Introduction: The influence of intracanal instrumentation technique on microcrack formation is a debatable subject. This review aimed to review the effect of different root canal instrumentation techniques (hand, continuous rotary, reciprocal rotary, adaptive, and self-adjusting file techniques) on microcracks formation and evaluate whether the incidence of cracks formation differs between destructive and nondestructive evaluation methods. Materials and Methods: All in vitro studies comparing the influence of at least two different instrumentation techniques were searched for this narrative review in PubMed, Scopus, and Google Scholar databases. The search included articles that were published from 2016 to 2020. The search was carried out by six independent reviewers in this review. Results: A total of twenty-five (n = 25) articles met the eligibility criteria. Only six studies showed the absence of new cracks development in 320 human teeth according to the instrumentation technique while the majority of the studies (n = 19) illustrated the presence of new cracks development in 1696 teeth. The results of this review showed that nondestructive methods may be less likely to cause microcracks than destructive methods. Conclusions: The number of dentinal microcracks varies depending on the type of instrumentation techniques and evaluation methods used. Therefore, in destructive evaluation methods, root canal instrumentation with hand, reciprocating, rotary, adaptive, and self-adjusting systems resulted in the development of more new dentinal microcracks than nondestructive methods.

Introduction: Re-establishing the health of the periapical tissues is considered to be the main objective of nonsurgical root canal retreatment in cases with posttreatment disease. Removal of filling material from the canal space is the most difficult and challenging step during retreatment, regardless of the technique/instrument used. The aim of this study was to determine the effectiveness of nickel–titanium reciprocating instruments in the removal of root canal filling material in comparison with continuous rotary shaping and retreatment instruments. Materials and Methods: Four electronic databases were used (PubMed, Google Scholar, ScienceDirect, and Scopus) as information sources. Articles describing in vitro studies carried out on extracted human teeth were included in this systematic review, while narrative, systematic review, in vivo studies, animal studies, studies published in languages other than English, and studies that used methods other than micro-computed tomography to detect root filling material were excluded from this systematic review. The studies were assessed for eligibility according to inclusion criteria by two independent reviewers; the opinion of the third reviewer was requested when one of the reviewers did not accept the study to be included. Results: Forty-one studies of 560 titles and abstracts screened were selected for full-text analysis; 26 studies were excluded, and 15 studies were included in this systematic review. Eleven studies (73%) showed a nonsignificant difference between reciprocating and rotary instruments. Conclusions: The collected studies showed no effect of motion (either reciprocation or full rotary motion) on the remnant of root canal filling materials.

Introduction: Cone-beam computed tomography (CBCT) is a recent advancement in diagnostic radiology in dentistry which allows the clinician to have a clear 3D view of the root canals before starting the endodontic treatment. The goal of the present research was to assess the root canal cross-sectional shape (RCCSS) in maxillary and mandibular premolars in the Saudi Arabian subpopulation. Materials and Methods: In the present study, radiographs of 330 patients who had teeth with complete root development and closed apices were selected. Root canal shapes were assessed at the coronal and middle thirds, and in the apical third, 1 mm above the apical foramen using CBCT. Categorical variables were explained as frequencies and percentages and evaluated using the Chi-square test. Results: 1666 premolars were evaluated in the study. Maxillary first and second premolars were found to have a maximum circular cross-sectional shape at the coronal, middle, and apical sections in most of them followed by flattened and oval cross-sectional shapes except the maxillary right second premolars where the most frequent RCCSS was flattened in the coronal section (71%), circular in the middle (14%), and apical (10%) section. The most recurring coronal RCCSS in mandibular first and second premolars was oval followed by flattened and circular, while the most frequent cross-sectional shape in the middle and apical sections was found to be circular followed by oval and flattened RCCSS. Conclusion: Marked variations were observed in the coronal and middle RCCSS of maxillary and mandibular premolars though the most prominent RCCSS in the apical section was the circular shape.

