Dentin bond strength evaluation between a conventional and universal adhesive using etch-and-rinse strategy

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

Molecular response of pulp fibroblasts after stimulation with pulp capping materials

Abstract This in vitro study evaluated cell viability and metabolism, nitric oxide release and production of two chemokines and one cytokine by cultured human dental pulp fibroblasts (HDPF) in contact with two glass ionomer cements (Ketac Molar-KM and Vitrebond-VB), Single Bond (SB) and calcium hydroxide (Dycal-DY). Cultures of HDPF were established by means of an explant technique. The specimens were prepared under sterile conditions and in disks measuring 5 mm x 2 mm obtained from a prefabricated mold and placed on a permeable membrane to avoid direct contact with the cells. Cytotoxicity was assessed by Trypan Blue exclusion method and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Nitric oxide release in cell supernatant was detected by the Griess Method whereas stromal derived factor-1 alpha (SDF-1α or CXCL12), chemokine (C-X-C motif) ligand 8 [Interleukin 8 (IL-8 or CXCL8)] and interleukin-6 (IL-6) were detected by ELISA. RT-qPCR was employed for gene expression analysis. Statistical analyses were performed by One-way ANOVA followed by Tukey's post hoc test for materials independent of the time, and Two-way ANOVA followed by Bonferroni correction test for the comparisons between materials and experimental time (p<0.05). Cytotoxic tests showed significant differences only for DY. Protein levels and mRNA expression were significantly increased for IL-8 for both periods of time. IL-6 production increased when fibroblasts were stimulated by KM. SDF-1α protein production and mRNA expression were not affected by any of the materials. There was a decrease in nitrate/nitrite levels only for KM. Although DY caused intense cell death and did not stimulate the production of the inflammatory mediators evaluated in this work, it is known that this event seems to be fundamental for the process of repair of the pulp tissue and formation of mineralized barrier. KM and VB increased production of proteins related to the inflammatory process, thus favoring tissue repair. Therefore, although these glass ionomer cements did not lead to large cell death, they should be used with caution.

Resumo Este estudo avalia in vitro a viabilidade e metabolismo celular, a liberação de óxido nítrico e a produção de duas quimiocinas e uma citocina por fibroblastos de polpa dentária humana em cultura (FPDH) em contato com dois cimentos de ionômero de vidro (Ketac Molar-KM e Vitrebond-VB), Single Bond (SB) e hidróxido de cálcio (Dycal-DY). As culturas de FPDH foram estabelecidas por meio de uma técnica de explante. As amostras foram preparadas em condições estéreis e em discos de 5 mm x 2 mm, obtidas de um molde pré-fabricado e colocadas em uma membrana permeável (Maxicell 24 W 0,4 µm) para evitar o contato direto com as células. A citotoxicidade foi avaliada pelo método de exclusão de Trypan Blue e pelo ensaio de MTT. A liberação de óxido nítrico no sobrenadante celular foi detectada pelo método Griess, enquanto fator 1 derivado do estroma (SDF-1α ou CXCL12), interleucina-8 (IL-8 ou CXCL8) and interleucina-6 (IL-6) foram detectados por ELISA. RT-qPCR foi empregada para análise de expressão gênica. As análises estatísticas foram realizadas por ANOVA a 1 critério, seguida pelo pós-teste de Tukey para os materiais independentes do tempo, e ANOVA a 2 critérios, seguida pelo teste de correção de Bonferroni para comparações entre materiais e tempo experimental (p<0,05). Os testes citotóxicos mostraram diferenças significativas apenas para DY. Os níveis da proteína e a expressão de RNAm para IL-8 aumentaram significativamente para ambos os tempos estudados. A produção de IL-6 aumentou quando os fibroblastos foram estimulados por KM. A produção da proteína e a expressão de RNAm para SDF-1α não foram afetadas por nenhum dos materiais. Houve uma diminuição nos níveis de nitrato/nitrito apenas para KM. Embora o DY tenha causado intensa morte celular e não tenha estimulado a produção dos mediadores inflamatórios avaliados neste trabalho, sabe-se que esse evento parece ser fundamental para o processo de reparo do tecido pulpar e formação de barreira mineralizada. Os cimentos de ionômero de vidro utilizados aumentaram a produção de proteínas relacionadas ao processo inflamatório, favorecendo a reparação tecidual e, portanto, esses materiais, embora não causem grande morte celular, devem ser utilizados com cautela.

