Mutation of dentin sialophosphoprotein and hereditary malformations of dentin / 中华口腔医学杂志

The classification as well as the clinical manifestations of hereditary malformations of dentin are of great concern and have been deeply elucidated. The understanding of its genetic basis also increases progressively. Dentin sialophosphoprotein (DSPP) is the pathogenic gene of dentinogenesis imperfecta type Ⅱ, dentinogenesis imperfecta type Ⅲ and dentin dysplasia type Ⅱ. In this article, the classification of DSPP mutations as well as the resultant dysfunction of the mutant DSPP are summarized respectively and the corresponding clinical manifestations are analyzed. This work will provide a reference for the diagnosis and treatment of hereditary malformations of dentin.

Is it necessary to pre-treat Dentine before GIC Restorations? Evidence from an in Vitro Study / É necessário pré tratar a dentina antes das restaurações de CIV? Evidência de um estudo in vitro

ABSTRACT The aim of this study was to assess the influence of differentpretreatmentapproaches on glass ionomer cement (GIC)bond strength (BS) to dentine. Sixty bovine incisors wereallocated into six groups according to substrate - sound orcariesaffecteddentine; and substrate pretreatmentapproach -no conditioning (control), polyacrylic acid for 10 s andphosphoric acid for 7 s. Teeth in the cariesaffecteddentinegroup were previously submitted to cariogenic pHcyclingchallenge. After dentine pretreatment,according to experi mentalgroups, polyethylene tubes were placed on flat dentinesurfaces and filled with GIC. Teeth were stored in distilledwater for 24 h at 37 °C and then submitted to microshear test(0.5 mm/min). Failure pattern analysis was performed understereomicroscope (400x). Data were analysed using twowayANOVA and Tukey's test (α=5%). Statistically significantdifferences were found for the pretreatmentapproach,regardless of substrate (p<0.001). The polyacrylic acid groupand control group had similar BS values, and were both betterthan the phosphoric acid group. In general, GIC had betterbonding performance in sound dentine than in cariesaffecteddentine. In conclusion, dentine pretreatmentwith polyacrylicacid did not improve the performance of GIC restoration onclinically relevant substrates.

RESUMO O objetivo deste estudo foi avaliar a influência de diferentesprétratamentosna resistência de união (RU) de cimentos deionômero de vidro (CIV) a dentina. Sessenta incisivos bovinosforam alocados em 6 grupos de acordo com o substrato -hígido ou cariado; e com a abordagem de prétratamento-sem condicionamento (controle), ácido poliacrílico por 10 s, eácido fosfórico por 7 s. Os dentes pertencentes aos grupos dedentina cariada foram previamente submetidos ao desafiocariogênico por meio da ciclagem de pH. Após o prétratamentoda dentina, de acordo com os grupos experimentais,tubos de polietileno foram colocados sobre superfícies planas dedentina e preenchidos com CIV. Os dentes foram armazenadosem água destilada por 24 h a 37°C e então submetidos ao testede microcisalhamento (0,5 mm/min). A análise do padrão defratura foi realizada em estereomicroscópio (400x). Os dadosobtidos foram analisados usando ANOVA de dois fatores e testede Tukey (α=5%). Diferença estatisticamente significante foiencontrada para as diferentes abordagens de prétratamento,independente do substrato (pp<0,001). Aplicação de ácidopoliacrílico resultou em valores de RU similares aos do grupocontrole. Entretanto, ambos os grupos mostraram um melhordesempenho quando comparado a aplicação de ácidofosfórico. De forma geral, CIV apresentou melho5 desempenhoadesivo em dentina sadia quando comparada a dentinacariada. Em conclusão, o prétratamentoem dentina comácido poliacrílico não melhora o desempenho das restauraçõesde CIV em substratos clinicamente relevantes.

Biodentine Induce Proteínas Apoptóticas Caspasa 3 y PARP-1 en Células de la Pulpa Dental Humana / Biodentine Induces Apoptotic Proteins Caspase 3 and PARP - 1 on Human Dental Pulp Cells

RESUMEN: Las patologías pulpares han sido un verdadero reto para la odontología principalmente por su tratamiento. Actualmente, existen numerosos biomateriales en el mercado que reportan tener propiedades inherentes en los tejidos dentarios. Sin embargo, diferentes estudios sobre múltiples líneas celulares expuestas a estos biomateriales demuestran resultados controversiales como biocompatiblidad y citotoxicidad celular. Biodentine, es un cemento endodóntico en base a silicatos cálcico de múltiples aplicaciones, que prestaría propiedades de biocompatibilidad como bioactividad celular, características que le permitirían incluso ser utilizado en contacto directo con la pulpa dental. El objetivo de este estudio es la evaluación in-vitro de Biodentine, sobre cultivos de células de la pulpa dental humana (CCPDH). Se prepararon discos de cemento de Biodentine™ de 2 x 6 mm, los que se expusieron a cultivos de células aisladas de la pulpa dental humana. Luego de 24, 48 y 72 horas de exposición, se realizaron ensayos de viabilidad celular utilizando el método colorimétrico MTT. También se realizaron ensayos de expresión proteica de dos proteínas involucradas en la vía de señalización de la apoptosis celular: Caspasa - 3 clivada y Poli (ADP-Ribosa) Polimerasa, PARP - 1. Existen diferencias estadísticamente significativas (p<0,05) en los ensayos de viabilidad celular entre las células expuestas a Biodentine y el grupo control, como también a medida que aumenta el tiempo de exposición (p<0,05). Por otra parte, también existen diferencias significativas (p<0,05) en la expresión de PARP- 1 en los grupos sometidos a Biodentine. Los resultados obtenidos en este estudio demuestran que Biodentine genera citotoxicidad celular en cultivos celulares de pulpa dental humana, por disminución de la viabilidad celular como por la expresión de proteínas apoptóticas. Es por esto que la utilización de este biomaterial debería ser estudiado y considerarse en cada caso clínico, especialmente como recubridor pulpar directo.

