subgroups (p > 0.05). In the experimental area, the [(WPT) + (E+A)] subgroup had a significantly higher roughness (5.712 ± 0.163 μm 2 ) than the other subgroups (p < 0.05). The L and (FV + L) groups had statistically similar roughness, regardless of the type of wear. The (FV + L) group had the lowest volume loss, regardless of the type of wear performed: [(FV + L) + (E)] = 7.5%, [(FV + L) + (A) = 7.3%, and [(FV + L) + (E + A)] = 8.1%. The subgroup [(WPT) + (E + A)] had the highest volume loss (52.3%). The proposed treatments were effective in controlling dentin roughness. Laser irradiation can be an effective method to increase root dentin resistance after challenges and limit problems related to non-carious lesions.

Animals , Cattle , Tooth Erosion/etiology , Lasers, Solid-State/therapeutic use , Tooth Root , Toothbrushing , Dentin , Fluorides
Braz. dent. sci ; 24(3): 1-10, 2021. tab, ilus, graf
Article in English | LILACS, BBO | ID: biblio-1282057


Objective: The aim of this study was to analyze mechanical and thermal stresses of hybrid ceramic and lithium disilicate based ceramic of CAD/CAM inlays using 3D Finite element analysis. Material and Methods:A three dimensions finite element model of permanent maxillary premolar designed according to standard anatomy with class II cavity preparation for inlay restored with two different ceramic materials: 1- Hybrid ceramic (Vita Enamic), 2- Lithium disilicate based ceramic (IPS e.max CAD). Totally six runs were performed on the model as: One loading case for each restorative material was tested in stress analysis; seven points of loading with 140N vertically applied at palatal cusp tip and cusp slop, marginal ridges and central fossa while the models base was fixed as a boundary condition in the two cases. Two thermal analysis cases were performed for each restoration material by applying 5ºC and 55ºC on the crown surface including the restoration surface. Results:The results of all structures were separated from the rest of the model to analyze the magnitude of stress in each component. For each group, maximum stresses on restorative materials, cement, enamel, and dentin were evaluated separately. Both ceramic materials generated similar stress distribution patterns for all groups when a total occlusal load of 140 N was applied. Conclusion: Thermal fluctuations of temperature have a great influence on the stresses induced on both restoration and tooth structure. IPS e.max CAD produced more favorable stresses on the tooth structure than Vita Enamic. (AU)

Objetivo: O objetivo deste estudo foi analisar o estresse mecânico e térmico de inlays de cerâmica hibrida e a base de dissilicato de lítio através da análise em 3D de elementos finitos. Material e Métodos: Foi realizado o design de um modelo de três dimensões em elementos finitos de um pré-molar superior de acordo com os padrões anatômicos de um preparo de cavidade classe II para restauração de inlay em dois tipos de cerâmicas diferentes: 1 Cerâmica hibrida (Vita Enamic), 2 ­ Cerâmica a base de dissilicato de lítio (IPS e.max CAD). No total, seis execuções foram realizadas no modelo como: Uma carga para cada material restaurador foi testado para análise de tensão; sete pontos de carga com 140N foi aplicado verticalmente na ponta da cúspide palatina, saliência da cúspide, cristas marginais e fossa central enquanto a base do modelo foi fixada como uma condição de limite nos dois casos. Duas análises térmicas foram realizadas para cada material de restauração, aplicando 5ºC e 55ºC na superfície da coroa, incluindo a superfície da restauração. Resultados: Os resultados de todas as estruturas foram separados do resto do modelo para analisar a magnitude do estresse de cada componente. Para cada grupo, o máximo de estresse nos materiais restauradores, cemento, esmalte e dentina foram avaliados separadamente. Padrões similares de distribuição de estresse foram gerados em todos os grupos para ambos os materiais cerâmicos, quando a carga oclusal de 140 N foi aplicada. Conclusão: As variações térmicas de temperatura têm uma grande influência nas tensões induzidas na restauração e na estrutura dentária. IPS e.max CAD produziu tensões mais favoráveis na estrutura dentária do que o Vita Enamic (AU)

