Quality of Root Canal Fillings and Procedural Errors for In Vivo Studies Prepared in Different Clinical Settings and with Rotary Systems: A Systematic Review.

BACKGROUND This systematic review of the literature aimed to identify published studies and evaluate them on the quality of root canal fillings (RCF) and procedural errors with rotary systems for in vivo studies prepared for different clinical settings. MATERIAL AND METHODS A full literature exploration was conducted in Clarivate Analytics' Web of Science, Elsevier's Scopus, Embase, and PubMed for studies published between January 2020 and March 2024. A manual search was also performed by reviewing the references of selected papers. The following keywords were used: quality of root canal filling(s) OR quality of root canal obturation, root canal obturation OR endodontic treatment, clinical setting (academic, private, governmental), AND/OR procedural errors and rotary instrumentation. RESULTS Sixteen clinical studies were included in this review. The acceptance percentages for obturation length, density, and taper were 76.3%, 74.7%, and 82.5%, respectively, indicating significantly high, good ratios. The overall RCF recorded showed that 68.2% of root canal obturations were considered acceptable. Acceptable rates remained higher than unacceptable rates in academic, hospital, and private settings, and percentages ranged from 65.2% to 93.0%. Only 5 studies reported procedural errors, namely, ledge formation, separated instruments, apical perforation, transportation, lateral perforation, and root/foramen perforation. CONCLUSIONS Using rotary instruments for different root canal treatment steps as instrumentation and obturations is highly recommended. Among different clinical setting and practice, these instruments resulted in a good and acceptable RCF, overall quality performed by those instruments, and few procedural errors.

A laboratory study comparing the static navigation technique using a bur with a conventional freehand technique using ultrasonic tips for the removal of fibre posts.

AIM: There are currently no high-quality studies comparing the static navigation technique with conventional methods of fibre post removal. The aim of this ex vivo study was to compare the effectiveness of fibre post removal between a static navigation technique and a conventional freehand technique using ultrasonics by experienced and inexperienced operators. METHODOLOGY: Forty-eight extracted single-rooted human premolars were root-filled. A fibre post was cemented in all 48 teeth, which were then divided randomly into the following groups: static navigation group using burs; static navigation-ultrasonic group; and non-guided group using ultrasonic tips. The following parameters were evaluated for both experienced operators and inexperienced operators: reaching the gutta-percha root filling successfully, the time required to remove the entire post, the occurrence of lateral root perforations, and the amount of root dentine removed. The Kolmogorov-Smirnov test was used to examine the normality of the data; the anova test was used to compare the significant differences among groups; and Tukey tests were used for all two-by-two comparisons. The significance level was set at 0.05. RESULTS: In the static navigation group, the gutta-percha was reached significantly more frequently than in the non-guided group (p < .05). The static navigation approach required significantly less time than the non-guided approach to reach the gutta-percha (p < .05). The total removal of posts was significantly different between groups (p < .05), but there was no significant difference between experienced and inexperienced operators in the static navigation group (p > .05). More perforations were associated with the non-guided group than with the other two groups. The total mean loss of dentine in the non-guided group in all directions was 0.39 (±0.17) mm, with 0.25 (±0.09) mm for experienced, and 0.42 (±0.16) mm for inexperienced operators. CONCLUSION: When compared to a conventional ultrasonic technique for the removal of fibre posts, the static navigation method using burs resulted in less dentine removal, more rapid access to the gutta-percha root filling, less overall time to remove the posts, and fewer complications. When using static navigation, there was no difference in performance between experienced and inexperienced operators.

Exploring access cavity through non-carious cervical lesions: Impacts on instrumentation, obturation, and fracture resistance in mandibular incisors.