Introduction: This work studied the synergistic effect of chitosan and mineral trioxide aggregate (MTA) on mechanically exposed dental pulp following pulp capping in dogs' teeth. Materials and Methods: Class V cavities were prepared in 60 teeth of 3 mongrel dogs. These cavities were prepared approximately 1 mm coronal to the gingival margin by using a round carbide bur #2 with water cooling. These teeth were divided according to the pulp capping material into 2 groups (30 teeth each); Group I: MTA and Group II: a combination of MTA and chitosan compound. The cavities were restored by self-curing glass ionomer cement, followed by varnish application to provide the suitable conditions for pulpal repair. Both groups were further subdivided according to the evaluation period into 3 subgroups (10 teeth each); subgroup A: 7 days, subgroup B: 21 days, and subgroup C: 60 days. Histological evaluation of dentin bridge formation was performed after pulp capping in all subgroups. Data were statistically analyzed by ANOVA, Tukey's post hoc, Kruskal–Wallis, and Mann–Whitney U-tests. The significance level was set at P ≤ 0.05. Results: No statistically significant difference was found between both groups at all evaluation times (P > 0.05). The combination of MTA and chitosan did not improve the quality of dentin bridge produced by the MTA alone. Conclusion: Mixing of chitosan and MTA as a direct pulp capping material has no synergistic odontogenic effect in dog's teeth.

Introduction: Calcium silicate-based cement (CSC) with calcium chloride (CaCl₂) accelerator sets faster than the cement without accelerator. For endodontic microsurgery, CSC with the accelerator tends to be less soluble in tissue fluid that may improve clinical outcome. This study aimed to evaluate the outcome of endodontic microsurgery by retrofilling with CSC containing accelerator (Bio-MA) compared to the original CSC (ProRoot^® mineral trioxide aggregate [MTA]). Materials and Methods: Forty-eight teeth required surgical root canal retreatment was included according to the eligible criteria. Endodontic microsurgery with standardized protocol was performed under the dental operating microscope. Bio-MA or ProRoot^® MTA was randomly selected for retrofilling. At recall visit, treatment outcomes were evaluated as “healed,” “healing” or “diseased,” based on clinical and radiographic assessments. The Chi-square test and Fisher's exact test were used in the statistical analysis of the outcome. Results: Seven teeth were excluded because of vertical root fracture detected in surgery (n = 5) and inadequate retrofilling depth (n = 2). Two cases were lost to follow-up. For thirty-nine teeth with 14.9 ± 5.2 months recall, “healed” rates were 85% in Bio-MA and 84.2% in ProRoot^® MTA, and “healing” rates was 15% in Bio-MA and 15.8% in ProRoot^® MTA. None of “disease” was observed. No significant difference in the clinical outcome was observed between groups of Bio-MA and ProRoot^® MTA (P = 1.00). Conclusions: The endodontic microsurgery outcome of Bio-MA containing CaCl₂ accelerator was similar to that of ProRoot^® MTA without accelerator.

Introduction: Removing the secondary smear layer has been presumed to increase the micromechanical retention of fiber posts. The additional use of irrigation techniques is intended to improve the cleanliness of the root canal walls. The present study aimed to determine the effectiveness of sonic and ultrasonic irrigation techniques on root canal cleanliness after the post space preparation. Materials and Methods: A total of 27 extracted single-rooted premolar samples underwent root canal treatment using gutta-percha and AH Plus that was labeled with rhodamine B. Gutta-percha was removed during the post preparation. The sample was then divided into three groups (n = 9): irrigation with sonic activation, ultrasonic activation, or without activation, respectively. The teeth were subsequently cut in the middle third area of the root, and the remnant of smear layers was observed using a confocal laser scanning microscope. Cleanliness was expressed as a percentage of the angle that contained part of the red area representing the smear layer. The results were statistically analyzed with a one-way ANOVA test and post hoc Bonferroni test set at 5% significance level. Results: The sonic group had the greatest percentage of root canal wall cleanliness (89.00 ± 2.77), followed by the ultrasonic (78.33 ± 3.09) and nonactivated groups (67.77 ± 3.37). Conversely, there was no significant difference in root canal wall cleanliness between the sonic and ultrasonic groups (P = 0.067) or the ultrasonic and nonactivation groups (P = 0.071). Conclusions: Irrigation with sonic activation improved cleanliness of the root canal dentinal wall after post space preparation.

