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Introduction: The successful outcome of endodontic retreatment heavily relies on the thorough removal of root canal filling materials. This study aimed to quantitatively and qualitatively assess the efficacy of various retreatment file systems using nano-computed tomography (nano-CT) imaging. Materials and Methods: Thirty recently extracted human mandibular molars with mesial roots having curvatures <20° were chosen and sectioned to 16 mm in length. The root canals were prepared with the ProTaper Gold system up to size F2 and they were filled with gutta percha and AH Plus sealer. After obturation, all the samples were randomly assigned to two groups (n = 15 each) for retreatment: Group 1 utilized Solite RE Black retreatment files, while Group 2 employed Coltene HyFlex Remover files. Nano-CT imaging was employed to measure pre- and postoperative volumes of remaining filling material and remaining dentin thickness and the time taken for retreatment was measured in seconds. The obtained values were analyzed statistically (P < 0.05). Results: Nano-CT analysis showed a significant difference (P < 0.05) in the volume of remaining filling material between the Solite RE Black and Coltene HyFlex Remover groups. However, no significant difference was observed in the time required for gutta-percha removal. The Solite RE Black system showed comparatively less dentin removal than the Coltene HyFlex Remover system (P < 0.05). Conclusion: The Solite RE Black retreatment file system demonstrated promising efficacy in removing filling material while preserving dentin integrity compared to the Coltene HyFlex Remover system. These findings support its potential as an effective tool for endodontic retreatment, emphasizing the need for further clinical trials to validate its performance across various clinical scenarios. [ABSTRACT FROM AUTHOR]

Abstract Background Infected dentinal tubules are a possible source of bacteria that are responsible for the failure of root canal treatment. Therefore, disinfection of dentinal tubules by increasing the penetration of the irrigation solution is important for success in retreatment cases. This study utilized confocal laser scanning microscopy (CLSM) to assess and compare the impact of XPR, ultrasonic irrigation (UI) and sonic activation (SA) on NaOCl penetration into dentinal tubules following endodontic retreatment. Methods A total of forty mandibular premolars were enrolled in this investigation. Following root canal preparation up to ProTaper X3 file (30/0.07), root canals were obturated with gutta-percha and bioceramic root canal sealer with single cone technique. The root canal filling materials were removed using ProTaper nickel-titanium rotary retreatment files until the working length was reached. The retreatment procedure was finalized using the ProTaper Next X4 (40/0.06). The teeth were divided into four groups based on the irrigation activation technique: control (conventional needle irrigation), SA, UI and XPR. During the final irrigation procedure, Rhodamine B dye was introduced to 5% NaOCl for visualization via CLSM. Subsequent to image acquisition, the maximum penetration, penetration percentage, and penetration area were calculated. Data were statistically analyzed using the Kruskal-Wallis, Friedman, and Bonferroni Dunn multiple comparison tests through R software (p

Introduction: Endodontic retreatment differs from initial root canal treatment. Various factors govern the success of root canal treatment, and failure to achieve any of these may lead to the failure of the therapy. Retreatment decisions differ amongst general practitioners and specialists and are dependent on several factors including educational background, work experience, knowledge and economic resources. A survey was conducted to compare the practice and knowledge regarding endodontic retreatment cases amongst general practitioners and endodontists. Materials and Methods: A questionnaire was constructed with questions based on common practice and knowledge of endodontic retreatment and was distributed to general practitioners and endodontists through electronic means and personal mail. Data were analysed using the Chi-square test. P < 0.05 was considered statistically significant. Results: The results showed that there was no statistical difference in the responses by general dentists and specialists (endodontists). Conclusions: Within the limitations of this survey, it can be concluded that both the general practitioners and specialists (endodontists) have adequate knowledge and follow similar protocols when treating retreatment cases with minor differences in their approach.

Introduction: Endodontic retreatment differs from initial root canal treatment. Various factors govern the success of root canal treatment, and failure to achieve any of these may lead to the failure of the therapy. Retreatment decisions differ amongst general practitioners and specialists and are dependent on several factors including educational background, work experience, knowledge and economic resources. A survey was conducted to compare the practice and knowledge regarding endodontic retreatment cases amongst general practitioners and endodontists. Materials and Methods: A questionnaire was constructed with questions based on common practice and knowledge of endodontic retreatment and was distributed to general practitioners and endodontists through electronic means and personal mail. Data were analysed using the Chi-square test. P < 0.05 was considered statistically significant. Results: The results showed that there was no statistical difference in the responses by general dentists and specialists (endodontists). Conclusions: Within the limitations of this survey, it can be concluded that both the general practitioners and specialists (endodontists) have adequate knowledge and follow similar protocols when treating retreatment cases with minor differences in their approach. [ABSTRACT FROM AUTHOR]

Background: Infected dentinal tubules are a possible source of bacteria that are responsible for the failure of root canal treatment. Therefore, disinfection of dentinal tubules by increasing the penetration of the irrigation solution is important for success in retreatment cases. This study utilized confocal laser scanning microscopy (CLSM) to assess and compare the impact of XPR, ultrasonic irrigation (UI) and sonic activation (SA) on NaOCl penetration into dentinal tubules following endodontic retreatment. Methods: A total of forty mandibular premolars were enrolled in this investigation. Following root canal preparation up to ProTaper X3 file (30/0.07), root canals were obturated with gutta-percha and bioceramic root canal sealer with single cone technique. The root canal filling materials were removed using ProTaper nickel-titanium rotary retreatment files until the working length was reached. The retreatment procedure was finalized using the ProTaper Next X4 (40/0.06). The teeth were divided into four groups based on the irrigation activation technique: control (conventional needle irrigation), SA, UI and XPR. During the final irrigation procedure, Rhodamine B dye was introduced to 5% NaOCl for visualization via CLSM. Subsequent to image acquisition, the maximum penetration, penetration percentage, and penetration area were calculated. Data were statistically analyzed using the Kruskal-Wallis, Friedman, and Bonferroni Dunn multiple comparison tests through R software (p < 0.05). Results: In the middle third, UI yielded a significantly higher penetration percentage than the control group (p < 0.05). The UI and XPR groups showed increased penetration percentages in the coronal and middle thirds compared with the apical third (P < 0.05). Maximum penetration was notably reduced in the apical third than in comparison with the coronal and middle thirds in all groups (p < 0.05). In the control, SA and XP groups, the penetration area was ranked in descending order as coronal, middle and apical (p < 0.05). Conversely, in the ultrasonic group, the penetration area was significantly lower in the apical third than in the middle and coronal thirds (p < 0.05). Conclusions: UI enhanced the penetration percentage in the middle third of the root compared with that in the control group. XPR and SA showed no significant effect on NaOCl penetration following retreatment. [ABSTRACT FROM AUTHOR]

Dentoalveolar abscess is the term used to describe a collection of purulent secretion localized in the alveolar bone at the apex of a tooth. These abscesses can result from bacterial infections due to carious tissue, unsuccessful endodontic treatment, or pulp necrosis resulting from trauma. The symptoms involve extreme sensitivity during chewing, percussion, and palpation of the mandibular cervical lymph nodes. Treatment is performed through drainage, retreatment, or extraction, depending on the case. The aim of this study is to report the approach of an endodontic retreatment in a case of acute dentoalveolar abscess followed by prosthetic rehabilitation. [ABSTRACT FROM AUTHOR]

Background: Endodontic retreatment involves the removal of gutta-percha and sealer from root canals to address treatment failures and persistent infections. This study aimed to systematically evaluate and compare the effectiveness of different gutta-percha removal techniques. Methods: Sixty extracted human teeth with single canals were selected. The canals were initially treated, obturated with gutta-percha, and divided into six groups (n=10 each). Each group represented a distinct removal technique: rotary instrument-driven, Gates-Glidden drill-assisted, solvent-based dissolution, ultrasonic removal, heat-based softening, and a control group. Gutta-percha mass and canal wall cleanliness were assessed post-removal. Statistical analyses were performed using ANOVA and post hoc Tukey's HSD tests. Results: The solvent-based dissolution technique exhibited the most efficient removal, achieving the lowest mean remaining gutta-percha mass (0.89 ± 0.15 mg) and the highest canal wall cleanliness (95% ± 3%). The ultrasonic technique also showed effective removal capabilities with a mean remaining mass of 1.56 ± 0.22 mg and a cleanliness of 89% ± 4%. The rotary technique resulted in a mean mass of 2.47 ± 0.30 mg and cleanliness of 84% ± 5%. Gates-Glidden drill-assisted and heat-based techniques showed moderate performance with remaining masses of 3.18 ± 0.25 mg and 2.10 ± 0.20 mg, respectively, and cleanliness percentages of 78% ± 6% and 81% ± 5%. The control group had the highest remaining mass (9.88 ± 0.42 mg) and the lowest cleanliness (10% ± 2%), confirming the efficacy of the removal techniques. Conclusion: The solvent-based dissolution technique demonstrated superior efficacy in gutta-percha removal. Ultrasonic and rotary techniques were also effective choices. Clinicians should consider these findings when selecting gutta-percha removal methods for endodontic retreatment procedures. [ABSTRACT FROM AUTHOR]

