The aim of this study was to evaluate the main calcium silicate-based root canal sealers (bioceramic-based root canal sealers) currently used in endodontic field as well as their specific characteristics and to compare with other conventional sealers. A review of the literature was made to evaluate numerous investigations covering different properties of these materials. The properties of interest were physical properties, bond strength, pH, radiopacity, solubility, setting and working time, dimensional changes, flow, calcium ion release, biocompatibility, antimicrobial activity, sealing ability, adhesion, and cytotoxicity. The outcome of these studies of bioceramic-based sealers revealed favorable biological and physicochemical properties along with comparative investigations of other agents. It was concluded that bioceramic-based sealers, in spite of drawbacks of some, were found to be attractive due to their bioactivity, dimensional stability, and acceptable physicochemical properties in comparison with other conventional sealers.

Restoration of pulpless teeth presents a clinical challenge and a controversial topic of debate even today. The preservation of coronal tooth structure is crucial for clinical success and for maintaining biomechanical, adhesive, functional, and esthetic balance. The advent of adhesive dentistry and advancement in dental materials have resulted in mechanical properties close to the dental tissues, thereby offering a conservative treatment option to restore, reinforce, and protect endodontically treated teeth (ETT). Directly bonded restorations are indicated for teeth with the minimal loss of coronal tooth structure and can be considered effective for short-term success of root canal treated teeth. However, indirect restorations could be considered for the strengthening of the tooth with moderate loss of tooth structure, following the adequate adhesive protocols. The present review assesses literature on direct versus indirect adhesive restorations such as endocrowns, adhesive onlays, and overlays for restoring ETT. Furthermore, the article attempts to present clinical guidelines and decision-making for restoring endodontically treated anterior and posterior teeth.

Introduction: An apico-marginal defect is a combined endodontic periodontal lesion that poses a challenge to the healing outcome and therefore often leads to the decreased prognosis of periapical surgery. This systematic review aims to analyze clinical studies and case reports that show evidence of the effect of autologous platelet aggregates on the healing outcome of apico-marginal defects. Materials and Methods: Literature search strategy was performed to find relevant clinical studies and case reports according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist. The question was “healing outcome of apico-marginal defects treated using autologous platelet aggregates.” The review involved a search of electronic databases of Pubmed, Scopus, Ebsco host, as well as manual search. Results: Five relevant literature published between 1990 and June 2019 were selected after thorough analysis and exclusion according to the strict criteria. The included studies were related to clinical and radiographic healing outcome of apico-marginal defects with autologous platelet aggregates. Conclusion: The collected data suggested that autologous platelet aggregates give a favorable healing outcome for the management of apico-marginal defects.

Introduction: The aim of this study is to evaluate radiographically the quality of root filling in endodontically treated teeth among a Riyadh population in governmental and private hospitals. Materials and Methods: Four hundred radiographs or obturated root canals in government and private hospitals were evaluated with regard to length, taper, and density of the root canal filling. The criterion-based number of adequate fill was identified and the root canal obturations were categorized as adequate or inadequate. Results: There were a statistically significant higher percentage of adequately obturated root canals in terms of length, density, and taper in government hospitals as compared to private hospitals. Moreover, the proportion of adequate length and taper of root canal was significantly higher in anterior teeth when compared with premolar and molar teeth in both private and governmental hospitals. There was no statistically significant association between the assessment of density of root canal and the type of tooth. Conclusion: The overall quality of the root canal filling in endodontically treated teeth in governmental hospitals was higher than in private hospitals and higher than some reported studies around the world.

