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Background: The aim of this investigation was to assess the apical extrusion potential of sodium hypochlorite (NaOCl) in agarose-embedded mandibular first premolars employing four final agitation procedures. Methods: Based on CBCT confirmation of single oval-shaped canals, one hundred extracted mandibular first premolars were chosen. Using 5.25% NaOCl, the teeth were prepared using the XP Endo Shaper and divided into experimental and control groups. The following were the experimental groups: Group 1 comprised the XP-Endo Finisher, Group 2 the Ultrasonic Activation, Group 3 the Gentle File Finisher Brush, and Group 4 the 27-gauge side-vented needle. To test extrusion, the teeth were placed in a 0.2% agarose gel that contained the pH-sensitive dye m-cresol purple, allowing pixel quantification via ImageJ software (version 1.54i). Results: The XP Endo Finisher featured the most pixels, depicting higher apical extrusion (p < 0.01), followed by the side-vented needle, Gentle File Finisher Brush, and PUI, while the Control Group endured no extrusion. Conclusions: The effective irrigation method for root canal therapy is critical, especially in situations of open apices, resorption, or perforation. According to in vitro experiments, the XP-Endo Finisher has the maximum sodium hypochlorite extrusion, which is determined by parameters such as apical preparation size and irrigation system. [ABSTRACT FROM AUTHOR]

Background: Various stimuli may be extruded from the apical foramen and can harm the periapical tissue. Therefore, this study evaluated the effect of different final irrigation methods on the extrusion of debris and irrigation solution from the apical foramen.Method and Materials: This experimental in-vitro study was performed on 44 mesiobuccal root canals of extracted human maxillary and mandibular teeth with a curvature of less than 25 degrees. First, they were randomly divided into four equal groups, including flat open end, side vented, bevel, and ultrasonic system. Then a cube of standard floral foam, with normal dimensions, was attached to each sample to simulate a partial resistance of periapical tissue. The amount of debris and solution extruded from the apical foramen was measured by weighing these floral foam cubes. Differences in extrusion of debris and detergent solution between experimental groups were analyzed by one-way ANOVA test.Results: Based on the obtained results, in the ultrasonic group, the difference in the weight of the extruded debris with the flat open needle group and the side vent needle group was significant ( P

Background: To determine the amount of apical extrusion between various file systems during the retreatment procedure and to determine the effect of taper on the same. Materials and Method: Seventy mandibular extracted premolars were taken, and preparation was performed using a Woodpecker file (Woodpecker Medical Instrument Co., Ltd., Guilin, China) (25/0.06). The gutta‑percha (GP) was removed from each specimen with H file (#40/0.02) to simulate retreatment in seven groups (n = 10) using ProTaper Next (PTN;Dentsply, Maillefer, Ballaigues, Switzerland) (PTN) (30/0.07), Reciproc (25/0.08), Hyflex CM (30/0.06), Mtwo (30/0.05), Neoendo flex (30/0.04), Neoendo hybrid (30/0.04), and Flexicon file (30/0.06). The specimens were held with the help of a rubber stopper and put in the Eppendorf tube of volume 4 mL (pre‑weighed before retreatment). The debris that was on the root surface of the specimen was washed with distilled water with 1 mL volume, kept in the oven, and then again weighed after 7 days. Results: Apical extrusion was found in the following order: HYFLEX CM (LEAST) < FLEXICON < PROTAPER NEXT < RECIPROC < NEOENDO FLEX < NEOENDO HYBRID < MTWO (HIGHEST). Conclusion: W Hyflex CM and Flexicon files showed lesser extrusion of debris than others. [ABSTRACT FROM AUTHOR]

Abstract Objectives To evaluate the amount of remaining filing material and apical debris extrusion after retreatment using Reciproc Blue, Hyflex EDM and ProTaper Retreatment Files. Materials and methods Thirty-six extracted permanent mandibular first molars with moderately curved mesial roots were selected. Mesiobuccal canals were prepared using the ProTaper Next system up to size X2 and filled using gutta-percha and Adseal sealer via cold lateral compaction. Teeth were randomly divided into three equal groups (n = 12): Group 1: Reciproc Blue (RB)(VDW, Germany), Group 2: Hyflex EDM (HEDM)(Coltene/Whaledent, Switzerland), Group 3: ProTaper Universal Retreatment file system + ProTaper Next file system (PTUR + PTN)( Dentsply Maillefer, Switzerland). Eppendorf tubes were used to collect the apically extruded debris. Cone-beam computed tomographic scans were taken prior to and after retreatment and the volume of remaining filling material was assessed at the coronal, middle and apical levels. Statistical analysis was performed using the Kruskal–Wallis test, Friedman's test and Wilcoxon Sign Rank test. Significance level was set at p value 0.05. Results There were no statistically significant differences among the three groups in the reduction of the volume of the filling material or in the amount of apically extruded debris. Conclusion All the tested filing systems showed similar efficacy in removing the filling material, however, none of them could achieve its complete removal. Apical extrusion of debris occurred with all the systems used with no significant difference between the three groups.

Objectives: To evaluate the amount of remaining filing material and apical debris extrusion after retreatment using Reciproc Blue, Hyflex EDM and ProTaper Retreatment Files. Materials and methods: Thirty-six extracted permanent mandibular first molars with moderately curved mesial roots were selected. Mesiobuccal canals were prepared using the ProTaper Next system up to size X2 and filled using gutta-percha and Adseal sealer via cold lateral compaction. Teeth were randomly divided into three equal groups (n = 12): Group 1: Reciproc Blue (RB)(VDW, Germany), Group 2: Hyflex EDM (HEDM)(Coltene/Whaledent, Switzerland), Group 3: ProTaper Universal Retreatment file system + ProTaper Next file system (PTUR + PTN)(Dentsply Maillefer, Switzerland). Eppendorf tubes were used to collect the apically extruded debris. Cone-beam computed tomographic scans were taken prior to and after retreatment and the volume of remaining filling material was assessed at the coronal, middle and apical levels. Statistical analysis was performed using the Kruskal–Wallis test, Friedman's test and Wilcoxon Sign Rank test. Significance level was set at p value 0.05. Results: There were no statistically significant differences among the three groups in the reduction of the volume of the filling material or in the amount of apically extruded debris. Conclusion: All the tested filing systems showed similar efficacy in removing the filling material, however, none of them could achieve its complete removal. Apical extrusion of debris occurred with all the systems used with no significant difference between the three groups. [ABSTRACT FROM AUTHOR]

