Introduction: Intracanal medication with calcium hydroxide is an important adjunct to disinfection after the chemomechanical preparation. A dense and homogeneous filling up to the working length positively influences the outcome of endodontic treatment in infected cases. The optimum placement of intracanal medicament can many times become a challenging task, owing to the lack of usage of the appropriate instruments and techniques. Aim: The aim is to gather and assess available literature on the rationale of calcium hydroxide placement, instruments, and techniques for effective delivery. Materials and Methodology: An electronic search was conducted using the PubMed Database from 1970 to 2019 using the keywords “delivery of calcium hydroxide,” “placement of calcium hydroxide,” “density of calcium hydroxide.” The articles pertaining to the comparison between the placement techniques of calcium hydroxide dressing were analyzed. Results: The search identified 433 articles, from which 419 articles that did not fulfill the inclusion criteria were excluded from the study and eventually 13 research articles were analyzed for the review. Conclusion: The density of calcium hydroxide and the technique of placement may affect the healing outcome especially in cases of pulp necrosis with apical periodontitis. The use of lentulo spirals at lower speeds seems effective in intracanal delivery of calcium hydroxide.

Introduction: The objective of this article was to review the diagnostic tools and treatment modalities used in root canal treatment of taurodont teeth in published case reports and case series. Materials and Methods: An electronic search of the literature was performed in PubMed (Medline), EBSCOhost databases, and the reference lists of articles that had been published from 1990 to 2019. Data of the articles that had been included were extracted. Results: The initial search led to the retrieval of 558 articles. After removing duplicates, 121 articles were left, the titles of these articles along with abstracts were read which resulted in the selection of 48 articles for full-text reading. Thirty-six articles were later selected for data extraction and qualitative analysis. In all these articles, treatment was discussed for taurodontism. Conclusion: Treating a taurodont tooth can be quite a challenge and careful evaluation and treatment planning is important for a successful outcome.

Introduction: The objective was to explore the impact of root canal instrumentation on the surface nanoscale characteristics of M-wire (ProTaper Next^®[PTN]) and R-phase (twisted file [TF]) nickel–titanium (NiTi) instruments. Materials and Methods: Endodontic cleaning and shaping was performed on the curved canals of the mesial roots of mandibular extracted molars (n = 32). Canal curvatures ranged from 20° to 30° according to the Schneider method. PTN and TF NiTi instruments were used for this purpose. The surface parameters of NiTi instruments were evaluated before and after the root canal instrumentation using a Dektak three-dimensional nanoscale surface profiler. An analysis of variance and Student's t-test were used to determine the significance of various parameters of the NiTi instruments before and after the root canal instrumentation. The statistical significance level was set at P < 0.05. Results: There were no significant differences in the root mean square roughness (Sq), average roughness value (Sa), and peak to valley height (Sz) in flutes between the instruments (P > 0.05) or in the Sq in blade location. However, the Sa and Sz in blade location were significantly greater for TF than PTN. The TF instruments had greater surface roughness than PTN. The PTN instruments exhibited minor surface cracks, while TF instruments exhibited cracks and microcavities. Conclusion: Endodontic instrumentation altered the surface characteristics; the surface distortion was significantly greater for the TF instruments than the PTN instruments.

Introduction: This study aims to compare and evaluate the effects of Irritrol and 17% ethylenediaminetetraacetic acid (EDTA) on the root dentin microhardness. Materials and Methods: A diamond disc was used to decoronate 15 human noncarious maxillary central incisors at the cemento-enamel junction. Thirty root segments were set in an acrylic block with the dentinal surface exposed. All root segments were irrigated with sodium hypochlorite solution before treating with test solutions. Microhardness (Vickers hardness number [VHN]) values of each specimen were determined using Vickers indenter before and after treatment with test solutions (Irritrol and EDTA). The mean lengths of the two diagonals formed due to indentation were used to compute the microhardness value. VHNs were determined using these measurements. Mean differences between (Irritrol and EDTA) and within the (before and after) group were compared using Student's t-test. Intragroup comparison was done using F-test (one-way ANOVA) at different areas of radicular dentin. α =0.05 was the set level of significance. Results: Both the test solutions showed a reduction in microhardness in coronal and middle third of root canal dentin, but the reduction in apical third (P < 0.05) was significantly more with respect to EDTA when compared to Irritrol. Conclusion: Irrigation using 17% EDTA and Irritrol decreased the root dentin microhardness; however, in the apical third, there was a less decrease in microhardness by Irritrol when compared to EDTA.