ABSTRACT: Oral pathologies have been a real challenge for dentistry, mainly due to its treatment. Currently, there are numerous biomaterials on the market that may present inherent properties in dental tissues. However, studies on multiple cell lines are based on biocompatible results such as biocompatibility and cellular cytotoxicity. Biodentine is endodontic cement based on calcium silicates of multiple applications, which would provide biocompatibility properties as cellular bioactivity, characteristics that will allow it to be used in direct contact with the dental pulp. The objective of this study is the in vitro evaluation of Biodentine, on cultures of cells of the human dental pulp (HDPC). Biodentine cement disks of 2 x 6 mm were prepared, and HDPC culture plates were introduced. After 24, 48 and 72 hours of exposure, cell viability tests were performed using the MTT colorimetric method. On the other hand, protein expression assays of two proteins involved in the signaling pathway of cell apoptosis Caspase-3 cleaved (cas-3 clv) and PARP-1 are carried out. There are statistically significant differences (p <0,05) in the cell viability tests between Biodentine and control group, as well as the exposure time increases (p <0,05). Otherwise, there are also significant differences (p <0,05) in the expression of PARP-1 in the groups, sometimes a Biodentine. The results in this study that Biodentine generates a cellular cytotoxicity in HDPC cultures, therefore, cell viability as the expression of apoptotic proteins. This is why the use of this biomaterial should be studied for each particular clinical case, especially as a direct pulp capping agent.

Characteristics and severity of tooth wear in 2 to 5-year-old kindergarten children in Medellin / Facetas de desgaste y características de severidad en niños de 2 a 5 años de un jardín infantil, Medellín

The aim of the present study was to identify the characteristics and severity of tooth wear in children aged 2 to 5 years attending a kindergarten in the city of Medellin. The study population comprised 92 children aged 2 to 5 years attending a kindergarten in Medellin; the final sample included 86 children selected using a non-probabilistic sampling method. All assessments were performed using the index devised by Hansson and Nilner (1989). Prevalence of tooth wear in the studied population was 100%. The observed results confirm previous findings showing that the severity of tooth wear is proportionally related with increase in age, and is mainly due to the physiological wear of teeth. No significant differences in tooth wear facets were observed among the different types of teeth (incisors, canines, molars). It is necessary to develop validated, precise, and comparable indices that allow establishing the etiology and orienting treatment of non-physiological tooth wear.

El objetivo del estudio fue identificar las facetas de desgaste y las características de severidad en niños de 2 a 5 años de un jardín infantil de la ciudad de Medellín. El estudio incluyó 92 niños entre los 2 y 5 años de un jardín infantil de la ciudad de Medellín, con una muestra final de 86 seleccionados a partir de un muestreo no probabilístico. Se utilizó como instrumento el índice propuesto por Hansson y Nilner (1989). El 100% (86) de los niños evaluados presentaron facetas de desgaste. Los resultados encontrados confirman datos previos en cuanto a que las severidades de las facetas de desgaste dentario están relacionadas proporcionalmente con el aumento de edad y se deben principalmente al desgaste fisiológico de los dientes. No se encontraron diferencias significativas en la prevalencia o severidad de desgaste entre los grupos anatómicos dentarios (incisivos, caninos y molares). Es necesario establecer índices validados, precisos y comparables para evaluar la etiología y orientar hacia la solución de las causas no fisiológicas.

Ideal Concentration of Advanced-Platelet Rich Fibrin (A-PRF) Conditioned Media for Human Dental Pulp Stem Cells Differentiation

Abstract Objective: To discover the ideal concentration of Advanced Platelet Rich Fibrin (A-PRF) as modification of PRF, for human Dental Pulp Stem Cells (hDPSCs) differentiation. Material and Methods: hDPSCs were devided into five experimental groups: Group I (control group) consist of hDPSCs cultured in 10% FBS, Group II consist of hDPSCs cultured in 1% A-PRF, Group III consist of hDPSCs cultured in 5% A-PRF, Group IV consist of hDPSCs cultured in 10% A-PRF and Group V consist of hDPSCs cultured in 25% A-APRF. All group have been observed for 7 and 14 days and each group had three biological replicates (triplo). Formation of the mineralized nodules was detected after 7 days by Alizarin red-based assay and Dentin Sialophosphoprotein (DSPP) expression after 7 and 14 days quantified by ELISA reader. Statistical analysis was proven with Kruskal-Wallis and post hoc Mann-Whitney test Results: The differentiation of hDPSCs in all A-PRF groups was significantly different on day-7 (p<0.05) compare to control group (Group I). There were no significant differences between all groups on day-14 (p>0.05). Significantly differences between Group II (1% A-PRF) and Group I (control), Group II (1% A-PRF) and Group III (5% A-PRF), also Group II (1% A-PRF) and Group V (25% A-PRF) was found from post hoc test analysis Conclusion: The ideal conditioned media concentration for differentiation of human dental pulp stem cells was on 1% up to 5% A-PRF group.

