Coronal microleakage of enterococcus faecalis in three types of endodontic filling (warm vertical compaction, lateral compaction, and single cone) / Microfiltración coronal de enterococcus faecalis en tres tipos de obturación endodóntica (compactación vertical caliente, compactación lateral y cono único)

ABSTRACT. Introduction: the adequate sealing of endodontic fillings is critical for a successful treatment, as it prevents the entry of microorganisms and/or their growth in case they persist within the root system. The purpose of this study was to determine bacterial microleakage time in root canals filled with the lateral compaction, warm vertical compaction, and single cone techniques. Methods: 30 single-rooted teeth extracted from humans were randomly distributed into three experimental groups (n = 8); positive and negative controls were also used (n = 6). Teeth were prepared with the corono-apical ProTaper Universal technique and obturations were performed using lateral compaction, warm vertical compaction (System B - Obtura II) and single cone. Top Seal resin-based cement was used in the three groups. Enterococcus faecalis (E. faecalis) microleakage was assessed every 24 hours for 30 days using the dual chamber model, with the lower chamber containing a pH indicator in the culture medium, which showed bacterial microleakage time. The data were statistically analyzed using one-way Anova test and Bonferroni and Tukey's post-tests. Results: the single-cone technique showed the highest level of bacterial microleakage of E. faecalis as a function of time, while lateral compaction and warm vertical compaction showed better results, with no statistically significant differences between them, being the techniques with the best sealing results against E. faecalis microleakage. Conclusions: under the conditions of this study, it can be concluded that the single-cone technique is not suitable for root canal sealing, as it does not prevent bacterial microleakage of E. faecalis compared to the other two techniques.

RESUMEN. Introducción: un adecuado sellado de la obturación endodóntica es crucial para el éxito del tratamiento, ya que impide la entrada de microorganismos y/o el crecimiento de los mismos en caso de persistir en la anatomía radicular. El propósito de este estudio fue determinar el tiempo de microfiltración bacteriana en conductos obturados con condensación lateral, condensación vertical caliente y cono único. Métodos: 30 dientes unirradiculares extraídos de humanos se distribuyeron aleatoriamente en tres grupos experimentales (n = 8); adicionalmente, se usaron controles positivos y negativos (n = 6). Los dientes fueron conformados con técnica coronoapical ProTaper universal y las obturaciones se realizaron usando compactación lateral, compactación vertical caliente (System B - Obtura II) y cono único. Para los tres grupos se utilizó cemento resinoso Top Seal. La microfiltración con Enterococcus faecalis (E. faecalis) se evalúo cada 24 horas por 30 días usando el modelo de doble cámara, donde la cámara inferior presentaba un indicador de pH en el medio de cultivo, el cual indicaba el momento de microfiltración bacteriana. Los datos fueron analizados estadísticamente usando el test de Anova de una vía y los postests de Bonferroni y Tukey. Resultados: la técnica de cono único presentó la mayor microfiltración bacteriana de E. faecalis en función del tiempo, mientras que las técnicas de compactación lateral y compactación vertical caliente presentaron mejores resultados, aunque entre ellas no presentaron diferencias estadísticamente significativas, siendo estas dos últimas técnicas las que mejores resultados presentaron a nivel de sellado contra la microfiltración de E. faecalis. Conclusiones: bajo las condiciones de este estudio, se puede concluir que la técnica de cono único no es adecuada para el sellado de conductos radiculares, ya que no impide la microfiltración bacteriana de E. faecalis en comparación con las otras técnicas.

Theoretical distribution of gutta-percha within root canals filled using cold lateral compaction based on numeric calculus / 华中科技大学学报（医学）（英德文版）

This study aimed to present a new method based on numeric calculus to provide data on the theoretical volume ratio of voids when using the cold lateral compaction technique in canals with various diameters and tapers. Twenty-one simulated mathematical root canal models were created with different tapers and sizes of apical diameter, and were filled with defined sizes of standardized accessory gutta-percha cones. The areas of each master and accessory gutta-percha cone as well as the depth of their insertion into the canals were determined mathematically in Microsoft Excel. When the first accessory gutta-percha cone had been positioned, the residual area of void was measured. The areas of the residual voids were then measured repeatedly upon insertion of additional accessary cones until no more could be inserted in the canal. The volume ratio of voids was calculated through measurement of the volume of the root canal and mass of gutta-percha cones. The theoretical volume ratio of voids was influenced by the taper of canal, the size of apical preparation and the size of accessory gutta-percha cones. Greater apical preparation size and larger taper together with the use of smaller accessory cones reduced the volume ratio of voids in the apical third. The mathematical model provided a precise method to determine the theoretical volume ratio of voids in root-filled canals when using cold lateral compaction.

Sealing ability of two commonly used root canal sealers with and without smear layer

AIM: The aim of current research was to find out the sealing ability of two commonly used sealers in the presence and absence of smear layer at different time interval. MATERIAL AND METHODS: Total of 180 single rooted vital teeth were used. Transversal section was made with the help of digital slow speed cutting saw to divide the root and crown part. After removal of crown roots part was instrumented and prepared. The 180 teeth were randomly divided into two equal groups (n=90) 1 and 2. In group 1 the smear layer was kept intact but it was removed from group 2 with EDTA (17%). Group 1 was then divided into two sub-groups, A1, A2. Group 2 was again separated into two sub-groups, B1 and B2. Each sub-group contained of 45 samples. In sub-groups A1 and B1, AH Plus sealer, in sub-groups A2 and B2, Ketac-endo sealer and cold lateral condensation technique was used for obturation with gutta percha. All samples were kept in an incubator at 37°C for 24 hours, with help of nail polish/varnish all samples root surfaces was painted only excluding apical area after words each sub group were further divided in to three groups of 15 to represent immersion periods of 7,15 and 30 days. All samples were then kept in 5 % methylene blue dye solution at 37o c for their respective time periods. After specific time period, the roots of every group were cut longitudinally and evaluate under a stereomicroscopes to evaluate apical micro leakage in millimeter. Data was subjected to Repeated measure ANOVA with post-hoc analysis using Tukey and bonferroni tests. RESULTS: Overall analysis indicated significant reduction in sealing ability canals in with and without smear layer over different time periods (p <0.0001). CONCLUSION: Current study has concluded that AH plus sealer provides significantly better seal in the absence of smear layer than in the presence of smear layer in addition it gave better seal than Ketac-Endo sealer in the absence and presence of smear layer.