Background: This pilot prospective study analysed the clinical use of a new bioceramic premixed CaSi-containing sealer in association with a warm carrier-based technique. Methodology: Healthy patients (n = 38) requiring 40 root canal treatments were enrolled. Periapical X-rays were taken preoperatively, after root canal filling and after 1, 6, and 12 months. Two evaluators assessed the Periapical Index (PAI) and the sealer extrusion. The healing rate and survival rate were also evaluated. Barnard test was used to assess the relationship of each potential prognostic factor with periapical index (PAI) at 12-month follow-up. The significance level was set at 0.05. Results: Root canal treatments (n = 38) were analysed at the end-line (12 months). The total drop-out was 5% (two patients; two teeth). A total of 31 teeth (82%) (PAI 1-2) showed complete healing, while 7 (18%) are still healing. Cumulative survival was 100%. Apical extrusion of the sealers was observed in 18 cases (47%). Of these extrusions, nine (50%) resulted radiographically undetectable after 12 months. Conclusions: The study supports the use of premixed CaSi-based bioceramic sealers in association with carrier-based techniques. Periapical extrusion of the sealer and its radiographic modification or disappearance are possible events reported in the first 12 months. [ABSTRACT FROM AUTHOR]

In various epithelial tissues, the epithelial monolayer acts as a barrier. To fulfill its function, the structural integrity of the epithelium is tightly controlled. When normal epithelial cells detach from the basal substratum and delaminate into the apical lumen, the apically extruded cells undergo apoptosis, which is termed anoikis. In contrast, transformed cells often become resistant to anoikis and able to survive and grow in the apical luminal space, leading to the formation of multilayered structures, which can be observed at the early stage of carcinogenesis. However, the underlying molecular mechanisms still remain elusive. In this study, we first demonstrate that S100A10 and ANXA2 (Annexin A2) accumulate in apically extruded, transformed cells in both various cell culture systems and murine epithelial tissues in vivo. ANXA2 acts upstream of S100A10 accumulation. Knockdown of ANXA2 promotes apoptosis of apically extruded RasV12-transformed cells and suppresses the formation of multilayered epithelia. In addition, the intracellular reactive oxygen species (ROS) are elevated in apically extruded RasV12 cells. Treatment with ROS scavenger Trolox reduces the occurrence of apoptosis of apically extruded ANXA2-knockdown RasV12 cells and restores the formation of multilayered epithelia. Furthermore, ROS-mediated p38MAPK activation is observed in apically delaminated RasV12 cells, and ANXA2 knockdown further enhances the p38MAPK activity. Moreover, the p38MAPK inhibitor promotes the formation of multilayered epithelia of ANXA2-knockdown RasV12 cells. These results indicate that accumulated ANXA2 diminishes the ROS-mediated p38MAPK activation in apically extruded transformed cells, thereby blocking the induction of apoptosis. Hence, ANXA2 can be a potential therapeutic target to prevent multilayered, precancerous lesions. [ABSTRACT FROM AUTHOR]

Background: Endodontic success depends on the complete cleaning and shaping of the root canal. In order to achieve this goal, debris removal is essential. Even with improvements in instrument design, apical debris extrusion continues to be a cause of periradicular inflammation. The current study aimed to compare the amount of apically extruded debris throughout the canal instrumentation with TruNatomy, ProTaper Next, 2Shape rotary systems. Methods: A total of 60 freshly extracted single‑rooted mandibular premolars were used. An access opening was made, and a working length was estimated. The samples were arbitrarily allocated into three groups i.e. Group I: TruNatomy (n = 20), Group II: ProTaper Next (n = 20), Group III: 2Shape (n = 20). During the canal instrumentation, the extruded debris were collected in preweighed Eppendorf tubes. Post-instrumentation, the tubes were placed in a hot air oven at 140°C for five hours. For calculating the dry debris weight, the tube’s pre-instrumentation weight was deducted from the post-instrumentation weight. The data was analysed using one‑way analysis of variance and post hoc Tukey’s test. Results: Extrusion of debris was noted in all the specimens. TruNatomy rotary system showed least debris extrusion in comparison to ProTaper Next and 2Shape (P < 0.05). However, the results were statistically non-significant between ProTaper Next and 2Shape (P > 0.05). Conclusions: It was noted that all instruments apically extruded debris, with TruNatomy system being related to minimum extrusion.

Background: Endodontic success depends on the complete cleaning and shaping of the root canal. In order to achieve this goal, debris removal is essential. Even with improvements in instrument design, apical debris extrusion continues to be a cause of periradicular inflammation. The current study aimed to compare the amount of apically extruded debris throughout the canal instrumentation with TruNatomy, ProTaper Next, 2Shape rotary systems. Methods: A total of 60 freshly extracted single‑rooted mandibular premolars were used. An access opening was made, and a working length was estimated. The samples were arbitrarily allocated into three groups i.e. Group I: TruNatomy (n = 20), Group II: ProTaper Next (n = 20), Group III: 2Shape (n = 20). During the canal instrumentation, the extruded debris were collected in preweighed Eppendorf tubes. Post-instrumentation, the tubes were placed in a hot air oven at 140°C for five hours. For calculating the dry debris weight, the tube’s pre-instrumentation weight was deducted from the post-instrumentation weight. The data was analysed using one‑way analysis of variance and post hoc Tukey’s test. Results: Extrusion of debris was noted in all the specimens. TruNatomy rotary system showed least debris extrusion in comparison to ProTaper Next and 2Shape (P < 0.05). However, the results were statistically non-significant between ProTaper Next and 2Shape (P > 0.05). Conclusions: It was noted that all instruments apically extruded debris, with TruNatomy system being related to minimum extrusion.

The aim of the study was to determine the porosity, dissolution and apical extrusion of AH Plus, MTA Fillapex and EndoSequence BC sealer after immersion in phosphate buffered saline (PBS) using microcomputed tomography (micro-CT). Forty-eight single-rooted teeth were selected. Gutta percha and one of the aforementioned root canal sealers was used for obturation using continuous wave technique. The specimens were scanned after obturation and after seven days of immersion in PBS, by using micro–computed tomography. Porosity, sealer dissolution and apical extrusion were calculated. Statistical analysis was done by using paired t -test, post hoc tukey test and Fischer exact test. Significantly higher percentage of porosity and dissolution of sealer in the apical 4 mm was found for MTA Fillapex and EndoSequence BC sealer than for AH Plus. The incidence of apical extrusion was significantly more in MTA Fillapex (56.25%), followed by EndoSequence BC (31.25%) and AH Plus (0%). None of the three root canal sealers exhibited perfect three-dimensional obturation. The sealers manifested porosity, dissolution and apical extrusion to varying degrees both after obturation and after storage in PBS for 7 days. [ABSTRACT FROM AUTHOR]