Accuracy of visual and image-based ICDAS criteria compared with a micro-CT gold standard for caries detection on occlusal surfaces

Abstract The aim of this study was to check the in vitro accuracy of ICDAS criteria on digital images compared to visual examination for the diagnosis of occlusal caries against a micro-CT gold standard. ICDAS was scored in 40 extracted permanent molars by means of visual inspection and stereomicroscopic images. Visual examinations were performed in duplicate and at a one-week interval by three different calibrated examiners. The analysis of digital images by ICDAS criteria was also performed in duplicate, 1 month after visual examinations. The detection methods were compared by means of sensitivity, specificity, area under the curve, predictive positive and negative values, and accuracy for two different thresholds (1- sound vs. carious teeth; 2- tooth requiring operative vs. non-operative treatment). Sensitivity and accuracy values for threshold 1 in the visual ICDAS and image-based ICDAS methods were high for sensitivity (0.93 and 0.97) and for accuracy (0.83 and 0.85), but low for specificity (0.55 for both methods). Specificity values for threshold 2 were 0.77 and 0.82, while sensitivity was 0.33 and 0.28 for each method. Spearman's rank correlation coefficient was 0.53 and 0.43 (p<0.05) for visual and image-based ICDAS compared to the gold standard scores. Both visual and image-based ICDAS scores were similar to each other in terms of diagnostic accuracy when compared to the micro-CT gold standard. Low specificity for the presence of caries and sensitivity for the detection of caries requiring operative treatment were found.

Pulp analysis of teeth submitted to different types of forces: a histological study in rats

Abstract Objective: The purpose of this study was to histologically evaluate pulp and dentin under induced tooth movement (ITM) with different types of forces. Material and Methods: The maxillary right first molars of rats were submitted to movement with continuous (CF), continuous interrupted (CIF) and intermittent (IF) forces during 5, 7 and 9 days with nickel-titanium (NiTi) closed-coil springs exerting 50cN force magnitude. The groups were histologically evaluated as for cellularity pattern, presence of dystrophic, hemodynamic alterations in the pulp as well dentin alterations. The main observed alterations were related to hemodynamic pulp characteristics, such as presence of thrombosis, vascular congestion and hemorrhages. The hemodynamic alterations were statistically evaluated by Shapiro-Wilk normality test and analysis of variance by the Kruskall-Wallis test. Results: There was no significant differences observed between groups in the different types of applied forces and duration of ITM (vascular congestion, p=1.000; hemorrhage, p=0.305; thrombosis, p=1.000). Conclusions: Pulp tissue alterations resulting from ITM were limited to hemodynamic events, without progressing to irreversible degeneration, regardless of the type of force applied.

How biomechanics can affect the endodontic treated teeth and their restorative procedures?

Abstract: Endodontic treatment is a common dental procedure used for treating teeth which the pulp tissue has become irreversibly inflamed or necrotic as a result of the carious process or dental trauma. This procedure which involves mechanical and chemical preparation of root canal may affect several mechanical and physical properties of the tooth structure. The endodontic treatment can also influence the longevity of the rehabilitation of endodontically treated teeth and biomechanics during the oral function. For restoring endodontically treated teeth several factor and clinical decisions should be observed. The decision of the fiberglass post usage and the restorative materials are related to several factors such as the quantity and quality of remaining dental structure, presence of ferrule, post cementation length and final coronal restoration. In this review, the authors will address the effect of the endodontic treatment procedures on canal shape and mechanical properties of a tooth, and also discuss the parameters and the biomechanical principles of root canal treated teeth.

Effect of a Bioactive Glass Ceramic on the Control of Enamel and Dentin Erosion Lesions

Abstract This study evaluated the effect of a bioactive glass ceramic for the control of erosion and caries lesions. Fragments (n=10) of bovine enamel and root dentin received daily application of different treatments (Biosilicate; Acidulated Phosphate Fluoride- APF; Untreated - control) during the performance of erosive cycles. Surfaces were analyzed with 3D optical profilometry to quantify the superficial loss in four periods (1, 7, 14 and 21 days), as well as the lesion depth with confocal laser scanning microscopy. For caries progression assessment, initial Knoop microhardness was measured on enamel bovine fragments. Initial carious lesions were developed and specimens were divided into three groups (n=10), according to the daily topical application (Biosilicate; APF; no application - control), during the de-remineralization cycles for 14 days. Final microhardness was obtained to calculate the change of surface microhardness. Subsurface demineralization was analyzed using cross-sectional microhardness (depths 10, 30, 50, 70, 90, 110 and 220 µm). Data were tested using ANOVA and Tukey's test (a=5%). Results of erosive evaluation showed that Biosilicate promoted the lowest (p<0.05) values of surface loss, regardless of time, for both enamel and dentin; APF promoted lower (p<0.05) surface loss than control; analyzing different periods of time, APF did not show difference (p>0.05) between 14 and 21 days of demineralization. Results of enamel caries assessment showed that Biosilicate resulted in higher (p<0.05) surface and subsurface microhardness than both APF and control-applications. It may be concluded that Biosilicate application showed a higher potential to reduce surface loss and development of erosion and caries lesions.

