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The aim of this study was to assess the temporal evolution of external cervical resorption (ECR) defects using a volumetric quantification method.Cone-beam computed tomographic (CBCT) images of patients diagnosed with ECR who chose not to receive treatment and attended recalls were collected. ECR defects were segmented in CBCT images at baseline and recall, and their volumes were quantified. The volumetric ratio of resorption defects/teeth was calculated. Three-dimensional classification of defects at baseline and recall and the prevalence of root surface perforations ≥1 mm were determined. The Wilcoxon matched pairs signed rank test, chi-square test, and linear regression models were used to analyze the data.Fifteen patients with 20 teeth diagnosed with ECR and an average recall time of 21 months were included. Nine (45%) teeth showed a change in 3-dimensional classification at recall. The volume of resorption defects (P = .0001) and the volumetric ratio of resorption defects/teeth (P = .0001) increased over time. The prevalence of root surface perforations ≥1 mm was higher at recall (n = 17, 85%) compared with baseline (n = 9, 45%) (P = .008). Linear regression models showed significant associations between the resorption defect volume at recall compared with baseline (P .0001; 95% confidence interval, 0.053-0.081) and the volumetric ratio of resorption defects/teeth at recall compared with baseline (P .0001; 95% confidence interval, 0.205-0.356). There was no association between the volume of resorption defects at recall with the length of the recall period, sex, or age (P .05).When left untreated, ECR defects can increase in size and develop more root surface perforations. ECR has a dynamic nature, and its volumetric increase over time does not result from uniform/linear expansion of the defects.

The aim of this systematic review and meta-analysis was to investigate the overall accuracy of deep learning models in detecting periapical radiolucent lesions in dental radiographs, when compared to expert clinicians.Electronic databases of Medline (via PubMed), Embase (via Ovid), Scopus, Google Scholar, and arXiv were searched. Quality of eligible studies was assessed by using Quality Assessment and Diagnostic Accuracy Tool-2 (QUADAS-2). Quantitative analyses were conducted using hierarchical logistic regression for meta-analyses on diagnostic accuracy. Subgroup analyses on different image modalities (periapical radiographs, panoramic radiographs, cone beam computed tomographic images), and on different deep learning tasks (classification, segmentation, object detection) were conducted. Certainty of evidence was assessed by using Grading of Recommendations Assessment, Development and Evaluation (GRADE) system.A total of 932 studies were screened. Eighteen studies were included in the systematic review, out of which six studies were selected for quantitative analyses. Six studies had low risk of bias. Twelve studies had risk of bias. Pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio and diagnostic odds ratio of included studies (all image modalities; all tasks) were 0.925 (95% confidence interval [CI], 0.862-0.960), 0.852 (95% CI, 0.810-0.885), 6.261 (95% CI, 4.717-8.311), 0.087 (95% CI, 0.045-0.168), and 71.692 (95% CI, 29.957-171.565), respectively. No publication bias was detected (Egger's test, p=.82). GRADE showed a 'high' certainty of evidence for the studies included in the meta-analyses.Compared to expert clinicians, deep learning showed highly accurate results in detecting periapical radiolucent lesions in dental radiographs. Most studies had risk of bias. There was a lack of prospective studies.

Background: Biological scaffolds such as blood clot (BC), platelet-rich plasma (PRP), platelet-rich fibrin (PRF), and platelet pellet (PP) are used in regenerative endodontic treatments (RETs). Objective: To systematically and quantitatively evaluate clinical, radiographic, and histologic outcomes of RET studies using different biological scaffolds Methods: MEDLINE, Scopus, Cochrane library, and Embase were searched to identify studies on RET procedures with any scaffold type performed on immature non-vital human teeth, employing any type of biological scaffold. Clinical, radiographic, and histologic outcomes were extracted. Cochrane collaboration risk of bias tool and Newcastle–Ottawa scale were used for quality assessment. Random and fixed model meta-analysis was carried out with 95% confidence interval. Results: Thirty-two studies were included in the qualitative analysis from the primarily retrieved 1895 studies. Only one study had high risk of bias and 71.8% of the studies had high quality. None of the studies reported any histologic findings. Thirty studies were included in meta-analysis. Clinical success rate of RET using either BC, PRP, or PRF was >99%. Furthermore, 32%, 23%, and 27% of BC, PRP, and PRF cases regained vitality, respectively. Periapical healing was seen in 67%, 75%, and 100% of BC, PRP, and PRF cases, respectively. There was no statistical difference between BC, PRP, or PRF regarding clinical success or any radiographic outcomes. Conclusion: There was no significant difference between BC, PRP, and PRF in terms of clinical and radiographic outcomes. When it is difficult or dangerous to induce bleeding in root canals, PRP and PRF may be employed instead.

