Effect of aging and cementation systems on the bond strength to root dentin after fiber post cementation.

This study evaluated the effect of aging and cementation of fiber posts using glass ionomer and resin cements on push-out bond strength, failure mode, and resin tag formation. One hundred and twenty bovine incisors were used. After post-space preparation, the specimens were randomly allocated into 12 groups (n = 10) according to the cementation system used: GC - GC Gold Label Luting & Lining); RL - RelyX Luting 2; MC - MaxCem Elite; RU - RelyX U200 and the aging periods (24 hours, 6 months, and 12 months). Slices from the cervical, middle, and apical thirds were obtained and analyzed by push-out bond strength test and confocal laser scanning microscopy. One-way ANOVA and Tukey's post-hoc test was used at a significance level of 5%. For the push-out bond strength test, no differences among GC, RU, and MC in the cervical and middle thirds were observed, regardless of the period of storage (P > 0.05). In the apical third, GC and RU showed similar bond strength but higher than other groups (P > 0.05). After 12 months, GC showed the highest bond strength (P < 0.05). Bond strength to post-space dentin decreased over time, regardless of the cementation system used. Cohesive failure was the most frequent, regardless of the period of storage, cementation system, and post-space third. Tag formation was similar among all groups. After 12 months, GC showed the highest bond strength values.

Effect of aging and cementation systems on the bond strength to root dentin after fiber post cementation

Abstract This study evaluated the effect of aging and cementation of fiber posts using glass ionomer and resin cements on push-out bond strength, failure mode, and resin tag formation. One hundred and twenty bovine incisors were used. After post-space preparation, the specimens were randomly allocated into 12 groups (n = 10) according to the cementation system used: GC - GC Gold Label Luting & Lining); RL - RelyX Luting 2; MC - MaxCem Elite; RU - RelyX U200 and the aging periods (24 hours, 6 months, and 12 months). Slices from the cervical, middle, and apical thirds were obtained and analyzed by push-out bond strength test and confocal laser scanning microscopy. One-way ANOVA and Tukey's post-hoc test was used at a significance level of 5%. For the push-out bond strength test, no differences among GC, RU, and MC in the cervical and middle thirds were observed, regardless of the period of storage (P > 0.05). In the apical third, GC and RU showed similar bond strength but higher than other groups (P > 0.05). After 12 months, GC showed the highest bond strength (P < 0.05). Bond strength to post-space dentin decreased over time, regardless of the cementation system used. Cohesive failure was the most frequent, regardless of the period of storage, cementation system, and post-space third. Tag formation was similar among all groups. After 12 months, GC showed the highest bond strength values.

Resumo Avaliar o efeito do envelhecimento e sistemas de cimentação usando ionômero de vidro e cimentos resinosos na resistência de união à dentina após a cimentação do pino de fibra. Cento e vinte incisivos bovinos foram utilizados. Após o preparo do pós-espaço, os corpos de prova foram distribuídos aleatoriamente em 12 grupos (n = 10) de acordo com o período de envelhecimento (24 horas, 6 meses e 12 meses) e o sistema de cimentação utilizado: GC - cimento de ionômero de vidro (GC Gold Label Cimentação e Revestimento); RL - RelyX Luting 2; MC - MaxCem Elite; RU - RelyX U200. Cortes dos terços cervical, médio e apical foram obtidos e analisados por teste de resistência de união push-out e microscopia confocal de varredura a laser. ANOVA one-way e teste de Tukey foi usado a um nível de significância de 5%. Para o teste de resistência de união, não foram observadas diferenças entre GC, RU e MC nos terços cervical e médio, independentemente do período de armazenamento (P > 0,05). No terço apical, GC e RU apresentaram resistência de união semelhante, porém superior aos demais grupos (P > 0,05). Após 12 meses, o GC apresentou a maior resistência de união (P < 0,05). A resistência de união à dentina no espaço para pino diminuiu ao longo do tempo, independentemente do sistema de cimentação utilizado. A formação de tags foi semelhante entre todos os grupos. Após 12 meses, o GC apresentou os maiores valores de resistência de união.

Management of Tooth Discoloration after Orthognathic Surgery Complications: Report of Two Cases

ABSTRACT: Orthognathic surgery is performed for the correction of craniofacial discrepancies. However, complications, such as tooth discoloration are possible. This case report presents two patients who underwent bilateral sagittal split ramus osteotomy associated with segmental Le Fort I osteotomy and genioplasty. During surgeries, the apical region of anterior teeth was accidentally injured in both cases. After three-week surgery follow-up, the injured teeth showed a change in color to dark pink. In both teeth, the root canal treatment was performed followed by the non vital tooth bleaching. Three sessions were necessary to achieve a significant color change of the teeth. The two-year follow-up showed that both teeth preserved an acceptable color. It was concluded that tooth discoloration after orthognathic surgery is a possible complication, which could be overcome following a conservative approach. Additionally, patients should be informed preoperatively.