The primary objective of endodontic treatments or any pulp therapy is to maintain the integrity and health of oral tissues. Endodontic treatments aim to disinfect and shape the root canal system completely and obturate it in 3D to prevent reinfection. Although initial root canal therapy has high success rates, failures can occur. The term 'retreatment' denotes a new intervention to retain the tooth in the oral cavity. Nonsurgical endodontic retreatment can preserve previously treated teeth with persistent periapical lesion(s), if the tooth is restorable and periodontally sound, and patient wants to keep it. The clinician and patient should select the treatment with the best long-term outcome. This case series describes endodontically treated teeth that required nonsurgical endodontic retreatment due to inadequate obturation, persistent periradicular lesion and loss of coronal seal. [ABSTRACT FROM AUTHOR]

ABSTRACT: Background: Bioceramic-based root canal sealers are recently utilized in endodontic treatments as materials for root canal obturation. Ensuring the complete removal of these materials during root canal retreatment is essential for proper disinfection. This investigation was carried out to evaluate the effectiveness of D-limonene, 10% formic acid, and 20% hydrochloric acid as solvents in retreating teeth previously filled with gutta-percha and AH Plus or bioceramic sealers. Materials and Methods: A total of 108 single-rooted human premolars underwent initial root canal treatment using ProTaper rotary file system. Nonsurgical retreatment was then performed using ProTaper retreatment files. The interaction between the tested sealers and solvents was examined under a stereomicroscope. ImageJ software was also used to precisely evaluate the areas covered by residual root canal obturating material. Mann–Whitney and Kruskal–Wallis tests were used to identify significant differences between the groups at a significance level of 0.05. Results: The results revealed that none of the solvents were successful in completely removing the sealers. However, greater retreatability was observed in case of AH Plus sealer characterized by the presence of less remnants as compared to bioceramic sealers. Conclusions: These findings indicate that D-limonene can effectively dissolve resin-based sealers, but not bioceramic sealers. Irrespective of the solvents used, complete elimination of BC and BCH sealers could not be accomplished. This suggests that bioceramic-based sealers significantly caused the retention of more residual material than resin-based sealer after their removal with different solvents. [ABSTRACT FROM AUTHOR]

Untreated canals are a primary cause of persistent apical periodontitis, and the inability to identify and adequately treat canals has been considered a major cause of failure of root canal therapy in maxillary molars. The purpose of this retrospective study was to use cone beam computed tomography (CBCT) to quantify the number of missed canals in maxillary first and second molars needing endodontic retreatment after treatment by general dentists. A total of 401 CBCT scans of maxillary first and second molars were examined. A total of 214 scan sets (53.37% [95% Cl, 48.48%-58.25%]) showed evidence of an untreated canal, with the highest rate (49.38%; n = 198) observed in the second mesiobuccal canal. Imaging revealed that multiple canals were missed in some patients, for a total of 225 missed canals. The examinations showed untreated first mesiobuccal canals in 2.99% of CBCT scan sets (n = 12), untreated distobuccal canals in 2.99% of CBCT scan sets (n = 12), and untreated palatal canals in 0.75% of CBCT scan sets (n = 3). Preoperative CBCT imaging should be considered prior to initial root canal treatment of maxillary molars. When the risks and limitations of CBCT are taken into consideration, the additional information it provides can improve diagnostic accuracy, increase confidence in decision-making, and positively impact treatment planning. [ABSTRACT FROM AUTHOR]

Abstract: Aim: To compare the efficiency of root canal filling removal from oval-shaped root canals with high-energy Er:YAG laser and additional instrumentation with a rotary Ni-Ti XP-Endo Finisher R system. Materials and Methods: The in vitro study was accomplished on 12 freshly extracted single-rooted mandibular incisors with one straight oval-shaped root canal, shaped with XP-Endo Shaper 30/.04 and obturated by using the warm vertical condensation technique subjected to further endodontic orthograde retreatment. Group 1: the first retreatment was carried out using a high-energy Er:YAG laser (n = 12). Group 2: the additional retreatment of the same specimens was performed with the XP-Endo Finisher-R system (n = 12). The effectiveness of the retreatment techniques was evaluated by a threefold micro-CT examination. The amount of the remaining root canal filling material was analyzed by Mann–Whitney U test and Friedman tests. Results: A significant decrease in the quantity of the root canal filling was found following the first and after the second retreatment, compared to the initial values in all examined sections (P < 0.001). Within groups, additional application of the Ni-Ti system resulted in no significant removal of the filling materials (P > 0.05). Conclusions: None of the systems resulted in complete root canal filling removal. Despite the improved results after the application of the supplementary retreatment protocol, none of the root canal walls were completely clean in the apical area. The high-energy Er:YAG laser and XP-Endo Finisher R rotary system can be successfully used in endodontic orthograde retreatment under relevant operating parameters. [ABSTRACT FROM AUTHOR]

Introduction This study aimed to compare the effectiveness of two endodontic cleaning techniques, passive ultrasonic irrigation (PUI) and the XP-endo Finisher R (XPR) system, in removing residual filling material during endodontic retreatment procedures. Materials and Methods: Forty mandibular premolars with oval canals were divided into four groups based on the sealer used (AH-Plus or Bio-C Sealer) and the cleaning technique employed (PUI or XPR). To ensure uniformity of canal volume among groups, initial micro-CT scans were conducted. The canals were instrumented, filled, and then re-instrumented before undergoing either PUI or XPR cleaning techniques. Residual filling material volumes were assessed through micro-CT scans, and statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney U tests. Results: Following instrumentation, there was no significant difference in residual filling material volumes between AH-Plus and Bio-C Sealer groups (1.35 mm³ and 1.02 mm³, respectively; P>0.05). However, after supplementary cleaning techniques, XPR-cleaned specimens exhibited significantly less residual material compared to PUI-cleaned specimens (0.01 mm³ and 0.29 mm³ for Bio-C Sealer, and 0.07 mm³ and. 0.30 mm³ for AH-Plus, P<0.05). Conclusion: The XPR system was found to be more effective than PUI in removing residual filling material from Bio-C Sealer-filled root canals. This highlights its potential as a useful supplementary cleaning technique in endodontic retreatment procedures. [ABSTRACT FROM AUTHOR]

