Caries-preventive efficacy and retention of a resin-modified glass ionomer cement and a resin-based fissure sealant: a 3-year split-mouth randomised clinical trial.

PURPOSE: This prospective clinical trial compared the retention rate and caries-preventive efficacy of two types of sealant modalities over a 3-year period. MATERIALS AND METHODS: Using a split-mouth randomised design, 1280 sealants were randomly applied on sound permanent second molars of 320 young patients aged between 12 and 16 years. Half of the teeth (n = 640) were sealed with a resin-modified glass ionomer cement (RMGIC) (Vitremer™, 3M ESPE) and the other half (n = 640) with a conventional light-cure, resin-based fissure sealant (LCRB) (Fluoroshield®, Dentsply Caulk). Teeth were evaluated at baseline, 6-, 12-, 18-, 24-, 30- and 36-month intervals with regard to retention and new caries development. RESULTS: On the sealed occlusal surfaces after 3 years, 5.10% of RMGIC and 91.08% of LCRB sealants were totally intact and 6.37% of RMGIC and 7.65% of LCRB sealants were partially intact. New caries lesions were found in 20.06% of RMGIC sealed occlusal surfaces, compared to 8.91% for LCRB sealants. CONCLUSIONS: The findings of the present clinical study suggest that RMGIC should be used only as a transitional sealant that can be applied to newly erupting teeth throughout the eruptive process, whereas LCRB sealants are used to successfully prevent occlusal caries lesions once an effective rubber dam can be achieved. It can be concluded that there are differences between the RMGIC and LCRB sealants over a 3-year period in terms of the retention rate and caries-preventive efficacy. RMGIC can serve as a simple and economic sealing solution, however provisional. Due to its poor retention rate, periodic recalls are necessary, even after 6 months, to eventually replace the lost sealant.

Oral hygiene indirect instruction and periodic reinforcements: effects on index plaque in schoolchildren.

The aim of this study was to evaluate the effectiveness of the indirect instruction and the influence of the periodic reinforcement on the plaque index in schoolchildren. Forty schoolchildren aged from 7 to 9 years old were selected from a public school. After determining the initial O'Leary Plaque Index all schoolchildren were submitted to a program for oral hygiene through indirect instruction -"The Smiling Robot". The schoolchildren were divided into 2 groups: with and without motivation reinforcement. The index plaque exam was performed in both groups after 30, 60 and 90 days of the educational program. Comparing the groups, the plaque index decreasing could be observed in the group with reinforcement with statistically significant difference. For the group with reinforcement, statistically significant difference among the evaluations was found. For the group without reinforcement, significant decrease in the plaque index was found after 30 days when compared to the first, third and fourth evaluations. The indirect instruction with "The Smiling Robot "promoted a positive initial impact on the decrease of plaque index in the schoolchildren. The periodic reinforcements showed more suitable results and significant reduction of the plaque index in the course of the evaluations.

Minimal alterations on the enamel surface by micro-abrasion: in vitro roughness and wear assessments.

OBJECTIVE: To evaluate the in vitro changes on the enamel surface after a micro-abrasion treatment promoted by different products. MATERIAL AND METHODS: Fifty (50) fragments of bovine enamel (15 mm × 5 mm) were randomly assigned to five groups (n=10) according to the product utilized: G1 (control)= silicone polisher (TDV), G2= 37% phosphoric acid (3M/ESPE) + pumice stone (SS White), G3= Micropol (DMC Equipment), G4= Opalustre (Ultradent) and G5= Whiteness RM (FGM Dental Products). Roughness and wear were the responsible variables used to analyze these surfaces in four stages: baseline, 60 s and 120 s after the micro-abrasion and after polishing, using a Hommel Tester T1000 device. After the tests, a normal distribution of data was verified, with repeated ANOVA analyses (p≤0.05) which were used to compare each product in different stages. One-way ANOVA and Tukey tests were applied for individual comparisons between the products in each stage (p≤0.05). RESULTS: Means and standard deviations of roughness and wear (µm) after all the promoted stages were: G1=7.26(1.81)/13.16(2.67), G2=2.02(0.62)/37.44(3.33), G3=1.81(0.91)/34.93(6.92), G4=1.92(0.29)/38.42(0.65) and G5=1.98(0.53)/33.45(2.66). At 60 seconds, all products tended to produce less surface roughness with a variable gradual decrease over time. After polishing, there were no statistically significant differences between the groups, except for G1. Independent of the product utilized, the enamel wear occurred after the micro-abrasion. CONCLUSIONS: In this in vitro study, enamel micro-abrasion presented itself as a conservative approach, regardless of the type of the paste compound utilized. These products promoted minor roughness alterations and minimal wear. The use of phosphoric acid and pumice stone showed similar results to commercial products for the micro-abrasion with regard to the surface roughness and wear.