Successful outcome of pulp therapy depends on good chemomechanical preparation of the canals. This is completed with the help of various upcoming rotary and hand files. However, during this preparation, there might be an apical extrusion of the debris which may result in postoperative complications. The aim of this study was to evaluate and compare the number of debris apically extruded during canal preparation using two different pediatric rotary file systems and conventional hand file systems in primary teeth. 60 primary maxillary central incisors that were extracted due to trauma or untreated dental caries with no signs of resorption were taken. Canal preparation was executed using three different file systems: Group A: Group A hand K file system, Group B Kedo S Plus, Group C Kedo SG Blue. For each of these files using the Myers and Montgomery model, the pre- and post-weight of the eppendorf tube was assessed to quantify the number of apical debris. The maximum extrusion of apical debris was noticed with the Hand K-file system. The least debris was noticed in the Kedo S Plus file system. Statistical analysis revealed that there were highly significant differences in apical extrusion and debris when comparing hand files and rotary files and also between the two rotary files used. Apical debris collection is an unavoidable outcome of canal instrumentation. Among the file systems compared, rotary files had lesser extrusion when compared to hand files. Among the rotary files, Kedo S plus showed normal extrusion compared to SG Blue. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to assess the amount of apical extrusion of debris after root canal instrumentation with three different reciprocating single endodontic file systems including R-motion, Edge One Fire, and Reciproc Blue. Methods: Forty-five human upper first molars that were extracted for periodontal reason included in the study and randomly assigned among three study groups (n = 15). Reciproc Blue, R-motion, and Edge One files were used to instrument the palatal root. Amount of apical extrusion of debris was assessed using the empty tube model of Myers and Montgomery. Data were analyzed blindly via one-way ANOVA and the Tukey post hoc test using R. Results: There was statistically significant difference among study groups (p < 0 .001). Post hoc test showed nonsignificant difference among Edge One and Reciproc Blue groups (p = 0.106). The difference between R-motion and Reciproc Blue was marginally significant (p = 0.055). Conclusion: Within the limitations of this study, R-Motion showed the most amount of apically extruded debris followed by Reciproc Blue and Edge One.

Background: Endodontic success depends on the complete cleaning and shaping of the root canal. In order to achieve this goal, debris removal is essential. Even with improvements in instrument design, apical debris extrusion continues to be a cause of periradicular inflammation. The current study aimed to compare the amount of apically extruded debris throughout the canal instrumentation with TruNatomy, ProTaper Next, 2Shape rotary systems. Methods: A total of 60 freshly extracted single‑rooted mandibular premolars were use. An access opening was made, and a working length was estimated. The samples were arbitrarily allocated into three groups i.e. Group I: TruNatomy (n = 20), Group II: ProTaper Next (n = 20), Group III: 2Shape (n = 20). During the canal instrumentation, the extruded debris were collected in preweighed Eppendorf tubes. Post-instrumentation, the tubes were placed in a hot air oven at 140°C for five hours. For calculating the dry debris weight, the tube’s pre-instrumentation weight was deducted from the post-instrumentation weight. The data was analysed using one‑way analysis of variance and post hoc Tukey’s test. Results: Extrusion of debris was noted in all the specimens. TruNatomy rotary system showed least debris extrusion in comparison to ProTaper Next and 2Shape (P < 0.05). However, the results were statistically non-significant between ProTaper Next and 2Shape (P > 0.05). Conclusions: It was noted that all instruments apically extruded debris, with TruNatomy system being related to minimum extrusion.

Background: Recently several calcium silicate flowable sealers have been introduced as endodontic materials for the root canal. This clinical study tested the use of a new premixed calcium silicate bioceramic sealer in association with the Thermafil warm carrier-based technique (TF). Epoxy-resin-based sealer with the warm carrier-based technique was the control group. Methodology: Healthy consecutive patients (n = 85) requiring 94 root canal treatments were enrolled in this study and assigned to one filling group (Ceraseal-TF n = 47, AH Plus-TF n = 47) in accordance with operator training and best clinical practice. Periapical X-rays were taken preoperatively, after root canal filling and after 6, 12 and 24 months. Two evaluators blindly assessed the periapical index (PAI) and sealer extrusion in the groups (k = 0.90). Healing rate and survival rate were also evaluated. Chi-square tests was used to analyze significant differences between the groups. Multilevel analysis was performed to evaluate the factors associated with healing status. Results: A total of 89 root canal treatments in 82 patients were analyzed at the end-line (24 months). The total drop-out was 3.6% (3 patients; 5 teeth). A total of 91.1% of healed teeth (PAI 1-2) was observed in Ceraseal-TF, with 88.6% in AH Plus-TF. No significant difference was observed on healing outcome and survival among the two filling groups (p > 0.05). Apical extrusion of the sealers occurred in 17 cases (19.0%). Of these, 6 occurred in Ceraseal-TF (13.3%) and 11 in AH Plus-TF (25.0%). Three Ceraseal extrusions were radiographically undetectable after 24 months. All the AH Plus extrusions did not change during the evaluation time. Conclusions: The combined use of the carrier-based technique and premixed CaSi-based bioceramic sealer showed clinical results comparable with carrier-based technique and epoxy-resin-based sealer. The radiographical disappearance of apically extruded Ceraseal is a possible event in the first 24 months. [ABSTRACT FROM AUTHOR]

Introduction: This study aimed to assess the amount of apical extrusion of debris after root canal instrumentation with three different reciprocating single endodontic file systems including R-motion, Edge One Fire, and Reciproc Blue. Methods: Forty-five human upper first molars that were extracted for periodontal reason included in the study and randomly assigned among three study groups (n= 15). Reciproc Blue, R-motion, and Edge One files were used to instrument the palatal root. Amount of apical extrusion of debris was assessed using the empty tube model of Myers and Montgomery. Data were analyzed blindly via one-way ANOVA and the Tukey post hoc test using R. Results: There was statistically significant difference among study groups (p < 0 .001). Post hoc test showed nonsignificant difference among Edge One and Reciproc Blue groups (p=0.106). The difference between R-motion and Reciproc Blue was marginally significant (p=0.055). Conclusion: Within the limitations of this study, R-Motion showed the most amount of apically extruded debris followed by Reciproc Blue and Edge One. [ABSTRACT FROM AUTHOR]

Background: This pilot prospective study analysed the clinical use of a new bioceramic premixed CaSi-containing sealer in association with a warm carrier-based technique. Methodology: Healthy patients (n = 38) requiring 40 root canal treatments were enrolled. Periapical X-rays were taken preoperatively, after root canal filling and after 1, 6, and 12 months. Two evaluators assessed the Periapical Index (PAI) and the sealer extrusion. The healing rate and survival rate were also evaluated. Barnard test was used to assess the relationship of each potential prognostic factor with periapical index (PAI) at 12-month follow-up. The significance level was set at 0.05. Results: Root canal treatments (n = 38) were analysed at the end-line (12 months). The total drop-out was 5% (two patients; two teeth). A total of 31 teeth (82%) (PAI 1-2) showed complete healing, while 7 (18%) are still healing. Cumulative survival was 100%. Apical extrusion of the sealers was observed in 18 cases (47%). Of these extrusions, nine (50%) resulted radiographically undetectable after 12 months. Conclusions: The study supports the use of premixed CaSi-based bioceramic sealers in association with carrier-based techniques. Periapical extrusion of the sealer and its radiographic modification or disappearance are possible events reported in the first 12 months.

