Protocolo para diafanización dental / Protocol for dental diafanization

Antecedentes: La Diafanización dental es una técnica que permite transparentar los dientes haciendo visible la anatomía interna de los conductos radiculares ofreciendo una herramienta pedagógica económica y confiable; sin embargo, la literatura no reporta protocolos estandarizados para obtener una diafanización dental predecible. Objetivo: Obtener un protocolo estandarizado para diafanización dental, como modelo educativo, a partir de la revisión de la literatura y la realización de un estudio piloto. Materiales y Métodos: Se realizó una búsqueda sistemática en las bases de datos Scopus y Medline con los términos Mesh "root canal", "diaphonization", "clearing", "morphology" anatomy", y se estructuró una tabla de extracción con las variables más representativas para establecer las 3 fases de la Diafanización, a. Descalcificación, se evaluó Ácido Nítrico 5% (HNO3), Ácido Fórmico 10% (CH2O2) y EDTA 10%, b. Deshidratación, se empleó Alcoholes etílicos ascendentes, c. Clarificación, se evaluó Metil Salicilato y Aceite de Inmersión Sintético. Se seleccionaron 54 dientes, 36 sin endodoncia, y 18 con endodoncia, y se distribuyeron en dos grupos: Grupo A. Dientes sin endodoncia, Grupo B. Dientes con endodoncia, constituidos por 18 subgrupos que estaban definidos de acuerdo al tipo de descalcificante, momento de aplicación medio de contraste y medio de Clarificación. Resultados: El Ácido Nítrico al 5% pese a que fue el más corrosivo, permitió el mayor flujo y accesibilidad para el medio de contraste (Tinta China) en especímenes sin endodoncia. De igual manera, el Ácido Fórmico al 10%, preservó la estructura de los dientes tratados endodónticamente. El Metil Salicilato como clarificante, brindó mejores resultados visuales alcanzando una mayor transparencia. Conclusiones: El desarrollo de un estudio piloto para estandarizar técnicas de diafanización en odontología, permite la estructuración de un protocolo educativo que posibilita conocer la gran variabilidad anatómica de los dientes y la comprensión y análisis de los dientes que han si do tratados endodóncicamente, aportando una herramienta pedagógica para la comprensión de la anatomía radicular. El uso de Ácido Fórmico al 10%, en dientes con tratamiento de endodoncia y de Ácido Nítrico 5% en dientes sin endodoncia, c on una transparencia alcanzada por el uso del Metil Salicilato, muestran los mejores resultados visuales en anatomía y obturación endodóntica.

Background: Dental diaphonization is a technique that allows the teeth to be made transparent, making the internal anatomy of the root canals visible, offering an economical and reliable pedagogical tool; however,the literature does not report standardized protocols to obtain a predictable dental clearance. Aim: obtain a standardized protocol for dental diaphonization as an educative model from the review of the literature and the realization of a pilot study. Materials and methods: A systematic search was made on databases Scopus and Medline, with the Mesh terms "root canal", "diaphonization", "clearing", "morphology" and, "anatomy", and an extraction table was structured wit h the most representative variables to establish the three diaphanization phases, a. Decalcification, 5% Nitric Acid, 10% Formic Acid (TBD-2) and 10% EDTA were evaluated, b. Dehydration, ascending Ethyl Alcohols were used, c. Clarification, Methyl Salicylate, a nd Immersion synthetic oil were evaluated. 54 teeth were selected, 36 without root canal treatment and 18 with root canal treatment, then they were distributed into two groups: Group A, Teeth without root canal treatment, and Group B, Teeth with root canal treatment. Each group was constituted of 18 subgroups defined in order of the decalcification agent type, moment of the contrast medium application, and clarification agent type. Results: Even though 5% Nitric Acid was the most corrosive agent, it allowed a better flow and accessibility for the contrast medium (Chinese ink) in teeth without root canal treatment. Likewise, 10% Formic Acid preserved the structure of the endodontic tooth. As a clarification agent, the Methyl Salicylate showed better visual results, achieving greater transparency. Conclusion: The development of a pilot study aimed to standardize diaphonization techniques in dentistry allows the structuring of educative protocols that permit knowing the great tooth anatomic variability and the comprehension as well as the analysis of the root canal treated teeth, contributing to a pedagogic tool for the root anatomy awareness. Using 10% Formic Acid on root canal-treated teeth and 5% Nitric Acid on root canal not treated teeth, with transparency achieved by using Methyl Salicylate, showed better visual results on anatomy and endodontic filling