Clinical strategies for esthetic excellence in anterior tooth restorations: understanding color and composite resin selection.

Direct composite resin restorations have become a viable alternative for patients that require anterior restorative procedures to be integrated to the other teeth that compose the smile, especially for presenting satisfactory esthetic results and minimum wear of the dental structure. Technological evolution along with a better understanding of the behavior of dental tissues to light incidence has allowed the development of new composite resins with better mechanical and optical properties, making possible a more artistic approach for anterior restorations. The combination of the increasing demand of patients for esthetics and the capacity to preserve the dental structure resulted in the development of different incremental techniques for restoring fractured anterior teeth in a natural way. In order to achieve esthetic excellence, dentists should understand and apply artistic and scientific principles when choosing color of restorative materials, as well as during the insertion of the composite resin. The discussion of these strategies will be divided into two papers. In this paper, the criteria for color and material selection to obtain a natural reproduction of the lost dental structures and an imperceptible restoration will be addressed.

Thermal-induced polymerization shrinkage in silorane versus methacrylate based resin composite / Contração de polimeração induzida termicamenteem resinas compostas a base de silorano e metacrilato

Shrinkage is a limitation of resin composite, compromising the clinical longevity of the restorative procedure. In an attempt to reduce their harmful effects, researchers have studied monomers with lower values of contraction. As a result, low-shrinkage composites were developed. This study evaluated quantitatively the shrinkage as a function of power density increase based on methacrylates, comparing them with silorane based resin, and qualitatively regarding gap formation between the adhesive interface as function of tooth substrate. Resin Filtek P90 and Filtek Z250 were polymerized with the device Blue Star 3 with 200, 400, 600, 800 and 1000 mW/cm2 keeping volume constant in 12 mm3. For qualitative analysis of restorative interface, class V cavity preparations in bovine incisors were restored in (2x2x2 mm3), photoactivated with the same values of irradiance, and analyzed by scanning electron microscopy at the interface of the wall surrounding enamel, dentin and axial. The quantitative results of the polymerization shrinkage were analyzed by two-way ANOVA and Tukey's test (p<0.05), while qualitative data were submitedd to Mann-Whitney's, Kruskal-Wallis' and Miller's tests. The progressive increase in power density directly influenced the polymerization shrinkage of the materials studied, although the silorane based resin demonstrated significantly lower values. The marginal integrity was influenced by the dental substrate and the power density used.

Este estudo avaliou quantitativamente a contração de polimerização em função do aumento dos valores de densidade de potência irradiados em compósitos à base de metacrilatos e silorano, e qualitativamente a interface restauradora em relação à abertura de fendas marginais, em função da variação do tipo de substrato dentário. As resinas Filtek Z250 e Filtek P90 foram fotoativadas com 200, 400, 600, 800 e 1000 mW/cm2, em um volume constante de 12mm3, e os valores de contração foram aferidos por meio da máquina de ensaios universal. Para análise qualitativa da interface restauradora, preparos cavitários classe V de (2x2x2mm3) foram restaurados em incisivos bovinos, fotoativados com os mesmos valores de irradiância, e analisados em microscopia eletrônica de varredura nas interfaces da parede circundante em esmalte, parede circundante em dentina e parede axial. Os resultados quantitativos da contração de polimerização foram analisados pelo teste ANOVA a dois critérios e Tukey (p<0,05) enquanto para os dados qualitativos os testes Mann- Whitney, Kruskal-Wallis e Miller foram empregados. O aumento progressivo da densidade de potência influenciou diretamente na contração de polimerização dos materiais estudados, não obstante a resina composta à base de silorano ter demonstrado valores significativamente menores. A integridade marginal sofreu influência do substrato dentário bem como da densidade de potência utilizada, para as duas resinas estudadas.

Effect of the polishing procedures on color stability and surface roughness of composite resins.

Objectives. To evaluate the polishing procedures effect on color stability and surface roughness of composite resins. Methods. Specimens were distributed into 6 groups: G1: Filtek Supreme XT + PoGo; G2: Filtek Supreme XT + Sof-Lex; G3: Filtek Supreme XT + no polishing; G4: Amelogen + PoGo; G5: Amelogen + Sof-Lex.; G6: Amelogen + no polishing. Initial color values were evaluated using the CIELab scale. After polishing, surface roughness was evaluated and the specimens were stored in coffee solution at 37°C for 7 days. The final color measurement and roughness were determined. Results. Sof-Lex resulted in lower staining. Amelogen showed the highest roughness values than Filtek Supreme on baseline and final evaluations regardless of the polishing technique. Filtek Supreme polished with PoGo showed the lowest roughness values. All groups presented discoloration after storage in coffee solution, regardless of the polishing technique. Conclusion. Multiple-step polishing technique provided lower degree of discoloration for both composite resins. The final surface texture is material and technique dependent.

