Dentin permeability after pretreatment with titanium tetrafluoride and self-etching or universal adhesive systems

Aim: To evaluate dentin permeability after pretreatment with 2.5% aqueous solution of titanium tetrafluoride (TiF4), followed by a self-etching universal adhesive system. Methods: Forty dentin discs (1.5 mm thick) were randomly divided into groups according to the application or non-application of a pretreatment, and the type of adhesive system to be tested (two-step self-etching/ Clearfil SE Bond/ Kuraray Medical, or universal adhesive system/ Single Bond Universal/ 3M ESPE). Both sides of the discs were conditioned with 37% phosphoric acid to remove the smear layer. The first hydraulic conductivity measurement (L1) was performed in a permeability machine, under 5 PSI pressure. The samples were sanded again to form a standardized smear layer. The teeth designated for pre-treatment with TiF4 received the TiF4 solutions applied actively for 60 seconds, and the adhesive systems were applied according to the manufacturer's instructions. Then, a new hydraulic conductivity measurement (L2) was performed for the purpose of calculating the hydraulic conductance at a later time, considering the water viscosity and the thickness of the specimen. The percentage (L) of dentin permeability after application of the adhesive system was obtained (L (%) = [(L1-L2) x100] / L1). The Mann-Whitney non-parametric test was applied. Results: There was no difference between the two adhesive systems, or between the groups with or without pretreatment, as regards dentin permeability (p>0.05). Conclusion: Pretreatment with 2.5% TiF4 did not influence dentin permeability, irrespective of the adhesive system used

Bonding strategy of a universal adhesive system containing chitosan: influence on dentin permeability, and effect on adhesive layer micromorphology / Estratégia de união de um sistema adesivo universal contendo quitosana: influência na permeabilidade dentinária e efeito na micromorfologia da camada do adesivo

ABSTRACT Aim: This study evaluated the influence of chitosan added to a universal adhesive system used in totaletch (TE) or self-etch (SE) mode on dentin permeability, and on the micromorphology of the adhesive layer. Materials and Method: Dentin discs were obtained from human third molars and randomly distributed according to bonding strategy (TE or SE), and to whether or not 1% chitosan (C) was added to a universal adhesive system (Single Bond Universal/3M ESPE), to create the following groups (n=10): TE, TEC, SE, and SEC. Dentin permeability was measured at baseline and after application of dentin treatments. The surface of the adhesive layer (AL) and the dentin adjacent to the AL were examined under a scanning electron microscope. Results: There were no significant differences in permeability percentage between the groups with and without C (TE and SE versus TEC and SEC) (p>0.05; Mann Whitney test). Dentin permeability was lower when the adhesive system was applied in the SE mode, regardless of the addition of C. The micromorphology of the AL surface showed irregularities, and a greater degree of porosity, when the adhesive system was applied in the SE mode, regardless of chitosan addition. There was a greater depth of penetration of the adhesives into the dentin adjacent to the AL in both the TE and TEC groups. Chitosan added to the adhesive system did not influence dentin permeability. Conclusions: The self-etch strategy led to lower dentin permeability, and to more irregularities on the surface of the adhesive layer.

RESUMO Objetivo: Este estudo avaliou a influência da quitosana adicionada a um sistema adesivo universal usado no modo total-etch (TE) ou self-etch (SE) na permeabilidade dentinária e na micromorfologia da camada adesiva. Materiais e método: Discos de dentina foram obtidos de terceiros molares humanos e distribuídos aleatoriamente de acordo com a estratégia de união (TE ou SE), e para incorporação ou não de quitosana a 1% (Q) em um sistema adesivo universal (Single Bond Universal/3M ESPE), para obter os seguintes grupos (n=10): TE, TEQ, SE e SEQ. A permeabilidade da dentina foi medida no início e após a aplicação dos tratamentos de dentina. A superfície da camada adesiva (CA) e a dentina adjacente à CA foram examinadas em microscópio eletrônico de varredura. Resultados: Não houve diferenças significativas no percentual de permeabilidade entre os grupos com e sem Q (TE e SE versus TEQ e SEQ) (p>0,05; teste de Mann Whitney). Houve um menor percentual de permeabilidade dentinária quando o sistema adesivo foi aplicado no modo SE, independentemente da incorporação de Q. A micromorfologia da superfície da CA apresentou irregularidades e maior grau de porosidade quando o sistema adesivo foi aplicado no modo SE, independentemente da adição de Q. Houve maior profundidade de penetração dos adesivos na dentina adjacente à CA nos grupos TE e TEQ. A quitosana adicionada ao sistema adesivo não influenciou a permeabilidade dentinária. Conclusões: A estratégia autocondicionante levo

Effect of different toothpastes on permeability and roughness of eroded dentin / Efeito de diferentes cremes dentais na permeabilidade e rugosidade da dentina erodida

ABSTRACT Dentin hypersensitivity (DH) is characterized by rapid, acute pain arising from exposed dental tubules. Aim: the aim of this study was to evaluate the roughness, tubule occlusion, and permeability of eroded dentin brushed with different toothpastes. Materials and Method: ninety bovine teeth were cut into blocks. Thirty hemifaces were protected with varnish and the other sixty were submitted to permeability tests. Specimens were divided into groups according to the dentifrices: without fluoride (WF), sodium fluoride (NaF), and stannous fluoride (SnF2). The blocks were subjected to a 5-day erosive-abrasive protocol. Surface roughness and dentinal tubule occlusion (n=10) were assessed for both control and test hemifaces of the same sample along with permeability analysis (n=20). Two-way RM ANOVA and Tukey's post-hoc test were performed (p≤0.05). Results: NaF and SnF2 presented higher roughness than WF. The number of open tubules was higher in WF. Permeability was higher in SnF2, but there was no significant difference between WF and NaF. Conclusions: both fluoride toothpastes occluded dentinal tubules and increased roughness. NaF toothpaste promoted greater decrease in dentin permeability.

RESUMO A hipersensibilidade dentinária (HD) é caracterizada por dor rápida e aguda decorrente de túbulos dentais expostos. Objetivo: este estudo teve como objetivo avaliar a rugosidade, oclusão tubular e permeabilidade da dentina erodida escovada com diferentes dentifrícios. Materiais e Método: noventa dentes bovinos foram seccionados em blocos. Trinta hemifaces foram protegidas com verniz e outras sessenta foram submetidas à permeabilidade. Os espécimes foram divididos em grupos de acordo com os dentifrícios: sem flúor (SF), fluoreto de sódio (NaF) e fluoreto estanoso (SnF2). Em seguida, os blocos foram submetidos a um protocolo erosivo-abrasivo de 5 dias. A rugosidade da superfície e a oclusão do túbulo dentinário (n = 10) foram avaliadas para ambas as hemifaces de controle e teste da mesma amostra, também realizou-se a análise de permeabilidade (n = 20). Two-way RM ANOVA e pós-teste de Tukey foram realizados (p≤0,05). Resultados: NaF e SnF2 apresentaram rugosidade superior ao SF. O número de túbulos abertos foi maior em SF. Não encontramos diferenças significativas entre SF e NaF em relação à permeabilidade; entretanto, SnF2 apresentou maior permeabilidade. Conclusão: ambos os dentifrícios fluoretados foram capazes de ocluir os túbulos dentinários e aumentar a rugosidade. No entanto, o dentifrício NaF promoveu uma maior diminuição da permeabilidade dentinária.