RESUMEN: La cirugía ortognática es comúnmente realizada para corregir las discrepancias cráneo-faciales. Sin embargo, se pueden producir complicaciones tales como la pigmentación dentaria. Este reporte de casos presenta a dos pacientes que fueron sometidos osteotomía sagital bilateral de la rama mandibular asociada a osteotomía segmentaria Le Fort I y genioplastía. Durante la fase quirúrgica, la región apical de dientes anteriores fueron accidentalmente dañados en ambos casos. Después de tres semanas de seguimiento de la cirugía, los dientes afectados mostraron un cambio de color a rosado oscuro. Se realizó el tratamiento de conductos seguido de aclaramiento interno en ambas piezas dentarias. Fueron necesarias tres sesiones para lograr un cambio de color significativo. El seguimiento de dos años mostró que ambos dientess conservaron un color aceptable. En conclusión, la pigmentación dentaria después de la cirugía ortognática es una posible complicación, sin embargo, puede ser tratada por medio de un enfoque conservador. Además, los pacientes deben ser informados antes de la cirugía.

Influência de tratamento dentinário com EDTA sobre a resistência de união de sistemas adesivos autocondicionantes / Effectiveness of EDTA in restorative procedures with self-etching adhesives

Resumo Introdução Os adesivos autocondicionantes apresentam técnica adesiva simplificada e diminuição na sensibilidade pós-operatória. Quando aplicados sobre a dentina, atuam sobre a smear layer, cuja efetiva remoção ainda constitui um desafio. Uma substância utilizada como pré-tratamento dentinário na ajuda da remoção da smear layer é o etilenodiamino tetracético dissódico (EDTA). Objetivo Avaliar os efeitos do EDTA em associação com sistemas adesivos autocondicionantes na resistência de união ao microcisalhamento. Material e método Foram seccionadas as superfícies oclusais de 72 terceiros molares humanos extraídos, para expor superfície dentinária plana. Os dentes preparados foram divididos em: dentina sem pré-tratamento; dentina tratada com EDTA 0,1M; dentina tratada com EDTA 0,5M. Cada grupo recebeu tratamento de três sistemas adesivos autocondicionantes: Single Bond Universal (SBU), AdheSE (AdheSE) e Clearfil SE Bond (CSEB). Foi delimitada a área adesiva e assim posicionada uma matriz transparente, para inserção com resina composta Z250XT seguida de polimerização por 40 segundos. Após 24 horas de armazenamento, os dentes foram submetidos ao ensaio de microcisalhamento. Os dados obtidos foram analisados estatisticamente, utilizando-se os testes Two-Way ANOVA e Bonferroni, e sendo considerado nível de significância de 5%. Resultado Não houve diferença estatística significante na resistência de união entre os pré-tratamentos dentinários (p=0,8353), porém houve diferença significativa entre os adesivos (p<0,05) CSEB e AdheSE, mostrando semelhança entre CSEB e SBU, e entre SBU e AdheSE. Conclusão O pré-tratamento dentinário com solução de EDTA não afetou a resistência de união com nenhum dos sistemas adesivos autocondicionantes utilizados.

Abstract Introduction Self-etching adhesives have simplified adhesive technique and decreased the postoperative sensitivity. When applied on dentin, it acts on the smear layer, but it is still a challenge in the effectiveness of this removal. A substance used as a pre-treatment for the removal of the smear layer is disodium ethylenediaminetetraacetic acid (EDTA). Objective To evaluate the effects of EDTA in association with self-etching adhesive systems on micro-shear bond strength. Material and method The occlusal surfaces of 72 extracted human third molars were sectioned to expose a flat dentin surface. The prepared teeth were divided into: dentin without pre-treatment; dentin treated with 0.1M EDTA; dentin treated with 0.5M EDTA. Each group received treatment of 3 self-etching adhesive systems: Single Bond Universal (SBU), AdheSE (AdheSE), and Clearfil SE Bond (CSEB). The adhesive area was delimited and positioned a transparent matrix for insertion with Z250XT composite resin followed by polymerization for 40 seconds. After 24h of storage, the teeth were submitted to the micro-shear test. The data were analyzed statistically using the Two-Way ANOVA and Bonferroni tests, considering a level of significance of 5%. Result There was no statistically significant difference in bond strength between dentin pre-treatments (p = 0.8353), but showed a significant difference between CSEB and AdheSE adhesives (p <0.05), showing similarity between CSEB and SBU, and between SBU and AdheSE. Conclusion Dentin pretreatment with EDTA solution did not affect bond strength with any of the self-etching adhesive systems used.