Introduction: The study aimed to compare the efficacy of a single application of plain nano-hydroxyapatite (n-HA) paste in reducing dentine hypersensitivity. Materials and Methods: Sixty-three patients were recruited to participate in the study and randomized to be allocated into three groups (n-21): (1) Group 1 – n-HA paste, (2) Group 2 – fluoride paste, and (3) Group 3 – placebo. The patient's response to dentin hypersensitivity (DH) was evaluated at baseline (T0), immediately after application (T1), and after 1 week (T2). Tactile and cold air sensitivity (CAS) stimulus tests and visual analog scale subjective tests were used to measure the patient's response to DH. The data analysis was performed using the Statistical Package for the Social Sciences statistical software. Results: All three groups showed a statistically significant reduction in tactile sensitivity (TS), cold air sensitivity, and visual analog scale scores from T0–T1 and T0–T2 (P < 0.005). However, from T1–T2, there was no significant reduction in the TS, cold air sensitivity, and visual analog scale scores of the groups (P > 0.005) except for Group 1, which showed a significant reduction (P = 0.033) in visual analog scale scores from T1–T2. However, the intergroup comparison at T2 demonstrated a significant difference in tactile scores (P = 0.005), CAS (P < 0.001), and visual analog scale scores (P < 0.001). There was no incidence of treatment-related adverse events with the study products. Conclusion: n-HA paste was the most effective desensitizing paste compared to fluoride and placebo pastes. The single application of the n-HA paste demonstrated a significant reduction in visual analog scale scores after 1-week.

Introduction: As predoctoral dental students navigate through the dental curriculum, the knowledge of clinical dentistry is progressively gained from didactic lecture courses. The goal of this study was to evaluate whether there is an association between endodontic didactic knowledge and endodontic preclinical skills. Methods: The study utilized the existing preclinical endodontic assessments of 2^nd-year dental students (105 students). Using ExamSoft, the nonclinical questions (e.g., microbiology and pulp biology) were excluded from the final didactic assessment, and a new didactic grade was calculated and assigned to each student. Each endodontic skill (access preparation, instrumentation and obturation, and combined) was matched with corresponding clinically related questions in the didactic assessment. For each student, the matched didactic grade was weighted against the practical grade using Kendall's τ correlation coefficient. To determine the effect of each predictor variable (didactic score and gender), an ordinal logistic regression was used. Results: For all portions of the examination, the correlation between preclinical and didactic grades was significant, P < 0.05, but weak. Regression analysis showed that the didactic grade coefficient was significant for access, instrumentation and obturation, and combined portions of the examination. The student's gender coefficient was not significant for any portion of the examination. Conclusion: Only a weak association was found between didactic performance and preclinical skills. Lectures on clinical topics should be improved and sequenced accordingly to better link the theory of endodontic technique to the hands-on simulation laboratory.

