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This study evaluated the reliability of sealer penetration measurement methods used with confocal laser scanning microscopy in correlation with the percentage of residual root filling and examined the effect of residual root‐filling material on dentine penetrability after retreatment. Extracted teeth were randomly divided into different groups according to the obturation sealer used (n = 6); BioRoot RCS; MTA Fillapex; Bio‐C and AH Plus. Root‐filling material was removed before the secondary chemo‐mechanical preparation and obturation using fluorescein labelled AH Plus. Multiple micro‐computed tomography scans were obtained followed by confocal laser scanning microscopy to measure the penetration of the labelled sealer into the dentinal tubules using four different methods. Measuring sealer penetration into radicular dentine using the penetration percentage method was found to be the most reliable. Dentine penetrability during retreatment did not seem to be affected by the type of residual root‐filling material. [ABSTRACT FROM AUTHOR]

The present study evaluated the effectiveness of two reciprocating systems for the removal of root-filling material during endodontic retreatment. One hundred extracted mandibular premolars were prepared and root-filled with gutta-percha and sealer. Root fillings were removed with K-files according to the following techniques: Group A – hand instrumentation; Group B – Endo-Gripper system driven by compressed air; Group C – INTRAmatic 29CH + INTRA-LUX 3LD driven by compressed air; Group D – Endo-Gripper system driven by electric engine; Group E – INTRAmatic 29CH + INTRA-LUX 3LD driven by electric engine. The amount of filling debris on root canal walls was assessed radiographically and analysed using Auto CAD 2000 software. One-wayanova and Duncan’s test revealed statistically significant differences only in the middle third ( P = 0.01); the best results being reached in group D. The apical third displayed the greatest amount of filling material debris, regardless of the technique used. [ABSTRACT FROM AUTHOR]

The purpose of this article was to report a case of untreated apical periodontitis resulting in severe late complications. A patient with an asymptomatic crowned root canal‐treated mandibular molar revealing a radiographic substandard endodontic treatment and a slight periapical radiolucency was made aware of the treatment options and opted for no treatment. The lesion slightly increased in size after 6 years, but the tooth remained asymptomatic and endodontic retreatment was again refused. After 4 more years, the patient presented with an abscess and severe pain, complicated by paraesthesia of the left chin and lip. Radiographic examination revealed that the lesion had increased considerably to involve the mandibular canal. The treatment protocol included long‐term intracanal medication with calcium hydroxide and follow‐ups revealed complete resolution of the periapical radiolucency and the paraesthesia had completely subsided. [ABSTRACT FROM AUTHOR]

The present study aims to assess the efficacy of different irrigation agitation systems in removing calcium silicate‐based sealers from artificial standardised apical grooves. After the root canal instrumentation of 96 teeth, artificial apical grooves were created in half of each root. The samples were divided into two main groups according to the sealer type (AH Plus Jet [APJ] and Sure‐Seal Root™ [SSR]) (n = 48). The root halves were then reassembled and divided into four experimental groups based on the final irrigation technique used: Conventional Syringe Irrigation (CSI), Ultrasonic Irrigant Agitation (UIA), Sonic Agitation (SA) and Manual Dynamic Agitation (MDA). The roots were then dissembled to assess the amount of root canal sealer. UIA significantly removed more of SSR sealer than CSI, MDA and SA while there was no statistical difference between CSI, MDA, SA and UIA groups in the APJ group. None of the irrigation agitation systems used had completely removed the APJ and SSR sealers. However, UIA was more effective in removing SSR sealer from the standardised apical groove than were CSI, MDA and SA. [ABSTRACT FROM AUTHOR]

This study was to determine the effectiveness of diode laser (LI) and ultrasonic (UI)‐activated irrigation with or without a surfactant as adjunct techniques during the retreatment of gutta‐percha and tricalcium silicate‐based sealer (BC) sealer. Forty‐two single‐rooted premolars were instrumented and filled with gutta‐percha and BC sealer, then retreated using NiTi retreatment rotary files. Teeth were randomly divided into three equal groups: Control (manual irrigation), UI and LI groups. Each group was subdivided into 2.5% NaOCl irrigant and ChlorCid™️ Surf subgroups. The amount of material removed following UI and LI was significantly greater than that of manual irrigation (p < 0.0001). However, there was no significant difference between the surfactant subgroups, irrespective of irrigation technique (p = 1.00, p = 0.535, p = 0.805). The use of UI and LI adjuncts to NiTi rotary retreatment techniques showed significant improvement in gutta‐percha with BC sealer removal. However, surfactants had no effect on the efficacy. [ABSTRACT FROM AUTHOR]