Resumo Este estudo avaliou o efeito de uma vitrocerâmica bioativa para o controle de lesões de erosão e cárie. Fragmentos (n=10) de esmalte bovino e dentina radicular receberam aplicação diária de diferentes tratamentos (Biosilicato; Fluoreto de Fosfato Acidulado - APF; não tratado - controle) durante a realização de ciclos erosivos. As superfícies foram analisadas com profilometria óptica 3D para quantificar a perda superficial em quatro períodos (1, 7, 14 e 21 dias), bem como a profundidade da lesão com microscopia confocal de varredura a laser. Para a avaliação da progressão de cárie, foi obtida a microdureza Knoop inicial de fragmentos de esmalte bovino. As lesões cariosas iniciais foram desenvolvidas e os espécimes foram divididos em três grupos (n =10), de acordo com a aplicação tópica diária (Biosilicato; APF; sem aplicação - controle) durante os ciclos de desmineralização por 14 dias. A microdureza final foi obtida para calcular a perda da microdureza superficial. A desmineralização sub-superficial foi analisada utilizando microdureza transversal (profundidades 10, 30, 50, 70, 90, 110 e 220 μm). Os dados foram testados utilizando ANOVA e teste de Tukey (α=5%). Os resultados da avaliação erosiva mostraram que o Biosilicato promoveu os menores valores (p <0,05) de perda superficial, independente do tempo, tanto para o esmalte como para a dentina; APF promoveu menor (p <0,05) perda de superfície do que controle; analisando os períodos de tempo, APF não mostrou diferença (p>0,05) entre 14 e 21 dias de desmineralização. Os resultados da avaliação da cárie no esmalte mostraram que o Biosilicato resultou em maiores (p<0,05) valores de microdureza superficial e subsuperficial do que as aplicações APF e controle. Pode-se concluir que a aplicação de Biosilicato apresentou maior potencial de redução da perda superficial e desenvolvimento de lesões de erosão e cárie.

Validation of micro-computed tomography for occlusal caries detection: an in vitro study

Conventional methods of caries detection, including the gold standard of histological examination, have certain disadvantages that must be addressed prior to validating any other diagnostic technique—current or new. Here we evaluated the validity of micro-computed tomography (micro-CT) as an alternative gold-standard technique for caries detection. Sixty teeth with suspected occlusal caries were chosen from a pool of teeth extracted for orthodontic, periodontal, or surgical reasons. Identical reference points were marked on photographs taken for teeth and were used to evaluate each method. Dimensions of caries were assessed by two calibrated examiners using the ICDAS-II visual examination system, bitewing radiographs, and micro-CT. The teeth included in the study were selected randomly from solution before all measurements. For micro-CT, the device was set to 50 kV, 800 µA, pixel size 15 µm (at 1024 × 1024 resolution), and 1° rotation step. NRecon software (SkyScan) was used to obtain reconstructed images. For each diagnostic method, results were compared with histology results using the McNemar test. Receiver operator characteristic (ROC) analysis was also performed for each method (Z-test; p < 0.05). Besides showing a high correlation with histology results, micro-CT yielded the greatest values at the D3 threshold; moreover, accuracy and area under the ROC curve (AUC) values were greatest at the D1threshold. Our results indicate that micro-CT performs as well as or better than histological examination for the purpose of comparing methods for caries detection.

Microscopic evaluation of induced tooth movement after subluxation trauma: an experimental study in rats

OBJECTIVE: The objective of this study was to assess the histological alterations that occurred in the periodontal area of rat molars submitted to induced tooth movement (ITM) right after an intentional trauma (subluxation). METHODS: Forty adult male Wistar rats (Rattus norvegicus albinus) were selected. The animals were divided into eight groups (n = 5), according to the combination of variables: Group 1 - control (neither trauma nor ITM); Group 2 - ITM; Groups 3, 4, 5 and 6 - dentoalveolar trauma groups corresponding, respectively, to 1, 3, 8 and 10 days after trauma; Groups 7 and 8 - the animals' molars were subjected to a 900 cN impact and, one and three days after the trauma event, tooth movement was induced. The rats' maxillary first molars were mesially moved during seven days with a closed coil (50 cN). After the experimental period of each group, the animals were sacrificed by anesthetic overdose and the right maxillas were removed and processed for histological analysis under light microscopy. RESULTS: In the animals of group 3, 4, 5 and 6, the histological alterations were not very significant. Consequently, the effect of induced tooth movement right after a subluxation event (groups 7 and 8) was very similar to those described for Group 2. CONCLUSION: There was no difference in the quality of periodontal repair when ITM was applied to teeth that had suffered a subluxation trauma. .

OBJETIVO: avaliar as alterações histológicas ocorridas na área periodontal de molares de ratos submetidos à movimentação dentária induzida (MDI), logo após um trauma intencional (subluxação). MÉTODOS: quarenta ratos Wistar machos adultos (Rattus norvegicus albinus) foram selecionados. Os animais foram divididos em oito grupos (n = 5), de acordo com a combinação das variáveis: Grupo 1 - controle (sem trauma e sem MDI); Grupo 2 - MDI; Grupos 3, 4, 5 e 6 - grupos de trauma dentoalveolar correspondendo, respectivamente, para 1, 3, 8 e 10 dias após o trauma; Grupos 7 e 8 - os molares murinos foram submetidos a um impacto de 900cN e, de um e três dias após o evento trauma, o movimento do dente foi induzido. Os primeiros molares superiores dos animais foram movidos mesialmente durante sete dias, com uma mola fechada (50cN). Após período experimental de cada grupo, os animais foram sacrificados por overdose anestésica e as maxilas direitas foram removidas e processadas para análise histológica qualitativa. RESULTADOS: nos animais dos grupos 3, 4, 5 e 6, as alterações histológicas não foram muito significativas. Consequentemente, o efeito do movimento dentário induzido logo após um evento de subluxação (grupos 7 e 8) foi muito semelhante ao descrito para o grupo 2. CONCLUSÃO: não houve diferença na qualidade do reparo periodontal quando a MDI foi aplicada aos dentes que sofreram um trauma de subluxação. .

