Influence of thermal effect on filling effect of bioceramic paste in different parts of root canal / 国际生物医学工程杂志

Objective:To study the effect of thermal effect on the filling effect of bioceramic paste combined with thermal gel gutta-percha vertical obturation method in different parts of root canal.Methods:Forty single-root canal teeth samples were randomly and randomized divided into the control group, the iRoot SP group, the 10 s group and the 20 s group. All tooth samples were root canal prepared to 0.04 taper after crown removal. The control group received AH-plus paste combined with thermal gel gutta-percha vertical obturation. The iRoot SP group received iRoot SP single-point filling. The 10 s group and 20 s group received iRoot SP single-point filling combined with thermal gel gutta-percha vertical obturation, in which the root canal of the two groups were heated at 180 °C for 10 s and 20 s, respectively, before using the thermosetting gutta-percha. Methylene blue staining, scanning electron microscope (SEM) observation and dental microscope observation were used to analyze the occurrence of gaps in the middle and upper segment of the root canal and the apical 1/3 of the root canal after filling.Results:For the filling in the apical 1/3 of the root canal, no obvious gap appeared in the 10 s group and the 20 s group, and there was no significant difference between the dye infection depth and the control group (all P>0.05). For the filling of the middle and upper segment of the root canal, the probability of porosity is higher when using iRoot SP combined with single-point filling. Conclusions:Short-term high temperature heating will not affect the sealing effect of iRoot SP on the apical 1/3 of the root canal. For the middle and upper segment of the root canal, the filling effect of iRoot SP single-point filling combined with thermal gel gutta-percha vertical obturation method is better than that of iRoot SP single-point filling.

Obturación del sistema de conductos radiculares: revisión de la literatura / Root canal system obturation: a review of the literature

Con el paso de los años, diferentes conceptos atribuidos a temáticas del área de la endodoncia sufren modificaciones. Una de estas etapas es la obturación del sistema de conductos radiculares, este procedimiento sumamente minucioso y crítico en la obtención de un resultado exitoso ha tenido en los últimos años importantes aportaciones en términos de aparición de nuevos materiales y técnicas dentro del campo de la endodoncia. La presente revisión de literatura retoma aspectos básicos que junto al más reciente conocimiento sobre obturación endodóncica permitirán al practicante de la endodoncia enfatizar aspectos de la última etapa operatoria del tratamiento de conductos, con el objetivo de contar con diferentes alternativas de información que le permitan actualizar sus conocimientos en el área de la endodoncia (AU)

Over the years, different thematic concepts attributed to the endodontics are modified. One such step is the sealing of the root canal system, this procedure extremely thorough and critical in obtaining a successful result, it has had in recent years important contributions in terms of new materials and techniques in the field of endodontic. This literature review basic aspects resumed by the latest knowledge about endodontic filling, allow the practitioner endodontics, emphasizing aspects of the last operative stage of root canal, aiming to have alternatives that allow them information update their knowledge on the area of endodontics (AU)

Evaluación de la microfiltración apical de BiodentineTM como material de obturación apical mediante el transporte de fluidos computarizado / Evaluation of the apical microleakage of BiodentineTM when used as an apical sealing material, using computerized fluid dynamics

Objetivo: evaluar la capacidad de BiodentineTM para resistir la microfiltración cuando es usado como material de retroobturación medianteun sistema de transporte de fluidos computarizado. Metodología: En este estudio se utilizaron 60 raíces de dientes unirradiculares, se instrumentaron y obturaron con el sistema de cono único estandarizadodel sistema ProTaper (Dentsply, Maillefer, Suiza) con ultrasonido,utilizando el sellador de conductos radiculares Silco (Silva-Collyan SLP,México). Se hizo la preparación de la cavidad retrógrada con ultrasonidoutilizando la punta E31D del sistema Retro Kit (NSK Company, Japón),con un diámetro de 2 mm. Se llevó a cabo la retroobturación con cada uno de los cementos a evaluar; grupo 1: bturados con Biodentine™ (Septodont, Francia), grupo 2: obturados con MTA Gris (Angelus™, Londrina PR, Brasil), grupo 3: control. Se utilizó un software creado específi camente para evaluar microfi ltración; éste, por medio de sensores infrarrojos, detecta la variación de voltaje de una burbuja de aire dentro de un capilar. El programa expresa el tiempo que tarda la burbuja en pasar por el segundo sensor (mm/min), los cuales se convierten a μL/min, para después expresarlos en unidades de fi ltración, realizándosemediciones en un solo lapso. Resultados: La evaluación en este estudio de la microfi ltración apical de Biodentine™ y MTA Gris Angelus™, arrojó resultados favorables para ambos; se comprobó que no existe diferencia signifi cativa en cuanto a la microfiltración entre ellos; sin embargo, ambos materiales mostraron diferentes características en cuanto a su manipulación, tiempo de fraguado y porosidad. No se presentódiferencia estadísticamente significativa entre los grupos (p = 0.256) U Mann-Whitney y Kruskal Wallis. Conclusión: El Biodentine™ y TA Gris AngelusTM presentan un comportamiento óptimo para la obturación retrógrada. Se requiere realizar otros estudios en cuanto a la interfase con la estructura dentinaria.