Aim: The aim of the study is to evaluate and compare the quantity of apical debris extrusion from the root canals during biomechanical preparation by various rotary (reciprocating, Protaper Next [PTN] continuous) and manual hand filing system and by means of Crown-Down and Step Back techniques. Materials and Methods: Eighty mature, human mandibular premolars with single canals were randomly divided into four groups of twenty teeth each. Each group was instrumented using one of the four instrumentation systems: Group A: WaveOne, Group B: PTN, Group C: Hand file with Crown Down, Group D: Hand file with Step Back. Extruded debris was collected in preweighed Eppendorf tubes and the extruded irrigant was evaporated. The weight of the dry extruded debris was established by comparing the pre and post-instrumentation weight of Eppendorf tubes for each group. Results: Mean comparison of groups in different instrumentation by ANOVA presented that hand file with Step-Back technique is showed maximum amount of apical extrusion debris and continuous rotary file system showed the minimum amount of extrusion debris (P < 0.001). Conclusions: The current ex vivo study demonstrated reciprocating single file WaveOne and continuous rotary multiple file system lead to significantly less debris extrusion than manual hand file techniques. Reciprocating single file WaveOne extruded more debris than continuous rotary PTN multiple file system. More amount of debris was extruded in the group with Step-Back hand filing than Crown-Down technique.

Aim: The purpose of this research is to compare the amounts of bacteria that are extruded from their apical surfaces during the instrumentation of root canals utilising the K3XF, Protaper Gold, Edge taper Platinum, and Hyflex CM Rotary systems. Materials and methods: Sixty caries free single rooted human maxillary incisor teeth were divided in six groups of ten teeth each. Teeth in each group were instrumented until the working length with the respective rotary file system. The access cavity was made, and the pulp and debris were removed from the canals. On the device for gathering microorganisms, the teeth were mounted. The Fusobacterium Nucleatum (ATCC 25586) was used to infect the root canals, which were then dried at 37 °C for 24 hours. Group I (Control group), no instrumentation was done. Group II used hand K-files, Group III used Protaper gold, Group IV used K3XF, Group V used Edge taper platinum, and Group VI used Hyflex CM rotary file systems. In. The sample was then collected, cultured in Mueller-Hinton agar for 24 hours, and the number of colony-forming units was counted. Statistical analysis: The Kruskal-Wallis nonparametric test and Mann-Whitney U test were applied to determine if significant differences existed among the groups (P< 0.05) Results: Comparing hand K-files to the other four rotary systems, the K3XF file system extruded the fewer number of bacteria. Conclusion: Within the limitations of this study, it can be concluded that all instruments tested produced bacteria from intracanal spaces apically. However, compared to the manual method, engine-driven nickel-titanium devices extruded fewer microorganisms. Comparatively, the K3XF rotary file system extruded less microorganisms than other rotary file systems. [ABSTRACT FROM AUTHOR]

Hypochlorite accidents are relatively rare events. Therefore, there is a lack of precise and accurate reports in the scientific literature that could help clinicians better understand the phenomenon and associated risk factors. This study reported four hypochlorite accidents attributable to 5% NaOCl extrusion in patients who had undergone treatment of the maxillary elements canal treatments. In all cases, the accidents occurred during the irrigation phase and were characterised by intracanal bleeding, ecchymosis, and swelling on the hemiface corresponding to the treated tooth. Antibiotics, paracetamol, NSAID, corticosteroids, and cold or warm compresses for oedema were prescribed to treat the symptoms of the accidents. Significant improvement of symptoms was observed in all patients after 5–6 days. Anatomic risk factors such as apical fenestration, root perforation, and large foramina were identified as possible risk factors for the accidents. After the accidents, clinicians applied endodontic procedures for which there is no scientific evidence to continue endodontic treatments, such as changing the type of irrigant or the irrigation method. Our results suggest that using a standardised approach to document each hypochlorite accident will allow researchers to collect more accurate and detailed data that can subsequently be used to identify potential risk factors and better manage the symptomatology of hypochlorite accidents. [ABSTRACT FROM AUTHOR]

Statement of the Problem: The extrusion of intracanal debris is one of the challenging problems related to almost all root canal preparation systems, which may cause flare-ups and impairment in the healing process. Purpose: This study was conducted to evaluate the amount of apically-extruded debris during root canal preparation using Medin (MEDIN Co., Czech Republic) rotary system compared with two common rotary systems, including ProTaper (Dentsply Maillefer., Switzerland) and RaCe (FKG Dentaire, Switzerland). Materials and Method: In this in vitro study, Sixty mandibular premolars with single canal were randomly assigned to three groups (n=20). The root canals were prepared with Medin, ProTaper, and RaCe rotary instruments based on their manufacturers’ instructions. The debris were collected into pre-weighted Eppendorf tubes. The weight of the extruded debris was calculated by subtracting the pretreatment weight of the vials. Data were analyzed using the Kruskal-Wallis test at a 5% significance level. Results: Medin instrument caused significantly less debris extrusion in comparison with ProTaper and RaCe (p< 0.05). The differences between the ProTaper and RaCe rotary systems were not statistically significant (p= 0.752). Conclusion: Within the limitations of this in vitro study, Medin rotary system produced less apical extrusion than ProTaper and RaCe.

Successful outcome of pulp therapy depends on good chemomechanical preparation of the canals. This is completed with the help of various upcoming rotary and hand files. However, during this preparation, there might be an apical extrusion of the debris which may result in postoperative complications. The aim of this study was to evaluate and compare the number of debris apically extruded during canal preparation using two different pediatric rotary file systems and conventional hand file systems in primary teeth. 60 primary maxillary central incisors that were extracted due to trauma or untreated dental caries with no signs of resorption were taken. Canal preparation was executed using three different file systems: Group A: Group A hand K file system, Group B Kedo S Plus, Group C Kedo SG Blue. For each of these files using the Myers and Montgomery model, the pre- and post-weight of the eppendorf tube was assessed to quantify the number of apical debris. The maximum extrusion of apical debris was noticed with the Hand K-file system. The least debris was noticed in the Kedo S Plus file system. Statistical analysis revealed that there were highly significant differences in apical extrusion and debris when comparing hand files and rotary files and also between the two rotary files used. Apical debris collection is an unavoidable outcome of canal instrumentation. Among the file systems compared, rotary files had lesser extrusion when compared to hand files. Among the rotary files, Kedo S plus showed normal extrusion compared to SG Blue.

Background. This research aimed to investigate and compare the amount of apically extruded debris after root canal preparation using ProTaper Next, ProTaper Gold, and TruNatomy systems. Methods. Forty-five extracted mandibular premolar teeth with single canals with similar lengths were used. The root canals were prepared using ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Gold (Dentsply Maillefer, Ballaigues, Switzerland), or TruNatomy (Dentsply Maillefer, Ballaigues, Switzerland) files. Apically extruded debris during preparation was gathered into preweighed Eppendorf tubes. Then the Eppendorf tubes were incubated at 70°C for five days. The Eppendorf tubes were weighed again to determine their final weight plus the extruded debris. Results. The TRN system resulted in significantly less debris extrusion than the PTN system (P0.05). Conclusion. All the instrumentation systems caused apical extrusion of debris. However, the TRN system resulted in significantly less debris extrusion than the other systems.

