Capacidad de sellado de los conductos laterales con distintas técnicas de obturación del conducto radicular / Sealing capacity of lateral canals with different root canal obturation techniques

Objetivo: Estimar y comparar la eficacia de diferentes técnicas de obturación para impedir el flujo de colorante a través de los conductos laterales. Materiales y métodos: Se emplearon 50 premolares inferiores extraídos y conservados en formol neutro al 5% hasta el momento de su uso, a los cuales se les realizaron conductos laterales artificiales. Una vez instrumentados los conductos principales, los dientes fueron divididos al azar en 5 grupos (n=10) para ser obturados con cuatro técnicas distintas: A) System B + inyección de gutapercha termoplástica del sistema Elements, Extruder; B) obturadores de Thermafil, ProTaper Universal; C) técnica híbrida y D) obturación con inyección de gutapercha termoplástica del sistema Elements, Extruder. Inmersos en tinta china y diafanizadas las raíces, se evaluó la longitud de penetración de la tinta en los conductos laterales. Se empleó el análisis de la varianza para detectar diferencias significativas (P<0,05) entre los niveles medios de penetración del colorante según las técnicas de obturación y las zonas del diente, y se efectuaron pruebas de rango múltiple (HSD de Tukey) para realizar comparaciones dos a dos, manteniendo fija la tasa de error por familia. Resultados: A la técnica B le correspondió el valor medio más bajo (30,63%) de penetración de tinta china. Los valores medios más elevados (54,52% y 51,74%) correspondieron a las técnicas A y C, respectivamente. Conclusión: Ninguna de las técnicas de obturación del conducto radicular empleadas ha sido capaz de impedir la filtración del colorante en los conductos laterales (AU)

Aim: To estimate and compare the different obturation techniques to avoid the flow of colorant through lateral canals. Materials and methods: 50 extracted lower premolars preserved in 5% neutral formol until the moment of use, had artificial lateral canals made. Once canals were instrumented, the teeth were randomly divided into 5 groups (n=10) to be filled with four different techniques: A) System B + injection of thermoplastic gutta-percha, Elements system, Extruder; B) Thermafil, ProTaper Universal obturators; C) hybrid technique, and D) injection of thermoplastic gutta-percha, Elements system, Extruder. Having immersed the premolars in India ink and diaphanized the roots, the penetration length of the India ink inside the canals was assessed. Analysis of variance was used to detect significant differences (P<0.05) between the mean levels of dye penetration according to the filling techniques and tooth areas, and multiple range tests (Tukey's HSD) were performed for two-to-two comparisons, keeping the error rate per family fixed. Results: Technique B had the lowest mean value (30.63%) of penetration. The highest mean values (54.52% and 51.74%) corresponded to techniques A and C, respectively. Conclusion: No obturation technique of the root canal used was able to avoid filtration of colourant in the lateral canals (AU)

Alteration of BAFF and APRIL in the cerebrospinal fluid based on the therapeutic response in primary central nervous system B-cell lymphoma.

We evaluated the cerebrospinal fluid (CSF) levels of the B-cell activating factor of the tumor necrosis factor family (BAFF) and A proliferation-inducing ligand (APRIL) in two cases of primary central nervous system B-cell lymphoma (PCNSBL) before and after treatment. One patient achieved clinical remission, and demonstrated decrease in the CSF levels of both BAFF and APRIL after treatment. Meanwhile, the other patient with insufficient therapeutic response showed increase in the BAFF levels despite decrease in APRIL levels. This report suggests that the combination of BAFF and APRIL levels could be useful in estimating the therapeutic efficacy in treating PCNSBL as reliable CSF markers.

y+LAT1 and y+LAT2 contribution to arginine uptake in different human cell models: Implications in the pathophysiology of Lysinuric Protein Intolerance.