This study analysed the bioceramic sealer cleaning ability of two chemo‐mechanical systems in intact and restored teeth. Thirty‐two single‐rooted teeth were used, and half of them restored with a pre‐endodontic composite restoration (PCR). All samples were instrumented with a size 40 Reciproc Blue file and filled with BioRoot RCS. Canals were retreated using the R40 and then R50 Reciproc Blue. The samples were divided into four experimental groups (n = 8): intact teeth/passive ultrasonic irrigation (PUI) (G1), intact teeth/shock wave‐enhanced emission photoacoustic streaming (SWEEPS) (G2), PCR/PUI (G3) and PCR/SWEEPS (G4). The samples were scanned by micro‐CT before and after retreatment, and the volume of remaining filling material was evaluated. The minor percentage of residues were observed in G2, with a volume of 0.447 ± 0.356% of the endodontic space (P < 0.001). The Reciproc/SWEEPS technique showed the better performance in intact teeth compared with PUI technique. Pre‐endodontic restoration did not significantly affect the effectiveness of sealer removal. [ABSTRACT FROM AUTHOR]

The article provides a summary of the fifth and final gathering and lecture of the Australian Endodontic Society (ASE) NSW in 2023. The meeting included a welcome from the president, Dr. Garima Sharma, and reports from the secretary and federal representatives. Dr. Luke Moloney delivered a lecture on endodontic retreatment, discussing factors that influence treatment decisions and presenting evidence on the prognosis of retreatment. The article also mentions upcoming meetings and lectures for 2024. Members can access the lecture recording and other resources through the ASE NSW media library. [Extracted from the article]

We aimed to investigate the in vitro physiologic effects of xylene, chloroform, orange oil and eucalyptus oil solvents for dissolving gutta‐percha on L929 and HOB cell lines; 2.5 and 10 μL mL−1 of these solvents were tested for 24, 48 and 72 h. Gutta‐percha solvents inhibited the proliferation rate of fibroblasts in a dose‐ and time‐dependent manner; however, no inhibition was detected in HOB (evaluated using MTT assay). None of the solvents induced apoptosis/necrosis in HOB cells at ≤2.5 μL mL−1 concentration in contrast to L929 (determined using acridine orange/ethidium bromide dual staining). Each solvent tested reduced the migration rate of both L929 and HOB cell lines in a dose‐dependent manner (evaluated using a scratch assay). Gutta‐percha solvents can damage fibroblast‐rich tissues. Osteoblasts seemed to be more resistant to the tested solvents, and excessive extrusion of solvents from the root canal may also damage the periradicular tissues and reduce the ability to repair. [ABSTRACT FROM AUTHOR]

The aim of this study was to present a new technique for plastic carrier removal in retreatment situations. The gutta‐percha technique that uses plastic carrier obturators is one of the most commonly used; however, removing this core is tedious and time‐consuming. Two clinical cases were performed by an expert in the field of endodontics, to expose this technique, in which a conical ultrasonic tip with an active point and a Hëdstrom hand file allowed the removal of the plastic carrier quickly and effectively. The use of magnification is indispensable for a predictable success with this method. [ABSTRACT FROM AUTHOR]

This study assessed the apical transportation using Mani GPR or HyFlex NT during the retreatment of curved root canals. Thirty‐eight roots were analysed using micro‐CT for the comparison of apical transportation produced by two retreatment systems. Longitudinal transportation, horizontal transportation, variation in the canal angle of curvature and variation in the canal/root width ratio were analysed. Longitudinal transportation was frequently observed, regardless of the system used. The canals retreated with Mani GPR showed a significantly higher horizontal transportation at 1 mm from the root apex (P < 0.01) and greater variation of the canal curvature angle (P < 0.01). The canal/root width ratio was similar between groups (P > 0.05). In conclusion, longitudinal transportation occurred more frequently in the mesial canal walls. Mani GPR showed greater horizontal transportation at 1 mm short of the apex, and higher variation of the canal curvature angle compared with HyFlex NT. [ABSTRACT FROM AUTHOR]