Bicuspid , Finite Element Analysis , Dental Cavity Preparation , Dental Cementum , Dental Enamel , Dentin
J. appl. oral sci ; 29: e20200266, 2021. tab, graf
Article in English | LILACS | ID: biblio-1180799


Abstract Objectives We analyzed the effects of the Er:YAG laser used with different parameters on dentinal tubule (DT) occlusion, intrapulpal temperature and pulp tissue morphology in order to determine the optimal parameters for treating dentin hypersensitivity. Methodology Dentin specimens prepared from 36 extracted human third molars were randomized into six groups according to the treatment method (n=6 each): control (A); Gluma desensitizer (B); and Er:YAG laser treatment at 0.5 W , 167 J/cm2 (50 mJ, 10 Hz) (C), 1 W , 334 J/cm2 (50 mJ, 20 Hz) (D), 2 W , 668 J/cm2 (100 mJ, 20 Hz) (E), and 4 W and 1336 J/cm2 (200 mJ, 20 Hz) (F). Treatment-induced morphological changes of the dentin surfaces were assessed using scanning electron microscopy (SEM) to find parameters showing optimal dentin tubule occluding efficacy. To further verify the safety of these parameters (0.5 W, 167 J/cm2), intrapulpal temperature changes were recorded during laser irradiation, and morphological alterations of the dental pulp tissue were observed with an upright microscope. Results Er:YAG laser irradiation at 0.5 W (167 J/cm2) were found to be superior in DT occlusion, with an exposure rate significantly lower than those in the other groups (P<0.05). Intrapulpal temperature changes induced by Er:YAG laser irradiation at 0.5 W (167 J/cm2) with (G) and without (H) water and air cooling were demonstrated to be below the threshold. Also, no significant morphological alterations of the pulp and odontoblasts were observed after irradiation. Conclusion Therefore, 0.5 W (167 J/cm2) is a suitable parameter for Er:YAG laser to occlude DTs, and it is safe to the pulp tissue.

Humans , Lasers, Solid-State/therapeutic use , Microscopy, Electron, Scanning , Dental Occlusion , Dentin
J. appl. oral sci ; 29: e20200511, 2021. tab, graf
Article in English | LILACS, BBO | ID: biblio-1143152


Abstract Objective To evaluate the effect of the association between external and internal tooth bleaching on color changes in dentin and enamel, individually or recombined, previously stained with triple antibiotic paste (TAP). Methodology Forty enamel-dentin specimens from bovine incisors were separated into ten blocks according to similarity in their whiteness index (WID). Three specimens within each block were stained by dentin exposure to TAP, and the remaining specimen was used as control to estimate color changes. Specimens were sectioned to separate tissues, and dentin and enamel colors were measured individually and after being recombined. Alterations in color (CIEDE2000 - ΔE00) and translucency parameter (TP) resulting from staining were estimated by color difference between stained and control specimens. The contribution of each tissue to the color change (CTCC) was also calculated. Non-sectioned stained specimens were bleached by applying sodium perborate on dentin, associated or not with 35% hydrogen peroxide on enamel. Color changes caused by bleaching procedures were estimated and data were analyzed using the paired t-test or Two-way repeated measures ANOVA. Results TAP caused more pronounced changes in dentin, but enamel color was also affected. Both protocols presented a similar ΔE00, and dentin showed the greater color change. After exposure to TAP, we observed a reduction in WID; WID values were the same for bleached and control specimens regardless of protocol. We found no significant effect of substrate and bleaching technique on TP. Enamel played a more critical role in color changes caused by either staining or bleaching procedures. Conclusion Enamel color played a greater role on tooth color changes than dentin. External and internal bleaching association did not improve bleaching effect on specimens stained with TAP.

