Effect of the Case for Carpule as a Visual Passive Distraction Tool on Dental Fear and Anxiety: A Pilot Study.

The present cross-over study aimed to evaluate the effect of a visual passive distraction tool, a case for carpule, in the management of fear and anxiety during invasive dental treatment. Children between the ages of 4 and 8 years that need at least two treatments with inferior alveolar nerve block were selected. All the included children received two treatments at different moments: in one treatment, local anesthesia was performed with a visual passive distraction tool, the crocodile case, for carpule (experimental); in the other treatment, local anesthesia was performed without the device (control). An evaluation of the anxiety levels was performed by measuring the heart rate and salivary cortisol levels. Wilcoxon's nonparametric test was used for a data analysis (p < 0.05). The mean heart rate with the visual passive distraction device fell from 81.8 to 78.1, while the control rose from 91.4 to 100 (p < 0.05). The mean salivary cortisol levels with the visual passive distraction device fell from 2.0 to 1.6, while in the control, they rose from 2.1 to 2.4 (p < 0.05). In conclusion, the crocodile case for carpule as a visual passive distraction device contributed positively to the management of fear and anxiety during inferior alveolar nerve block in children.

Polyethylene terephthalate clamps: Optimization in endodontic and restorative practices.

Background: There is a growing search for innovations in dental materials and instruments and, therefore, an increase need to optimize the instruments used in the absolute isolation. The gold standard procedure contributes significantly to the quality of restorative and endodontic procedures. Thus, the aim of the present study was to evaluate the radiopacity of polyethylene terephthalate polymer clamps and compare them to conventional metal clamps. Material and Methods: The polyethylene terephthalate clamp was developed at the University of Uberaba (Patent application #PI0901719-4, Uberaba, MG, Brazil). Five polyethylene terephthalate clamps and five conventional metal clamps were used. The clamps were positioned, next to an aluminum scale, under the same phosphor plate to perform 3 radiographs. The locator cylinder was set perpendicular to the radiographic films at a focal length of 20 cm and set to 60 kVp and 0.06 seconds. After image processing, optical density values were read using DBWin 5.0.4 software. The mean of the 3 readings taken on each clamp was adopted as the radiodensity of the specimen. The differences between the groups were compared using Student's t-test (p<0.05). Results: Polyethylene terephthalate clamps demonstrated significantly lower radiopacity than conventional metal clamps (p<0.05). Conclusions: Polyethylene terephthalate clamps have lower radiopacity when compared to conventional metal clamps. Key words:Rubber Dams, Dentistry, Operative, Endodontics.

Evaluation of bond strength and thickness of adhesive layer according to the techniques of applying adhesives in composite resin restorations.

Adhesive restorations have increasingly been used in dentistry, and the adhesive system application technique may determine the success of the restorative procedure. The aim of this study was to evaluate the influence of the application technique of two adhesive systems (Clearfil SE Bond and Adper Scotchbond MultiPurpose) on the bond strength and adhesive layer of composite resin restorations. Eight human third molars were selected and prepared with Class I occlusal cavities. The teeth were restored with composite using various application techniques for both adhesives, according to the following groups (n = 10): group 1 (control), systems were applied and adhesive was immediately light activated for 20 seconds without removing excesses; group 2, excess adhesive was removed with a gentle jet of air for 5 seconds; group 3, excess was removed with a dry microbrushtype device; and group 4, a gentle jet of air was applied after the microbrush and then light activation was performed. After this, the teeth were submitted to microtensile testing. For the two systems tested, no statistical differences were observed between groups 1 and 2. Groups 3 and 4 presented higher bond strength values compared with the other studied groups, allowing the conclusion that excess adhesive removal with a dry microbrush could improve bond strength in composite restorations. Predominance of adhesive fracture and thicker adhesive layer were observed via scanning electron microscopy (SEM) in groups 1 and 2. For groups 3 and 4, a mixed failure pattern and thinner adhesive layer were verified. Clinicians should be aware that excess adhesive may negatively affect bond strength, whereas a thin, uniform adhesive layer appears to be favorable.