Introduction: This study aimed to assess the radiographic and histopathologic outcomes of immature dog teeth with apical periodontitis after revascularization using propolis. Materials and Methods: Periapical pathosis was induced in 48 double-rooted premolars in six dogs aged 6–9 months. The root canals were irrigated with 10 mL of 2.25% NaOCl per tooth. The teeth were divided into two groups (24 teeth each) according to the disinfection of root canals as follows: Group I (propolis group): disinfected with propolis paste and Group II (control group): without disinfectant. After 3 weeks, bleeding was induced to fill the canal spaces, the pulp chamber of the teeth was plugged with mineral trioxide aggregate, and the access cavities were sealed with glass ionomer cement. Samples were classified into three subgroups depending on the evaluation period as follows: subgroup i: 2 weeks, subgroup ii: 4 weeks, and subgroup iii: 8 weeks. Increase in the root length and root thickness and decease of apical diameter were assessed by radiography, and new hard tissue, vital tissue, and apical closure scores were assessed by histology. All data were statistically analyzed. Results: There were statistically significant differences between both groups regarding the increase in root length, increase in root thickness, decrease in apical diameter, new hard tissue, and vital tissue in all subgroups (P ≤ 0.05). There was a statistically significant difference between both groups regarding the apical closure at 8 weeks only (P < 0.05). Propolis group showed formation of cementum-like tissue along the inner aspect of root dentin and newly formed dentin layer along the inner aspect of the root with pulp-like tissue and odontoblasts. Conclusion: Propolis is capable of inducing hard-tissue deposition and soft-tissue formation inside the necrotic pulp after revascularization of immature permanent teeth.

Introduction: The present study was undertaken to determine the accuracy of working length using cone-beam computed tomography and Ingle's method and to compare it with actual working length using visual method. Materials and Methods: A total number of 52 single-rooted human teeth mounted on blocks of dental stone were subjected to cone-beam computed tomography (CBCT) by tracing a line between the apical foramen and the corresponding cusp tip from the scans taken before instrumentation. The measurement was taken in two planes in preoperative periapical radiographs. Working length was calculated using Ingle's method from periapical radiographs. The actual working length was measured using visual method under magnification (×2.5). All the measurement procedures were performed by an endodontist and a radiologist. Data were analyzed using SPSS software version 15. Results: One sample t-test was applied to compare between the actual working length determined by the visual method and the working length determined by CBCT, and Ingle's method showed that there was no statistically significant difference (P > 0.05) between the groups. Inter-examiner reliability test using Cronbach's alpha showed a good agreement between the radiologist and the endodontist for both periapical radiography and CBCT. Conclusion: The preoperative CBCT is better than Ingle's method in determining working length within a narrow range of ±0.5 mm. If preoperative CBCT scans are available, the dentist should make the use of the scan for determining the working length instead of exposing them for repetitive radiographs.

Introduction: Decreased lecture attendance in undergraduate dental education has been observed worldwide. The limited studies on the influence of lecture attendance on dental students' performance have yielded inconclusive results. Hence, the aim of this study was to evaluate the influence of lecture attendance on dental students' academic performance and determine if the past performance of students in prerequisite courses is predictive of their performance in an endodontic course at College of Dentistry, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia. Materials and Methods: This was a correlational study design in which historical data for students (n = 158) enrolled in Endodontics II (ENDD 512) course were obtained for two consecutive academic years. Data were collected from grade transcripts provided by the assessment unit, and lecture attendance records were taken by the student affairs unit. The data were analyzed statistically. The level of significance (α) was set as 0.05. Results: The percentage of lectures attended had a weak correlation with ENDD 512 final grades (r = 0.108, P = 0.179). Comparison to previous academic performance showed that endodontic course grades were strongly correlated with all prerequisite course grades (P < 0.01). Conclusion: The students' performance in the course was most strongly predicted by their performance in certain prerequisite courses, while attendance was not a significant predictor.

Introduction: The aim of this study was to investigate the role of the cross-sectional design surface in improving the cyclic fatigue resistance by comparing two nickel–titanium (NiTi) rotary instruments with the same heat-treatment and grinding procedure. Materials and Methods: A total of 40 new NiTi instruments (20 S-One 25.06 taper and 20 AF Blue S4 25.06 taper) were tested in the present study. Both instruments were rotated at 300 rpm and with a torque setting of 2 Ncm) using an endodontic motor in the same artificial canal (90° angle of curvature and 3 mm radius). A Student's t-test was performed to determinate the differences in terms of time to fracture (TtF) and the length of the fractured portion between the two different instruments. Significance was set at P < 0.05. Results: The differences in terms of TtF for cyclic fatigue resistance between the two files were statistically significant (P < 0.05). In terms of fractured length, not statistically significant differences were found (P > 0.05). Scanning electron microscopy images showed patterns of cyclic fatigue striations. Conclusion: The results of this study confirm and enhance the role of cross-section in increasing the cyclic fatigue resistance of NiTi rotary instruments.