Introduction: This study was aimed to evaluate and compare the effectiveness of conventional posterior composites, and short fiber-reinforced composites with and without the use of glass fiber post (GFP) and polyethylene fiber post on fracture strength of endodontically treated maxillary premolar teeth. Materials and Methods: Root canal treatment was performed on the sixty extracted maxillary premolars followed by mesio-occluso-distal cavity preparation and removal of the lingual wall. The teeth were randomized into six groups (A1, A2, A3; B1, B2, and B3). In Group A, a conventional posterior composite was used as a core material, and in Group B, short fiber-reinforced composite was used. Groups A and B were divided according to the post systems used. In Groups A1 and B1, 3 mm deep cavities were prepared in the palatal canal and restored with respective core materials. In Groups A2 and B2 GFP were placed in 10 mm post space prepared in the palatal canal and restored with respective core material. While in Groups A3 and B3 polyethylene, fiber post was placed, followed by core build-up with respective core materials. Samples were subjected to fracture resistance testing in the Universal testing machine, and the fractured samples were inspected in stereomicroscope under 20× for identifying fracture patterns. The data were analyzed using one-way ANOVA, followed by post hoc Tukey's test. The failure pattern was analyzed using the Chi-square test. Results: Higher fracture resistance values were seen with groups restored with the post as compared to groups restored without post, but the difference was not statistically significant (P > 0.05). The short fiber-reinforced composite showed higher resistance values than the conventional composite (P < 0.05). No significant difference in fracture resistance was observed when the samples were restored with either of the post (P > 0.05). The use of post resulted in a significantly higher number of favorable fracture of the teeth (P < 0.05). Conclusion: The use of post did not have a profound effect on the fracture resistance but had a positive effect on failure patterns in teeth with one remaining wall. In root canal treated teeth with one wall remaining, the use of either post with short fiber reinforced composite is recommended.

Introduction: To evaluate the retreatability of Bioceramic and GuttaFlow Bioseal sealers using ProTaper Universal System Retreatment files aided by dental microscope analysis. Materials and Methods: Root canals of forty single-rooted human mandibular premolar teeth were prepared with ProTaper Next rotary system and obturated with single-cone obturation technique (n = 20 each) using EndoSequence Bioceramic root canal sealer (Group 1) and GuttaFlow Bioseal root canal sealer (Group 2). All specimens were retreated with ProTaper Universal Retreatment System files. The working time of retreatment procedure was calculated. Samples were sectioned, and the residual filling remnants were observed under dental operating microscope. Statistical analysis was performed using SPSS software. Results: The least total working time was observed in GuttaFlow Bioseal group (2.35 min). Overall, less residual filling materials was found in Bioceramic sealer group specimens in all root levels compared to GuttaFlow Bioseal group (P = 0.000, 0.022, and 0.000, respectively). Conclusion: The retreatment technique used was incapable of complete removal of filling material within root canal walls.

Introduction: This study aimed to determine the root canal configuration of mandibular incisors among a Saudi subpopulation of Qassim region using cone-beam computed tomography (CBCT). Materials and Methods: CBCT images of 94 patients aged from 13 to 69 years with 376 healthy mandibular incisors fulfilling the inclusion criteria were evaluated. The root canal configurations of the examined teeth were recorded in accordance with the Vertucci's classification for each tooth. Data were statistically analyzed. Results: All the examined mandibular incisors had a single root. Type I root canal configuration represented 44.4%, Type II 8%, Type III 44.9%, Type IV 0.5%, and Type V 2.1%. Chi-square tests showed no statistically significant association between the type of tooth and the presence of a second canal (P = 0.177). Conclusions: Within the limitations of this study, it can be concluded that a single root with two root canals of Type III was the most common root canal configuration of the mandibular incisors within a Saudi subpopulation of the Qassim region.

Introduction: The aim of the study was to evaluate the number of roots and tooth length of the maxillary and mandibular premolars of a Moroccan subpopulation using cone-beam computed tomography (CBCT). Materials and Methods: The number of roots and tooth length of 919 maxillary and mandibular premolars (358 maxillary and 561 mandibular) examined by CBCT was evaluated using “Planmeca viewer” software. Statistical analysis was carried out using the Epi info software. Results: The study showed a high prevalence of two roots for maxillary first premolars, and single root for maxillary second premolars and mandibular first and second premolars. The mean length of the maxillary first premolars (single rooted) was 21.74 mm, that of the buccal roots was 21.92 mm, and that of the lingual roots of the two-rooted teeth was 20.67 mm. The maxillary second premolars (21.4 mm) and the mandibular premolars (21.5 mm) exhibited the same mean length. Conclusion: All premolars had a single root in most cases, except for the maxillary first premolars where two-rooted teeth were more frequent with an average length of 21.4 mm. CBCT is an exciting tool for endodontic diagnosis and treatment planning.