Physicochemical properties and penetration into dentinal tubules of calcium hypochlorite with surfactants

Abstract The aim was to assess the physicochemical properties and the penetration into dentinal tubules of calcium hypochlorite solution [Ca(OCl)2], with or without surfactants. The surfactants benzalkonium chloride, cetrimide, Tween 80 and Triton X-100 were mixed at different concentrations with sodium hypochlorite solution (NaOCl), Ca(OCl)2 and distilled water (control). Once the critical micellar concentration (CMC) of the surfactants in Ca(OCl)2 and NaOCl was determined, pH, free chlorine, surface tension and free calcium ions were evaluated. The penetration into dentinal tubules of NaOCl and Ca(OCl)2, with or without benzalkonium chloride and Triton X-100 [surfactants that promoted the lowest surface tension of Ca(OCl)2], was assessed using human premolars stained with crystal violet. The statistical tests were one-way ANOVA and Tukey's post-test, Kruskal-Wallis and Dunn's post-test, two-way ANOVA and Bonferroni's post-test, and t-test; depending on the assay. The addition of surfactants reduced the surface tension of NaOCl and Ca(OCl)2, and did not alter the pH or the free available chlorine of either solution. The addition of all surfactants increased the availability of free calcium ions in Ca(OCl)2, especially benzalkonium chloride. Ca(OCl)2 exhibited lower penetration into dentinal tubules than NaOCl, and the addition of surfactants did not improve the penetration of Ca(OCl)2, but did increase the penetration of NaOCl. It can be concluded that the addition of surfactants to Ca(OCl)2 did not increase the penetration into dentinal tubules, but it did promote lower surface tension, without changing the pH or free available chlorine values, and higher availability of free calcium ions in Ca(OCl)2.

Resumo O objetivo foi avaliar as propriedades físico-químicas e a penetrabilidade nos túbulos dentinários da solução de hipoclorito de cálcio [Ca(OCl)2], com ou sem surfactantes. Os surfactantes cloreto de benzalcônio, cetrimida, Tween 80 e Triton X-100 foram misturados em diferentes concentrações com a solução de hipoclorito de sódio (NaOCl), Ca(OCl)2 e água destilada (controle). Uma vez determinada a concentração micelar crítica (CMC) dos surfactantes em Ca(OCl)2 e NaOCl, foram avaliados o pH, cloro livre, tensão superficial e íons de cálcio livre. A penetrabilidade nos túbulos dentinários de NaOCl e Ca(OCl)2, com ou sem cloreto de benzalcônio e Triton X-100 [surfactantes que promoveram a menor tensão superficial de [Ca(OCl)2] foi avaliada utilizando pré-molares humanos corados com cristal violeta. Os testes estatísticos foram ANOVA de uma via e pós-teste de Tukey, Kruskal-Wallis e pós-teste de Dunn, ANOVA de duas vias e pós-teste de Bonferroni, e teste t; dependendo do ensaio. A adição de surfactantes reduziu a tensão superficial do NaOCl e Ca(OCl)2, e não alterou o pH ou cloro livre das soluções. A adição de todos os surfactantes aumentou a disponibilidade de íons de cálcio livre de Ca(OCl)2, principalmente o cloreto de benzalcônio. Ca(OCl)2 apresentou menor penetrabilidade nos túbulos dentinários do que NaOCl, e a adição de surfactantes não aumentou a penetrabilidade de Ca(OCl)2, mas aumentou a penetrabilidade de NaOCl. Pode-se concluir que a adição de surfactantes no Ca(OCl)2 não aumentou a penetrabilidade nos túbulos dentinários, mas promoveu menor tensão superficial, sem alterar os valores de pH ou cloro livre, e maior disponibilidade de íons de cálcio livre em Ca(OCl)2.

S-PRG-based toothpastes compared to NaF toothpaste and NaF varnish on dentin permeability in vitro

Abstract Objectives To analyze the effect of 5 toothpastes containing different percentages of S-PRG fillers compared to NaF toothpaste and NaF varnish on the dentin hydraulic conductance (Lp). Methodology Dentin disks (1.0±0.2 mm thickness) were cut from third molars, and their Lp values were evaluated using Flodec. The specimens were allocated into 7 groups (n=8). The minimum (smear layer) and the maximum (after acid etching) Lp values were recorded. Lp was also assessed after treatment with either a 0wt.%, 1wt.%, 5wt.%, 20wt.%, or 30wt.% S-PRG toothpaste, a NaF toothpaste, or a NaF varnish. Toothpastes were applied by brushing for 15 s, allowing it to settle for 1 min, and rinsing with deionized water. The NaF varnish was applied for 4 min and was removed with a probe. Specimens were exposed to citric acid (6%, pH 2.1, 1 min) and their final Lp was recorded. The pH of all products was recorded (n=3) and specimens from each group were analyzed by Laser Scanning Confocal Microscopy (LSCM). Data were subjected to 2-way repeated measures ANOVA and post-hoc Bonferroni (a=0.05). Results The highest Lp reduction was noticed for the 5wt.% S-PRG toothpaste, NaF toothpaste, and NaF varnish. However, the toothpastes containing 5wt.%, 20wt.%, and 30wt.% of S-PRG were similar to all toothpastes but differed from the NaF varnish. After erosion, all groups retrieved their maximum Lp values, except for the NaF varnish. The LSCM evidenced deposits on the surface of specimens treated with 5%, 20%, and 30% S-PRG-based toothpastes and NaF toothpaste. Even more deposits were observed for the NaF varnish. After the erosive challenge, the deposits were diminished in all groups. Conclusion Toothpastes containing 5wt.%, 20wt.%, and 30wt.% of S-PRG fillers behaved similarly to a conventional NaF toothpaste, even after an erosive challenge. The NaF varnish promoted better reduction of the Lp, but its effect was also diminished after erosion.

Assessment of permeability of eroded dentin after the use of universal, self-etch, and conventional systems / Avaliaçao da permeabilidade da dentina com erosao, após o uso de sistemas universais, autocondicionantes e convencionais

ABSTRACT Dentin hypersensitivity is caused by increased dentinal permeability due to total or partial exposure of dentinal tubules, which in turn can be produced by alterations of dental structures or failure of restorative procedures. The purpose of this in vitro study was to evaluate the efficacy of the application of different kinds of adhesive systems to prevent dentin permeability before and after an erosive challenge. Fifty bovine dentin discs (6x1 mm) were prepared and the specimens were divided into 5 groups (n=10): (SB2) Single Bond 2, (SBU) Universal Single Bond, (CSB) Clearfil SE Bond, (SM) Scotchbond Multipurpose and (C) Control. Hydraulic conductance of dentin was recorded after adhesive application (HC-1) and after erosive challenge (HC-2). Dentin surface images of post-treatment and post-erosive challenge were obtained by scanning electron microscopy (SEM). Data were analyzed using Kruskal Wallis, Mann-Whitney with Bonferroni correction and Wilcoxon tests (p<0.05). Reduction in dentin permeability was observed with the application of adhesive systems (p<0.05). After the erosive challenge, dentin permeability increased for SBU and CSB (p<0.05), while SB2 and SM did not differ in HC-1 or HC-2 (p>0.05). The conventional, self-etching and universal adhesive systems reduce dentinal permeability by more than 80%, and dentin demineralization may contribute to the increased permeability of universal and self-etching systems.