Endodontic flare-up or post-operative pain occurs when debris such as necrotic pulp tissue, dentin chips, irrigants, and microorganisms are extruded from the apical foramen intraoperatively into the periradicular tissue during root canal instrumentation. This study compared the amount of apical debris extrusion of the root canal dentin layer after using reciprocating and rotary file systems (WaveOne, ProTaper Next and ProTaper Gold). Sixty extracted human maxillary central incisors with one canal and closed apex were included in the study. Samples were randomly and equally divided into three groups (n = 20) according to the file systems used for preparation of the root canal. Teeth in the WO group were instrumented by WaveOne, while the PTN group were instrumented by ProTaper Next, and teeth samples in the PTG group were cleaned and shaped by ProTaper Gold. The mean apically extruded debris weight in grams was estimated using the modified Myers and Montgomery experimental model. Analysis of variance (ANOVA) test was used for the comparison of debris weight in three groups. Post hoc LSD test was applied for pairwise comparison of debris weight. The α value of significance was 0.05. The WO group had significantly lower mean debris weight than the PTN and PTG groups (p = 0.001). Post hoc pairwise comparison revealed that there was a statistically significant difference in mean debris weight between the WO group and PTN group (0.0215 vs. 0.0341, p = 0.001); and the WO group and PTG group (0.0215 vs. 0.0324, p = 0.003). Root canal preparations with different file systems were associated with apical extrusion of the debris from the root canal dentin layer. However, the WaveOne system resulted in a comparatively lower amount of apical debris layer extrusion than the ProTaper Next and ProTaper Gold rotary file systems. [ABSTRACT FROM AUTHOR]

Aim: The aim of the study is to evaluate and compare the quantity of apical debris extrusion from the root canals during biomechanical preparation by various rotary (reciprocating, Protaper Next [PTN] continuous) and manual hand filing system and by means of Crown-Down and Step Back techniques. Materials and Methods: Eighty mature, human mandibular premolars with single canals were randomly divided into four groups of twenty teeth each. Each group was instrumented using one of the four instrumentation systems: Group A: WaveOne, Group B: PTN, Group C: Hand file with Crown Down, Group D: Hand file with Step Back. Extruded debris was collected in preweighed Eppendorf tubes and the extruded irrigant was evaporated. The weight of the dry extruded debris was established by comparing the pre and post-instrumentation weight of Eppendorf tubes for each group. Results: Mean comparison of groups in different instrumentation by ANOVA presented that hand file with Step-Back technique is showed maximum amount of apical extrusion debris and continuous rotary file system showed the minimum amount of extrusion debris (P < 0.001). Conclusions: The current ex vivo study demonstrated reciprocating single file WaveOne and continuous rotary multiple file system lead to significantly less debris extrusion than manual hand file techniques. Reciprocating single file WaveOne extruded more debris than continuous rotary PTN multiple file system. More amount of debris was extruded in the group with Step-Back hand filing than Crown-Down technique. [ABSTRACT FROM AUTHOR]

Background: Prevention of the debris from extruding to the periapical region is an important aspect to be taken care of as its extrusion can result in pain, periapical inflammation, and delayed healing owing to the presence of highly infective components in the debris. Aim: The present trial was aimed to compare and assess the amount of debris extruded apically using the single-file reciprocating system - WaveOne GOLD and single file rotary system - OneShape in root canal preparations in vitro. Materials and Methods: Thirty mandibular premolars were divided into two groups (15 samples each) prepared with a single-file reciprocating system - WaveOne GOLD and single-file rotary system - OneShape. Debris extruded was collected and then stored in an incubator. The final weight was calculated after obtaining the mean of three consecutive weights obtained for each tooth. The data were compared using the ANOVA and Turkey's post hoc analysis. Results: Debris extrusions were recorded in both groups and analysis revealed statistical differences in weight before and after the instrumentation procedures in both groups. When compared, reciprocating single file – WaveOne GOLD extruded more debris than rotary single file system – OneShape with a P < 0.001. Conclusions: The rotary instrumentation systems extrude lesser debris apically than the reciprocating instrumentation system. The difference found was statistically significant.

Background: Prevention of the debris from extruding to the periapical region is an important aspect to be taken care of as its extrusion can result in pain, periapical inflammation, and delayed healing owing to the presence of highly infective components in the debris. Aim: The present trial was aimed to compare and assess the amount of debris extruded apically using the single-file reciprocating system - WaveOne GOLD and single file rotary system - OneShape in root canal preparations in vitro. Materials and Methods: Thirty mandibular premolars were divided into two groups (15 samples each) prepared with a single-file reciprocating system - WaveOne GOLD and single-file rotary system - OneShape. Debris extruded was collected and then stored in an incubator. The final weight was calculated after obtaining the mean of three consecutive weights obtained for each tooth. The data were compared using the ANOVA and Turkey's post hoc analysis. Results: Debris extrusions were recorded in both groups and analysis revealed statistical differences in weight before and after the instrumentation procedures in both groups. When compared, reciprocating single file – WaveOne GOLD extruded more debris than rotary single file system – OneShape with a P < 0.001. Conclusions: The rotary instrumentation systems extrude lesser debris apically than the reciprocating instrumentation system. The difference found was statistically significant. [ABSTRACT FROM AUTHOR]

Aim: The aim is to compare the apical extrusion of debris during endodontic instrumentation with continuous rotation and reciprocating motion. Materials and Methods: Sixty extracted single-rooted mandibular premolar human teeth were randomly assigned to four groups of 15 teeth each. The canals were then instrumented with the following instrument systems: ProTaper Next (PTN; Dentsply Maillefer, Ballaigues, Switzerland), 2Shape (TS; MicroMega, Besancon, France), Reciproc Blue (RB; VDW, Munich, Germany) and WaveOne Gold (WOG; Dentsply Sirona, Ballaigues, Switzerland). Apically extruded debris during instrumentation was collected into pre-weighed Eppendorf tubes. The Eppendorf tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the pre-instrumentation weight from postinstrumentation weight of the Eppendorf tubes. The data were analyzed using one-way analysis of variance and Tukey's Post hoc tests. Results: Among the instruments tested in the present study, the least amount of extrusion of debris was seen with TS rotary file system (Group IA) followed by RB (Group IIA) and WOG (Group IIB) (P < 0.05), the results, however, were not found to be statistically significant between them. The maximum amount of debris extrusion was observed with PTN (Group IB) with a statistically significant difference when compared to TS, RB, and WOG file system (P > 0.05). Conclusion: All instruments were associated with apical extrusion of debris with TS rotary file system associated minimum extrusion and PTN, resulting in maximum extrusion of debris.