y+LAT1 (encoded by SLC7A7), together with y+LAT2 (encoded by SLC7A6), is the alternative light subunits composing the heterodimeric transport system y+L for cationic and neutral amino acids. SLC7A7 mutations cause lysinuric protein intolerance (LPI), an inherited multisystem disease characterized by low plasma levels of arginine and lysine, protein-rich food intolerance, failure to thrive, hepatosplenomegaly, osteoporosis, lung involvement, kidney failure, haematologic and immunological disorders. The reason for the heterogeneity of LPI symptoms is thus far only poorly understood. Here, we aimed to quantitatively compare the expression of SLC7A7 and SLC7A6 among different human cell types and evaluate y+LAT1 and y+LAT2 contribution to arginine transport. We demonstrate that system y+L-mediated arginine transport is mainly accounted for by y+LAT1 in monocyte-derived macrophages (MDM) and y+LAT2 in fibroblasts. The kinetic analysis of arginine transport indicates that y+LAT1 and y+LAT2 share a comparable affinity for the substrate. Differences have been highlighted in the expression of SLC7A6 and SLC7A7 mRNA among different cell models: while SLC7A6 is almost equally expressed, SLC7A7 is particularly abundant in MDM, intestinal Caco-2 cells and human renal proximal tubular epithelial cells (HRPTEpC). The characterization of arginine uptake demonstrates that system y+L is operative in renal cells and in Caco-2 where, at the basolateral side, it mediates arginine efflux in exchange with leucine plus sodium. These findings explain the defective absorption/reabsorption of arginine in LPI. Moreover, y+LAT1 is the prevailing transporter in MDM sustaining a pivotal role in the pathogenesis of immunological complications associated with the disease.

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)

Temperature Rise on the Plugger Surface of 2 Commercially Available Gutta-percha Heating Devices.

INTRODUCTION: The objective of this study was to examine the temperature rise on the plugger surface of 2 commercially available gutta-percha heating devices: the System B (Kerr Dental, Amersfoort, The Netherlands) and the System B Cordless Pack Unit (Kerr Dental). METHODS: Temperature changes were recorded by a Thermocouple Data Logger device (Pico Technology Ltd, St Neots, UK) and 2 thermocouples: the first to record the temperature on the plugger surface in an isolated polytetrafluoroethylene system and the second to record the base temperature of the environment. The gutta-percha heating devices studied were System B with F, FM, M, and ML pluggers set at the "use" position, "touch" mode, temperature of 200°C, and a power setting of 10 and the System B Cordless Pack Unit with the FM plugger set at low power. Two variables were extracted from the collected temperature data: the temperature on the plugger surface 10 seconds after activating each gutta-percha heating device (θ10) and the time required to reach 60°C (t60). The differences between the pluggers over those 2 variables were investigated using analysis of variance and the Tukey B test for post hoc comparisons (P < .05). RESULTS: The mean θ10 for all pluggers ranged between 73°C and 87°C. The mean t60 for all pluggers ranged between 1.3 and 3.3 seconds. No clinically significant differences between the pluggers were observed. CONCLUSIONS: The gutta-percha heating devices tested achieve maximum temperatures lower than 94°C and are capable of gutta-percha phase transformation within approximately 4 seconds of activation.

Microfiltración apical in vitro causada por las técnicas de obturación con cono único, System B y condensación lateral clásica / In vitro apical microleakage causade by single-cone, System B and cold lateral condensation obturation techniques

La obtención de un sellado hermético en la obturación del conducto radicular es una etapa coadyuvante del éxito endodóntico. Objetivo: Comparar la microfi ltración apical in vitro, calidad de relleno y presencia de espacios vacíos en conductos radiculares obturados con los métodos de obturación cono único, condensación lateral clásica y System B. Material y métodos: Noventa raíces mesiales de molares inferiores fueron instrumentados con ProTaper a un calibre F3 y asignados aleatoriamente para su obturación a tres grupos (n = 30 raíces), grupo 1: condensación lateral clásica con gutapercha #30.02, grupo 2: cono único con gutapercha F3 y grupo 3: System B con gutapercha #30.02; en todas las técnicas se usó una mezcla de óxido de zinc eugenol como sellador.Obturados los conductos las muestras se sumergieron en azul de metileno al 0.5 por ciento, se centrifugaron a 3,200 rpm durante cinco minutos, se diafanizarony se llevaron al microscopio estereoscópico a 12.5x para la mediciónde microfi ltración apical, calidad de relleno y presencia de espacios vacíospor un observador calibrado. Resultados: No se encontraron diferencias significativas en la microfi ltración apical entre el grupo de condensación lateral clásica y System B (p > 0.05) siendo el cono único la técnica que presenta mayor fi ltración. La técnica que ofrece la menor cantidad de espacios vacíos y mejor calidad de relleno es System B. Conclusiones:El método System B y condensación lateral clásica dejan una baja microfiltración apical y adecuada calidad de relleno comparada con la que sepresenta con cono único utilizando como sellador óxido de zinc eugenol...