This systematic review investigates whether different irrigation techniques have different effects on irrigant extrusion from mature tooth apices. Articles published between January 2000 and January 2022 were searched in six electronic databases (MEDLINE, Embase, Google Scholar, Web of Science, Scopus and Cochrane) using appropriate keywords. Overall, 2265 articles were screened by their titles and abstracts. Fifty-six full-text articles were selected based on the inclusion criteria. Of them, 17 in vitro studies were included in the systematic review and meta-analysis. The meta-analysis was conducted using the random-effects inverse variance method. The results showed that the negative pressure technique caused a lesser amount (p = 0.00) and frequency (p = 0.00) of extrusion than the open-ended needle irrigation. Sonic and ultrasonic activation caused less amount of extrusion than both open-ended (p = 0.00 or p = 0.01) and closed-ended needle (p = 0.00) irrigation.

Revitalizing the root canals of previously treated teeth with open apices is appealing to clinicians and patients. However, there are fundamental differences in the microbiome and the microenvironment between a canal with a primary endodontic infection and a canal with a persistent endodontic infection. The aims of this report are to report a case where a previously treated tooth with an open apex and a large apical radiolucency was treated successfully using regenerative endodontic treatment (RET) and to review and critically appraise the literature on procedures and outcomes of RET that result in revitalization of canal(s) in previously treated teeth with open apices. A maxillary central incisor with poor-quality root filling, a large apical radiolucency and an open apex was retreated using RET using platelet-rich fibrin as the scaffold. After 24 months, there was complete healing of the periapical lesion and obvious radiographic signs of apical root closure. Electronic searches were performed in MEDLINE, Scopus and Embase, and the baseline, procedural and outcome data of qualified articles were collected. An assessment tool was developed to rate the quality of evidence reported in these case report/series. Nine articles, three case series and six case reports, with a total of 17 teeth of all types, were included in the reports identified. The age of patients ranged from 7 to 48 years (mean: 19.4 years). The recall period ranged from 12 to 72 months (mean: 29 months). All 17 teeth survived and were functional with healing/healed outcomes. "Apical closure" was the most common radiographic finding regarding root development. The quality of evidence using the new assessment tool was rated "Excellent" in three case reports but only "Fair" in the other six articles. The present case report, as well as the review of the literature, suggests that revitalizing the root canal system of teeth with open apices and post-treatment disease using RET is a potentially valid treatment option. However, more clinical studies with higher levels of evidence and higher quality of evidence are required to confirm the viability of this treatment approach.

To determine and compare the accuracy and efficiency of a dynamic navigation system (DNS) with a freehand (FH) technique when conducting root-end resection in a human cadaver model.Forty roots in cadaver heads were included and divided into two groups: DNS (n = 20) and FH (n = 20). Cone beam computed tomography (CBCT) scans of all teeth were taken. The drilling path and depth were planned virtually to using the X-guide software (X-Nav Technologies, Lansdale, PA, USA). Osteotomy and root-end resection were done under navigation in the DNS group, and freehand under the dental operating microscope in the FH group. Post-operative CBCTs were taken. Linear deviations, angular deflection, time of operation and number of mishaps were compared with determine the accuracy and efficiency. Shapiro-Wilk, one-way ANOVA and Fisher exact tests were used (P 0.05).Linear deviations, angular deflection and operation time were significantly less in the DNS group (P 0.05). The number of mishaps was not different between the two groups (P 0.05). Subgroup analyses revealed that the distance of5 mm from buccal cortical plate was significantly associated with lower accuracy, increased operation time and greater incidence of mishaps in the FH group (P 0.05), but not in the DNS group.The dynamic navigation system was more accurate and more efficient in root-end resection in a cadaver model than the freehand technique. The distance of the roots from the buccal cortical plate had a significant negative impact on the accuracy and efficacy of the root-end resection procedure when using the freehand technique. The dynamic navigation system has the potential to be a safe and reliable technological addition to endodontic microsurgery.

