Comparison of microtomography and optical coherence tomography on apical endodontic filling analysis.

OBJECTIVES: To comparein vitro differences in the apical filling regarding working length (WL) change and presence of voids and to validate optical coherence tomography (OCT) in comparison with computerized microtomography (µCT) for the detection of failures in the apical filling. METHODS: Forty-five uniradicular teeth with round canals, divided into groups (n = 15) following the obturation protocols: LC (lateral condensation), TMC (thermomechanical compaction) and SC (single cone). Samples were scanned using µCT (parameters: 80 kV, 222 µA, and resolution of 11 µm), OCT (parameters: SSOCT, 1300 nm and axial resolution of 12 µm), and periapical digital radiography. The images were analyzsed by two blind and calibrated observers using ImageJ software to measure the boundary of the obturation WL and voids presence. Categorical and metric data were submitted to inferential analysis, and the validity of the OCT as a diagnostic test was assessed with performance and reliability tests. RESULTS: The WL average remained constant for all obturation techniques and image methods. OCT showed adequate sensitivity and specificity to detect voids in the WL of apical obturations in vitro in comparison with µCT. Both image methods found a higher number of voids for LC technique (µCT p = 0.011/OCT p = 0.002). CONCLUSIONS: OCT can be used in apical obturation voids assessment and the LC technique revealed more voids with larger dimensions.

Evaluation of dental enamel caries assessment using Quantitative Light Induced Fluorescence and Optical Coherence Tomography.

An in vitro study of morphological alterations between sound dental structure and artificially induced white spot lesions in human teeth, was performed through the loss of fluorescence by Quantitative Light-Induced Fluorescence (QLF) and the alterations of the light attenuation coefficient by Optical Coherence Tomography (OCT). To analyze the OCT images using a commercially available system, a special algorithm was applied, whereas the QLF images were analyzed using the software available in the commercial system employed. When analyzing the sound region against white spot lesions region by QLF, a reduction in the fluorescence intensity was observed, whilst an increase of light attenuation by the OCT system occurred. Comparison of the percentage of alteration between optical properties of sound and artificial enamel caries regions showed that OCT processed images through the attenuation of light enhanced the tooth optical alterations more than fluorescence detected by QLF System. QLF versus OCT imaging of enamel caries: a photonics assessment.

Enamel erosion and prevention efficacy characterized by confocal laser scanning microscope.

The aim of this study was to evaluate the erosion-inhibiting effect of two toothpastes on the development of erosion-like lesions, by a confocal laser scanning microscope (CLSM). Forty human enamel blocks were divided into five groups (n = 8), in accordance to evaluate the GC MI Paste Plus and Oral B with stannous fluoride, applied as slurries and associated with toothbrush. Specimens were submitted to an erosion challenge from citric acid (0.5%, pH = 2.8), for 5 min, six times a day, alternating in artificial saliva immersions. Reference group was not exposed to treatment. Part of specimens (Groups 02 and 03) was exposed twice daily just to slurries, for 2 min, therefore specimens from Groups 04 and 05 were also abraded, for 30 s. The enamel surfaces were morphological characterized using CLSM images, with mineral loss being measured using the resulting 3D images referenced to an un-challenged portion of the sample. Step values were compared using the one-way ANOVA test. CLSM was shown to be a viable, noncontact, and simple technique to characterize eroded surfaces. The statistical difference in the step size was significant between the groups (P = 0.001) and using multiple comparisons a statistically significant protective effect of toothpastes was shown when these were applied as slurries. Although groups submitted to tooth brush showed mineral loss similar to reference control group, due to the damages of abrasion associated.

Optical coherence tomography as an auxiliary tool for the screening of radiation-related caries.

