Preservation in Young Patients of Pulp Vitality and Anatomical-Functional Restoration of the Lost Structure.

Often, young patients (≤30 years old) present with carious lesions that progress acutely, compromising a large amount of tooth structure. In these cases, a treatment to prevent the occurrence of pulp exposure and promote remineralization of caries-affected dentin is necessary to maintain healthy dental structure and allow more conservative interventions. The approach will be different when pulp exposure occurs: The therapeutic treatments will be focused on reparative dentin formation and prevention of microorganisms penetrating the pulp organ. Due to the different possible treatments that can be performed to avoid pulp necrosis and the various materials that can be used for this purpose, professionals may have some difficulties understanding all the indications for conservative pulp treatments. The objective of this article is to describe and discuss a successful pulp capping and stepwise excavation associated with restorative treatment for deep caries lesions of anterior upper teeth.

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.

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...

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.

Soluções estéticas para alterações intrínsecas do esmalte dentário / Aesthetic solution for intrinsic alterations of dental enamel

A alta expectativa por tratamentos estéticos gerada pelos pacientes, associada a uma Odontologia cada vez menos invasiva, torna o tratamento das lesões intrínsecas de esmalte um desafio para o clínico. Desta forma, existe a necessidade da constante atualização e discussão sobre o tema para oferecer o tratamento mais conservador e, ao mesmo tempo, de excelência. Neste artigo serão apresentados e discutidos alguns casos clínicos representativos de situações mais frequentes de alterações do esmalte dentário, em que foram empregados diferentes tratamentos, desde os mais conservadores até os que envolvem algum desgaste dentário, visando o restabelecimento estético e funcional do esmalte.

The high expectations of the patients for aesthetic treatments associated to a less invasive Dentistry turns treatment of intrinsic lesions of enamel a challenge for clinicians. Thus constant update and discussion are needed in order to offer a more conservative approach and, at the same time, an excellent treatment. The present paper will present and discuss some clinical cases representing the most frequent situations of tooth enamel alterations, in which different treatments have been used, from the most conservative to those involving some tooth drilling, aiming at aesthetic and functional restoration of the enamel.

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.

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. .

The influence of "C-factor" and light activation technique on polymerization contraction forces of resin composite

OBJECTIVES: This study evaluated the influence of the cavity configuration factor ("C-Factor") and light activation technique on polymerization contraction forces of a Bis-GMA-based composite resin (Charisma, Heraeus Kulzer). MATERIAL AND METHODS: Three different pairs of steel moving bases were connected to a universal testing machine (emic DL 500): groups A and B - 2x2 mm (CF=0.33), groups C and D - 3x2 mm (CF=0.66), groups e and F - 6x2 mm (CF=1.5). After adjustment of the height between the pair of bases so that the resin had a volume of 12 mm³ in all groups, the material was inserted and polymerized by two different methods: pulse delay (100 mW/cm² for 5 s, 40 s interval, 600 mW/cm² for 20 s) and continuous pulse (600 mW/cm² for 20 s). Each configuration was light cured with both techniques. Tensions generated during polymerization were recorded by 120 s. The values were expressed in curves (Force(N) x Time(s)) and averages compared by statistical analysis (ANOVA and Tukey's test, p<0.05). RESULTS: For the 2x2 and 3x2 bases, with a reduced C-Factor, significant differences were found between the light curing methods. For 6x2 base, with high C-Factor, the light curing method did not influence the contraction forces of the composite resin. CONCLUSIONS: Pulse delay technique can determine less stress on tooth/restoration interface of adhesive restorations only when a reduced C-Factor is present.

Impact of filler size and distribution on roughness and wear of composite resin after simulated toothbrushing.

