In Vitro Cone Beam CT Analysis of the Efficacy of Three Supplementary Steps In the Removal of Obturation Material in Endodontic Retreatment.

OBJECTIVES: To evaluate and compare the efficacy of XP-endo Finisher R (FKG Dentaire, Le Locle, Neuchatel, Switzerland), EDDY (VDW Dental, Munich, Germany), and passive ultrasonic irrigation (PUI) as supplementary steps following the D-RaCe retreatment file system (FKG Dentaire) in the removal of root canal obturation material using cone beam CT. MATERIALS AND METHODS: A total of 45 two-rooted permanent maxillary first premolars were selected. Following access preparation, cleaning, and shaping with Hero Shaper (Micro Mega, Besançon, BFC, France) rotary file up to 25/04%, thermoplasticized obturation was performed with TotalFill BC sealer (FKG Dentaire) and gutta-percha. The specimens were subjected to routine retreatment using the D-RaCe retreatment file system. Cone beam computed tomography (CBCT) and volumetric analysis were performed before and after this procedure. The samples were divided into group A (XP-endo Finisher R: n=15), group B (EDDY: n=15), and group C (PUI: n=15). Finally, a third CBCT was taken and a volumetric analysis was done. Statistical analysis was done using SPSS Statistics version 26.0 (IBM Corp., Armonk, NY, USA). RESULTS: The lowest mean residual volume of obturation material was seen with XP-endo Finisher R (1.6 mm3), followed by PUI (1.7 mm3). The EDDY showed the least efficiency in complete debridement of the root canals (3.6 mm3). This difference in values was statistically significant. CONCLUSION: The XP-endo Finisher R and PUI showed superior performance than EDDY in the removal of remaining obturation material from the root canal system after retreatment with the D-RaCe retreatment file system. However, none of the systems were able to completely remove the root canal obturation materials.

Effectiveness of Two Endodontic Instruments in Calcium Silicate-Based Sealer Retreatment.

The objective of the present in vitro work was to investigate the effectiveness and time required for the removal of calcium silicate-based sealer using two rotary retreatment systems. Sixty extracted, single-canal, lower premolars were used. After obturation using the single-cone technique with calcium silicate-based sealer, samples were divided into four groups according to the technique of desobturation: Group 1 (G1): D-Race; Group 2 (G2): D-Race followed by the use of XP-Endo Finisher R; Group 3 (G3): Protaper Universal Retreatment; and Group 4 (G4): Protaper Universal Retreatment followed by the use of XP-Endo Finisher R. Cone beam computed tomography (CBCT) images were used to calculate the remaining filling materials at the middle and apical thirds. Times required to perform each method were recorded. Scanning electron microscopy (SEM) and digital microscopy were used to evaluate the remaining filling materials. Data were statistically analyzed using the t-test and one way ANOVA on ranks tests. No statistically significant difference was found between G1 and G3 after CBCT observations (p > 0.05). Xp-Endo Finisher R significantly increased the ability to remove materials regardless of the initially used retreatment system (p < 0.05). Statistically significant longer time was found in G3 and G4 compared to G1 and G2, respectively (p < 0.05), to reach the full working length. No retreatment system was able to totally remove the calcium silicate-based sealer from the root canal at the middle and apical thirds (p > 0.05). Digital microscopy demonstrated that the residual materials were the remaining sealers on the canal walls. SEM showed the mineral depositions of calcium silicate materials onto the canal walls and into the dentinal tubules. However, that calcium silicate materials provide mineral deposition into the dentinal tubules might indicate that the traditional irrigants could not be sufficient to remove calcium silicate-based materials from the root canal, and other agents should be used to make retreatment considerably easier.

Efficacy of reciprocating and rotary retreatment nickel-titanium file systems for removing filling materials with a complementary cleaning method in oval canals.

OBJECTIVES: This study aimed to evaluate and compare the efficacy of the S1 reciprocating system and the D-Race retreatment rotary system for filling material removal and the apical extrusion of debris. MATERIALS AND METHODS: Sixty-four freshly extracted maxillary canines were shaped with size 10 and size 15 K-files, instrumented using ProTaper Gold under irrigation with 2.5% sodium hypochlorite (NaOCl), obturated according to the principle of thermo-mechanical condensation with gutta-percha and zinc oxide eugenol sealer, and allowed to set for 3 weeks at 37°C. Subsequently, the teeth were divided into a control group (n = 4), the D-Race rotary instrument group (n = 30), and the S1 reciprocating instrument group (n = 30). After classical retreatment, the canals were subjected to a complementary approach with the XP-Endo Shaper. Desocclusol was used as a solvent, and irrigation with 2.5% NaOCl was performed. Each group was divided into subgroups according to the timing of radiographic readings. The images were imported into a software program to measure the remaining filling material, the apical extrusion, and the root canal space. The data were statistically analyzed using the Z-test and JASP graphics software. RESULTS: No significant differences were found between the D-Race and S1 groups for primary retreatment; however, using a complementary cleaning method increased the removal of remnant filling (p < 0.05). CONCLUSIONS: Classical removal of canal filling material may not be sufficient for root canal disinfection, although a complementary finishing approach improved the results. Nevertheless, all systems left some debris and caused apical extrusion.