Personality Style in Patients Looking for Tooth Bleaching and Its Correlation with Treatment Satisfaction.

In the last years the focus in dentistry has shifted to an "esthetic dentistry" approach, where patients are concerned about reaching a better look of their teeth. Vital tooth bleaching is a technique with immediate results, which improves the appearance and patient's self-esteem. The aim of this study was to recognize personality characteristics determined by the Millon Index of Personality Styles of participants looking for tooth bleaching and to correlate them to satisfaction with the treatment. Forty participants were included and filled out the Millon Index of Personality Styles form before treatment. Expectation about tooth bleaching was quantified from 1 to 5. Patients were treated with bleaching agent according to manufacturer's directions. One week after treatment, the patient's satisfaction was quantified from 1 to 5. Prevailing personality characteristics were determined. Expectations and satisfaction values of all patients were correlated with each of the presented personality scales by Spearman Rho test. Ten scales prevailed over their counterpart. Median of patient's expectation was 2 and satisfaction 4. Only the score of a single characteristic (extraversing) showed statistically significant correlation with patient satisfaction. Patients looking for tooth bleaching treatment seem to have common personality characteristics. Almost all of them wanted to achieve a moderate change in teeth color and the result of the treatment was usually satisfactory.

Personality Style in Patients Looking for Tooth Bleaching and Its Correlation with Treatment Satisfaction

Abstract In the last years the focus in dentistry has shifted to an "esthetic dentistry" approach, where patients are concerned about reaching a better look of their teeth. Vital tooth bleaching is a technique with immediate results, which improves the appearance and patient's self-esteem. The aim of this study was to recognize personality characteristics determined by the Millon Index of Personality Styles of participants looking for tooth bleaching and to correlate them to satisfaction with the treatment. Forty participants were included and filled out the Millon Index of Personality Styles form before treatment. Expectation about tooth bleaching was quantified from 1 to 5. Patients were treated with bleaching agent according to manufacturer's directions. One week after treatment, the patient's satisfaction was quantified from 1 to 5. Prevailing personality characteristics were determined. Expectations and satisfaction values of all patients were correlated with each of the presented personality scales by Spearman Rho test. Ten scales prevailed over their counterpart. Median of patient's expectation was 2 and satisfaction 4. Only the score of a single characteristic (extraversing) showed statistically significant correlation with patient satisfaction. Patients looking for tooth bleaching treatment seem to have common personality characteristics. Almost all of them wanted to achieve a moderate change in teeth color and the result of the treatment was usually satisfactory.

Resumo Ultimamente, o foco da Odontologia deslocou-se para uma "odontologia estética", em que os pacientes se preocupam em conseguir uma aparência melhor para seus dentes. O branqueamento vital é uma técnica com resultados imediatos que melhora aparência e auto-estima do paciente. O objetivo deste estudo foi detectar características de personalidade definidas pelo Índice Millon de Estilos de Personalidade de pessoas que buscaram branqueamento dental e correlacioná-las com a satisfação com o tratamento. Foram incluídos 40 participantes que preencheram o formulário do Índice Millon de Estilos de Personalidade antes do tratamento. A expectative sobre o branqueamento dental foi quantificada com valores de 1 a 5. Os pacientes foram tratados com agente branqueador de acordo com as instruções do fabricante. Uma semana depois o tratamento, a satisfação do paciente foi quantificada com valores de 1 a 5. Foram determinados as características predominantes. Os valores da expectativa e da satisfação foram correlacionados com cada escala de personalidade apresentada através do teste de Spearman Rho. Dez escalas prevaleceram sobre a sua contrapartida. A mediana das expectativas foi 2 e das satisfações foi 4. O valor de uma característica apenas (extraversão) apresentou correlação estatisticamente significante com a satisfação do paciente. Os pacientes que buscam o branqueamento dental parecem ter características comuns de personalidade. Quase todos queriam conseguir uma mudança moderada na cor dos dentes e o resultado do tratamento foi geralmente satisfatório.

Gastroprotective effects and antimicrobial activity of Lithraea molleoides and isolated compounds against Helicobacter pylori.