OBJECTIVE: The aim of this study was to evaluate the morphological alterations of radiation-related caries using optical coherence tomography. METHODS: Thirty-six extracted teeth from 11 patients who had undergone radiotherapy were sectioned in the sagittal axis in the center of the carious lesion, and 100 µm thick sections were obtained from each specimen. One sample from each tooth was investigated by an optical coherence tomography (OCT) system, and the results were compared with histological images from polarized light microscopy. RESULTS: In OCT dentin caries images, the demineralized area appeared as a white region, whereas the translucent zone appeared as a dark area, a similar pattern also seen in coronal caries. In noncavitated enamel lesions clinically observed as brown discoloration, the area of high porosity, and also the dark color, absorbs part of the light, resulting in a dark pattern. Finally, the involvement of dentin-enamel junction (DEJ) or cement-enamel junction (CEJ) could be clearly observed, when present and marked alterations along the CEJ could be noted, as junction continuity loss, gap formation, and mineral loss tissue. CONCLUSIONS: The OCT technique was able to characterize radiation-related caries, from a morphological point of view. Also demonstrated was its potential benefit for use in the clinical monitoring of radiation-related carious process.

A laserterapia na odontologia: propriedades, indicações e aspectos atuais / The lasertherapy in Dentistry: properties, indications and current aspects

Propõe-se com essa revisão da literatura mostrar a relevância da aplicabilidade do laser de baixa intensidade na clínica odontológica, bem como suas principais indicações e aspectos atuais. Atualmente a laserterapia representa uma opção extraordinária disponível na clínica odontológica diária nas mais diversas especialidades. Os efeitos e mecanismos de ação da luz laser são complexos e alvos de inúmeras pesquisas com vistas a um melhor delineamento de suas formas de aplicação e indicações. Dessa forma, apesar da segurança na sua utilização e de seus efeitos bioestimulantes bem conhecidos, a literatura consultada mostrou a existência de algumas questões ainda duvidosas com relação aos resultados obtidos no tecido vivo quando submetidos à irradiação.

The proposition this study is show the relevance of low intensity laser use in dentistry and comment its main indicatons and current aspects. Currently the lasertherapy represent a excellent available option to be used in the dentistry clinics. The effects and action mechanism of laser light are complex and have been a frequent target on various research in order to reach the perfection on its uses and applications. Thus, although its known safety usage and biostimulation effects, the studies show the existence of unanswered doubts related to the effects about living tissues submitted to irradiation.

Avaliação da resistência ao cisalhamento de diferentes sistemas adesivos monocomponentes ao esmalte humano / Evaluation of shear bond strength of different adhesives system to human enamel

Esta pesquisa objetivou comparar a resistência de união ao cisalhamento de diferentes sistemas adesivos monocomponentes ao esmalte humano, analisando o padrão de fratura. Foram utilizados 40 hemifaces de terceiros molares humanos, os quais foram incluídos em tubos de PVC com resina acrílica, sendo exposta uma superfície aplainada do esmalte dentário. Os espécimes foram divididos em 4 grupos: G1 -Single Bond® (3M-ESPE); G2 – Prime & Bond® 2.1 (Dentsply); G3 – Magic Bond® (Ivoclar Vigodent);G4 – Master Bond® (Biodinâmica). Com o auxílio de uma peça plástica, confeccionou-se um cilindro de resina com 4,2mm de diâmetro e a descolagem foi realizada em máquina Kratos, com velocidade de 1mm/min. Os dados foram submetidos ao teste Kruskal-Wallis, não apresentando diferenças estatisticamente significantes entre os grupos (p>0,05). Na análise do tipo de fraturas constatou-se uma predominância da fratura adesiva na interface compósito/adesivo.