Dental pulp fibroblasts response after stimulation with hema and adhesive system

Abstract This study evaluated in vitro cell viability and metabolism, nitric oxide release and production of chemokines by cultured human dental pulp fibroblasts (DPF) under contact with HEMA and Single Bond. Cultures of DPF were established by means of an explant technique. Once plated, cells were kept under contact with increasing concentrations of HEMA (10, 100 and 1000 nM) or Single Bond (SB) [10-fold serially diluted in culture medium (10-4, 10-3 and 10-2 v/v)] and also with polymerized SB components. Cytotoxicity was assessed by Trypan Blue exclusion method and MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay. Nitric oxide release on cell supernatant was detected by Griess Method whereas chemokines (CXCL12 and CXCL8) were detected by ELISA. RT-qPCR was employed for chemokines gene expression analysis. Cytotoxic tests showed significant differences for SB 10-2. None of the tested materials significantly altered NO levels. Protein levels of CXCL12 were significantly decreased only by HEMA. On the other hand, while CXCL12 mRNA remained unaltered, gene expression of CXCL8 had significant decrease with all materials, except for polymerized SB. In conclusion, Single Bond and HEMA at various concentrations, decreased expression and production of molecules involved in inflammatory processes and, therefore, the use of adhesive systems such as pulp capping materials must be viewed with caution due to its large cytotoxic effect when in close contact with the pulp.

Resumo Este estudo avaliou in vitro a viabilidade e metabolismo celular, liberação de óxido nítrico e produção de quimiocinas em cultura de fibroblastos de polpa dental humana (DPF) em contato com HEMA e Single Bond. Culturas de DPF foram estabelecidas por meio de uma técnica de explante. Uma vez plaqueadas, as células foram mantidas em contato com concentrações crescentes de HEMA (10, 100 e 1000 nM) ou Single Bond (SB) [10 vezes diluídas em série em meio de cultura (10-4, 10-3 e 10-2 v/v)] e também com SB polimerizado. A citotoxicidade foi avaliada pelo método de exclusão de Trypan Blue e pelo ensaio de 3-(4,5-dimetiltiazol-2-il)-2,5-difeniltetrazólio brometo (MTT). A liberação de óxido nítrico no sobrenadante celular foi detectada pelo método de Griess, enquanto as quimiocinas (CXCL12 e CXCL8) foram detectadas por ELISA. RT-qPCR foi empregada para análise de expressão gênica de quimiocinas. Testes citotóxicos mostraram diferenças significativas para SB 10-2. Nenhum dos materiais testados alterou significativamente os níveis de NO. Os níveis de proteína de CXCL12 foram significativamente diminuídos apenas pelo HEMA. Por outro lado, enquanto o RNAm de CXCL12 permaneceu inalterado, a expressão gênica de CXCL8 teve redução significativa com todos os materiais, com exceção do SB polimerizado. Em conclusão, Single Bond e HEMA, em várias concentrações, diminuíram a expressão e produção de moléculas envolvidas em processos inflamatórios e, portanto, o uso de sistemas adesivos, como o material protetor da polpa, deve ser visto com cautela devido ao seu grande efeito citotóxico quando em contato com a polpa.

Influence of Erosive and Abrasive Cycling on Bonding of Different Adhesive Systems to Enamel: An In situ Study

Abstract This study evaluated the impact of orange juice on the bond strength (BS) of dentin bonding systems (DBSs) to enamel surface after simulation with an in situ/ ex vivo erosive cycling. One hundred and ninety two bovine enamel fragments (4x4x2mm) were obtained and randomized regarding superficial microhardness and distributed to palatal devices for 8 volunteers, in three phases (one for each DBS), containing 8 blocks, which were, allocated in 4 pairs. Daily, these pairs were subjected extraorally to the following conditions: CONT- neither erosive nor abrasive challenge; ERO- erosive challenge only; ABR- abrasive challenge only and ERO + ABR- with erosive and abrasive challenges. Erosive cycles (immersion in orange juice, 3 times/day/5 min/5 days) or/and abrasive challenges (electric toothbrush, 3 times/day/1 min/5 days) were performed. After these cycles, all specimens were restored with the adhesive systems Adper Scotchbond Multi Purpose (MP), Adper Single Bond 2 (SB) or Clearfil SE Bond (SE), and the composite resin Filtek Z250. After 7 days, sticks (area ≅1 mm2) were obtained and subjected to the microtensile bond strength test (μTBS) at 0.5 mm/min. Data was statistically analyzed by ANOVA and Tukey tests (a=0.05). Failure modes were determined using a digital microscope (40´). DBS was the only statistical significant factor. SE was the unique DBS not affected in any challenge, whereas MP and SB performed according to the scenario. The adhesive and mixed failures were predominant in all groups. Overall performance suggested that BS to enamel after erosive /abrasive challenged by orange juice was not affected and it was material-dependent.

