Caries progression in non-cavitated fissures after infiltrant application: a 3-year follow-up of a randomized controlled clinical trial.

OBJECTIVES: To evaluate the efficacy of a conservative treatment to prevent the progression of caries using an infiltrant on non-cavitated pit and fissures. MATERIAL AND METHODS: This controlled clinical trial selected 23 volunteers with clinically and radiographically non-cavitated occlusal caries among patients presenting a "rather low" to "very high" caries risk. Eighty-six teeth were randomly divided into two experimental groups: teeth receiving a commercial pit-and-fissure sealant (Alpha Seal-DFL) and contralateral teeth receiving Icon infiltrant (DMG). Caries progression was monitored by clinical (laser fluorescence caries detection) and radiographic examination at 12-month intervals over a period of 3 years of monitored caries progression. Probing the sealing materials to detect areas of retention was also used to evaluate marginal integrity. RESULTS: Statistical analysis showed no difference in caries progression using laser fluorescence caries detection when both materials were compared, regardless of the evaluation times (p>0.05). No significance was observed when the marginal sealant integrity of both materials was compared, regardless of the evaluation time (p<0.05). Marginal integrity significantly reduced after 1 year for both materials (p<0.05), but remained stable after 2 and 3 years of evaluation, compared with 1-year results (p>0.05). SEM analysis exhibited a more homogeneous sealing for the infiltrant than obtained by the sealant. CONCLUSIONS: The infiltrant was effective to prevent the caries progression in non-cavitated pit-and-fissures after 3 years of clinical evaluation, comparable with the conventional sealant. The infiltrant also presented better results in terms of caries progression at the 3-year evaluation time using the radiographic analysis.

Caries progression in non-cavitated fissures after infiltrant application: a 3-year follow-up of a randomized controlled clinical trial

Abstract Objectives To evaluate the efficacy of a conservative treatment to prevent the progression of caries using an infiltrant on non-cavitated pit and fissures. Material and Methods This controlled clinical trial selected 23 volunteers with clinically and radiographically non-cavitated occlusal caries among patients presenting a "rather low" to "very high" caries risk. Eighty-six teeth were randomly divided into two experimental groups: teeth receiving a commercial pit-and-fissure sealant (Alpha Seal-DFL) and contralateral teeth receiving Icon infiltrant (DMG). Caries progression was monitored by clinical (laser fluorescence caries detection) and radiographic examination at 12-month intervals over a period of 3 years of monitored caries progression. Probing the sealing materials to detect areas of retention was also used to evaluate marginal integrity. Results Statistical analysis showed no difference in caries progression using laser fluorescence caries detection when both materials were compared, regardless of the evaluation times (p>0.05). No significance was observed when the marginal sealant integrity of both materials was compared, regardless of the evaluation time (p<0.05). Marginal integrity significantly reduced after 1 year for both materials (p<0.05), but remained stable after 2 and 3 years of evaluation, compared with 1-year results (p>0.05). SEM analysis exhibited a more homogeneous sealing for the infiltrant than obtained by the sealant. Conclusions The infiltrant was effective to prevent the caries progression in non-cavitated pit-and-fissures after 3 years of clinical evaluation, comparable with the conventional sealant. The infiltrant also presented better results in terms of caries progression at the 3-year evaluation time using the radiographic analysis.

Effects of typified propolis on mutans streptococci and lactobacilli: a randomized clinical trial.

OBJECTIVE: The aim of this study was to determine in a randomized, double-blind, placebo-controlled clinical trial the effects of typified propolis and chlorhexidine rinses on salivary levels of mutans streptococci (MS) and lactobacilli (LACT). METHODS: One hundred patients were screened for salivary levels of MS >100,000 CFUs/mL of saliva. All patients presented with at least one cavitated decayed surface. Sixty patients met entry criteria. Subjects were adults 18-55 years old. After restoration of cavitated lesions patients were randomized to 3 experimental groups: 1) PROP-alcohol-free 2% typified propolis rinse (n = 20); 2) CHX- 0.12% chlorhexidine rinse; 3) PL-placebo mouthrinse. Patients rinsed unsupervised 15 mL of respective rinses twice a day for 1 min for 28 days. Patients were assessed for the salivary levels of MS (Dentocult SM) and LACT (Dentocult LB) at baseline, 7-day, 14-day, and at 28-day visits (experimental effects) and at 45-day visit (residual effects). General linear models were employed to analyze the data. RESULTS: PROP was superior to CHX at 14-day and 28-day visits in suppressing the salivary levels of MS (p < .05). PROP was superior to PL at all visits (p < .01). The residual effects of PROP in suppressing the salivary levels of MS could still be observed at the 45-day visit, where significant differences between PROP and CHX (p < .05), were demonstrated. PROP was significantly superior than CHX in suppressing the levels of salivary LACT at the 28-day visit (p < .05). CONCLUSION: Typified propolis rinse was effective in suppressing cariogenic infections in caries-active patients when compared to existing and placebo therapies.