Expression of apical Na(+)-L-glutamine co-transport activity, B(0)-system neutral amino acid co-transporter (B(0)AT1) and angiotensin-converting enzyme 2 along the jejunal crypt-villus axis in young pigs fed a liquid formula.

Gut apical amino acid (AA) transport activity is high at birth and during suckling, thus being essential to maintain luminal nutrient-dependent mucosal growth through providing AA as essential metabolic fuel, substrates and nutrient stimuli for cellular growth. Because system-B(0) Na(+)-neutral AA co-transporter (B(0)AT1, encoded by the SLC6A19 gene) plays a dominant role for apical uptake of large neutral AA including L-Gln, we hypothesized that high apical Na(+)-Gln co-transport activity, and B(0)AT1 (SLC6A19) in co-expression with angiotensin-converting enzyme 2 (ACE2) were expressed along the entire small intestinal crypt-villus axis in young animals via unique control mechanisms. Kinetics of Na(+)-Gln co-transport activity in the apical membrane vesicles, prepared from epithelial cells sequentially isolated along the jejunal crypt-villus axis from liquid formula-fed young pigs, were measured with the membrane potential being clamped to zero using thiocyanate. Apical maximal Na(+)-Gln co-transport activity was much higher (p < 0.05) in the upper villus cells than in the middle villus (by 29 %) and the crypt (by 30 %) cells, whereas Na(+)-Gln co-transport affinity was lower (p < 0.05) in the upper villus cells than in the middle villus and the crypt cells. The B(0)AT1 (SLC6A19) mRNA abundance was lower (p < 0.05) in the crypt (by 40-47 %) than in the villus cells. There were no significant differences in B(0)AT1 and ACE2 protein abundances on the apical membrane among the upper villus, the middle villus and the crypt cells. Our study suggests that piglet fast growth is associated with very high intestinal apical Na(+)-neutral AA uptake activities via abundantly co-expressing B(0)AT1 and ACE2 proteins in the apical membrane and by transcribing the B(0)AT1 (SLC6A19) gene in the epithelia along the entire crypt-villus axis.

Comparative Evaluation of the Efficiency of Manual and Rotary Gutta-percha Removal Techniques.

INTRODUCTION: This study aimed to evaluate the efficiency of 2 manual and 2 rotary gutta-percha (GP) removal techniques in terms of both the total operating time and GP remnants left in the canal. METHODS: GP was removed with manual techniques using H-files and xylene (H + X) and H-files and System B (H + SB) (SybronEndo, Orange, CA) and with rotary techniques using the ProTaper Univeral Retreatment (PTUR) (Dentsply Maillefer, Ballaigues, Switzerland) and D-RaCe Retreatment (D-RR) (FKG Dentaire, La Chaux-de-Fonds, Switzerland) systems. The total operating time was evaluated as the time taken to reach the working length and completely remove GP until no radiopaque remnants were observed in the final radiograph. Any GP remnants left in the canal were evaluated in terms of percentage in the whole canal. RESULTS: Rotary techniques were significantly faster and left lesser GP remnants than manual techniques (P < .05). In rotary techniques, the D-RR system was significantly faster than the PTUR system (P < .05), but there was no significant difference between them regarding GP remnants (P > .05). In manual techniques, H + X was significantly faster and left lesser GP remnants than H + SB (P < .05). CONCLUSIONS: Rotary techniques were more efficient than manual techniques in GP removal. Overall, the D-RaCe Retreatment system was most efficient, whereas manual use of H-files with System B was least efficient. However, because all the techniques showed GP remnants in the canal and radiographs failed to show these remnants, additional measures would be required to ensure complete GP removal and check for cleaner canals during endodontic retreatment.