Resumo Este estudo avaliou o impacto de suco de laranja na resistência de união (RU) de sistemas adesivos dentinários (SAD) à superfície do esmalte após a simulação com uma ciclagem erosiva in situ/ex vivo. Cento e noventa e dois fragmentos de esmalte bovino (4x4x2mm) foram obtidos e randomizados considerando a microdureza superficial, e distribuídos em dispositivos palatinos para 8 voluntários, em três fases (uma para cada SAD), contendo 8 blocos, os quais foram alocados em 4 pares. Diariamente, esses pares eram submetidos às seguintes condições extraoralmente: CONT- sem desafio erosivo ou abrasivo; ERO- desafio erosivo somente; ABR- desafio abrasivo somente; e ERO+ABR- com desafio erosivo e abrasivo. A ciclagem erosiva (imersão em suco de laranja, 3 vezes/dia/5 min/5 dias) e/ou ciclagem abrasiva (escova dentária elétrica, 3 vezes/dia/1 min/5 dias) foram feitas. Após estas ciclagens, todos os espécimes foram restaurados com os sistemas adesivos Adper Scotchbond Multi Purpose (MP), Adper Single Bond 2 (SB) ou Clearfil SE Bond (SE), e com a resina composta Filtek Z250. Após 7 dias, palitos (área ≈1 mm) eram obtidos e submetidos ao teste de resistência de união por microtração (μTBS) a 0,5 mm/min. Os dados foram estatisticamente analisados por ANOVA e teste de Tukey (a=0,05). Os modos de fratura foram determinados utilizando um microscópio digital (40×). SAD foi o único fator estatisticamente significante. SE foi o único SAD não afetado por qualquer desafio, enquanto o MP e o SB apresentaram um desempenho de acordo com o cenário. As fraturas do tipo mista e adesiva foram predominantes em todos os grupos. O desempenho geral sugeriu que RU ao esmalte após desafio erosivo/abrasivo por suco de laranja não foi afetada e foi material-dependente.

Water interaction and bond strength to dentin of dye-labelled adhesive as a function of the addition of rhodamine B

ABSTRACT Objective This study investigated the effect of the fluorescent dye rhodamine B (RB) for interfacial micromorphology analysis of dental composite restorations on water sorption/solubility (WS/WSL) and microtensile bond strength to dentin (µTBS) of a 3-step total etch and a 2-step self-etch adhesive system. Material and Methods The adhesives Adper Scotchbond Multi-Purpose (MP) and Clearfil SE Bond (SE) were mixed with 0.1 mg/mL of RB. For the WS/WSL tests, cured resin disks (5.0 mm in diameter x 0.8 mm thick) were prepared and assigned into four groups (n=10): MP, MP-RB, SE, and SE-RB. For µTBS assessment, extracted human third molars (n=40) had the flat occlusal dentin prepared and assigned into the same experimental groups (n=10). After the bonding and restoration procedures, specimens were sectioned in rectangular beams, stored in water and tested after seven days or after 12 months. The failure mode of fractured specimens was qualitatively evaluated under optical microscope (x40). Data from WS/WSL and µTBS were assessed by one-way and three-way ANOVA, respectively, and Tukey’s test (α=5%). Results RB increased the WSL of MP and SE. On the other hand, WS of both MP and SE was not affected by the addition of RB. No significance in µTBS between MP and MP-RB for seven days or one year was observed, whereas for SE a decrease in the µTBS means occurred in both storage times. Conclusions RB should be incorporated into non-simplified DBSs with caution, as it can interfere with their physical-mechanical properties, leading to a possible misinterpretation of bonded interface.

Endocrown: a conservative approach / Endocrown: uma abordagem conservadora

The purpose of this clinical case description article was to present the planning sequence, indication, treatment and performance to obtain a crown of the Endocrown type. This clinical case description article illustrates a therapeutic option for functional and esthetic rehabilitation of a devitalized mandibular molar, presenting a small amount of remaining coronal tooth structure, by means of cementing a pure porcelain crown of the Endocrowntype (Adhesive Endodontic Crown). A 39-year-oldwoman presented to the Graduate clinic of the Bauru Dental School (FOB), University of São Paulo (USP),with the complaint that tooth #36 had an extensive and unsatisfactory composite resin restoration. The lithium disilicate-based system of monolithic porcelain was used with the lost wax technique. This therapy promoted the stability and retention of the indirect restoration, without the need for performing reconstruction of the above mentioned tooth, either by means of a cast metal core or reconstruction with intracanal post, there by reducing the treatment time. After the tooth preparation, the provisional restoration was done with acrylic resin to determine if the retention and stability of the remaining tooth was adequate to receive the indirect. The characteristics of the internal and external walls of the dental remnants, cervical termination, impression-taking, laboratory stages and adhesive cementation will be discussed. The major advantage of indicating an endocrown is the use of the dental remnants it self, particularly the pulp chamber, to promote retention and stability in cases without adequate height for performing complete dental and crown reconstruction...