Evaluación radiográfica de la frecuencia y distribución de los nódulos pulpares / Radiographic evaluation of the frequency and distribution of pulp nodules

Objetivos: Estimar la prevalencia de nódulos pulpares y agujas cálcicas en pacientes atendidos en la Cátedra de Endodoncia, Facultad de Odontología, Universidad de Buenos Aires (CEFOUBA). Se analizaron radiografías de 1866 piezas dentarias, con ápices maduros, de pacientes de ambos géneros, mayores de 15 años, tratados en CEFOUBA, en el período comprendido entre junio-noviembre de 2018. Género, edad, grupo dentario, condición del diente, presencia de patología sistémica, y ubicación anatómica, fueron las variables registradas. Se calcularon intervalos de confianza 95%, método score de Wilson. Se utilizó test z para diferencias de proporciones. El porcentaje de piezas con calcificaciones superó significativamente a piezas sin calcificaciones (z= 6,076; P<0,05). Porcentaje de piezas en mujeres fue significativamente mayor al de hombres (z=24,31; P<0,05). Porcentaje de piezas de las cuartas y quitas décadas de la vida (61%) superó significativamente a las demás décadas (39%) (z=9,88; P<0,05). El porcentaje de piezas con caries fue significativamente mayor al resto de las piezas con otras condiciones (41%) (z= 8,074; P<0,05). El porcentaje de piezas en pacientes sanos (77%) fue significativamente mayor al resto de las condiciones (23%) (z=24,310; P<0,05). El porcentaje de calcificaciones en cámara (78%) fue significativamente mayor a las del conducto (22%) (z=25,21; P<0,05). En conclusión, la presencia de este tipo de calcificaciones es frecuente en molares de pacientes femeninos y edad adulta. Es importante detectarlos radiográficamente porque complican la realización del tratamiento endodóntico, especialmente si están adheridos y obliteran la entrada de los conductos (AU)

Volume measurement of mandibular teeth pulp chamber as a prediction tool of gender and ethnicity in a Brazilian population / Medição do volume da câmara pulpar de dentes inferiores como ferramenta de predição de gênero e etnia em uma população brasileira

Objective: Forensic dentistry has used some methods for the human identification process. However, there is a need to study characteristics that are able to perform identification more specifically, increasing accuracy. Considering the role of dental arch assessment in prediction of gender and ethnicity, the purpose of this study was to assess the volume of pulp chamber as a mean to obtain new forensic evidence. Material and methods: For this task, 1.190 cone beam computed tomography (CBCT) images were retrospectively selected and subdivided according to the population number, gender, age and ethnicity. All DICOM files were imported to the open-source software ITK-SNAP®(http://www.itksnap.org/pmwiki/pmwiki.php). The segmentation process was performed in all pulp chamber aiming to obtain pulp tissue ́s volume. Results: As a result, the pulp chamber volume of mandibular canine teeth showed to be larger in white population than in non-white (P-value = 0.003) and in male individuals in comparison with female (P-value = 0.038). Conclusion: These results, however, must be confirmed by future studies with a larger sample size and by the assessment of other variables, including texture analysis and density of dental tissues. (AU)

Objetivo: A odontologia forense tem usado alguns métodos para o processo de identificação humana. Porém, há a necessidade de estudar características que consigam de forma mais específica realizar a identificação aumentando a precisão. Considerando o papel da avaliação da arcada dentária na predição de gênero e etnia, o objetivo deste estudo foi avaliar o volume da câmara pulpar mandibular como meio de obtenção de novas evidências periciais. Material e métodos: Foram selecionadas 1.190 imagens de tomografia computadorizada de feixe cônico (TCFC) e subdivididas de acordo com o número da população, sexo, idade e etnia. Todos os arquivos em formato DICOM foram importados para o software de código aberto ITK-SNAP® (http://www.itksnap.org/pmwiki/pmwiki.php) onde o processo de segmentação foi realizado em todas as câmaras pulpares visando a obtenção da volumetria. Resultados: Como resultado, o volume da câmara pulpar dos caninos inferiores mostrou-se maior na população branca do que na não branca (P-valor = 0,003), no sexo masculino em comparação ao feminino (P-valor = 0,038). Conclusão: Esses resultados, entretanto, devem ser confirmados por estudos futuros com maior tamanho amostral e pela avaliação de outras variáveis, incluindo análise de textura e densidade dos tecidos dentários. (AU)