Objective A systematic review and meta-analysis were conducted to determine whether there are postoperative pain differences resulting from rotary and reciprocation engine-driven instrumentation motions in non-surgical endodontic treatment or retreatment at 12, 24, and 48 hours. Methods Four electronic databases (PubMed, Embase, Cochrane Library, and Scopus) were searched to identify randomised controlled trials that compared the effects of rotary and reciprocating instrumentation motions on postoperative pain. Two authors independently screened the search results, extracted the data, and assessed the quality using the Cochrane risk of bias tool. Due to numerous variables across studies, the random effect inverse variance method for meta-analysis was applied. When significant heterogeneity among studies was present, the random effects multi-variable meta-regression analysis was performed to determine the source of heterogeneity. Results At all time intervals, the incidence of postoperative pain was higher in the reciprocating instrumentation group, but was not statistically significant. There was no significant difference in the analgesic intake between groups. Meta-regression analysis determined study population sizes as a significant heterogeneous factor, while significance was not observed for preoperative pain or the pulpal diagnosis. Conclusion There was no difference in postoperative pain at 12, 24, and 48 hours after non-surgical root canal treatment and retreatment, using reciprocating or rotary instrumentation motions.

To compare the anesthetic efficacy of supplemental buccal infiltration (BI) (1.7 ml) versus intraligamentary (IL) injection containing 0.4 ml of 4% articaine with 1:100.000 epinephrine after an inferior alveolar nerve block (IANB) with 1.7 ml 2% lidocaine in the first and second mandibular molars diagnosed with irreversible pulpitis (IP).One hundred subjects diagnosed with IP of either the mandibular first (n = 50) or second molars (n = 50) and failed profound anesthesia following an IANB were selected. They randomly received either the IL or BI techniques of anesthesia. Pain scores on a 170 mm Heft-Parker visual analog scale were recorded initially, before, and during supplemental injections. Furthermore, pulse rate was measured before and after each supplemental injection. During the access cavity preparation and initial filing, no or mild pain was assumed to indicate anesthetic success. The chi-square test, Mann-Whitney U test, and independent samples t-test were used for the analyses.The overall success rates were 80% in the IL group and 74% in the BI group, with no significant difference (P = 0.63). In the first molars, there was no significant difference between the two techniques (P = 0.088). In the second molars, IL injection resulted in a significantly higher success rate (P = 0.017) than BI. IL injection was statistically more successful (P = 0.034) in the second molars (92%) than in the first molars (68%). However, BI was significantly more successful (P = 0.047) in the first molars (88%) than in the second molars (64%). The mean pulse rate increase was significantly higher in the IL group than in the BI group (P0.001).Both the IL and BI techniques were advantageous when used as supplemental injections. However, more favorable outcomes were observed when the second molars received IL injection and the first molars received BI.

There is lack of data on whether the coronavirus disease 2019 (COVID-19) pandemic was associated with changes in the etiology of pathosis in endodontic patients. The aim of this study was to determine the rate of cracks and other etiologic factors during the period of March 16th to May 31st in 2020 (COVID-19 initial outbreak) and 2021 (COVID-19 ongoing pandemic) compared with figures from the same period in 2019 (pre-COVID era) in 2 endodontists' practices.The etiologies of patients' chief complaints were determined from records of 2440 teeth (740 in 2019, 651 in 2020, and 1049 in 2021). Changes in the proportion of etiologic factors among all 3 periods were analyzed. The association between the rate of cracked teeth and patients' age and sex was determined using a logistic regression model.The rates of all etiologies collectively during the studied periods showed a significant change (P .0001). The rate of cracks significantly increased in 2020 (11.8%) (P = .0001) and 2021 (8%) (P = .0018) compared with 2019 (4.3%). The rate of persistent infections decreased in 2020 (22.3%) (P = .0013) and then increased in 2021 (27.5%) (P = .0153) compared with 2019 (30%). Cracked teeth were associated with the age group of 40-60 years (odds ratio [OR] = 1.882; 95% confidence interval [CI], 1.063-3.330) in 2020 and with age ranges of 40-60 years (OR = 2.051; 95% CI, 1.120-3.759) and60 years (OR = 2.038; 95% CI, 1.050-3.956) and male sex (OR = 1.599; 95% CI, 1.019-2.510) in 2021.The rate of cracked teeth increased during the initial outbreak of the COVID-19 pandemic and 1 year later. This study provided evidence on the association between the COVID-19 pandemic and changes in the rate and presentation of endodontic etiologic factors.

Conflicting findings on the potency of antibiotic pastes versus calcium hydroxide (CH) have been evident in the literature.To compare the antibacterial efficacy of single antibiotic paste (SAP), double antibiotic paste (DAP), triple antibiotic paste (TAP), and modified TAP (mTAP) with CH on bacterial biofilms.PubMed, Scopus, and Embase were comprehensively searched until August 23, 2021. The study protocol was registered in the PROSPERO.The qualitative and quantitative synthesis included 40 and 23 papers, respectively, out of 1421 search results. TAP (SMD = -3.82; CI, -5.44 to -2.21