Aim: To evaluate the various kinematic effects of WaveOne Gold reciprocating file system such as 150°° counterclockwise (CCW)–30°° clockwise (CW), 270°° CCW–30°° CW, 360°° CCW–30°° CW, and continuous rotation and the influence of reciprocating and continuous rotary motions of the same file system on the apical extrusion of debris. Materials and Methods: Sixty mandibular premolars were selected. Instrumentation of the canals was done using WaveOne Gold single-file reciprocating systems and grouped into four groups as follows: Group I – 150°° CCW–30°° CW; Group II – 270°° CCW–30°° CW; Group III – 360°° CCW–30°° CW; and Group IV – continuous rotation. The debris extruded through the apical foramen was collected, dried, and weighed, and the raw data thus obtained were subjected to statistical analysis using one-way analysis of variance and least significant difference post hoc tests (P = 0.05). Results: The mean value for the difference of debris extrusion for the four groups was as follows: Group I: 0.0023 ± 0.002 g, Group II: 0.0071 ± 0.0049 g, Group III: 0.0029 ± 0.002 g, and Group IV: 0.0019 ± 0.002 g. The mean value depicted that the manufacturer recommended reciprocation kinematics (Group I) and the continuous rotation (Group IV) extruded less debris than compared to the other two. The intergroup comparison showed that there were significant differences between Group II and III but no significant differences between Group I and IV. Conclusions: Debris extrusion is inevitable. However, the manufacturer prescribed kinematics 150°° CCW–30°° CW and 270°° CCW–30°° CW extruded less debris than compared with the other two groups.

Introduction Root canal filling material may be extruded during retreatment through the apical foramen and cause flare-up or chronic infection. The aim of this study was to compare the apical extrusion of gutta-percha and resilon filling materials during retreatment using hand and rotary instruments. Methods Sixty extracted single-rooted teeth with single, straight canal were selected. Canals were prepared with ProTaper Universal rotary system to a size F2. Two groups (30 teeth in each) were filled with gutta-percha or resilon points, respectively. In both groups teeth were randomly divided into the three subgroups (10 teeth in each), based on the instruments used for retreatment: Hedstrom hand files and two rotary groups-ProTaper and Twisted File instruments. Apical extrusion was detected visually, using a 4-degree scoring system. Mean scores were calculated and analyzed statistically (t-test and ANOVA). The level of significance was set at p < 0.05. Results Under tested experimental conditions, the type of canal filling material did not have significant effect on the results of apical extrusion during retreatment. Significantly more material was extruded in the resilon group when manual, Hedstrom file was used (1.80 ± 1.13) than rotary ProTaper (0.60 ± 0.70) and Twisted File (0.50 ± 0.71). Conclusions The use of a rotary technique is recomended to minimize apical extrusion, especially when resilon obturation material is removed during retreatment.

Statement of the Problem: The extrusion of intracanal debris is one of the challenging problems related to almost all root canal preparation systems, which may cause flare-ups and impairment in the healing process. Purpose: This study was conducted to evaluate the amount of apically-extruded debris during root canal preparation using Medin (MEDIN Co., Czech Republic) rotary system compared with two common rotary systems, including ProTaper (Dentsply Maillefer., Switzerland) and RaCe (FKG Dentaire, Switzerland). Materials and Method: In this in vitro study, Sixty mandibular premolars with single canal were randomly assigned to three groups (n=20). The root canals were prepared with Medin, ProTaper, and RaCe rotary instruments based on their manufacturers’ instructions. The debris were collected into pre-weighted Eppendorf tubes. The weight of the extruded debris was calculated by subtracting the pretreatment weight of the vials. Data were analyzed using the Kruskal-Wallis test at a 5% significance level. Results: Medin instrument caused significantly less debris extrusion in comparison with ProTaper and RaCe (p< 0.05). The differences between the ProTaper and RaCe rotary systems were not statistically significant (p= 0.752). Conclusion: Within the limitations of this in vitro study, Medin rotary system produced less apical extrusion than ProTaper and RaCe. [ABSTRACT FROM AUTHOR]

Hypochlorite accidents are relatively rare events. Therefore, there is a lack of precise and accurate reports in the scientific literature that could help clinicians better understand the phenomenon and associated risk factors. This study reported four hypochlorite accidents attributable to 5% NaOCl extrusion in patients who had undergone treatment of the maxillary elements canal treatments. In all cases, the accidents occurred during the irrigation phase and were characterised by intracanal bleeding, ecchymosis, and swelling on the hemiface corresponding to the treated tooth. Antibiotics, paracetamol, NSAID, corticosteroids, and cold or warm compresses for oedema were prescribed to treat the symptoms of the accidents. Significant improvement of symptoms was observed in all patients after 5–6 days. Anatomic risk factors such as apical fenestration, root perforation, and large foramina were identified as possible risk factors for the accidents. After the accidents, clinicians applied endodontic procedures for which there is no scientific evidence to continue endodontic treatments, such as changing the type of irrigant or the irrigation method. Our results suggest that using a standardised approach to document each hypochlorite accident will allow researchers to collect more accurate and detailed data that can subsequently be used to identify potential risk factors and better manage the symptomatology of hypochlorite accidents.

Background: The success of endodontic treatment depends on the chemomechanical preparation of the tooth. However, the debris produced during canal preparation may extrude through the apical foramen causing postoperative complications. Aim: The aim of this study is to compare the apical debris extrusion during root canal preparation in primary anterior teeth using hand files, rotary ProTaper files, and rotary Kedo-S files. Materials and Methods: Forty-five freshly extracted primary canine with mature apices and a single canal were randomly divided into three groups for instrumentation as follows (n = 15): Group 1: hand files; Group 2: rotary ProTaper files; and Group 3: rotary Kedo-S files. Myers and Montgomery experimental model was used for this study. Apically extruded debris collected in a preweighed Eppendorf tubes was placed in the incubator at 70°C for 5 days. The weight of the debris collected was determined by subtracting the pre- and post-instrumentation weight of the Eppendorf tubes. The data collected were analyzed using the analysis of variance and Tukey's post-hoc tests. Results: Hand files produced more apical debris extrusion than ProTaper and Kedo-S files (P < 0.05) while Kedo-S produced the least (P < 0.05). Conclusion: All instrumentation systems cause apical debris extrusion. Kedo-S produced less apical debris extrusion when compared to the hand files and ProTaper files.