Effect of 'Try-in' paste removal method on bond strength to lithium disilicate ceramic.

OBJECTIVES: The aim of this study was to evaluate four methods of Try-in paste removal from a lithium disilicate ceramic surface before cementation and assess the influence on bond strength to a resin luting cement. METHODS: Slices of dentine (1.6mm thick) were sectioned from the crown of human third molars and truncated cone shape cavities were made with diamond burs. IPS e.max Press ceramic blocks were obtained for each cavity, etched with hydrofluoric acid and fixed with temporary paste, except for Group G1, which was cemented according to the manufacturer's instructions. Try-in paste was removed from the experimental groups using different techniques: G2, ultrasonic bath in distilled water (5 min); G3, air/water spray (1 min); G4, etched with phosphoric acid (2 min)+air/water spray (30 s) and G5, etched with phosphoric acid before and after hydrofluoric acid application+air/water spray (30s). The ceramic restorations were cemented with the same procedures as G1. Push-out bond strength testing (MPa) was performed in a universal testing machine with a crosshead speed of 0.5mm/min. RESULTS: One way ANOVA and Tukey's test (P<0.05) were applied: G4(19.21)a, G2(17.09)ab, G1(16.82)ab, G3(16.18)ab and G5(15.9)b. The results showed that all of the experimental groups showed remaining particles of Try-in paste. The bond strength in G4 was statistically higher than in G5. No significant difference was shown in the other groups. There was a predominance of adhesive failures between resin cements and ceramics in G5. CONCLUSION: The techniques used were not totally effective at removing the Try-in paste; however, the presence of remaining material did not influence the bond strength of restorations. The methods of temporary paste removal may affect the bond strength of ceramic restorations.

Analysis of the properties of dental cements after exposure to incubation media containing Streptococcus mutans.

AIM: Indirect restorations are increasingly used in dentistry, and the cementation interface is possibly the most critical region of the work. The objective of the present work was to evaluate the influence of exposure to a culture medium containing S. mutans on the hardness and solubility of four different cementing agents (zinc phosphate, glass ionomer, glass ionomer modified with resin and resin cement). MATERIALS AND METHODS: Test specimens composed of these cements were exposed for 30 days in a culture medium containing S. mutans. After leaching, the test materials were assessed in terms of their solubility (loss of mass) and Knoop (KHN) microhardness. Changes in surface morphology were identified using scanning electron microscopy (SEM). RESULTS: The resin cement showed no significant solubility and its hardness increased following exposure and leaching, while the zinc phosphate cement was the most soluble and its hardness decreased after exposure to the culture medium. SEM analyses identified morphological alterations on the surfaces of the test materials that were compatible with the solubility results. CONCLUSION: It is concluded that resinous cements perform better than water-based cements when exposed to acidic conditions. CLINICAL SIGNIFICANCE: The effects of acids from Streptococcus mutans can interfere with the efficiency and properties of some cements used for fixation of indirect restorations, exposed to the buccal environment.

Avaliação in vitro das alterações verificadas em canais radiculares artificiais curvos preparados por dois sistemas rotatórios / In vitro evaluation of shape changes in curved artificial root canals prepared with two rotary systems

O objetivo desta pesquisa experimental in vitro foi analisar comparativamente as deformações no canal radicular apóso uso do sistema rotatório de NiTi ProTaper Universal, ProDesign e técnicas híbridas utilizando os dois sistemas. Foram utilizados e instrumentados, setenta e cinco blocos com canais radiculares artificiais, divididos em cinco grupos(n=15). Para o grupo 1, os preparos foram realizados pelo sistema ProTaper Universal, utilizando a lima F3 no preparo apical. Para o grupo 2, utilizou-se o sistema ProDesign com preparo apical usando a lima 30/0,2. Para o grupo 3,os preparos foram realizados pelo sistema ProTaper Universal,utilizando a lima F2 no preparo apical. Para o grupo 4, os sistemas ProDesign e ProTaper foram utilizado sem conjunto com preparo realizado com a lima F2. Para o grupo 5, os sistemas ProDesign e ProTaper foram utilizados em conjunto com preparo apical realizado com as limas F1 e F2. As brocas de Gates-Glidden #5, #4, #3, #2 e#1 realizaram o preparo da porção reta de todos os canais,caracterizando o preparo cervicoapical. Foram analisados a diferença e o quociente da quantidade de resina removida nos seis milímetros de curvatura, aferidos tanto na parte interna quanto na parte externa. Zip e elbow foram quantificados pela forma final, após instrumentação em cada grupo testado. Para análise dos dados utilizou-se os testes paramétricos (ANOVA p<0,05), não paramétrico Kruskal--Wallis (p<0,05) e qui-quadrado (p<0,05). Para diferença e quociente, verificou-se melhores formas para os grupos 2 e3. Através da análise quantitativa e qualitativa, observou-se melhores preparos com o sistema ProDesign e ProTaperUniversal com preparo apical utilizando lima F2.