RESUMO Diversos pacientes apresentam hipersensibilidade dentaria ou falha nos procedimentos restauradores, devido á exposigao total ou parcial de túbulos dentinários. O objetivo deste estudo in vitro foi o de avaliar a influencia da aplicagao de diferentes tipos de sistemas adesivos na permeabilidade da dentina e após o desafio erosivo. Cinquenta discos de dentina bovina (6x1 mm) foram confeccionados e os espécimes foram divididos em 5 grupos (n = 10): (SB2) Single Bond 2, (SBU) Universal Single Bond, (CSB) Clearfil SE Bond, (SM) ScotchbondMultiuso e (C) Controle. A condutáncia hidráulica da dentina foi registrada após a aplicagao do adesivo (HC-1) e após o desafio erosivo (HC-2). Imagens da superficie da dentina de pós-tratamento e pós-desafio erosivo foram obtidas por microscopia eletronica de varredura (MEV). Os dados foram analisados pelos testes de Kruskal Wallis, Mann-Whitney com correçâo de Bonferroni e Wilcoxon (p <0,05). Reduçâo da permeabilidade dentinária foi observada com a aplicaçâo dos sistemas adesivos (p <0,05). Após o desafio erosivo, a permeabilidade dentinária aumentou para SBU e CSB (p <0,05), enquanto SB2 e SM nao diferiram em HC-1 e HC-2 (p> 0,05). Os sistemas adesivos convencionais, autocondicionantes e universais reduzem a permeabilidade dentinária em mais de 80%, e a dentina desmineralizada pode gerar um aumento da permeabilidade dos sistemas adesivos universais e autocondicionantes.

Analysis of permeability and biological properties of dentin treated with experimental bioactive glasses / Análise da permeabilidade e propriedades biológicas da dentina tratada com vidros bioativos experimentais

O objetivo deste estudo foi avaliar a capacidade obliteradora de diferentes agentes dessensibilizantes em dentina humana através da mensuração da permeabilidade dentinária, e suas performances biológicas através da análise de citotoxicidade em fibroblastos gengivais humanos. Cinquenta molares humanos foram utilizados, dos quais foram obtidos blocos de dentina (4x4x1mm) posteriormente distribuídos em grupos de acordo com o dessensibilizante a ser utilizado (n=10): Grupo 1 - Controle (Saliva artificial. Sem aplicação de agente dessensibilizante); Grupo 2 - Ultra EZ (Ultradent); Grupo 3 - Desensibilize Nano P (FGM); Grupo 4 - Vidro Bioativo T5-OH (solução experimental); Grupo 5 - Vidro Bioativo F18 (solução experimental). Os tratamentos dessensibilizantes foram realizados durante 15 dias. Além disso, os espécimes foram submetidos ao desafio com ácido cítrico para simular condições desmineralizantes do ambiente oral. As amostras foram submetidas à análise de permeabilidade antes e após os procedimentos dessensibilizantes e o desafio ácido. Análise de citotoxicidade foi realizada pelo ensaio Alamar Blue complementado pela quantificação de proteína pelo Método BCA (ácido bicinconínico) (N=3; n=3) nos tempos de avaliação de 15 minutos, 24 horas e 48 horas. Microscopia eletrônica de varredura (MEV) e Espectroscopia de Raio-X por Energia Dispersiva (EDS) foram realizadas para análise qualitativa da dentina tratada. Dados de permeabilidade dentinária foram analisados por ANOVA dois fatores medidas repetidas e Teste de Tukey (α=0,05). Para a citotoxicidade, foram utilizados os testes Kruskal-Wallis e Newman-Keuls (α=0,05). Os resultados mostraram que para a permeabilidade dentinária não houve diferença significante entre os agentes dessensibilizantes após os tratamentos (p> 0,05), porém o grupo controle apresentou os maiores valores (0,131 ± 0,076 Lp, p< 0,05). Após o desafio ácido, o grupo controle manteve os maiores valores (0,044 ± 0,014 Lp) com diferença significante para os demais grupos (p< 0,05), exceto para o Desensibilize Nano P (0,037 ± 0,019 Lp). Quanto à citotoxicidade, não houve diferença entre os grupos experimentais (p> 0,05). Assim, foi possível concluir que o uso de dessensibilizantes à base de biovidros causou efeito similar ao uso de produtos disponíveis comercialmente, em relação à permeabilidade e propriedades biológicas da dentina(AU)

The aim of this study was to evaluate the obliterating capability of different desensitizing agents on human dentin by measuring dentin permeability, and their biological performance by the analysis of cytotoxicity in human gingival fibroblasts. Fifty human molars were used, from which dentin blocks were obtained (4x4x1mm) and distributed in groups according to the desensitizing agent used (n=10): Group 1 - Control (Artificial saliva. No desensitizing agent applied); Group 2 ­ Ultra EZ (Ultradent); Group 3 ­ Desensibilize Nano P (FGM); Group 4 - T5-OH Bioactive Glass (Experimental solution); Group 5 - F18 Bioactive Glass (Experimental solution). The desensitizing treatments were performed for 15 days. In addition, the specimens were subjected to challenge with citric acid to simulate oral environment demineralizing conditions. Samples were subjected to permeability analysis before and after the desensitizing procedures and the acid challenge. Cytotoxicity analysis was performed by using Alamar Blue assay and complemented by total protein quantification by Pierce Bicinchoninic Acid (BCA) assay (N=3; n=3) at 15 minutes, 24-hour and 48-hour time points. Scanning electron microscopy (SEM) and energy dispersion X-ray spectroscopy (EDS) were performed for qualitative analysis of treated dentin. Data of dentin permeability was analyzed by twoway repeated measures ANOVA and Tukey's post-hoc test (α=0.05). For cytotoxicity, Kruskal-Wallis and Newman-Keuls tests were used (α=0.05). The results showed that for dentin permeability there was no significant difference among the desensitizing agents after treatment (p> 0.05), but the control group presented the highest values (0.131 ± 0.076 Lp, p< 0.05). And after acid challenge, the control group maintained the highest values (0.044 ± 0.014 Lp) with significant difference to the other groups (p< 0.05), except for Desensibilize Nano P (0.037 ± 0.019 Lp). For cytotoxicity, there were no significant differences among the experimental groups (p> 0.05). It was concluded that the use of bioglass-based desensitizers caused similar effects to commercially available products, regarding permeability and dentin biological properties(AU)

In vitro dentin permeability and tubule occlusion of in-office desensitizing materials / Permeabilidade da dentina e oclusão tubular in vitro de materiais dessensibilizantes de consultório

Objetivo: O objetivo desse estudo foi investigar a permeabilidade dentinária e a oclusão tubular de materiais dessensibilizantes de uso em consultório. Métodos: Blocos de dentina bovina foram obtidos e imersos em EDTA 0,5 M para promover a abertura dos túbulos dentinários. Os materiais testados foram: verniz placebo (PLA); verniz fluoretado (FLU); verniz de NaF 5% + 5% trimetafosfato de sódio nanoparticulado (TMP); sistema adesivo universal (SBU); verniz contendo partículas S-PRG (SPRG); solução de Biosilicato (BIOS) e solução de amelotina (AMTN). Os materiais foram aplicados e os espécimes submetidos ao desafio erosivo-abrasivo. A permeabilidade dentinária foi avaliada em T0 (inicial), T1 (após a aplicação dos materiais) e T2 (após o desafio erosivo-abrasivo). As imagens confocais foram usadas para avaliar o comprimento e o número dos túbulos ocluídos e as imagens de microscopia eletrônica de varredura (MEV) para avaliar o número de tubulos abertos. Os dados de permeabilidade e MEV foram analisadas pelo teste ANOVA duas medidas repetidas e pós teste de Tukey. O comprimento e número de túbulos dentinários ocluídos foram analisadas pelo teste ANOVA um critério e pós teste de Tukey, Kruskal-Wallis e pós teste de Dunn's, respectivamente. Os testes de correlação de Spearman e Pearson também foram realizados. O nível de significância foi de 5%. Resultados: O grupo AMTN mostrou os menores valores de permeabilidade em T1 e a seguinte ordem decrescente ocorreu em T2: AMTN=SBU>BIOS=SPRG>TMP>FLU>PLA. O grupo SBU teve o maior comprimento médio de túbulos dentinários ocluídos. O grupo AMTN teve maior número de túbulos dentinários ocluídos do que PLA e FLU e os menores valores de túbulos dentinários abertos foram observados para os grupos AMTN e SBU. Uma correlação significativa foi encontrada entre as análises realizadas. Significância: O sistema adesivo universal e a proteína amelotina foram mais efetivos em reduzir a permeabilidade dentinária através da oclusão dos túbulos dentinários(AU)

