Root and root canal morphology of permanent mandibular first and second molars in a Kuwaiti population: A retrospective cone-beam computed tomography study.

Aim: Endodontic diseases typically affect the mandibular molars. Understanding the complex morphology of the root canal system and its variations is necessary for successful endodontic treatment. The aim of this study was to evaluate the morphology of roots and root canals of mandibular first and second permanent molar teeth in a Kuwaiti population using cone-beam computed tomography (CBCT). Materials and methods: CBCT images of 651 mandibular first and second molar teeth were obtained from specialist government dental centers. The age, sex, root canal configuration, and number and type of roots were recorded. The data were statistically analyzed. Results: The most common canal configuration in the mandibular first and second molars was type II (65.6% and 54.4%, respectively), with no significant difference seen between the sexes (p = 0.234). The canal configuration was significantly different between the mandibular first and second molars (p < 0.001). Most teeth had two roots (94.5%); split roots were common (92.6%) and the number thereof varied significantly. Radicular grooves were most common on the lingual side (4.9%). C-shaped canals were present in 43 (6.60%) teeth. Additionally, one tooth had a confluent middle mesial canal and nine (1.4%) had radix entomolaris. Conclusion: Mandibular molars in our Kuwaiti population typically had two split roots with type II and IV canal configurations. The prevalence rates of C-shaped canals, middle mesial canals, and radix entomolaris were remarkably low.

Outcomes of furcal perforation management using Mineral Trioxide Aggregate and Biodentine: a systematic review.

Furcal perforation is an iatrogenic or pathologic communication between the pulp chamber floor and the alveolar bone. The outcome of perforation sealing depends greatly on the tissue compatibility and bioactivity and sealing properties of the repair materials. Mineral trioxide aggregate (MTA) and Biodentine are currently the most used materials to treat this condition. The present systematic review aimed to report the treatment outcome of repaired furcal perforation using MTA and Biodentine and identify which material would yield a better outcome. METHODOLOGY: A comprehensive search was conducted using the PubMed database to identify experimental studies and case reports that describe treatment of furcal perforation. Studies and case reports that evaluated the outcome of repaired furcal perforations using MTA and Biodentine, published in English from 2018 to April 2022, were identified. Unavailable full texts were excluded. RESULTS: Initial screening of 724 articles (670 studies and 54 case reports). After discarding the duplicated studies, we reviewed 50 studies, selecting 13 for abstract analysis. We retrieved and evaluated full texts of eight studies and five case reports. Both materials had an equivalent success rate in the first three months but by 12 months Biodentine performed better than MTA clinically and radiographically. CONCLUSIONS: Repair of furcal perforation with Biodentine yields a better outcome compared to MTA.

Three-dimensional evaluation of root canal morphology of maxillary first premolars: Micro-computed tomographic study.

Aim: The aim of this in vitro study was to investigate the root and root canal morphology of maxillary first premolar teeth in a Kuwaiti population using micro-computed tomography (µ- CT). Materials and methods: A total of 100 maxillary first premolars were scanned in a micro- computed tomographic device. The external anatomy (number of roots, distance from cementoenamel junction to apex, and presence of a palatal groove) and internal anatomy (number of canals and presence of apical deltas, lateral canals, and isthmi) of teeth were analyzed using descriptive analysis. Results: The number of roots was one root (57 %), two roots (41 %), and three roots (2 %). The longest and shortest roots measured 17.7 and 11.2 mm, respectively. The palatal groove was present in 63.4 % of the teeth. According to Vertucci's classification, type IV configuration was the most prevalent (53 %), followed by type II. A new root canal configuration type (1-2-1-2-1) was detected. Apical deltas, lateral canals, and isthmi were present in 33 %, 48 %, and 21 % of teeth, respectively. Conclusion: Type IV canal configuration was the most common root canal configuration. A new root canal configuration type IX for (1-2-1-2-1) was proposed for Kuwaiti population. The µ-CT device could to be a better diagnostic tool for understanding the anatomy of the root canal system.

Clinical and radiographic outcomes of regenerative endodontic treatment performed by endodontic postgraduate students: a retrospective study.