Comparison of the efficacy of different Ni-Ti instruments in the removal of gutta-percha and sealer in root canal retreatment.

AIMS: To evaluate and compare the efficacy of four rotary instrumentation systems in root canal retreatment and to determine retreatment time. MATERIALS AND METHODS: To achieve the purpose of this study, canals of 60 distal roots in mandibular molar teeth were selected and randomly divided into four groups A, B, C and D (n = 15). Using step-back technique, the canals were prepared and filled with gutta-percha and AH Plus employing cold lateral compaction technique. The root filling material was removed with the following retreatment systems: Group A: Mtwo R, group B: D-RaCe, group C: ProTaper R and group D: R-Endo. In order to record retreatment time, a stopwatch was used. The samples were split longitudinally, examined under a stereomicroscope, photographed and assessed with AutoCAD software. Finally, the percentages of remaining filling material were calculated and the extracted data were analyzed using one-way ANOVA and Tukey HSD test. RESULTS: All examined groups showed traces of remaining filling material within the canals. No statistically significant difference was found among the four groups in the coronal, middle, and apical thirds. The same result was obtained with regard to retreatment time (P > 0.05). However, within each one of the groups, significant difference was observed in the three regions (P < 0.05). CONCLUSIONS: Based on the findings of this study, none of the examined systems could completely remove root filling material from the root canals. However, they were all found to be effective in this regard. The most amount of remaining filling material was found in the apical third.

Evaluation of Effectiveness of Two Different Endodontic Retreatment Systems in Removal of Gutta-percha: An in vitro Study.

AIM: To determine the effectiveness of two different endodontic retreatment systems for the removal of laterally compacted gutta-percha (GP). MATERIALS AND METHODS: Sixty-three freshly extracted human maxillary central incisors were used for the study. The teeth were instrumented with K-flex files and obturated using lateral condensation technique with GP and AH Plus sealer. The teeth were divided into three retreatment groups, each group consisting of 21 teeth. Group I: D-RaCe desobturation files (D-RaCe); group II: ProTaper Universal retreatment files (PTUR); group III: Hedstrom files (H-file). After removal of GP, the teeth were split longitudinally and divided into three equal parts: Cervical, middle, and apical third. The middle and apical thirds of all root halves were examined using scanning electron microscope (SEM). The total surface area covered by the residual debris was evaluated using Motic Image plus 2.0 software. Statistical analysis was done by one-way analysis of variance (ANOVA) test with a p-value <0.05 used to determine significance and Tukey's multiple post hoc tests used for comparison between the groups, and 't' test was done for comparison between the thirds within the same group. RESULTS: The PTUR retreatment files showed overall better performance compared with D-RaCe files and H-files. The PTUR files performed better at middle third compared with others. The PTUR files and D-RaCe files performed equally at apical third better than H-files. CONCLUSION: ProTaper retreatment files are better compared with D-RaCe files and H-files for the retreatment of the previously endodontically treated teeth. CLINICAL SIGNIFICANCE: Highest efficacy for the removal of GP was shown by ProTaper Universal System followed by D-RaCe and H-file.

Efficacy of two rotary retreatment systems in removing Gutta-percha and sealer during endodontic retreatment with or without solvent: A comparative in vitro study.

OBJECTIVES: The aim of this in vitro study was to compare the efficacy of two retreatment rotary systems in the removal of Gutta-percha (GP) and sealer from the root canal walls with or without solvent. MATERIALS AND METHODS: Forty-eight extracted human mandibular first premolars were prepared and obturated with GP and AH Plus sealer. Samples were then randomly divided into four groups. Group I was retreated with MtwoR rotary system without solvent, Group II was retreated with MtwoR rotary system with Endosolv R as the solvent, Group III with D-RaCe rotary system without solvent, and Group IV with D-RaCe rotary system and Endosolv R solvent. The cleanliness of canal walls was determined by stereomicroscope (×20) and AutoCAD software. Kruskal-Wallis test and Mann-Whitney U-test were used to compare the data. RESULTS: Results showed that none of the retreatment systems used in this study was able to completely remove the root canal filling material. D-RaCe with or without solvent showed significantly (P > 0.05) less filling material at all levels compared to MtwoR with/without solvent. CONCLUSION: Within the limitation of the current study, D-RaCe rotary retreatment system is more effective in removing filling material from root canal walls when compared to MtwoR rotary retreatment system.

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.