ETHNOPHARMACOLOGICAL RELEVANCE: Lithraea molleoides (Vell.) Engl. (Anacardiaceae) is a medicinal plant traditionally used in South America to treat various ailments, including diseases of the digestive system. AIM OF THE STUDY: To evaluate the in vivo antiulcer and antimicrobial activities against Helicobacter pylori of L. molleoides and its isolated compounds. MATERIALS AND METHODS: Methanolic extract 250 and 500 mg/kg, (LmE 250 and LmE 500, respectively) and infusions, 10 g and 20 g en 100mL (LmI 10 and LmI 20, respectively) of L. molleoides was evaluated for antiulcer activity against 0.6N HCl, 0.2N NaOH, 200mg/kg acetilsalicilic acid and absolute ethanol-induced gastric ulcers in rats. The degree of erosion in the glandular part of the stomach was assessed from a scoring system. Acute toxicity in mice was also evaluated. The antiulcer effect of the isolated compounds (catechol, mannitol, rutin, gallic acid, ferulic acid and caffeic acid, 100mg/kg) was evaluated against absolute ethanol-induced gastric ulcers in rats. The anti-Helicobacter pylori activity of L. molleoides and isolated compounds was performed using broth dilution methods. RESULTS: The LmE 250, LmE 500, LmI 10 and LmI 20 produced significant inhibition on the ulcer index in 0.6N HCl, 0.2N NaOH, 200mg/kg acetilsalicilic acid and absolute ethanol- induced gastric ulcers in rats. The isolated compounds, catechol, mannitol, rutin, ferulic acid and caffeic acid were active in absolute ethanol- induced gastric ulcers in rats. L. molleoides and different compounds showed antimicrobial activity in all strains tested. The lowest MIC value (0. 5 µg/mL) was obtained with catechol in six of eleven strains assayed. No signs of toxicity were observed with doses up to 2g/kg in an acute toxicity assay. CONCLUSION: These findings indicate that L. molleoides displays potential antiulcerogenic and antimicrobial activities and the identification of active principles could support the use of this plant for the treatment of digestive affections.

Ultrasound Effect in the Removal of Intraradicular Posts Cemented with Different Materials.

AIM: This study evaluated the effect of ultrasonic vibration on the tensile strength required to remove intraradicular post cemented with different materials. MATERIALS AND METHODS: Bovine teeth were selected, and 7 mm of the cervical root canals were prepared to size 5 Largo drill, the posts were cemented with zinc phosphate, Enforce (resin) or Rely X (glass ionomer). The specimens were divided into six groups (n = 10), according to the following procedures: GI-cementation with zinc phosphate associated with traction force; GII-cementation with zinc phosphate associated with ultrasonic activation and traction force; G111-cementation with Enforce associated with traction force; GIV-cementation with Enforce associated with ultrasonic activation and traction force; GV-cementation with Rely X associated with traction force; and GVI-cementation with Rely X associated with ultrasonic activation and traction force. The tensile test was conducted using the electromechanical testing machine, the force was determined by a specialized computer program and ultrasonic activation using the Jet Sonic Four Plus (Gnatus) device in 10P. RESULTS: Concerning to average ranking, GI showed statistically significant difference in comparison with GII and GVI (p < 0.05); there was no statistical difference in GIII and GIV when compared to other groups (p > 0.05). CONCLUSION: The ultrasound favored the intraradicular post traction regardless of the employed cement in greater or lesser extent. CLINICAL SIGNIFICANCE: The post removal is a routine practice in the dental office, therefore, new solutions and better alternatives are need to the practitioner. We did not find in the literature many articles referring to this practice. Thus, the results from this study are relevant in the case planning and to promote more treatment options.

Is there difference of Streptococcus mutans count and adherence on amalgam and resin occlusal restorations? A blind clinical study

To compare the number of colony forming units CFU and agar adherence of S. mutans on amalgam AM and resin composite RC occlusal restorations. Sixty-five healthy patients older than 18 years with high caries risk who had at least one occlusal AM and RC restorations n=130 were selected. METHODS: The restorations were evaluated according to the alpha Ryge criteria Cohen-Kappa 0.8. For each patient, a biofilm sample was taken using an impression tray technique with previously loaded with solid trypticase yeast extract cysteine sucrose with bacitracin agar placed over the AM restorations and RC restorations in the same patients. The tray was placed inside an oven at 37 °C for 48 h, and the S. mutans count was then performed. Data were analyzed with the test Wilcoxon with a 95% confidence level. RESULTS: RC restorations had statistically significant higher number of CFU of S. mutans than AM restorations p<0.05. CONCLUSIONS: In adult patients with high caries risk, RC occlusal surfaces showed greater agar adherence of S. mutans count than AM restorations...