Objectives: The aim of this study was to investigate the dentin permeability and tubule occlusion of in-office desensitizing materials. Methods: Bovine dentin blocks were obtained and immersed in 0.5 M EDTA to open dentinal tubules. The materials tested were: placebo varnish (PLA); fluoride varnish (FLU); NaF 5% + 5% nanoparticulate sodium trimetaphosphate varnish (TMP); universal adhesive system (SBU); S-PRG filler-containing varnish (SPRG); Biosilicate solution (BIOS) and amelotin solution (AMTN). The materials were applied, and specimens were submitted to an erosive-abrasive challenge. Dentin permeability was evaluated at T0 (initial), T1 (after application of materials) and T2 (after erosive-abrasive challenge). Confocal images were used to evaluate length and number of dentinal tubules occluded and images from scanning electron microscopy (SEM) to evaluate opened dentinal tubules. Permeability and SEM data were evaluated by two-way repeated measures ANOVA and Tukey tests. The length and number of dentinal tubules occluded were evaluated by one-way ANOVA and Tukey, Kruskal-Wallis and Dunn's tests, respectively. Spearman and Pearson correlation tests were also used. The significance level was 5%. Results: AMTN group showed the lowest permeability value in T1 and the following decreasing order occurred in T2: AMTN=SBU>BIOS=SPRG>TMP>FLU>PLA. SBU group had the highest mean value of dentinal tubules occluded lengths. AMTN group had greater number of dentinal tubules occluded than PLA and FLU and the lowest values of opened dentin tubules were observed for AMTN and SBU groups. A significant negative correlation was found between the analysis. Significance: Universal adhesive system and the AMTN solution were more effective to reduce dentin permeability by occluding dentin tubules(AU)

Efeitos de diferentes dentifrícios na permeabilidade e rugosidade de dentina erodida / Effect of different toothpastes on permeability and roughness of eroded dentin

O objetivo deste estudo foi avaliar a rugosidade, a obliteração dos túbulos dentinários e a permeabilidade da dentina erodida e escovada com diferentes dentifrícios. Noventa dentes bovinos foram seccionadas em blocos, sendo que em trinta a hemiface foi protegida com verniz ácido resistente e sessenta foram submetidos ao teste de permeabilidade. Os espécimes foram divididos de acordo com os dentifrícios: sem flúor (SF), com fluoreto de sódio (NaF) e com fluoreto de estanho (SnF2). Em seguida, os blocos foram submetidos a um protocolo erosivo-abrasivo por 5 dias. As análises de rugosidade superficial e obliteração dos túbulos dentinários (n=10) foram realizadas nas hemifaces controle e teste do mesmo espécime e a análise da permeabilidade (n=20) foi realizada novamente. Os dados foram submetidos aos testes de ANOVA a dois critérios medidas repetidas e pós teste de Tukey (p≤0,05). Os grupos NaF e SnF2 apresentaram maior rugosidade comparando-se ao SF. O grupo SF apresentou a maior quantidade de túbulos abertos quanto comparado aos demais. Não houve diferença significativa na permeabilidade pós-ciclagem entre os dentifrícios SF e NaF, contudo o dentifrício SnF2 apresentou maior permeabilidade comparando-se aos demais. Ambos os dentifrícios contendo flúor tiveram oclusão efetiva dos túbulos dentinários; contudo, os efeitos da presença de fluoreto de estanho na permeabilidade podem ser neutralizados pela abrasão deste dentifrício(AU)

The aim of this study was to evaluate the roughness, dentin tubule occlusion and permeability of eroded dentin brushed with different toothpastes. Ninety bovine teeth were sectioned in blocks. The hemiface of thirty specimens was protect with acid resistant varnish and sixty were submitted to permeability test. The specimens were divided according to the dentifrices: without fluoride (WF), sodium fluoride (NaF) and stannous fluoride (SnF2). Then, the blocks were submitted to erosive-abrasive protocol for 5 days. The analysis of surface roughness and dentin tubule occlusion (n=10) were performed on control and test hemifaces of the same sample and permeability analysis (n=20) was again performed. Data were analyzed by two-way RM ANOVA and Tukey tests (p≤0.05). NaF and SnF2 groups presented higher roughness when compared with WF. WF group presented larger number of opened tubules compared to the others. No significant differences were found between WF and NaF for permeability; however, SnF2 presented higher hydraulic conductance compared to other dentifrices. In conclusion, both fluoride-containing toothpastes had promising tubule occlusion; however, the effects on permeability of stannous formulation may be counteracted by the effects of abrasion from this dentifrice(AU)

Efecto del EDTAC y del ácido cítrico sobre la pared dentinaria. Variación del tiempo de exposición y la edad dentaria / Effect of EDTAC and citric acid on dentinal walls. Variation of exposure time and dental age

The aim of this study was to find a formula and application time for chelators effective in cleaning the root canal without causing erosion and considering dental age. The sample included 120 teeth: 60 taken from young patients and 60 from adult patients. They were instrumented and irrigated with 2.5% sodium hypochlorite (NaOCl). Each subgroup was divided randomly into six groups: 4 groups of 12 teeth and 2 control groups of 6 teeth. In the final irrigation, 17% ethylenediaminetetraacetic acid plus Cetavlón (EDTAC) or 10% citric acid was applied for 1 or 3 minutes according to each group. The results showed a high level of cleanliness, and a few showed erosion of the dentinal tubules. Satisfactory results were obtained in the removal of the smear layer when applying EDTAC or citric acid combined with NaOCl. Erosion was present in different degrees regardless of dental age, but it was indeed affected by the irrigant exposure time.

O objetivo deste estudo foi obter uma fórmula e um tempo de aplicação dos quelantes efetivos que permitam a limpeza das paredes do canal sem causar erosões, levando em consideração a idade dental. A amostra foi composta por 120 dentes, 60 de pacientes jovens e 60 de pacientes adultos, foram instrumentados e irrigados com hipoclorito de sódio (NaOCl) a 2,5%. Cada subgrupo foi dividido aleatoriamente em 6 grupos: 4 grupos de 12 dentes e 2 grupos de controle com 6 dentes cada um. Na irrigação final, ácido etilenodiaminotetracético com Cetavlón (EDTAC) 17% ou ácido cítrico 10% foi aplicado por 1 ou 3 minutos, dependendo do grupo. Os resultados mostraram um bom nível de limpeza com algumas amostras com erosão dos túbulos dentinários. Com EDTAC ou ácido cítrico combinado com NaOCl, resultados satisfatórios foram obtidos na remoção da camada de esfregaço . A erosão esteve presente em seus diferentes graus independentemente da idade dentária, mas não do tempo de exposição do irrigante.