Introduction: Endodontic emergencies are characterized by violent or disabling pain. The management of these emergencies requires a precise diagnosis and an emergency act with or without a prescription. This study primarily aimed to determine undergraduate students' knowledge on the management of endodontic emergencies at the dental school. Materials and Methods: In this cross-sectional descriptive study, students of the dental school have received questionnaires with two main parts: a first part dealing with students' identification and a second part dealing with students' knowledge and attitudes on endodontic emergency management. Participants were asked to choose the appropriate option (s) for the appropriate management of each type of endodontic emergency. Data were statistically analyzed. Results: Of the 176 students included in this study, 171 questionnaires (97.2%) were completed and returned to the authors. For each emergency, most of the respondents recommended options that are consistent with the standard protocol. The statistical analysis showed a significant correlation between correct responses according to the standard protocol and academic levels of students who attended a conference or training on endodontic emergencies and students who dealt with endodontic emergency during their training (P < 0.05). Conclusion: The study showed that the students' level of knowledge is high. However, they recommended inappropriate antibiotic prescriptions. This shows the need to improve student-training programs on endodontic emergencies.

Introduction: The aim of the study was to evaluate the bacterial leakage of four different bioceramic root canal sealers and to compare it to the conventional epoxy resin-based sealer. Materials and Methods: The study sample consisted of 94 single-rooted human teeth with one round root canal, which were instrumented and randomly distributed into five experimental groups according to the root canal sealer: Group 1: TotalFill bioceramic sealer; Group 2: BioRoot root canal sealer; Group 3: mineral trioxide Aggregate (MTA) Fillapex; Group 4: MTA Plus; Group 5: epoxy resin-based sealer AH Plus and positive and negative control group. The prepared samples were fixed in a model designed for the Enterococcus faecalis leakage evaluation and were sterilized in plasma. The bacterial penetration through the filled root canals was checked by the color change in the lower tube during 60 days. The scanning electron microscopy was used to check the bond between the sealer and the dentine wall. Data were statistically analyzed. Results: Total Fill bioceramic sealer (BCS) group presented significantly lower number of samples that leaked (14.2%) compared to the AH Plus group (78.6%) (P = 0.002) and MTA Plus group (50%) (P = 0.046). There was no statistically significant difference between other groups (P > 0.05). Conclusion: The TotalFill BCS root canal sealer provided better sealing ability compared to the AH Plus and the MTA Plus sealers.

Introduction: The aim of this study is to assess the destitution of facial root fenestration in maxillary anterior teeth among the Saudi population in cone-beam computed tomography (CBCT) scans. Materials and Methods: A total of 100 CBCT scans of maxillary anterior teeth were evaluated for the presence, location, and type of the fenestration. The age, gender, number of fenestrations, and their location was displayed by frequency and percentage. Data were statistically analyzed. Results: The overall prevalence of root fenestration in the facial bone of maxillary anterior teeth was 80%. It was higher in females (57.5%) than males. The most common tooth being affected by fenestration was lateral right incisor (35.0%). The most common type of root fenestration was Type IV (52.5%). No significant difference was found between all types of fenestrations and all age groups (P < 0.365). The highest mean of fenestration height was found in relation to the left canine (7.1 mm) and lowest was in lateral right incisor (4.9 mm). Conclusions: Females and lateral right incisor areas were the most commonly affected by the root fenestration of Type IV.