This systematic review aimed to appraise the quality of life of patients with restored endodontically treated teeth. The Preferred Reporting Items for Systematic Reviews and Meta‐Analyses guidelines were employed. The specific PEO question was as follows: population: patients who were healthy individuals ≥18 years old and required endodontic treatment; exposure: endodontic treatment with a coronal restoration with at least 6 months in occlusal function; and outcome: quality of life of patients. Databases were searched in conjunction with hand searching of reference lists of endodontic textbooks, endodontic‐related journals, and relevant articles from electronic searching. Six articles met the inclusion criteria. Most studies concluded that non‐surgical root canal therapy improved patients' quality of life. The effect of operator type yielded conflicting results. Only one paper compared endodontic treatment with implant placement, and it showed similar patient‐centric outcome with a high level of patient satisfaction. Current research is still limited, and further studies are warranted. [ABSTRACT FROM AUTHOR]

This CBCT‐based study analysed morphometric relationships in Mesio‐Buccal (MB) roots of maxillary first molars (MFM). 133 MFM with two MB canals were assessed and classified using Vertucci's classification. MB roots' length and MB1‐MB2 canals inter‐orifice distances (IOD) were noted. The data were analysed using SPSS software. The most frequently present canal was type IV (59.4%) followed by type II (40.6%). Mean MB roots' length for canals exhibiting type IV was 9.26 ± 0.21 mm and of those exhibiting type II was 12.8 ± 0.42 mm. Statistically significant relationship was found between MB root length and canal type. Mean IOD for type II and type IV canals was 2.4 ± 0.47 and 3.8 ± 0.21 mm, respectively. Statistically significant relationship was found between IOD and canal type. Length of MB root and IOD had a significant association with canal type present in MFM. This knowledge can enhance clinicians' understanding of canal morphology which can increase predictability and success rate of endodontic treatment. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the presence of culturable bacteria, endotoxins (LPS) and lipoteichoic acid (LTA) levels in teeth with normal vital pulp (NVP) with intact crowns (IC) and those with coronal restoration (CR) limited to the enamel level. A total of 20 teeth indicated for endodontic treatment due to prosthetic reasons were selected. Samples were collected from the root canals. The levels of cultivable bacteria, LPS and LTA were assessed. Statistical analyses were performed at significance level set at 5%. None of the teeth presented microbial growth. In the IC group, the LPS levels were limited to the lowest concentration of LPS. On the contrary, higher LPS and LTA levels were detected in teeth with CR. It was concluded that teeth with NVP and IC were negative for bacteria, LPS and LTA; while teeth with CR were positive for bacterial virulence factors. [ABSTRACT FROM AUTHOR]

This report presents a rare case of polymorphous low‐grade adenocarcinoma (PLGA) in the anterior maxilla, mimicking a periapical lesion. A 56‐year‐old male reported with a painless swelling in the maxillary right canine‐premolar region. The patient gave a history of root canal therapy for the same teeth one month ago. On intraoral examination, the involved teeth were restored with ceramic crowns. Radiographic examination revealed inadequate obturation with an ill‐defined radiolucency in the periapical region. 3D cone beam computer tomography (CBCT) revealed erosion of the buccal cortical plate near the apices of the roots. Endodontic re‐treatment was performed on both the teeth. Following this, the lesion was excised and submitted for histopathological analysis wherein it was identified as PLGA. Computerised tomographic (CT) scan and positron emission tomography scan (PET) results showed no regional or distant metastasis. Under general anaesthesia, the teeth were extracted, and wide surgical excision of the anterior maxilla was done till the healthy bone was exposed. Healing was uneventful during the follow‐up period. [ABSTRACT FROM AUTHOR]

This study is aimed to assess the efficacy of different final irrigation agitation techniques on dentin tubule penetration of nanoparticle calcium hydroxide (NCH) dressing. Ninety‐six extracted upper incisors were shaped up to #40file. Then, Four experimental groups were formed according to the final irrigation procedure: conventional needle irrigation (CNI), manual dynamic agitation (MDA), sonic agitation (SA) and ultrasonic irrigant agitation (UIA). According to the intracanal drug used, these groups were divided into two subgroups: calcium hydroxide (CH) and NCH. Prepared CH preparations were labelled with Rhodamine B, and CH or NCH were placed in root canals. In the UIA group, both CH and NCH had the highest penetration depth and percentage compared to the other groups (p < 0.05). The penetration depth and percentage of NCH in the UIA and SA groups were significantly higher than in the CH groups (p < 0.05). UIA is more effective than other groups in increasing dentinal tubule penetration of CH and NCH. [ABSTRACT FROM AUTHOR]