Conservative approach for a clinical resolution of enamel white spot lesions.

Enamel white spot lesions in anterior teeth that compromise esthetics are common. Microabrasion is indicated, since it affects enamel superficially. An acid-abrasive slurry with 37% phosphoric acid with pumice was used on the enamel for a controlled time period. Home bleaching with hydrogen peroxide was then used, further improving the final result. The method is safe, easy, and conservative and provides good esthetic results.

Polishing techniques effect on microhybrid, nanohybrid and nanofilled composites color and surface roughness stability / Efeito de técnicas de polimento na estabilidade da cor e rugosidade superficial de resinas compostas microhibridas nanohibridas e nanoparticuladas

Resin roughness and staining is a common problem in dentistry. Objective: the aim of this study was to verify the influence of single and multiple-steps polishing techniques on color stability and surface roughness of differents composite resins. Groups were (n=10): FS+CS. Filtek Supreme XT + clear strip; FS+PG. Filtek Supreme XT+PoGo; FS+SF. Filtek Supreme XT+Sof-Lex; AM+CS. Amelogen+clear strip; AM+PG. Amelogen+PoGo; AM+SF. Amelogen+Sof-Lex; TEC+CL .TetricEvoCeram + clear strip; TEC+PG .Tetric EvoCeram+ PoGo; TEC+SF .Tetric EvoCeram+Sof-Lex; CED+CS .Ceram X Duo+clear strip; CED+PG. Ceram X Duo+PoGo; CED+SF. Ceram X Duo+Sof- Lex. The initial color and roughness were determined before and after the polishing procedures. All specimens were stored for 7 days in coffee solution and the color assessment was performed. Two specimens from each group were evaluated by scanning electron microscopy. Roughness and color data were submitted to ANOVA and Tukey tests(p<0.05). All tested materials presented color alterations after coffee solution storage; the highest E values were observed for clear strips and all composite resins, as following: G4 (9h)>G7(5.8f)=G10(5.7ef)>G1(3.7c), followed by the G6(5.9f)>G9(3.1bc)=G12(2.1ab)>G3(1.7a). G3, after 7 days, presented the lowest values for E(1.704). The lowest roughness values were observed when the clear strips were used regardless material type. The Sof-Lex system provided the lowest surface roughness values for all tested composite resins. Among composite resins the highest roughness values were found for Amelogen (G5­0.49 and G6­0.35), regardless polishing technique. All tested materials presented changes in color after immersion in coffee solution. The roughness surface and the staining of composite resins are material and polishing technique dependents.

Rugosidade e pigmentação de resinas são problemas comuns em odontologia. Objetivo: Avaliar influência das técnicas de um e múltiplos-passos de polimento na estabilidade de cor e rugosidade de resinas. Os grupos (n=10): G1.Filtek Supremo XT+Tira poliéster; G2.Filtek SupremeXT+PoGo; G3.Filtek Supreme XT+ Sof-Lex; G4.Amelogen+Tira poliéster; G5.Amelogen + PoGo; G6.Amelogen + Sof-Lex; G7.Tetric EvoCeram +Tira poliéster; G8.Tetric EvoCeram+PoGo; G9.Tetric EvoCeram+Sof-Lex; G10.CeramXDuo+Tira poliéster; G11.Ceram X Duo+PoGo; G12.Ceram X Duo+Sof-Lex. A Cor inicial e rugosidade foram determinadas antes e apóso polimento. Após, foram armazenadas durante 7 dias em solução de café e nova avaliação da cor foi realizada. Dois espécimes de cada grupo foram avaliados pela microscopia eletrônica de varredura. Dados de rugosidade e cor foram submetidos à ANOVA e teste Tukey (p <0,05). Todas as resinas testadas apresentaram alterações de cor após armazenamento em solução de café; foram observados os maiores valores de AE em tiras de poliésterpara as resinas,a seguir: G4 (9h)>G7 (5,8f) = G10 (5,7ef)>G1 (3,7c), seguindo-se a G6 (5,9f)>9 (3,1bc)=G12 (2,1ab)>G3 (1,7a). G3, após 7 dias, apresentaram os menores valores para AE (1,704). Menores valores de rugosidade foram observados para as tiras de poliéster, independentemente do material. Menores valores de rugosidade foram encontrados no sistema Sof-Lex. Entre as resinas valores maiores de rugosidade foram encontrados para Amelogen (G5-0,49 e G6-0,35), para as duas técnicas. Todos os materiais testados apresentaram alterações na cor após imersão em solução de café. A rugosidade e pigmentação das resinas compostas são dependentes da técnica e material.