Animals , Cattle , Color , Dental Enamel , Dentin , Tooth Bleaching Agents , Tooth Bleaching , In Vitro Techniques , Hydrogen Peroxide
J. appl. oral sci ; 29: e20200736, 2021. graf
Article in English | LILACS | ID: biblio-1180797


Abstract Objective To evaluate the efficacy of Nd:YAG laser associated with calcium-phosphate desensitizing pastes on dentin permeability and tubule occlusion after erosive/abrasive challenges. Methodology Dentin specimens were exposed to 17% ethylene diamine tetra-acetic acid (EDTA) solution for 5 min and randomly allocated into five groups: G1, control (no treatment); G2, Nd:YAG laser (1 W, 10 Hz, 100 mJ, 85 J/cm2); G3, Laser + TeethmateTM Desensitizer; G4, Laser + Desensibilize Nano P; and G5, Laser+Nupro®. Specimens underwent a 5-day erosion-abrasion cycling. Hydraulic conductance was measured post-EDTA, post-treatment, and post-cycling. Post-treatment and post-cycling permeability (%Lp) was calculated based on post-EDTA measurements, considered 100%. Open dentin tubules (ODT) were calculated at the abovementioned experimental moments using scanning electron microscopy and ImageJ software (n=10). Data were analyzed using two-way repeated measures ANOVA and Tukey's test (α=0.05). Results G1 presented the highest %Lp post-treatment of all groups (p<0.05), without significantly differences among them. At post-cycling, %Lp significantly decreased in G1, showed no significant differences from post-treatment in G3 and G4, and increased in G2 and G5, without significant differences from G1 (p>0.05). We found no significant differences in ODT among groups (p>0.05) post-EDTA. At post-treatment, treated groups did not differ from each other, but presented lower ODT than G1 (p<0.001). As for post-cycling, we verified no differences among groups (p>0.05), although ODT was significantly lower for all groups when compared to post-EDTA values (p<0.001). Conclusion All treatments effectively reduced dentin permeability and promoted tubule occlusion after application. Combining Nd YAG laser with calcium-phosphate pastes did not improve the laser effect. After erosive-abrasive challenges, treatments presented no differences when compared to the control.

Lasers, Solid-State/therapeutic use , Dentin Desensitizing Agents , Microscopy, Electron, Scanning , Calcium/pharmacology , Dentin , Dentin Permeability
J. appl. oral sci ; 29: e20200859, 2021. graf
Article in English | LILACS | ID: biblio-1286923


Abstract Introduction Due to its ability to arrest untreated dental caries, silver diamine fluoride (SDF) has been advocated for indirect pulp capping procedures. However, the high concentrations of silver and fluoride in SDF raise concerns about its biocompatibility to pulpal tissues. Objectives This study aimed to investigate the effect of SDF on the viability, alkaline phosphatase (ALP) activity, and morphology of pulpal-like cells (RPC-C2A) and to evaluate the influence of reduced glutathione (GSH) on SDF-induced cytotoxicity and deposit formation on dentin. Methodology The cytotoxicity of diluted 38% SDF solutions (10-4 and 10-5), with or without the addition of 5 mM or 50 mM GSH, was evaluated at 6 and 24 hours. Cell viability was detected using WST-8 and the effect on ALP activity was performed using an ALP assay kit. Cell morphology was observed using a phase-contrast microscope. Scanning electron microscopy analysis was conducted to evaluate the effect of GSH incorporation or conditioning on SDF-induced deposit formation on dentin discs. Cytotoxicity data were analyzed by two-way analysis of variance (ANOVA) and Tukey post hoc tests (p<0.05). Results There were significant differences between the groups. The results demonstrated that all tested SDF dilutions caused a remarkable cytotoxic effect, while the addition of GSH prevented SDF-induced damage at 6-hour exposure time in the higher dilution of SDF. Dentin treated with plain SDF or GSH-incorporated SDF solution showed deposit formation with occluded dentinal tubules, unlike the other groups. Conclusion SDF severely disturbed the viability, mineralization-ability, and morphology of pulpal-like cells, while controlled concentrations of GSH had a short-term protective effect against SDF-induced damage. GSH showed an inhibitory effect on SDF-induced dentinal deposit formation. Further research is warranted to evaluate the effect of GSH on caries-arresting, anti-hypersensitivity, and antibacterial functions of SDF.