Introduction: Regenerative endodontic procedure (REP), a biologically based procedure, designed to restore damaged structures such as dentin, root structure, and cells of the pulp-dentine complex. Patients have started using YouTube (YT) as a source of oral information. Hence, this study was planned to appraise the educational worth of REP videos available on YT. Materials and Methods: YT search was conducted by means of the keyword “REP” which yielded 348 videos. Only 21 videos were complying with the inclusion criteria. REP-data quality score (DQS) was developed for rating the quality of these videos (0–20 points). Four-blinded evaluators reviewed and scored all videos according to REP-DQS. The global quality score (GQS) was used for the score validation. Reviewer's bias was addressed by intra-class correlation coefficient. Internal consistency of REP-DQS score was checked by Cronbach alpha. Results: Test-retest reliability of both REP-DQS and GQS scores was good which is represented by high degree of conformity between all reviewers. GQS and REP-DQS scores were found to be having a positive linear correlation. REP-DQS was not found to be correlated with any of the video characteristics such as number of views, likes-dislikes, comments, and duration of video. Conclusion: It is crucial that dental professionals acclimatize to the changing times of contemporary technology. It is the responsibility of dental professional to convey their patients about the shortcomings of YT videos with its judicious use to gain accurate information.

Introduction: The aim of the study was to investigate (a) whether patients' mouth opening influenced their discomfort during maxillary buccal infiltration (MBI) anesthesia and (b) whether dentists preferred their patients' mouth opened during MBI or closed. Materials and Methods: The protocol of this study was registered in ClinicalTrials.gov (NCT03921190). In this parallel equivalence randomized clinical trial, 120 American Society of Anesthesiologists I or II adult patients with a maxillary posterior tooth diagnosed with irreversible pulpitis and normal apical tissues and scheduled for root canal treatment were included and randomly divided into two groups using a coin toss; Group A (n = 56) received MBI with an open mouth, while Group B (n = 64) were injected using a closed-mouth technique. Patients with psychological disorders, soft-tissue abnormalities, tenderness to palpation, or percussion, and those who used analgesics 12 h before the appointment were excluded. Patients rated their discomfort during needle penetration, cheek retraction, and their overall discomfort using a standard 100 mm visual analog scale (VAS). Furthermore, 50 practicing dentists assessed (on a standard 100 mm VAS) the visibility of the injection site and ease of cheek retraction during MBI using either technique and chose their preferred technique. Data were analyzed using the Student's t, independent sample t, and the Chi-square tests. Results: The mean discomfort experienced in Groups A and B were 32.4 and 31.6 upon needle penetration (P = 0.84), 28.9 and 18.9 upon cheek retraction (P < 0.001) and 32.6 and 25.0 throughout the injection procedure (P < 0.001), respectively. Out of 48 dentists who returned the completed forms, 38 dentists reported that they preferred the closed-mouth technique for MBI (P < 0.001). Conclusions: The closed-mouth technique of MBI anesthesia results in less patient discomfort and improved visibility.