Nine-year clinical evaluation of composite resins in Class III restorations / Avaliação de nove anos de restaurações de classe III em resina composta

The aim of this study was to evaluate thenine-year clinical performance of Class III composite restorations using two microhybrid anterior composite resins [Magic™-Vigodent/(F) and Z100™-3M ESPE/(Z)]. Material and Methods: The study was a randomized controlled trial, following the splitmouth design. Seventy restorations were placed, thirty-five for each resin composite into 35 patients. The restorations were placed by one operator according to the manufacturers’ specifications. Two independent evaluators conducted the clinical evaluation using modified USPHS criteria. After nine years, 56 restorations (28F-28Z) were evaluated. Data were analyzed using Chi-square, Exact Fisherand McNemar tests (p < 0.05). Results: Nopost operative sensitivity, secondary caries and loss of anatomic form was observed after nine-years for both composites. There were no significant differences between the two composites tested at baseline and after nine-years. Significant differen ces for Z and Frestorations between baseline and nine-year with respect to color matching and for F regarding themarginal integrity were detected. Conclusion: The clinical performance of both materials was consideredacceptable after the 9-year evaluation...

Objetivo: O objetivo deste estudo foi avaliar após nove anos a performance clínica de restaurações de classe III em resina composta, utilizando-se duas resinas microhíbridas para dentes anteriores [Magic-Vigodent/(F) e Z100-3M ESPE/(Z)]. Material e Métodos: Trata-se de um estudo clínico controlado aleatório, o qual utilizou o desenho de boca dividida.Setenta restaurações foram realizadas em trinta e cinco pacientes, sendo trinta e cinco para cada resina composta. As restaurações foram realizadas por um único operador seguindo as especificações dos fabricantes. Dois avaliadores independentes avaliaram as restaurações utilizando-se o critério USPHS modificado. Após nove anos, 56 restaurações(38F – 28Z) foram avaliadas. Os dados foram analisados por meio dos testes Qui-quadrado, Exato de Fisher e McNemar (p < 0,05). Resultados: Não foram detectados sensibilidade pós-operatória, cárie secundária e perda de forma anatômica no período analisado para ambas resinas. Não houve diferenças entre o período inicial e de nove anos para as resinas testadas, exceto para Z e F foram em relação à a cor e para a integridade do material para F. Conclusão: O comportamento clínico das duas resinas testadas foi considerado adequado após nove anos de avaliação...

Composite depth of cure using four polymerization techniques.

UNLABELLED: The light-curing technique is relevant to reduce the degree of polymerization shrinkage, improving clinical and esthetic success of composite resin restorations. OBJECTIVE: To evaluate in vitro the effect of four light-curing techniques on depth of cure of a composite resin. MATERIAL AND METHODS: Ten specimens of a composite resin were made in cylindrical cavities prepared in PVC plates (3.0 X 7.0 mm) for each light-curing technique. Four photoactivation methods were investigated: stepped, ramped, pulse-delay and traditional. Specimens were longitudinally sectioned and polished for microhardness measurements (kg/mm(2)), which were made at 0.1, 1.0, 2.0 and 4.0 mm from the irradiated surface. Data were subjected to ANOVA and Tukey's test. RESULTS: The effect of factors studied (curing method and distance from the surface) and the interaction of these factors was statistically significant (p<0.05). The traditional method of cure provided higher microhardness values (69.6 +/- 2.5) than the stepped (63.5 +/- 3.1) and pulsed (63.9 +/- 3.2) methods at all depths evaluated, but it did not differ from the ramped method (66.7+/- 4.4) at 0.1 and 1.0 mm of depth. CONCLUSION: All techniques employed provided satisfactory cure of the composite resin up to the depth of 2.0 mm from the irradiated surface.

Effect of deproteinization and tubular occlusion on microtensile bond strength and marginal microleakage of resin composite restorations.

UNLABELLED: Dentin adhesion procedure presents limitations, especially regarding to lifetime stability of formed hybrid layer. Alternative procedures have been studied in order to improve adhesion to dentin. OBJECTIVE: The aim of this study was to evaluate in vitro the influence of deproteinization or dentin tubular occlusion, as well as the combination of both techniques, on microtensile bond strength (microTBS) and marginal microleakage of composite resin restorations. MATERIAL AND METHODS: Extracted erupted human third molars were randomly divided into 4 groups. Dentin surfaces were treated with one of the following procedures: (A) 35% phosphoric acid gel (PA) + adhesive system (AS); (B) PA + 10% NaOCl + AS; (C) PA + oxalate + AS and (D) PA + oxalate + 10% NaOCl + AS. Bond strength data were analyzed statistically by two-way ANOVA and Tukey's test. The microleakage scores were analyzed using Kruskal-Wallis and Mann-Whitney non-parametric tests. Significance level was set at 0.05 for all analyses. RESULTS: microTBS data presented statistically lower values for groups D and B, ranking data as A>C>B>D. The use of oxalic acid resulted in microleakage reduction along the tooth/restoration interface, being significant when used alone. On the other hand, the use of 10% NaOCl alone or in combination with oxalic acid, resulted in increased microleakage. CONCLUSIONS: Dentin deproteinization with 10% NaOCl or in combination with oxalate significantly compromised both the adhesive bond strength and the microleakage at interface. Tubular occlusion prior to adhesive system application seems to be a useful technique to reduce marginal microleakage.