Introduction: The aim of this study was to evaluate the pulpal response after pulp capping using either biodentine (BD) or tech biosealer capping (TBC) in the dog model. Materials and Methods: Class V cavities were carried out on 45 teeth in three mongrel dogs. The dental pulp was exposed in 30 teeth (2 experimental groups) and left unexposed in 15 teeth (control group). The cavities of the experimental groups were capped with either BD (n = 15 teeth) or TBC (n = 15 teeth). All cavities in the experimental and control groups were restored with resin-modified glass ionomer. Dentin bridge formation, architecture of the odontoblastic layers, and signs of inflammation were assessed after 1, 2, and 3 months using the computer image analyzer. Results: The BD group exhibited a thick newly formed reparative dentin bridge completely closing the exposure site with cell inclusions and mineralization, variable numbers of odontoblast-like cells, preserved pulp tissue, marked numerous collagen fibers, and blood vessels. While the TBC group exhibited an incomplete newly formed reparative dentin bridge with tunnel defect, vacuolated odontoblasts, complete pulp degeneration with multiple edematous spaces, hyperemic blood vessels, extravasated red blood cells, multiple calcified structures scattered just beneath the dentin bridge and through the pulp tissue, and newly ill-defined odontoblasts. Conclusion: For pulp capping, BD has a better dentin bridge formation and pulp preservation than TBC in the dog model.

Introduction: The aim of this in vitro study was to evaluate the cytotoxic effects of chlorhexidine (CHX), ethylenediaminetetraacetic acid (EDTA), and sodium hypochlorite (NaOCl) irrigants on human gingival fibroblasts. Materials and Methods: Gingival fibroblasts were cultured in Dulbecco Modified Eagle Medium for 24 h. Then, the cells were exposed for 1 min to different concentrations of CHX, EDTA, and NaOCl and the cell viability was assessed using 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide tetrazolium reduction assay. The percentage of gingival fibroblast viability was compared to control (100% viability). Results: All concentrations of CHX, EDTA, and NaOCl were cytotoxic to gingival fibroblasts compared to control group and this effect was dose-dependent (P < 0.0001). There was an inverse relationship between the concentrations of these irrigants and cell viability. The highest clinically used concentrations of CHX (2%), EDTA (17%) and NaOCl (2.5%) reduced the cell viability to 2.2%, 3.2%, and 1.9%, respectively, compared to the 100% viability of control. However, the lowest concentration of CHX (0.00002%), EDTA (0.00017%), and NaOCl (0.000025%) increased the cell viability to 39.8%, 30.2%, and 44.2%, respectively, in comparison to control. There were no significant differences between the irrigants at clinically used concentrations (P > 0.05). Conclusion: The cytotoxic effect of CHX, EDTA, and NaOCl on gingival fibroblasts was dose-dependent. Further studies are needed to assess and optimize the safety and efficacy of these irrigants in vivo.

Introduction: The objective of this study was to assess the efficacy of a simple irrigation kit, employing the apical negative pressure principle, assembled from easily obtainable materials in the dental hospital setting, on smear layer removal from the apical third of the root canal surface. Materials and Methods: The root canals of forty single-rooted mandibular premolars were mechanically prepared, and the teeth were then randomly divided into three groups to be irrigated with conventional needle irrigation (CNI) system, passive ultrasonic irrigation (PUI) system, and the simple apical negative pressure (ANP) kit. Four specimens were used as a negative control. After irrigation, the teeth were split longitudinally and examined under scanning electron microscopy at 1 mm, 3 mm, and 5 mm from the working length. The remaining smear layer was analyzed to assess the efficacy of each irrigation system. Results: The least remaining smear layer was observed in the ANP group at all three distances from the working length (P < 0.001). Furthermore, significantly less remaining smear layer was observed in the PUI group 3 mm and 5 mm from the working length than the CNI group (P < 0.01), whereas there was no significant difference between the use of PUI and CNI 1 mm from the working length. Conclusions: In this in vitro study, the assembled simple ANP kit had greater efficacy at delivering irrigants to remove the smear layer from the apical third of the root canal surface than the CNI and PUI systems.