Molecular and Structural Evaluation of Dentin Caries-Like Lesions Produced by Different Artificial Models

This study evaluated structural and molecular issues of dentin caries-like lesions produced by different artificial models (ACL) compared with natural caries lesions (NCL). One hundred twenty-four sound occlusal dentin blocks and 47 carious blocks were obtained and surface hardness was analyzed (SH1). They were assigned to groups according to ACL: GB: Biological; GC: Chemical; GIS: In situ; GNC: natural caries (control). Blocks from groups 1, 2 and 3 were submitted to caries lesion induction. NCL and ACL blocks were submitted to surface hardness (SH 2), FT-Raman and µEDXRF analysis. All blocks were longitudinally sectioned and one of the halves was submitted to cross-sectional hardness (CSH) and the other to SEM analysis. SH1 and SH2 data were submitted to t test (unpaired and paired, respectively), CSH and SEM data to two-way and one-way ANOVA respectively, and Tukey and t tests, respectively (p<0.05). Data from FT-Raman/µEDXRF were submitted to one-way ANOVA and Dunnett multiple-comparisons test (a=0.05). GB and GNC showed lowest SH2 values that were significantly different from GC and GIS. Regarding CSH, GB and GNC showed no significant difference between them. SEM showed similar caries lesion depth for GB and GNC, being significantly higher than for GC and GIS. µEDXRF showed similar values of calcium and phosphate for GB and GNC; GNC values were significantly different from GIS. No significant difference was found among the groups concerning phosphate, carbonate and CH bonds values. For collagen type I, GC values were significantly different compared to other groups. It may be concluded that caries-like lesions produced by GB were the closest model to NCL.

Este estudo avaliou as características estruturais e moleculares da lesão de cárie artificial em dentina produzidas por diferentes modelos artificiais (LCA) comparados à lesão de cárie natural (LCN). Cento e vinte e quatro blocos de dentina oclusal hígida e 47 blocos cariados foram obtidos e a dureza superficial foi analisada (SH1). Eles foram divididos em grupos de acordo com os modelos de LCA: GB: Biológico; GQ: Químico; GIS: In situ; GCN: lesão de cárie natural (controle). Blocos dos grupos 1, 2 e 3 foram submetidos à produção da lesão de cárie. Blocos de dente contendo LCA e LCN foram submetidos à análise de dureza superficial (SH2), análise FT-Raman e µEDXRF. Em seguida, todos os blocos foram seccionados longitudinalmente e uma das metades foi submetida à análise da dureza transversal (CSH) e outra à análise em microscopia eletrônica de varredura (MEV). Dados da SH1 e SH2 foram submetidos ao teste t (não-pareado e pareado, respectivamente). Dados do CSH e MEV foram submetidos à ANOVA a um fator e teste Tukey e ANOVA a um fator e teste t, respectivamente (p<0,05). Dados do FT-raman/µEDXRF foram submetidos a ANOVA a um fator e teste de Dunnett para múltiplas comparações (p<0,05). GB e GCN apresentaram os menores valores de SH2 que foram significativamente diferentes de GC e GIS. Quanto a CSH, GB e GCN mostraram nenhuma diferença significativa entre eles. SEM mostrou profundidade de lesão de cárie semelhante para GB e GCN, sendo significativamente maior que para GC e GIS. µEDXRF mostrou valores similares de cálcio e fosfato para GB e GCN, enquanto os valores do GCN foram significativamente diferentes em relação ao GIS. Nenhuma diferença significativa foi encontrada entre os grupos em relação aos valores de fosfato, carbonato e ligações CH. Para o colágeno tipo I, os valores do GC foram significativamente diferentes em comparação aos outros grupos. Pode-se concluir que a cárie artificial produzida pelo GB foi o mais próximo da LCN.

Apical Barrier Formation After Incomplete Orthograde MTA Apical Plug Placement in Teeth with Open Apex - Report of Two Cases

Two cases are reported in which incomplete placement of 4 mm mineral trioxide aggregate (MTA) plug was performed unintentionally at the apical third of permanent immature teeth with open apex and apical periodontitis. As confirmed radiographically, there were gaps between MTA and dentinal walls along the MTA-dentin interface. After setting of MTA was confirmed, endodontic treatment was completed and access was sealed with composite resin. At 6 to 16 months follow-up examinations, formation of dentin in contact with the MTA surface, as well as apical closure and periapical healing were ideied radiographically for both cases. The results of these cases showed that apical barrier formation and complete periapical healing is possible despite the incomplete apical placement of the MTA plug. This might be due to the biological properties of the MTA. Even so, an incomplete three-dimensional placement of the filling material is not advocated.

Influencia del método de remoción de caries en la fuerza de adhesión a dentina afectada / Influence of caries removal method on bond strength to dentin affected

La técnica de adhesión en dentina es una técnica poco predecible y se agudiza aun más cuando la dentina ha sido afectada por caries ya que las alteraciones histológicas disminuyen la posibilidad de esta unión; no obstante la variación en la técnica de remoción del tejido cariado pudiera influir de manera independiente en la unión. El objetivo de esta investigación es determinar la influencia del método de remoción del tejido cariado en la resistencia adhesiva en micro tracción (µTBS) de resina compuesta unida a dentina humana afectada por caries. Se utilizaron 15 molares humanos afectados por caries y de manera aleatoria simple se dividieron en tres grupos (G1,G2,G3), luego se realizó un corte con disco de diamante (KG Sorensen® /Brasil) perpendicular al eje mayor del diente exponiendo la mayor cantidad de dentina afectada, el G1 fue sometido a remoción con Aire abrasivo de oxido de aluminio de 50 µm a una presión de 40 PSI (Microjato®, Bio-art /Brasil), al G2 se le eliminó la caries con fresa redonda de carburo N° 6 a baja velocidad (KG Sorensen® /Brasil)y al G3 se le eliminó con el método Químico/Mecánico (PAPACARIE ® /Brasil y Cucharita para dentina), la eliminación fue corroborada con fluorescencia laser (DIAGNOdent®, Kavo /Germany), posteriormente se aplicó la técnica de grabado total siguiendo las indicaciones del fabricante para adhesivo Excite ®( Ivoclar Vivadent Inc. /USA), y se restauraron 6 mm oclusales con resina compuesta Brilliant Enamel New Line® (Coltène-Whaledent /Germany.), luego se seccionaron con una sierra de precisión ISOMET 1000® (Buehler /USA) y se obtuvieron muestras de 1x1x10 mm , a continuación las muestras se prepararon para la prueba de micro tracción en la máquina de prueba universales AGS-J (Shimadzu /Japan) a una velocidad de desplazamiento de 0,5mm por min. Los datos fueron recolectados en hoja de cálculo Excel y analizados con un ANOVA de 1 Vía, en un nivel (µBts), el valor de p quedo preestablecido en p?0,05