O objetivo deste artigo de descrição de caso clínico foi apresentar a sequência de planejamento, indicação, tratamento e execução de uma coroa do tipo Endocrown (Coroa Endodôntica Adesiva).Este artigo ilustra uma opção terapêutica para reabilitação funcional e estética de um molar inferior desvitalizado, apresentando uma pequena quantidade de remanescente coronário, por meio da cimentação de uma coroa pura de porcelana do tipo Endocrown. Uma mulher de 39 anos de idade, apresentou-se à clínica de Pós-Graduação da Faculdade de Odontologia de Bauru (FOB) da Universidade de São Paulo(USP), com a queixa de uma extensa e insatisfatória restauração de resina composta no dente 36. O sistema monolítico de porcelana à base de dissilicato de lítio foi utilizado com a técnica da cera perdida.Esta técnica promoveu a estabilidade e a retenção da restauração indireta, sem a necessidade de realizara reconstrução do dente 36, quer por meio de um núcleo metálico fundido ou reconstrução com pino intra canal, reduzindo assim o tempo de tratamento.Após o preparo do dente, realizou-se a restauração provisória com resina acrílica e verificou-se se a retenção e estabilidade do remanescente dentário era adequada para receber a restauração do tipo Endocrown. As características das paredes internas e externas do preparo do remanescente dentário,término cervical, moldagem, etapas laboratoriais e de cimentação são discutidas. A principal vantagem da indicação de uma coroa do tipo Endocrown é a utilização do próprio remanescente dentário,particularmente a câmara pulpar, para promover a retenção e estabilidade em casos onde não haja altura adequada para a reconstrução coronária...

Effect of resin-modified glass-ionomer cement lining and composite layering technique on the adhesive interface of lateral wall

Interface integrity can be maintained by setting the composite in a layering technique and using liners. Objective The aim of this in vitro study was to verify the effect of resin-modified glass-ionomer cement (RMGIC) lining and composite layering technique on the bond strength of the dentin/resin adhesive interface of lateral walls of occlusal restorations. Material and Methods Occlusal cavities were prepared in 52 extracted sound human molars, randomly assigned into 4 groups: Group 2H (control) – no lining + two horizontal layers; Group 4O: no lining + four oblique layers; Group V-2H: RMGIC lining (Vitrebond) + two horizontal layers; and Group V-4O: RMGIC lining (Vitrebond) + four oblique layers. Resin composite (Filtek Z250, 3M ESPE) was placed after application of an adhesive system (Adper™ Single Bond 2, 3M ESPE) dyed with a fluorescent reagent (Rhodamine B) to allow confocal microscopy analysis. The teeth were stored in deionized water at 37oC for 24 hours before being sectioned into 0.8 mm slices. One slice of each tooth was randomly selected for Confocal Laser Scanning Microscopy (CLSM) analysis. The other slices were sectioned into 0.8 mm x 0.8 mm sticks to microtensile bond strength test (MPa). Data were analyzed by two-way ANOVA and Fisher's test. Results There was no statistical difference on bond strength among groups (p>0.05). CLSM analysis showed no significant statistical difference regarding the presence of gap at the interface dentin/resin among groups. Conclusions RMGIC lining and composite layering techniques showed no effect on the microtensile bond strength and gap formation at the adhesive interface of lateral walls of high C-factor occlusal restorations. .

Incipient caries lesions: from concept to actual treatment approaches

The concepts introduced by the Minimally Invasive Dentistry (MID) allowed the rising of new conservative treatment and assessment system for caries lesions' classification. In this context, the approaches of the incipient caries lesions surpass the use of only traditional restorative techniques. The aim of this study was to review the new caries classifications criteria (ICDAS and CAST), the importance of the early diagnosis of caries lesions and the clinical procedures for treatment in MID.

Influence of photocuring and storage time on the volumetric change of resin modified glass ionomer cements

AIM: This study evaluated the effect of photoativation and storage on the hygroscopic expansion of resin modified glass ionomers (Vitremer-3M/ESPE, Fuji II LC-GC Int., Vitro Fil LC-DFL). MATERIAL AND METHODS: The RMGIC were manipulated according to the manufacturer's instructions, inserted into a mold and kept in a darkness box for 15 minutes. Then, the samples were distributed into four groups (n=5): light-cured for 20s, light-cured for 40s, light-cured for 60s and not light-cured (control group). Each sample was storage in distilled water at 37ºC. The measurements of volumetric changes were made in three different times of storage: 24 hours, 7 days and 30 days. Volumetric changes were determined using Archimedes principle. Means and standard deviations values were analyzed by three-way analysis of variance and Tukey's test to compare significance between the groups (α=0,05). RESULTS: All materials underwent volumetric expansion after 30 days. Vitremer showed the less expansion when no light-cured. The time of light-cure did not influence the volumetric change, except for Fuji II LC, that showed great expansion when activated for 60s. Vitro Fil LC showed some degree of shrinkage after 7 days. CONCLUSION: This study concluded that photocuring can influence the volumetric change of resin modified glass ionomer cement.