Estudo in vitro da morfologia dos canais radiculares do primeiro pré-molar inferior, utilizando tomografia computadorizada de feixe cônico / In vitro study of mandibular first premolar root canals morphology using cone-beam computed tomography

Introdução: o tratamento endodôntico objetiva limpar e modelar o sistema de canais radiculares. O preparo químico-mecânico e a obturação tridimensional (3D) do sistema de canais radiculares são baseados no conhecimento da anatomia dentária interna. As radiografias convencionais e periapicais digitais apresentam limitações na definição da imagem, devido à anatomia 3D do elemento a ser tratado, que é compactada em uma imagem bidimensional. A tomografia computadorizada de feixe cônico (TCFC) é, atualmente, um interessante instrumento para análises anatômicas, devido à precisão volumétrica e ausência de sobreposição de estruturas. Métodos: foram analisados, in vitro, sessenta e quatro (n = 64) primeiros pré-molares inferiores humanos extraídos por indicação terapêutica. Em seguida, foram feitos protótipos com gengiva artificial de silicone, posicionando-se os elementos de forma semelhante a arcadas, para serem geradas as imagens de TCFC e analisadas por um endodontista experiente. O número de canais por raiz foi quantificado em cada elemento dentário e suas configurações anatômicas foram descritas seguindo a classificação de Vertucci. Resultados: foram encontrados 59% de canais Tipo I (n = 38); 0% do Tipo II (n = 0); 9% do Tipo III (n = 6); 6% do Tipo IV (n = 4); 16% do Tipo V (n = 10); 3% do Tipo VI (n = 2); 5% do Tipo VII (n = 3); 0% do Tipo VIII (n = 0) e 2% do Tipo C-shaped. Conclusão: as imagens de TCFC revelam em 3D a anatomia dentária interna, permitindo o planejamento da terapia endodôntica e um mapeamento detalhado da morfologia interna. O conhecimento dessa microanatomia viabiliza uma maior previsibilidade na realização do tratamento, assim como no seu prognóstico, e possibilita melhorar a descontaminação de áreas anatômicas complexas (AU).

Introduction: Endodontic treatment aims to clean and shape the root canal system. Chemomechanical preparation and tridimensional (3D) filling of the root canal system are based on knowledge of internal dental anatomy. Conventional and periapical digital radiographs present limitations in image definition due to the tridimensional anatomy of the tooth to be treated. The 3D anatomy is compressed in a two-dimensional image. Cone-beam computed tomography (CBCT) is currently an interesting tool for anatomical analysis because of volumetric precision and absence of overlapping structures. Methods: A total of 64 (sixty-four) human mandibular first premolars were extracted for therapeutic recommendation. Then prototypes were manufactured with artificial gingiva made of silicone, positioning the teeth in a format similar to the arches. They were subjected to CBCT examination and analyzed by an experienced endodontist. The number of canals per root was quantified for each tooth, and their anatomical configurations were described following Vertucci's classification. Results: The following were found: Type I (n = 38) 59%; Type II (n = 0); Type III (n = 6) 9%; Type IV (n = 4) 6%; Type V (n = 10) 16%; Type VI (n = 2) 3%; Type VII (n = 3) 5%; Type VIII (n = 0) and C-shaped 2%. Conclusion: CBCT image reveals tridimensional anatomy on the basis of which endodontic therapy is planned. It maps internal morphology in detail. Knowledge of micro-endodontics allows for greater predictability in treatment as well as prognosis, in addition to improving decontamination of complex anatomical areas.

Bilateral taurodontism in permanent maxillary first molar

Taurodontism is a dental anomaly caused due to the failure of Hertwig's epithelial sheath to invaginate at the proper horizontal level. A huge pulp chamber, displacement of the pulpal floor apically, and no constriction at the level of the cementoenamel junction are the key features representing a taurodontic tooth. This condition is most commonly associated with permanent molars. This clinical entity occurs in the form of an isolated, singular trait in majority of the cases. However, seldom, it may be associated with syndromes or ectodermal anomalies. The large and deep pulp chamber makes instrumentation of canals difficult, thereby challenging an endodontist. This case report describes the endodontic challenge faced in cases of taurodontism as well as the clinical steps involved in its successful endodontic management. Furthermore, it shows the typical presence of bilateral hypertaurodontism with respect to the maxillary first molar.