The aim of this in vitro experimental analysis was to comparethe changes in canal shape after the use of ProTaper UniversalNiTi rotary system, ProDesign system, and a hybridtechnique using both systems. A total of seventy-five simulatedroot canals were prepared and divided into five groups(n = 15). For Group 1, the ProTaper Universal System withapical preparation file F3 was used. For Group 2, ProDesignSystem with apical preparation using file 30/0.2 was used.For Group 3, ProTaper Universal System with apical preparationwith file F2 was applied. For Group 4, ProDesign Systemand ProTaper Universal System with apical preparationwith file F2 were applied. For Group 5, ProDesign Systemand ProTaper Universal System with apical preparation F1and F2 were used. All instrumentation was performed withthe help of Gates-Glidden drills #5, #4, #3, #2 and #1 accordingto crow-down preparation. The difference and thequotient the amount of removed resin were analyzed withinsix millimeters of the canal curvature, measured for both innerand outer walls. The amount of zip and elbow apical formationand mean final shape for each type tested were analyzed.Data were analyzed using parametric tests (ANOVA p<0.05),non-parametric test Kruskal-Wallis (p<0.05) and Chi-squaretest (p<0.05). When difference, quotient and final mean shapewere analyzed, the best preparations were observed in groups2 and 3. Through qualitative and quantitative analysis, thebest preparations were obtained with ProDesign System andProTaper Universal System with apical preparation file F2.

Microstructure and mineral composition of dental enamel of permanent and deciduous teeth.

PURPOSE: This study evaluated and compared in vitro the microstructure and mineral composition of permanent and deciduous teeth's dental enamel. METHODS: Sound third molars (n = 12) and second primary molars (n = 12) were selected and randomly assigned to the following groups, according to the analysis method performed (n = 4): Scanning electron microscopy (SEM), X-Ray diffraction (XRD) and Energy dispersive X-ray spectrometer (EDS). Qualitative and quantitative comparisons of the dental enamel were done. The microscopic findings were analyzed statistically by a nonparametric test (Kruskal-Wallis). The measurements of the prisms number and thickness were done in SEM photomicrographs. The relative amounts of calcium (Ca) and phosphorus (P) were determined by EDS investigation. Chemical phases present in both types of teeth were observed by the XRD analysis. RESULTS: The mean thickness measurements observed in the deciduous teeth enamel was 1.14 mm and in the permanent teeth enamel was 2.58 mm. The mean rod head diameter in deciduous teeth was statistically similar to that of permanent teeth enamel, and a slightly decrease from the outer enamel surface to the region next to the enamel-dentine junction was assessed. The numerical density of enamel rods was higher in the deciduous teeth, mainly near EDJ, that showed statistically significant difference. The percentage of Ca and P was higher in the permanent teeth enamel. CONCLUSIONS: The primary enamel structure showed a lower level of Ca and P, thinner thickness and higher numerical density of rods.