Push-out bond strength and SEM evaluation of a new bonding approach into the root canal

OBJECTIVE: This study evaluated the performance of different adhesive systems in fiber post placement aiming to clarify the influence of different hydrophobic experimental blend adhesives, and of one commercially available adhesive on the frictional retention during a luting procedure. MATERIAL AND METHODS: One luting agent (70 Wt% BisGMA, 28.5% TEGDMA; 1.5% p-tolyldiethanolamine) to cement fiber posts into root canals was applied with 4 different adhesive combinations: Group 1: The etched roots were rinsed with water for 30 s to remove the phosphoric acid, then rinsed with 99.6% ethanol for 30 s, and blotdried. A trial adhesive (base to catalyst on a 1:1 ratio) was used with an experimental luting agent (35% Bis-GMA, 14.37% TeGDMA, 0.5% eDMAB, 0.13% CQ); Group 2: A trial adhesive (base to catalyst on a 1:2 ratio) was luted as in Group 1; Group 3: One-Step Plus (OSP, Bisco Inc.) following the ethanol bonding technique in combination with the luting agent as in Group 1; Group 4: OSP strictly following the manufacturer's instructions using the luting agent as in Group 1. The groups were challenged with push-out tests. Posted root slices were loaded until post segment extrusion in the apical-coronal direction. Failure modes were analyzed under scanning electron microscopy. RESULTS: Push-out strength was not significantly influenced by the luting agent (p>0.05). No statistically significant differences among the tested groups were found as Group 1 (exp 1 - ethanol-wet bonding technique)=Group 2 (exp 2 - ethanol-wet bonding technique)=Group 3 (OSP - ethanol-wet bonding technique)=Group 4 (control, OSP - water-wet bonding technique) (p>0.05). The dominating failure modes in all the groups were cohesive/adhesive failures, which were predominantly observed on the post/luting agent interface. CONCLUSIONS: The results of this study support the hypothesis that the proposal to replace water with ethanol to bond fiber posts to the root canal using highly hydrophobic resin is plausible, but this seems to be more the proof of a concept than a clinically applicable procedure.

Restabelecimento estético e funcional de incisivo central superior traumatizado por meio de clareamento dentário e cimentação de pino intracanal: controle de 2 anos / Esthetic and functional reestablishment of traumatized upper incisive using dental bleaching and glass-fiber post: two years control

Paciente do sexo feminino, 25 anos de idade, procurou tratamento estético queixando-se do escurecimento do dente 21. Foram realizados exames clínicos e readiográficos, comprovando a alteração de cor e o tratamento endodôntico satisfatório. O plano de tratamento foi proposto para estabelkecer a função e a estética do dente 21 (técnica mediata), associado ao clareamento externo, em consultório, dos dentes #15 a #25 e #35 a #45 co peróxido de hidrogênio a 35 por cento, ativado com luz híbrida, a fim de que fossem uniformizadas as tonalidades de cor dos dentes. Posteriormente, um pino de fibra de vidro foi fixado no canal radicular, com cimento de ionômero de vidro convencional, seguido pela restauração da abertura coronária com resina composta. As etapas do tratamento revelaram que o planejamento correto combinado com o conhecimento das técnicas disponíveis e das propriedades dos materiais são essenciais para a obtenção da excelência estética e funcional dos dentes em questão.

A 25-year-old woman was seeking for aesthetic treatment for her #21 tooth. Clinical and radiographic examinations were done confirming color change and satisfactory endodontic treatment. Thus, a treatment was proposed to reestablish function and aesthetics to the compromised teeth. The #21 tooth received internal bleaching and #15 to #25 and #35 to #45 teeth received external bleaching with a 35% hydrogen peroxide gel activated by hybrid light. This was performed in order to standardize the tonalities of the color of the teeth. Subsequently, a glass-fiber post was fixed inside the radicular conduct with conventional glass-ionomer cement and the endodontic coronal aperture was restored with composite resin. Treatment steps showed that the correct planning associated with the knowledge of available techniques and material properties are essential for reaching functional and aesthetic excellence.