Comparación de la fuerza adhesiva de 2 sistemas de cementos de resina en diferentes regiones radiculares en la cementación de postes de fibra / Comparison of bond strength of two resin cement systems in different roots region on the cementation of fiber posts

La causa de fracaso más común de los postes de fibra es su desalojo, principalmente debido a la compleja adhesión dentro del conducto radicular. El principal objetivo de este estudio fue determinar si existe diferencia significativa en la resistencia adhesiva mediante el test push-out en la cementación de postes de fibra con RelyX U-200® (U200) y Core Paste XP® (CPX) en diferentes regiones radiculares. MATERIALES Y MÉTODOS Se seleccionaron 40 premolares, se seccionaron a 15 mm del ápice, fueron tratados endodóncicamente y fueron divididos aleatoriamente en 2 grupos de 20, a los cuales se les cementó un poste de fibra translúcido Exacto® con U200 y CPX. Después de 24 h cada muestra fue seccionada transversalmente a nivel cervical, medio y apical. Fueron sometidas al test de push-out mediante la máquina Tinius Olsen HK5-S para cuantificar la resistencia adhesiva en megapascales. Se utilizó el test Shapiro-Wilk, test de ANOVA de 2 factores y Tukey con un nivel de significación del 95%. RESULTADOS No hubo diferencia significativa de ambos cementos (p = 0,457), pero sí hubo diferencia cuando se comparó el tipo de cemento y la región; CPX presentó valor significativamente mayor en el tercio cervical (p < 0,05), mientras que U200 presentó un valor significativamente mayor en el tercio apical (p < 0,05). CONCLUSIONES No hubo diferencia significativa en el valor de adhesión cuando se comparó solo el factor cemento entre U200 y CXP, sin embargo hubo un mayor valor de CXP a nivel cervical y de U200 a nivel apical.

Loosening is the most common failure of fiber posts, mainly due to complex adhesion within the root canal. The main objective of this study was to determine if significant differences in adhesive resistance, using the push-out test, in the cementation of fiber posts with RelyX U-200® (U200) and Core Paste XP® (CPX) in different root regions. MATERIALS AND METHODS A selection of 40 premolars were sectioned 15 mm from the apex, treated endodontically and then randomly divided in two groups of 20, using an Exacto translucent fiber post with U200 and CPX, respectively. After 24 hours, each sample was sectioned into cervical, middle and apical. The test push-out test was performed using a Tinius Olsen HK5-S machine to quantify the adhesive strength in Mega Pascals. The test Shapiro-Wilk, two-factor Anova and Tukey tests were used with a significance level of 95% RESULTS There were no significant differences between the cements (P = .457) but if there was difference when comparing the type of cement and region. CPX showed a value significantly higher in the cervical third (P < .05), while U200 presented a value significantly higher in the apical third (P < .05). CONCLUSIONS There was no significant difference in the value of the adhesive strength in the comparison between U200 and CXP, however there was a higher value of CXP at cervical and U200 at apical level.

Human dental enamel and dentin structural effects after Er:YAG laser irradiation.

UNLABELLED: Ideally projected to be applied on soft tissues, infrared lasers were improved by restorative dentistry to be used in hard dental tissues cavity preparations--namely enamel and dentin. This paper evidentiates the relevant aspects of infrared Erbium laser's action mechanism and its effects, and characterizes the different effects deriving from the laser's beams emission. The criteria for use and selection of optimal parameters for the correct application of laser systems and influence of supporting factors on the process, such as water amount and its presence in the ablation process, protection exerted by the plasma shielding and structural factors, which are indispensable in dental tissues cavity preparation related to restorative technique, are subordinated to optical modifications caused by the interaction of the energy dissipated by these laser light emission systems in the targeted tissue substrate. CLINICAL RELEVANCE: Differences in the action of infrared Erbium laser system in regard to the nature of the ablation process and variations on the morphological aspects observed in the superficial structure of the target tissue irradiated, may be correlated to the structural optical modifications of the substrate produced by an interaction of the energy propagated by laser systems.

Marginal adaptation of class V restorations with current-generation dentin-bonding agents: effect of different dentin surface treatments.

This study sought to assess the use of chlorhexidine with several excipients as a dentin surface treatment and its effect on marginal adaptation of class V restorations with current-generation dentin bonding agents. A total of 120 human third molars were selected and allocated into 12 groups, with standardized buccal class V restorations randomly divided into preconditioned dentin rinsed with: water; water + chlorhexidine; ethanol; or ethanol + chlorhexidine. After rinsing of dentin (previously conditioned with 35% phosphoric acid) with the test solutions, the Adper single bond 2, prime and bond 2.1, and Excite bonding systems were applied randomly. Restorations were performed with Filtek™ Z350 XT composite resin. The resulting specimens were subjected to thermal and mechanical load cycling. Quantitative analysis of marginal adaptation was performed on epoxy replicas by means of scanning electron microscopy. Results were assessed by means of the Kruskal-Wallis test (percentages of continuous margins) and Wilcoxon test (differences between percentages of continuous margins before and after thermal cycling and mechanical loading), at a significance level of p < 0.05. Outcomes in the chlorhexidine-treated groups were not superior to those obtained with other treatments.