OBJECTIVES: Nanofilled composite resins are claimed to provide superior mechanical properties compared with microhybrid resins. Thus, the aim of this study was to compare nanofilled with microhybrid composite resins. The null hypothesis was that the size and the distribution of fillers do not influence the mechanical properties of surface roughness and wear after simulated toothbrushing test. MATERIAL AND METHODS: Ten rectangular specimens (15 mm x 5 mm x 4 mm) of Filtek Z250 (FZ2), Admira (A), TPH3 (T),Esthet-X (EX), estelite sigma (ES), concept advanced (C), Grandio (G) and Filtek Z350 (F) were prepared according to manufacturer's instructions. Half of each top surface was protected with nail polish as control surface (not brushed) while the other half was assessed with five random readings using a roughness tester (Ra). Following, the specimens were abraded by simulated toothbrushing with soft toothbrushes and slurry comprised of 2:1 water and dentifrice (w/w). 100,000 strokes were performed and the brushed surfaces were reanalyzed. Nail polish layers were removed from the specimens so that the roughness (Ra) and the wear could be assessed with three random readings (µm). Data were analyzed by ANOVA and Tukey's multiple-comparison test (α=0.05). RESULTS: Overall outcomes indicated that composite resins showed a significant increase in roughness after simulated toothbrushing, except for Grandio, which presented a smoother surface. Generally, wear of nanofilled resins was significantly lower compared with microhybrid resins. CONCLUSIONS: As restorative materials suffer alterations under mechanical challenges, such as toothbrushing, the use of nanofilled materials seem to be more resistant than microhybrid composite resins, being less prone to be rougher and worn.

Impact of filler size and distribution on roughness and wear of composite resin after simulated toothbrushing

OBJECTIVES: Nanofilled composite resins are claimed to provide superior mechanical properties compared with microhybrid resins. Thus, the aim of this study was to compare nanofilled with microhybrid composite resins. The null hypothesis was that the size and the distribution of fillers do not influence the mechanical properties of surface roughness and wear after simulated toothbrushing test. MATERIAL AND METHODS: Ten rectangular specimens (15 mm x 5 mm x 4 mm) of Filtek Z250 (FZ2), Admira (A), TPH3 (T),Esthet-X (EX), Estelite Sigma (ES), Concept Advanced (C), Grandio (G) and Filtek Z350 (F) were prepared according to manufacturer's instructions. Half of each top surface was protected with nail polish as control surface (not brushed) while the other half was assessed with five random readings using a roughness tester (Ra). Following, the specimens were abraded by simulated toothbrushing with soft toothbrushes and slurry comprised of 2:1 water and dentifrice (w/w). 100,000 strokes were performed and the brushed surfaces were reanalyzed. Nail polish layers were removed from the specimens so that the roughness (Ra) and the wear could be assessed with three random readings (µm). Data were analyzed by ANOVA and Tukey's multiple-comparison test (α=0.05). RESULTS: Overall outcomes indicated that composite resins showed a significant increase in roughness after simulated toothbrushing, except for Grandio, which presented a smoother surface. Generally, wear ofnanofilled resins was significantly lower compared with microhybrid resins. CONCLUSIONS: As restorative materials suffer alterations under mechanical challenges, such as toothbrushing, the use of nanofilled materials seem to be more resistant than microhybrid composite resins, being less prone to be rougher and worn.

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.

Effect of light sources and curing mode techniques on sorption, solubility and biaxial flexural strength of a composite resin.

UNLABELLED: Adequate polymerization plays an important role on the longevity of the composite resin restorations. OBJECTIVES: The aim of this study was to evaluate the effect of light-curing units, curing mode techniques and storage media on sorption, solubility and biaxial flexural strength (BFS) of a composite resin. MATERIAL AND METHODS: Two hundred and forty specimens were made of one composite resin (Esthet-X) in a stainless steel mold (2 mm x 8 mm Ø), and divided into 24 groups (n=10) established according to the 4 study factors: light-curing units: quartz tungsten halogen (QTH) lamp and light-emitting diodes (LED); energy densities: 16 J/cm² and 20 J/cm²; curing modes: conventional (CM) and pulse-delay (PD); and permeants: deionized water and 75% ethanol for 28 days. Sorption and solubility tests were performed according to ISO 4049:2000 specifications. All specimens were then tested for BFS according to ASTM F394-78 specification. Data were analyzed by three-way ANOVA followed by Tukey, Kruskal-Wallis and Mann-Whitney tests (α=0.05). RESULTS: In general, no significant differences were found regarding sorption, solubility or BFS means for the light-curing units and curing modes (p>0.05). Only LED unit using 16 J/cm² and PD using 10 s produced higher sorption and solubility values than QTH. Otherwise, using CM (16 J/cm²), LED produced lower values of BFS than QTH (p<0.05). 75% ethanol permeant produced higher values of sorption and solubility and lower values of BFS than water (p<0.05). CONCLUSION: Ethanol storage media produced more damage on composite resin than water. In general the LED and QTH curing units using 16 and 20 J/cm² by CM and PD curing modes produced no influence on the sorption, solubility or BFS of the tested resin.