Resolução estética em dente anterior: restauração de alteração hipoplásica, clareamento interno e pino intracanal / Aesthetic resolution in anterior teeth: hypoplasia restoration, intracoronal bleaching and root post

Um sorriso com forma, cor e proporções harmoniosas representa um papel importante na saúde psicológica do paciente e em seu convívio social. O presente artigo descreve a resolução de um caso clínico em que o dente 21 apresentava alteração hipoplásica na face vestibular e lesão de cárie, com comprometimento médio da estrutura remanescente, tratamento endodôntico satisfatório e discreto escurecimento do elemento dentário. Para solução estética e funcional do incisivo central superior esquerdo, foi proposta a associação de tratamentos, com remoção do tecido cariado e restauração com resina composta, clareamento dentário interno e cimentação de pino intracanal de fibra de vidro, alcançando satisfação pessoal do paciente e do profissional.

Cytotoxicity and biocompatibility of direct and indirect pulp capping materials

There are several studies about the cytotoxic effects of dental materials in contact with the pulp tissue, such as calcium hydroxide (CH), adhesive systems, resin composite and glass ionomer cements. The aim of this review article was to summarize and discuss the cytotoxicity and biocompatibility of materials used for protection of the dentin-pulp complex, some components of resin composites and adhesive systems when placed in direct or indirect contact with the pulp tissue. A large number of dental materials present cytotoxic effects when applied close or directly to the pulp, and the only material that seems to stimulate early pulp repair and dentin hard tissue barrier formation is CH.

In vitro interactions between lactic acid solution and art glass-ionomer cements

OBJECTIVES: Production of acids such as lactic acid contributes to establish a cariogenic environment that leads to dental substrate demineralization. Fluoride plays an important role in this case and, as fluoride-releasing materials, glass-ionomer cements are expected to contribute to minimize deleterious reactions. This study evaluated interactions of glass-ionomer cements used in atraumatic restorative treatment (ART-GICs) with an aqueous lactic acid solution, testing the null hypotheses that no changes occur in the pH of the solution or on the surface roughness and mass of the ART-GICs when exposed to lactic acid solution over a 6-week period. MATERIAL AND METHODS: Ketac Molar, Fuji IX, Vitro Molar and Magic Glass were tested, and compared to Filtek Z250 and Ketac Fil Plus as control groups. Six specimens of each material were made according to manufacturers' instructions. The pH of the solution and roughness and mass changes of each specimen were determined over 6 weeks. Each specimen was individually stored in 2 mL of 0.02 M lactic acid solution for 1 week, renewing the solution every week. pH of solution and mass of the specimens were monitored weekly, and surface roughness of the specimens was assessed before and at the end of the 6-week acid challenge. pH and mass data were analyzed statistically by repeated measures using one-way ANOVA and Tukey's post-hoc tests for each material. Paired t-tests were used for roughness analysis. Tukey's post-hoc tests were applied to verify differences of final roughness among the materials. Significance level was set at 5 percent. RESULTS: The null hypotheses were partially rejected. All materials were able to increase the pH of the lactic acid solution and presented rougher surfaces after immersion, while mass change was minimal and generally not statistically significant. CONCLUSIONS: These findings can be helpful to predict the performance of these materials under clinical conditions. A ...

Avaliação da rugosidade superficial em dentes restaurados com resina composta submetidos à clareação dentária / Evaluation of the surface roughnes in teeth restorated with composite resin submitted to dental bleaching

Este estudo verificou o efeito de 1 agente clareador caseiro e 1 agente clareador de consultório na rugosidade superficial de 2 marcas comerciais de resina composta. Foram realizadas 24 restaurações com as resinas compostas 4 Seasons (Ivoclar - Vivadent) e Opallis (FGM) em dentes bovinos que foram divididos aleatoriamente em 3 grupos de 8 dentes: grupo 1 - clareação com peróxido de carbamida a 10% (Over Night), 8 horas/dia; grupo 2 - clareação com peróxido de hidrogênio a 35% (Whiteness HP, FGM), 3 sessões de 45 minutos a cada 5 dias; grupo 3 - imersão em água destilada. O tratamento clareador foi realizado por 15 dias, em temperatura ambiente, e, logo em seguida, os espécimes foram imersos em água destilada, evitando-se a desidratação. Todos os grupos foram avaliados pelo teste de rugosidade (Ra) antes e após a clareação dentária. Somente os grupos 1 e 2 foram avaliados após 5 horas da clareação inicial, usando-se um rugosímetro. Os resultados foram analisados estatisticamente pela análise de variância (ANOVA) e pelo teste de Tukey (p < 0,05). Não houve diferença significante na rugosidade superficial para o grupo restaurado com a resina composta Opallis. O grupo restaurado com a resina composta 4 Seasons mostrou aumento da rugosidade após a clareação de consultório. O repolimento dos dentes restaurados com resina composta pode ser uma alternativa após a realização dos procedimentos de clareação dentária.