Objectives: Regenerative endodontic treatment is a clinical procedure aimed at biologically regenerating damaged root canal tissue of immature permanent teeth. This study aimed to report the outcomes of regenerative endodontic treatment performed by endodontic postgraduate students. Materials and Methods: Clinical and radiographic data of 27 patients, aged 10-22 years, who underwent regenerative treatment of immature permanent teeth from 2015 to 2019 were followed up, wherein clinical and radiographic examinations were performed for each patient. Postoperative success rate and tooth survival were analyzed, and the postoperative radiographic root area changes were quantified. Results: A total of 23 patients attended the dental appointments, showing that all teeth survived and were asymptomatic. Specifically, 7 periapical pathosis cases were completely healed, 12 were incompletely healed, and 4 cases failed. Moreover, significant differences were found between discolored and non-discolored teeth, and between the presence or absence of periapical radiolucency. Additionally, 3 anterior teeth showed complete closure of the apical foramen, while the apical foramen width was reduced in 17 teeth and failed in 3 teeth. Root length was also found to have been increased in 7 anterior and 4 posterior teeth, and the average length ranged from 4.00-0.63 mm in the anterior teeth, 2.85-1.48 mm of the mesial root, and 2.73-2.16 mm of the molar teeth distal root. Furthermore, calcified tissue deposition was observed in 7 teeth. Conclusions: A favorable outcome of regenerative endodontic treatment of immature permanent teeth with necrotic pulp was achieved with a high survival rate.

Outcomes of furcal perforation management using Mineral Trioxide Aggregate and Biodentine: a systematic review

Abstract Furcal perforation is an iatrogenic or pathologic communication between the pulp chamber floor and the alveolar bone. The outcome of perforation sealing depends greatly on the tissue compatibility and bioactivity and sealing properties of the repair materials. Mineral trioxide aggregate (MTA) and Biodentine are currently the most used materials to treat this condition. The present systematic review aimed to report the treatment outcome of repaired furcal perforation using MTA and Biodentine and identify which material would yield a better outcome. Methodology: A comprehensive search was conducted using the PubMed database to identify experimental studies and case reports that describe treatment of furcal perforation. Studies and case reports that evaluated the outcome of repaired furcal perforations using MTA and Biodentine, published in English from 2018 to April 2022, were identified. Unavailable full texts were excluded. Results: Initial screening of 724 articles (670 studies and 54 case reports). After discarding the duplicated studies, we reviewed 50 studies, selecting 13 for abstract analysis. We retrieved and evaluated full texts of eight studies and five case reports. Both materials had an equivalent success rate in the first three months but by 12 months Biodentine performed better than MTA clinically and radiographically. Conclusions: Repair of furcal perforation with Biodentine yields a better outcome compared to MTA.

Histologic, Radiographic, and Micro-Computed Tomography Evaluation of Experimentally Enlarged Root Apices in Dog Teeth with Apical Periodontitis after Regenerative Treatment.

BACKGROUND: Blood clot (BC) and platelet-rich fibrin (PRF) has been successfully used to biologically treat immature roots. It is nowadays considered the treatment of choice. OBJECTIVE: This study aimed to determine the ability of PRF and BC scaffolds to enhance regeneration of disinfected root canals and healing of apical periodontitis within experimentally enlarged canal apices of dog teeth. METHODS: Forty-eight root canals in 28 mandibular premolars from 4 healthy adult dogs were experimentally infected and developed apical periodontitis. The teeth were randomly divided into a control (untreated) group, a disinfection only group, a group that received disinfection and a BC scaffold, and a group that received disinfection and a BC + PRF scaffold. Healing of the apical radiolucency was evaluated by conventional radiography, micro-computed tomography, and histology after 3 months. The data were analyzed by χ2 test. RESULTS: Healing was achieved in 49% of roots as seen on radiograph and 43% as seen on micro-computed tomography. There was no significant between-group difference in the presence or absence of periapical radiolucency in the mesial roots when seen on conventional images (P = 0.255), but there was a significant difference in the distal roots (P = 0.001); similarly, on micro-computed tomography, there was no significant between-group difference in the mesial roots (P = 0.174) but there was a significant difference in the distal roots (P = 0.001). Histologically, apical closure was significantly not greater in the BC + PRF scaffold group than in the BC scaffold group (P = 0.001). CONCLUSIONS: A mix of BC + PRF scaffold did not improve tissue regeneration in experimentally enlarged dog teeth. (Curr Ther Res Clin Exp. 2021; 82:XXX-XXX) © 2021 Elsevier HS Journals, Inc.

Retreatability of Bioceramic Sealer Using One Curve Rotary File Assessed by Microcomputed Tomography.