Introduction: A major objective in root canal treatment is to clean the root canal system. During the process, dentine chips, pulp tissue fragments, necrotic tissue, microorganisms, and intracanal irrigants may be extruded through the apical foramen. This in vitro study was conducted to evaluate the apical extrusion of Enterococcus faecalis with One Shape, F360, WaveOne, and Reciproc endodontic single-file systems. Materials and Methods: Seventy-five human single-rooted mandibular premolar teeth were selected. Endodontic access cavities were prepared. Pulp chamber was accessed, and a pure culture of E. faecalis was used to infect the root canals. Vials with rubber stoppers were selected as the test apparatus. Then, the samples were broadly divided into four main groups with a sample size of 15 teeth. Fifteen previously infected teeth were used as controls. All the root canals were instrumented with the size 25 instruments. A total volume of 2 ml of saline was used for each root canal as irrigant. After 24 h, colonies of bacteria were counted using classical bacterial counting technique as colony-forming units. Statistical Analysis: Data were analyzed statistically using Statistical Package for the Social Sciences, version – 21 (IBM Corp., NY) Software for Windows. Data were expressed in its mean and standard deviation. Results: The results indicated that all the four single-file systems tested caused a measurable apical extrusion of debris. Statistically, significant difference was observed between One Shape, F360, WaveOne, and Reciproc in terms of E. faecalis extrusion, P < 0.05. The highest mean value was with One Shape rotary single-file system and the lowest mean value was with WaveOne reciprocating single-file systems. Conclusion: Within the limitations of the present study, it can be concluded that the reciprocating single-file systems extruded less amount of E. faecalis than compared to rotary single-file systems.

Objective: The purpose of this study was to evaluate the effects of size and oscillation frequency of sonic tips on irrigant extrusion during activation. Materials and Methods: Twenty artificial maxillary molar tooth models were used in this study. The palatinal canal of each model was prepared up to final apical size of #40. Each specimen was mounted on a glass vial filled with saline solution to simulate a periapical lesion. The mean initial weights were measured using an analytical balance with 10-5 g accuracy. Then, a series of irrigations were conducted according to the size (15/.02, 25/.04, 35/.04) and operating mode/speed (low, medium, high) of the sonic tips. In control group, the irrigant was delivered by placing the needle tip at the access cavosurface, without the insertion and activation of the sonic tip. The mean weights of apically extruded irrigant were calculated by subtracting the mean initial weights from the final weights of test apparatus. Data were statistically analyzed by the Kruskal-Wallis and Siegel Castellan tests. Results: The use of 15/.02 tips resulted in higher irrigant extrusion than the control only at high speed while the 35/.04 tips only at low speed (p < 0.05). The 25/.04 tips presented higher extrusion than the control with all operating modes (p < 0.05). At high speed mode, both the 15/.02 and 25/.04 tips were associated with higher irrigant extrusion than the 35/.04 tips (p < 0.05). Conclusions: Both the size and oscillation frequency of the sonic tips had significant effects on extrusion during sonically activated irrigation.

Background. The present study aimed to compare the amount of apically extruded debris and irrigants produced by various nickel-titanium instruments. Methods. A total of 100 single-rooted mandibular premolar teeth were root canal treated and prepared for agar gel model. The root canal fillings were removed using Reciproc Blue, ProTaper Next, R-Endo, WaveOne Gold systems or hand instrumentation. The mean weights of apically extruded materials were calculated. Data were statistically analyzed using one-way ANOVA and post hoc Bonferroni tests. Results. Hand instrumentation resulted in significantly more debris and irrigants than other systems (P0.05), while they both produced significantly less apically extruded material than R-Endo system (P

Background. This research aimed to investigate and compare the amount of apically extruded debris after root canal preparation using ProTaper Next, ProTaper Gold, and TruNatomy systems. Methods. Forty-five extracted mandibular premolar teeth with single canals with similar lengths were used. The root canals were prepared using ProTaper Next (Dentsply Maillefer, Ballaigues, Switzerland), ProTaper Gold (Dentsply Maillefer, Ballaigues, Switzerland), or TruNatomy (Dentsply Maillefer, Ballaigues, Switzerland) files. Apically extruded debris during preparation was gathered into preweighed Eppendorf tubes. Then the Eppendorf tubes were incubated at 70°C for five days. The Eppendorf tubes were weighed again to determine their final weight plus the extruded debris. Results. The TRN system resulted in significantly less debris extrusion than the PTN system (P < 0.05). There was no significant difference between the PTN and PTG groups and between the PTG and TRN groups (P > 0.05). Conclusion. All the instrumentation systems caused apical extrusion of debris. However, the TRN system resulted in significantly less debris extrusion than the other systems. [ABSTRACT FROM AUTHOR]

Apoptosis is traditionally considered to be an immunologically silent form of cell death. Multiple mechanisms exist to ensure that apoptosis does not stimulate the immune system to cause inflammation or autoimmunity. Against this expectation, we now report that epithelia are programmed to provoke, rather than suppress, inflammation in response to apoptosis. We found that an acute inflammatory response led by neutrophils occurs in zebrafish and cell culture when apoptotic epithelial cells cannot be expelled from the monolayer by apical extrusion. This reflects an intrinsic circuit where ATP released from apoptotic cells stimulates epithelial cells in the immediate vicinity to produce interleukin-8 (IL-8). Apical extrusion therefore prevents inappropriate epithelial inflammation by physically eliminating apoptotic cells before they can activate this pro-inflammatory circuit. This carries the implication that epithelia may be predisposed to inflammation, elicited by sporadic or induced apoptosis, if apical extrusion is compromised. [Display omitted] • Apoptotic epithelial cells provoke inflammation if extrusion fails • ATP from retained apoptotic cells stimulates P2Y11 receptor on the neighboring cells • Activated P2Y11 stimulates IL-8 production in the neighboring cells • IL-8 recruits neutrophils toward retained apoptotic epithelial cells Duszyc et al. report that apoptotic epithelial cells provoke inflammation if they are not eliminated by apical extrusion. This is driven by paracrine signaling, where ATP from retained apoptotic cells triggers their epithelial neighbors to produce IL-8 and thus recruit neutrophils of the innate immune system. [ABSTRACT FROM AUTHOR]

Organ renewal is governed by the dynamics of cell division, differentiation and loss. To study these dynamics in real time, we present a platform for extended live imaging of the adult Drosophila midgut, a premier genetic model for stem-cell-based organs. A window cut into a living animal allows the midgut to be imaged while intact and physiologically functioning. This approach prolongs imaging sessions to 12–16 hr and yields movies that document cell and tissue dynamics at vivid spatiotemporal resolution. By applying a pipeline for movie processing and analysis, we uncover new and intriguing cell behaviors: that mitotic stem cells dynamically re-orient, that daughter cells use slow kinetics of Notch activation to reach a fate-specifying threshold, and that enterocytes extrude via ratcheted constriction of a junctional ring. By enabling real-time study of midgut phenomena that were previously inaccessible, our platform opens a new realm for dynamic understanding of adult organ renewal.