Evaluation of the effect of different root canal obturation techniques using two root canal sealers on the fracture resistance of endodontically treated roots.

AIM: The aim of this study was to compare the fracture resistance of teeth filled with AH Plus and MTA Fillapex root canal sealers by using different root canal obturation techniques. MATERIALS AND METHODS: One hundred and twenty pieces of single-rooted-and-canalled mandibular premolar teeth were selected. After the crowns were removed from the cemento-enamel junction, they were divided into 10 groups (n = 12). All the root canals except for the Group 1 were shaped until F4 file with ProTaper Nickel- Titanyum (Ni-Ti) rotary system. Group 1: was not instrumented. Group 2: the root canals were shaped but not filled. Group 3: roots were filled with cold lateral condensation technique (CLC) by using AH Plus. Group 4: roots were filled with CLC by using MTA Fillapex. Group 5: roots were filled with single cone technique by using AH Plus. Group 6: roots were filled with single cone technique by using MTA Fillapex. Group 7: roots were filled with AH Plus by using vertical compaction method with continuous heat. Group 8: roots were filled with MTA Fillapex by using vertical compaction method with continuous heat. Group 9: roots were filled with AH Plus by using thermoplastic core carrier method. Group 10: roots were filled with MTA Fillapex by using thermoplastic core carrier method. Before embedding the samples in acrylic resin after standing in an oven at 37°C for 2 weeks for the hardening of the root canal sealers the 5 mm apical portion of the roots were immersed in wax in order to imitate the surrounding tissues. Polyvinyl siloxane impression material was used for the samples which were embedded in acrylic resin in a way that the coronal 8 mm remained outside in order to imitate the periodontal ligament. Lateral force was applied to the samples with 1 mm/min speed in the Universal Tester. The maximum force values (F-max) which cause fractures in the examples were determined and the results were subjected to statistical evaluation by using one-way Anova and Tukey HSD tests with the significance set at (P < 0.05). RESULTS: The control group showed the maximum fracture resistance (P < 0.05). Thermafil group showed higher fracture resistance than single cone technique, cold lateral condensation technique, and system B (P < 0.05). CONCLUSIONS: It was concluded that shaping and widening of the root canals reduced the fracture resistance of teeth while Thermafil increased the resistance of roots against fracture.

Investigation of chemical changes in sealers during application of the warm vertical compaction technique.

AIM: To assess (i) heat generated by pluggers during warm vertical compaction of gutta-percha and investigation of temperature changes on the external root surface during canal filling, and (ii) the chemical changes of root canal sealers induced by heat. METHODOLOGY: Four sealers, namely AH Plus, MTA Plus and two other experimental sealers based on tricalcium silicate, were characterised. External temperatures generated on the root surface during warm vertical compaction of gutta-percha with different sealers inside the root canal were monitored using an infrared thermography camera. Chemical changes induced by heating the sealers were assessed by Fourier transform infrared (FT-IR) spectroscopy. RESULTS: MTA Plus and the experimental sealers were composed of a cement and radiopacifier, with epoxy resin or a water-soluble polymer as dispersant, whilst AH Plus was epoxy resin-based. The heat generated at the tips of the continuous wave pluggers was found to be lower than the temperature set and indicated on the device LCD display. The sealers reduced the heat generated on the external root surfaces during the heating phase. AH Plus sustained changes to its chemical structure after exposure to heat, whilst the other sealers were unaffected. CONCLUSIONS: The temperatures recorded at the tips of continuous wave pluggers varied with their taper and were lower than the temperature set on the System B LCD display. Root canal sealers reduced the dissipation of heat generated during warm vertical compaction, with the temperature at the external root surface maintained at 37-41 °C, a temperature below that is necessary to cause irreversible damage to bone and periodontium. The use of AH Plus sealer during warm vertical compaction techniques results in chemical changes in the sealer. The effect on sealer properties needs to be further investigated.