This study analyzed the effectiveness of root canal filling removal in lower molars performed by beginner operators using optical microscopy. A total of 55 mandibular first and second molars with mesial roots exhibiting an average curvature of 10-20° were selected based on preoperative radiographs. Instrumentation was done with ProTaper Gold (Dentsply Sirona) up to F2 (25/.08), using 2ml of 2.5% NaOCl irrigation solution after each file. Root canal obturation was performed using gutta-percha points with cold lateral condensation and Sealapex (Kerr Dental). Coronal fillings were made with composite resin and stored in distilled water for two years. Removal of the root canal fillings was performed with AF Retreatment Rotary (AFRR) and AF Blue R3 (AFBR3) (Fanta Dental Materials) under reciprocating motion with 2.5% NaOCl irrigation. Cross-sections of the coronal, middle, and apical thirds were analyzed at 40x magnification using a STEINDORFF POL microscope with a digital camera. Image analysis was conducted using Image J software, version 1.54, to determine the efficiency of root canal filling removal by percentage. Statistical analysis via one-way ANOVA revealed significant differences between distal and mesial roots (P < 0.05). Specifically, for mesial roots, the removal efficiency was 70.65% in the coronal third, 54.66% in the middle third, and 21.32% in the apical third. Significant difficulties were noted due to fractured files, calcifications, and debris accumulation in the isthmuses. The study concluded that the protocol using Fanta files demonstrated significant differences in removal efficiency correlated with root curvature, compounded by the inexperience of beginner operators. The findings highlight the challenges faced by novice practitioners in achieving effective root canal filling removal. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the effectiveness of the XP-endo Finisher R (XPFR; FKG Dentaire, La Chaux-de-Fonds, Switzerland) or the Flatsonic ultrasonic tip (Helse Ultrasonic, Santa Rosa de Viterbo, SP, Brazil) in removing remaining filling material after the retreatment of flattened root canals using micro–computed tomographic imaging. Twenty-four flattened distal root canals of mandibular molars with a buccolingual diameter 4 or more times larger than the mesiodistal diameter were prepared with Reciproc Blue (RB) R40 (VDW GmbH, Munich, Germany) and filled using the Tagger hybrid technique. All canals were retreated with RB R40, and apical enlargement was performed with RB R50 (VDW GmbH). The specimens were randomly distributed into 2 groups: XPFR or Flatsonic (n = 12). The percentage of remaining filling material after retreatment and centralization ability was evaluated. Data were submitted to Mann-Whitney, Wilcoxon, and unpaired t tests (α = 5%). Greater capacity to remove remaining filling material in the entire canal and the cervical and middle thirds was observed for the Flatsonic compared with the XPFR (P <.05). However, both supplementary cleaning techniques showed a similar percentage of residual filling material in the apical third (P >.05). No difference was observed in the centralization ability between the techniques (P >.05). The Flatsonic promotes greater removal of remaining filling material than the XPFR in the retreatment of flattened root canals. However, both supplementary cleaning approaches were similar in the apical third. The XPFR and Flatsonic were able to maintain root canal centralization. [ABSTRACT FROM AUTHOR]

Objective: The purpose of this retrospective study was to assess the variables affecting endodontic retreatment technique success. Methods: A 5-year period of 500 patient records from a dental clinic were examined. Pre-operative factors, procedure specifics, post-operative results, and demographic information were all documented. The study employed statistical analysis to determine the important factors that influence retreatment success. Findings: The average age of the study group was 45.2 years, and 56% of the participants were female. Sixty-four percent of patients had multiple root canals, and the most frequent initial diagnosis (60%) was apical periodontitis. The results of the surgery varied: 50% of patients had full healing, 30% had partial healing, and 20% had no improvement at all. Significant indicators of retreatment success were found to include age, initial diagnosis, and root canal morphology (P < 0.05). Conclusion: The effectiveness of endodontic retreatment operations is mostly influenced by age, apical periodontitis, and root canal morphology. Optimizing treatment results requires individualized treatment techniques based on each patient’s unique features. Clinicians can benefit greatly from these findings in terms of increasing endodontic retreatment success rates and enhancing patient care.

Background: Endodontic retreatment is crucial for preserving dental health but is influenced by various factors. Objective: This research aimed to assess factors affecting the success of endodontic retreatment procedures. Methods: A retrospective analysis was conducted on 250 cases of endodontic retreatment. Demographic and clinical data were collected, and treatment success was defined based on predetermined criteria. Statistical analysis was performed to evaluate associations between treatment factors and retreatment outcomes. Results: The overall success rate was 75%. Rotary instrumentation, gutta-percha obturation, and use of intracanal medication were significantly associated with higher retreatment success rates (P < 0.05). Conclusion: Factors such as instrumentation type, obturation material, and intracanal medication significantly influence endodontic retreatment success. Understanding and optimizing these factors are crucial for improving treatment outcomes and patient satisfaction.

Introduction: Endodontic treatment failures often stem from the presence of microbial pathogens, particularly Enterococcus faecalis and Candida albicans. This study systematically assesses the prevalence of E. faecalis and C. albicans in endodontic retreatment cases, aiming to explore their impact on treatment outcomes. Methods: Employing a systematic sampling approach, 30 patients with a history of previous endodontic treatment were selected. Rigorous clinical and radiographic assessments were conducted, following standardized protocols for root canal sample collection. Microbiological analysis, utilizing selective culture media, was employed to identify and quantify E. faecalis and C. albicans. Statistical analyses, including chi-square and logistic regression tests, were performed. Results: The study involved 30 patients undergoing endodontic retreatment, with comprehensive clinical and radiographic evaluations for cases with and without periradicular lesions. Microbiological analysis unveiled a significant prevalence of E. faecalis and C. albicans, establishing a robust association between these pathogens and retreatment failure. These findings underscore the critical need for targeted antimicrobial interventions to enhance the overall success rates of endodontic retreatment procedures. Conclusion: This study highlights the substantial prevalence of E. faecalis and C. albicans in endodontic retreatment cases, emphasizing the importance of identifying and effectively managing these pathogens for successful treatment outcomes. The notable association between these microbial agents and retreatment failure underscores the imperative for tailored antimicrobial strategies to enhance the efficacy of endodontic retreatment procedures.

IntroductionComplex anatomy of the root canal system results in incomplete debridement with mechanical instrumentation, leaving some areas or root canal walls untouched. There comes the significance of endodontic irrigants with residual antibacterial substantivity which prolongs the post-antibiotic effect, thereby improving the success and predictability of endodontic treatment. AimTo comparatively evaluate the residual antibacterial substantivity of 2% chlorhexidine, Biopure MTAD and 2% chitosan against Enterococcus faecalis at intervals of 1, 14 and 28 days. Materials and MethodsSeventy-five therapeutically extracted permanent single rooted mandibular premolars teeth were selected. Dentin blocks of 4 mm thickness were prepared and enlarged to 1.6 mm. The autoclaved blocks were inoculated with 24-hour colonies of pure cultures of E. faecalis for 14 days. After the contamination period, canals of each dentin block were irrigated with 5 ml of sterile saline and dried with sterile paper points. A total of 75 dentin blocks were randomly divided into five groups as follows: Group A (21 specimens): 2% chlorhexidine, Group B (21 specimens): Biopure MTAD, Group C (21 specimens): 2% chitosan, Group D (6 specimens): positive control (infected dentin tubes) and Group E (six specimens): negative control (sterile dentin tubes). Then, the lumens of dentin blocks were irrigated with the respective irrigants for 10 mins and were dried using sterile paper points. The specimens were then incubated at 37°C for 28 days to maintain humidity. At experimental intervals of 1, 14 and 28 days, dentin shavings were removed from the canals of respective groups by circumferential filing with sterile no. 35 Hedstrom files. The powdered dentin samples obtained with each dentin block were observed for colony forming units (CFUs) using a Digital Colony counter and were expressed as CFUs/mL. ResultAll the irrigants in the study showed a significant decrease in CFUs from day 1 to day 28 indicating that they have residual antibacterial substantivity against E. faecalis. Group B (Biopure MTAD) showed significantly least mean CFUs compared to Group A (2% CHX) and Group C (2% chitosan) against E. faecalis at B1(day 1), B2(day 14) and B3(day 28). Group A (2% CHX) showed significantly higher mean CFUs than Group C (2% chitosan) at A1(day 1). Group C (2% chitosan) showed significantly higher mean CFUs compared to Group A (2% CHX) at C2(day 14) and C3 (day 28). ConclusionMTAD showed statistically higher residual antibacterial substantivity against E. faecalis at experimental periods of 1, 14 and 28 days. The residual antibacterial effect of 2% chitosan was better compared to 2% CHX at day 1. The residual antimicrobial substantivity of 2% CHX was higher compared to 2% chitosan at intervals of 14 and 28 days.