Resistencia al cizallamiento de dos sistemas adhesivos autocondicionantes en dientes decíduos - estudio in vitro / Two esistance shear adhesive systems auto conditioners in deciduous teeth - study in vitro

El objetivo de este trabajo fue comparar la fuerza de adhesión de dos sistemas adhesivos dentinários en dientes deciduos. Treinta y seis dientes deciduos fueron seleccionados y almacenados en agua en temperatura ambiente por un período no superior a 6 meses después de la extracción. Los dientes fueron incluidos en resina acrílica de autocurado y desgastados hasta exponer la dentina. Los especimenes fueron seleccionados y divididos en 4 grupos (n = 9), en cada uno de ellos fue demarcada una área de 2mm de diámetro, donde se aplicaron los adhesivos: Adhese ® y Clearfil SE Bond®, para adherir conos de resina compuesta y compómero que fueron construidos para el experimento. Fueron sometidos a prueba las siguientes combinaciones: G1 = Adhese® + Filtek Z-250®, G2 = Adhese® + Dyract®, G3 = Clearfil SE Bond® + Filtek Z-250® and G4 = Clearfil SE Bond® + Dyract®. Después de 48 horas en agua destilada, se realizó la prueba de resistencia al cizallamiento (1.0 mm/minuto). Finalizada la prueba en los 4 grupos, los especimenes fueron observados en estéreo microscopio para verificar el tipo de fractura. La fuerza de adhesión varió de 3.77 a 7.90 MPa. No fueron observadas diferencias estadísticamente significantes (p > 0.05) y el tipo de fractura mas común fue la adhesiva. El mayor valor de adhesión fue encontrado en el G4 y el menor en el G1, no se observaron diferencias estadísticamente significativas entre los grupos

The aim of this study was to compare the shear bond strengths of two adhesive systems to the dentine of primary teeth. Thirty-six human non-carious primary teeth were collected and stored in water at room temperature for no longer than 6 months after extraction. The teeth were embedded in acrylic resin and the dentin was exposed (carbide paper 120, 400 and 600 grit) and the specimens were randomly assigned in four groups (n=9). A 2mm-diameter dentin bonding site was demarcated, the adhesive systems (Adhese® and Clearfil SE Bond®) were applied and resin composite and compomers cones were bonded. The following 4 combinations were tested: G1 = Adhese® + Filtek Z-250®, G2 = Adhese® + Dyract®, G3 = Clearfil SE Bond® + Filtek Z-250® and G4 = Clearfil SE Bond® + Dyract®. After 48 hours in distilled water, tensile bond strength was tested to failure (1.0 mm/minute). After measuring shear bond strengths, specimens were prepared for stereomicroscopy evaluation and identification of failure type. Shear bond strength values ranged from 3.77 to 7.90 MPa. No statistically significant differences were found among the shear bond strengths (p > 0.05) of the groups and the mode of failure was mostly adhesive. The highest shear bond strength was achieved by G4 and the lowest by G1 and no differences statistically between the groups were observed

Relato de caso com análise de cálculos dentários supragengivais humanos através das técnicas de difração de raios X e espectroscopia Raman / Analyse of human supragingival dental calculus by x-ray diffraction and spectroscopy Raman techniques - case report

A composição química dos cálculos dentários já tem sido discutida na literatura, bem como seu processo de deposição mineral ao longo do tempo. Entretanto, diante de um caso de grandes proporções, tem-se o objetivo de relatar o caso clínico e aprofundar a discussão da análise química do material coletado. 0 paciente, sexo masculino, 42 anos, apresentava cinco elementos dentários com acúmulo de cálculos com dimensões macroscópicas acima da média. 0 tratamento estabelecido foi a remoção cirúrgica dos dentes associados aos cálculos e posterior investigação da composição e da cristalinidade segundo análise das técnicas através de espectroscopia Raman e difração de raios X. Os resultados mostraram diferenças obscuras na espectroscopia Raman devido à fluorescência natural dos compostos e através da difração de raios X foi possível observar a presença da hidroxiapatita principalmente na superfície interna, o p fosfato tricálcio com maior concentração externa e a baixa concentração de bruxita em ambos os casos. Os resultados descritos corroboram com a descrição da literatura e podem ser explicados devido ao diferente tempo de envelhecimento do cálculo, nas regiões internas e externas. 0 uso das técnicas de caracterização químicas são ferramentas que têm se mostrado úteis em várias áreas de pesquisa, inclusive e cada vez mais, enriquecendo diagnósticos clínicos.