Nd:YAG Laser therapy device for caries control and prevention and its influence on temperature of isolated tooth pulp chamber / 国际生物医学工程杂志

Objective To analyze the influence of a dental caries phototherapy device using neodymium-yttrium-aluminum-garnet (Nd:YAG) laser on the temperature of tooth pulp chamber of different sites and morphologies under different irradiation duration and power. Methods Fifty intact isolated teeth were collected and randomly divided into middle incisor group, upper right first premolar group, upper right second molar group, upper left first premolar group, and upper left second molar group. Each experimental group was irradiated according to the laser power 1.5, 1.6, 1.7, 1.8, 1.9 and 2.0 W, and the irradiation duration 30, 60, 90 s. The temperature rise of the pulp chamber was recorded with a thermocouple thermometer. Results After the laser irradiation, the temperature of the tooth pulp chamber increased, and the temperature rise was less than 5.5℃, i.e. the threshold leading to the dental pulp necrosis. Conclusions The use of laser to prevent dental caries will increase the temperature of the tooth pulp chamber, but the temperature rise in the range of 5.5 ° C is relatively safe and will not cause irreversible damage to the pulp tissue.

Effect of cooling water temperature on the temperature changes in pulp chamber and at handpiece head during high-speed tooth preparation

OBJECTIVES: It was the aim of this study to evaluate the effect of cooling water temperature on the temperature changes in the pulp chamber and at the handpiece head during high-speed tooth preparation using an electric handpiece. MATERIALS AND METHODS: Twenty-eight intact human molars received a standardized occlusal preparation for 60 seconds using a diamond bur in an electric handpiece, and one of four treatments were applied that varied in the temperature of cooling water applied (control, with no cooling water, 10°C, 23°C, and 35°C). The temperature changes in the pulp chamber and at the handpiece head were recorded using K-type thermocouples connected to a digital thermometer. RESULTS: The average temperature changes within the pulp chamber and at the handpiece head during preparation increased substantially when no cooling water was applied (6.8°C and 11.0°C, respectively), but decreased significantly when cooling water was added. The most substantial drop in temperature occurred with 10°C water (−16.3°C and −10.2ºC), but reductions were also seen at 23°C (−8.6°C and −4.9°C). With 35°C cooling water, temperatures increased slightly, but still remained lower than the no cooling water group (1.6°C and 6.7ºC). CONCLUSIONS: The temperature changes in the pulp chamber and at the handpiece head were above harmful thresholds when tooth preparation was performed without cooling water. However, cooling water of all temperatures prevented harmful critical temperature changes even though water at 35°C raised temperatures slightly above baseline.

Invitro Evaluation Of Laws Of Pulp Chamber Anatomy In North Kerala Population In India

Context: This study was conducted in the department of Conservative Dentistry and Endodontics , Govt Dental College Calicut to evaluate the anatomy of the pulp chamber and the pulp chamber oor in North Kerala population in India and to see if specic, consistent landmarks or congurations exist and are quantifiable. Aims: 1. To observe the anatomy of the pulp chamber and the pulp chamber oor. 2. To study the relationships of the pulp chamber to the clinical crown and relationship of the orice on the pulp chamber oor. 3. To verify the anatomic laws of pulp chamber anatomy in North Kerala population Settings and Design: Sixty extracted permanent molars were collected from the Department of Oral & Maxillofacial Surgery, Govt. Dental College Calicut The teeth were divided into three groups (i) 20 mandibular molar teeth with three root canals (ii) 20 mandibular molar teeth with four root canals (iii) 20 maxillary molar teeth Methods and Material: All teeth were sectioned at the level of cement enamel junction (CEJ )by using micromotor with straight handpiece and diamond disk so that the outline of the pulp chamber relative to the CEJ could be observed. Each cut section was irrigated with water, dried and examined. The teeth were analyzed at National Institute of Technology, Calicut under stereomicroscope and digital photographs were taken to record observed anatomical relationship. Statistical analysis used: Observations were statistically analysed using SPSS17 software Results, Conclusions : The present study shows that laws regarding the location of orices, namely law of orice location 1,2 and 3 were also found to be valid after the teeth were viewed under stereomicroscope.