Introduction: Complex anatomy of the root canal system results in incomplete debridement with mechanical instrumentation, leaving some areas or root canal walls untouched. There comes the significance of endodontic irrigants with residual antibacterial substantivity which prolongs the post-antibiotic effect, thereby improving the success and predictability of endodontic treatment. Aim: To comparatively evaluate the residual antibacterial substantivity of 2% chlorhexidine, Biopure MTAD and 2% chitosan against Enterococcus faecalis at intervals of 1, 14 and 28 days. Materials and Methods: Seventy-five therapeutically extracted permanent single rooted mandibular premolars teeth were selected. Dentin blocks of 4 mm thickness were prepared and enlarged to 1.6 mm. The autoclaved blocks were inoculated with 24-hour colonies of pure cultures of E. faecalis for 14 days. After the contamination period, canals of each dentin block were irrigated with 5 ml of sterile saline and dried with sterile paper points. A total of 75 dentin blocks were randomly divided into five groups as follows: Group A (21 specimens): 2% chlorhexidine, Group B (21 specimens): Biopure MTAD, Group C (21 specimens): 2% chitosan, Group D (6 specimens): positive control (infected dentin tubes) and Group E (six specimens): negative control (sterile dentin tubes). Then, the lumens of dentin blocks were irrigated with the respective irrigants for 10 mins and were dried using sterile paper points. The specimens were then incubated at 37°C for 28 days to maintain humidity. At experimental intervals of 1, 14 and 28 days, dentin shavings were removed from the canals of respective groups by circumferential filing with sterile no. 35 Hedstrom files. The powdered dentin samples obtained with each dentin block were observed for colony forming units (CFUs) using a Digital Colony counter and were expressed as CFUs/mL. Result: All the irrigants in the study showed a significant decrease in CFUs from day 1 to day 28 indicating that they have residual antibacterial substantivity against E. faecalis. Group B (Biopure MTAD) showed significantly least mean CFUs compared to Group A (2% CHX) and Group C (2% chitosan) against E. faecalis at B1(day 1), B2(day 14) and B3(day 28). Group A (2% CHX) showed significantly higher mean CFUs than Group C (2% chitosan) at A1(day 1). Group C (2% chitosan) showed significantly higher mean CFUs compared to Group A (2% CHX) at C2(day 14) and C3 (day 28). Conclusion: MTAD showed statistically higher residual antibacterial substantivity against E. faecalis at experimental periods of 1, 14 and 28 days. The residual antibacterial effect of 2% chitosan was better compared to 2% CHX at day 1. The residual antimicrobial substantivity of 2% CHX was higher compared to 2% chitosan at intervals of 14 and 28 days. [ABSTRACT FROM AUTHOR]

Endodontic treatment failures often stem from the presence of microbial pathogens, particularly Enterococcus faecalis and Candida albicans. This study systematically assesses the prevalence of E. faecalis and C. albicans in endodontic retreatment cases, aiming to explore their impact on treatment outcomes. Employing a systematic sampling approach, 30 patients with a history of previous endodontic treatment were selected. Rigorous clinical and radiographic assessments were conducted, following standardized protocols for root canal sample collection. Microbiological analysis, utilizing selective culture media, was employed to identify and quantify E. faecalis and C. albicans. Statistical analyses, including chi-square and logistic regression tests, were performed. The study involved 30 patients undergoing endodontic retreatment, with comprehensive clinical and radiographic evaluations for cases with and without periradicular lesions. Microbiological analysis unveiled a significant prevalence of E. faecalis and C. albicans, establishing a robust association between these pathogens and retreatment failure. These findings underscore the critical need for targeted antimicrobial interventions to enhance the overall success rates of endodontic retreatment procedures. This study highlights the substantial prevalence of E. faecalis and C. albicans in endodontic retreatment cases, emphasizing the importance of identifying and effectively managing these pathogens for successful treatment outcomes. The notable association between these microbial agents and retreatment failure underscores the imperative for tailored antimicrobial strategies to enhance the efficacy of endodontic retreatment procedures. [ABSTRACT FROM AUTHOR]

This study evaluated changes in the root canal length (RCL) and the accuracy of the electronic apex locator (EAL) during the different stages of endodontic treatment and retreatment. Fifty-six mesial root canals of mandibular molars were selected. The actual root canal length (AL) of the canals was obtained by inserting a size 15 hand file up to the apical foramen, under magnification. The electronic lengths were obtained at the "APEX" mark of Root ZX II, using an alginate model. Both measurements were performed at three different stages of the initial root canal treatment—unflared, flared, and concluded—and at two stages of retreatment, after achieving patency and repreparation. Data were statistically analyzed and the significance level established was 5%. All stages produced a significant reduction in the AL (p < 0.05). The greatest variation was observed between the unflared–flared stages (0.2 mm) and between concluded–patency stages (0.09 mm), with no difference between them (p > 0.05). The accuracy of Root ZX II was negatively affected after achieving patency, presenting statistically significant difference compared to the other stages (p < 0.05). A significant reduction in the RCL was observed along the different stages of endodontic treatment and retreatment. The EAL was accurate to measure the root canals in most stages, except after achieving patency for endodontic retreatment. Determining and monitoring the RCL is an essential step towards a favorable prognosis, since it reduced along the different stages evaluated. Root ZX II was not accurate for endodontic retreatment. [ABSTRACT FROM AUTHOR]

Objectives: To compare the efficacy of fiber post removal using conventional (CONV) versus guided endodontics (GE) in terms of dentin loss, residual resin material, procedural errors, and working time in vitro. Material and methods: Ninety human central incisors were root-filled and scanned by micro-computed tomography (CT), then restored with fiber posts and composite. Twenty-four sets of teeth with up to four human maxillary central incisors were fabricated and divided into three groups: conventional post removal by a general dentist (CG) or endodontology specialist (CS) and guided endodontics (GE) by a general dentist, yielding 30 teeth per operator and group. After treatment, the prepared access cavities were volumetrically assessed by micro-CT. Statistical significance was evaluated by one-way analysis of variance followed by post hoc comparisons with Tukey's HSD test and Pearson's chi-squared test for independence. Results: Both CONV and GE resulted in dentin loss and residual resin material. CS resulted in more dentin loss and less residual resin material than CG and GE (p <.05). All groups had some deviations from the original root canal but no perforations. The shortest working time was observed in the GE group. Conclusions: Compared to the conventional freehand technique, GE resulted in significantly less radicular dentin loss, a few deviations but no perforations. Clinical relevance: Guided endodontics can improve the speed and safety of fiber post removal without root perforation. [ABSTRACT FROM AUTHOR]

Abstract Background It is currently unknown whether rotary file motion affects the best outcome of root canal retreatment. This experimental study compared the efficacy, efficiency, and complications of single-use NiTi rotary files using continuous rotation, reciprocating, and adaptive motions in root canal filling removal in curved root canals. Reciproc blue R25 was used with reciprocating motion (RB), VDW.ROTATE retreatment files with continuous rotation (VR), and ProTaper NEXT X2 with continuous rotation (PTNc) or adaptive motion (PTNa). Methods Forty mesial root canals of extracted mandibular first and second molars with an angle of curvature between 20°–40° and a radius of curvature between 5 and 10 mm were collected. The specimens were instrumented and obturated with gutta-percha and AH Plus sealer using the continuous wave of condensation technique. The specimens were randomly divided into 4 retreatment groups (n = 10), RB, VR, PTNc, and PTNa. The percentage of root canal filling removal in each group was analyzed using Micro-Computed Tomography (µCT). The motor running time, total time, root canal complication, and instrument complication were recorded and statistically analyzed (p-value

Alessio Zanza, Rodolfo Reda, Luca Testarelli Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, Rome, ItalyCorrespondence: Rodolfo Reda, Department of Oral and Maxillo-Facial Sciences, Sapienza University of Rome, Via Caserta 06, Rome, 00161, Italy, Email rodolfo.reda@uniroma1.itAbstract: Endodontic orthograde retreatments are considered one of the possible treatment options in case of post-treatment diseases considering the promising results present in the literature. Despite this, a plethora of articles have been published on this topic, and drawing conclusions could be challenging. For this reason, this review aims to summarize the crucial points on each aspect of non-surgical endodontic retreatments, discussing and comparing the current protocols, techniques, materials, and indications. Taking into consideration data from the literature, in terms of diagnosis, CBCT should be considered the first choice, since it can thoroughly affect the diagnosis and treatment plan. Regarding the procedural phases, some conclusions can be drawn: when present, coronal restoration materials such as crowns, partial prostheses, post, and core should be removed; the use of magnification devices, ultrasonic instruments, and an in-depth interpretation of radiographic images with both 2D and 3D images are strongly recommended during the orifice location; additional protocols such as irrigants activation, ultrasonic cleaning, and rotary or reciprocating instrumentation of treated canals are strongly recommended for filling materials removal and to achieve a high-quality chemo-mechanical disinfection; perforations should be treated as soon as possible, and the material of choice to treat them is the MTA or other calcium-silicate-based repair materials; the presence of ledges does not intrinsically reduce the success rate of RCRts if properly managed; in case of instrument fragments, their removal should be considered as the first treatment option, however many variables should be considered to select the proper technique or consider the option of bypassing.Keywords: endodontic retreatment, endodontic retreatment outcome, diagnosis, ledge, perforation, instrument fragment removal, missed anatomy, filling material removal