Animals , Rats , Dental Caries , Cariostatic Agents/toxicity , Fluorides, Topical/toxicity , Silver Compounds , Dentin , Glutathione , Quaternary Ammonium Compounds
J. appl. oral sci ; 29: e20210081, 2021. tab, graf
Article in English | LILACS | ID: biblio-1340099


Abstract Objective To evaluate the effect of a toothpaste containing calcium silicate/sodium phosphate/fluoride associated or not to the boost serum (BS) against erosive tooth wear (ETW) on enamel and dentin. Methodology Bovine enamel and dentin specimens were subjected to an erosion-abrasion cycling model (1% citric acid - pH 3.6 -2 min / artificial saliva - 60 min, 4×/day, 5 days). Toothbrushing was performed for 15 s (2 min exposed to slurry), 2×/day, with the toothpastes (n=10): control without fluoride (Weleda), Arg/Ca/MFP (Colgate Pro-Relief), Si/PO4/MFP (Regenerate-Unilever), and Si/PO4/MFP/BS (Si/PO4/MFP with dual BS - Advanced Enamel Serum-Unilever). The effect of treatments on the eroded tissues was assessed by surface microhardness in the first day, and surface loss (SL) resulting from ETW was evaluated by profilometry (μm) after three and five days. Additional dentin specimens (n=5/group) were subjected to 20,000 brushing cycles to verify the abrasivity of the toothpastes. Data were subjected to ANOVA and correlation tests (5%). Results For enamel, no difference in microhardness was observed among the treated groups, and similar SL was obtained after 5 days. For dentin, Si/PO4/MFP/BS resulted in higher microhardness values, but none of the groups presented significantly lower SL than the control. There was no significant correlation between SL and abrasiveness. Conclusion The calcium silicate/sodium phosphate toothpaste and serum increased microhardness of eroded dentin, but they did not significantly reduce enamel and dentin loss compared to the non-fluoride control toothpaste. The abrasiveness of the toothpastes could not predict their effect on ETW.

Animals , Cattle , Toothpastes , Fluorides , Phosphates , Silicates , Calcium Compounds , Dental Enamel , Dentin
Rev. Fac. Odontol. (B.Aires) ; 36(83): 35-40, 2021. ilus, tab
Article in Spanish | LILACS | ID: biblio-1342884


El secado es uno de los factores clave para lograr una adhesión micromecánica exitosa en la dentina con los sistemas adhesivos de grabado independiente. El objetivo de este trabajo fue comparar los residuos remanentes luego de cuatro procedimientos diferentes de secado en preparaciones ex vivo en dentina. Se utilizaron cinco terceros molares ex-vivo, en cada uno de los cuales se realizó una preparación dentinaria en piso y paredes con al menos un socavado. Las unidades experimentales fueron almacenadas en solución fisiológica durante 7 días. Las distintas técnicas de secado (G1- G8) se aplicaron, luego de que las preparaciones fueron tratadas con gel de ácido fosfórico al 37% (Blue Gel etch Megadental) durante 15s y lavadas con jeringa y agua a presión durante 15s (Técnica de Grabado Ácido o TGA), de la siguiente manera: algodón común (Condesa) (G1), papel tisú (Achiss) cortado a mano (G2) y con tijera (G3), esponja (Sharpys) (G4), papel tisú (Simplicity) cortado a mano (G5)(AU)

Waste Products , Dentin/drug effects , Acid Etching, Dental , Dental Bonding , Air Abrasion, Dental , Dental Cavity Preparation