Introduction: Bioceramic root canal sealers are the newest generation of root canal sealers. Τhere are contradictory results in the literature about their antimicrobial activity. The aim of the study was to evaluate the antimicrobial efficacy of four root canal sealers against Enterococcus faecalis. Materials and Methods: Four root canal sealers were used in order to examine antibacterial efficacy: TotalFill, BioRoot Root Canal Sealer, mineral trioxide aggregate (MTA) Fillapex, and AH Plus. The bacterial suspension was placed on a freshly mixed sealer, one or 3 days set sealer in vertically held microtiter plates. After incubation of 2, 5, 20, and 60 min in 100% humidity at 37 C, Trypticase Soy Broth was added to each well and mixed. Then, bacterial suspension from each well was transferred, serially diluted, and placed on Mitis salivarius agar plates. After incubation, colony-forming units were counted. All experiments were performed in triplicate. The outcomes of antimicrobial properties of tested materials were analyzed by one-way analysis of variance. Results: All bioceramic root canal sealers showed significantly better efficacy than the control group and epoxy resin sealer (P < 0.05). TotalFill presented the highest efficacy comparable with BioRoot RCS (P > 0.05), followed with MTA Fillapex (P < 0.05). Also, freshly mixed sealers showed comparable efficacy as sealers set for 3 days (P > 0.05), but better than sealers set for 1 day (P < 0.05). All sealers exhibited the highest efficacy after 20 min of contact time, independently of materials that were freshly mixed or set for 1 or 3 days. Conclusion: Bioceramic sealers have greater antimicrobial activity than commercially used epoxy resin sealer. These sealers exhibited the strongest efficacy at 20 min of contact time, independently of their setting condition.

Introduction: Endodontic instrument separation is one of the iatrogenic errors which may affect the outcome of treatment. The present in vitro study was aimed to investigate the effect of different cross-sectional designs of separated nickel–titanium (Ni-Ti) rotary files on apical microleakage. Materials and Methods: A total of 48 mandibular premolar roots were selected. The samples were randomly assigned to four experimental groups including Mtwo (n = 10), HERO Shaper (n = 10), RaCe (n = 10), and FlexMaster (n = 10) as well as positive (n = 4) and negative (n = 4) control groups. Ni-Ti rotary instruments with the same size and taper (0.06, #30) were separated in the apical region after complete cleaning and shaping, and the remaining root canal was obturated with gutta-percha and AH-26 sealer. The bacterial microleakage of each group was assessed through Enterococcus faecalis for 60 days. Survival analysis was done by SPSS 22. Results: There were no statistically significant differences between the studied groups in terms of the time of microleakage (P = 0.955). Conclusion: The separated Ni-Ti rotary instruments with different cross-sectional designs had no impact on apical microleakage.

Introduction: This research aimed to examine and compare the effect of two calcium silicate sealers with AH plus resin sealer on collagen extraction and surface collagen degradation of dog's root dentin, using different irrigants. Materials and Methods: In vitro part; 180 standardized root dentin cylinders obtained from dog's incisors were randomly allocated into three groups (n = 60) according to the final irrigant used; Group A: 17% Ethylenediaminetetraacetic acid, Group B: 2.5% NaOCl, Group C: 0.9% saline. Each group was classified into 4 subgroups (n = 15) according to the type of sealer used for obturation; subgroup 1: BioRoot RCS, subgroup 2: Total Fill BC, subgroup 3: AH Plus sealer, and subgroup 4: Unfilled (control). After preparation, irrigation, obturation, and aging in a storage medium; hydroxyproline (HYP) released in the medium was determined after 1 day, 1 and 3 months using spectrophotometer. In vivo part, sixty incisors of five dogs were randomly allocated as in the vitro part into three groups and four subgroups in accordance to the type of irrigation and sealer used. After 3 months of preparation, irrigation, and obturation, dogs were euthanized and teeth were extracted for the assessment of surface collagen degradation using scanning electron microscope. HYP released was analyzed using repeated-measures analysis of variance and post hoc of Bonferroni. Surface collagen degradation was analyzed using Kruskal–Wallis test and Dunn's test. Results: BioRoot RCS and TotalFill BC showed a significant higher (P < 0.001) HYP release and surface collagen degradation than AH plus sealer and control with all irrigants. Conclusions: Calcium silicate sealers significantly affected the collagen microstructure of dentin surface. AH Plus resin sealer has no effect on collagen dissolution or microstructure.