Aim: This study compared intracanal removal of filling as well as the frequency and volume of extruded material after retreatment with either HyFlex or Reciproc instruments in mandibular teeth from cadavers. Methodology: The root canals of 14 pairs of contralateral single‐rooted teeth in mandibles of cadavers were instrumented with Reciproc R40 and filled using lateral compaction. The mandibles were scanned in a micro‐computed tomographic (micro‐CT) device before and after retreatment procedures. The contralateral teeth were assigned to two groups (n = 14) according to the retreatment protocol using either HyFlex or Reciproc instrument systems. In the HyFlex group, the HyFlex Remover instrument was worked 3 mm short of the working length (WL), followed by HyFlex CM 40.04 and 50.04 at the WL. In the Reciproc group, the R50 instrument was worked up at the coronal two thirds, followed by two more cycles until the WL was reached. Pre‐ and post‐operative micro‐CT images were analysed for extrusion and intracanal removal of filling material. Results: After retreatment, extrusion of filling material occurred in 11 (78%) and 14 (100%) teeth from HyFlex and Reciproc groups respectively (p >.05). A similar volume of extruded material was observed after retreatment with both systems (p >.05). A significant decrease in the intracanal filling volume was verified after retreatment with both tested systems (p <.05). However, residual filling material was found in all root canals, regardless of the system. The amount of filling material removed (HyFlex = 80.8%; Reciproc = 65.9%) and the operation time was similar between systems (p >.05). Conclusions: A high frequency of filling material extrusion was observed after retreatment with the two systems in a cadaver model, with no significant difference between them. Both protocols obtained similar efficacy in filling material removal procedures, although none completely cleaned the canals. [ABSTRACT FROM AUTHOR]

Background: It is currently unknown whether rotary file motion affects the best outcome of root canal retreatment. This experimental study compared the efficacy, efficiency, and complications of single-use NiTi rotary files using continuous rotation, reciprocating, and adaptive motions in root canal filling removal in curved root canals. Reciproc blue R25 was used with reciprocating motion (RB), VDW.ROTATE retreatment files with continuous rotation (VR), and ProTaper NEXT X2 with continuous rotation (PTNc) or adaptive motion (PTNa). Methods: Forty mesial root canals of extracted mandibular first and second molars with an angle of curvature between 20°–40° and a radius of curvature between 5 and 10 mm were collected. The specimens were instrumented and obturated with gutta-percha and AH Plus sealer using the continuous wave of condensation technique. The specimens were randomly divided into 4 retreatment groups (n = 10), RB, VR, PTNc, and PTNa. The percentage of root canal filling removal in each group was analyzed using Micro-Computed Tomography (µCT). The motor running time, total time, root canal complication, and instrument complication were recorded and statistically analyzed (p-value < 0.05). Results: The pre-operative root canal curvature and root canal filling volume were comparable among groups. The percentage of root canal filling removal from the whole canal in the PTNc, RB, PTNa, and VR group was 98%, 96%, 95%, and 93%, respectively. A significant difference was observed between the PTNc and VR groups for the whole canal and the apical-third part. The motor running time and total time were significantly different between the groups. Instrument fracture was observed at 40% in the VR and 20% in the PTNa group, but none in the RB and PTNc groups. Conclusions: The ProTaper NEXT X2 with continuous rotation and RB files can be used with high efficacy and efficiency in curved root canal retreatment. Continuous rotation is more efficacious and efficient than adaptive motion when using the NiTi rotary file. Single file retreatment can be used in small canals with high efficacy, cost-effectiveness, and less time consumption. [ABSTRACT FROM AUTHOR]

Aim: Root canal treatment procedures are considered "the bread and butter" for routine clinical practice. Although retreatments have been primarily performed by endodontists (ENs), many senior practitioners and dentists who are root canal enthusiasts do opt for undertaking endodontic retreatment procedures. This survey helps us understand the practice trends and attitude of dentists undertaking endodontic retreatment procedures in and around Mumbai city. Materials and Methods: Questionnaires pertaining to endodontic retreatment were randomly distributed (hard copy/soft copy) to 1000 practicing dentists in and around Mumbai city. The questionnaire survey was divided into Part A: involving basic details such as name, demographic information, and clinical experience of the dentist and Part B: a set of questions based on assessing the trends, techniques, materials, and opinions of dentists regarding endodontic retreatment. Only those dentists who treated endodontic retreatment patients were asked to fill the Part B form. A response rate of 60.2% was achieved. Results: Out of total 602 participants, 49% of dentists (295) reported to undertake endodontic retreatment cases. Among the 295 respondents, 46.11% were Endodontists (ENs) while 53.8% were BDS or MDS of other specialties (ODs). Most dentists preferred multi-visit retreatment and prescribed antibiotics only in specific cases. Radiovisiography was the most preferred imaging aid. Calcium hydroxide and 3% sodium hypochlorite were favored choices for intracanal medicament and irrigant, respectively. Cold lateral compaction obturation technique was most common. Advanced equipment such as microscopes, loupes, ultrasonics, retreatment files, and thermoplastic obturations were more prevalent among ENs as compared to ODs. Conclusion: This study found some differences in endodontic retreatment practice trends among ENs and other dentists. But overall, most clinicians followed the international norms and are updated in recent advances in materials and techniques used in endodontic retreatment. [ABSTRACT FROM AUTHOR]

Endodontic retreatment and endodontic surgery are therapeutic modalities established upon the failure of primary treatment, constituting the last resort to save the dental element and restore the patient's oral health. The objective of this work was to report a clinical case with an extensive periapical lesion between the roots of teeth 11 and 12 in which multiple endodontic retreatments were performed followed by surgical completion, with a view to resolving an endodontic failure. Initially, teeth 11 and 12 were retreated, using the most recent materials and techniques available. In total, 3 intracanal medication changes were carried out with Bio-C Temp, over a period of 6 months. However, in the last exchange there was the appearance of a fistula in the palatal region, indicating the need for surgical complementation to the established endodontic retreatments. In the 10-month follow-up periapical radiograph, it was possible to observe total regression of the lesion, with integrity of the lamina dura, configuring successful treatment. [ABSTRACT FROM AUTHOR]

Endodontics is the science and art that involves the etiology, prevention, diagnosis, and treatment of pathological changes of the dental pulp and its repercussions in the periapical region and, consequently, in the body. The performance of an endodontic treatment implies a series of phases that, clinically, imposes on the professional basic biological knowledge, clinical experience, appropriate equipment, and instruments, otherwise, the apparently simple treatment can become difficult and often impractical. However, it is perceived that professional conducts, errors in diagnosis and failures in techniques during treatment are factors that can also increase the chances of failures in endodontic treatment. Parendodontic surgery emerges as a safe and appropriate surgical procedure for the treatment of teeth with periapical lesions, which do not respond to conventional endodontic treatment, or when retreatment is not possible to be performed. Parendodontics is a surgical technique that should be considered as a treatment option to solve periapical problems. Such a procedure is an alternative to avoid tooth extractions, being a treatment option when the conservative endodontic procedure has failed. [ABSTRACT FROM AUTHOR]

Purpose This in vitro study aimed to assess the performance of ProTaper Universal Retreatment (PTUR), Reciproc Blue (RB), and XP-endo Shaper (XPS) system in the removal of bioceramic root canal filling. Materials and Methods Forty-five human single-rooted mandibular premolars were prepared up to 30/.04 and filled with Endosequence BC sealer and BC points before being assigned into three groups (n=15). The root canal fillings were removed until reaching pre-determined working length (WL) with PTUR in group 1, RB in group 2, and XPS in group 3. During the removal of the filling material, apically extruded debris was collected in pre-weighed Eppendorf tubes, and operation time was recorded with a digital chronometer. Reaching the WL and maintaining apical patency were evaluated separately. The data were statistically analyzed using Kruskal Wallis and Mann Whitney U tests. Results The mean amount of extruded debris was highest in the PTUR group, although all instruments caused apical extrusion of debris. The mean time for reaching WL was longest for RB and shortest for XPS, with significant differences among the groups (p<0.05). Although the difference was not significant (p=0.799), in the PTUR group the WL was reached in 93.3% of the samples, which was higher than other groups (86.7%). Conclusion All tested systems caused a certain amount of debris extrusion. XPS was associated with less extrusion while regaining more rapid access to the periapical area than PTUR and RB. [ABSTRACT FROM AUTHOR]