AIM: To compare the effects of Cervical Access Cavity (CervAC) and Traditional Access Cavity (TradAC) on root canal preparation, root canal filling, and fracture resistance in mandibular incisors. METHODOLOGY: Twenty recently extracted and intact mandibular incisors were initially scanned using a micro-CT device. The specimens were anatomically matched to create two groups (n = 10). A wedge-shaped non-carious cervical lesion (NCCL) was created on the buccal aspect of all teeth using a double-faced segmented diamond disc. In group 1, a TradAC was prepared, whilst in group 2, access was created through the simulated NCCL using a round diamond bur 1012. After root canal preparation with Rotate instruments sizes 15/0.04, 20/0.04, and 25/0.04, the teeth were scanned again and evaluated for root canal volume and surface area, static voxels, volume of removed dental tissue, and dentine thickness. After that, the root canals were filled using the single-cone technique, teeth were restored with composite resin, and subsequently rescanned to calculate the volume of filling materials and voids. Then, the restored teeth were subjected to fracture resistance tests using a universal testing machine. Statistical comparisons between groups were performed with the Mann-Whitney test or the Student's t-test, with a statistical significance level of 5%. RESULTS: Statistical comparisons indicated no significant differences between groups in terms of root canal volume, surface area, static voxels, removed root dentine, root canal filling volume, percentage of voids, or fracture resistance load (p > .05). Conversely, teeth prepared with TradAC showed a significantly higher percentage of dental tissue removed from the crown (p = .001) and a greater volume of filling material remnants in the pulp chamber (p < .001) compared to the CervAC group. A significantly lower percentage reduction in dentine thickness was observed only on the mesial aspect of root at Level 1 in TradAC group (p = .008). CONCLUSIONS: CervAC can be considered a viable alternative approach in the presence of NCCL in mandibular incisors.

Intracanal removal and apical extrusion of filling material after retreatment using rotary or reciprocating instruments: A new approach using human cadavers.

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

Post-operative pain in non-surgical root canal treatment after sealer-based obturation versus warm vertical compaction: A randomized clinical trial.

AIM: Post-operative pain may occur after non-surgical root canal treatment (NSRCT). The root filling technique and choice of sealer may be contributing factors. This randomized controlled clinical trial compared post-operative pain and analgesics intake after NSRCT using a sealer-based obturation technique (SBO) with single-cone gutta-percha and calcium silicate sealer (CSS) versus a warm-vertical compaction (WVC) technique with gutta-percha and a resin-based sealer (RBS). METHODOLOGY: This study was designed as a parallel-two arm, double-blind, randomized superiority clinical trial registered at www. CLINICALTRIALS: gov (NCT04753138). Patients referred for NSRCT fulfilling the inclusion criteria participated in this study. Pre-operative periapical radiographs and CBCT scans were taken and numerical rating scale (NRS) pain scores were recorded. Upon completion of canal instrumentation, participants were randomly allocated to either Group SBO: SBO with CSS or Group WVC: Warm-vertical compaction with RBS. Post-operative pain and analgesics intake were recorded at 1, 3 and 7 days after endodontic treatment completion. Non-parametric Mann-Whitney U and Friedman tests and a generalized estimating equation were used to assess differences in pain scores between the groups, within each treatment group at different time points and for correlations, respectively. RESULTS: The study included 195 participants (212 teeth). One participant declined to submit the NRS form. Therefore, 194 participants (211 teeth) were included in the final analysis (99.5% response rate). No statistically significant differences in post-operative pain or analgesic intake existed between the two groups at any time point (p > .05). Age, pre-operative pain, apical diagnosis and post-operative analgesic intake were significantly related to post-operative pain (p < .05). CONCLUSIONS: Sealer-based obturation technique with CSS was associated with similar post-operative pain levels and analgesics intake as WVC with RBS. Regarding post-operative pain, SBO with CSSs may be a suitable clinical alternative.

The efficacy of premixed bioceramic sealers versus standard sealers on root canal treatment outcome, extrusion rate and post-obturation pain: A systematic review and meta-analysis.