Effect of surface treatment and storage on the bond strength of different ceramic systems

Aim: The aim of this study was to evaluate the micro shear bond strength of different ceramic systems – IPS Empress 2, Cergogold, In-Ceram Alumina and Cercon - and a dual luting agent. Methods: Twelve specimens of each ceramic were fabricated and divided according different surface treatments: Group 1: No additional treatment was applied to the ceramic surface; Group 2: Ceramics were etched with 9.5% hydrofluoric acid; Group 3: specimens treated with airborne particle abrasion for each ceramic system in accordance with manufacturer’s instructions (n=20). The tests were performed after 24 h or after water storage for 6 months. Data were then assessed statistically using the 3-way ANOVA and the Tukey’s test (P<0.05). Results: For Cergogold and IPS Empress 2 systems, the treatments performed with airborne particle abrasion and hydrofluoric acid showed no significant differences from each other, and both were superior to the groups without treatment. For Cercon and In-Ceram ceramics, no differences were found among the groups (P<0.05). When the surface was treated with hydrofluoric acid, the highest bond strength was found to IPS Empress 2 in the 6-month storage period (P<0.05). Conclusion: Lower bond strength values were only observed with IPS Empress 2 ceramic for the control group in the 6-month storage (P<0.05).

Pulp reactions in human teeth capped with self-etching or total-etching adhesive systems.

OBJECTIVE: Restorative procedures of the dentin-pulp complex stimulate damages that, depending on the technique and materials used, may induce pulpal reactions. The purpose of this study was to evaluate immunochemistry, morphologic, and morphometric pulpal alterations of human teeth pulps capped with self-etching or total-etching adhesive systems. METHOD AND MATERIALS: Thirty human third molars were restored with a resin-based composite and adhesive system, either Clearfil (Kuraray; n = 10) or Scotchbond (3M ESPE; n = 10). After 7, 30, or 60 days, the teeth were extracted and longitudinally sectioned. The pulps were removed for histopathologic and immunochemistry evaluation for interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, and inducible nitric oxide synthase (iNOS). RESULTS: The density of fibrous connective tissue was significantly higher after 30 days in both groups (P < .001). Congestion, hemorrhage, calcification, and swelling of the odontoblasts were similar in both groups. The total capillary area was significantly higher after 7 and 30 days in both groups. Positive immunoreactions for iNOS were found in 1 case (20%) of the 30-day Scotchbond group. Immunoreactions for IFN-gamma were positive in a few cells in 1 case (20%) of the 7-day Clearfil group. There were no positive immunoreactions for TNF-alpha in any case. CONCLUSION: No inflammatory reactions, necrotic areas, or severe immunoreactions for proinflammatory cytokines were found, suggesting biocompatibility of self-etching or total-etching adhesive systems when placed directly on dentin.

O condicionamento ácido prévio ainda é indispensável para a odontologia adesiva? / Is previous total etching still indispensable for the adhesive dentistry?

O objetivo deste trabalho foi avaliar as características dos sistemas adesivos disponíveis atualmente considerando a aplicação ou não do condicionamento prévio com ácido fosfórico. O conhecimento das estruturas e o tratamento adequado do substrato dental são fundamentais para utilização dos adesivos convencionais. Os sistemas adesivos autocondicionantes possuem técnica simplificada dispensando o condicionamento ácido prévio. O profissional deverá ter conhecimento dos mecanismos de adesão ao substrato dental, experiência clínica e domínio da técnica de aplicação do adesivo escolhido. O condicionamento ácido prévio não deve ser considerado indispensável na Odontologia adesiva atual.

Comparação de técnicas de mensuração da infiltração marginal em restaurações de resina composta / Comparison of measurement techniques of marginal leakage in composite restorations

O objetivo deste trabalho foi aplicar dois métodos de mensuração da infiltração marginal da resina composta com intuito de verificar qual delas permite maior confiabilidade dos resultados. Foram confeccionadas cavidades de classe V, com margem cervical em dentina, restauradas com o sistema restaurador Single Bond/Z250. As medidas de infiltração dos grupos foram realizadas por meio de dois métodos: análise por escores e análise por programa de computador específico (Image Tool), através do qual foram realizadas medidas para obtenção de valores em milímetros. A análise estatística demonstrou que não houve compatibilidade dos resultados obtidos através das duas técnicas.