Investigation of the effect of sealer use on the heat generated at the external root surface during root canal obturation using warm vertical compaction technique with System B heat source.

INTRODUCTION: During warm vertical compaction of gutta-percha, root canal sealers with different chemical compositions absorb the heat generated inside the root canal. The aim of this research was to assess physicochemical modifications of sealers subjected to the System B heat source (Analytic Technology, Redmond, WA) and to evaluate the effect that the use of different sealers has on the heat transfer to the external root surface. METHODS: Three proprietary brand sealers (AH Plus [Dentsply International, Addlestone, UK], Pulp Canal Sealer [Kerr Corporation, Orange, CA], MTA Fillapex [Angelus Dental Solutions, Londrina, PR, Brazil]) and a prototype sealer based on Portland cement were assessed. The heat generated on the surfaces of System pluggers and the heat dissipation at different levels (apical, midroot, and cervical) over root surface while using different sealers was assessed using thermocouples. Data were collected in 3 different environmental conditions with the tooth suspended in air, immersed in Hank's balanced salt solution, or gelatinized Hank's balanced salt solution. Chemical changes in the sealers induced by the heat were monitored by Fourier transform infrared spectroscopy. The effect of heat changes on the setting time and compressive strength of the sealers was also assessed. RESULTS: The continuous wave plugger sustained a rise in temperature at a maximum of 80°C at the instrument shank. The highest change in temperature on the external root surface was recorded after 1.5 minutes from the start of heating, and it was restored to body temperature by 6 minutes. Environmental conditions affected heat dissipation for all the sealers in the midroot and cervical regions and the highest increase in temperature (∼60°C) recorded in air. In the midroot and cervical regions, the type of sealer used did not affect the rise in temperature. In the apical region, AH Plus obturations resulted in a greater rise in temperature, and the chemical composition of this sealer was affected by high temperature; it also induced a reduction in sealer setting time and strength. CONCLUSIONS: It could be concluded that surrounding conditions, such as temperature and humidity, exerted influence on heating dissipation during the continuous wave of the condensation obturation technique and that root canal sealers presented different conductive/isolating properties. Furthermore, the physical and chemical properties of AH Plus were negatively affected by the changes in temperature.

Temperature Profiles Along the Root with Gutta-percha Warmed through Different Heat Sources.

OBJECTIVES: To evaluate temperature profiles developing in the root during warm compaction of gutta-percha with the heat sources System B and System MB Obtura (Analityc Technology, Redmond, WA, USA). Thirty extracted human incisor teeth were used. Root canals were cleaned and shaped by means of Protaper rotary files (Dentsply-Maillefer, Belgium), and imaging was performed by micro-CT (Skyscan 1072, Aartselaar, Belgium). METHODS: Teeth were instrumented with K-type thermocouples, and the roots were filled with thermoplastic gutta-percha. Vertical compaction was achieved through the heat sources System B and System MB, and temperature profiles were detect-ed by means of NI Dac Interface controlled by the LabView System. With both heat sources, higher temperature levels were recorded in the region of the root far from the apex. When the warm plugger tip was positioned at a distance of 3 mm from the root apex, temperature levels of about 180°C were used to soften gutta-percha, and no statistically significant differences were observed between peak temperatures developed by the two heating sources at the root apex. However, a temperature level higher than 40°C was maintained for a longer time with System MB. RESULTS: Statistically significant differences were observed in peak temperature levels recorded far from the root apex. Thus, with a temperature of about 180°C and the warm plugger positioned at 3 mm from the root apex, both heating sources led to a temperature slightly higher than 40°C at the apex of the root, suggesting that the gutta-percha was properly softened. SIGNIFICANCE: A temperature level higher than 40°C was maintained for a longer time with System MB, thus providing an ad-equate time for warm compaction of the gutta-percha.