Introduction: The aim of this study was to evaluate the effect of ultrasonic and sonic activation using three irrigants on mature Enterococcus faecalis biofilm. Materials and Methods: Seventy single-rooted premolars were prepared and sterilized. Mature E. faecalis biofilm was developed. Roots were randomly divided into three groups (n = 21) according to activation technique: ultrasonic, sonic, and positive control. Each group was further subdivided into three subgroups (n = 7) according to the irrigant used: 4% propolis, 2% chlorhexidine (CHX), and 2.5% sodium hypochlorite. Samples were cut and scanned using confocal laser scanning microscopy. The fluorescent images were analyzed using Zen imaging software. Data analysis was performed using one way analysis of variance and Tukey's honestly significant difference test for pairwise comparison. Statistical significance was set at 5%. Results: Both activated groups showed a statistically significant bacterial reduction (P ≤ 0.001). CHX showed the highest antibacterial effect. Conclusions: Irrigant activation is an essential step in reduction of bacterial counts. CHX has a potent antibacterial effect against mature E. faecalis biofilm.

Introduction: The present in vivo study was carried out to compare the clinical and radiographic success rates of mineral trioxide aggregate (MTA) pulpotomy and laser-assisted MTA pulpotomy in human primary molars. Materials and Methods: The present study was a randomized clinical trial in design, wherein forty human primary teeth requiring pulpotomy treatment which met the selection criteria (clinical and radiographic) were divided into two groups, Group 1 (n = 20) wherein the pulpotomy was performed with MTA alone and Group 2 (n = 20) wherein laser-assisted pulpotomy was performed with diode laser-assisted MTA (L-MTA). The patients were recalled after 3, 6 and 9 months, respectively, and evaluated clinically and radiographically. Data were analyzed statistically, while P< 0.05 was considered statistically significant. Results: The clinical success rate in the MTA group was 90%, 84.21%, and 88.23% at 3, 6, and 9 months, respectively, with no clinical signs or symptoms reported at the said follow-up visits, while the radiographic success rate was found to be 85%, 84.21%, and 82.3%, respectively. On the contrary, the clinical success rate in the L-MTA group was found to be 95%, 94.74%, and 94.44% at 3, 6, and 9 months, respectively, with the radiographic success rate reported being 90%, 89.47%, and 88.89%, respectively. Conclusion: The combination of diode laser and MTA yielded better clinical and radiographic success rates over the pulpotomy procedures done with the help of MTA alone, thereby, concluding that lasers may be considered as adjuvant alternatives for vital pulp therapy on human primary teeth.

Introduction: The aim of the present study is to evaluate the torsional resistance and the operative torque of two different files and to introduce the concept of “torque range”, that indicates the difference between torque at failure and operative torque. Materials and Methods: 20 ProTaper Next^® (PTN) X1 and 20 EdgeFile^® X7 17.04 were randomly divided into two equal groups (n = 10) and were subjected to the following two tests: operative torque recorded during root canal shaping of a single-rooted mandibular premolar and a torsional test performed at 300 rpm while the apical 3 mm of each file were firmly secured. The torque range was calculated from the difference between “Operative torque” and “torque at fracture.” A statistical t-test was performed to determinate the difference. Statistical significance was set at P < 0.05. Results: EdgeFile X7 instruments reached the working length significantly faster and with less torque generated (P < 0.05) compared to PTN . In torsional static resistance (torque at failure), the two files demonstrated no significant different values (P > 0.05). The range between the mean values of maximum torque at failure and operative torque, “torque range,” was twice bigger for EdgeFile X7 instruments. Conclusions: The EdgeFile X7 has a wider “torque range” when compared to PTN X1. This new concept could be a relevant innovation to match in vivo and in vitro studies and to obtain a more clinically relevant result.