Effect of sealants in the composite surface roughness after tooth brushing / Efeito de selantes na rugosidade de resinas compostas após a escovação simulada

This in vitro study evaluated the influence of 4 surface sealers on the surface roughness of composite resins. Fifty specimens were divided into 10 groups, as follows: G1. (Control 1) Concept resin; G2. Concept + Fortify; G3. Concept + Biscover; G4. Concept + Lasting Touch; G5. Concept + Fill Glaze; G6. (Control 2) Esthet X; G7. Esthet X + Fortify; G8. Esthet X + Biscover; G9. Esthet X + Lasting Touch; G10. Esthet X + Fill Glaze. Specimens (15mm in length, 4 mm in depth and 5 mm in width) were made using a matrix and were stored in distilled water at 37ºC for 24 hours. After storage, specimens were polished using 320, 600 abrasive SiC paper under running water and the initial roughness was measured using a perfilometer. Surface sealers were applied and a new measurement of roughness was made. Specimens were submitted to 100,000 cycles of abrasive dentifrice brushing followed by another surface roughness measurement. Qualitative analysis was made by using SEM. Results were submitted to 3-way modified ANOVA (p<0.05) and Tukey's test. Results: Surface sealant provided smoother surfaces for both tested composite resins (G2=0.0727, G3=0.0147, G4=0.0307, G5=0.0253, G7=0.0173, G8=0.0333, G9=0.0480, G10=0,0480). After the abrasion test, the control group presented lower roughness surface (G1=0.0600, G6=0.1007). No statistical difference were found between Fortify (G2=0.0740, G7=0.0673) and Biscover (G7=0.0440). Lasting Touch presented rougher surfaces in relation to the other groups (G4= 0.1253, G9=0.0980), followed by Fill Glaze (G5=0.0933, G10= 0.0847). The application of surface sealant did not provide roughness optimization after tooth brushing simulation for the 2 composite resins tested.

Este estudo avaliou, in vitro, a influência de 4 selantes de superfície na rugosidade de duas resinas compostas. Cinqüenta espécimes foram confeccionados e divididos em 10 grupos com 5 espécimes cada, em função da combinação entre resina composta e selante de superfície, sendo: G1. Controle Concept; G2. Concept + Fortify; G3. Concept + Biscover; G4. Concept + Lasting Touch; G5. Concept + Fill Glaze; G6. Controle Esthet X; G7. Esthet X + Fortify; G8. Esthet X + Biscover; G9. Esthet X + Lasting Touch; G10. Esthet X + Fill Glaze. Os espécimes (15mm X 4 mm X 5 mm) foram confeccionados e armazenados em água destilada à 37ºC por 24 horas. Após este período, os espécimes foram planificados com lixas de granulometria 320, 600 e a rugosidade inicial foi aferida. Aplicaram-se os selantes de superfície e uma nova aferição da rugosidade superficial foi realizada. Os espécimes foram submetidos a 100.000 ciclos de escovação, seguido de nova mensuração da rugosidade. Os resultados foram submetidos aos testes ANOVA a 3 critérios e Tukey. A aplicação do selante de superfície diminuiu a rugosidade superficial das resinas compostas testadas (G2=0,0727, G3=0,0147, G4=0,0307, G5=0,0253, G6=0,0960, G7=0,0173, G8=0,0333, G9=0,0480). Nenhuma diferença estatística foi encontrada entre o grupo Fortify (G2=0,0740, G7=0,0673) e Biscover (G7=0,0440). Os maiores valores de rugosidade foram apresentados pelo grupo Lasting Touch (G4= 0,1253, G9=0,0980), seguido do Fill Glaze (G5=0,0933, G10= 0,0847). A aplicação do selante de superfície não otimizou a rugosidade das duas resinas compostas testadas após o teste de abrasão simulada.