Evaluation of single root canals filled using the lateral compaction, tagger's hybrid, microseal and guttaflow techniques

The aim of this study was to determine the percentage of voids, gutta-percha and root canal sealer using 4 different filling techniques. Fifty-two extracted maxillary lateral incisors were prepared using the crown-down pressureless technique. The teeth were randomly divided in 4 groups (n=13): Lateral compaction (LC), Tagger's hybrid (TH), MicroSeal (MS) and GuttaFlow (GF) techniques. Horizontal cross-sections were made at the 2, 10 and 15 mm levels from the apex. Digital images of the root canal areas were acquired using a stereomicroscope and examined using the Image Tool 3.0 software. Statistical analysis was performed using the Kruskal-Wallis test (α=0.05). In general, a significant decrease in the gutta-percha filled area and increase of sealer area were observed at the apical level for all the evaluated techniques (p<0.05). With regard to the presence of voids, no significant difference was found. MS and TH techniques showed a larger gutta-percha filled area than LC and GF techniques at the coronal and middle third level (p<0.05). From the results of the present study, it may be concluded that the gutta-percha filled area of fillings decrease at the apical level, regardless of the filling technique used.

O objetivo do estudo foi determinar a porcentagem de espaços vazios, guta-percha e cimento após a obturação por 4 diferentes técnicas. Cinquenta e dois incisivos laterais superiores humanos extraídos foram instrumentados pela técnica coroa-ápice sem pressão. Os dentes foram randomicamente divididos em 4 grupos (n=13): Condensação lateral (LC), Técnica híbrida de Tagger (TH), MicroSeal (MS) e GuttaFlow (GF). Foram feitas secções horizontais a 2, 10 e 15 mm do ápice. Imagens digitais foram obtidas dos canais por meio de estereomicroscópio e analisadas no programa Image Tool 3.0. A análise estatística foi feita utilizando o teste de Kruskal-Wallis (α=0,05). Em geral foi observado um significante decréscimo na área de guta-percha e um aumento na área de cimento para todas as técnicas analisadas (p<0,05). Com relação à presença de espaços vazios, não houve diferença estatística entre as técnicas (p>0,05). As técnicas MS e TH apresentaram área de guta-percha maior que as técnicas LC e GF nos terços médio e cervical (p<0,05). Após análise dos resultados foi possível concluir que a área de guta-percha nas obturações diminui em sentido apical, independente da técnica utilizada.

Obturation efficiency of non-standardized gutta-percha cone in curved root canals prepared with 0.06 taper nickel-titanium instruments / 대한치과보존학회지

The purpose of this study was to evaluate the obturation efficiency of a non-standardized gutta-percha cone in curved root canals prepared with 0.06 taper nickel-titanium instruments. Sixty simulated curved root canals in clear resin blocks were prepared with crown-down technique using 0.06 taper rotary ProTaper(TM) and ProFile (Dentsply-Maillefer) until apical canal was size 30. Root canals were randomly divided into 4 groups of 15 blocks and obturated with cold-laterally compacted gutta-percha technique by using either a non-standardized size medium gutta-percha cone or an ISO-standardized size 30 one as a master cone. Gutta-percha area ratio were calculated at apical levels of 1, 3, and 5 mm using AutoCAD 2000 after cross-sectioning, and the data were analyzed with one-way and two-way ANOVAs and Duncan's multiple range test. Non-standardized size medium cone groups showed significantly higher gutta-percha area ratio than standardized cone groups at all apical levels (p < 0.01). Non-standardized cone groups used significantly less accessory cones than standardized cone groups (p < 0.01).

Influence of plugger penetration depth on the apical extrusion of root canal sealer in continuous wave of condensation technique / 대한치과보존학회지

The purpose of this study was to evaluate the influence of plugger penetration depth on the apical extrusion of root canal sealer during root canal obturation with Continuous Wave of Condensation Technique. Root canals of forty extracted human teeth were divided into four groups and were prepared up to size 40 of 0.06 taper with ProFile. After drying, canals of three groups were filled with Continuous Wave of Condensation Technique with System B(TM) and different plugger penetration depths of 3, 5, and 7 mm from the apex. Canals of one group were filled with cold lateral compaction technique as a control. Canals were filled with non-standardized master gutta-percha cones and 0.02 mL of Sealapex. Apical extruded sealer was collected in a container and weighed. Data was analyzed with one-way ANOVA and Duncan's Multiple Range Test. 3 and 5 mm penetration depth groups in Continuous Wave of Condensation Technique showed significantly more extrusion of root canal sealer than 7 mm penetration depth group (p < 0.05). However, there was no significant difference between 7 mm depth group in Continuous Wave of Condensation Technique and cold lateral compaction group (p < 0.05). The result of this study demonstrates that deeper plugger penetration depth causes more extrusion of root canal sealer in root canal obturation by Continuous Wave of Condensation Technique. Therefore, special caution is needed when plugger penetration is deeper in the canal in Continuous Wave of Condensation Technique to minimize the amount of sealer extrusion beyond apex.