Técnicas alternativas para amenizar os efeitos gerados durante a contração da resina composta / Alternative technique to minimize the effects caused by the shrinkage of the composite resin

O objetivo deste trabalho foi aplicar técnicas alternativas de inserção e fotoativação de resina com o intuito de amenizar os efeitos da contração de polimerização, avaliando a infiltração marginal. Foram confeccionadas cavidades de classe V, com margem cervical em dentina, restauradas com o sistema restaurador Single Bond/Z250. Os dentes foram divididos em quatro grupos, de acordo com a técnica de inserção da resina (incremental ou em incremento único) e formas de fotoativação (máxima intensidade ou gradual). As técnicas de inserção incremental e fotoativação gradual, quando associadas, diminuíram os efeitos gerados durante a contração de polimerização da resina

Avaliação da infiltração marginal em restaurações com resina composta variando-se os métodos de fotoativação / Evaluation of the marginal leakage in restorations with composite, varying the light cure methods

O presente estudo se propôs a avaliar a infiltração marginal em restaurações realizadas pelas técnicas de fotoativação gradual e com máxima intensidade. Foram confeccionadas 32 cavidades de classe V, com margens em esmalte, dimensões ocluso-cervical de 2,0mm, mésio-distal de 2,0mm e profundidade de 1,5mm. As cavidades foram restauradas com o sistema restaurador Single Bond/Z-250 (3M do Brasil). Os dentes foram divididos em dois grupos. Os grupos diferiam entre si de acordo com a técnica de fotoativação da resina. Os resultados, mostraram que a técnica de fotoativação gradual apresentou índice de infiltração estatisticamente menor em relação à técnica de fotoativação com máxima intensidade

Infiltraçäo marginal em restauraçöes utilizando diferentes métodos de inserçäo da resina / Marginal leakage in restorations according to different composite insertion methods

O presente estudo se propôs a avaliar a infiltraçäo marginal em restauraçöes realizadas pelas técnicas de incremento único e incremental. Foram confeccionadas 32 cavidades de classe V, com margens em esmalte, dimensöes ocluso-cervicais de 2,0mm, mésio-distais de 2,0mm e profundidade de 1,5mm. As cavidades foram restauradas com o sistema restaurador Single Bond/Z250 (3M do Brasil). Os dentes foram divididos em dois grupos. Os grupos diferiam entre si de acordo com a técnica de inserçäo da resina na cavidade. Os resultados mostraram que a técnica incremental apresentou índice de infiltraçäo estatisticamente menor em relaçäo à técnica de incremento único

Avaliação da infiltração na margem cervical em dentina de restaurações classe V, variando-se as técnicas de inserção e fotoativação da resina composta / Evaluation of the leakage in the dentin cervical margin of restorations class V being varied the insert and polymerization techniques of the composed resin

O objetivo desse estudo foi avaliar a infiltração na margem cervical em dentina em restaurações realizadas pelas técnicas de incremento único e incremental, associadas ou não à fotoativação gradual. Foram confeccionadas 64 cavidades de classe V, com margens oclusal, mesial e distal em esmalte e margem cervical em dentina, com dimensões ocluso-cervical de 2,0 mm, mésio-distal de 2,0mm e profundidade de 1,5mm. As cavidades foram restauradas com o sistema restaurador Single-Bond/Z250 (3M do Brasil). A aplicação do sistema adesivo foi realizada de acordo com as instruções do fabricante. Os dentes foram divididos em quatro grupos. Os grupos diferiam entre si de acordo com a técnica de inserção da resina na cavidade (incremental ou em incremento único) e de acordo com as formas de fotoativação (gradual, variando a intensidade através da distância da fonte de luz em relação à restauração). Os grupos foram assim divididos: Grupo 1 - técnica de incremento único, associada à ativação com máxima intensidade de luz (aproximação máxima); Grupo 2 - técnica incremental e fotoativação com máxima intensidade de luz; Grupo 3 - técnica de incremento único, associada à fotoativação gradual; e Grupo 4 - técnica incremental, associada à fotoativação gradual. Os corpos foram submetidos...