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.

Effect of light sources and curing mode techniques on sorption, solubility and biaxial flexural strength of a composite resin

Adequate polymerization plays an important role on the longevity of the composite resin restorations. OBJECTIVES: The aim of this study was to evaluate the effect of light-curing units, curing mode techniques and storage media on sorption, solubility and biaxial flexural strength (BFS) of a composite resin. MATERIAL AND METHODS: Two hundred and forty specimens were made of one composite resin (Esthet-X) in a stainless steel mold (2 mm x 8 mm Ø), and divided into 24 groups (n=10) established according to the 4 study factors: light-curing units: quartz tungsten halogen (QTH) lamp and light-emitting diodes (LED); energy densities: 16 J/cm² and 20 J/cm²; curing modes: conventional (CM) and pulse-delay (PD); and permeants: deionized water and 75% ethanol for 28 days. Sorption and solubility tests were performed according to ISO 4049:2000 specifications. All specimens were then tested for BFS according to ASTM F394-78 specification. Data were analyzed by three-way ANOVA followed by Tukey, Kruskal-Wallis and Mann-Whitney tests (α=0.05). RESULTS: In general, no significant differences were found regarding sorption, solubility or BFS means for the light-curing units and curing modes (p>0.05). Only LED unit using 16 J/cm² and PD using 10 s produced higher sorption and solubility values than QTH. Otherwise, using CM (16 J/cm²), LED produced lower values of BFS than QTH (p<0.05). 75% ethanol permeant produced higher values of sorption and solubility and lower values of BFS than water (p<0.05). CONCLUSION: Ethanol storage media produced more damage on composite resin than water. In general the LED and QTH curing units using 16 and 20 J/cm² by CM and PD curing modes produced no influence on the sorption, solubility or BFS of the tested resin.

The influence of "C-factor" and light activation technique on polymerization contraction forces of resin composite.

OBJECTIVES: This study evaluated the influence of the cavity configuration factor ("C-Factor") and light activation technique on polymerization contraction forces of a Bis-GMA-based composite resin (Charisma, Heraeus Kulzer). MATERIAL AND METHODS: Three different pairs of steel moving bases were connected to a universal testing machine (emic DL 500): groups A and B - 2x2 mm (CF=0.33), groups C and D - 3x2 mm (CF=0.66), groups e and F - 6x2 mm (CF=1.5). After adjustment of the height between the pair of bases so that the resin had a volume of 12 mm³ in all groups, the material was inserted and polymerized by two different methods: pulse delay (100 mW/cm² for 5 s, 40 s interval, 600 mW/cm² for 20 s) and continuous pulse (600 mW/cm² for 20 s). Each configuration was light cured with both techniques. Tensions generated during polymerization were recorded by 120 s. The values were expressed in curves (Force(N) x Time(s)) and averages compared by statistical analysis (ANOVA and Tukey's test, p<0.05). RESULTS: For the 2x2 and 3x2 bases, with a reduced C-Factor, significant differences were found between the light curing methods. For 6x2 base, with high C-Factor, the light curing method did not influence the contraction forces of the composite resin. CONCLUSIONS: Pulse delay technique can determine less stress on tooth/restoration interface of adhesive restorations only when a reduced C-Factor is present.

Conservative approaches for the management of failed resin-based posterior restorations: a case report.

Composite resin restorations have been shown to be functionally reliable and esthetically acceptable to patients, primarily due to improvements in their chemicophysical characteristics. Nevertheless, clinical limitations, such as marginal discoloration, disadaptation, and microleakage, are observed in some patients with these restorations. The choice of treatment pursued to repair such restorations depends primarily on the analysis of the compromised restoration with regard to these aforementioned imperfections. The most common procedures invoked to treat compromised restorations include resurfacing, repairing the restoration with or without the use of surface sealants, and completely replacing the compromised restoration. This case report describes the proper implementation of a simple technique, known as composite resin posterior restoration, that yields a satisfactory outcome for patients who have been characterized with these clinical limitations.