Effects of typified propolis on mutans streptococci and lactobacilli: a randomized clinical trial / Efeitos da própolis tipificada nos estreptococcos do grupo mutans e lactobacilos: ensaio clínico randomizado

Objective: The aim of this study was to determine in a randomized, double-blind, placebo-controlled clinical trial the effects of typified propolis and chlorhexidine rinses on salivary levels of mutans streptococci (MS) and lactobacilli (LACT). Methods: One hundred patients were screened for salivary levels of MS >100,000 CFUs/mL of saliva. All patients presented with at least one cavitated decayed surface. Sixty patients met entry criteria. Subjects were adults 18-55 years old. After restoration of cavitated lesions patients were randomized to 3 experimental groups:1) PROP-alcohol-free 2% typified propolis rinse (n= 20); 2) CHX- 0.12% chlorhexidine rinse; 3) PLplacebo mouthrinse. Patients rinsed unsupervised 15 mL of respective rinses twice a day for 1 min for 28 days. Patients were assessed for the salivary levels of MS (Dentocult SM) and LACT (Dentocult LB) at baseline, 7-day, 14-day, and at 28-day visits (experimental effects) and at 45-day visit (residual effects). General linear models were employed to analyze the data. Results: PROP was superior to CHX at 14-day and 28-day visits in suppressing the salivary levels of MS (p < .05). PROP was superior to PL at all visits (p < .01). The residual effects of PROP in suppressing the salivary levels of MS could still be observed at the 45-day visit, where significant differences between PROP and CHX (p < .05), were demonstrated. PROP was significantly superior than CHX in suppressing the levels of salivary LACT at the 28-day visit (p < .05). Conclusion: Typified propolis rinse was effective in suppressing cariogenic infections in caries-active patients when compared to existing and placebo therapies.

Objetivo: O objetivo deste estudo foi determinar, em um estudo randomizado, duplo-cego, placebo-controlado os efeitos da própolis tipificada e clorexidina sobre os níveis salivares de estreptococos do grupo mutans (EM) e lactobacilos (LACT). Métodos: Cem pacientes foram selecionados para níveis salivares de MS > 100.000 UFC/mL de saliva. Todos os pacientes apresentaram pelo menos uma superfície cariada com cavitação. Sessenta pacientes preencheram os critérios de inclusão. Os indivíduos eram adultos com 18-55 anos de idade. Após a restauração das lesões cavitadas, os pacientes foram randomizados para três grupos experimentais: 1) PROP- bochecho livre de álcool de 2% de própolis tipificada (n = 20), 2) CHX- bochecho de clorexidina 0,12%, 3) PL- bochecho placebo. Os participantes bochecharam sem supervisão 15 mL dos enxaguatórios duas vezes por dia, durante 1 minuto, durante 28 dias. Os pacientes foram avaliados para os níveis salivares de MS (Dentocult SM) e LACT (Dentocult LB) na linha de base, e após 7 dias, 14 dias, 28 dias (efeitos experimentais) e 45 dias (efeitos residuais). Modelos lineares foram utilizados para analisar os dados. Resultados: PROP foi superior ao CHX nas visitas de 14 dias e de 28 dias na supressão dos níveis salivares de SM (p < 0,05). PROP foi superior ao PL em todas as visitas (p < 0,01). Os efeitos residuais de PROP na supressão dos níveis salivares de MS ainda foi observado na visita de 45 dias, onde diferenças significativas entre PROP e CHX (p < 0,05) foram demonstradas. PROP foi significativamente superior a CHX na supressão dos níveis salivares de LACT na visita de 28 dias (p < 0,05). Conclusão: O enxaguatório de própolis tipificada foi eficaz na supressão de infecções cariogênicas em pacientes com atividade de cárie quando comparado a terapias existentes e ao placebo