Effect of laser treatment of dentin hypersensitivity on pulp chamber temperature / 国际生物医学工程杂志

Objective To compare the pulp chamber temperature changes of Nd:YAP laser, Nd:YAG laser and semiconductor laser with the same power during dentin hypersensitivity treatment, and to evaluate the safety of these three laser treatments for dentin hypersensitivity. Methods 50 intact third molars were collected to prepare the dentin hypersensitivity model. The samples were randomly divided into Nd:YAP laser group (n=15), Nd:YAG laser group (n=15), semiconductor laser group (n=15), and blank control group (n=5). Each experimental group was divided into three subgroups (n=5) of 0.9 W, 1.4 W, and 1.8 W according to the laser power. The experiments were conducted with the corresponding laser parameters and thermocouple thermometer was used to record the temperature changes in the pulp chamber. The control group does not do any processing. After laser irradiation, one sample was randomly taken from each group and the morphology of dentin tubules was observed by scanning electron microscopy. Results When different power lasers were used to irradiate the samples, the temperatures of the pulp chamber in each group were increased. Among them, the temperature rise of the pulp chamber was smallest in the Nd:YAP laser group, followed by the semiconductor laser group, and the temperature rise was highest in the Nd:YAG laser group, but it was still lower than 5.5 ° C that could cause pulp necrosis. Scanning electron microscopy results showed that after irradiation with different power lasers, the diameters of most dentinal tubules in the Nd:YAG laser group and the semiconductor laser group were narrowed or even melted, and the effect was better than that of the Nd:YAP laser group. Conclusion The treatment using Nd:YAP laser, Nd:YAG laser and semiconductor laser for dentin hypersensitivity will increase the temperature of the pulp chamber. However, the temperature rise is less than 5.5℃and that will not cause irreversible damage to the pulp tissue. Nd:YAG laser and semiconductor laser have better dentinal tubule blocking effect, which is more suitable for laser dentin desensitization treatment than Nd:YAP laser.

Correlations of pulp chamber height and dentine thickness of mandibular first molar with age in Chinese Han population based on cone beam computed tomography / 实用口腔医学杂志

Objective:To investigate the relationship between pulp chamber height and dentine thickness of mandibular first molar on long axis with age in a Chinese Han population by cone-beam computed tomography(CBCT).Methods:CBCT images of 420 Chinese Han subjects(210 males and 210 females) were divided into 6 age groups as follows:15-24,25-34,35-44,45-54,55-64 and 65-74 years(n=70,35 males and 35 females).The height of pulp chamber and dentine thickness of the chamber root and floor of mandibular first permanent molar on long axis was measured by Galileo software of CBCT in vertical direction and then statistical analysis was carried out.Results:On long axis,the height of pulp chamber was (0.85±0.54) mm in males and (0.79±0.51) mm in females(P>0.05);dentine thickness of the pulp chamber roof was (3.60±0.49) mm in males and (3.50±0.49) mm in females(P>0.05);and dentine thickness of the pulp chamber floor was (2.57±0.52) mm in males and (2.49±0.5) mm in females(P>0.05).With aging,the height of pulp chamber was decreased(P<0.05) and dentine thickness of mandibular first permanent molar on long axis was increased(P<0.05).Conclusion:In Chinese Han population,the of pulp chamber height of mandibular first permanent molar on long axis is related to age,The dentine thickness increased with ages,the increase of dentine thickness of pulp chamber floor is more significant than that of the roof.

Long term effect of calcium carbonate bone cement combined with bFGF in repairing pulp chamber perforation / 国际生物医学工程杂志

Objective To investigate the long-term efficacy of calcium phosphate cement combined with bFGF in repairing pulp chamber perforation and to analyze the correlation between the diameter of the perforation and the curative effect.Methods 75 patients with pulp chamber perforation (82 teeth) were enrolled and divided into the observation group and the control group according to the repair material and method.A series of subgroups were also modeled according to the diameter of the perforation,which include the control group A (≤ 1.5 mm),control group B (1.6～3 mm) and control group C (＞3 mm),as well as the observation group A (≤ 1.5 mm),observation group B (1.6～3 rmm) and observation group C (＞3 mm).The observation group was treated with calcium phosphate cement combined with bFGF,and the control group was treated with calcium phosphate cement alone.Results The total effective rate of the observation group was 97.8％,which was significant higher than 80.6％ in the control group (P＜0.05).The cure rate of the observation group A was 100％,which was significant higher than 73.3％ in the observation group B and 41.7％ in the observation group C (all P＜0.05).The total effective rates of the observation group A and B were significantly higher than 91.7％ in the observation group C (all P＜0.05).The cure rate of the control group A was 92.9％,which was significant higher than 60.0％ in the control group B and 25.0％ in the control group C (all P＜0.05).The total effective rates of the control group A (100％) and B (90.0％) were significantly higher than 91.7％ in the control group C (all P＜0.05).Conclusions Calcium phosphate cement combined with bFGF in repairing the pulp chamber perforation was significantly better than calcium phosphate cement alone.The cure rate of perforation repairing is closely related to the perforation size.The perforation with small diameter may achieve a better repairing effect.