Objective: To evaluate, using computational fl uid dynamics, the ability of BiodentineTM to resist microleakage when used as a retro-sealing material. Methodology: In this study, 60 single-rooted teeth were used, which were biomechanically prepared and fi lled using the standardized ProTaper single-cone technique (Dentsply, Maillefer, Switzerland) and ultrasound, using Silco root-canal sealer (Silva-Collyan, SLP, Mexico). The retrograde cavity was prepared using ultrasound and a Retro Kit (NSK Company, Japan) E31D 2 mm-diameter tip. Retrograde fi lling was performed using each of the sealers to be evaluated, as follows: group 1: sealed with BiodentineTM (Septodont, France); group 2: sealed with Grey MTA (AngelusTM, Londrina PR, Brazil); group 3: control. A specially designed software was used, which measures microleakage by using infrared sensors to detect changes in voltage in an air bubble within a capillary tube. The software expresses the time it takes (mm/min) for the bubble to pass through the second sensor, then converts these measurements into μL/min to express the rate of leakage. All of the measurements are taken considering a single interval. Results: The results of the evaluation of the apical microleakage of BiodentineTM and MTA Grey AngelusTM obtained in this study were, in both cases, favorable, proving that there is no signifi cant difference between the two in this respect. However, the characteristics of each in terms of their handling, setting time, and porosity differed. No statistically signifi cant difference between the Mann-Whitney U group and the Kruskal-Wallis group was found (p = 0.256). Conclusion: The performance of Bio-dentineTM and Gray MTA AngelusTM is ideal for retrograde fi lling pur-poses. Further studies are needed, including SEM analysis, in order to determine the quality of the seal, with respect to the interface formed with the dentin structure.

Sealing ability of MTA and amalgam in different root-end preparations and resection bevel angles: an in vitro evaluation using marginal dye leakage

This in vitro study evaluated the effect of different apicoectomy angles, instruments used in root-end preparation, and dental materials used in retrofilling on apical sealing. Root ends were resected at 45 or 90 degrees in 80 single-rooted teeth. For each type of apicoectomy, root-end cavities were prepared with either a round carbide #2 bur or an S12/90D ultrasonic tip. The root-end cavities in each subgroup (apicoectomy + root-end preparation) were filled with silver amalgam without zinc (Am) or with gray mineral trioxide aggregate -Angelus (MTA), and the specimens were immediately immersed in 0.2 percent rhodamine B for 24 h. Sealing was evaluated based on the dyed cross-sectional dentin area. Data were analyzed statistically by the Kruskal-Wallis test at 5 percent significance level. No group showed complete sealing of root-end areas. The only significant factor affecting microleakage was dental material, with MTA exhibiting less leakage.

Este estudo in vitro avaliou o efeito de diferentes ângulos de apicectomia, instrumentos utilizados na retrocavitação e materiais odontológicos usados na retrobturação sobre selamento apical. Oitenta dentes unirradiculares, tratados endodonticamente, foram apicectomizados. Quarenta raízes tiveram seu ápice radicular seccionado com angulação de 45º e a outra metade com angulação de 90º. Para cada tipo de apicectomia realizou-se retrocavidades com broca esférica carbide nº 2 ou com retroponta ultra-sônica S12/90D. Cada subgrupo (apicectomia/retrocavidade) foi retrobturado com MTA ou amálgama, sendo os espécimes imediatamente imersos no corante Rodamina B a 0,2 por cento por 24 h. O selamento apical foi avaliado com base na área transversal de dentina corada ao redor da retrobturação. Os dados foram submetidos á análise estatística utilizando os testes de Kruskal-Wallis e Mann-Whitney. Nenhum grupo foi capaz de selar totalmente a região apical. O tipo de material utilizado na retrobturação foi o único fator que mostrou significativa diferença no selamento apical em relação à infiltração de corante.

Effect of immediate and delayed post space preparation on the apical seal of root canals obturated with different sealers and techniques

During mechanical preparation of the post space, the root canal filling may be twisted or vibrated, depending on several factors associated with the preparation technique and quality of filling. OBJECTIVE: The purpose of this study was to investigate the effect of immediate and delayed post space preparation on the integrity of the apical seal. MATERIAL AND METHODS: Sixty-four extracted human incisors were biomechanically prepared using the step-back technique. Sixty roots were randomly assigned to 6 experimental groups of 10 teeth each and the remaining 4 roots served as positive and negative controls (n=2). The root canals in the different groups were obturated with cold lateral and warm vertical condensation of gutta-percha and one of two sealers (Sealapex and Diaket). Post space was prepared either individually or simultaneously. An insulated copper wire was cut into 10-cm-long pieces. In each canal, one piece was inserted to maintain contact with gutta-percha and extended to the outside as one of two working electrodes. A stainless steel wire with the same dimensions of those of the copper wire, used as the other working electrode, was immersed into the background electrolyte from the center of the bottle. The electrical current between standard and experimental electrodes in canals was measured over a period of 10 days applying a conductivity meter. The Kruskal-Wallis test (p=0.05) determined whether there was a significant difference in microleakage among the groups and the Mann-Whitney U test (p=0.01) was used for multiple comparison grouping variables. RESULTS: The results suggest that only the differences between the root canal filling techniques were statistically significant (p<0.01). There were no statistically significant difference in the sealers and the times of filling removal for post space preparation (p>0.01). CONCLUSION: The quality of the root canal filling is important for the integrity of the apical seal.