Introduction: The purpose of this survey was to assess the concentration of chlorine in sodium hypochlorite solutions (NaOCl) used as root canal irrigation solutions by the dentists in Marrakech, Morocco. Materials and Methods: A survey was carried out among 74 practitioners registered with the Moroccan Order of Dentists, of whom 36 (48.6%) were men and 38 (51.4%) were women. A self-administered questionnaire was used. Among the questions, participants were asked about the number of treatments performed per week, the type of irrigation solution used, and the storage of the irrigation solution. After this interview, a 30 mL sample of that solution was sent to a laboratory to determine the amount of chlorine by iodometric titration. Jamovi version 1.8.1/ANOVA and the t-test were used to perform the statistical analysis (P < 0.05). Results: All the practitioners except two used the NaOCl as an irrigant. Besides, 84.7% prepared their solutions. The solutions were stored 63.8% of the time in opaque containers. The mean percent of chlorine concentration was 0.95% ± 0.68%. The concentration was also higher in the ready-to-use solutions (1.39%) than those prepared in the office (0.87%). Moreover, this difference was statistically significant (P = 0.01). Conclusion: The results confirmed that the NaOCl is the solution that practitioners use mostly. The conditions of dilution and storage are inappropriate, and the concentration is very low at 0.95%.

Introduction: The use of intracanal cryotherapy in the reduction of postendodontic pain (PEP) has been investigated in several recent scientific publications. This study aims to compare the effect of intracanal cryotherapy at three different temperature ranges (room temperature, 2°C–4°C and 13°C–15°C) on PEP. Materials and Methods: A parallel, double-blind randomized clinical trial was conducted at SEGi University, Malaysia. This trial included 51 participants who were diagnosed with symptomatic irreversible pulpitis and symptomatic apical periodontitis in single-rooted teeth. The root canal therapy was completed in single visit for all the patients. Prior to the obturation step, they were randomly allocated into three groups of 17 participants each (Group 1: room temperature [control], Group 2: 2°C–4°C, and Group 3: 13°C–15°C). The intracanal cryotherapy was performed over a period of 5 min. The PEP scores were measured using Wong Baker Faces Pain Rating Scale and recorded at different time intervals (6, 24, 48, and 72 h), and the data were statistically analyzed. Results: Kruskal–Wallis test showed statistically significant difference in mean pain ranks between at least two out of three groups studied at 24 and 48 h (P ≤ 0.05). At 24 and 48 h, the pairwise post hoc Dunn test with Bonferroni adjustments showed statistically significant difference in pain scores within the Groups 1 versus 3 (room temperature vs. 13°C–15°C) and Groups 1 versus 2 (room temperature vs. 2°C–4°C) (P ≤ 0.05), while within the Groups 2 versus 3 (2°C–4°C vs. 13°C–15°C), there was no statistically significant difference. Conclusion: Intracanal cryotherapy with 13°C–15°C saline is as effective as 2°C–4°C saline in reducing PEP and can be easily incorporated as one of the steps of root canal therapy.

Objectives: To investigate, by an in vitro study, the fracture strength of root-filled teeth restored with polyetheretherketone (PEEK) full-coverage crowns. Materials and Methods: Two single-rooted maxillary second premolar Typodont teeth were prepared according to the standardized preparation guidelines for two different full-coverage crown restorations: computer-aided design/computer-aided manufacturing monolithic lithium disilicate crowns (E.max) for the control samples and machine pressed monolithic PEEK crowns for the test samples. Teeth were duplicated in a polyurethane-based resin, with properties analogous to human dentin; n = 5 for each category. Replicas were embedded in polyurethane-based resin material using a retaining copper ring, with a simulated 200-μ periodontal ligament. Subsequently, all samples received orthograde root canal treatment using standardized preparation and obturation techniques. Crowns were cemented with resin-modified glass ionomer cement using a standardized cementation force. All teeth were subjected to a monotonic, axial static load of 2500 N to the point of fracture. Results: All control group samples displayed failure as a combined crown/tooth fracture. The crowns in the test group samples (PEEK) did not fracture under the experimental loads. Under the maximum loads, the crowns exhibited plastic deformation visible as an indentation created on the occlusal surface. Subsurface cohesive damage of the interface cement was noted. T-test showed that the resistance to fracture of the test group compared to the control group was highly significant (P < 0.001). Conclusions: Within the limitations of this study, PEEK crowns help preserve the remaining tooth structure and provide more predictable protection when compared to E.max crowns. They demonstrate failure by surface deformation and subsurface cohesive damage to the interface cement layer. It is unknown if this failure mode would occur under normal masticatory loads.