To investigate the efficacy of the supplementary use of a rotary agitation method [XP‐endo Finisher (XPF)] and sonically‐activated irrigation [EndoActivator (EA)], using droplet digital PCR (ddPCR) on reducing the bacterial load in previously root canal treated teeth with apical periodontitis. Twenty patients with post‐treatment apical periodontitis were allocated into two groups according to the irrigation activation method used: XPF and EA group. Total bacterial loads, as well as the amount of Enterococcus faecalis (E. faecalis) were determined before (S1) and after (S2) chemomechanical preparation, and after final irrigation activation (S3) by means of ddPCR. The bacterial copy numbers were compared between groups using the Friedman test (Nonparametric Repeated Measures ANOVA). When the groups were examined in terms of gender, age, number of root canals, periapical index score, sterility control total bacteria (SCTB), S1‐ and S2‐total bacteria copy number, it was found that there was no statistical difference between the XPF group and the EA group (p > 0.05). Subsequent activation (S3) resulted in a significant microbial reduction in both XPF and EA groups, both of which reduced significantly more bacteria than chemomechanical instrumentation (S2) (p < 0.0001). On the contrary, S3‐total bacteria copy number of the EA group was lower than the XPF group (p < 0.0147). There was no statistical difference between the XPF group and the EA group in terms of E. faecalis copy number (p > 0.05). Although both the XPF and the EA optimised the antibacterial efficiency of chemomechanical preparation in previously root canal‐treated teeth with apical periodontitis, a lower total bacterial copy number was achieved with the EA application than the XPF application. [ABSTRACT FROM AUTHOR]

To compare the postoperative pain of continuous rotation and reciprocating movements after pulpectomy of non‐vital primary molars and determine associated risk factors. 146 children aged 4–8 years with one primary molar indicated for pulpectomy were randomly assigned to two equal groups: those instrumented with continuous rotation motion (Hyflex EDM Coltene/Whaledent) and reciprocating motion (Reciproc R25 (VDW)). A 4‐point pain scale was used to assess postoperative pain frequencies, which were compared at different intervals using the Chi‐square test. Postoperative pain risk factors were determined using logistic regression analysis. There was no statistically significant difference between the follow‐ups. Gender, pulp status, and radiographic radiolucency increased the risk of postoperative pain incidence. Postoperative pain likelihood in children with chronic apical periodontitis was 8.72 times that of children with necrotic pulps. Postoperative pain after instrumentation with both kinematics was comparable. Postoperative pain incidence is increased by preoperative pulp condition, radiographic radiolucency, and gender. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the efficiency of Er:YAG laser in translucent fibre post removal. 60 human single‐rooted anterior teeth were divided into three groups (n = 20) according to post diameters (Exacto1‐E1, Exacto2‐E2, Exacto3‐E3) and subdivided according to laser application. Fibre posts were cemented to endodontically treated teeth, and the specimens were sliced with a thickness of 1.0 ± 0.2 mm. Er:YAG laser was applied and the push out bond strength test was performed. Two‐way analysis of variance was used to perform the statistical analysis. Push out bond strengths at apical area were significantly lower in all test groups (p < 0.05). Laser application caused increase in all radicular thirds, but it was significant for E1 and E3 groups. Laser application to the post‐dentine interface enhances the connection between post and dentine. [ABSTRACT FROM AUTHOR]

The function of root canal sealer was to achieve an appropriate three‐dimensional filling effect by filling the root canal and some irregular lumen, thereby inhibiting the residual bacteria. There were many types of sealers, but research to find the most suitable ones was still ongoing. In recent years, researchers had continuously improved the performance of sealers by developing new sealers or adding active ingredients to the sealers. However, most sealers exhibit varying degrees of cytotoxicity and tissue responses, which affect clinical therapy efficacy. This review describes different technical approaches, and recent research progress in the biocompatibility evaluation of root canal sealers and provides brief insights into this field by summarising the performance studies of different root canal sealers. [ABSTRACT FROM AUTHOR]