Efecto de la aplicación activa con aplicadores mejorados de un adhesivo universal / Effect of the active application of a universal adhesive with improved applicators

RESUMEN Introducción: La permeabilidad dentinaria es conocida como el paso de fluidos, iones, partículas, moléculas y bacterias a través de la dentina bajo ciertas condiciones. Objetivo: Determinar la influencia de la aplicación activa con un aplicador mejorado de un adhesivo dentinario sobre la conductancia hidráulica dentinaria humana, in vitro. Métodos: Estudio experimental in vitro en 40 terceros molares libres de caries, con indicación de exodoncia, provenientes de pacientes sanos entre 15 y 30 años, previo consentimiento informado. Posteriormente se limpiaron, desinfectaron y conservaron para ser incluidos en bloques de resina epóxica. Luego se realizaron cortes transversales y se obtuvieron discos dentinarios de 1,5 mm de espesor y 25 mm de diámetro. Se dividieron en dos grupos de 20 unidades cada uno, se sometieron a grabado con ácido ortofosfórico al 37 por ciento, y se lavaron y secaron. Sobre una balanza de precisión se les aplicó adhesivo dentinario fotopolimerizable, registrando la fuerza ejercida. En el grupo 1 se usó un microbrush en la aplicación y en el grupo 2 un aplicador mejorado diseñado especialmente. Posteriormente cada muestra fue sometida a una cámara de difusión para obtener la tasa de flujo y luego calcular la conductancia hidráulica, la cual otorga información acerca de la permeabilidad de la dentina. Resultados: los resultados obtenidos fueron levemente menores en el grupo 2, sin embargo, experimentaron una distribución normal. Conclusiones: no existen diferencias significativas, al ser analizados estadísticamente bajo diversas pruebas, en los valores de conductancia hidráulica. Tampoco se pudo establecer una relación inversa entre la fuerza de aplicación de un adhesivo en forma activa con un aplicador mejorado y la conductancia hidráulica, por lo cual no se aconseja el uso de dicho instrumento(AU)

ABSTRACT Introduction: Dentin permeability is defined as the passage of fluids, ions, particles, molecules and bacteria through the dentin under certain conditions. Objective: Determine the effect of the active application of a dentin adhesive with an improved applicator on human dentin hydraulic conductance in vitro. Methods: An in vitro experimental study was conducted of 40 caries-free third molars with an indication of exodontia from healthy patients aged 15-30 years, prior informed consent. The molars were cleaned, disinfected and preserved to be included in epoxy resin blocks. Cross-sectional cuts were then made to obtain dentin discs 1.5 mm thick and 25 mm in diameter. These were divided into two 20-unit groups, were subjected to etching with 37 percent orthophosphoric acid, and were washed and dried. On a precision scale photopolymerizable dentin adhesive was applied, recording the force exerted. Application was performed with a Microbrush applicator in Group 1 and with an improved dedicated applicator in Group 2. The samples were then placed in a diffusion chamber to determine flow rate and subsequently estimate hydraulic conductance, thus obtaining information about dentin permeability. Results: Results were slightly lower in Group 2, but they displayed normal distribution. Conclusions: Statistical analysis with various tests did not find any significant differences in hydraulic conductance values, nor could an inverse relation be established between the force of active application of an adhesive with an improved applicator and hydraulic conductance. Therefore, use of that instrument is not advised(AU)

Diferentes Protocolos de Grabado Ácido en Dentina; Estudio Micromorfológico / Different protocols for acid etching in dentin; micromorphological study

RESUMEN: El objetivo fue evaluar las características de túbulos dentinarios expuestos por acción de diferentes protocolos de grabado en distintas zonas dentinarias. Se midió densidad tubular y diámetro. Se estudiaron 60 primeros premolares humanos sanos sometidos a tratamiento de endodoncia. Se realizaron cortes de las raíces a 5mm del límite amelocementario y en sentido longitudinal bucolingual, obteniendo mitades iguales (mesial y distal) que se agruparon según tratamiento acondicionador a recibir: Control, EDTA, H3PO4 15 y 45 seg., y H3PO4 15 y 45 seg. + NaOCl. Se realizó análisis en MEB en tres sectores: dentina coronaria, cámara pulpar e inicio del conducto radicular. La comparación entre las secciones se analizó mediante prueba t de Student para datos apareados, fijando valor p<0,05 para significación estadística. Se utilizó programa Infostat versión profesional 2009. No se observaron diferencias significativas en los grupos al comparar densidad tubular para las tres zonas estudiadas. Al comparar diámetro de los túbulos, se obtuvieron valores mayores cuando se acondicionó con ácido ortofosfórico al 45% + NaOCl. Los resultados ponen de manifiesto el comportamiento clínico heterogéneo de las distintas zonas dentinarias luego de diferentes protocolos para adhesión con técnica de grabado total. Protocolo tradicional de acondicionamiento con ácido ortofosfórico al 35% por 15 segundos no asegura grabado uniforme de las tres zonas dentinarias estudiadas. Protocolos donde se aumenta el tiempo de grabado y/o se incorpora NaOCl al 5% por un minuto como agente desproteinizante podrían permitir patrones más predecibles y apropiados de grabado en las tres zonas estudiadas de dientes endodonciados.

ABSTRACT: Evaluate in endodontically treated teeth the effects of different etching protocols on dentinal tubule exposure and diameter at three dentin zones. Sixty healthy first premolars from human volunteers were studied. Each tooth received endodontic treatment. Teeth were transversely sectioned 5 mm below amelocemental junction and longitudinaly sectioned in the buccolingual direction, obtaining two crown halves. Each crown half was grouped according to etching protocol into: Control, EDTA, H3PO4 15 and 45 sec., y H3PO4 15 and 45 seg. + NaOCl. Three dentinal areas were analyzed with scanning electron microscope (SEM) within each tooth: coronal dentin, pulp chamber dentin and the beginning of the root canal. Comparison between dentin zones for each treatment was made with Student's t-test for paired data, using P<0.05 for statistical significance. No significant differences in dentinal tubule exposure within the three studied zones were found. However, when comparing tubule diameter, higher values were obtained at the three dentin zones studied when H3PO4 and NaOCl wer used in combination. The results of this study showed heterogeneous behavior of different dentin zones after exposing them to various total etch protocols. The use of 37% H3PO4 for 15s did not ensure a uniform etch in the three studied zones. Protocols with H3PO4 for 45s with 5%NaOCl for 1 min, incorporated as a deproteinizing agent, could allow more predictable and appropriate etching patterns in endodontically treated teeth.

Effect of Erosion/Abrasion Challenge on the Dentin Tubule Occlusion Using Different Desensitizing Agents

The aim of the study was to evaluate dentinal tubule occlusion, measuring the dentin permeability (Lp) and using different desensitizing agents before and after abrasive/erosive challenge. Dentin discs from 42 healthy human third molars were obtained. Minimum Lp was measured after a smear layer simulation using #600 SiC paper and maximum Lp after an immersion in 0.5 M EDTA. The specimens were treated with different desensitizers: two varnishes (Clinpro XT Varnish-CV, Fluor Protector-FP), a paste (Desensibilize Nano P-NP) and a gel (Oxa Gel-OG). The Lp of each specimen was measured immediately after the desensitizers’ application. The discs were subjected to erosion/abrasion cycles for 7 days, with 0.5% citric acid solution (6x/day) and tooth brushing (3x/day). Lp was measured after the first, fourth and seventh day of the challenge. The data were analyzed by 3-way ANOVA with repeated measurements and by a Games-Howell test (α=5%). FP and CV did not show significant differences in Lp immediately after application until the 7th day (p<0.05). OG showed a significant increase in Lp after the 4th and 7th days. NP resulted in a significantly higher permeability compared to the other materials immediately after the application and after the 1st day of challenge. All the desensitizers reduced the dentin permeability immediately after application. However, only the varnishes were able to maintain the occlusive effect after the erosion/abrasion challenge.