Introduction: The aim of this survey was to investigate the current knowledge and attitude toward intracanal instrument separation and the most common modality of treatment employed among endodontists and postgraduates in India. Materials and Methods: A validated web-based questionnaire that comprised close-ended and partially close-ended questions in four categories was circulated by e-mail along with the informed consent to 1100 endodontists and postgraduates. The participants were asked about the frequency of instrument separation, possible etiological factors, management, and techniques used for instrument retrieval. Reliability was checked by asking ten random participants to fill the forms twice within a time frame of 15 days. Statistical Analysis: The validity and reliability scores for the survey were calculated using content validity ratio and kappa test, respectively. All the analyses were performed using SPSS 16.0 software. Results: A total of 499 responses were received, yielding a response rate of 45.3%. The content validity ratio was 0.9 and kappa scores for reliability were 0.98. The survey respondents comprised 47.6% of endodontists and 52.4% of postgraduates. Majority of the respondents (59.5%) opted to bypass, clean, and shape the canal and incorporate the separated instrument in the obturation. Ultrasonics (60.9%) was the most preferred technique for instrument retrieval of which 28.5% of the respondents used direct ultrasonic vibrations, 23.1% used indirect vibrations, and 48.4% used both direct/indirect vibrations. Conclusions: The respondents of the survey were aware of the possible etiological factors and management techniques used for retrieval of the separated instrument. Majority of them chose to bypass the separated instrument. Ultrasonics under a dental operating microscope was the most commonly employed technique for retrieval.

Introduction: The aim was to assess the quality of root canal filling and the frequency of procedural errors in endodontic treatment performed by undergraduate students at Riyadh Elm University, Riyadh, Saudi Arabia. Materials and Methods: Radiographic record of 306 postroot canals treated anterior and posterior teeth done by female undergraduate students between 2013 and 2019 were randomly selected. The root canal filling was evaluated using the following criteria: acceptable treatment comprises the following characteristics: uniform density, no voids, root canal filling 0–2 mm from the radiographic apex, and tapered: overfilling, underfilling, and inadequate density were considered unacceptable. Data were statistically analyzed. Results: A total of 116 root canal fillings were done in the anterior teeth and 190 in the posterior teeth. In which 69.9% of root canal fillings were acceptable, and 66% of the treated teeth were in the maxilla. Patients with abscess and periapical pathology in radiograph had 2.11 times higher odds of unacceptable root canal fillings compared to patients with normal periapical radiographs, and the association was significant with 95% (confidence interval: 1.27–3.50) after adjusting for age, number of canals, tooth position, and location. About 13.7% of the unacceptable root canal fillings were underfilled. Conclusion: The quality of root canal filling performed by female undergraduates was considered acceptable. Underfilling was the mostly identified treatment error. Hence, additional preparation is needed to improve the clinical aptitudes of the undergraduates for better endodontic treatment results.

Introduction: This study aimed to evaluate the association between the number and configuration of root canals of mandibular first and second molars in an Iranian subpopulation residing in Qazvin city using cone-beam computed tomography (CBCT) scans. Materials and Methods: In this descriptive analytical study, 500 CBCT scans of patients taken for purposes other than this study were retrieved from a radiology clinic in Qazvin city, Iran. The number of roots and canals and the morphology of the root canals of 129 mandibular first and 198 mandibular second molars were studied on CBCT scans. The data were analyzed using the Monte Carlo test. Results: Most of the first (96.1%) and second (81.8%) molars had two roots. The frequency of three-rooted mandibular first molars was 3.9%. The mesial and distal roots of the mandibular first molars were mainly Vertucci's Type II (62.1%) and Type I (57.4%), respectively. In the second molars, Vertucci's Type II (61.9%) and Type I (92.3%) had the highest frequency in the mesial and distal roots, respectively. A significant association was noted between the presence of three canals and Vertucci's Type II configuration and between the presence of four canals and Vertucci's Type IV in the mesial root of the mandibular first and second molars (P < 0.05). Conclusion: There is a significant association between the number of canals and configuration of the mesial root canal of the mandibular first and second molars.