Comparative study of bond strength to human and bovine dentine at three different depths / Estudo comparativo da resistência adesiva à dentina humana e bovina em três diferentes profundidades

The aim of this study was to compare the bond strength to three different depths of remaining human and bovine dentin, through shear bond strength test, and to establish a possible relationship among the depths of the substrates to contribute for the replacement of human dentin in bond strength tests. Forty-eight human teeth (H) and forty-eight bovine teeth (B), freshly extracted, stored in distilled water and frozen at -18 ° C for at most four weeks were used in this study. 240-, 400-, 600- and 800-grit sandpapers were used to expose the dentin and standardize the smear layer at 0.5, 1.0 and 2.0mm of dentin thickness. Scotchbond Multi-Purpose Plus adhesive system was used following the manufacturer’s instructions, on a standardized area of 4mm, followed by the incrementally application of Z100 resin composite (3M). The shear bond test was performed in the Instron Universal machine at cross-head speed of 0.5mm/min. Statistical analysis was performed by ANOVA (p <0.05). There were significant differences in bond strength between H and B teeth, with the highest values for H teeth. There was a significant difference in bond strength to the depths analyzed but there was similarity in behavior between H (0.5mm) and B (2mm) substrates. Bovine substrate can be used for laboratory studies of bond strength as indicative of the initial performance of new products, although the differences related to human substrate should be observed.

O objetivo do presente estudo foi comparar a resistência adesiva da dentina humana e bovina em três diferentes espessuras de remanescente, frente ao teste de cisalhamento, a fim de estabelecer uma possível relação de profundidade entre os substratos visando contribuir para a substituição da dentina humana em testes de adesão. Empregaram-se 48 dentes humanos (H) e 48 dentes bovinos (B), recém-extraídos, armazenados em água destilada e congelados a –18°C, por no máximo quatro semanas. Foram utilizadas lixas de granulação 240, 400, 600 e 800, para expor a dentina e padronizar a smear layer, com espessura de dentina de 0,5, 1,0 e 2,0mm. O sistema adesivo Scotchbond Multi-Uso Plus foi utilizado seguindo instruções do fabricante, em uma área padronizada de 4mm, seguido da aplicação incremental da resina Z100 (3M). O ensaio de cisalhamento foi realizado em máquina Instron Universal à velocidade de 0,5mm/min. Foi realizada análise estatística pelo teste ANOVA a dois critérios (p < 0,05). Houve diferença significativa entre a resistência adesiva em dentes H e B, sendo os maiores valores para H; houve diferença significativa de resistência para as profundidades analisadas; houve semelhança de comportamento entre os substratos H 0,5mm e B 2mm. O substrato B pode ser empregado em estudos laboratoriais de resistência adesiva como indicativos da performance inicial de novos produtos, observando-se as diferenças existentes entre eles.

Estudo in vivo do manchamento dental causado pela ingestão de café associada ao clareamento profissional / In vivo study of dental discoloration caused by coffee ingestion associated within-office dental bleaching

Objective: The present study aims to verify the effectiveness of in-office dental bleaching using 35% hydrogen peroxide in patients with or without a habit of consuming coffee at least three times per day at different time intervals (pre-bleaching or baseline;48 hours post-bleaching or start; and 90 days post-bleaching or recall). Methods and Material - Forty patients with superior and inferior vital teeth from canine to canine participated in this study. The optical measurements with SpectroShade Microspectrophotometer (MHT, Verona, Italy) determined the pre-bleaching status (baselinemeasurement), the status at 48 hours post-bleaching (start measurement), and thestatus at 90 days post-bleaching (recall measurement). The Delta E (ΔE) value was determined, and the difference between the pre- and post-bleaching luminosity was used as an indicator of the degree of chromogenic alteration. The patients were divided into four groups according to the presence or absence of a coffee ingestion habit and according to different post-bleaching time intervals. These data were analyzed by ANOVA and in case of significant differences the mean values were compared usingthe Tukey test (p < 0.05). Results and Conclusions - In conclusion, it was possible to confirm that professional dental bleaching is an effective technique that can be usedboth in patients who drink and do not drink coffee. However, the maintainability of this treatment was significantly reduced in the group of patients who habitually drink coffee within a period of only 90 days