The dentin adhesion technique is a quite unpredictable one and it is enhanced when the dentin has been affected because histological alterations reduce the chance for this union; however, the variation in the removal technique of caries-affected tissue could have an independent influence on the union. Aim: to determine the influence of the method of caries-affected tissue removal on the adhesive resistance in micro-tensile (µTBS) of composite bonded to human dentin affected by caries. Methods: 15 human molars affected by caries were randomly assigned into three groups (G1, G2, and G3). Then, one cut with a diamond disc (KG Sorensen® /Brasil) was performed perpendicular to the major axis of the teeth exposing the larger amount on affected dentin. G1 condition was removal with abrasive air of aluminum oxide of 50 µm at a 40 PSI (Microjato®, Bio-art /Brasil) pressure. G2 had caries removal with carbide round drill N° 6 at a low speed (KG Sorensen® /Brasil). Finally, for G3 caries was removed with the Chemical/Mechanical method (PAPACARIE ® /Brasil and spoon excavator). The elimination was corroborated by laser fluorescence (DIAGNODENT®, Kavo /Germany); later, the total etching technique was performed by following the manufacturer instructions for Excite ® (Ivoclar Vivadent Inc. /USA) and 6 oclusal mm were restored with composite Brilliant Enamel New Line® (Coltène-Whaledent /Germany.), then they were cut with a precision saw ISOMET 1000® (Buehler /USA) and 1x1x10 mm samples were obtained. The samples were prepared for the micro traction test in the universal testing machine AGS-J (Shimadzu /Japan) a speed of 0,5mm per minute. Data were recorded in Microsoft Excel and a one way ANOVA was performed for one level (µBts), the p value was established at p?0,05. Results: the mean µBts in MPa for each group and the standard deviation (±SD) was as follows: G1= 21,7 (8,6) G2=19,70 (10,5) G3=22,2 (9,7)

Use of glass ionomer cement containing antibiotics to seal off infected dentin: a randomized clinical trial

Dental materials with antibacterial properties can prevent the harmful effects caused by oral cariogenic bacteria. This double-blind controlled clinical trial evaluated the performance of a glass ionomer cement (GIC) added with antibiotics for sealing infected dentin in atraumatic restorations of primary molars. The study enrolled 45 children (45 teeth) between 5 and 8 years of age, of both genders, divided into two groups: GC (n=22), where cavities were lined with a conventional GIC (Vidrion F) and GA (n=23), with cavities lined with Vidrion F added with 1% each of metronidazole, ciprofloxacin and cefaclor antibiotic. Both groups were restored with Ketac Molar Easymix. Molars with carious lesions on the inner half of dentin without clinical or radiographic pulp damage were selected. Patients were evaluated clinically (pain, fistulas or mobility) and radiographically (area of caries, periapical region and furcation) after 1, 3, 6 and 12 months. For statistical analysis, chi-squared or Fisher's exact tests were used with a 5% significance level. GA (82.6-95.7%) had better results than GC (12.5-36.4%) in all evaluations (p<0.05) and the difference in the success rate was 46.2-72.5% higher for GA. The use of the antibiotic-containing GIC liner on infected dentin proved satisfactory when applied in deciduous teeth.

Os materiais dentários com propriedades antibacterianas podem proteger os efeitos nocivos causados por bactérias cariogênicas. Este ensaio clínico controlado duplo-cego avaliou o desempenho do cimento de ionômero de vidro (CIV) associado à antibióticos no selamento da dentina infectada em restaurações atraumáticas de molares decíduos. O estudo envolveu 45 crianças (45 dentes) entre 5 e 8 anos de idade, de ambos os sexos, divididos em dois grupos: GC (n=22), onde as cavidades foram forradas com CIV convencional (Vidrion F) e GA (n=23), onde as cavidades foram forradas com Vidrion F contendo 1% de cada um dos antibióticos metronidazole, ciprofloxacina e cefaclor. Ambos os grupos foram restaurados com Ketac Molar Easymix. Molares com lesões de cárie na metade interna da dentina, sem danos pulpares clínicos ou radiográficos foram selecionados. Os pacientes foram avaliados clinicamente (presença de dor, fístulas ou mobilidade) e radiograficamente (área de cárie, região periapical e de furca dos dentes), após 1, 3, 6 e 12 meses. Para a análise estatística o Qui-quadrado ou Exato de Fisher foram utilizados com 5,0% de significância. GA (82,6-95,7%) obteve melhores resultados do que GC (12,5-36,4%) em todas as avaliações (p<0,05) e a diferença na taxa de sucesso foi de 46,2-72,5% maior para GA. O uso do CIV com antibióticos no forramento da dentina infectada foi satisfatório em dentes decíduos.