BACKGROUND: Limited evidence is available regarding the superior clinical properties of bioceramic sealers comparted with traditional standard sealers. OBJECTIVES: This review aimed to answer the following research questions: 'In healthy patients requiring a root canal treatment (P), what is the efficacy of premixed bioceramic sealers (I) compared with traditional root canal epoxy resin-based sealers (C) in terms of survival, success rates (PICO1) sealer extrusion and resorption (PICO2) post-obturation pain (PICO3) (O)?' METHODS: Authors independently searched three electronic databases: PubMed (including MEDLINE), Web of Science, Embase and Scopus up to 31 October 2023. This was accompanied by both grey literature and manual search. Detailed selection criteria were applied, namely mature permanent teeth requiring root canal treatment, premixed bioceramic sealer with gutta-percha as an intervention group, a standard filling technique as control group and full-text available in English. A random-effect meta-analysis was used to synthesize the body of evidence regarding the use of bioceramic sealers in root canal treatment and their impact on post-obturation pain. Effect sizes were represented as relative risks on a logarithmic scale for binary outcomes and as mean differences for continuous outcomes. RESULTS: A total of 941 articles were identified. Fifteen Comparative clinical studies were finally included. Eleven were randomized clinical trials, and four were prospective clinical trials with control group. The follow-up of these studies was not greater than 2 years. No publication bias was observed in any study. No significant differences were observed between the two groups in terms of survival and success rates. A small non-significant lower risk of extrusion was observed for bioceramics. A small, non-significantly lower post-operative-pain within 24-h was observed when bioceramics were used. DISCUSSION: The majority of current evidence shows inconsistencies in reporting and is of short-term duration. Robust prospective long-term trials are needed in this area to better support future recommendations. CONCLUSION: This systematic review is the first to analyse several clinical outcomes using premixed sealers. Included studies differed in terms of clinical protocol and operator expertise, but reported a similar outcome when comparing bioceramic versus standard sealers. Tooth survival, treatment outcome, post-operative pain and periapical extrusion were similar and presented no significant differences between the two sealer types. REGISTRATION: PROSPERO database (CRD42023449151).

Clinical outcome of non-surgical root canal treatment using different sealers and techniques of obturation in 237 patients: A retrospective study.

OBJECTIVES: The aim of this retrospective study was to compare the clinical results of two root canal sealers and three obturation techniques used for non-surgical root canal treatment. MATERIALS AND METHODS: A total of two hundred eighty-three root canal treated teeth in two hundred thirty-seven patients with minimum a 6-month follow-up was included for this study. The canals were filled with three different modes: 1) cold lateral condensation (CLC) and AH Plus Sealer; 2) continuous wave condensation technique (CWC) and AH Plus Sealer, and 3) sealer-based obturation technique (SBO) and AH Plus Bioceramic Sealer. The treatment outcome was analysed based on clinical signs and symptoms, and periapical radiograph (periapical index, PAI). RESULTS: There were no significant differences in treatment outcome between various sealers and filling techniques applied. The sealer extrusion was found most frequently in the CWC group (60.67%), followed by SBO (59.21%) and CLC (21.19%) with statistically significant differences (p < .05). The initial diagnosis, previous treatment and sealer extrusion (p < .05) were prognostic factors that affected treatment outcome. CONCLUSIONS: Based on the findings of this study, neither the sealer type nor the filling technique affected the treatment success while preoperative diagnosis, previous treatment and sealer extrusion had significant effect on the outcome. CLINICAL RELEVANCE: A bioceramic sealant applied along with the single-cone technique might be considered as an alternative method in root canal obturation.

Assessment of dental students' knowledge and performance of master gutta-percha cone selection and fitting during root canal treatment: a pilot study.