Effect of different light-curing techniques on hardness of a microhybrid dental composite resin / Efeito de diferentes técnicas de fotoativação na dureza de uma resina composta dental microhíbrida

Objective: This study assessed the Vickers hardness (VHN) provided by two LCUs when using (1) direct and indirect light-curing techniques, (2) 40 and 60 s and (3) top and bottom surfaces. Material & Methods: One halogen Curing Light 2500 (3M Espe) and one LED (MM Optics) were used by direct and indirect (0,1.0, 2.0 and 3.0 mm of dental structure) techniques during 40 and 60 s. The samples were made with FiltekTM Z250 in a metallic mould with a central orifice (4 mm in diameter, 2 mm in thickness). The samples were stored in dry mean by ± 24 h and the hardness measurements were performed in a testing machine (Buehler MMT-3 digital microhardness tester Lake Bluff, Illinois USA). A 50 gf load was used and the indenter with a dwell time of 30 s. The data were submitted to multiple ANOVA and Newman-Keuls‘s test (p < 0.05). Results: Halogen LCU exhibited higher Vickers hardness values than LED mainly because of the power density used. Hardness values were influenced by LCUs, lightcuring techniques, irradiation times and surfaces. For both LCUs, hardness values were found to decrease with indirect light-curing technique, mainly for the bottom surface. Samples irradiated for 60 s exhibited higher hardness values when the halogen LCU was used. For 60 s, the VHN values were statistically significant greater than 40 s. Significant differences in top and bottom surfaces Vickers hardness number (VHN) values were observed among different LCUs used 40 and 60 s. Conclusion: The LCUs, lightcuring techniques, variations of irradiation times, and surfaces (top and bottom) influence the composite resin hardness.

Objetivo: Este estudo avaliou a dureza Vickers (VHN) em função de duas fontes de luz quando utilizadas diferentes (1) técnicas de fotoativação, direta e indireta, (2) 40 e 60 s, e (3) superfícies de topo e base. Material e Métodos: Uma fonte de luz halógena Curing Light 2500 (3M Espe) e um LED (MM Optics) foram utilizados nas técnicas de fotoativação direta e indireta (0 , 1,0, 2,0 e 3,0 milímetros de estrutura dental), durante 40 e 60 s. As amostras foram feitas utilizando-se FiltekTM Z250 em matriz metálica com orifício central (4 mm de diâmetro, com 2 mm de espessura). As amostras foram armazenadas em meio seco por ± 24 h e as medidas de dureza foram realizadas em microdurômetro (Buehler MMT-3 digital microhardness tester Lake Bluff, Illinois USA). Uma carga de 50 gf durante 30 s foi utilizada. Os dados foram submetidos à análise de variância múltipla e teste de Newman-Keuls (p < 0,05). Resultados: A fonte de luz halógena promoveu os maiores valores de dureza Vickers, principalmente, em função da densidade de potência utilizada. Os valores de dureza foram influenciados pelas fontes de luz, técnicas de fotoativação, tempos de irradiação e superfícies, topo e base. Para ambas as fontes de luz, os valores de dureza diminuíram com a técnica de fotoativação indireta, principalmente para a superfície de base. Amostras irradiadas por 60 s apresentaram valores de dureza maiores quando a fonte de luz halógena foi utilizada. Durante 60 s , os valores de VHN foram estatisticamente significativos maior do que 40 s. Diferenças significativas foram observadas nos valores dureza Vickers (VHN) para as superfícies de topo e base utilizando 40 e 60 s. Conclusão: As fontes de luz, técnicas de fotoativação direta e indireta, tempos de irradiação e superfícies (topo e base) influenciam na dureza da resina composta.

Application of the finite element method in Dentistry

Introduction: The finite element method (FEM) involves a series of computational procedures to calculate the stress in each element, which performs a model solution. Such a structural analysis allows the determination of stress resulting from external force, pressure, thermal change, and other factors. This method is extremely useful for indicating mechanical aspects of biomaterials and human tissues that can hardly be measured in vivo. The results obtained can then be studied using visualization software within the FEM environment to view a variety of parameters, and to fully identify implications of the analysis. Objective: An overview to show application of FEM in dentistry was undertaken. Literature review: This paper shows the basic concept, advances, advantages, limitations and applications of finite element method (FEM) in dentistry. Conclusion: It is extremely important to verify what the purpose of the study is in order to correctly apply FEM.

Degree of conversion of polymer-matrix composite assessed by FTIR analysis.

AIMS AND OBJECTIVES: The behavior of polymer-matrix composite is dependent on the degree of conversion. The aim of this study was to evaluate the degree of conversion of two resin cements following storage at 37°C immediately, 24 and 48 hours, and 7 days after light-curing by FTIR analysis. MATERIALS AND METHODS: The specimens were made in a metallic mold and cured with blue LED with power density of 500 mW/ cm(2) for 30 seconds. The specimens were pulverized, pressed with KBr and analyzed with FTIR following storage times. STATISTICAL ANALYSIS USED: ANOVA (two-way) and Tukey's post hoc. RESULTS: To the polymer-matrix composites between 24 and 48 hours does not show a significant increase (p > 0.05), however, the highest values were found after 7 days. CONCLUSION: The polymer-matrix composites used in this study showed similarity on the degree of conversion and increased of according to the time of storage.