The purpose of the present review was to examine success, survival and failure following intentional replantation of endodontically treated teeth with existing periapical pathosis and to determine the factors that might affect the outcome of replantation. Clinical trials, longitudinal studies, case series with >10 cases and at least 1‐year follow‐up were included. The average rate of success following intentional replantation was 77.23%. Meta‐analysis revealed the mean weighted survival to be 85.9% (95% CI: 79.6–91.2) Common complications include inflammatory root resorption (0%–27%) and ankylosis (0%–25%). Variables influencing successful outcome include extra alveolar dry time <15 min; root‐end resection (2–3 mm) and cavity preparation (3 mm); manipulation of the tooth using the crown only; and use of an appropriate storage media. The review concludes that intentional replantation is a viable treatment option with acceptable survival rates for endodontically treated teeth with periapical pathosis. [ABSTRACT FROM AUTHOR]

This study aimed to examine the amount of apically extruded debris and time during retreatment with five current file systems, which exhibit various kinematic movements. One hundred upper central incisors were shaped with manual files and filled using the thermoplastic injection method. The root canal fillings in each group (n = 20) were removed using the Genius (GN), ProTaper Next (PTN), Reciproc (RCP) Blue, Tango‐Endo (TE) and Twisted File Adaptive (TFA) file systems. The apically extruded debris was collected in preweighed Eppendorf tubes. Time to reach working length and total time were also recorded. The PTN, RCP Blue and TFA instruments caused significantly less apically extruded debris and shorter total retreatment time than the GN and TE file systems (p < 0.05). The time to reach the working length was the shortest in the PTN group compared to the other groups (p < 0.05). All file systems extruded debris while removing the root canal filling. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the antimicrobial effect of four herbal plants glycolic extracts over mixed‐species biofilm composed of Candida albicans (C. albicans) and another pathogenic bacterium as alternative therapy to be investigated. Four plants extract of Pfaffia paniculata roots; Hamamelis virginiana leaf, Stryphnodendron barbatiman tree bark and Gymnema sylvestre stem and leaves were tested over multi‐species biofilm of C. albicans (ATCC 18804) and Streptococcus mutans (ATCC 35688), Staphylococcus aureus (ATCC 6538), Enterococcus faecalis (ATCC 4083) or Pseudomonas aeruginosa (ATCC 15442) for 5 min and 24 h and colony forming units per millilitre was calculated. The data were analysed using Kruskal–Wallis with Dunn's test (p ≤ 0.05). All tested extracts showed antimicrobial action over the mixed‐species biofilms after 24 h. Some extracts eliminated totally the biofilms. The glycolic extract of P. paniculata, H. virginiana, S. barbatiman and G. sylvestre are effective over mixed‐species biofilms and may be indicated as endodontic irrigant or intracanal medication. [ABSTRACT FROM AUTHOR]

This study aimed to develop a predictive model to screen for undetected vertical root fractures (VRFs) in root canal treated teeth. We included 95 root canal treated teeth with suspected VRFs; 77 for training and 18 for validation. Following clinical and cone‐beam CT parameters were recorded: sex, tooth type, coronal restoration, time interval from completion of endodontic treatment to definitive diagnosis (TI), type of bone loss (BL), apical extent of root filling (AR) and the ratio of root filling diameter to the actual diameter in the coronal (1/3TA) and middle (2/3TA) root thirds. A predictive model p = 1/(1 – e−x) was generated, where x = −7.433 + 1.977BL + 1.479 (2/3TA) + 1.102 AR; the sensitivity and specificity were 0.852 and 0.875 for training and 0.917 and 0.833 for validation. VRF teeth were more likely to have vertical bone loss and overfilled root canals. This model had a high diagnostic efficacy for VRFs. [ABSTRACT FROM AUTHOR]

The article presents an update on the activities of the Western Australia branch of the Australian Society of Endodontology Inc. as of April 2013, including holding a dinner lecture on endodontic retreatment and post-removal featuring Sydney Branch member Tim Castrisos.