BACKGROUND: Misconceptions should be detected early in dental students' training to improve their clinical performance. Accordingly, this study aimed to assess undergraduate dental students' knowledge and performance of master gutta-percha (GP) cone selection and fitting during clinical endodontic courses at the College of Dentistry, King Saud University. METHODS: Ninety-nine undergraduate dental students completed an online survey about their knowledge of master GP cone selection. Forty-five of these students were observed by faculty members in clinical endodontic courses while they fitted master GP cones during root canal treatments. The observers recorded the details of each student's cone-fitting techniques. The data were analysed using t-tests, one-way analysis of variance, and chi-square tests (p < 0.05). Inter- and intra-observer reliability were tested using Fliess' Kappa. RESULTS SURVEY: All participants had good knowledge of over-extended cone management, while 80.8% knew how to properly manage a short cone. The proper flaring assessment method was selected by 86.9% of the female and 34.2% of the male students, and this difference was statistically significant (p = 0.0001). OBSERVATION: The students labelled the working length on the master GP cone with an indentation in 64.4% of the cases and by bending the cone 35.6% of the time. Of all students, 84.4% encountered an apical stop, and this rate correlated significantly with the length of the cone on the master apical cone radiograph (p = 0.001). Improper shaping of the canal was the most common cause of ill-fitting cones (83.3%), while 16.7% of the students chose the wrong cone size. The final obturation length was adequate in 80% of the cases; 57.8% of the students were helped by instructors. CONCLUSIONS: Most students had the basic knowledge required to solve problems related to the selection of master GP cones. However, in the clinical setting, more than half of the students required the assistance of an instructor to adjust their cone's fit. The presence of an apical stop had the most significant effect on the length of the fitted master GP cone on radiography. The most common cause of ill-fitting master cones was improper shaping of the canal.

Clinical outcomes of nonsurgical root canal treatment using NeoSealer Flo and Endosequence BC Sealer: A retrospective analysis with short-term follow-up.

OBJECTIVES: Sealers are an important component in root canal obturation to provide the seal of the root canal system. In recent years, there has been an increase in the use of hydraulic silicate sealers, commonly referred to as bioceramic sealers, due to their many advantageous properties. NeoSealer Flo (NS; Avalon Biomed USA, Houston TX) is a recently introduced premixed bioceramic sealer. There is limited evidence on its properties and clinical performance. Therefore, the purpose of this study was to evaluate the outcome of root canal treatment using NS in a sealer-based obturation technique. MATERIALS AND METHODS: The records of patients in a private practice between 2017 and 2022 were analyzed to identify both initial and retreatment cases obturated with either EndoSequence BC sealer or NS using sealer-based obturation with a minimum of one-year follow-up. Treatment outcome between NS and BC was compared with chi-square test. Logistic regression was used to identify additional prognostic factors. RESULTS: Six hundred and eighty-seven teeth met the inclusion criteria for the study. The success rate of cases obturated with BC was 94.9% and 96.5% for the cases obturated with NS. No statistically significant differences were found between the two sealer types. Presence of a periapical radiolucency or periapical radiolucency > 5.00 mm were statistically significant prognostic factors. CONCLUSIONS: Endodontic treatment using BC or NS with sealer-based obturation method is a viable treatment option. CLINICAL RELEVANCE: Root canal obturation with bioceramic sealers, such as NeoSealer Flo and Endosequence BC sealer, provide favorable clinical outcomes.

The effect of cone beam computerized tomography voxel size and the presence of root filling on the assessment of middle mesial canals in mandibular molar teeth.

INTRODUCTION: The study aims to compare the detection of the middle mesial canal (MMC) in mandibular molar teeth using cone beam computed tomography (CBCT) with different voxel sizes when the mesiobuccal (MB) and mesiolingual (ML) canals have three distinct phases (unpreparation, preparation and obturation and the removal of the obturation and repreparation). METHODS: Two hundred forty-two extracted human mandibular molars were collected and kept in a physiological saline solution prior to use. 0.2-, 0.28- and 0.35-mm voxel sizes CBCT (n = 242) were performed in three phases (Ph): Ph1, no MB and ML canal preparation or obturation; Ph2, after MB and ML canals preparation and obturation; and Ph3, after the removal of the obturation of MB and ML canals and canals repreparation. Images were analyzed using OnDemand3D® software. After the CBCT acquisition in Ph3, all the samples were clarified to visualize the presence of the MMC directly. A blinded, previously calibrated examiner analyzed all the images. RESULTS: The MMC was detected in 15 of the 242 teeth after the clearing technique. The lowest MMC detection rate was observed at 0.35-mm voxel size regardless of the ML and MB canal condition, while the highest was observed at 0.2-mm voxel size (P < 0.05). There is no statistically significant difference between 0.2-mm and 0.28-mm voxel sizes (P > 0.05). In all voxel sizes, the highest rate of detectability of the MMC was seen in Phase 1, while the lowest was in Phase 2. CONCLUSIONS: It may be appropriate to take a 0.20-mm voxel size CBCT image, especially after the removal of root canal filling. CLINICAL RELEVANCE: An appropriate CBCT voxel size and the absence of root canal filling in the root canal system help to detect the missing MMC.