Comparación de la capacidad de limpieza de tres sistemas rotatorios para la desobturación y retratamiento de conductos radiculares / Comparison of the cleaning ability of three rotary systems for the removal of filling materials in endodontic retreatment

El éxito de la reendodoncia está basado en gran parte en la correcta limpieza y preparación del sistema de conductos radiculares. Esto implica la eliminación de la obturación anterior y el remodelado del conducto. El material de obturación que queda en el conducto puede involucrar microorganismos y dentina infectada que comprometen el pronóstico del tratamiento. En este trabajo se comparó in vitro la eficacia de los sistemas ProTaper Universal Retratamiento (Dentsply Maillefer), D-RaCe Retratamiento (FKG) y Mtwo Retratamiento (VDW) para la remoción de conos de gutapercha y sellador. El sistema que dejó mayor residuo fue RaCe. De los otros dos sistemas, Mtwo tuvo el mejor desempeño,pero no llegó a presentar diferencias estadísticamente significativas con ProTaper. Mtwo logró una limpieza del 79,03 por ciento, seguido por el ProTaper con el 75,94 por ciento y RaCe con el 49,01 por ciento. La eliminación completa de la obturación endodóntica no se logró con ninguno de los sistemas de instrumentos investigados...

Comparación de la capacidad de limpieza en la desobturación para retratamiento con limas manuales y con los sistemas rotatorios ProTaper Universal y D-Race / Comparison of the cleaning ability of hand files and ProTaper Universal rotary systems and D-Race in the removal of filling material in retreatment

El éxito de la reendodoncia está basado en gran parte en la correcta limpieza y preparación del sistema de conductos radiculares. Esto implica la eliminación de la obturación anterior y el remodelado del conducto. El material de obturación que queda en el conducto, puede involucrar microorganismos y dentina infectada que comprometen el pronóstico del tratamiento. Por lo tanto, la eficiencia en la remoción del material de obturación es esencial para poder tener un acceso a los microorganismos remanentes y restos de tejido pulpar. El objetivo del presente trabajo fue comparar tres formas de desobturación in vitro y ver cuál eliminaba mejor el sellador y los conos de gutapercha y cuál lo lograba en menor tiempo. Se encontró que la mejor limpieza se logró con la desobturación manual. Con ProTaper se logró la limpieza en un 46 por ciento, con RaCe en un 60 por ciento y con manual en un 87,91 por ciento. Con las técnicas de desobturación mecanizada se logró el procedimiento en menor tiempo. El promedio fue de 3 min. 26 seg. con ProTaper, 2 min. 54 seg. con D-Race y de 13 min. 48 seg. con la técnica manual(AU)

Comparación de la capacidad de limpieza en la desobturación para retratamiento con limas manuales y con los sistemas rotatorios ProTaper Universal y D-Race / Comparison of the cleaning ability of hand files and ProTaper Universal rotary systems and D-Race in the removal of filling material in retreatment

El éxito de la reendodoncia está basado en gran parte en la correcta limpieza y preparación del sistema de conductos radiculares. Esto implica la eliminación de la obturación anterior y el remodelado del conducto. El material de obturación que queda en el conducto, puede involucrar microorganismos y dentina infectada que comprometen el pronóstico del tratamiento. Por lo tanto, la eficiencia en la remoción del material de obturación es esencial para poder tener un acceso a los microorganismos remanentes y restos de tejido pulpar. El objetivo del presente trabajo fue comparar tres formas de desobturación in vitro y ver cuál eliminaba mejor el sellador y los conos de gutapercha y cuál lo lograba en menor tiempo. Se encontró que la mejor limpieza se logró con la desobturación manual. Con ProTaper se logró la limpieza en un 46 por ciento, con RaCe en un 60 por ciento y con manual en un 87,91 por ciento. Con las técnicas de desobturación mecanizada se logró el procedimiento en menor tiempo. El promedio fue de 3 min. 26 seg. con ProTaper, 2 min. 54 seg. con D-Race y de 13 min. 48 seg. con la técnica manual

Comparing the Efficacy of Mtwo and D-RaCe Retreatment Systems in Removing Residual Gutta-Percha and Sealer in the Root Canal.

INTRODUCTION: Retreatment is performed in teeth with unsuccessful root canal therapy or persistent apical lesion. The most important factor for achieving successful retreatment is thorough cleaning and reshaping. NiTi files and rotary instruments are widely used for the removal of obturatants. This study compared the ability of Mtwo and D-RaCe retreatment systems to remove residual gutta-percha and sealer within the root canal after retreatment. MATERIALS AND METHODS: This in vitro experiment was performed on sixty extracted human teeth. The samples were cut at the CEJ level, manually prepared, filled with gutta-percha and AH26 and finally stored at 37ºC for two weeks. Samples were then randomly divided into two groups. Group 1 was retreated with Mtwo and Group 2 with D-RaCe. Both groups were then divided into two subgroups retreated either with or without solvent. Teeth were then vertically sectioned for evaluation of residual filling materials on the canal walls. A microscopic assessment at 16× magnification was performed. T-test statistical analysis was used to compare the data. RESULTS: Comparison between the Mtwo and D-RaCe rotary systems revealed no significant differences in residual gutta-percha or sealer on canal walls (P=0.2). The study revealed a negative effect of solvent on removal of gutta-percha and sealer in both the Mtwo and D-RaCe systems. CONCLUSION: Mtwo and D-RaCe retreatment files removed residual gutta-percha and sealer similarly; there was no significant difference between them.