Objetivos: O presente estudo visa verificar a efetividade do clareamento dental profissional utilizando o peróxido de hidrogênio a 35% em pacientes com e sem o hábito de ingestão de café por pelo menos três vezes ao dia em diferentes intervalosde tempo (pré-clareamento ou baseline; 48 horas pós-clareamento ou start; e 90 diaspós-clareamento ou recall). Material e Métodos - Quarenta pacientes com dentes naturais inferiores e superiores participaram deste estudo. As tomadas de cor com o espectrofotômetro SpectroShade (MHT, Verona, Itália) determinaram a condição pré clareamento(medição baseline), a condição em 48 horas pós-clareamento (medição start),e a condição após 90 dias (medição recall). O valor de Delta E (ΔE) foi determinado, e a diferença entre a luminosidade na condição pré e pós-clareamentos foram utilizadas como o indicador do grau de alteração cromatogênica. Os pacientes foram divididos em quatro grupos de acordo com a presença ou ausência de hábitos de ingestão de café e dos diferentes períodos pós-clareamento. Os dados foram analisados via ANOVA e, quando necessário, os valores médios foram comparados utilizando o teste de Tukeya 5% de significância (p < 0.05). Resultados e Conclusões - Como conclusão foi possível confirmar que clareamento dental profissional é uma técnica efetiva e que pode ser utilizada tanto em pacientes que ingerem como nos que não ingerem café. Contudo, a durabilidade deste tratamento clareador é significativamente reduzida no grupo de pacientes que habitualmente bebem café dentro de um período relativamente curto, ou seja, de apenas 90 dias

Two-year clinical evaluation of self-etching adhesives in posterior restorations.

PURPOSE: To evaluate the 2-year clinical performance of three self-etching adhesives and one etch-and-rinse adhesive (control) in posterior composite restorations. MATERIALS AND METHODS: Upon approval by the Institutional Review Board, 121 restorations were inserted in 38 subjects. The adhesives were applied as per manufacturers' instructions. Preparations were restored with a nanofilled composite resin (Filtek Supreme, 3M ESPE) and evaluated at baseline, 6 months, 1 year, and 2 years. Statistical analyses included the McNemar and the Mann-Whitney non-parametric tests (p < 0.05). RESULTS: At 2 years, 91 out of 121 restorations were evaluated using the USPHS modified criteria. The number of alpha ratings decreased significantly from baseline to 2 years for Adper Prompt L-Pop, Clearfil S3 Bond, and iBond in the categories color match, marginal staining, and marginal adaptation. For One-Step Plus, only marginal staining was significantly worse at 2 years than at baseline. Postoperative sensitivity to air improved significantly for One-Step Plus at 2 years, but this improvement was already detected at 1 year. When the 2-year evaluation criteria were pooled by pairs of adhesives, One-Step Plus resulted in a significantly greater number of alfa ratings for marginal adaptation than the other three adhesives. On the other hand, iBond resulted in a significantly lower number of alfa ratings than any of the other 3 adhesives for color match and marginal staining. Adper Prompt L-Pop, Clearfil S3 Bond, and One-Step Plus resulted in a statistically similar number of alfa ratings for marginal staining and color match. There were no significant differences in any of the evaluation criteria between Clearfil S3 Bond and Adper Prompt L-Pop. CONCLUSION: Only One-Step Plus, the etch-and-rinse adhesive, resulted in good marginal adaptation at 2 years. One of the self-etching adhesives, iBond, resulted in unacceptable clinical performance.

Conhecimento do cirurgião dentista da cidade de São Paulo quanto à prevenção da cárie dental e uso de gomas de mascar / Knowledge of dentists about dental caries prevention and chewing gum in São Paulo city

Os autores desenvolveram uma pesquisa de opinião entre 100 cirurgiões dentistas através da aplicação de um questionário contendo dezesseis perguntas relacionadas com hábitos preventivos. Procurou-se distribuir os questionários de forma a atingir em proporções iguais regiões de variados níveis socioeconômicos na grande São Paulo. Após a tabulação dos dados constatou-se que embora o nível de informação do profissional em alguns aspectos preventivos seja bom, apenas a metade dos grupos pesquisados conhecem os benefícios das gomas de mascar "sugar free" como alternativa aos métodos de higienização convencionais.