The internal topography of the root canal is complex, especially for the mesial root of the permanent first molar. In response to such challenges, enhanced irrigation protocols have been developed, using laser pulses to agitate fluids and enhance the removal of microbial deposits. The aim of this laboratory study was to assess the effectiveness of laser agitation of sodium hypochlorite in removing multispecies biofilms grown in the mesial root of the permanent first molars. The five agitation groups (N = 12 roots for each) were: 940 nm diode laser (superpulsed mode, 50 μs/pulses at 20 Hz using 20 mJ/pulse); 1064 nm Nd: YAG laser (200 μs/pulse at 20 Hz using 20 mJ/pulse); 2940 nm Er: YAG laser (50 μs/pulse at 15 Hz using a 400/14 conical tip in the SWEEPS protocol, with 20 mJ/pulse); passive ultrasonic agitation at 28 kHz (positive control); and irrigation with a 27‐gauge side vented needle for 2 min per canal (negative control). Biofilm removal was assessed by confocal microscopic imaging of root slices at 1, 4 and 7 mm from the root apex. None of the tested methods were effective in completely eradicating biofilm from the most confined regions of the root canal system. The greatest challenge was cleaning the isthmus regions. There was a positive correlation between canal cleaning and isthmus cleaning, suggesting that increased effectiveness in cleaning root canal walls is associated with more effective isthmus cleaning. Wider and narrow isthmuses were cleaned better than long and narrow isthmuses. [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]

This study aimed to determine the intraradicular microbiota of previously root canal‐treated teeth with apical periodontitis and to investigate the antibacterial effectiveness of different intracanal medicaments. Sixteen patients with post‐treatment apical periodontitis were allocated into two groups according to the intracanal medicament used: calcium hydroxide (CH) and 2% chlorhexidine gluconate gel (CHX) group. Total bacterial loads, as well as the amount of Enterococcus faecalis (E. faecalis) were determined before (S1) and after (S2) chemomechanical preparation and finally, after intracanal medication (S3) by means of ddPCR. The unpaired t test was used to compare parametric. S3‐total bacteria copy number of the CH group was lower than the CHX group (p < 0.05). There was no statistical difference between the CHX‐ and the CH groups in terms of E.faecalis copy number (p > 0.05). But in terms of total bacteria, CH is better than CHX. Consequently, CH can be used to optimise the antibacterial efficiency of chemomechanical preparation in previously root canal‐treated teeth with apical periodontitis. [ABSTRACT FROM AUTHOR]

Fractal analysis (FA) is a quantitative, objective and non‐invasive method that facilitates the characterisation of the tissue architecture. This study aims to compare the periapical healing at 1‐year follow‐up by evaluating newly generated trabecular bone with FA after Mineral trioxide aggregate (MTA) plug and regenerative endodontic treatment (RET). A total of 55 asymptomatic teeth with a single‐canal, open apex and periapical lesion, treated with MTA plug or RET, were evaluated retrospectively. After considering the inclusion/exclusion criteria, FA was conducted on 30 periapical images using the box‐counting method. In both groups, a significant decrease was observed in the periapical lesion size at 1‐year follow‐up (p < 0.01). However, there was no significant difference between the MTA plug and RET (p > 0.01). Significantly higher fractal dimension values were detected at 1‐year follow‐up in both MTA plug and RET cases (p < 0.01). However, the difference was not significant between the groups (p > 0.01). Both procedures seem to improve periapical healing with a new resistant bone of similar density and complexity. [ABSTRACT FROM AUTHOR]