Effect of the filling technique on the filling removal from oval-shaped canals.

OBJECTIVES: This ex vivo study aimed to evaluate the influence of different filling techniques on the filling removal from oval root canals filled with bioceramic sealer. METHODS: Thirty-six mandibular incisors with single oval canals were filled with bioceramic sealer following the techniques (n = 12): single-cone, modified McSpadden, or continuous wave of condensation, and scanned by micro-computed tomography (micro-CT). The filling was removed using the Clearsonic ultrasound tip and Reciproc system up to the R40 instrument, and the working time was recorded. The teeth were scanned again by micro-CT. Percentage of remnant volume (mm³) of the filling material, dentin thickness, and root canal transportation were measured. The data was analyzed using parametric and non-parametric tests with a significance level of 5%. RESULTS: It took more time to remove the filling material using the continuous wave of condensation technique (p < 0.05), followed by the modified McSpadden and single-cone techniques. There was no difference (p > 0.05) when comparing the percentage of remaining filling material among the three groups, nor did it among the segments of each tooth. There was also no difference in the analysis of dentin thickness and transportation when comparing the groups (p > 0.05). CONCLUSIONS: The filling technique did not influence the amount of remaining filling material, dentin thickness, and transportation. The working time was longer with thermoplastic filling techniques. CLINICAL RELEVANCE: Endodontic retreatment in teeth filled with bioceramic sealers increases with their use. Several techniques are used to fill the root canals, thus, it is important to know whether the filling technique influences the non-surgical endodontic retreatment.

Effectiveness of different supplementary protocols for remaining filling material removal in endodontic reintervention: an integrative review.

The aim of this study was to perform an integrative review to identify the most effective supplementary protocols used after filling material (FM) removal and root canal reinstrumentation, during endodontic reintervention. The literature search was performed on the electronic databases PubMed and Latin American and Caribbean Health Sciences Literature (LILACS), using a combination of specific scientific descriptors. Selection criteria accepted articles published in English, Spanish and Portuguese languages, up to August 2021, involving in vitro and ex vivo studies. After applying the eligibility criteria, 46 articles were included for qualitative analysis. The tool for qualitative analysis of quasi-experimental studies of the Joanna Briggs Institute was used to determine the risk of bias of the included articles. The selected articles provided important data regarding the following supplementary protocols: sonic and ultrasonic activation of the irrigating solution; the use of ultrasonic inserts, XP-endo system instruments, and photon-induced photoacoustic streaming for mechanical debridement; and new devices as GentleWave system, and the self-adjusting file. Overall, all supplementary protocols demonstrated efficacy in removing the remaining FM. The implementation of various supplementary protocols can effectively remove the remaining FM from the root canal walls, although complete removal is not always achieved. However, it was not possible to determine the most effective protocol. Conversely, their association can enhance remaining FM removal. Remaining FM attached to root canal walls hinders proper chemical-mechanical preparation during endodontic reintervention. Supplementary protocols optimize the remaining FM removal, enhancing cleaning and disinfection of root canal.

The use of sonic and ultrasonic activation of endodontic sealer to improve sealer filling quality in the root canal: a scoping review.