Resumo O objetivo do estudo foi avaliar a permeabilidade da dentina (Lp) usando diferentes agentes dessensibilizantes antes e depois de um desafio abrasivo/erosivo. Discos de dentina foram obtidos a partir 42 terceiros molares humanos. Lp mínima foi medida após uma simulação de smear layer usando lixa de SiC # 600 e a Lp máxima foi medida após imersão em EDTA 0,5 M. As amostras foram tratadas com diferentes dessensibilizantes: dois vernizes (Fluor Protector-FP, Clinpro XT Varnish-CV), uma pasta (Desensibilize Nano P-NP) e um gel (Oxa Gel-OG). A Lp de cada amostra foi medida imediatamente após a aplicação dos dessensibilizantes. Os discos foram submetidos a um ciclo de erosão/abrasão durante 7 dias, com uma solução de 0,5% de ácido cítrico (6x/dia) e escovação (3x/dia). Lp foi medida do primeiro ao sétimo dia do desafio. Os dados foram analisados por ANOVA a 3 critérios com medidas repetidas e teste de Games-Howell (α=5%). FP e CV demonstraram Lp semelhante imediatamente depois da aplicação até 7 dias (p<0,05). OG apresentou um aumento significativo na Lp depois do 4º e 7º dias. NP resultou numa permeabilidade significativamente mais elevada comparada com a dos outros materiais imediatamente após a aplicação e após o primeiro dia de desafio. Todos os dessensibilizantes reduziram a permeabilidade da dentina imediatamente após a aplicação. No entanto, apenas os vernizes foram capazes de manter o efeito oclusivo após o desafio da erosão/abrasão.

Effect of two desensitizing agents on dentin permeability in vitro

Abstract Objective The aim of this in vitro study was to investigate the effect of two desensitizing agents and water on hydraulic conductance in human dentin. Material and Methods GLUMA Desensitizer PowerGel (GLU) contains glutaraldehyde (GA) and 2-hydroxyethyl methacrylate (HEMA), and Teethmate Desensitizer (TD) is a powder comprising tetracalcium phosphate (TTCP) and dicalcium phosphate anhydrous (DCPA) that is mixed with water. Deionized water was used as a negative control (CTR). Thirty discs with a thickness of 1.2 mm were cut from the coronal dentin of the third molars and cleaned with 0.5 M EDTA (pH 7.4). After being mounted in a split-chamber device, the discs were pressurized with water at 1 kPa and 3 kPa in order to measure flow rates with a highly sensitive micro-flow sensor and to calculate hydraulic conductance as a baseline value (BL). Following the application of GLU, TD, and CTR (n=10), hydraulic conductance was remeasured with intermittent storage in water after 15 min, 1 d, 1 w, and 1 m. Reduction in permeability (PR%) was calculated from hydraulic conductance. Data were statistically analyzed using nonparametric methods (α<0.05). Representative discs were inspected by SEM. Results PR% for GLU and TD were 30-50% 15 min and 1 m after their application. Post hoc tests indicated that PR% of CTR was significantly greater than those of GLU and TD at all time points tested. The PR% of GLU and TD were not significantly different. SEM examinations showed noncollapsed collagen meshes at the tubular entrances after GLU, and crystalline precipitates occluding the tubular orifices after TD, whereas CTR specimens showed typical patterns of etched dentin. Conclusions The present study on hydraulic conductance in dentin discs treated with two chemically different desensitizing agents and water as a control demonstrated that both products may be characterized as effective.

Avaliação da obliteração de túbulos dentinários, concentração mineral e permeabilidade dentinária após o uso de dentifrícios contendo trimetafosfato de sódio microparticulado e nanoparticulado: estudo in vitro / Evaluation of obliteration of the dentinal tubules, mineral concentration and dentin permeability after the use of toothpastes containing microparticle and nanoparticle sodium trimetaphosphate: in vitro study

O objetivo deste trabalho foi avaliar in vitro a ação do trimetafosfato de sódio microparticulado (TMPm) ou nanoparticulado (TMPn) associado ao fluoreto (F) em formulações de dentifrícios na obliteração dos túbulos dentinários (TD), concentração mineral e condutância hidráulica. Blocos de dentina radicular bovina (4×4×2 mm) foram planificados e os TD desobliterados com solução de ácido fosfórico a 37%. Para o estudo da avaliação da obliteração dos túbulos e concentração mineral, os blocos (n=20/grupo) foram submetidos à escovação mecânica (2x/dia) durante 7 dias com dentifrícios: placebo, 1100 ppm F, 1100 ppm F associado a 3% TMPm, 1100 ppm F associado a 3% TMPn. Ao final dos tratamentos, dez blocos por grupo foram imersos em ácido cítrico (pH 3,2), durante 1 minuto. O número, diâmetro e área de TD desobstruídos foram quantificados utilizando microscopia eletrônica de varredura (MEV) e a % atômica dos elementos químicos (Ca, P, C, N e O) dos precipitados presentes nos TD foi determinada por energia dispersiva de raios-X. Foi avaliada a concentração mineral da dentina (gHAp × cm-3) utilizando um microtomógrafo com resolução espacial de 1,5 µm. Os dados foram submetidos à análise de variância (2-critérios) seguida pelo teste de StudentNewman-Keuls (p<0,05). Os dentifrícios contendo TMPm e TMPn produziram maior obliteração dos TD e maior concentração mineral quando comparados com outros grupos. Não foram observadas diferenças significativas entre 1100 TMPm e 1100 TMPn ou entre placebo e 1100 ppm F; porém o grupo 1100 ppm F apresentou maior concentração mineral quando comparado ao placebo. A proporção Ca/P foi maior nos grupos com TPM; o ataque ácido reduziu a proporção Ca/P para todos os grupos. A % de C e N foi significativamente menor para 1100 TMPm e 1100 TMPn antes do ataque ácido, mas aumentou depois. A % atômica de O foi maior antes do ataque ácido para grupos com TMP. Para o estudo da condutância hidráulica, determinou-se inicialmente a condutância máxima da dentina e os blocos (n=15/grupo) foram submetidos à escovação mecânica como descrito previamente. Após os tratamentos dos blocos, em 5 blocos de cada grupo foi analisada a superfície da dentina utilizando MEV. Nos demais blocos (n=10/grupo) foi determinada a condutância hidráulica pós-tratamento. Em seguida, os blocos foram imersos em ácido cítrico (pH 3,2) por 1 minuto e a condutância determinada novamente. Os dados foram submetidos à análise de variância (2-critérios) de medidas repetidas seguida pelo teste Student-Newman-Keuls (p<0,05). Todos os tratamentos apresentaram uma redução da condutância hidráulica. Uma redução significativa na condutância foi observada nos tratamentos com dentifrícios contendo TMP. Após o ataque ácido houve um aumento da condutância hidráulica em todos os grupos, exceto o grupo com TMPm. Os grupos com TMP produziram maior obliteração dos TD quando comparados aos outros grupos. Os dentifrícios contendo TMPm apresentaram precipitados com aglomerados maiores quando comparado ao TMPn. Concluiu-se que a adição de TMP microparticulado ou nanoparticulado a dentifrícios contendo 1100 ppm F levou a maior obliteração dos túbulos dentinários, maior concentração mineral e menor condutância hidráulica quando comparada ao 1100 ppm F(AU)