Ultramicroscopic study of the interface and sealing ability of four root canal obturation methods: Resilon versus gutta-percha.

Recently, filling materials have been introduced based on the dentine adhesion technologies used in conservative dentistry in an attempt to seal the root canal more effectively. The purpose of this study was to investigate the interface between the canal and root-filling material. Sealing ability of four root canal obturation methods was analysed by means of scanning electron microscopy. Extracted single-rooted teeth were endodontically treated and filled with gutta-percha/Pulp Canal Sealer using the Thermafil (TH) technique, gutta-percha/Pulp Canal Sealer using the System B (SB) technique, Resilon points/RealSeal (RS) and RealSeal 1/RealSeal (RS1). Specimen interfaces were analysed using field-emission scanning electron microscopy. The adhesive groups RS and RS1, formed hybrid layers but showed areas of separation (gaps) similar to those in the conventional obturation groups. The RS and RS1 groups showed less separation in the coronal third, but the separation was similar to that in the TH and SB groups in the middle and apical thirds. The sealing ability of Resilon is not superior to that of existing materials.

Interfase TopSeal-dentina en relación con dos técnicas de obturación: condensación lateral y técnica termoplastificada/termorreblandecida: estudio de microscopía electrónica de barrido / TopSeal-dentine interface after two obturation techniques: lateral condensation and thermoplastified/thermosoftened technique: a SEM study

Antecedentes: los sistemas de obturación endodóntica con condensación vertical (CV) han mejorado la calidad de los tratamientos al ser comparados con la condensación lateral (CL). Ellos permiten mejorar la difusión y la adaptabilidad del cemento sellador (CS) y la gutapercha (GP) para obtener un sellado hermético y garantizar la ausencia de brechas en la interfase del material obturador-dentina. Sin embargo, no se ha determinado si la aplicación de calor puede o no alterar la interfase de los cementos selladores a la dentina (ICS-D). Objetivo: comparar la ICS-D (TopSeal®)-dentina a diferentes distancias del ápice radicular, al utilizar dos técnicas de obturación, lateral y vertical. Método: se realizó un estudio experimental in vitro de microscopía electrónica de barrido MEB. Se tomaron 40 premolares unirradiculares recién extraídos, a los cuales se les realizó tratamiento endodóntico,utilizando la misma técnica de instrumentación. De éstos, 20 fueron obturados con CL y TopSeal®, y 20 fueron obturados con CV y el mismo cemento. Posteriormente, se seccionaron a 1, 4 y 8 mm del ápice radicular, y se observaron bajo MEB. Resultados: la ICS-D se ve modificada al utilizar las técnicas de CV cuando se compara con la CL, y se reportan valores estadísticamente significativos en todas las distancias medidas (p<0,05). Conclusiones: la técnica termoplastificada/termorreblandecida reduce la ICS-D con respecto a la CL. Sin embargo, en la primera técnica se observó mayor espesor de cemento a 1 mm de altura, lo que pudiese tener implicaciones clínicas de importancia.

Background: Vertical condensation (VC) endodontic systems have improved results of endodontic treatment when compared to lateral condensation (LC). They improve the diffusion and adaptability of the sealer cement (SC) and the gutta-percha (GP), in order to obtain a hermetic sealing and ensure the lack of cracks in the sealer material-dentine interface. However, it has not been established whether the application of heat may or not alter the sealer cement-dentine interface (SCDI). Objective: Compare the SCDI at different distances from the root apex, when using two obturation techniques, vertical (TopSeal®) and lateral. Methods: An in vitro experimental study with scanning electron microscopy (SEM) was carried out. Canals of 40 recently extracted single-root premolars were endodontically prepared with the same instrumentation technique. 20 of them were sealed with LC and TopSeal® and the other 20 were sealed with VC and TopSeal®. The specimens were then cut at 1 mm, 4 mm, and 8 mm from the root apex and observed under SEM. Results: Statistically significant differences were observed in the SCDI of teeth sealed with VC compared to those sealed with LC (p<0,05). Conclusions: The thermoplastified/thermosoftened technique reduces the SCDI when compared to the LC technique. However, the former showed a thicker cement layer on the 1 mm measures, which may have significant clinic implications.