This study compared the percentage reduction of total obturation materials, gutta‐percha and sealer, using two rotary file systems with/without solvent in retreating C‐shaped root canals and to evaluate the effect of the solvent on instrument separation. C‐shaped root canals were scanned using micro‐CT to identify the root canal morphology and randomly assigned to four groups (n = 12). Retreatment was performed using ProTaper Universal Retreatment (PTUR) or XP‐endo systems with/without solvent. The number of separated instruments were recorded. The samples were scanned pre‐ and post‐retreatment. The percentage reduction of total obturation materials, gutta‐percha and sealer, were calculated. The percentage reduction of gutta‐percha in the PTUR without solvent group was significantly lower than the other groups (P = 0.018). The number of separated instruments in the solvent groups were significantly lower than the no solvent groups (P < 0.05). Solvent increased gutta‐percha removal, when using PTUR and decreased the occurrence of separated instruments for both systems. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the effect of antimicrobial photodynamic therapy (aPDT) with curcumin and riboflavin on three‐week Enterococcus faecalis biofilm. At first the 15‐mm root canals of 65 single rooted extracted human teeth (including maxillary incisors, mandibular and maxillary canines and mandibular premolars) were separated from the crown and were prepared with ProTaper instruments. After autoclave sterilisation, samples were inoculated with E. faecalis suspension, and incubated for three weeks. After ensuring biofilm formation by scanning electron microscopy (SEM) in two teeth, the remaining 63 teeth were randomly divided into seven groups (n = 9): aPDT + curcumin, aPDT + riboflavin, LED, curcumin, riboflavin, 5.25% NaOCl (positive control) and no intervention (negative control). For light source a LED unit with 390–480 nm wavelength (peak of 460 nm), power density of 1000 ± 100 mW cm−2 and mean energy density of 60 J cm−2 was used. The roots were horizontally sectioned into coronal, middle and apical thirds each with 5 mm thicknesses. Dentin chips with equal weight (1 ± 0.005 g) were collected from the root canal walls with Gates Glidden drills and were transferred into microtubes containing 1 mL of sterile saline and vortexed for 30 s. Next, 10 µL of the contents of each tube was serially diluted and eventually, 10 µL of each solution was cultured on BHI agar. The number of colony‐forming units was determined. Data were analysed using the Kruskal–Wallis and Friedman tests. The colony reduction was not significantly different between NaOCl and either riboflavin + LED or Curcumin + LED. The 5.25% NaOCl group showed maximum reduction in colony count, compared with the negative control (P = 0.00). Groups with aPDT with Curcumin + LED (P = 0.005), and with riboflavin + LED (P = 0.011) showed significant reduction in colony count in all three canal thirds (P < 0.05) without any difference with one another. With significant reduction of E. faecalis colony count, aPDT with Curcumin and riboflavin can serve as an adjunct to routine root canal disinfection method. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare the root filling material that remained after retreatment of curved root canals with chloroform and Endosolv R as solvents. The evaluation employed micro-computed tomography ( CT) imaging. Thirty-six extracted molar teeth with curved roots were selected. After preparation with ProTaper rotary instruments, the canals were filled with gutta-percha and AH26 sealer. The teeth were randomly divided into three groups according to solvent used ( n = 12) as follows: group 1: chloroform; group 2: Endosolv R; group 3: no solvent (negative control). Pro Taper Universal Retreatment files were used to remove each root canal filling and then the self-adjusting file was applied for two minutes. Preoperative and postoperative micro- CT images were used to assess the percentage of residual filling material. The mean percentage of residual filling material was quantified. There were no statistically significant differences between the groups in terms of percentage volume of residual root canal filling. [ABSTRACT FROM AUTHOR]

To evaluate the effectiveness of the ProTaper and Mtwo retreatment systems for removal of resin-based obturation techniques during retreatment. A total of 160 maxillary anterior teeth were enlarged to size 30 using ProTaper and Mtwo rotary instruments. Teeth were randomly divided into eight groups. Resilon + Epiphany, gutta-percha + Epiphany, gutta-percha + AH Plus and gutta-percha + Kerr Pulp Canal Sealer ( PCS) combinations were used for obturation. ProTaper and Mtwo retreatment files were used for removal of root canal treatments. After clearing the roots, the teeth were split vertically into halves, and the cleanliness of the canal walls was determined by scanning electron microscopy. Specimens obturated with gutta-percha and Kerr PCS displayed significantly more remnant obturation material than did specimens filled with resin-based obturation materials. Teeth prepared with Mtwo instruments contained significantly more remnant filling material than did teeth prepared with ProTaper. ProTaper files were significantly faster than Mtwo instruments in terms of the mean time of retreatment and time required to reach working length. The Resilon + Epiphany and AH Plus + gutta-percha obturation materials were removed more easily than were the Epiphany + gutta-percha and Kerr PCS + gutta-percha obturation materials. Although ProTaper retreatment files worked faster than did Mtwo retreatment files in terms of removing root canal obturation materials, both retreatment systems are effective, reliable and fast. [ABSTRACT FROM AUTHOR]