One-year clinical performance of self-etch adhesives in posterior restorations.

PURPOSE: To evaluate the 1-year clinical performance of three self-etching adhesives (Adper Prompt L-Pop, Clearfil S3 Bond, iBond) in posterior composite restorations using one etch&rinse adhesive (One-Step Plus) as control. METHODS: Upon approval by the Institutional Review Board, 121 restorations were inserted in 38 subjects. The adhesives were applied as per manufacturers' instructions. Preparations were restored with a nanofilled resin composite (Filtek Supreme) and evaluated at baseline, 6 months, and 1 year. Statistical analyses included the Chi-square distribution with the McNemar non-parametric test (P < 0.05). RESULTS: At 1 year, 111 restorations in 35 subjects were evaluated using the USPHS modified criteria. No significant changes were observed for the etch&rinse adhesive One-Step Plus. At 1 year the number of Alfa ratings decreased significantly for Clearfil S3 Bond and for iBond in the categories color match, marginal staining, and marginal adaptation. For Adper Prompt L-Pop, marginal adaptation at 1 year was significantly worse than at baseline. Postoperative sensitivity to air improved significantly for Adper Prompt L-Pop, Clearfil S3 Bond, and iBond. When the evaluation criteria were paired at 1 year, iBond resulted in a significantly lower number of Alfa ratings than any of the other adhesives for color match, marginal staining, and marginal adaptation. One-Step Plus resulted in a greater number of Alfa ratings for marginal adaptation than either Adper Prompt L-Pop or Clearfil S3 Bond. Marginal adaptation was significantly better for Clearfil S3 Bond than for Adper Prompt L-Pop. The post-operative sensitivity measured at 1 year for Adper Prompt L-Pop was statistically better than that for One-Step Plus.

Clinical performance of a self-etching adhesive at 18 months.

PURPOSE: To test the null hypothesis that beveling and/or etching enamel would not affect the 18-month clinical performance of the self-etching adhesive Clearfil SE Bond (CSEB) in noncarious cervical lesions (NCCL). METHODS: With Institutional Review Board approval, 34 patients were enrolled in this study. A total of 120 NCCL was selected and assigned to four groups: (1) CSEB was applied without any cavity preparation; (2) CSEB was applied after beveling enamel; (3) CSEB was applied after etching enamel for 15 seconds with 35% phosphoric acid; (4) CSEB was applied after beveling and etching enamel. A microfilled composite resin was used for all restorations. RESULTS: At 6 months after initial placement, 120 restorations (a 100% recall rate) were evaluated. At 18 months, 87 restorations (a 72.5% recall rate) were available for evaluation. A survival rate of 100% was measured for all groups at both 6 and 18 months. Sensitivity to air decreased significantly only for Group 3 (no bevel+acid etch) from baseline to 18 months without statistical changes from 6 months to 18 months. None of the other parameters resulted in significant differences for any of the four groups. However, when data were pooled, both the overall marginal discoloration and the overall marginal adaptation were significantly worse at 18 months than at baseline, while sensitivity to air decreased significantly from baseline to 18 months. The 18-month survival rate of the self-etching adhesive Clearfil SE Bond was not improved by enamel bevel or by enamel etching. Both overall marginal adaptation and overall marginal discoloration were worse at 18 months than at baseline. .

The effect of adhesive and flowable composite on postoperative sensitivity: 2-week results.