Minimal alterations on the enamel surface by micro-abrasion: in vitro roughness and wear assessments

ABSTRACT Objective: To evaluate the in vitro changes on the enamel surface after a micro-abrasion treatment promoted by different products. Material and Methods: Fifty (50) fragments of bovine enamel (15 mm × 5 mm) were randomly assigned to five groups (n=10) according to the product utilized: G1 (control)= silicone polisher (TDV), G2= 37% phosphoric acid (3M/ESPE) + pumice stone (SS White), G3= Micropol (DMC Equipment), G4= Opalustre (Ultradent) and G5= Whiteness RM (FGM Dental Products). Roughness and wear were the responsible variables used to analyze these surfaces in four stages: baseline, 60 s and 120 s after the micro-abrasion and after polishing, using a Hommel Tester T1000 device. After the tests, a normal distribution of data was verified, with repeated ANOVA analyses (p≤0.05) which were used to compare each product in different stages. One-way ANOVA and Tukey tests were applied for individual comparisons between the products in each stage (p≤0.05). Results: Means and standard deviations of roughness and wear (µm) after all the promoted stages were: G1=7.26(1.81)/13.16(2.67), G2=2.02(0.62)/37.44(3.33), G3=1.81(0.91)/34.93(6.92), G4=1.92(0.29)/38.42(0.65) and G5=1.98(0.53)/33.45(2.66). At 60 seconds, all products tended to produce less surface roughness with a variable gradual decrease over time. After polishing, there were no statistically significant differences between the groups, except for G1. Independent of the product utilized, the enamel wear occurred after the micro-abrasion. Conclusions: In this in vitro study, enamel micro-abrasion presented itself as a conservative approach, regardless of the type of the paste compound utilized. These products promoted minor roughness alterations and minimal wear. The use of phosphoric acid and pumice stone showed similar results to commercial products for the micro-abrasion with regard to the surface roughness and wear. .

Clinical strategies for esthetic excellence in anterior tooth restorations: understanding color and composite resin selection

Direct composite resin restorations have become a viable alternative for patients that require anterior restorative procedures to be integrated to the other teeth that compose the smile, especially for presenting satisfactory esthetic results and minimum wear of the dental structure. Technological evolution along with a better understanding of the behavior of dental tissues to light incidence has allowed the development of new composite resins with better mechanical and optical properties, making possible a more artistic approach for anterior restorations. The combination of the increasing demand of patients for esthetics and the capacity to preserve the dental structure resulted in the development of different incremental techniques for restoring fractured anterior teeth in a natural way. In order to achieve esthetic excellence, dentists should understand and apply artistic and scientific principles when choosing color of restorative materials, as well as during the insertion of the composite resin. The discussion of these strategies will be divided into two papers. In this paper, the criteria for color and material selection to obtain a natural reproduction of the lost dental structures and an imperceptible restoration will be addressed.

Avaliação da sorção e solubilidade de uma resina composta em diferentes meios líquidos / Sorption and solubility assessment of a resin composite in different liquids

Este trabalho avaliou a sorção e a solubilidade de uma resina composta nanoparticulada em três meios líquidos diferentes: água destilada, Coca-Cola® e etanol/água a 75%, em função de dois períodos de armazenamentos: 7 e 15 dias. Foram confeccionados 30 espécimes, acondicionados em sílica gel azul, desidratada a 37°C, por 24 horas. Em seguida, foram pesados em balança analítica de precisão, repetindo-se até que se obtivesse massa constante (m1). Com a obtenção da m1, os espécimes foram subdivididos em 6 grupos e armazenados na solução. Três grupos permaneceram por 7 dias, e os outros três, por 15 dias. Após o período de armazenamento, os espécimes foram removidos, lavados, secos, pesados para a obtenção de uma segunda medida de massa, denominada m2. Os espécimes foram, então, recondicionados em estufa a 37°C. Mensurações de massa foram realizadas durante a desidratação, a cada 24 horas, obtendo-se a m3. Os dados de sorção e solubilidade foram calculados e submetidos à análise estatística. A resina nanoparticulada mostrou-se resistente à degradação química em meio ácido e em meio aquoso, mas foi suscetível à degradação, quando imerso em solução de etanol/água a 75%, apresentando solubilidade, sem diferença estatística entre os períodos de armazenamento.

This study evaluated the sorption and solubility of resin composite nanoparticle in three different liquid : distilled water, Coca-Cola ® and ethanol / water at 75%, according two periods of stores: 7 and 15 days. We prepared 30 specimens, packed in plastic container containing silica gel blue dehydrated and taken to an incubator at 37 ° C for 24 hours. Following, we weighed in analytical balance, and repeated until achieving constant mass (m1) on every 24 hour period. By getting the m1, the specimens were been divided into six groups and stored separately in 5 mL of each solution. Three groups were been maintained for 7 days and the other three for 15 days. After the storage period, the specimens were removed, washed, dried, weighed to obtain a second measure of mass, called m2. The specimens was reconditioned at 37 ° C. Mass measurements were performed during dehydration, every 24 hours, getting the dough reconditioned, with constant value of mass, called m3. The Data from sorption and solubility, we calculated and subjected to statistical analysis. The composite resin Filtek Z350 was found to be resistant to chemical degradation in acid and aqueous, but was susceptible to degradation when immersed in a solution of ethanol / water at 75%, with solubility, no statistical difference between the periods of storage.