Aim: Untreated root canals may have a direct impact on root canal treatment (RCT) outcome. The aim of this case report is to describe the nonsurgical root canal retreatment of two mandibular first molars in a patient's mesial roots that had previously missed middle mesial root canals (MMC). Methodology: A 14-year-old female was referred to the our clinic with the complaint of pain in the posterior areas of the right and left mandibula. During the examination, previous RCTs [teeth 36 (mandibular left first molar) and 46 (mandibular right first molar)] were observed. Besides, these teeth have periradicular lesions in the mesial roots probably due to unsuccessful previous treatment. Nonsurgical retreatment was suggested and accepted. Access cavities were prepared and the unnoticed MMCs were detected at the isthmus connecting both mesiobuccal and mesiolingual canals. All the root canals were shaped with NiTi rotary endodontic files. During the shaping, the root canals were irrigated copiously with NaOCl, EDTA, clorhexidine, and saline solutions under a certain protocol. Calcium hydroxide was used for intracanal dressing. Gutta-percha and a resin-based root canal sealer were used for filling. Coronal restorations of the teeth were completed with a composite resin. Conclusion: At follow-up examinations after 3-, 6-, and 12-months, the teeth were asymptomatic and radiographically showed repair of the lesion. Healing was achieved without any need for further endodontic surgical intervention. [ABSTRACT FROM AUTHOR]

Introduction: The practice of removing root canal fillings with solvent materials is frequently required to help an irrigation solution enter the tubules. The current research was aimed at assessing the antifungal properties specifically the candida albicans of the various solvent materials used for the gutta-percha (GP) material. Materials and Methods: Current research was aimed at as a lab method using the disk diffusion technique where the zone of inhibition (ZOI) was calculated. The materials that were analyzed were: orange oil, xylene, turpentine oil, chloroform, and eucalyptus oil. Candida albicans was the test organism employed in the investigation. The agar plates were covered with approximately 500 μL of the suspension. The sterile and empty disks were impregnated with 10 μL of pure GP solvents. These plates were incubated for one day at room temperature. The ZOI's mean diameters were calculated for all five materials and quantified each solvent's fungicidal activity. For intergroup comparison, ANOVA was utilized. P values < 0.05 were deemed substantial. Results: The maximum inhibition exhibited by the Eucalyptus Oil it was 19.01 ± 1.02 mm. This was followed by Xylene. The other three solvents Chloroform, Orange Oil, and Turpentine Oil exhibited a similar ZOI. When all the solvents were compared there was a significant variance of P < 0.001. However, there were significant variances for the Eucalyptus Oil and the Xylene to all the other solvents P < 0.001. Conclusion: This investigation showed that, in comparison to other solvents, the use of eucalyptus oil considerably reduced the levels of Candida Albicans.

The objectives of this study were to compare the effects of various acid solutions combined with ultrasonics as an aid to remove mineral trioxide aggregate (MTA)-based root canal filling and to assess their effect on the surface topography and microhardness of root canal dentin. Materials and Method: Fifty human permanent single rooted and single canaled freshly extracted teeth were decoronated and sectioned apically to prepare the middle third of root sections of 5 mm length. The canals were prepared in a step-back manner. OrthoMTA was packed throughout the prepared canals. These root sections were incubated for one week and subsequently randomly allocated to five groups (n = 10) according to the OrthoMTA removal method: No treatment (NT); 5% glycolic acid + ultrasonics (5% GA+U); 10% glycolic acid + ultrasonics (10% GA+U); 10% citric acid + ultrasonics (10% CA+U); Distilled water + ultrasonics (DW+U). A 1 mm deep well was created within the coronal end of the set OrthoMTA. Wells were filled with each respective test solution and left for 5 min. Thereafter, further removal of OrthoMTA used a specific ultrasonic tip. Finally, the canals were flushed using 1 mL of the respective test solutions and activated with a Controlled Memory ultrasonic tip for two cycles of 20 s each followed by flushing with 1 mL of distilled water and paper point drying of the canals. Then, specimens were longitudinally split into two halves and examined under a scanning electron microscope (1000×) to assess the residual OrthoMTA and surface topography of root canal dentin. The Vickers surface microhardness of treated radicular dentin was measured using the HMV-2 microhardness tester. Result: Data were analysed using one-way ANOVA followed by Tukey's post hoc test. Significant differences for residual OrthoMTA were observed between (10% GA+U) with (5% GA+U), (10% CA+U), (DW+U) and (NT) (p value < 0.01). In the context of microhardness, (5% GA+U) and (10% GA+U) showed statistically significant difference compared to (NT), (10% CA+U) and (DW+U) (p value < 0.01). Conclusion: 10% GA+U was superior to other tested groups in removing OrthoMTA, but it substantially reduced dentin microhardness. [ABSTRACT FROM AUTHOR]

This study's objective was to compare how well xylene, chloroform, turpentine oil, halothane, and orange oil dissolved materials at three different immersion time intervals. For the investigation. An ISO no. 40 cone and gutta-percha cones with a 0.06 taper were gathered. In each of the tested solvents, five batches of samples were made and submerged for 6, 12, and 18 minutes. To ascertain the process of gutta-percha dissolution in the solvents, the weight before immersion and the weight after immersion in the solvents were measured on a digital analytical scale. Analysis of Variance (ANOVA) and multiple comparisons with Scheffe's test (p 0.05) were used to statistically analyse the data. With xylene, the best solvency capacity was attained. Halothane, orange oil, and chloroform all had comparable dissolving abilities. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to assess and compare the influence of the presence of full-coverage crown on the obturation material removal efficiency of different retreatment file systems. Materials and Methods: Sixty extracted, human, maxillary premolars were accessed, instrumented, and obturated with gutta-percha and AH Plus sealer. The samples were scanned with cone-beam computed tomography and volume of obturating material was measured using ITK-SNAP volumetric software. Samples were divided (n = 30) into with and without all metal full-coverage crown groups. Each group was then subdivided into three subgroups (n = 10) based on retreatment file used (ProTaper URS, HyFlex Remover, and NeoEndo). The volume of remnants of obturating material was remeasured by image segmentation using ITK-SNAP volumetric software. One-way analysis of variance, followed by the Tukey's post hoc test, was used for data analysis, with a significance level of 5%. Results: A significant difference in percentage remnant of obturating material after retreatment file was observed on overall comparison between with (29.84%) and without crown (21.79%) groups (P < 0.05). Each file system removed significantly more obturating material in without crown samples than with crown samples (P < 0.05). The percentage remnant of obturating material after retreatment file use was as follows: ProTaper URS > NeoEndo retreatment file > HyFlex Remover. All file systems showed significantly different (P < 0.05) efficiency in removal of obturating material. Conclusions: None of the retreatment file systems were able to remove obturating material completely. The presence of full-coverage crown negatively impacted the efficiency of retreatment files for the removal of obturating material. HyFlex Remover performed better than NeoEndo which was better than ProTaper URS. [ABSTRACT FROM AUTHOR]