OBJECTIVE: To measure 2-week postoperative sensitivity in Class II composite restorations placed with a self-etching adhesive (Clearfil SE Bond) or a total-etch adhesive (Prime&Bond NT) with or without a flowable composite as cervical increment. METHOD AND MATERIALS: Upon approval by the University of Guarulhos Committee on Human Subjects, 100 restorations were inserted in 46 patients who required Class II restorations in their molars and premolars. Enamel and dentin walls were conditioned with a self-etching primer (for Clearfil SE Bond) or etched with 34% phosphoric acid (for Prime&Bond NT). A 1- to 2-mm-thick increment of a flowable composite (Filtek Flow) was used in the proximal box in 50% of the restorations of each adhesive. Preparations were restored with a packable composite (Surefil). The restorations were evaluated preoperatively and 2 weeks postoperatively for sensitivity to cold, air, and masticatory forces using a visual analog scale. Marginal integrity of the accessible margins was also evaluated. Statistical analysis used a mixed linear model with subject as a random effect. RESULTS: Ninety-eight teeth from 44 subjects were observed at 2 weeks. The type of adhesive and use of flowable composite had no significant effects or interaction for any of the four outcomes of interest, ie, change from baseline to 2 weeks in sensitivity and response time for the cold or air stimulus. For the air stimulus, the overall average change from baseline was not significant for either sensitivity or response time. For the cold stimulus, the overall average change from baseline was significant for both sensitivity and response time. No case of sensitivity to masticatory forces was observed. CONCLUSION: No differences in postoperative sensitivity were observed between a self-etch adhesive and a total-etch adhesive at 2 weeks. The use of flowable composite did not decrease postoperative sensitivity.

Estudo comparativo entre a distância intercuspídica e a largura de preparos cavitários utilizando pontas diamantadas de diferentes diâmetros / Comparative study between intercuspid distance and width cavities preparation using different dimensions of diamond burs

A abordagem preventiva em relação ao tecido dental e a intensa evolução dos materiais e técnicas adesivas possibilitaram a realização de preparos cavitários mais conservadores. Black, em 1908, propunha como largura cavitária a de 1/3 de distância intercuspídica. Já Markley (1951) preconizava » desta distância. Avanços como a utilização do laser, jatos abrasivos e produtos como Carisolv, modificaram as técnicas de preparos cavitários, porém os preparos convencionais continuam sendo muito utilizados. Este trabalho estudou o diensionamento dos preparos cavitários de classe I oclusais em pré-molares e molares, utilizando diferentes dimensões de pontas diamantadas (1090, 1091 e 1191F). Foram realizadas 200 medições, divididas em 20 grupos, de acordo com os dentes e pontas utilizadas. Mediram-se a distância intercuspídica e os preparos com paquímetro eletrônico digital e os dados foram submetidos a teste estatístico através de análise de variância (Anova) e teste Tukey ao nível de 5 por cento de significância. Os resultados indicaram diferenças estatisticamente significantes entre todos os grupos estudados (p<0,05). Concluiu-se que, atualmente, a distância intercuspídica pode ser muito menor do que a preconizada pela literatura, chegando-se a distâncias de até 1/9 em molares

Influence of acid etching and enamel beveling on the 6-month clinical performance of a self-etch dentin adhesive.

This study tested the hypothesis that beveling and/or etching enamel does not affect the 6-month clinical performance of the self-etch adhesive Clearfil SE Bond in class V noncarious lesions. With Institutional Review Board approval, 34 patients were enrolled in this study. A total of 120 noncarious cervical lesions were selected and assigned to 4 groups: (1) Clearfil SE Bond was applied without any cavity preparation; (2) After the enamel was beveled, Clearfil SE Bond was applied; (3) After the enamel was etched for 15 seconds with 35% phosphoric acid, Clearfil SE Bond was applied; (4) After the enamel was beveled and etched with 35% phosphoric acid for 15 seconds, Clearfil SE Bond was applied. A microfilled composite resin was used for all restorations. Six months after initial placement, 120 restorations (a 100% recall rate) were re-evaluated. Retention rates at 6 months were 100% for all groups. Sensitivity to air improved from baseline to 6 months, but the overall difference was not statistically significant. The 6-month retention rate of the self etch dentin adhesive system Clearfil SE Bond was not improved by enamel beveling or by enamel etching. For the self-etch material Clearfil SE Bond, instrumentation or etching of enamel may not be critical for its clinical performance at 6 months.

Finite elements study of the Flexi Post and Flexi Flange post systems in a maxillary central incisor.

The use of post and core systems has become an excellent alternative for restoring endodontically treated teeth. The aim of this study was to evaluate the von Mises, maximal compressive and tensile stresses distribution using the Finite Element Method (FEM) on human teeth restored with different post and core systems. The analysis was made on endodontically treated maxillary central incisors. The post systems used in this investigation were the stainless steel or titanium Flexi Post/Flexi Flange. Composite resin was used as core material and resin cement was the cement material of choice to seat a full porcelain crown. The bi-dimensional mathematical model was created from pictures taken from an intact human maxillary central incisor and prefabricated posts. This image was transferred to a personal computer in the MSC/Nastran 4.5 software. A static and linear analysis treatment was performed when a 45 load of 100 N was applied on the lingual surface of the tooth. Based on the results obtained, it can be concluded that the post design and its material can alter the stress pattern distribution.