Seleção de cor e estratificação natural para reabilitação estética de dente anterior / Color selectiona and natural layering for aesthetic reproduction of anterior teetf

Em função da excelência em estética e desgaste mínimo da estrutura dentária, as resinas compostas ocupam uma posição de destaqque entre os materiais restauradores atuais. As novas resinas compsotas associadas ao melhor antendimento do comportamento dos tecidos dentários frente à incidência de luz permitem a estratificação natural dos dentes. A estratificação natural consiste em uma abordagem simples e efetiva para o emprego das resinas compostas nas restaurações, de modo a torná-las miméticas com a aparência natural do substrato dentário. Compreender e implementar princípios artísticos e científicos na escolha da cor dos materiais restauradores e a adequada inserção da resina composta, contudo, é imprescindível. Os passos operatórios para obter o sucesso restaurador com esse material serão descritos no relato do caso clínico.

Because of the excellence in aesthetics and minimal wear of the tooth structure, composite resins hold a prominent position among the current restorative materials. The new composite resins associated with better understanding of the behavior of dental tissues facing the incidence of light allows the natural stratification of teeth. This natural stratification consists of a simple and effective approach to the use of composite resins in restoration in order to make them mimetic with the natural appearance of the tooth substrate. Understanding and to implementing scientific and artistic principles in choosing the color of restorative materials and the proper insertion of the composite, however, is essential. The operative steps for success with this restorative material will be described in a clinical case report.

Resistência à tração de pinos de fibra de vidro intrarradiculares: efeito de diferentes agentes cimentantes / Tensile strength of glass fiber posts in the intraradicular environment: effect of different luting cements

Avaliou-se, in vitro, a força de remoção por tração dos pinos de fibra de vidro (WP) de 1,2mm (White Post DC, FGM ), cimentados com 3 diferentes agentes de cimentação: cimento de fosfato de zinco (FZ) (S.S.WHITE); cimento resinoso dual (V) (Variolink, Ivoclar/ Vivadent) e cimento resinoso de polimerização química (M) (Multilink, Ivoclar/ Vivadent). Foram utilizados 45 dentes humanos unirradiculares e as coroas removidas 3 mm aquém da junção amelo-cementária. Os grupos foram divididos em função do agente de cimentação, a seguir: G1 (controle)- WP+FZ (n=15); G2- WP+V (n=15) e G3-WP+M(n=15). As raízes foram incluídas em resina acrílica autopolimerizável. Os espécimes foram armazenados em água destilada a 37º C, por 7 dias e submetidos ao teste de remoção por tração em uma máquina de ensaio mecânico MTS 810 (MTS System Corporation), com velocidade de 0,5 mm/min. As médias obtidas foram: FZ (95.1200 MPa); V (87.0680 MPa) e M (73.0500 MPa). Os resultados foram submetidos ao teste estatístico ANOVA e Tukey (p<0,05%). Concluiu-se que o grupo dos pinos de fibra de vidro cimentados com fosfato de zinco apresentou os maiores valores de resistência à remoção por tração, mas estatisticamente diferente somente para o grupo do Multilink.

This study evaluated, in vitro, the tensile stength of glass fiber post (WP), de 1.2mm, (White Post DC, FGM) cemented with three different luting agents: zinc phosphate cement (FZ) (S.S.WHITE); dual-polymerized resin luting agents (V) (Variolink, Ivoclar/ Vivadent) and autopolymerized resin luting agents (M) (Multilink, Ivoclar/ Vivadent). Forty-five human anterior teeth had the crowns removed 3 mm on this side at the cement-enamel junction. They were divide into 3 groups, as follows: G1- (control) WP+FZ (n=15); G2- WP+V (n=15) e G3-WP+M (n=15). The roots were mounted vertically in self-cured acrylic resin. The specimens were stored in destilled water for one week at 37ºC and fixed in a testing machine MTS 810 (MTS System Corporation) and loaded in tension at a cross-head speed of 0.5 mm/min until failure. The results were: zinc phosphate cement (95.1200 MPa); Variolink (87.0680 MPa) and Multilink (73.0500 MPa). The data was analyzed using ANOVA and Tukey tests at the 0.05 significance level. It was possible conclude that the glass fiber posts cimented with zinc phosphate cement presented the largest resistance values for the tension's removal, but significant different only for the Multilink's group.