The aims of this observational study were to determine if endodontists' practices in early 2021 experienced changes in patient characteristics compared with a comparable prepandemic period and to determine whether the changes reported during the initial outbreak of coronavirus disease 2019 (COVID-19) in 2020 were reversed 1 year later.Demographic, diagnostic, and procedural data of 2657 patient visits from 2 endodontist private offices from March 16 to May 31 in 2019, 2020, and 2021 were included. Bivariate analyses and multiple logistic regression models were used to examine the impact of ongoing COVID-19 pandemic on patient data.Bivariate analyses showed that patients' self-reported pain levels and the number of visits with irreversible pulpitis in 2021 were higher than 2019 (P.05). Patients' self-reported pain, percussion pain, and palpation pain levels in 2021 were less than 2020 (P .05). Multiple logistic regression analyses showed that endodontists' practices in 2021 had an increase in the number of nonsurgical root canal treatments (odds ratio [OR] = 1.482; 95% confidence interval [CI], 1.102-1.992), and apicoectomies (OR = 2.662; 95% CI, 1.416-5.004) compared with 2019. Compared with the initial outbreak in 2020, endodontists' practices in 2021 had visits with older patients (OR = 1.288; 95% CI, 1.045-1.588), less females (OR = 0.781; 95% CI, 0.635-.960), more molars (OR = 1.389; 95% CI, 1.065-1.811), and less pain on percussion (OR = 0.438; 95% CI, 0.339-0.566).The ongoing COVID-19 pandemic was associated with an increase in the number of nonsurgical root canal treatments. Some of the changes observed during the initial outbreak in 2020, including objective pain parameters, returned to normal levels 1 year later.

This systematic review (PROSPERO-CRD42020147333) aimed to compare the effects of conservative, ultraconservative and truss access cavities with traditional access cavities on the load capacity of root-canal-treated teeth. Online databases were searched until December 2021, and 25 ex vivo studies in which the effects of different access cavities on load capacity of permanent teeth had been investigated were included. Quality assessment was completed using a modified risk of bias tool for in vitro studies adapted from previous studies. Meta-analysis was performed using the maximum-likelihood-based random-effects model with similar groups. Conservative access cavities significantly improved the load capacity of maxillary premolars (p 0.01 [-1.32, -0.028]) and molars (p 0.05 [-0.89, -0.02]) compared to traditional access cavities. Additionally, truss access cavities significantly improved the load capacity of mandibular molars with (p 0.05, [-1.18, -0.02]) mesio-occluso-distal cavity preparations. Higher levels of evidence are needed to determine the long-term implications of minimal preparations for treatment outcomes.

Calcium hydroxide Ca(OH)2 has been used as an intracanal medicament to targets microbial biofilms and avert secondary infection in the root canal system. This study evaluated the effects of this material on the morphology and physicochemical properties of an established in-vitro biofilm of Enterococcus faecalis. A biofilm of E. faecalis was grown in multichannel plates. The chemicals including Ca2+, OH−, and saturated Ca(OH)2 (ie 21.6 mM) were prepared in order to evaluate which component eradicated or amplified biofilm structure. Various biochemical and microscopic methods were used to investigate the properties of the biofilm. Biofilms treated with Ca(OH)2 absorbed more Ca2+ because of the alkaline pH of the environment and the ions affected the physicochemical properties of the E. faecalis biofilm. A denser biofilm with more cavities and a granular surface was observed in the presence of Ca2+ ions. This resulted in a decrease in the surface-to-biofilm ratio with increases in its biomass, thickness, colony size, and volume. Calcium hydroxide did not destroy E. faecalis biofilms but rather contributed to the biofilm structure. This in-vitro study sheds light on a missing link in the formation of E. faecalis biofilm in which the Ca2+ in Ca(OH)2

The aim of the study is to investigate whether the 3-dimensional dynamic navigation system (3D-DNS) can improve experienced endodontists' (EEs') and novice endodontists' (NEs') accuracy and efficiency in osteotomy and root-end resection (RER) and to verify that the 3D-DNS enables NEs to perform osteotomy and RER as accurately and efficiently as EEs.Seventy-six roots in cadaver heads were randomly divided into 4 groups: 3D-DNS-NE, 3D-DNS-EE, freehanded (FH)-NE, and FH-EE (all, n = 19). Cone-beam computed tomography scans were taken preoperatively and postoperatively. Osteotomy and RER were planned virtually in the X-guided software (X-Nav Technologies, Lansdale). Accuracy was calculated by measuring the 2-dimensional and 3D virtual deviations and angular deflection using superimposing software (X-Nav technologies). Efficiency was determined by the time of operation and the number of mishaps.Accuracy deviations were significantly fewer in the 3D-DNS-EE group than those in the FH-EE group (P .05). We found less 2-dimensional and 3D accuracy deviations comparing the 3D-DNS-NE group to the FH-NE group (P .05). The time required for osteotomy and RER with the 3D-DNS was ∼ ½ of that required for the FH method for both EEs and NEs (P .05). We found no difference in the number of mishaps between the 3D-DNS and FH groups for EEs and NEs (P .05).The 3D-DNS improved EEs' and NEs' accuracy and efficiency in osteotomy and RER. The NEs were as efficient as the EEs using the 3D-DNS. Notably, the 3D-DNS improved the NEs' accuracy compared to the FH method, but the 3D-DNS did not enable the NEs to perform osteotomy and RER as accurately as the EEs.