This scoping review aimed to map whether the use of sonic and ultrasonic methods to activate the endodontic sealer improves the sealer filling quality in the root canal, considering the bond strength and intratubular penetration to the root dentin as evaluation criteria. The study protocol was prospectively registered and is available online ( https://osf.io/x5fma/ ). Reporting was based on PRISMA Extension for Scoping Reviews. The search was performed in Embase, PubMed, Scopus, and Web of Science. We selected studies without time and language restrictions that used sonic or ultrasonic methods to activate endodontic sealer, whose outcomes were bond strength and intratubular penetration. Three researchers independently selected the articles and collected data. Of 1422 articles, 19 were read in full and 13 studies were included. The vast majority of studies opted for direct activation of the endodontic sealer. The most investigated sealers were the epoxy resin-based sealers, and the ultrasonic activation method was the most explored. For the bond strength outcome, there was a trend toward higher values when the sealer was activated ultrasonically, but the findings seem to be divergent. The sonic activation was not effective for its intended purpose. For the outcome of intratubular penetration, the vast majority of studies indicate that the use of sonic and ultrasonic methods to activate the endodontic sealer is capable of increasing intratubular penetration. The use of sonic and ultrasonic methods to directly activate the endodontic sealer can increase the intratubular penetration of the sealer, but their benefits on the bond strength are uncertain.

Impact of low-fusion gutta-percha cones used in variations of the continuous wave condensation technique with filling sealers based on bioceramic compounds on the quality of root canal filling.

To evaluate the impact on the quality of filling with of low-fusion and conventional gutta-percha cones. Thirty-six maxillary canines were prepared and divided into three groups: I-conventional cone with Downpack at 200 °C at 4 mm from the WL; II-low-fusion cone with Downpack at 100 °C up to 4 mm from the WL; III-low-fusion cone with Downpack at 100 °C up to 7 mm from the WL. Temperature variations were measured in thirds on the external surface of the root. The bond strength was evaluated using the push-out test. The adhesive interface was analyzed by scanning electron microscopy. The bond strength and the temperature variation data were analyzed using analysis of variance and the failure type using the chi-square test. The low-fusion cone group with 7 mm Downpack showed higher bond strength (4.2 ± 2.7) compared with conventional cones (2.8 ± 1.6) and low-fusion cones with 4 mm Downpack (2.9 ± 1.6) (p < 0.05), with occurrence of a higher number of adhesive failures to the filling material and mixed failures. Relative to temperature variation, there was less temperature change in the apical third, in the low-fusion cone with Downpack 7 mm (1.0 ± 1.0) (p < 0.05). The use of low-fusion cones allowed the continuous wave condensation technique to be performed at a lower depth of Downpack at 100 °C at 7 mm, with less heating in the apical third, without compromising the quality of filling. Using gutta-percha cones with low fusion, which permits a lower condensation temperature and reduced Downpack depth, maintains the quality of filling, in order to minimize possible damage to the periapical tissues.

An automated method to analyze root filling voids and gaps using confocal microscopy images.

This study evaluated the feasibility of an automated method to delimit the required area to quantitatively analyze root filling voids and gaps from cross-sectional confocal laser scanning microscopy (CLSM) images. Root canals of maxillary canines were prepared with rotary instruments and filled by lateral compaction technique using gutta-percha and AH Plus sealer. The roots were stored (100% humidity, 37 °C) for a period of 24 h and then transversally sectioned to obtain 2-mm-thick slices from the apical and middle thirds. The areas corresponding to filling materials, gaps, and voids were manually delimited or automatically demarked by ImageJ software after converting the images to the RGB color system. Based on manual and automatic delimitations, the percentages of voids and gaps were calculated. Data of voids and gaps between middle and apical thirds were individually compared by paired t-test. Pearson`s correlation test was used to assess the correlation of data between the methods. Irrespective of the method of area delimitation, no difference was observed between the root thirds for both voids and gaps, while the p-values calculated for each method were similar. Almost perfect correlations between the methods were observed for both outcomes. The proposed method to automatically delimit the areas corresponding to filling material, voids, and gaps appears to be a valid method to facilitate the quantitative analysis of defects in root canal fillings using topographic CSLM images.

Postoperative pain of minimally invasive root canal treatment:a randomized clinical trial.