Tratamiento de la pigmentación sistémica y la fluorosis por medio de blanqueamiento en consultorio asociado a microabrasión de esmalte / Treatment of systemic pigmentation and fluorosis through associated office bleaching enamel microabrasion

La resolución estética de los más diversos tipos de alteraciones de color de los dientes representa un gran desafío para el odontólogo. A través del correcto diagnóstico de estas alteraciones, el profesional puede decidir cuál es el mejor tratamiento estético u optar por la asociación de diferentes métodos de tratamiento a fin de alcanzar un resultado estético satisfactorio con un mínimo desgaste de las estructuras dentales. En la tentativa de promover mejoras en la estética de la sonrisa, el profesional puede usar el blanqueamiento dental en combinación con la microabrasión del esmalte como una opción segura y eficaz para la solución de algunas manchas. En el caso clínico presentado, las técnicas de blanqueamiento en consultorio con energía híbrida LASER/LED y la microabrasión del esmalte con pasta de ácido fosfórico 37% y piedra pómez fueron utilizadas para establecer un color armónico en los dientes que presentaban de pigmentación sistémica y fluorosis dental

The esthetic treatment of color alterations in dental organ meant a great challenge to the profession. By means of a comprehensive diagnostic, clinicians have to decide which the best esthetic solution is or to associate several methods in order to achieve a satisfactory esthetic treatment through a conservative approach. In an attempt to provide esthetic improvement, clinicians can combine bleaching and enamel microabrasion therapies as a safe and effective measure to solve dental staining. In this clinical case, bleaching at the dental office with hybrid LASER/LED energy and enamel microabrasion with 37% phosphoric acid and pumice paste were used to establish color harmony in teeth affected by systemic pigmentation and dental fluorosis

Composite depth of cure using four polymerization techniques

The light-curing technique is relevant to reduce the degree of polymerization shrinkage, improving clinical and esthetic success of composite resin restorations. OBJECTIVE: To evaluate in vitro the effect of four light-curing techniques on depth of cure of a composite resin. MATERIAL AND METHODS: Ten specimens of a composite resin were made in cylindrical cavities prepared in PVC plates (3.0 X 7.0 mm) for each light-curing technique. Four photoactivation methods were investigated: stepped, ramped, pulse-delay and traditional. Specimens were longitudinally sectioned and polished for microhardness measurements (kg/mm²), which were made at 0.1, 1.0, 2.0 and 4.0 mm from the irradiated surface. Data were subjected to ANOVA and Tukey's test. RESULTS: The effect of factors studied (curing method and distance from the surface) and the interaction of these factors was statistically significant (p<0.05). The traditional method of cure provided higher microhardness values (69.6 ± 2.5) than the stepped (63.5 ± 3.1) and pulsed (63.9 ± 3.2) methods at all depths evaluated, but it did not differ from the ramped method (66.7± 4.4) at 0.1 and 1.0 mm of depth. CONCLUSION: All techniques employed provided satisfactory cure of the composite resin up to the depth of 2.0 mm from the irradiated surface.

Effect of deproteinization and tubular occlusion on microtensile bond strength and marginal microleakage of resin composite restorations

Dentin adhesion procedure presents limitations, especially regarding to lifetime stability of formed hybrid layer. Alternative procedures have been studied in order to improve adhesion to dentin. OBJECTIVE: The aim of this study was to evaluate in vitro the influence of deproteinization or dentin tubular occlusion, as well as the combination of both techniques, on microtensile bond strength (µTBS) and marginal microleakage of composite resin restorations. MATERIAL AND METHODS: Extracted erupted human third molars were randomly divided into 4 groups. Dentin surfaces were treated with one of the following procedures: (A) 35 percent phosphoric acid gel (PA) + adhesive system (AS); (B) PA + 10 percent NaOCl + AS; (C) PA + oxalate + AS and (D) PA + oxalate + 10 percent NaOCl + AS. Bond strength data were analyzed statistically by two-way ANOVA and Tukey's test. The microleakage scores were analyzed using Kruskal-Wallis and Mann-Whitney non-parametric tests. Significance level was set at 0.05 for all analyses. RESULTS: µTBS data presented statistically lower values for groups D and B, ranking data as A>C>B>D. The use of oxalic acid resulted in microleakage reduction along the tooth/restoration interface, being significant when used alone. On the other hand, the use of 10 percent NaOCl alone or in combination with oxalic acid, resulted in increased microleakage. CONCLUSIONS: Dentin deproteinization with 10 percent NaOCl or in combination with oxalate significantly compromised both the adhesive bond strength and the microleakage at interface. Tubular occlusion prior to adhesive system application seems to be a useful technique to reduce marginal microleakage.