ScanWhite: método objetivo para avaliação do nível de clareamento dentário / ScanWhite: Objective method for dental bleaching level evaluation

Introdução: o clareamento dentários pode ser avaliado por meio de técnicas comparativas subjetivas (visual) ou objetivas (instrumental). Essa última tem se mostrado mais adequado para tal tipo de avaliação. Métodos: a avaliação do sistema foi realizado em laboratório, utilizando-se uma câmara digital, escala de cores Vita Classical e tres diferentes tipos de iluminação. No total, foram realizadas 480 imagens. Em seguida, o software foi avaliado quanto à sua eficiência clínica. Para tal, foi selecionado um caso de microabrasão complementado com clareamento dentário fotoacelerado. Resultados: os testes laboratoriais com diferentes iluminantes apresentaram resultados similares. Clinicamente, foram obsaervados diferentes níveis de clareamento em cada uma das sessões clínicas realizadas. Discussão: os vários métodos objetivos disponíveis atualmente apresentam diferentes graus de imitação na análise da cor de corpos semitranslúcidos (por exemplo, dentes e materiais dentários). Essas estão relacionadas ao posicionamento e ao sistema de cor utilizado (por exemplo, RGB, CYM) por cada equipamento. Portanto, o método proposto apresenta algumas vantagens em relação aos sistemas objetivos, como a ausência da necessidade de manutenção do posicionamento da amostra ou do paciente, algoritmo calibrador e a geração de gráficos e laudos. Conclusões: as comprovações geradas pelo sistema proposto geram maior conforto e segurança durante o tratamento

Introduction: The dental bleaching outcome can be evaluated using subjective (visual) and objective (instrumental) comparative techniques. The latter has demonstrated more suitable results to that kind of evaluation. Methods: The assessment of the proposed system was realized in th laboratory using Vita Classical color pallets, digital camera and three different illuminations. In total, 480 images were acquired. Next, the software was evaluated to check its clinical efficiency.For this, a case of micro-abrasion complemented with photoacelerated dental bleaching was chosen. Results: The laboratorial tests with different illuminants showed similar results. Clinically different levels of dental bleaching were observed in each one of the clinical appointments realized. Discussion: The several objective methods available nowadays present different limitation levels when analysing semitranslucid samples (e.g. teeth and dental materials). These limitations are related with the samples's position and with the color space used by each system (e.g. RGB, CYM). Therefore, the proposed method shows some advantages when compared with the traditional objective methods, such as the absence of position maintenance of the sample or of the patient, calibration algorithm and generation of graphs and reports. Conclusions: The outcomes generated by the proposed system can provide more security both to patient and professional during the treatment

Using the self-etch adhesives in anterior restoration.

With the arrival of self-etch adhesives systems, there has been a rise in interest among clinicians, making it imperative for health professionals to have knowledge of the properties, characteristics, the association as well as the dental structures of these materials, in order to select them and use them correctly. The self-etch adhesive systems show good values of bond strength, microleakage and performance, and have therefore become an option in direct adhesive restorations. In the regard, this case study aims to describe the technique involving the use of selfetch adhesives system for direct restoration of anterior teeth.

Degree of conversion of nanofilled and microhybrid composite resins photo-activated by different generations of LEDs.

OBJECTIVE: This study aimed at evaluating the degree of conversion (DC) of four composite resins, being one nanofilled and 3 microhybrid resins, photo-activated with second- and third-generation light-emitting diodes (LEDs). MATERIAL AND METHODS: Filtek™ Z350 nanofilled composite resins and Amelogen® Plus, Vit-l-escence™ and Opallis microhybrid resins were photo-activated with two second-generation LEDs (Radii-cal and Elipar Free Light™ 2) and one third-generation LED (Ultra-Lume LED 5) by continuous light mode, and a quartz halogen-tungsten bulb (QHT, control). After 24 h of storage, the samples were pulverized into fine powder and 5 mg of each material were mixed with 100 mg of potassium bromide (KBr). After homogenization, they were pressed, which resulted in a pellet that was evaluated using an infrared spectromer (Nexus 470, Thermo Nicolet) equipped with TGS detector using diffuse reflectance (32 scans, resolution of 4 cm(-1)) coupled to a computer. The percentage of unreacted carbon-carbon double bonds (% C=C) was determined from the ratio of absorbance intensities of aliphatic C=C (peak at 1637 cm-1) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm-1). RESULTS: The ANOVA showed a significant effect on the interaction between the light-curing units (LCUs) and the composite resins (p<0.001). The Tukey’s test showed that the nanofilled resin (Filtek™ Z350) and Opallis when photo-activated by the halogen lamp (QTH) had the lowest DC compared with the other microhybrid composite resins. The DC of the nanofilled resin (Filtek™ Z350) was also lower using LEDs. The highest degrees of conversion were obtained using the third-generation LED and one of second-generation LEDs (Elipar Free Light™ 2). CONCLUSIONS: The nanofilled resin showed the lowest DC, and the Vit-l-escence™ microhybrid composite resin showed the highest DC. Among the LCUs, it was not possible to establish an order, even though the second-generation LED Radii-cal provided the lowest DC.