Introduction: This study aims to study the efficiency of manual dynamic agitation (MDA) combined with ethylenediaminetetraacetic acid (EDTA) containing 0.25% cetrimide in smear layer removal of mechanically prepared root canals after final irrigation. Materials and Methods: The root canals of 120 premolars were prepared using Mtwo^® rotary instruments. The roots were randomly divided into six groups (n = 20): negative control (G1), irrigated with normal saline, and positive control (G2), irrigated with 17% EDTA followed by 2.5% sodium hypochlorite (NaOCl). The reaming four groups were irrigated with 17% EDTA followed by 2.5% NaOCl with MDA and agitated with gutta-percha (G3), irrigated with 17% EDTA followed by 2.5% NaOCl (both with MDA) (G4), irrigated with 17% EDTA containing 0.25% cetrimide followed by 2.5% NaOCl (both with MDA) (G5), and irrigated with SmearClear™ EDTA followed by 2.5% NaOCl (both with MDA) (G6). Subsequently, the specimens were evaluated under scanning electron microscopy. The amount of smear layer in each specimen, 1 mm, 3 mm, and 5 mm of the apical third of the root canal, was scored using Gutmann's scoring system. Data were statistically analyzed using the Kruskal–Wallis and Mann–Whitney U tests. Results: The least smear layer score was observed in Group 5 (P < 0.05). Utilizing MDA with EDTA and NaOCl (Groups 4-6) led to significantly reduced smear layer score compared to negative and positive control. Even MDA for NaOCl alone (Group 3) had significantly cleaner walls compared to negative and positive control (P < 0.05). Conclusions: Supplementation with MDA in the final root canal irrigation step promoted a significantly cleaner surface of the mechanically prepared root canal wall at the apical level. Further, the use of EDTA containing 0.25% cetrimide significantly improved smear layer removal.

Mandibular canines, in most cases, have one root and one canal. Some investigators reported a morphological variation in mandibular canals. This report documented a case of mandibular canine of a healthy 53-year-old female patient referred for evaluation of deep caries located in the buccocervical region of the crown, which had reached the pulp chamber. Cone beam computed tomography revealed one root with two canals (Vertucci Type II). A diagnosis of symptomatic irreversible pulpitis and asymptomatic apical periodontitis was established, and nonsurgical root canal treatment was performed with the help of dental operating microscope. The use of good diagnostic tools improves the accuracy of the diagnosis and the success of the treatment.

The roots and canals of maxillary second premolar have different typical anatomical features, as well as a number of anatomical variations and extra canals. The present cases describe the successful endodontic therapy of two maxillary second premolars with three canals of healthy individuals, with the help of cone-beam computed tomography and dental operating microscope. The first case was diagnosed as symptomatic irreversible pulpitis with asymptomatic apical periodontitis, and the second case was diagnosed as necrotic pulp with normal periapical area. Follow-up visits reported no symptoms of both patients. The awareness toward atypical anatomy can be a critical factor in determining the success of endodontic treatment.

Endodontic-periodontal lesions can originate from infections of the periodontium or tissues of the dental pulp. Dental trauma to the face can affect teeth and cause pulp necrosis, which, in turn, leads to periodontal breakdown, pocket formation, and alveolar bone loss. These types of lesions are categorized as retrograde periodontal lesions of endodontic origin, which is the same condition of the case presented in this report. A 37-year-old healthy male had trauma 6 months ago and reported with a chief complaint of oral pain while biting on his maxillary right canine. Clinical examination revealed Grade II mobility and a deep periodontal pocket. Radiographic examinations showed an advanced bone resorption around the tooth. Pulp necrosis with symptomatic apical periodontitis was diagnosed. Root canal treatment was performed and the case was followed for one year. Thorough history taking and investigation led to successful outcome, with the tooth exhibiting complete soft - and hard-tissue healing.