The objective of this study was to evaluate in vitro the effect of TMP microparticles (TMPm) or nanoparticles (TMPn) associated with fluoride (F) in toothpaste formulations on the obliteration of dentinal tubules (DT), mineral concentration and hydraulic conductance. Bovine root dentin blocks (4×4×2 mm) were ground flat and the DT were unobstructed by phosphoric acid 37%. For study of evaluation of the tubules obliteration and mineral concentration, the blocks (n=20/group) were submitted to mechanical brushing (2x/day) during 7 days with toothpastes: placebo, 1100 ppm F, 1100 ppm F associated with 3% TMPm, 1100 ppm F associated with 3% TMPn. After that, ten blocks of each group were immersed in citric acid (pH 3.2) for 1 minute. The number, diameter and area of unobstructed DT were quantified using scanning electron microscopy (SEM) and atomic % of chemical elements (Ca, P, C, N and O) from precipitates in DT were determined by energy-dispersive X-ray. Dentin mineral concentration (gHAp × cm-3) was evaluated utilizing Micro-CT at 1.5 µm of spatial resolution. Data were submitted to 2-way ANOVA, followed by Student-Newman-Keuls test (p<0.05). Toothpastes containing TMPm and TMPn promoted higher obliteration of DT and greater mineral concentration when compared to other groups. No significant differences were observed between 1100 TMPm and 1100 TMPn, or between placebo and 1100 ppm F; however 1100 ppm F group had higher mineral concentration compared to placebo. Higher Ca/P ratios were observed in the groups treated with TMP; the acid challenge reduced Ca/P ratio for all groups. The atomic % of C and N was significantly lower for 1100 TMPm and 1100 TMPn before acid challenge, but increased afterwards. The atomic % of O was higher before before acid challenge to TMP groups. For study of hydraulic conductance was determined initially the maximum hydraulic conductance of the dentin and the blocks (n=15/group) were subjected to mechanical brushing as described previously. After treatment of the blocks, in 5 blocks of each group was analyzed the dentin surface using SEM. In other blocks (n=10/group) was determined the post-treatment hydraulic conductance. After that, the blocks were submitted to citric acid (pH 3.2) by 1 minute, and the conductance determined again. The data was submitted to 2-way ANOVA repeated measures, followed by Student-Newman-Keuls test (p<0.05). All treatments showed a reduction in hydraulic conductance. A significant reduction in conductance was observed in the treatments with TMP toothpastes. After acid challenge, there was an increase of the hydraulic conductance in all groups, except TMPm group. The TMP groups produced higher obliteration of the DT when compared to the others. The toothpastes containing TMPm showed precipitates with bigger clusters when compared to TMPn. It was concluded that addition of TMP microparticles or nanoparticles to toothpastes containing 1100 ppm F led to greater obliteration of the dentinal tubules, higher concentration mineral and lower hydraulic conductance when compared to 1100 ppm F(AU)

Smear layer na endodontia, preservar ou remover? / Smear layer in endodontics, preserve or remove?

Introdução: todo canal radicular instrumentado, seja por métodos manuais ou rotatórios, apresentará a formação de uma lama de detritos sobre a parede dentinária, sendo esta composta tanto por matéria orgânica quanto inorgânica, denominada de smear layer. Em relação a sua remoção ou manutenção das paredes do canal, diversos autores apresentaram opiniões e resultados divergentes, gerando dúvidas aos clínicos em relação à conduta mais adequada a ser empregada no tratamento endodôntico. Objetivo: este trabalho, por meio de uma revisão de literatura, visa fornecer uma resposta clara, capaz de melhorar o prognóstico do tratamento. Metodologia: para isso, foram utilizados 25 trabalhos desde o ano de 1975 a 2014, coletados por meio das bases de dados PubMed e Web of Science, com as palavras chaves: "smear layer", "smear layer removal", "smear layer permeability", "smear layer bacteria" e "smear layer sealing". Conclusão: baseado na metodologia proposta pode-se concluir que a remoção da smear layer é a melhor conduta a ser tomada durante o tratamento endodôntico, pois proporciona uma ação antimicrobiana mais eficiente das substâncias irrigadoras e medicações intracanais, além de permitir um melhor selamento entre dentina e material obturador, reduzindo as chances de uma infiltração.

Introduction: the root canal instrumentation, either by manual or mechanicals methods, will result in a formation of debris layer on dentin surface composted by organic and inorganic tissues, denominated smear layer. Due to the several divergent opinion about its removal or maintenance into the root canal, the clinicians may have a doubt for the most appropriate conduct to be performed in endodontics treatments. Objective: this article aimed collect the mains results obtained by different authors to provide a clear answer capable of improving the treatment prognosis. Methods: for this, were used 25 articles since 1975 to 2014 collected by date base PubMed and Web of Science with the keywords "smear layer", "smear layer removal", "smear layer permeability", "smear layer bacteria" and "smear layer sealing". Conclusion: based in the informations obtained in this review, its was concluded that the smear layer removal can, not only, improve the antimicrobial action of the irrigants agents and intracanal medicaments, but also provide a most efficient sealing of the fillingmaterial to dentine wall, reducing the chances to occur a leak in its interface.

Avaliação in vivo e in vitro de diferentes protocolos no tratamento da hipersensibilidade dentinária cervical / In vivo and in vitro study of different protocols for the treatment of cervical dentin hypersensitivity

Este estudo possui duas partes distintas: 1. in vivo (randomizado e longitudinal) que teve como objetivo avaliar protocolos de tratamento para hipersensibilidade dentinária com laser de baixa potência (com diferentes dosagens), laser de alta potência e agente dessensibilizante, por um período de 12 e 18 meses; e 2. in vitro que teve como objetivo analisar a perda de estrutura de dois dentifrícios distintos (Colgate Total 12 e Colgate Pró Alívio) e analisar a permeabilidade dentinária dos tratamentos da etapa 01, associados aos dentifrícios, após diferentes ciclos de abrasão. Na parte in vivo, as lesões cervicais não cariosas de 32 voluntários, previamente submetidos aos critérios de elegibilidade ou exclusão, foram divididas em nove grupos (n=10): G1: Gluma Desensitizer (Heraeus Kulzer), G2: Laser de baixa potência com baixa dosagem (Photon Lase, DMC) (três pontos de irradiação vestibulares e um ponto apical: 30 mW, 10 J/cm2, 9 seg por ponto com o comprimento de onda de 810nm). Foram realizadas três sessões com um intervalo de 72 horas), G3: Laser de baixa potência com alta dosagem (um ponto cervical e um ponto apical: 100 mW, 90 J/cm2, 11 seg por ponto com o comprimento de onda de 810nm. Foram realizadas três sessões com um intervalo de 72 horas), G4: Laser de baixa potência com baixa dosagem + Gluma Desensitizer, G5: Laser de baixa potência com alta dosagem + Gluma Desensitizer, G6: Laser de Nd:YAG (Power LaserTM ST6, Lares Research®), em contato com a superfície dental: 1,0W, 10 Hz e 100 mJ, ? 85 J/cm2, com o comprimento de onda de 1064nm, G7: Laser de Nd:YAG + Gluma Desensitizer, G8: Laser de Nd:YAG + Laser de baixa potência com baixa dosagem, G9: Laser de Nd:YAG + Laser de baixa potência com alta dosagem...

O nível de sensibilidade de cada voluntário foi avaliado através da escala visual analógica de dor (VAS) com auxílio do ar da seringa tríplice e exploração com sonda após 12 e 18 meses do tratamento. Na parte 02, in vitro, foram utilizados terceiros molares humanos não irrompidos e recém-extraídos. Todos foram limpos e tiveram suas raízes separadas das coroas. As raízes foram seccionadas em quadrados de dentina com dimensões de 4x4x2 mm, os quais foram embutidos em resina Epoxi e devidamente polidos até uma curvatura de 0,3 ?m, analisados em perfilometria ótica. Estes foram imersos em solução de EDTA 17% por 2min para abertura dos túbulos e armazenados em uma solução de Soro Fetal Bovino diluído em salina tamponada com fosfato. Os espécimes foram divididos aleatoriamente em 12 grupos (n=10) G1: Sem tratamento de superfície, sem dentifrício; G2: Nd:YAG/sem dentifrício; G3: Gluma/sem dentifrício; G4: Nd:YAG + Gluma/sem dentifrício; G5: Sem tratamento de superfície/Colgate Total 12; G6: Nd:YAG/Colgate Total 12; G7: Gluma/Colgate Total 12; G8: Nd:YAG + Gluma/Colgate Total 12; G9: Sem tratamento de superfície/Colgate Pró Alívio; G10: Nd:YAG/Colgate Pró Alívio; G11: Gluma/Colgate Pró Alívio; G12: Nd:YAG + Gluma/Colgate Pró Alívio. Em seguida, as superfícies receberam a aplicação de fitas adesivas nas duas margens, mantendo uma área central de teste exposta de 4 x 1 mm, onde foram realizados os tratamentos de superfície e os ciclos de abrasão correspondentes a 1, 7, 30 e 90 dias de escovação (52 ciclos, 210 segundos de contato com o slurry; 361 ciclos, 1470 segundos de contato com o slurry; 1545 ciclos, 6300 segundos de contato com o slurry; 4635 ciclos, 18900 segundos de contato com o slurry, respectivamente). A cada etapa de abrasão, foi realizada análise em Perfilometria Ótica. Para as analises de permeabilidade e Microscopia Eletrônica de Varredura, foram utilizadas amostras circulares de 6 mm de diâmetro e 1 mm de espessura de dentina...