Apical microleakage of MTA with 4-META/MMA & TBB resin as a root-end filling material / 대한치과보존학회지

We evaluated in vitro microleakage of Mineral Trioxide Aggregate (MTA) powder with 4-methacryloxyethyl trimellitate anhydride (4-META) / methyl methacrylate (MMA) & tri-n-butylborane (TBB) resin as a retrograde filling material by using methylene blue dye method. Fifty-two single rooted, extracted teeth were instrumented and obturated with gutta percha and AH plus sealer. The apical 3mm of each root was resected and 3mm deep ultrasonic root end preparation was done. External surface of roots was coated with nail varnish. Prepared teeth were randomly divided into five groups; Negative control: completely covered with nail varnish; Positive control: coated with nail varnish except for apical foramen; Group 1 (retrofilled with Portland cement); Group 2 (retrofilled with MTA); Group 3 (retrofilled with MTA powder mixed with 4-META/MMA & TBB resin). Immediately after completion of root-end filling, all specimens were submerged in methylene blue dye for 72 hours in 37degrees C incubator. The roots were longitudinally sectioned and measured for extent of dye penetration by three different examiners under microscope (x10). The results were statistically analyzed using one way ANOVA and Turkey's HSD test. No leakage was evident in negative control and complete leakage in positive control group. Group 3 showed significantly less leakage than group 1 and 2 (p 0.01). It was concluded that MTA powder with 4-META/MMA & TBB resin was excellent in reducing initial apical microleakage.

Microleakage of resilon: Effects of several self-etching primer / 대한치과보존학회지

The purpose of this study was to compare the apical microleakage in root canal filled with Resilon by several self-etching primers and methacrylate-based root canal sealer. Seventy single-rooted human teeth were used in this study. The canals were instrumented by a crown-down manner with Gate-Glidden drills and .04 Taper Profile to ISO #40. The teeth were randomly divided into four experimental groups of 15 teeth each according to root canal filling material and self-etching primers and two control groups (positive and negative) of 5 teeth each as follows: group 1 - gutta percha and AH26(R) sealer; group 2 - Resilon, RealSeal(TM) primer and RealSeal(TM) sealer; group 3 - Resilon, Clearfil SE Bond(R) primer and RealSeal(TM) sealer group 4 - Resilon, AdheSe(R) primer and RealSeal(TM) sealer. Apical leakage was measured by a maximum length of linear dye penetration of roots sectioned longitudinally by diamond disk. Statistical analysis was performed using the One-way ANOVA followed by Scheffe's test. There were no statistical differences in the mean apical dye penetration among the groups 2, 3 and 4 of self-etching primers. And group 1, 2 and 3 had also no statistical difference in apical dye penetration. But, there was statistical difference between group 1 and 4 (p < 0.05). The group 1 showed the least dye penetration. According to the results of this study, Resilon with self-etching primer was not sealed root canal better than gutta precha with AH26(R) at sealing root canals. And there was no significant difference in apical leakage among the three self-etching primers.

Comparison of apical seal with or without the use of dentin adhesive system / 대한치과보존학회지

The purpose of this study was to compare the sealing ability of root canal obturation with or without the use of dentin adhesive system. Forty extracted human teeth with one canal were selected and decoronated. The teeth were divided into two Groups. The obturation procedure of Group 1 was the same as that of Group 2 with the exception of dentin adhesive system. Group 2 were obturated with dentin adhesive system, AH-26, and gutta-percha. After obturation, the teeth were immersed in methylene blue solution for 84 hours. The teeth were sectioned horizontally at 1.5 mm (Level 1), 2.0 mm (Level 2), 2.5 mm (Level 3) from the root apex using a low speed microtome. Distance of dye-penetrated surface and total dentinal surface were measured using SigmaScan Pro 5.0, and the ratio of dye-penetrated distance to the total dentinal distance was analyzed statistically by Mann-Whitney U-test. 1. In both groups, the mean leakage ratio was decreased cervically. 2. At level 1, there was no significant difference between group 1 and grpup 2 (p > 0.05). 3. At level 2 and 3, group 1 showed significantly higher mean leakage ratio than group 2 (p < 0.05). The results suggest that using dentin adhesive system in root canal obturation procedure reduces the apical microleakage.