Uso de trióxido mineral agregado (MTA) en el tratamiento de una reabsorción cemento-dentinaria externa: caso clínico / The use of mineral trioxide aggregate (MTA) in external root resorption treatment: a clinical case

Objetivos: se describe el tratamiento de una pieza dentaria que presenta reabsorción cemento-dentinaria externa (RCDE) como consecuencia de un traumatismo ocurrido hace veinticinco años. Caso clínico: la resolución se completó en dos etapas. En la primera, dado que se observó una obturación incorrecta, se realizó el retratamiento endodóntico y se obturó con conos de gutapercha y sellador Sealer 26. En la sesión siguiente, se levantó un colgajo con el objetivo de exponer y explorar la zona radiolúcida presente en distal de la raíz a la altura del tercio medio. Se realizó un curetaje y se rellenó la cavidad de la reabsorción con trióxido mineral blanco (MTA). La rehabilitación estética de la corona fue realizada con una carilla de composite a mano alzada. Después de dos años de haber realizado el tratamiento y en controles radiográficos periódicos, se observó que la RCDE se detuvo. Conclusión: las reabsorciones cemento-dentinarias externas inflamatorias son lesiones relativamente frecuentes luego de un traumatismo dentario. Es importante realizar un diagnóstico temprano para evitar su evolución y la consecuente pérdida de la pieza. El material fue elegido teniendo en cuenta sus propiedades físicas y químicas, entre las que se destacan su baja citotoxicidad, la capacidad de solidificar en presencia de humedad y el estímulo que ejerce sobre la regeneración del ligamento periodontal.

Selamento imediato da dentina na otimização de coroas de cerâmicas puras / Immediate dentin sealing in pure ceramic crowns optimization

Na técnica convencional de cimentação em prótese fixa, o adesivo é aplicado e/ou fotopolimerizado somente na fase de cimentação da peça. Caso a dentina seja contaminada anteriormente, esta adesão é prejudicada. A dentina recém-preparada é considerada o substrato ideal para a adesão, pois não há risco de contaminação. Com base nessa ideia, tem sido sugerido que logo após o preparo e antes da moldagem, o mesmo seja selado com um adesivo dentinário. Esta técnica é denominada Selamento Imediato da Dentina (SID) e possui várias vantagens em relação à técnica convencional de cimentação. O objetivo deste trabalho é descrever e discutir esta técnica de aplicação clínica que contribui para o aumento da resistência e ajuda a evitar a sensibilidade dentária

In indirect restorations conventional luting, the adhesive is applied and/or light cured during the luting procedure, after provisional phase. If dentin is infected previously, this adhesion is impaired. The freshly cut dentin is considered the ideal substrate for dentin bonding, because there is no risk of contamination. Based on this idea, it has been suggested that after exposing dentin, it must be sealed with a dentin adhesive. This technique is called Immediate Dentin Sealing (IDS) and has several advantages over the conventional luting. The aim of this study is describe and discuss this clinical technique that contributes to increase dentin bond strength and prevents tooth sensitivity

A finite element thermal analysis of various dowel and core materials.

Aim: Thermal analysis of the temperature and stress distribution of parallel sided, threaded and non-threaded dowels and core materials under thermal loading within a maxillary central incisor using a three dimensional finite element study. Materials and Methods: 3D models of endodontically treated maxillary central incisor with parallel sided, threaded and non- threaded post and core materials were simulated using the ANSYS software. Materials simulated were parallel sided cast gold post and core, parallel sided fibre reinforced composite (FRC) post and core, and parallel sided, threaded, prefabricated stainless steel post and amalgam core. Thermal loads simulating hot (60 degree C/ 333K) and cold (15 degree C/288K) liquid were applied for 15 seconds at the incisal edge. The temperature changes at the selected nodes were obtained on the various post and core materials, interface between post and dentin, interface between core and dentin, within the dentin and within the cement layer. Results: Temperature and stress distribution pattern were represented in numerical and color coding and results interpreted. Thermal stresses arises as a result of temperature changes. A decreased temperature gradient of the metallic dowels and core (T1 hot - 0.002K, T3 hot - 1.071K, T1 cold -0.99K, T3 cold - 0K) were obtained than that of the FRC dowel and core of 1.982K(hot) and1.55K(cold) respectively due to the higher thermal conductivity of the metals. Higher thermal stress values of 3.567 Mpa(hot) and 3.092 Mpa(cold) respectively were obtained for the FRC dowels and higher stress values of 39.679 Mpa(hot) and 57.855 Mpa(cold) respectively were also obtained for the FRC cores. These values indicated that thermal stresses of the FRC dowel and core were greater than that of cast gold dowel and core and prefabricated stainless steel dowel and amalgam core due to its high coefficient of thermal expansion. Maximum stress values of the FRC dowel and core of 1.87 Mpa(hot) and 2.57 Mpa(cold) respectively were also generated in the cement layer, core and metal ceramic crown. The junction of the metal ceramic crown and dentin demonstrated the maximum stress. Higher thermal stress values of 59.162 ± 10 Mpa were obtained in the restoration and the coronal portion of the dentin than the stress levels of .0039 ± 10Mpa in the supporting bone due to an increased thermal expansion. Conclusion: Non-metallic dowel and core materials such as fibre reinforced composite dowels (FRC) generate greater stress than metallic dowel and core materials. This emphasized the preferable use of the metallic dowel and core materials in the oral environment.