Accuracy of Single-Step versus 2-Step Double-Mix Impression Technique.

Objective. To investigate the accuracy of dies obtained from single-step and 2-step double-mix impressions. Material and Methods. Impressions (n = 10) of a stainless steel die simulating a complete crown preparation were performed using a polyether (Impregum Soft Heavy and Light body) and a vinyl polysiloxane (Perfectim Blue Velvet and Flexi-Velvet) in two consistencies, in one or two (without relief) steps. Accuracy of the stone dies was accessed at a measuring microscope, using a metallic crown with perfect fit to the reference crown preparation. Data were submitted to 2-way ANOVA and Tukey test (α = 0.05). Results. The single-step technique resulted in slightly larger dies, while the 2-step technique without relief produced significantly smaller dies, when compared to the original stainless steel die. Stone dies obtained from 2-step polyether impressions were significantly smaller when compared to dies obtained from 2-step vinyl polysiloxane impressions (Impregum 2-step: -290.94 ± 71.64 µm; Perfectim 2-step: -201.86 ± 28.58 µm). No significant differences were observed in dies obtained from either polyether or vinyl polysiloxane with the single-step technique (Impregum single-step: 63.52 ± 16.60 µm; Perfectim single-step: 79.40 ± 14.11 µm). Conclusion. Higher discrepancies were detected for the 2-step impression technique without relief for the investigated materials.

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.

Tratamento da agenesia de incisivos laterais superiores: só Ortodontia basta? / Treatment of congenitally missing lateral incisors: Orthodontics is enough?

A ausência congênita de um ou mais dentes constitui uma anomalia de desenvolvimento nos humanos, com influência de fatores filogenéticos, sendo frequente nos incisivos laterais superiores, não obstante a agenesia dos terceiros molares apresentar a mais alta prevalência. Entretanto, do ponto de vista clínico, a ocorrência da falta de elementos dentários na região anterior implica em alteração morfofuncional, com comprometimento estético e, consequentemente, da harmonia do sorriso. A literatura odontológica tem evidenciado algumas opções de tratamento, destacando a contribuição da movimentação ortodôntica para o redimensionamento do espaço e adequação restauradora estética. Na grande maioria dos casos, a recomposição ou realinhamento dos dentes anteriores merece uma abordagem interdisciplinar, com associação de procedimento cirúrgico-restaurador. Para referenciar tal situação clínica, o presente trabalho tem por objetivo apresentar o tratamento de agenesia bilateral de incisivos laterais superiores, adotando-se uma abordagem ortodôntica inicial para promover fechamento de espaço na área edêntula, com concomitante abordagem periodontal e finalização do contexto estético e cosmético, por meio da reanatomização dos caninos e incisivos centrais.

Influence of curing rate on softening in ethanol, degree of conversion, and wear of resin composite.

PURPOSE: To investigate the effect of curing rate on softening in ethanol, degree of conversion, and wear of resin composites. METHOD: With a given energy density and for each of two different light-curing units (QTH or LED), the curing rate was reduced by modulating the curing mode. Thus, the irradiation of resin composite specimens (Filtek Z250, Tetric Ceram, Esthet-X) was performed in a continuous curing mode and in a pulse-delay curing mode. Wallace hardness was used to determine the softening of resin composite after storage in ethanol. Degree of conversion was determined by infrared spectroscopy (FTIR). Wear was assessed by a three-body test. Data were submitted to Levene's test, one and three-way ANOVA, and Tukey HSD test (alpha = 0.05). RESULTS: Immersion in ethanol, curing mode, and material all had significant effects on Wallace hardness. After ethanol storage, resin composites exposed to the pulse-delay curing mode were softer than resin composites exposed to continuous cure (P< 0.0001). Tetric Ceram was the softest material followed by Esthet-X and Filtek Z250 (P< 0.001). Only the restorative material had a significant effect on degree of conversion (P< 0.001): Esthet-X had the lowest degree of conversion followed by Filtek Z250 and Tetric Ceram. Curing mode (P= 0.007) and material (P< 0.001) had significant effect on wear. Higher wear resulted from the pulse-delay curing mode when compared to continuous curing, and Filtek Z250 showed the lowest wear followed by Esthet-X and Tetric Ceram.