In this study, computed tomography (CT) was used to assess three techniques for root canal filling removal. Seventy-five roots of extracted human lower incisors were filled with zinc oxide-eugenol sealer and gutta-percha and separated into three groups before gutta-percha removal (group 1, Gates Glidden burs + K-type hand instrumentation; group 2, K-type reciprocating instrumentation + NSK TEP E16R; group 3, ProTaper rotary instrumentation + NSK NAC E16R). Specimens were CT-scanned before and after filling removal. The mean rate of filling removal was 94.88%. Reciprocating instrumentation was the most effective and manual instrumentation associated with Gates Glidden burs was the least effective technique. Removal rate was significantly different for the three groups according to one-way anova ( P = 0.049). The Tukey test showed a significant difference between groups 1 and 2 ( P = 0.039) only. CT proved to be a reliable method for assessing root filling removal techniques. [ABSTRACT FROM AUTHOR]

This study evaluated the penetration of the irrigant subject to activation after performing retro‐preparation in endodontic microsurgery. Forty mandibular premolars were prepared and filled. Subsequently, 1 mm from the root apex was cut using a multi‐blade bur and the retro‐preparation was performed. In group 1, the retro‐cavity was cleaned with 2 mL of saline and then with 2 mL of 5.25% NaOCl gel mixed with 0.1% Rhodamine B. In group 2, the retro‐cavity was cleaned with 2 mL of saline, 17% EDTA gel was activated ultrasonically for 30 s and 5.25% NaOCl gel was mixed with 0.1% Rhodamine B and activated for 30 s. After 7 days, the roots were cut at 1mm from the apex and the slices were evaluated with confocal laser scanning microscopy. The samples of group 2 showed statistically better results. The activation protocol proposed resulted in enhanced irrigant penetration when compared to the traditional. [ABSTRACT FROM AUTHOR]

Regenerative endodontic treatment (RET) may not be suitable in some necrotic young permanent molars due to coexistent roots with closed and open apices, and/or inadequate apical bleeding in one or more roots. Here, we present a combined treatment approach utilising conventional root canal treatment in the closed‐apex roots and RET on the open‐apex roots of necrotic young molars. The closed‐apex roots of 8 molars received root fillings, and their open‐apex roots were treated with a regenerative endodontic procedure. In another molar, the failed RET on one root was retreated by conventional root canal filling, preserving other revitalised roots. After 4–6 years, all teeth showed periapical healing in the absence of clinical symptoms. The combined conventional and regenerative treatment approach can yield favourable healing outcomes in necrotic, young molar roots with different levels of apical closure. Likewise, failed revitalised roots can be retreated separately with conventional root filling. [ABSTRACT FROM AUTHOR]

This systematic review and meta‐analysis evaluated whether single‐file endodontic instrumentation systems with the reciprocating type of motion are responsible for more debris extrusion than single‐file endodontic instrumentation systems with the full rotational type of motion. Electronic and manual searches were performed following the recommendations of Preferred Reporting Items for Systematic Reviews and Meta‐Analysis – PRISMA. We included studies comparing rotary (Neoniti and/ OneShape) versus reciprocating (WaveOne and/ Reciproc) systems. We evaluated the quality of studies and performed statistical analysis using R‐Project software. Eight studies of high quality were included to perform the meta‐analysis. Subgroup analysis was also done. The overall risk of bias was too low. In conclusion, single‐file reciprocating systems tend to generate more extrusion of debris than single‐file rotary systems. [ABSTRACT FROM AUTHOR]

We investigated the efficiency of Endosonic Blue, EDDY, Ultra X and EndoActivator in removing calcium hydroxide from artificially created apical grooves in root canal walls. In Materials and Methods: A total of 60 single‐root maxillary central incisors, root canals were created and the roots were divided into two longitudinal parts. In the most suitable root piece, artificial grooves were created in the apical section and filled with calcium hydroxide. Calcium hydroxide in the grooves was removed using EDDY, Ultra X, Endosonic Blue or EndoActivator, and the remnants in the grooves were examined under a stereomicroscope. EDDY and Ultra X removed significantly more calcium hydroxide than Endosonic Blue and EndoActivator. The performance of EDDY and Ultra X or Endosonic Blue and EndoActivator was comparable. Therefore, EDDY and Ultra X are more effective than Endosonic Blue and EndoActivator in removing calcium hydroxide from apical grooves in root canal walls. No technique could achieve complete calcium hydroxide removal. [ABSTRACT FROM AUTHOR]