Background: The success of endodontic treatment depends on the chemomechanical preparation of the tooth. However, the debris produced during canal preparation may extrude through the apical foramen causing postoperative complications. Aim: The aim of this study is to compare the apical debris extrusion during root canal preparation in primary anterior teeth using hand files, rotary ProTaper files, and rotary Kedo-S files. Materials and Methods: Forty-five freshly extracted primary canine with mature apices and a single canal were randomly divided into three groups for instrumentation as follows (n = 15): Group 1: hand files; Group 2: rotary ProTaper files; and Group 3: rotary Kedo-S files. Myers and Montgomery experimental model was used for this study. Apically extruded debris collected in a preweighed Eppendorf tubes was placed in the incubator at 70°C for 5 days. The weight of the debris collected was determined by subtracting the pre- and post-instrumentation weight of the Eppendorf tubes. The data collected were analyzed using the analysis of variance and Tukey's post-hoc tests. Results: Hand files produced more apical debris extrusion than ProTaper and Kedo-S files (P < 0.05) while Kedo-S produced the least (P < 0.05). Conclusion: All instrumentation systems cause apical debris extrusion. Kedo-S produced less apical debris extrusion when compared to the hand files and ProTaper files. [ABSTRACT FROM AUTHOR]

Introduction: During endodontic retreatment apical extrusion of debris in the form of filling materials, necrotic pulp tissues, microorganisms as well as irrigants may lead to post instrumentation pain, inflammation and impaired healing. Aim: The aim of the study was to compare the amount of debris extruded from the apex during retreatment procedures using ProTaper R (PTR; Dentsply Maillefer, Ballaigues, Switzerland) and Endostar RE Re endo rotary system (ERE; Poldent Co. Ltd., Warsaw, Poland) file systems. Materials and Methods: A total of 30 extracted mandibular premolars were prepared and obturated with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany) using warm vertical compaction technique. The teeth were randomly divided into two groups of 15 each for removal of root canal filling material with PTR and ERE files. The Apically Extruded Debris (AED) was collected in preweighed eppendorf tubes. Data were analysed statistically using independent sample t-test. Significance level was established at α=0.05 Results: No significant difference (p=0.701) was found among the groups regarding the amount of AED. AED was more for PTR files as compared to ERE files while PTR files cleaned the canal walls better as compared to ERE. Conclusion: Both retreatment file systems were associated with some degree of debris extrusion from the apex. Though statistically insignificant PTR files extruded more debris than ERE files.

In various epithelial tissues, the epithelial monolayer acts as a barrier. To fulfill its function, the structural integrity of the epithelium is tightly controlled. When normal epithelial cells detach from the basal substratum and delaminate into the apical lumen, the apically extruded cells undergo apoptosis, which is termed anoikis. In contrast, transformed cells often become resistant to anoikis and able to survive and grow in the apical luminal space, leading to the formation of multilayered structures, which can be observed at the early stage of carcinogenesis. However, the underlying molecular mechanisms still remain elusive. In this study, we first demonstrate that S100A10 and ANXA2 (Annexin A2) accumulate in apically extruded, transformed cells in both various cell culture systems and murine epithelial tissues in vivo. ANXA2 acts upstream of S100A10 accumulation. Knockdown of ANXA2 promotes apoptosis of apically extruded RasV12-transformed cells and suppresses the formation of multilayered epithelia. In addition, the intracellular reactive oxygen species (ROS) are elevated in apically extruded RasV12 cells. Treatment with ROS scavenger Trolox reduces the occurrence of apoptosis of apically extruded ANXA2-knockdown RasV12 cells and restores the formation of multilayered epithelia. Furthermore, ROS-mediated p38MAPK activation is observed in apically delaminated RasV12 cells, and ANXA2 knockdown further enhances the p38MAPK activity. Moreover, the p38MAPK inhibitor promotes the formation of multilayered epithelia of ANXA2-knockdown RasV12 cells. These results indicate that accumulated ANXA2 diminishes the ROS-mediated p38MAPK activation in apically extruded transformed cells, thereby blocking the induction of apoptosis. Hence, ANXA2 can be a potential therapeutic target to prevent multilayered, precancerous lesions.

Background : Endodontic success depends on the complete cleaning and shaping of the root canal. In order to achieve this goal, debris removal is essential. Even with improvements in instrument design, apical debris extrusion continues to be a cause of periradicular inflammation. The current study aimed to compare the amount of apically extruded debris throughout the canal instrumentation with TruNatomy, ProTaper Next, 2Shape rotary systems. Methods : A total of 60 freshly extracted single‑rooted mandibular premolars were used. An access opening was made, and a working length was estimated. The samples were arbitrarily allocated into three groups i.e. Group I: TruNatomy (n = 20), Group II: ProTaper Next (n = 20), Group III: 2Shape (n = 20). During the canal instrumentation, the extruded debris were collected in preweighed Eppendorf tubes. Post-instrumentation, the tubes were placed in a hot air oven at 140°C for five hours. For calculating the dry debris weight, the tube's pre-instrumentation weight was deducted from the post-instrumentation weight. The data was analysed using one‑way analysis of variance and post hoc Tukey's test. Results : Extrusion of debris was noted in all the specimens. TruNatomy rotary system showed least debris extrusion in comparison to ProTaper Next and 2Shape (P < 0.05). However, the results were statistically non-significant between ProTaper Next and 2Shape (P > 0.05). Conclusions : It was noted that all instruments apically extruded debris, with TruNatomy system being related to minimum extrusion., Competing Interests: No competing interests were disclosed., (Copyright: © 2023 Rajnekar R et al.)

The aim of this literature review was to analyze all available scientific data on apical extrusion and to identify and associate the possible factors influencing the occurrence of apical extrusion, ranging from the choice of the canal shaping system, the irrigation technique, to the choice of diameter and the apical limit of preparation. A bibliographic search for relevant articles on apical extrusion of debris, irrigants, and bacteria was performed using the following databases: PubMed, Cochrane Library, and ScienceDirect. This search identified articles published between 2010 and 2023 in two languages (French and English). After selective sorting, 25 relevant documents were included. All the studies retained clearly agree on the inherent nature of apical extrusion during endodontic treatment. At the same time, we also understand that the amount of extrusion can be influenced by a number of parameters throughout endodontic therapy. According to this review, despite the undeniable nature of apical extrusion during endodontic therapy, studies with relatable experimental models that approach in vivo conditions are required to establish exploitable conclusions regarding apical extrusion and its prevention., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Laslami et al.)

Background. The present study aimed to compare the amount of apically extruded debris and irrigants produced by various nickel-titanium instruments. Methods. A total of 100 single-rooted mandibular premolar teeth were root canal treated and prepared for agar gel model. The root canal fillings were removed using Reciproc Blue, ProTaper Next, R-Endo, WaveOne Gold systems or hand instrumentation. The mean weights of apically extruded materials were calculated. Data were statistically analyzed using one-way ANOVA and post hoc Bonferroni tests. Results. Hand instrumentation resulted in significantly more debris and irrigants than other systems (P<0.05). The mean amount of apically extruded debris and irrigants produced by Reciproc Blue system was significantly greater than motordriven instruments (P<0.05). No significant difference was detected between ProTaper Next and WaveOne Gold systems (P>0.05), while they both produced significantly less apically extruded material than R-Endo system (P<0.05). Conclusion. All the instruments caused apical extrusion. ProTaper Next and WaveOne Gold systems were associated with significantly less apical extrusion. [ABSTRACT FROM AUTHOR]