Pulp Chamber Heating: An In Vitro Study Evaluating Different Light Sources and Resin Composite Layers

Abstract The aim of the present in vitro study was to evaluate the temperature variation inside the pulp chamber during light-activation of the adhesive and resin composite layers with different light sources. Cavities measuring 8x10 mm were prepared on the buccal surface of bovine incisors, leaving a remaining dentin thickness of 1 mm. Specimens were placed in a 37±1 °C water bath to standardize the temperature. The temperature in the pulp chamber was measured every 10 s during 40 s of light activation of the adhesive system (SBMP-3M/ESPE) and in the three consecutive 1-mm-thick layers of resin composite (Z250-3M/ESPE). Three light source devices were evaluated: Elipar 2500 (QTH), LD Max (LED low irradiance) and VALO (LED high irradiance). The results were submitted to one-way ANOVA with repeated measures and Tukey's test, both with p<0.001. The exothermic reaction warming was observed in the Z250 increments, but not in the SBMP. The high irradiance LED showed a higher temperature average (42.7±1.56 °C), followed by the quartz-tungsten-halogen light (40.6±0.67 °C) and the lower irradiance LED (37.8±0.12 °C). Higher temperature increases were observed with the adhesive and the first resin composite increment light-activation, regardless of the employed light source. From the second increment of Z250, the restorative material acted as a dispersive structure of heat, reducing temperature increases. Regardless the light source and restorative step, the temperature increased with the irradiation time. It may be concluded that the light source, irradiation time and resin composite thickness interfered in the temperature variation inside the pulp chamber.

Resumo O objetivo do presente estudo in vitro foi avaliar a variação de temperatura dentro da câmara pulpar durante a fotoativação de um sistema adesivo e de camadas de resina composta com diferentes fontes de luz. Cavidades com dimensões de 8x10 mm foram preparadas na superfície vestibular de incisivos bovinos deixando uma espessura de dentina remanescente de 1 mm. Os espécimes foram inseridos em uma cuba térmica com água à temperatura de 37±1 °C. A temperatura no interior da câmara foi medida a cada 10 s durante 40 s de ativação de luz do sistema adesivo (SBMP; 3M/ESPE) e três camadas de 1 mm de espessura consecutivas de resina composta (Z250; 3M/ESPE ). Três fonte de luz foram avaliadas: Elipar 2500 (QTH), LD Max (LED de baixa densidade de potência), VALO (LED alta densidade de potência). Os resultados foram submetidos a ANOVA de medidas repetidas a um critério e teste de Tukey (ambos com p<0,01). O aquecimento da reação exotérmica foi observado nos incrementos de resina composta, mas não no sistema adesivo. O LED de alta densidade de potência mostrou uma média de temperatura mais elevada (42,7±1,56 °C) seguido pela luz halogéna (40,6±0,67 °C) e o LED de menor densidade de potência (37,8±0,12 °C). Maiores aumentos de temperatura foram observados na fotoativação do sistema adesivo e do primeiro incremento de resina composta, independente da fonte de luz utilizada. A partir do segundo incremento de resina composta, o material restaurador agiu como estrutura dispersiva de calor, reduzindo o aumento de temperatura. Independente da fonte de luz e da etapa restauradora, a temperatura aumentou com o tempo de irradiação. Pode-se concluir que a fonte de luz, o tempo de irradiação, a espessura resina composta interferiram na variação de temperatura no interior da câmara pulpar.