Reabilitação estética multidisciplinar. Parte 1: comunicação inicial, modelo de estudo e enceramento diagnóstico / Multidisciplinary esthetic rehabilitation. Part 1: initial communication, study model and diagnostic wax-up

Os cirurgiões-dentistas estão cada vez mais preocupados com oferecer procedimentos restauradores de excelência estética. Isso acontece basicamente por dois fatores: o paciente está cada vez mais exigente e o profissional tem buscado o aperfeiçoamento de técnicas. Assim, as cerâmicas estão cada vez mais presentes no consultório odontológico, por possibilitarem reabilitações com máxima estética e previsibilidade. Atualmente esses materiais possibilitam o rearranjo estético, que pode ser desde pequenos ajustes (fragmentos) até reabilitações extensas. O sucesso do tratamento reabilitador depende de diversos aspectos inerentes ao profissional, paciente e aos materiais que serão utilizados. A escolha de um laboratório com excelência e a boa comunicação com o ceramista tornam-se imprescindíveis para o resultado final de excelência. Para isso, o profissional deve oferecer o máximo de detalhes relacionados ao paciente, mediante fotografias e moldagens. O objetivo deste artigo, a primeira parte de três etapas, é demostrar a comunicação inicial do profissional com o laboratório de prótese, para trilhar um planejamento individual com máxima previsibilidade

Dentists are increasingly concerned to perform restorative procedures with esthetic excellence. Dental ceramics have been used widely for rehabilitation allowing for maximum esthetics and predictability. Currently, these materials can be used for esthetic rearrangement of minor adjustments with fragments of used in extensive rehabilitation. The success of the rehabilitation treatment is dependent on several aspects related to the professional, patient and materials to be used. The choice of a laboratory is essential to the final result and the dentist must have good communication with the ceramist. In this way, the dentist must provide as much detail related to the patient through photography and models. The aim of this paper, the first part of three stages, is to demonstrate the initial communication to the dental lab for planning with a maximum predictability

Degree of conversion of nanofilled and microhybrid composite resins photo-activated by different generations of LEDs

OBJECTIVE:This study aimed at evaluating the degree of conversion (DC) of four composite resins, being one nanofilled and 3 microhybrid resins, photo-activated with second- and third-generation light-emitting diodes (LEDs). MATERIAL AND METHODS: Filtek TM Z350 nanofilled composite resins and Amelogen® Plus, Vit-l-escenceTM and Opallis microhybrid resins were photo-activated with two second-generation LEDs (Radii-cal and Elipar Free LightTM 2) and one third-generation LED (Ultra-Lume LED 5) by continuous light mode, and a quartz halogen-tungsten bulb (QHT, control). After 24 h of storage, the samples were pulverized into fine powder and 5 mg of each material were mixed with 100 mg of potassium bromide (KBr). After homogenization, they were pressed, which resulted in a pellet that was evaluated using an infrared spectromer (Nexus 470, Thermo Nicolet) equipped with TGS detector using diffuse reflectance (32 scans, resolution of 4 cm-1) coupled to a computer. The percentage of unreacted carbon-carbon double bonds (% C=C) was determined from the ratio of absorbance intensities of aliphatic C=C (peak at 1637 cm-1) against internal standard before and after curing of the specimen: aromatic C-C (peak at 1610 cm-1). RESULTS: The ANOVA showed a significant effect on the interaction between the light-curing units (LCUs) and the composite resins (p<0.001). The Tukey’s test showed that the nanofilled resin (FiltekTM Z350) and Opallis when photo-activated by the halogen lamp (QTH) had the lowest DC compared with the other microhybrid composite resins. The DC of the nanofilled resin (FiltekTM Z350) was also lower using LEDs. The highest degrees of conversion were obtained using the third-generation LED and one of second-generation LEDs (Elipar Free LightTM 2). CONCLUSIONS: The nanofilled resin showed the lowest DC, and the Vit-l-escenceTM microhybrid composite resin showed the highest DC. Among the LCUs, it was not possible to establish an order, even though the second-generation LED Radii-cal provided the lowest DC.