Context: Endodontic retreatment is the first line of treatment in cases of failed primary endodontic treatment. Although associated with challenges such as incomplete removal of obturating material, increased clinical time, and extrusion of apical debris, endodontic retreatment still has considerable success rate in the general population. Aims: The aim of this study was to evaluate and compare the efficacy of TruNatomy, ProTaper retreatment, and RaCe file systems to remove the obturating material, time taken to remove the obturating material, and apical extrusion of debris using cone-beam computed tomography (CBCT). Settings and Design: In vitro study. Subjects and Methods: Forty-five moderately curved mesiobuccal roots of the mandibular molars were instrumented up to #25, 4% taper and obturated with bioceramic sealer and lateral compaction technique. Teeth were divided randomly into three groups (n = 15). Teeth were retreated with TruNatomy, ProTaper retreatment, and RaCe file systems, respectively. Preretreatment and postretreatment CBCT scans were recorded and percentage of obturating material removed was calculated. Time taken to remove the obturating material and apical extrusion of debris was noted. Statistical Analysis Used: Descriptive statistics including percentage, mean, standard deviation, Tukey's post hoc test, Kruskal–Wallis test, and Mann–Whitney Post hoc test were used. Results: The total time needed for the removal of obturating material was comparatively shorter in the RaCe group, followed by the ProTaper retreatment group and TruNatomy group (P < 0.001). TruNatomy files were significantly better in removing the obturating material than the ProTaper retreatment files (P = 0.04). Statically, no difference between RaCe and TruNatomy files was noted. Apically extruded debris was more in the TruNatomy group than in the RaCe and ProTaper retreatment groups (P = 0.01). Conclusions: All tested endodontic files were effective in removal of obturating material, although none could completely remove the filling material and no system could completely eliminate apical extrusion. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to evaluate the effectiveness of photon-induced photoacoustic streaming (PIPS), XP-endo Finisher (XPF), and passive ultrasonic irrigation (PUI) for the removal of root canal filling materials from oval root canals. Background: Various adjunctive irrigation techniques following mechanical preparation have been applied to enhance removal of fillings during root canal retreatment. However, whether there is superiority of one approach over others remains controversial. Methods: Thirty extracted single-rooted teeth with oval-shaped canals were instrumented with the ProTaper Next (PTN) system and obturated with the warm vertical compaction technique. After storage at 37C for 1 month, retreatment was performed with the PTN system up to size X4. The teeth were then randomly assigned into three groups (n = 10) that were, respectively, subjected to supplementary irrigation with different protocols: PIPS, PUI, and XPF, followed by measurement of filling material volumes using high-resolution microcomputed tomography. Results: The PTN preparation resulted in significant reductions in residual filling materials ( p < 0.05), whereas PIPS, PUI, and XPF moderately improved the removal of the remnants ( p > 0.05). The residual filling materials after supplementary irrigation ranged from 0.384 – 0.181 to 0.421 – 0.143 mm3 in oval canals. There was no significant difference in the effectiveness among the PIPS, PUI, and XPF approaches ( p > 0.05). Conclusions: Mechanical preparations are useful for removing most root fillings during retreatment in ovalshaped canals. PIPS can reduce residual root-filling materials to the similar extent as PUI and XPF. [ABSTRACT FROM AUTHOR]

Maxillary central incisor is considered the tooth with least anatomical variations. In literature, the prevalence of single root and single canal in maxillary central incisor has been reported as 100%. Only a handful of case reports suggesting more than one root or one canal are available and are mostly associated with developmental anomalies such as gemination and fusion. This article describes a rare case report of retreatment of a maxillary central incisor with two roots with normal clinical crown which was confirmed by cone-beam computer tomography (CBCT). A 50-year-old Indian male patient presented with pain and discomfort on a root canal-treated anterior tooth. Pulp sensibility testing of left maxillary central incisor was negative. Intraoral periapical digital radiograph revealed an obturated canal with suspected outline of a second root which got confirmed with cone shift technique. The tooth was treated under dental operating microscope during which two canals were located and retreatment was completed. Postobturation, CBCT was performed to study the root and canal morphology. Clinically and radiographically, all the follow-up examinations revealed an asymptomatic tooth without any active periapical lesion. The present case report emphasizes the fact that clinicians should approach each case with an open mind having a thorough knowledge of the normal tooth anatomy and should suspect variations in every case to ensure successful endodontic outcome. [ABSTRACT FROM AUTHOR]

This article describes the management of a root canal‐treated maxillary central incisor displaying a radiographic lateral radiolucency and a sinus tract that persisted irrespective of root canal retreatment following high standards. Endodontic microsurgery was indicated and curettage of the pathologic tissue revealed a calculus‐like material attached to the outer root surface around the exit of a large lateral canal. A non‐conventional approach was chosen: No root‐end resection was conducted. Instead, the calculus was removed and the apical surface was scaled and smoothed, conserving the apical structure. Retrocavities were prepared in both lateral and apical foramens and filled with a bioceramic material. Follow‐up examination showed optimal soft tissue healing. One‐year follow‐up of radiographs revealed healing of the lateral lesion. The lesion was diagnosed as a cyst, with an infected lumen. An exuberant calculus‐like material attached to the external root surface was the most likely cause of the recalcitrant lateral periradicular lesion. [ABSTRACT FROM AUTHOR]

Introduction: The nonsurgical endodontic retreatment (NERT) is the first choice of dental ministration when primary/initial endodontic treatment fails. The present study aimed to investigate the presence of postoperative pain (POP) after NERT in permanent asymptomatic teeth as well as possible factors associated with POP. Materials and Methods: A comprehensive search of literature was performed in Pubmed/MEDLINE, Embase, Scopus and Web of Science databases, up to January 2023; including randomized clinical trials and prospective studies. The risk of bias was assessed with RoB 2.0 and ROBINS-I tools. Subgroups analyses were conducted to evaluate the differences in the incidence or level of POP between the number of visits, the use/not use of solvent, the removal technique of gutta-percha, and the period of POP analysis. Mean differences and confidence intervals (CI) of 95% were used as measures of effect, and meta-regression was used along with subgroup analysis. The certainty of evidence was assessed using GRADE, and the probability value of <0.05 was considered significant. Results: Twenty-four studies were selected, with thirteen included in the meta-analysis. There was a statistical difference between the incidence of POP after 24 h (95% CI, 0.28 to 0.52) and one week (95% CI, 0.02 to 0.13) from the endodontic retreatment (P<0.01). However, there was no statistical difference between different techniques, number of visits and use of solvent (P>0.05) in the same period. In addition, the certainty of evidence was very low. Conclusions: Post-operative pain is a common response to NERT, independent of the retreatment technique(s) applied, number of visits and use of solvent(s); with very low certainty of evidence as well as low risk of bias. Moreover, the current analysis showed a (very) serious risk of inconsistency and imprecision. However, POP was significantly reduced within 1 week of the NERT. [ABSTRACT FROM AUTHOR]

With the development and introduction of new techniques, technological advances and refinement, single session endodontic treatment and retreatment has become a predictable clinical approach. And as an adjunct to endodontic retreatment, photodynamic therapy (PDT) has been widely applied as an aid in covering root canals. The clinical case addresses endodontic retreatment in a single session in a tooth with chronic apical periodontitis with the use of photodynamic therapy and the use of bioceramic sealer Bio-C Sealer. It is concluded that endodontic retreatment in a single session using photodynamic therapy showed good clinical and radiographic results, with no postoperative signs and symptoms and an image suggestive of lesion regression after one year of preservation. [ABSTRACT FROM AUTHOR]

Objective: To assess apical root canal transportation using Mtwo or Reciproc during retreatment of severely curved canals, using a multi-analytical approach. Methods: Forty mesial canals from mandibular molars (Vertucci type IV) were evaluated before and after endodontic retreatment to compare apical transportation with Mtwo retreatment or Reciproc. The systems were used on the same root but alternating the mesial canals. The analyses were performed by micro-computed tomography. Four evaluations were performed: (a) longitudinal transportation, (b) horizontal transportation, (c) variation in the angle of curvature of the canal, and (d) canal-root width ratio. Horizontal transportation and canal-root width ratio were evaluated in 1-, 3-, and 5-mm levels. Results: Longitudinal transportation occurred in all samples, with a mean of 0.13 mm for Mtwo and 0.17 mm for Reciproc. Horizontal transportation increased as distant from the apex was the evaluated level, in mean. However, the transport was not observed in all samples. The mean angle of curvature was 4.16 for Mtwo and 3.03 for Reciproc. Canal-root width decreased as distant from the apex was the evaluated level. No significant differences were observed considering all tested variables, independently of the retreatment system or evaluated level (p > 0.05). Conclusion: Mtwo retreatment and Reciproc presented similar apical transportation (horizontal or vertical). Clinical relevance: Both Mtwo retreatment and Reciproc systems could be considered safe regarding apical transportation. [ABSTRACT FROM AUTHOR]