Effect of 532 nm picosecond Nd∶YAG laser irradiation on temperature of the pulp chamber / 国际生物医学工程杂志

Objective To preliminarily select safe parameters for different forms of teeth by irradiating 532 nm picosecond Nd∶YAG laser on human isolated teeth with different irradiation time length and power.Methods Isolated human teeth including anterior teeth,premolars,molars were irradiated with 532 nm picosecond laser.Repeated measurements were made for each tooth by thermometer to measure the temperature of pulp chamber on different time point and power,and the temperature change (△T) was calculated.Results △T of the anterior irradiation group at 0.6 W,30 s;0.8 W,20 s and 30 s;1.0 W,10 s,20s and 30s were more than 5.6 ℃,which was the same with that of premolar group at 1.0 W,30s.△T of the molar group at 1.0 W,30 s was less than 5.6 ℃.Under certain power,the temperature of pulp chamber increased with the prolonging of irradiation time (P＜0.05).At a certain time,temperature increased with the power (P＜0.05).Conclusions It is safe to carry out operation on the parameters setting of 0.8 W,10 s and 0.6 W,20 s irradiation for anteriors teeth;0.4 W,30 s,0.8W,30 s and 1.0 W,20 s for premolar teeth,and 1 W,30 s for molar teeth.In the application of 532 nm picosecond laser,attention is required to be paid on parameter setting to control input power and irradiation time.

Endodontic treatment of a mandibular first molar with 8 canals: a case report

Presented here is a case where 8 canals were located in a mandibular first molar. A patient with continuing pain in mandibular left first molar even after completion of biomechanical preparation was referred by a dentist. Following basic laws of the pulp chamber floor anatomy, 8 canals were located in three steps with 4 canals in each root. In both of the roots, 4 separate canals commenced which joined into two canals and exited as two separate foramina. At 6 mon follow-up visit, the tooth was found to be asymptomatic and revealed normal radiographic periapical area. The case stresses on the fact that understanding the laws of pulp chamber anatomy and complying with them while attempting to locate additional canals can prevent missing canals.

Age and sex-related differences of pulp chamber size in mandibular second molars.

Aim: The aim of this study was to compare the size of the pulp chamber in mandibular second molars with the gender and age by means of panoramic radiographs. Materials and Methods: In this study, 200 panoramic radiographs of patients were randomly selected from the archives of the Faculty of Dentistry of Ondokuz Mayis University. The radiographs of the patients were measured under a stereomicroscope and categorized according to the gender and age. Results: Statistically differences were found in the mean sizes of pulp chamber between the groups under and above the age of 30 years (P < 0.05). There were significant differences in terms of “the distance between the tip of the lingual cusp to the roof of the pulp chamber”, “the distance between the tip of the lingual cusp to the floor of the pulp chamber” and “the distance from the tip of the lingual cusp to the closest point of the furcation” between the male and female genders (P < 0.05). Conclusion: It is concluded that the pulp chamber can be exposed easily in female patients, because it is less shallow than males. However, the size of pulp chamber reduces after the age of 30 years in both the genders.

Association between dentin thickness and presence of accessory foramina in human permanent mandibular molars

The roots and periodontal system in human dentition are closely correlated from the early stagesof dental formation, maintaining this connection after teeth are established in the oral cavitythrough the apical foramen or other communications. Aim: Therefore, the aim of this study was toevaluate the correlation between the presence of foramina on the pulp chamber floor surface andin the furcation region and the thickness of dentin in this area. Methods: Forty sound permanentmandibular molars were submitted to scanning electron microscopy (SEM) to determine thepresence of foramina on the pulp chamber floor and in the furcation region, and to correlate thepresence of foramina with the variation in wall thickness in these regions. Results: The resultsshowed a mean thickness of 2.16 mm for the teeth analyzed and a 25% frequency of foramina onthe pulp chamber floor and 92.5% in furcation area, with only 22.5% showing foramina on bothsides. The foramina found on both surfaces showed varied diameters and shapes and locationsdispersed throughout the area. Conclusions: There was no significant difference between themean thicknesses of teeth featuring foramina and those without foramina.

Bilateral taurodontism in deciduous molars: A case report.

Taurodontism is a rare dental anomaly in which the involved tooth has an enlarged and elongated body and pulp chamber with apical displacement of the pulpal floor. It has a very low incidence and very few cases are reported in literature in deciduous dentition. Endodontic treatment of a taurodont tooth is challenging and requires special handling because of the proximity and apical displacement of the roots. In this article a case of five year child with bilateral involvement of mandibular second molars is presented.