Introduction: The understanding of canal morphology helps the clinician to conduct endodontic procedures effectively. The aim of the study was to assess the morphological variations in canals of maxillary premolars, and categorize them in accordance with Vertucci's classification. Materials and Methods: Cone-beam computerized tomography (CBCT) images were taken from the archives of Islamabad Diagnostic Center. Investigations were carried out by employing CBCT images of 120 individuals. The images of maxillary first (n = 203) and second premolars (n = 205) were analyzed in the axial, sagittal, and coronal planes. The number of canals, roots, and categorization as per the Vertucci's classification was recorded. Data were statistically analyzed by using SPSS 23. Results: The 88.7% maxillary first premolars were found to have two roots and 78% of second premolars were single rooted. The most common Vertucci configuration among first premolars was Type IV (55.3%) and second premolars were Type I (66.8%). The gender-wise difference in the frequency of one- and two-rooted second maxillary premolars was statistically significant (P = 0.01). The gender-wise difference in the frequency of different Vertucci subclassifications for the second maxillary premolars teeth was statistically significant (P = 0.01). Conclusion: The maxillary premolars showed configuration variations in the Pakistani subpopulation.

Introduction: The aim of this study was to compare the vibration/oscillation frequencies of WaterPik and EndoActivator devices and their effectiveness in smear layer (SL) removal. Materials and Methods: The root canal of 60 single-rooted extracted human premolars were prepared until ProTaper Universal F2 file, and randomly grouped according to the irrigation activation technique used: EndoActivator group; WaterPik group; manual dynamic agitation (MDA) group; and control group (conventional irrigation with no activation). The vibration/oscillation frequencies of EndoActivator and WaterPik devices were measured using a digital tachometer. Electron microscopy images of all specimens were evaluated for SL removal according to a modified Hülsmann scoring system. Data were statistically analyzed. Results: The mean vibration frequency of the EndoActivator was significantly higher than that of WaterPik (200.6 ± 2.1 and 185.2 ± 2.744 Hz, respectively). A significant difference was detected in the SL removal along the full length of the canal between the experimental and control groups (P < 0.001). EndoActivator and MDA groups had significantly more samples with no to minimum SL at the coronal and middle thirds compared to the apical third, whereas there was no significant difference among the thirds in the WaterPik group. At the apical third, the WaterPik group had significantly more samples with no to minimum SL (60%) than WaterPik and MDA groups (20% and 26.7%, respectively). Conclusion: WaterPik was as effective as MDA and EndoActivator in SL removal, with better performance at the apical third, probably attributed to the lower vibration/oscillation frequency of WaterPik.

Introduction: The heat during autoclave process affects the fracture resistance of the nickel–titanium rotary file and might exert some effect on its mechanical properties. This study aimed to evaluate the effect of autoclave sterilization on cyclic fatigue of EdgeTaper Platinum^® and ProTaper Gold^®. Materials and Methods: Forty new files from EdgeTaper Platinum^® and ProTaper Gold^® rotary files with a #25 tip size were used in this study. Each system was subdivided into four groups according to the sterilization cycle; Group 1: No sterilization, Group 2: Two cycles of sterilization, Group 3: Five cycles, and Group 4: Ten cycles. Cyclic fatigue was evaluated using an artificial stainless steel canal with 60° of curvature and 5 mm radius of curvature at 37°C. The number of cycles to failure (NCF) was calculated and compared using Kruskal–Wallis test and Mann–Whitney U-test. The surface of the fractured file was evaluated with scanning electron microscopy. Results: There were significant differences within the two file brand subgroups regarding the NCF (P > 0.05). ProTaper Gold^® also revealed no significant differences in NCF (P > 0.05) related to the sterilization conditions. In addition, EdgeTaper Platinum^® showed significantly higher cyclic fatigue resistance than ProTaper Gold^® in all groups of this experiment (P < 0.05). The fractured plane showed typical features of cyclic fatigue failure for all instruments. Conclusion: Autoclave sterilization did not affect cyclic fatigue resistance of both EdgeTaper Platinum^® and ProTaper Gold^® in all groups of the experiment. When compare in each group of this experiment, EdgeTaper Platinum^® exhibited higher cyclic fatigue resistance than ProTaper Gold^®.