The Effect of canal obturation according to the depth of the System B Plugger tip in the Type IV canal / 대한치과보존학회지

The purpose of this study was to evaluate the effect of the apical sealing according to the depth of the System B Plugger tip when root canal was filled with gutta-percha and sealer by Continuous Wave of Condensation technique in the Type IV canal. 50 simulated resin blocks with J-shaped curvature canals were instrumented by ProTaper (Dentsply Maillefer, Ballagiues, Switzerland) Ni-Ti files using the crown-down technique. Type IV canals were made using a broken ProTaper F3 Ni-Ti file for making a ledge at 3mm short from the working length. And ProTaper F1 Ni-Ti file was used for perforating resin block. The prepared Type IV canals were randomly divided into three experimental groups of 15 each according to the depth of System B Plugger tip. All of experimental groups were obturated with Continuous Wave of Condensation technique. The length of gutta-percha and sealer in lingual of the Type IV canals was measured with a measuring digital calliper under magnifying glass (x 2.3). The results are as follows : 1. In control group, there was no gutta-percha and sealer in lingual canal. 2. 3 mm group showed relatively more gutta-percha than 5mm or 7 mm group (p<0.05). 3. 7 mm group did not showed gutta-percha and relatively more void were observed than 3mm or 5 mm group. (p<0.05) In conclusion, within the limits of the results of this experiment, the 3 mm depth of System B Plugger tip was acceptable for obturating the Type IV canal.

Apical leakage of different gutta-percha techniques: thermafil, js quick-fill, soft core, microseal, system B and lateral condensation with a computerized fluid filtration meter.

OBJECTIVES: To investigate apical leakage of roots filled with 6 different gutta-percha techniques; Thermafil, JS Quick-Fill, Soft Core, Microseal, System B and lateral condensation using a new computerized filtration meter. MATERIALS AND METHODS: 60 extracted single rooted teeth were used. Coronal part of each tooth was removed and the root canals were prepared with step-back technique. The roots were randomly divided into six groups of 10 teeth, filled by one of the obturation technique and Kerr sealer. The teeth were kept in 100% humidity for 2 years. After this period, apical parts of roots (10 +/- 0.05 mm) were attached to computerized fluid filtration meter. Apical leakage quantity was determined as mul.cmH(2)O(-1).min(-1). RESULTS: Statistical analysis indicated that Thermafil, Soft Core, Quick-Fill and System B techniques showed lower leakage than Microseal and lateral condensation (P < .05). However, statistically no difference was found among the core techniques and no difference was found between microseal and lateral condensation techniques (P > .05). CONCLUSIONS: Thermafil, Soft Core, Quick-Fill and System B techniques showed lower leakage than Microseal and lateral condensation. In addition, this new computerized fluid filtration meter allowed quantitative measurement of leakage easily.

Comparison of apical sealing ability of continuous wave of obturation technique using EndoTwinn and System B / 대한치과보존학회지

The purpose of this study was to compare the apical leakage of the root canal filled with the System B and the EndoTwinn (the combined application of heat and ultrasonic vibration). Sixty extracted premolars with straight root were cleaned and shaped to size 35. Group SB was obturated using System B and Group ET was filled with EndoTwinn. A size 35 of 0.06 tapered gutta- percha and Adseal were used and the plugger which could be introduced to 4 mm short of working length was selected in the obturation procedure. As the positive control, Group PC was not filled. In Group SB, ET and PC, all external surfaces of each tooth were coated with nail varnish leaving only 1 mm area around the apical foramen. In the negative control of Group NSB and Group NET, all of external tooth surface including apical foramen was coated with the nail varnish. The specimens were immersed in methylene blue dye solution for 2 days. Then the specimens were sectioned at each 1 mm from apex to 5 mm level. The final score of one specimen was given by summing up of the points at all levels. The dye leakage of Group ET was significantly less than that observed in Group SB (p < 0.05). And the frequency of gutta-percha pulling out from root canal when the plugger was removed was more often with the System B than with EndoTwinn but there was no significant difference.