The effect of concentration and application time of hydrogen peroxide on the microtensile bond strength of resin restorations to the dentin at different depths / 대한치과보존학회지

The purpose of this study was to examine the effect of hydrogen peroxide at different application time and concentrations on the microtensile bond strength of resin restorations to the deep and the pulp chamber dentin. A conventional endodontic access cavity was prepared in each tooth, and then the teeth were randomly divided into 1 control group and 4 experimental groups as follows: Group 1, non treated; Group 2, with 20% Hydrogen peroxide(H2O2); Group 3, with 10% H2O2; Group 4, with 5% H2O2; Group 5, with 2.5% H2O2; the teeth of all groups except group 1 were treated for 20, 10, and 5min. The treated teeth were filled using a Superbond C&B (Sun medical Co., Shiga, Japan). Thereafter, the specimens were stored in distilled water at 37degrees C for 24-hours and then sectioned into the deep and the chamber dentin. The microtensile bond strength values of each group were analyzed by 3-way ANOVA and Tukey post hoc test(p 0.05). The higher H2O2 concentration, the more opened dentinal tubules under a scanning electron microscope(SEM) examination.

Changes in micro-TBS to pulp chamber dentin after the application of NaOCl & reversal effect by using sodium ascorbate / 대한치과보존학회지

Clinical suggestion for the limitation of application time of NaOCl solution is needed to avoid large reductions in resin-dentin bond strength. The aim of this study was to measure the change of micro-tensile bond strength after the various application time of 5.25% NaOCl solution to pulp chamber dentin in endodontic access cavity, and to evaluate the effect of 10% sodium ascorbate application for 10 min on bond strength after the treatment of 5.25% NaOCl solution. In this experiment, there were no statistical differences(p>0.05) in bond strengths between upper chamber dentin and lower chamber dentin. NaOCl-treated group for 20 min did not show any significant decrease(p>0.05) in bond strength than non-treated control group. In contrast to that, bond strengths of NaOCl-treated groups for 40 & 80 min were significantly lower(p<0.05) than that of non-treated control group. 10% sodium ascorbate retreated group for 10 min after 5.25% NaOCl application for 40 min to chamber dentin showed the recovery of bond strength significantly. However, the bond strength of sodium ascorbate retreated group after 5.25% NaOCl application for 80 min was still significantly lower(p<0.05) compared to the non-treated control group, which means the reductions in resin-dentin bond strength were not fully reversed. On the contrary, sodium ascorbate retreated group after 5.25% NaOCl application for 5 min showed significantly higher(p<0.05) bond strength compared to the control group, which demonstrates its superior recovery effect. In SEM exminations of specimens retreated with 10% sodium ascorbate after NaOCl application for 40 & 80 min showed that resin tags were formed clearly and densely, but weakly in density and homogeneity of individual resin tag compared to the control specimen.

Influence of Sodium Ascorbate on Microtensile Bond Strengths to Pulp Chamber Dentin treated with NaOCl / 대한치과보존학회지

The purpose of this study was to evaluate the influence of sodium ascorbate on microtensile bond strengths of total-etching adhesive system to pulp chamber dentin treated with NaOCl. Pulp chambers of extracted human non-caries permanent molars were treated as follows: group 1, with 0.9% NaCl; group 2, with 5.25% NaOCl; group 3, with 5.25% NaOCl and 10% sodium ascorbate for 1min; group 4, with 5.25% NaOCl and 10% sodium ascorbate for 1 min and 10ml of water; group 5, with 5.25% NaOCl and 10% sodium ascorbate for 5 min; group 6, with 5.25% NaOCl and 10% sodium ascorbate for 5 min and 10ml of water; group 7, with 5.25% NaOCl and 10% sodium ascorbate for 10 min; group 8, with 5.25% NaOCl and 10% sodium ascorbate for 10 min and 10ml of water. Treated specimens were dried, bonded with a total-etching adhesive system (Single bond), restored with a composite resin(Z250) and kept for 24h at 100% humidity to measure the microtensile bond strength. NaOCl-treated group (group 2) demonstrated significantly lower strength than the other groups. No significant difference in microtensile bond strengths was found between NaCl-treated group (group 1) and sodium ascorbate-treated groups (group 3-8). The results of this study indicated that dentin treated with NaOCl reduced the microtensile bond strength of Single bond. Application of 10% sodium ascorbate restored the bond strength of Single bond on NaOCl-treated dentin. Application time of sodium ascorbate did not have a significant effect.