Introduction The first outbreak of coronavirus disease 2019 (COVID-19) in the United States resulted in nationwide closure of dental offices that created an oral health crisis. The aim of this observational study was to analyze and compare the characteristics of patients who visited two private Endodontics offices from March-16 to May-31, 2020, compared to the same period in 2019. Methods Demographic, diagnostic, and procedural data of 1520 (693 in 2020; 827 in 2019) patient visits were collected. Bivariate and multiple logistic regression analyses were used to assess the impact of COVID-19 outbreak on patient-related variables. Results Bivariate analyses showed that the number of patient visits decreased in April and May 2020 (P 49.5 years) (odds ratio [OR], 0.720; 95% confidence interval [CI], 0.573-0.906), more patients with kidney diseases (OR, 2.690; 95% CI, 1.143-6.331), higher levels of pain on percussion (OR, 2.277; 95% CI, 1.718-3.016), less cases with previously initiated treatment (OR, 0.242; 95% CI, 0.080-0.731), less periapical diagnosis of asymptomatic apical periodontitis (OR, 0.510; 95% CI, 0.306-0.849), higher number of non-surgical root canal treatments (OR, 2.073; 95% CI, 1.397-3.074) and apicoectomies (OR, 2.799; 95% CI, 1.367-5.729). Conclusion These findings show that the public health burden of endodontic infections was more intense during the initial outbreak of COVID-19.

The aim of this study was to evaluate the effect of platelet-rich fibrin (PRF) placed in delayed replantation of mature extracted teeth. Sixteen intentionally extracted teeth in two mature beagle dogs were selected. In one quadrant of each jaw, the extraction sockets were filled with PRF prior to replantation, and the other quadrant served as control without PRF. All extracted teeth underwent endodontic treatment and dried for 60 min. Thereafter, they were replanted with a flexible splint. After 8 weeks, the animals were euthanised, and the histological sections examined. Less inflammatory root resorption was noted in the PRF group compared to the control (P = 0.031). However, there was no significant difference between the two groups with regard to new bone formation, inflammatory status, connective tissue healing and replacement resorption (P > 0.05). Using PRF in the extracted socket before delayed replantation did not provide any significant benefit other than reduced inflammatory root resorption.

Tissue engineering has evolved substantially in medicine and dentistry. It applies the concepts of both engineering and medicine to restore, maintain, or replace damaged biological tissues and organs. The potential of regenerative procedures in endodontics has been investigated by multiple studies, which have demonstrated the regeneration of pulp, dentin, and enamel using stem cells and scaffold materials. The field of regenerative endodontics is advancing rapidly. Management of immature teeth with pulp necrosis and apical periodontitis has been a challenge due to their thin root walls and open apices. With a better understanding of tissue engineering concepts and their application, regenerative endodontic treatment has emerged, and this has resulted in a paradigm shift in the treatment of these cases. The aim of this chapter is to review the goals and concepts of regenerative endodontics, the current challenges that clinicians may encounter, clinical aspects of the treatment based on the highest level of evidence, the AAE recommendations and guidelines, outcome assessment, limitations, and future directions.

Objective: To evaluate the efficacy of periapical infiltration injection of dexamethasone and morphine in reducing postoperative endodontic pain. Method: Ninety patients participated in this double-blind randomised controlled clinical trial. They were referred to the dental school of Shahid Beheshti Medical University, Tehran, Iran for conventional endodontic treatment of molar teeth. The canals of each tooth were completely prepared with cleansing and shaping. The patients were randomly divided into three experimental groups to receive dexamethasone, morphine or normal saline (1 mL). Patients were then instructed to complete a pain diary 4, 8, 24 and 48 h after the appointment. Statistical analysis consisted of chi-squared test, analysis of variance and Kruskal–Wallis test. Results: There was a statistically significant correlation between dexamethasone or morphine treatment and decreased levels and incidence of endodontic pain at 4, 8 and 24 h, but not at 48 h (P