A nonsurgical root canal retreatment was initiated for the upper right second premolar in a 35-year-old healthy female patient as part of her comprehensive dental treatment. She reported severe pain during the treatment, and then the procedure was discontinued due to time limitations. The next day, she returned back to the clinic complaining of a skin injury on the right side of her face. According to the patient's history, she felt a burning sensation during the procedure when the treating clinician began using a solution from a syringe. Extraoral clinical examination revealed a dry, pink-brown skin injury extending from the right labial commissure to the middle cheek area. Since the only solution used during the first visit was chloroform, the skin injury was diagnosed as a first-degree chemical burn due to accidental chloroform skin exposure. The patient was reassured and instructed to use petroleum jelly (Vaseline) until healing was complete. After 2 weeks, the burn had healed completely without scarring, with only slight hyperpigmentation remaining in the affected area. Chloroform use should be limited to cases in which mechanical gutta-percha removal is ineffective. It should be handled with extreme caution. Chemical burns can be prevented if exposure is detected immediately and the area washed thoroughly. This clinical case is made to increase the clinicians' awareness of the hazards of chloroform.

Autotransplantation is a viable option for immediate rehabilitation of missing teeth in young patients. It aims to preserve pulp vitality and proprioception, aiding complete root formation and osseous development, resulting in esthetic outcomes. A 20-year-old healthy female patient presented with pain in relation to a grossly mutilated nonrestorable right upper second molar tooth. Due to the young age of the patient, the proposed treatment was autotransplantation of upper third molar with incompletely formed roots to rehabilitate the second molar. Following precise diagnosis and application of strictly standardized treatment protocols, the strategically chosen donor tooth was atraumatically extracted and transplanted into the recipient site causing minimal damage to the periodontal ligament cells (PDLs). Clinical and radiographic findings over the 4-year follow-up period demonstrated normal gingival healing along with gradual bone regeneration. There was continued root formation and pulp revascularization with subsequent partial pulp canal obliteration. Higher survival rates of transplanted teeth are significantly associated with strict case selection criteria and protection of PDL. An analysis of pertinent prognostic factors with a long-term follow-up is required to predict and improve the outcome of tooth transplantation.

Management of endodontic lesions in previously treated teeth might be challenging due to the presence of procedural mishaps such as metallic objects that have been broken accidently by the previous treating dentist. A 36-year-old female complaining of pain with biting was referred for endodontic retreatment of her maxillary left central incisor. The involved tooth was sensitive to percussion, and the periapical radiographic examination revealed the presence of an apical radiolucency, a lateral radiolucency, and a separated round bur in the apical third. Cone-beam computed tomographic imaging was performed to provide a detailed assessment of the tooth and the surrounding structures. The tooth was diagnosed as previously treated with symptomatic apical periodontitis. Root canal retreatment was completed using a combined surgical and nonsurgical approach under an operating microscope. At 1-year follow-up, the patient was asymptomatic, and the two-dimensional radiographic examination revealed complete healing and remained so for the 4 years of follow-up. The presence of a broken bur in a previously filled root canal is unusual. Endodontic management of such cases requires careful evaluation and good clinical management.

Failure of endodontic treatment most commonly occurs due to inability of the clinician to locate the extra root and canal present; however, at times, there could also be a fewer number of roots and canals present, especially in molar teeth. A 33-year-old healthy female reported with a chief complaint of tooth pain in her upper left first molar. Clinical examination revealed a fractured restoration and deep proximal carious lesion of the tooth. The tooth was tender on percussion and negative to thermal and electric pulp testing. Radiographic examination revealed a single root and a single canal. A diagnosis of asymptomatic irreversible pulpitis with symptomatic apical periodontitis was made. Nonsurgical endodontic treatment was performed. The patient was asymptomatic at a 6-month follow-up with no abnormalities detected radiographically. The use of cone-beam computed tomography scan was very helpful in confirming the root and canal morphology of the treated tooth.