This randomized clinical trial compared postoperative pain between a minimally invasive (MP) and conventional root canal treatment protocol (CP). A total of 170 mature permanent teeth (either with vital or necrotic pulp), were randomly assigned into two groups. In the CP group, ProTaper Gold (Dentsply Sirona, Ballaigues, Switzerland) and a continuous wave of condensation technique were used, whereas, in the MP group, TruNatomy (Dentsply Sirona), ultrasonic-assisted irrigation (UI), calcium hydroxide, and a sealer-based obturation technique were used. Patients recorded preoperative and postoperative pain using a 0-10 numerical rating scale (NRS) at 4 h, 1, 2, 3, 4, 5, 6, and 7 days after instrumentation and 1 day after canal obturation, respectively. There were no significant differences in pain intensity at any time points assessed between the two groups (p > 0.05). The occurrence of moderate/intense pain after instrumentation was significantly associated with preoperative periapical index (PAI) (p = 0.017) and NRS scores (p < 0.001). Preoperative pulp status (p = 0.009) and NRS score (p = 0.006) were identified as significant factors in the occurrence of moderate/intense pain after obturation. Instrumentation unequivocally reduced pain severity for both groups. The post-endodontic pain associated with the use of MP, combined with UI, Ca(OH)2, and calcium-silicate cement, did not differ from that of CP. Preoperative pain score, PAI, and preoperative pulp status were determined to be prognostic factors for postoperative pain.

Reducing apical voids for intra-canal sealer injection using a modified passive deflation needle.

The aim of the study was to evaluate the ability of a modified passive deflation needle to reduce the apical voids during the intra-canal iRoot SP sealer injection. A modified passive deflation injection needle was designed. Forty 20°-curved and twenty S-shaped single-canal resin block models were allocated into six groups. Each group was mechanically prepared to #25/04 or #25/06 file; then the root canals were injected with iRoot SP sealer using a modified needle or a normal plastic needle. Radiographs were taken to measure the length of apical void in each specimen. Similarly, twenty single-canal extracted premolars were collected and randomly divided into four groups. Each group was prepared to #25/04 or #25/06 file; then the root canals were injected with iRoot SP sealer using a modified needle or a normal plastic needle. Roots were then scanned using micro-computed tomography (micro-CT), and the volume of voids in root canals was analyzed and compared among groups. Statistical analysis demonstrated that the length and the volumetric percentage of voids were much lower in the modified needle group in both resin block root canal models and extract teeth than the normal plastic needle group (P < 0.05). The modified passive deflation needle can efficiently reduce apical voids during the intra-canal iRoot SP sealer injection.

Evaluation of apically extruded debris during root canal filling material removal in teeth with external apical root resorption: a comparison of different obturation techniques.

BACKGROUND: Root canal retreatment is necessary when initial treatment fails. Nickel-titanium systems help remove filling materials; however, some methods can cause canal content extrusion, resulting in inflammation and delayed healing. This study aimed to examine the impact of different preparation techniques and endodontic file systems on apical debris volume to limit material dispersion to periradicular tissues. METHODS: Ninety extracted maxillary incisors were evaluated. Simulated apical root resorption was created by removing the apical 2 mm of the root. The teeth were divided into two groups: one filled with a single cone and the other with cold lateral compaction (CLC). Each group was further divided into three subgroups (n = 15 each): Subgroup 1 used Reciproc R25 for removal and R50 for final preparation; Subgroup 2 used ProTaper Universal Retreatment (PTUR) files D1, D2, and D3 for removal and ProTaper Next X5 for finalization; and Subgroup 3 used VDW.Rotate Retreatment (VDW.RotateR) for removal and VDW.Rotate 50.04 for completion. Debris from retreatment was collected in pre-weighed tubes to determine the amount. The apical extrusion data underwent a two-way analysis of variance. RESULTS: The Reciproc group had a mean extruded debris weight of 0.54 ± 0.24 mg, higher than the PTUR (0.28 ± 0.15 mg) and VDW.RotateR (0.39 ± 0.29 mg) groups (p < 0.05). The single-cone technique (SCT) resulted in a mean debris weight of 0.34 ± 0.23 mg, lower than the CLC technique, which had a mean of 0.46 ± 0.27 mg (p < 0.05). SCT had a shorter retreatment duration (111.12 ± 33.46 s) compared to CLC (176.26 ± 52.26 s) (p < 0.05). CONCLUSION: The Reciproc file system and the CLC obturation technique resulted in greater apical debris extrusion than the other methods. SCT was quicker than CLC. The Reciproc groups are more susceptible to apex extrusion during retreatment.