Examining the evolution of research parameters helps scientists to discover the well-developed and neglected aspects of knowledge. Pain after root canal treatment is a health problem affecting millions of patients. Research in this field has a meaningful impact on quality of lives. The aim of this study was to analyze the evolution of research on postoperative pain over the past 50 years.Electronic searches were performed in Scopus and MEDLINE databases to identify studies on pain after nonsurgical root canal treatments/retreatments. The full texts of eligible articles were reviewed to determine the study category and to extract and analyze the methodological variables. A series of statistical analyses were performed to determine the trend of publications based on the variable of interest over time.Four hundred twenty-four articles were included. There was a positive trend for systematic reviews, studies with sample size200, studies on single-visit treatment, and clinical trials on instrumentation and adjunct treatments (P.05). There was a negative trend for the use of numeric rating scales, studies on multiple-visit treatments, clinical trials on medication/medicament, and studies on pain in maxillary incisors (P.05). No trend was observed based on pulpal diagnosis or for studies with longer observation periods (8 weeks) (P.05).A paradigm shift is needed toward clinical studies with larger sample sizes, longer observation periods, and more focus on pulpal diagnoses associated with higher rates of postoperative pain. There is a need to view postoperative pain as an important patient-centered outcome and to develop and disseminate standard reporting guidelines for future studies.

The treatment of calcified root canals is challenging in endodontic practice. A 63-year-old man was referred to the postgraduate endodontic clinic at the University of Maryland School of Dentistry, Baltimore, MD, for the treatment of tooth #3. Because of the patient's history of head and neck radiation and the high risk of developing osteoradionecrosis, a nonsurgical endodontic approach was found to be the most reasonable treatment option despite the questionable prognosis of the tooth. During the endodontic treatment, the distobuccal canal appeared to be partially calcified and was not possible to be located freehand even with use of the dental operating microscope and cone-beam computed tomographic approximated approach. Therefore, the dynamic navigation system using the X-Guide system (X-Nav technologies, LLC, Lansdale, PA) was used, which allowed for the successful location of the canal. Conventional endodontic treatment was completed following standardized instrumentation, irrigation, and obturation. Details on how to use the dynamic navigation system are described including its advantages, disadvantages, and limitations.

Introduction Calcified canals present a challenge during endodontic treatments. The purpose of this study was to compare the accuracy and efficiency of a dynamic navigation system (DNS) to the freehand (FH) method for locating calcified canals in human teeth. Methods Sixty human single-rooted teeth with canal obliteration were selected and mounted in dry cadaver jaws. Based on cone-beam computed tomographic scans of the jaws, the drilling path and depth were virtually planned to use X-Guide software (X-Nav Technologies, LLC, Lansdale, PA). Access preparation was made with navigation in the DNS group and without guidance in the FH group by 2 operators with different levels of experience. Postoperative cone-beam computed tomographic scans were taken of all teeth. Linear and angular deviations and reduced dentin thickness at 2 levels were measured. The time for locating the canal, the number of mishaps, and the unsuccessful attempts were determined and analyzed. Results The mean linear and angular deviations, reduced dentin thickness (at both levels), the time for access cavity preparation, and the number of mishaps in the DNS group were significantly less than the FH group (P ≤ .05). The unsuccessful attempts were not different between the 2 groups (P > .05). The time for access preparation was significantly shorter for the board-certified endodontist in the FH group (P ≤ .05). Conclusions The DNS was more accurate and more efficient than the FH technique in locating calcified canals in human teeth. This novel DNS can help clinicians avoid catastrophic mishaps during access preparation in calcified teeth.

Previous in vitro studies have suggested that simvastatin can be used as a direct pulp capping material due to its ability to induce odontoblastic differentiation and angiogenesis. The aim of this animal study was to evaluate the pulpal response to mineral trioxide aggregate (MTA) and four concentrations of simvastatin/MTA in combination. The study was conducted in two stages using four different simvastatin concentrations and MTA as a capping material for rat maxillary molars. The grades of inflammation and continuity of dentin formation were evaluated in hematoxylin and eosin (HE)-stained samples. Dentin thickness was determined by histomorphometric analysis, and the data were subjected to statistical analysis. On day 3, mild inflammation was observed in all groups. On day 7, the simvastatin groups showed a slightly higher rate of chronic inflammation. Inflammation was not present on day 30. Discontinuous dentin was present in all methylcellulose (control) samples. Continuous dentin was formed in all of the samples treated with 1.5% simvastatin. The greatest dentin thickness was observed after treatment with 1.5% simvastatin and MTA, followed by 0.5% simvastatin. Statistical analysis demonstrated no significant differences in dentin thickness and continuity between MTA and simvastatin at 0.5% and 1.5% (P > 0.05).