This study has two distinct parts: in vivo (randomized and longitudinal) that aimed to assess different protocols for the treatment of dentin hypersensitivity with low power laser (with different doses), high power laser and a desensitizing agent, for a period of 12 and 18 months; and an in vitro part that aimed to analyze the loss of structure of two toothpastes (Colgate Total 12 and Colgate Pro Relief) and analyze dentin permeability and micrographs after different abrasion cycles. In the in vivo part, the lesions from 32 patients, that were submitted to the inclusion and exclusion criterias, were divided into nine groups (n = 10): G1: Gluma Desensitizer (Heraeus Kulzer), G2: Low power laser with low dose (Photon Lase, DMC, three points of irradiation in vestibular portion and an apical point: 30 mW, 10 J/cm2, 9 sec per point with the wavelength of 810nm, with three sessions with an interval of 72 hours) G3: low power laser with high dose (one pointin the cervical area, and one apical point: 100 mW, 90 J/cm2, 11 sec per point with the wavelength of 810nm in three sessions with an interval of 72 hours), G4: Low power laser with low dose + Gluma Desensitizer, G5: Low power laser with high dose + Gluma Desensitizer, G6: Nd:YAG laser (Power LaserTM ST6, Research® in contact: 1.0W, 10 Hz and 100 mJ, ? 85 J/cm2, with the wavelength of 1064nm,), G7: Nd:YAG laser + Gluma Desensitizer, G8: Nd:YAG laser + low power laser with low dose G9: Nd:YAG laser + low power laser with high dose. The level of sensitivity of each volunteer was assessed by visual analogue scale of pain (VAS) with the aid of air from the triple syringe and exploration probe, 12 and 18 months after treatment. In the in vitro part, unerupted and recently extracted human third molars were used...

Effects of different desensitizing treatments on root dentin permeability

Abstract The objective of this study was to evaluate the effects of diode laser and a desensitizing dentifrice on dentin permeability. Fifty-two root dentin fragments were obtained (5 × 5mm) and treated with 24% EDTA gel. The samples were divided into 4 groups (n = 13): G1, control (no treatment); G2, diode laser (λ = 908 nm, 1.5 W, continuous mode, 20s); G3, application of abrasive dentifrice for 1 minute (Elmex Sensitive Professional (International Gaba); and G4, application of abrasive dentifrice for 1 minute followed by irradiation with diode laser. Ten samples per group were immersed in 2% methylene blue solution for 4h. The specimens were washed, longitudinally sectioned, observed under optical microscopy, photographed and assessed based on the degree of dye leakage. The remaining samples were observed under scanning electron microscopy (SEM). The leakage data were subjected to ANOVA test, followed by Tukey's t-test (α = 5%). Groups 2, 3 and 4 showed less dye penetration than the control group (p < 0.05), but were similar among each other. SEM images showed that dentinal tubules were open in G1, and fused and occluded in G2. Group 3 showed dentinal tubules that were occluded by the metal ions from the toothpaste. G4 presented similar characteristics to G3, and the presence of fused dentin. The diode laser and the dentifrice were effective in reducing dentinal permeability, and the combination of the two treatments did not show better results than either one used alone.

Dentin barrier cytotoxicity test with three-dimensional cell cultures / 北京大学学报(医学版)

Objective:To evaluate the cytotoxicity of four dentin filling materials and two dentin adhe-sives with a dentin barrier test and to compare the results with those in a conventional filter diffusion test in order to investigate the advantages of the dentin barrier test.Methods: Eugenol cement, zinc phos-phate cement, adhesive glass ionomer cement, composite resin and two self-etching adhesives ( REMI BOND and Adper Easy One) were tested.In the dentin barrier test, L929 mouse fibroblasts were three-dimensional cultured in polystyrene meshes.The dentin disks were cut from the human third molars, near the pulp and in parallel with the occlusal surface, and their permeability within the measurement area was evaluated by a hydraulic permeability device.A mesh with the cells was placed in the “pulp cavity” of the chamber and one dentin disk was put on the cell mesh and its “pulp side” was in contact with the mesh.The test materials and controls were in contact with the“occlusal side” of the dentine disks for 24 h.The cell viability was obtained with MTT assay and the results were expressed as a percentage of con-trol tissues.The Mann-Whitney U test was used to make the statistical analyses.In the filter diffusion test, after a 24 h contact between the test materials and the filters with monolayer cells, the filters were dyed and the grades of cytotoxicity were decided.Results:A mean permeability of the dentin disks near the pulp was 0.293 μL/(min· cm2· cmH2O)(1 cmH2O=0.098 kPa);In the dentin barrier test, Eu-genol cement, REMI BOND and Adper Easy One respectively reduced the cell survival rates to 82%, 63%and 54%.Other materials showed no or very low toxic reactions; In the filter diffusion test, the light-curing composite resin was moderately cytotoxic, the dental adhesive glass ionomer cement was mild-ly cytotoxic and the others were severely cytotoxic;All the six materials in the dentin barrier test had low-er cytotoxicity than in the filter diffusion test.Conclusion:The cytotoxicity of the test materials using the dentin barrier test with three-dimensional cell cultures is lower than that in the filter diffusion test, which has good correlation with the clinical situation.

Effect of adhesive system and application strategy on reduction of dentin permeability

This study evaluated the effect of adhesive systems and application strategies on dentin hydraulic conductance (HC). The buccal enamel was removed from bovine incisors to simulate laminate cavity preparations. After removing the roots and the coronal pulp, the buccal dentin was treated with EDTA solution (0.5 M) for 5 minutes, rinsed, ultrasonicated for 12 minutes and connected to a permeability device. HC of the specimens was measured at 10 psi (n = 5). Permeability was measured before and after bonding procedures using G-Bond (GB), Clearfil Tri-S Bond (CTS), Hybrid Coat (HY), Bond Force (BF), Adper Easy Bond (AEB) Silorane (SI), Clearfil SE Bond (CSE) and Adper Scotchbond Multi-Purpose (SMP) adhesives systems, which were applied following three strategies: 1) according to the manufacturers' instructions; 2) two coats of all-in-one self-etching adhesives (GB, CTS, HY, BF, AEB) or priming step plus two coats of bonding resin for the other systems (SI, CSE and SMP); and 3) a thin layer of a flowable composite applied over one coat of all-in-one self-etching adhesives or primed surface for SI, CSE and SMP adhesives. No significant difference was observed among the application modes concerning their ability to reduce HC. None of the adhesives showed complete sealing (100%) of the bovine tooth dentin. SI exhibited lower HC than SMP, however, they were not significantly different from the other systems. The results suggest that all systems tested result in an HC reduction of more than 90%. The wet bonding technique seemed to be more sensitive for dentin sealing.