Polymerization shrinkage evaluation of three packable composite resins using a gas pycnometer

Modern restorative dentistry has been playing an outstanding role lately since composite resins, allied to adhesive systems, have been widely applied on anterior and posterior teeth restorations. The evolution of composite resins has mostly been verified due to the improvement of their aesthetic behavior and the increase in their compressive and abrasive strengths. In spite of these developments, the polymerization shrinkage inherent to the material has been a major deficiency that, so far, has been impossible to avoid. Using a gas pycnometry, this research investigated the polymerization shrinkage of three packable composite resins: Filtek P60 (3M), Prodigy Condensable (Kerr), and SureFil (Dentsply/Caulk), varying the distance from the light source to the surface of the resins (2 mm or 10 mm). The pycnometer Accupyc 1330 (Micromeritics, USA) precisely records helium displacement, allowing fast and reliable measurements of the volume of composite resin immediately before and after polymerization, without interference of temperature or humidity. Results were not found to be statistically different for the three tested resins, either for 2 mm or 10 mm-distance from the light source to the composite surface

Facetas indiretas em porcelana - alternativa estética / Porcelain laminate veneers - aesthetic alternative

Com o advento de novos materiais restauradores estéticos, surgiram alternativas inovadoras de tratamento para dentes anteriores. A faceta laminada de porcelana é uma modalidade de tratamento odontológico que, na maioria dos casos, requer desgaste mínimo da estrutura dentária remanescente e está indicada em casos de alterações de estrutura, cor, forma ou posição dentária. A porcelana oferece às restaurações maior estética e resistência à abrasão quando comparada à resina composta, além de possuir estabilidade de cor e biocompatibilidade com os tecidos gengivais. A confecção das facetas em porcelana constitui uma técnica confiável, com baixa taxa de insucesso, cujo resultado proporciona uma sensação de bem-estar, eleva a auto-estima e favorece as relações socias e profissionais dos pacientes. Se os passos clínicos e laboratoriais forem conduzidos com cautela e eficiência durante os procedimentos de preparo, moldagem, prova, cimentação e ajuste da faceta, sem que se esqueça da importância da indicação precisa do caso, o resultado será bastante favorável, garantindo longevidade ao trabalho e satisfação ao paciente

Finite elements study of the Flexi Post and Flexi Flange post systems in a maxillary central incisor

The use of post and core systems has become an excellent alternative for restoring endodontically treated teeth. The aim of this study was to evaluate the von Mises, maximal compressive and tensile stresses distribution using the Finite Element Method (FEM) on human teeth restored with different post and core systems. The analysis was made on endodontically treated maxillary central incisors. The post systems used in this investigation were the stainless steel or titanium Flexi Post/Flexi Flange. Composite resin was used as core material and resin cement was the cement material of choice to seat a full porcelain crown. The bi-dimensional mathematical model was created from pictures taken from an intact human maxillary central incisor and prefabricated posts. This image was transferred to a personal computer in the MSC/Nastran 4.5 software. A static and linear analysis treatment was performed when a 45º load of 100 N was applied on the lingual surface of the tooth. Based on the results obtained, it can be concluded that the post design and its material can alter the stress pattern distribution

Cimentos de ionômero de vidro: 1969 a 2002 / Glass ionomer cements: from 1969 to 2002

Os cimentos de ionômero de vidro ocupam hoje um papel de destaque na Odontologia moderna e oferecem consideráveis vantagens em certas áreas em relação a outros materiais, principalmente para lesões cervicais por abrasão, erosão ou cárie. Estas vantagens resultam das suas propriedades de liberação de íons fluoreto, estabilidade dimensional e adesão ao esmalte e à dentina. O propósito deste estudo foi revisar a literatura, destacando sua natureza e evolução, indicações e as limitações que o envolvem, desde o lançamento do primeiro produto comercial, até os modernos cimentos de ionômero de vidro modificados por resina