Controle do ecossistema bucal previamente ao tratamento restaurador definitivo / Oral environment control before restorative treatment

O presente trabalho teve o propósito de descrever através do relato de um caso clínico o tratamento da doença cárie visando à promoçãode saúde do paciente antes de intervenções restauradoras definitivas, visto que o tratamento deve ser realizado por meio de mudanças de hábitos dietéticos e higiênicos do paciente e não somente através de restauração das lesões com estabelecimento de um plano de tratamento individualizado para cada indivíduo. Procedeu-se aplicação de solução antimicrobiana à base de iodo, instrução de higiene oral e modificação dos hábitos alimentares. Foi realizado tratamento expectante no dente 15 e escavação em massa seguida da aplicação de cimento ionomérico nos demais dentes que apresentavam lesão cariosa. Realizou-se remineralização das manchas brancas, bem como foram seladas cicatrículas e fissuras dos dentes posteriores. Depois de restabelecida a saúde, foram substituídas as restaurações provisórias por definitivas. Mudanças na filosofia de tratamento da doença cárie, baseadas na alteração de hábitos do paciente e remoção de focos infecciosos têm sido apresentadas com o objetivo de promover uma mudança efetiva nesse paradigma, a fim de ampliar a longevidade dos dentes com menor intervenção operatória.

The aim of the present study was to describe caries disease treatment, by means of a clinical case report, with a view to promoting the patient's health before definitive restorative treatments, considering that treatment should include changes in the patient's dietary and hygiene habits, and not be restricted only to restoring lesions, as well as the establishment of an individualized treatment plan for each patient. Iodine-based antimicrobial solution was applied, instructions about oral hygiene and dietary habit changes were provided. The stepwise excavation technique was performed in tooth 15, mass excavation followed by the application of glass ionomer cement in the other teeth that presented carious lesions. White stain lesions were remineralized, and cicatrizes and fissures in the posterior teeth were sealed. After health was reestablished, the temporary restorations were replaced by definitive restorations. Changes in the treatment philosophy of caries disease, based on changes in the patient's habits and removal of foci of infection have been presented with the object of producing an effective change in this paradigm, in order to increase the longevity of teeth with less operative intervention.

Influência da ciclagem térmica na microinfiltração de restaurações com resina composta utilizando fucsina básica 0, 5 por cento / Thermocycling influence for assessing microleakage of restoration with resin composite using basic fuchsine 0, 5 por cento

Introdução : A microinfiltração na interface dente/restauração é considerada fator crítico nas restaurações com resina composta. Muitas são as técnicas para testar a propriedade de selamento marginal de restaurações "in vivo" e "in vitro" . O objetivo deste trabalho foi verificar a influência do número de ciclos no processo de termociclagem para o estudo da microinfiltração marginal de restaurações de resina composta. Materiais e Métodos : Foram confeccionadas, em pré-molares extraídos, 44 cavidades circulares localizadas em cemento e/ou dentina, na face vestibular e/ou lingual, e posteriormente restauradas com o sistema Single Bond / Z-100 (3M). As cavidades foram divididas em 4 grupos: Grupo 1- sem ciclagem térmica (controle), Grupo 2- 100 ciclos, Grupo 3- 200 ciclos, Grupo 4- 1000 ciclos. Após a termociclagem, tais grupos permaneceram armazenados por 24 horas a 37ºC, em fucsina básica a 0,5% . A seguir, cada dente foi incluído em um cilindro de resina poliestirênica e levado à máquina de corte de tecidos duros. Os cortes obtidos foram avaliados qualitativamente por dois examinadores calibrados, seguindo escores preestabelecidos de 0 a 4, de acordo com a penetração do corante. Resultados : Os resultados foram avaliados usando o teste não-paramétrico de Kruskal-Wallis e não mostraram diferença estatisticamente significante. Conclusão : Nas condições empregadas no presente trabalho, a termociclagem não promoveu diferenças estatisticamente significantes na microinfiltração de resinas compostas.