Aim: The aim of the current study was to compare the effect of WaveOne and Reciproc files in reciprocation versus reverse full rotation movements on cervical dentin thickness by virtue of cone beam computed tomography (CBCT) analysis in curved mesial canals of mandibular first molars. Methods: Mesiobuccal canals of 60 mandibular molars were randomly divided into 4 groups (n = 15): Group 1; WaveOne/Reciprocation, Group 2; WaveOne/Full-Rotation, Group 3; Reciproc/Reciprocation, and Group 4; Reciproc/Full-Rotation. Pre- and post-instrumented CBCT scans were prepared for assessment of cervical dentin thickness changes (2 mm, 4 mm below the highest point of the root furcation) in both groups. Data statistically analyzed using two-way ANOVA test. Results: There was no statistically significant difference between four experimental groups in terms of remaining dentin thickness at 2 and 4 mm levels below the highest point of the furcation (P > 0.05). No separation of instruments occurred in any group. Conclusion: WaveOne and Reciproc files with two different motions have similar effects on cervical of root canals in terms of dentin thickness changes.

Objectives This study aimed to assess the effect of DentalVibe on the level of pain experienced during anesthetic injections using 2 different techniques. Materials and methods This randomized crossover clinical trial evaluated 60 patients who required 2-session endodontic treatment. Labial infiltration (LI) anesthesia was administered in the anterior maxilla of 30 patients, while inferior alveolar nerve block (IANB) was performed in the remaining 30 patients. 1.8 mL of 2% lidocaine was injected at a rate of 1 mL/min using a 27-gauge needle. DentalVibe was randomly assigned to either the first or second injection session. A visual analog scale was used to determine participants' pain level during needle insertion and the anesthetic injection. The paired t-test was applied to assess the efficacy of DentalVibe for pain reduction. Results In LI anesthesia, the pain level was 12.0 ± 15.5 and 38.1 ± 21.0 during needle insertion and 19.1 ± 16.1 and 48.9 ± 24.6 during the anesthetic injection using DentalVibe and the conventional method, respectively. In IANB, the pain level was 14.1 ± 15.9 and 35.1 ± 20.8 during needle insertion and 17.3 ± 14.2 and 39.5 ± 20.8 during the anesthetic injection using DentalVibe and the conventional method, respectively. DentalVibe significantly decreased the level of pain experienced during needle insertion and the anesthetic injection in anterior LI and mandibular IANB anesthesia. Conclusions The results suggest that DentalVibe can be used to reduce the level of pain experienced by adult patients during needle insertion and anesthetic injection.

Root canal perforation due to root resorption is a challenging clinical circumstance to properly diagnose and treat, particularly when it occurs in anterior teeth. Extraction of the involved tooth and subsequent replacement with an osseointegrated implant is usually indicated in many cases. This study presents a case management of a maxillary central incisor with perforating internal root resorption in the coronal third of the root. The treatment plan consisted of endodontic treatment with Mineral Trioxide Aggregate, surgical operation, internal bleaching and coronal restoration.

The aim of this randomized clinical trial was to compare the success rate of three different anesthetic techniques in mandibular molars with symptomatic irreversible pulpitis. Ninety patients with symptomatic irreversible pulpitis in mandibular molars randomly received three anesthetic techniques. Group I: an inferior alveolar nerve block (IANB) of 2% lidocaine. Group II: IANB and buccal infiltration (BI) of 4% articaine. Group III: IANB + BI and intraseptal injection of articaine in each mesial and distal papilla. The pain (Heft-Parker visual analog scale (VAS)) and electric pulp tester (EPT) scores were recorded prior to (VAS1, EPT1) and after the injection and during access preparation (VAS2, EPT2). The success of anesthesia was defined as the ability to access the tooth with no or mild pain (VAS ≤ 54). The mean value for VAS2 was significantly less and the mean value for EPT2 was significantly more in groups II and III compared with group I. The success rates for groups I, II, and III were 30.33%, 66.66%, and 80.00% respectively. Also, differences of EPT2, VAS2, and success rates were statistically significant between groups II and III. Administration of articaine as a supplemental intraseptal and BI following IANB can be considered a more successful anesthetic technique in mandibular molars with symptomatic irreversible pulpitis compared with the conventional IANB and supplemental BI. The addition of an articaine intraseptal injection to IANB+BI technique may result in a significantly higher success rate of pulpal anesthesia in mandibular molars with symptomatic irreversible pulpitis.