The chemical composition of dental calculus has already been discussed in the literature, as well as the process of mineral deposition over time. However, based on an high dimensions case, has the objective of describing the clinical case, and deepen the discussion of the chemical analysis of material collected. The male patient, 42 years old, presents five dental elements with accumulation of calculations with macroscopic dimensions above average. The surgical extraction of the teeth associated with the calculations was established, and further investigation of the composition and crystallinity second analysis techniques Raman spectroscopy and by X-ray diffraction. The results showed obscure differences by the Raman spectroscopy due to fluorescence and X-ray diffraction was possible to observe mainly of hydroxyapatite on the inner surface, the whitlockite with the highest concentration outside, and the low concentration of brushite in both cases. The results described corroborate the description of the literature and can be explained due to different aging time of the calculation in the regions internal and external. The use of characterization techniques have been showed fuseful in different research areas, and may enrich the clinical diagnosis.

Avaliação da resistência ao cisalhamento de adesivos monocomponentes em dentes bovinos / Shear bond strength of one-bottle adhesive systems in bovine teeth

O objetivo deste estudo foi comparar a resistência de união ao cisalhamento de diferentes sistemas adesivos monocomponentes ao esmalte bovino. Foram utilizados 48 incisivos bovinos, os quais foram incluídos em tubos de PVC com resina acrílica e gesso, sendo exposta uma superfície aplainada do esmalte dentário. Os espécimes foram divididos em 4 grupos (n=12) e tratados com cada um dos seguintes sistemas adesivos: G1 - Single Bond (3M-ESPE); G2 - Prime&Bond 2.1 (Dentsply); G3 - Magic Bond (Vigodent); G4 - Master Bond (Biodinâmica). Confeccionou-se um cilindro de resina composta com 4,2mm de diâmetro e a descolagem foi realizada em máquina Kratos 2000, com velocidade de 1mm/min. Os resultados foram submetidos ao teste de Kruskal Wallis (p<0,05), não existindo diferença estatisticamente significante entre os grupos.

Perfil da pesquisa científica em odontologia realizada no Brasil / The scientific dental research profile in Brazil

É inegável o avanço científico observado na odontologia brasileira. Nesse sentido, a reunião anual da Sociedade Brasileira de Pesquisa Odontológica (SBPqO) é o maior e o mais importante encontro de pesquisadores nacionais. Este estudo objetivou determinar o perfil da pesquisa em odontologia realizado nas instituições brasileiras. Realizou-seum estudo retrospectivo, por meio da documentação indireta,através da análise dos trabalhos apresentados na 20a reunião anual da SBPqO. Foram avaliados 1.905 estudos, os quais foram classificados quanto à área de conhecimento do CNPq, à região e estado do país, à instituição, ao tipo de estudo e ao recebimento de fomento. Pesquisas envolvendo materiais dentários foram as mais prevalentes, com 34,4 porcento do total. A região sudeste concentrou o maior número de trabalhos(76,4 porcento), sendo o Estado de São Paulo responsável por 59,4 por cento da produção científica nacional. As instituições estaduais centralizaram 55,5 por cento das pesquisas, enquanto as federais,19,7 por cento do total de trabalhos. Quanto ao tipo de estudo, 70,6 por cento foram trabalhos experimentais e 29,4 por cento, observacionais. Com relação à obtenção de fomento, apenas 18,3 por cento dos trabalhos mencionaram ter recebido apoio de órgãos governamentais defomento à pesquisa. Conclui-se que há uma discrepância interregional e interestadual na produção científica brasileira, sendo as instituições públicas, a despeito das dificuldades,responsáveis pela maioria das pesquisas odontológicas desenvolvidas no Brasil