Introduction: In endodontic retreatment, gutta-percha removal must be done correctly in order to assure a successful outcome following failed procedures. The goal of this study was to compare the effectiveness of stainless-steel hand files with three different nickel-titanium rotary instrument systems for removing guttapercha using ultra-conservative access opening in curved canals. Aim: To compare the efficacy of different rotary instruments for removing obturating material from root canals with Ninja access in mandibular mesiobuccal moderately curved canals measured radiographically using Cone-beam Computed Tomography (CBCT). Materials and Methods: An in-vitro study was conducted in the Conservative and Endodontics department, Karnavati School of Dentistry, Karnavati University, Gandhinagar, Gujarat, India in the time period of June 2022 to July 2022. Forty extracted human mandibular molar teeth were accessed through Ultraconservative opening (Ninja Access). After preparing the root canals, they were sealed using gutta-percha and AH Plus sealer through lateral compaction. The teeth were then stored for one week. The samples were divided into four groups according to the rotary file used: Group I- Hedstrom Files; Group II- Pro taper Universal Retreatment (PTUR) Files; Group III- Neoendo Retreatment Files; Group IV- R-Endo Retreatment. The amount of remaining filling material after the retreatment procedure was checked with CBCT. The statistical analysis was performed using R statistical analysis software version 4.1.0 for windows. Results: In sagittal section, there was significant difference of residual filling material between the four file systems in middle third only (p=0.048) while significant difference was seen only in apical third in the coronal section (p=0.011). However, the three rotary retreatment files left significantly less remnants than Hedström files during removal of the gutta-percha. The time taken for retreatment was significantly higher for Hedström files (398.90±20.717) sec followed by R-endo retreatment files (274.30±14.407). Conclusion: H file was the least effective in removing guttapercha from the canals when compared to the other three file systems. The Neo-Endo rotary retreatment system was faster. [ABSTRACT FROM AUTHOR]

Background: The aim of the study was to compare the efficacy of different irrigation and irrigant activation system used as an adjuvant to retreatment rotary files in removal of gutta-percha and sealer from endodontic retreatment using Micro-CT. Method: 64 extracted permanent maxillary central incisor teeth with single canal, were collected and decoronated to standard length of 16 mm. Instrumentation was done using rotary files and obturation was performed using GuttaCore and AH plus sealer. After setting of sealer, initial removal of filling material was performed using ProTaper universal retreatment files (D1, D2, D3). All 64 sample were randomised into four groups (n = 16) Group1: Endodontic syringe irrigation, Group 2: Passive Ultasonic Irrigation (PUI), Group 3: EndoActivator, and Group 4: EndoVac. Micro-CT scanning was performed after obturation, initial removal of filling material by retreatment file and after using experimental protocols of each group, and volume of remaining filling material was calculated using Dolphin software. Statistical analysis performed with one-way ANOVA followed by Tukey's post hoc. Results: A significant reduction in the volume of residual obturation material were found between each group. PUI was superior to the sonic (EndoActivator), negative pressure irrigation technique (EndoVac) and positive pressure irrigation at the coronal, middle third and apical third of the root canal. However, none of the supplementary techniques were able to completely remove the residual obturation material. Conclusion: PUI and EndoActivator were found better in remaining filling material removal, demonstrating clinically useful as supplementary technique in removing remaining obturation material during endodontic retreatment.

Aim. To assess systematically the available scientific evidence about the efficiency and the adverse effects of different solvents dissolving guttapercha.Materials and methods. The study of publications was produced in the electronic databases such as Google Scholar, PubMed during a systematic review of the literature. Included articles contain information about using solvents during endodontic retreatment and their effectiveness and side effects. The publication date criterion was selected from January 2006 to January 2021.Results. 66 articles were viewed during the review. After analyzing the literature for inclusion criteria, the total number of publications has become 13.Conclusions. According to literature data, the frequency of using essential oils (orange oil, grapefruit oil, eucalyptus oil) to dissolve guttapercha in endodontic practice is increasing due to better biocompatibility and lack of cytotoxicity and carcinogenic effects.

Introduction: In endodontic retreatment, gutta-percha removal must be done correctly in order to assure a successful outcome following failed procedures. The goal of this study was to compare the effectiveness of stainless-steel hand files with three different nickel-titanium rotary instrument systems for removing gutta-percha using ultra-conservative access opening in curved canals. Aim: To compare the efficacy of different rotary instruments for removing obturating material from root canals with Ninja access in mandibular mesiobuccal moderately curved canals measured radiographically using Cone-beam Computed Tomography (CBCT). Materials and Methods: An in-vitro study was conducted in the Conservative and Endodontics department, Karnavati School of Dentistry, Karnavati University, Gandhinagar, Gujarat, India in the time period of June 2022 to July 2022. Forty extracted human mandibular molar teeth were accessed through Ultraconservative opening (Ninja Access). After preparing the root canals, they were sealed using gutta-percha and AH Plus sealer through lateral compaction. The teeth were then stored for one week. The samples were divided into four groups according to the rotary file used: Group I- Hedstrom Files; Group II- Pro taper Universal Retreatment (PTUR) Files; Group III- Neoendo Retreatment Files; Group IV- R-Endo Retreatment. The amount of remaining filling material after the retreatment procedure was checked with CBCT. The statistical analysis was performed using R statistical analysis software version 4.1.0 for windows. Results: In sagittal section, there was significant difference of residual filling material between the four file systems in middle third only (p=0.048) while significant difference was seen only in apical third in the coronal section (p=0.011). However, the three rotary retreatment files left significantly less remnants than Hedström files during removal of the gutta-percha. The time taken for retreatment was significantly higher for Hedström files (398.90±20.717) sec followed by R-endo retreatment files (274.30±14.407). Conclusion: H file was the least effective in removing gutta-percha from the canals when compared to the other three file systems. The Neo-Endo rotary retreatment system was faster.

Objective: Confocal laser scanning microscopy (CLSM) was used to investigate the penetration of endodontic sealers into the dentinal tubules after retreatment using two different obturation techniques. Materials and methods: Thirty mandibular premolars were prepared up to instrument F3 (ProTaper Universal, Dentsply) and filled with Endofill using the single cone technique. The canals were retreated using Mtwo instruments. Reobturation was performed with the Bio-C sealer mixed with a fluorophore dye (Fluo-3) using either the lateral condensation technique (group LC) or the single cone technique (group SC) (n = 15). Teeth were sectioned 2, 4, and 6 mm from the apex and analyzed with CLSM to assess the penetration of the sealer into the canal perimeter and the maximum depth of penetration of the sealer into the dentinal tubules. Data were analyzed using ANOVA and the Student-t and Holm-Sidak tests. Results: In the apical segment, the penetrated perimeter was significantly higher in the LC group than in the SC group (p < 0.05); no significant difference was found in the middle and cervical segments (p > 0.05). In terms of penetration depth, no significant differences were found for any of the segments studied (p > 0.05). Conclusion: The LC technique promoted a higher percentage of canal circumference penetrated by the sealer than the SC technique in the apical segment after endodontic retreatment. Clinical relevance: CLSM demonstrated that the LC technique promoted a higher percentage of canal perimeter penetrated by the Bio-C sealer than the SC technique in the apical segment of mandibular premolars after retreatment. [ABSTRACT FROM AUTHOR]

Aim of the study: to evaluate root filling remnants after secondary root canal treatments (SRCTs) of oval-shaped canals with X-rays and cone beam computed tomography (CBCT). The SRCTs were performed using reciprocating NiTi instruments. Methods: Single-rooted teeth (N = 64) were randomly treated with Reciproc Blue (RB) and filled with AH Plus/single cone (SC group) or AH Plus/Guttafusion (GF group). After seven days of storage in HBSS (Hanks balanced salt solution), Gates Glidden burs #2/3 and RB #25 and #40 were used for the SRCTs. The time to complete the procedure was measured. X-rays and CBCT were used to calculate, respectively, the area and the volume occupied by the remnants in the coronal, middle, and apical thirds of each canal. Environmental scanning electron microscopy (ESEM) and energy dispersive X-ray spectroscopy (EDX) were used for qualitative evaluation and morphology composition of the remnants in sectioned roots. A statistical analysis was performed using Sigma Plot (version 13, IBM, Armonk, NY, USA). The study was designed according to PRILE guidelines. Results: After the SRCTs, the middle thirds of the root canals showed the presence of remnants in both groups, as demonstrated by X-rays and CBCT. The GF group showed a statistically significant higher volume of remnants than the SC Group only in the middle third. The ESEM supported by the EDX revealed the remnant composition by the detection of trace elements of sealer and gutta-percha in all root canals. Conclusion: The study demonstrated that the middle third of root canals is a critical region where remnants were packed and spread in the buccal-lingual sides of canals. ESEM-EDX detected a fine layer of filling remnants in all root thirds, suggesting a larger canal contamination than the X-rays and CBCT examinations revealed. [ABSTRACT FROM AUTHOR]