Scanning electron microscopic study on root canal cleaning effect using sodium hypochlorite at different temperatures / 吉林大学学报(医学版)

Objective To assess the efficacy of NaClO irrigation of root canal at different temperatures.(Methods Thirty) human teeth with single root-canal mandible premolar were instrumented using standard technique,then were divided into 3 groups,carrying on root-canal irrigation.group A: 5.25% NaClO+System B,group B:5.25% NaClO+15% EDTA,group C:5.25% NaClO+System B+15% EDTA.After the teeth root were split,the scanning electron microscope was used to observe the coronal third,middle third and apical third parts.(Results The) amount of remaining debris on root canal wall in group C decreased significantly,compared with group A and B.The differences of coronal third and middle third between group A and B,group B and C,group A and C were significant(P0.05),but there were significant differences between group A,B and C(P

Influence of plugger penetration depth on the area of the canal space occupied by gutta-percha / 대한치과보존학회지

To evaluate the ratio of gutta-percha area in the canal after canal obturation with Continuous Wave of Condensation Technique (CWCT) with varying depths of plugger penetration, forty root canals of extracted human teeth were prepared up to size 40 of 0.06 taper with ProFile(R). Canals of three groups were filled with CWCT with System B(TM) (Analytic Tech., USA) and different plugger penetration depths of 3, 5, or 7 mm from the apex. Canals of one group were filled with lateral condensation technique as a control. The filled teeth were cross-sectioned at 1, 2, and 3 mm levels from the apical foramen. The ratio of gutta-percha area in the canal was analyzed using Auto(R)Cad 2000. Data were analyzed with one-way ANOVA and Duncan's multiple range test. At all levels, higher gutta-percha area ratio was found with deeper plugger penetration depth in CWCT, and cold lateral condensation group showed higher ratio than group of plugger penetration to apical 7 mm in CWCT. At apical 1 mm and 2 mm levels, group of plugger penetration to apical 3 mm showed significantly higher gutta-percha area ratio than those of apical 7 mm and lateral condensation (p < 0.05). It is concluded therefore that, under the conditions of the present study, deeper plugger penetration depth results in more favorable and efficient obturation in CWCT.

Analysis of temperature rise on the surface of buchanan plugger using thermocouple / 대한치과보존학회지

This study was performed to evaluate the actual temperature rise on the surface of Buchanan plugger using thermocouple. The heat carrier system 'System B Heatsource' (Model 1005, Analytic Technologies, Redmond, WA, USA) and the Buchanan pluggers of F, FM, M and ML sizes are used for this study. The temperature was set to 200degrees C on digital display and the power level on it was set to 10. Five thermocouples were placed in direct contact with the surface of each size of Buchanan's pluggers at 1 mm increments from the tip to the 4 mm length of shank. The heat control spring was touched for 5 seconds, and the temperature rise on the surface of the pluggers were measured at 1 sec intervals for more than 5 seconds with an accuracy of 0.01 using Data Logger. The data were statistically analyzed by one-way ANOVA. The results were as follows. 1. The position at which the temperature peaked was approximately at 1~2 mm far from the tip of Buchanan plugger (p<0.01). 2. The peak temperature was 215.25+/-2.28degrees C in F plugger, 185.94+/-2.19degrees C in FM plugger, 169.51+/-9.12degrees C in M plugger, and 160.79+/-1.27degrees C in ML plugger and the peak temperature was highest in F plugger and followed by, in descending order, FM plugger, M plugger. ML plugger showed the lowest peak temperature (p<0.01). 3. The temperature on the pluggers was decreased with the increase of touching time. This results suggest that the actual temperature on the surface of the pluggers does not correlate well with the temperature set on digital display. Heat concentrates around the tip. The larger plugger reveals lower temperature rise relatively.