Introduction : Microleakage at interface tooth/restoration is considered critical factor at resin composite restoration. The aim of this study was to verify the influence of the number of cycles on thermocycling process for assessing the marginal microleakage of resin composite restorations. Materials and Methods : Forty four circular cavities were prepared in premolars with margins dentin. Each tooth received one cavity preparation at buccal and/or lingual surfaces and was restored with Single Bond/Z-100 system. The teeth were divided into four groups: Group 1 - no thermocycling (control group), Group 2 - 100 cycles, Group 3 - 200 cycles, Group 4 - 1000 cycles. After thermocycling, the teeth were stored and immersed in 0,5 % basic fuchsine solution at 37ºC for 24 hours. After this period, the specimens were totally embedded in polystyrene resin and sectioned by a hard tissue cut machine. The sections were evaluated by qualitative method following score pre-established from 0 to 4 according to stain penetration. Results : The results were analyzed by non-parametric Kruskal-Wallis' test and they showed no significant difference. Conclusion : Thermocycling, under the conditions of this study, did not influence statistically the microleakage of resin composite restoration when compared to control group.

Effect of surface treatments on the spreading velocity of simplified adhesive systems

OBJECTIVES: To determine the roughness of glass surfaces submitted to different treatments and to correlate it with the spreading velocity of two adhesive systems. MATERIALS AND METHODS: Glass slides were used as substrates to evaluate the spreading velocity of Single Bond and Prime & Bond NT adhesive systems. Six different surface treatments were compared: 1) no treatment; 2) silanization (SL); 3) sandblasting (SB); 4) SB + SL; 5) 10 percent hydrofluoric acid treatment (HF); 6) HF + SL. Before and after treatments, surface roughness was measured by a profilometer (Ra, æm). Drop volumes (10 æl) of the adhesive systems were deposited onto substrates with a micropipette to observe materials spreading during 30s. Data were expressed in mm/s as spreading velocity. Statistical significances among groups were analyzed using one-way and two-way-ANOVA designs and the SNK test. RESULTS: Significant differences in spreading velocity were found between materials (p < 0.001) and among treatments (p < 0.001). Silanization decreased the spreading velocity for both adhesives in comparison to groups where it was not performed (p < 0.05). Differences in roughness were found only for SB surfaces that were rougher than the others (p < 0.05). Silanization decreased the roughness of SB surfaces (p < 0.05). Linear regression did not indicate any correlation between spreading velocity and roughness (R = 0.173). CONCLUSION: Although surface treatments yielded different roughness, they did not provide differences in the spreading velocity of the simplified bonding systems studied. Silanization decreased bonding systems' spreading velocities.

OBJETIVO: Determinar a rugosidade de superficies submetidas a diferentes tratamentos e correlacionar rugosidade com velocidade de escoamento de sistemas adesivos MATERIAL AND MÉTODOS: Lâminas de vidro foram utilizadas como substrato para avaliar a velocidade de escoamento dos sistemas adesivos Single Bond and Prime & Bond NT. Seis diferentes tratamentos de superfície foram comparados: 1- sem tratamento; 2 - silanização (SL); 3 - jateamento (J); 4 - J + SL; 5 - condicionamento com ácido fluorídrico a 10 por cento (HF); 6 - HF + SL. Antes e após os tratamentos, foi mensurada a rugosidade das superficies (Ra, æm). Gotas de 10 æl de adesivo foram despositadas sobre as superficies e as velocidades de escoamento foram observadas durante 30 seg. Dados de velocidade de escoamento foram expressos em mm/s. Significâncias estatísticas entre grupos foram analisadas pelos testes ANOVA (um e dois critérios) e SNK. RESULTADOS: Houve diferenças significantes na velocidade de escoamento entre materiais (p < 0.001) e entre tratamentos (p < 0.001). Silanização diminuiu a velocidade de escoamento para ambos os adesivos em comparação aos grupos não silanizados (p < 0.05). Houve diferença entre rugosidades inicial e final somente para o grupo jateado, que se apresentou como o mais rugoso (p < 0.05). Silanização diminuiu a rugosidade das superficies jateadas (p < 0.05). Regressão linear não indicou correlação entre velocidade de escoamento e rugosidade (R = 0.173). CONCLUSÕES: Embora os tratamentos de superfície tenham produzido diferentes rugosidades, não produziram diferenças na velocidade de escoamento dos sistemas adesivos estudados. Silanização diminuiu a velocidade de escoamento dos sistemas adesivos.

Influência do instrumental nas características superficiais pós-acabamento e polimento de restaurações de resinas compostas / Instrumental influence on the superficial characteristics after finishing and polishing composite resin restorations

Acabamento e polimento de restaurações de resinas compostas, embora muitas vezes negligenciados, são responsáveis pela caracterização superficial e restituição anatômico-funcional do conjunto dente-restauração. No entanto, devido aos diversos materiais e instrumentos que podem ser empregados, as etapas de acabamento e polimento podem levar a diferentes características superficiais nas restaurações de resina composta e no dente, as quais são comparadas e exemplificadas, neste artigo, sob forma de fotomicrografias em microscópio eletrônico de varredura.