The aim of this study was to assess the frequency of root crack formation caused by the use of manual instrumentation, 2 rotary systems, and 1 reciprocating system using light-emitting diode transillumination.One hundred fifty mandibular premolars were randomly divided into 5 groups (n = 30): control 1, no intervention; control 2, instrumented with hand files; group 3, instrumented with ProTaper Universal rotary files (Dentsply Maillefer, Ballaigues, Switzerland); group 4, instrumented with OneShape rotary files (Micro-Mega, Besancon, France); and group 5: instrumented with the WaveOne reciprocal system (Dentsply Maillefer, Ballaigues, Switzerland). After root canal preparations, the roots were sectioned at 3, 6, and 9 mm from the apex with water irrigation. The slices were inspected under a stereomicroscope with light-emitting diode transillumination from the buccal, lingual, mesial, and distal directions at ×40 magnification to determine the presence/absence of cracks (dentinal defects). The chi-square test was used to analyze the data.There was a significant difference among the groups in crack frequency (P.05). The 2 single systems had significantly higher cracks than the other 3 groups. At 3 mm from the apex, there were significantly more cracks in groups 4 and 5 than in groups 1, 2, and 3 (P.05). At 6 mm from the apex, no significant difference was noted (P.05). At 9 mm from the apex, the frequency of cracks in group 3 was significantly higher (P.05).According to the results, using rotary instrumentation can result in some dentinal defects, and single-file systems, regardless of motion type, can cause significantly higher crack formation in the apical third of root canals.

This study compared the antibacterial effect of 2% clindamycin and 2% and 100% concentration of triple antibiotic paste (TAP) on an Enterococcus faecalis biofilm. Dentinal tubules of 100 root specimens were infected and randomly assigned to five groups. A total of 1000 mg mL-1 of TAP, 20 mg mL-1 of TAP and clindamycin, calcium hydroxide or methylcellulose (control) were placed in the root canal for 1 week. After treatment, dentine shavings were collected from 200 and 400 μm dentine depth and the number of colony-forming units (CFU) per mg was determined. Reduction in viable bacteria in first three groups was significantly better than calcium hydroxide and control groups. However, the antimicrobial effectiveness among these three groups was not significantly different from each other. There was no significant difference between data at 200 and 400 μm in all groups except the Ca(OH)2 group. The antibiofilm effect of clindamycin was comparable with TAP, so it may be used instead of TAP.

Introduction The susceptibility of endodontically treated teeth (ETT) to fracture is mainly associated with the loss of tooth structure. This study evaluated the effect of the access cavity design and taper preparation of root canals on ETT fracture resistance of maxillary molars. Methods For tapering assessment, 30 sound distobuccal roots of maxillary molars were randomly assigned to 1 of 3 groups (n = 10): a .04 taper, a .06 taper, or a .08 taper. Endodontic canal preparations were performed using the Twisted Files rotary system (Kerr Co, Glendora, CA). In addition, 48 intact maxillary first and second molars were randomly assigned to 1 of 3 groups (n = 16) for cavity preparation approaches: intact teeth, traditional access cavity (TAC), or conservative access cavity (CAC). Fracture resistance was tested using a universal testing machine. For statistical analysis, the level of significance was P ≤ .05. Results The .04 taper instrumentation had the highest fracture resistance (259.61 ± 52.06), and the .08 taper had the lowest (168.43 ± 59.63). The .04 and .06 groups did not differ significantly (P > .05); however, these groups differed significantly from the .08 group (P ≤ .05). Regarding the cavity preparation approaches, the 3 groups of intact teeth, CAC, and TAC showed fracture resistance mean values of 2118.85 ± 336.97, 1705.69 ± 591.51, and 1471.11 ± 435.34, respectively, with no significant difference between the CAC and TAC groups (P > .05). Conclusions Increasing the taper of the root canal preparation can reduce fracture resistance. Moreover, access cavity preparation can reduce resistance; however, CAC in comparison with TAC had no significant impact.

Introduction: Gutta-percha (GP), is a neutral and non-toxic material. The aim of this animal study was to compare the biocompatibility of nanosilver coated GP (NS-GP) with conventional GP in subcutaneous tissues in a rat model. Methods and Materials: Conventional GP and NS-GP were subcutaneously implanted in the backs of 20 male Wistar rats (n=10). A control animal was assigned for each trial period. Ten animals were sacrificed after 7 and 30 days and light microscopic evaluation of tissue reaction to NS-GP (n=20) and conventional GP (n=20) was accomplished. The Mann-Whitney U, Wilcoxon Signed Ranks, Fisher Exact, and McNemar tests were used for statistical analysis of the data. Results: After 7 days, inflammation was moderate and mild for NS-GP and conventional GP, respectively (P