Evaluation of various obturation techniques with bioceramic sealers in 3D-printed C-shaped canals.

This in vitro study compared various obturation techniques with bioceramic sealers for filling C-shaped 3D-printed replicas. A mandibular molar with a C-shaped root canal with a C1 configuration was obtained. After instrumenting with M3 Pro Gold files (United Dental, Shanghai, China) up to size #30/0.04, a CBCT scan of the tooth was taken. Sixty 3D-printed replicas of the tooth were created. The samples were obturated with EndoSeal TCS sealer (E. TCS; Maruchi, Wonju, Korea) or EndoSeal MTA (E. MTA; Maruchi, Wonju, Korea) (n = 30). The samples in each group were obturated with the following techniques (n = 10): (1) single-cone technique (SC), (2) SC with ultrasonic activation (UA), and (3) cold hydraulic compaction (CHC). Following incubation, the replicas' apical, middle, and coronal thirds were inspected under a digital microscope, and the proportion of filling material and void were calculated. Also, the obturation time and sealer extrusion were recorded. Data were analyzed using ANOVA, LSD post-hoc, and the chi-square tests (α = 0.05). The results indicated that in the apical third, E. TCS-SC, E. TCS-UA, and E. MTA-UA had the lowest void percentage among groups (p < 0.05). In the middle thirds, samples obturated with E. TCS-UA showed a significantly lower void percentage among all groups (p < 0.05). However, in the coronal third, E. TCS-CHC showed the least void percentage (p < 0.05), followed by E. TCS-UA and E. MTA-CHC. The E. TCS-SC and E. TCS-UA were the least time-consuming methods (p < 0.05). Sealer extrusion significantly differed among the groups, with E. MTA-UA and E. TCS-UA showing higher incidence (p = 0.019). It was concluded that E. TCS-UA was the most convenient obturation technique. However, care must be taken when obturating the canals with high flow and ultrasonic activation near the vital anatomical landmarks.

A novel simplified approach for endodontic retrograde surgery in short single-rooted teeth.

BACKGROUND: High technical thresholds, long operative times, and the need for expensive and specialized equipment impede the widespread adoption of endodontic microsurgery in many developing countries. This study aimed to compare the effects of a simplified, cost-effective, and time-efficient surgical approach involving orthograde obturation using biological ceramic material greater than 6 mm combined with apicoectomy for single-rooted teeth with short lengths with those of the conventional and current standard methods. MATERIALS AND METHODS: Forty-five premolars equally categorized into three groups: conventional surgery group, standard surgery group, and modified surgery group. A µCT scan was used to calculate the volume of voids. A micro-leakage test and scanning electron microscope (SEM) were performed to assess the sealing effect. Additionally, four cases of chronic periapical periodontitis in the anterior region were selected, and the patients received either the modified approach or the standard surgery for endodontic microsurgery. RESULTS: The volumes of voids in the apical 0-3 mm of the modified group and the standard group were comparable. The micro-leakage test and SEM examination demonstrated closely bonded fillings in the dentinal walls in both the modified surgery group and standard surgery group. The outcomes of the preliminary application of this modified procedure on patients were successful at the time of the follow-up cutoff. CONCLUSIONS: The modified surgery group exhibited similar root canal filling and apical sealing abilities with the standard procedure for single-rooted teeth with short lengths (< 20 mm). The preliminary application of this modified surgical procedure achieved favorable results.