The present case series aims to describe the management of teeth with pulp canal obliteration (PCO) using the novel static-guided endodontic technique. Traumatic dental injury may result in partial or complete PCO, with and without periapical rarefaction and pose challenges during endodontic management. Three young adolescent patients presented to the department with a chief complaint of pain/discoloration/broken upper front teeth. The teeth were tender on percussion. Thermal and electrical pulp tests were negative for the concerned incisors. The periapical radiographic examinations revealed PCO and signs of periapical changes. A diagnosis of pulp necrosis; symptomatic apical periodontitis was established and nonsurgical endodontic treatment using the guided endodontic approach was planned with the patient consent. A cone-beam computed tomography (CBCT) scan and intraoral scanning were obtained using the special software to facilitate guided endodontics procedure. The surgical guides and a customized drill were fabricated. The drilling depth for the access to the calcified part was established using CBCT data, ensuring straight-line access. Conventional root canal treatment was completed. One-year follow-up examination revealed the absence of pain and periapical healing. In complicated cases with PCO and apical periodontitis, a CBCT and “Guided Endodontics” could be useful to save the tooth with minimal destruction of tooth structure and increase the chances of endodontic success.

The aim of this case report was to describe a successful repair of a long-standing furcal and coronal root perforation with grade II furcation involvement in the mesiolingual canal of a lower first molar. A 41-year-old male patient reported with the chief complaint of mild intermittent pain and pus discharge from mandibular left first molar for 1 year. Upon clinical and radiographic examination, a pulpal diagnosis of previously initiated therapy with root perforation was made. In addition, the tooth had a periapical diagnosis of chronic apical abscess, as well as a primary endodontic and secondary periodontal lesion with grade II furcation involvement. Root canal treatment and surgical repair of the perforation and furcation involvement with Mineral Trioxide Aggregate and bone graft was done. Recall examination after 2 years showed no evidence of periodontal breakdown. The patient was asymptomatic, and favorable bone regeneration and periodontal healing were seen on the radiograph. A literature review was also conducted to assess the factors affecting the prognosis of perforation repair in molars. Long-standing cervical root and furcal perforations readily lead to persistent endo-perio lesions and have been found to have the worst prognosis. A biocompatible sealing of the perforation site along with periodontal regeneration effectively enhances the longevity of such teeth. Though there are very few case reports that advocated the use of guided tissue regeneration for periodontal regeneration, nevertheless it has proven to be a reliable technique to improve the prognosis for crestal level and furcal root perforations.

This paper discussed a patient with dens invaginatus (DI) in all maxillary incisors that was accompanied by supernumerary tooth and also bifid cingulum, lingual pit, and talon cusp on the other teeth. DI is a rare developmental malformation usually seen in the maxillary lateral incisors of permanent dentition. A healthy 22-year-old Iranian woman was referred for the treatment of carious teeth. Following comprehensive clinical and radiographic examination, that was diagnosed DI affecting all maxillary central and lateral incisors. Left maxillary central incisor was Type I and the other incisors were Type II, according to Oehlers classification. Furthermore, she had supernumerary tooth and Class III malocclusion. All teeth responded to sensibility tests, except right maxillary central incisor that was diagnosed pulp necrosis and asymptomatic apical periodontitis. Conventional root canal therapy was done for the right maxillary central incisor using mineral trioxide aggregate and gutta percha and AH26 sealer by thermoplastic method. After 18 months of follow-up, clinical and radiographical examination revealed periapical healing of the right maxillary central incisor and absence of pulp and periapical pathosis in other incisors. The early recognition of DI, correct diagnosis, and appropriate management of this tooth is essential to ensure favorable treatment outcome.