In Vitro assessment of dentin erosion after immersion in acidic beverages: surface profile analysis and energy-dispersive X-ray fluorescence spectrometry study

The aim of this study was to investigate the effects of some acidic drinks on dentin erosion, using methods of surface profile (SP) analysis and energy-dispersive X-ray fluorescence spectrometry (EDXRF). One hundred standardized dentin slabs obtained from bovine incisor roots were used. Dentin slabs measuring 5x5 mm were ground flat, polished and half of each specimen surface was protected with nail polish. For 60 min, the dentin surfaces were immersed in 50 mL of 5 different drinks (Gatorade®, Del Valle Mais orange juice®, Coca-Cola®, Red Bull® and white wine), 20 blocks in each drink. The pH of each beverage was measured. After the erosive challenge, the nail polish was removed and SP was analyzed. The mineral concentration of dentin surfaces was determined by means of EDXRF. Data were analyzed statistically by ANOVA and Tukey's test (α=0.05). SP analysis showed that Red-Bull had the highest erosive potential (p<0.05). EDXRF results exhibited a decrease in phosphate in the groups immersed in Red-Bull, orange juice and white wine (p<0.05), and no significant difference in calcium content between the reference surface and eroded surface. In conclusion, this study demonstrated that all studied beverages promoted erosion on root dentin and Red Bull had the highest erosive potential. There was no correlation between pH of beverages and their erosive potential and only the P content changed after erosive challenge.

O objetivo deste estudo foi investigar os efeitos de algumas bebidas ácidas sobre a erosão da dentina, utilizando métodos de análise de perfil de superfície (SP) e espectrometria de energia dispersiva de fluorescência de raios X (EDXRF). Cem blocos de dentina padronizados obtidos de raízes de incisivos bovinos foram utilizados. Os blocos de dentina medindo 5x5 mm foram planificados, polidos e metade de cada superfície das amostras foram impermeabilizados com esmalte para unhas. Por 60 min, as superfícies de dentina foram imersas em 50 mL de 5 bebidas diferentes (Gatorade, suco de laranja, Coca-Cola, Red Bull e vinho branco), 20 blocos em cada bebida. O pH de cada bebida foi medido. Após o desafio erosivo, o esmalte de unha foi removido e SP foram analisados. A concentração de minerais das superfícies de dentina foi determinada por meio de EDXRF. Os dados foram analisados estatisticamente por ANOVA e teste de Tukey. (p<0,05). A análise SP mostrou que o Red-Bull apresentou o maior potencial erosivo. Os resultados do EDXRF apresentaram uma diminuição do fosfato dos grupos imersos no Red-Bull, suco de laranja e vinho branco, e não houve diferença significativa no teor de cálcio entre a superfície de referência e a superfície que sofreu erosão. O Red Bull apresentou o maior potencial erosivo sobre a dentina radicular. Não houve correlação entre o pH das bebidas e o seu potencial erosivo.

Efecto del grabado de la dentina radicular con ácido dietilenoaminotetra acético (EDTA) en la resistencia de unión de cementos autoadhesivos y autograbantes / Effect of engraving dietilenoaminotetra acetic acid (EDTA) root dentin in the resistance of cemented joints stickers and etching

Fue evaluado el efecto del grabado de la dentina radicular con EDTA en la resistencia de unión (RU) inmediata (IM) y después de termociclaje (TM) de un cemento autoadhesivo (AA) y uno auto grabador (AG) para la cementación de postes de fibra de vidrio. Fueron utilizadas 40 raíces de premolares humanos divididas en 4 grupos según tipo de cementación (n=10) G1 RelyX U100 (UC) según indicaciones del fabricante(IF); G2 grabado con EDTA 24% por 60 s antes de la aplicación del UC ; G3 Para Post Para Core Automix (PC) (IF)G4 - grabado con EDTA 24% por 60 s antes de la aplicación del (PC).Las raíces fueron cortadas en discos de 1 mm (dos discos por tercio radicular), la mitad de los discos fueron sometidos a ensayo expulsión IM (0,5mm/min) y la otra mitad después de TM (5º C e 55º C).los datos fueron analizados en test de ANOVA y Tukey (?=0,05).dando como resultado que el grabado con EDTA altero negativamente los valores de RU solo del tercio cervical en los dos cementos. Cuando fue comparado TM con IM con o sin aplicación de EDTA no se encontraron diferencias estadísticas significativas. Para todos los grupos testados.El cemento PC obtuvo mayores valores de RU (19,59 MPa) comparado con el UC (15,80 MPa).concluyéndose que el tratamiento con EDTA afecto la RU solo para el tercio cervical tanto en IM como TM en los dos cementos. El TM con o sin EDTA no afecto los valores de RU cuando comparado con IM

The effect of post-space treatment whit EDTA on the bond strength (BS) of fiber posts in different root regions was evaluated using two different type of resin cements Rely X U100 (UC) and Para Post Para Core automix (PC) . Fourty extracted premolars root canals were assigned to four groups of 10 roots each. G1 RelyX U100 (UC) according to manufacturer's instructions (MI), G2 etching whit EDTA 24% for 60 s before application of UC; G3 Para Post Para Core Automix (PC) MI; G4 Etching whit EDTA 24% for 60s before application off PC. After cementation the roots were sectioned in 6 slices 1mm each (two slides for root region) and randomly divided into two subgroups, depending on testing time immediate (IM) vs. after termocicling(TM) ), for expulsion test. Statistical analysis was performed with ANOVA and Tukey test (?=.05) No differences in BS was found among the groups whit and whit out EDTA 24 %. Etching whit EDTA adversely alter the BS values of the cervical third in the two cements. When TM was compared with IM with or without application of EDTA there was no statistically significant difference. For all groups tested, PC show higher values of BS (19.59 MPa) was compared with UC (15.80 MPa). Concluded that treatment with EDTA affected the BS only on the cervical third in both IM and TM in the two cements. The TM with or without EDTA did not affect the values of BS when compared with IM