AIM AND OBJECTIVE: This article aims to evaluate the residual filling materials after retreatment of bioceramic sealer used in the obturation technique of mandibular molars with different root curvatures using microcomputed tomography (micro-CT). MATERIALS AND METHODS: A total of 106 canals of mandibular molar teeth with closed apex, no fracture, calcification, or previously root canals treated were selected. Each tooth was mounted in acrylic resin blocks, and canals were instrumented with 06 One Curve rotary file and filled with gutta-percha and EndoSequence bioceramic (group A) or AH Plus sealer (group B) then subdivided into three groups (each) based on the degree of root curvature; mild (≤15°), moderate (16-30°), or severe (≥31°). Retreatment was done with the same rotary file. Samples were scanned before and after retreatment, and the volume of the residual materials was calculated. Data were statistically analyzed. RESULTS: The micro-CT scans show remaining filling in all canal levels of the two groups after retreatment. The mean values of all canals in bioceramic as well as AH Plus samples were significantly higher at coronal level (p < 0.001). In addition, the mean differences of distolingual canal after retreatment were not significantly different between the three levels in bioceramic group (p = 0.051). In regard to the AH Plus group, the mean values of mesiolingual canal after retreatment were statistically significant higher at coronal level (p < 0.001). CONCLUSION: Micro-CT tool provides a clear 3D visualization. Remnants of Bioceramic and AH Plus sealers were detected in different canal curvatures. The use of One Curve rotary file did not improve the removal of the filling materials. CLINICAL SIGNIFICANCE: It is difficult to achieved complete removal of bioceramic filling material from the root canal system using rotary file.

Root and Canal Morphology of Mandibular Premolar Teeth in a Kuwaiti Subpopulation: A CBCT Clinical Study.

OBJECTIVE: To study the root and root canal morphology of mandibular premolars in a Kuwaiti subpopulation using cone-beam computed tomography (CBCT). METHODS: 152 CBCT images were obtained from the radiology department archives of four dental centers in Kuwait. A total of 476 mandibular premolar teeth were analyzed by two observers. The number of roots, root canal configuration types and canal curvature measurements were examined. The relationship between sex, tooth position, and incidence of an additional canal were compared using the chi-square test, and the level of significance was set at 0.05 (P=0.05). RESULTS: The number of roots in mandibular first premolars was one in 73.9%, two in 24.9%, three and four in 1.2%. On the other hand, the number of roots in mandibular second premolars was one in 79.2% and two in 20.8%. Based on Vertucci's classification system, 18.7% of the teeth were type II followed by type VI (14.3%). The majority of the examined teeth were straight (74.8%) and the incidence of distal root angulation was about 21%. Canal configurations not included in the Vertucci classification were reported in 102 teeth (21.4%). Variability was significantly higher in the second premolars compared to first premolar (P<0.05). CONCLUSION: The Kuwaiti population has complex root canal morphology in mandibular premolar teeth.

The prevalence of radix molaris in the mandibular first molars of a Saudi subpopulation based on cone-beam computed tomography.

OBJECTIVES: The purpose of this study was to determine the incidence of radix molaris (RM) (entomolaris and paramolaris) in the mandibular first permanent molars of a sample Saudi Arabian subpopulation using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 884 CBCT images of 427 male and 457 female Saudi citizens (age 16 to 70 years) were collected from the radiology department archives of 4 dental centers. A total of 450 CBCT images of 741 mature mandibular first molars that met the inclusion criteria were reviewed. The images were viewed at high resolution by 3 examiners and were analyzed with Planmeca Romexis software (version 5.2). RESULTS: Thirty-three (4.5%) mandibular first permanent molars had RM, mostly on the distal side. The incidence of radix entomolaris (EM) was 4.3%, while that of radix paramolaris was 0.3%. The RM roots had one canal and occurred more unilaterally. No significant difference in root configuration was found between males and females (p > 0.05). Types I and III EM root canal configurations were most common, while type B was the only RP configuration observed. CONCLUSIONS: The incidence of RM in the mandibular first molars of this Saudi subpopulation was 4.5%. Identification of the supernumerary root can avoid missing the canal associated with the root during root canal treatment.

Prevalence of apical periodontitis and quality of root canal treatment in an adult Saudi population.

OBJECTIVES: To determine the health status of periradicular tissue and the quality of root canal fillings in an adult Saudi population attending dental clinics for the first time. Methods: This cross sectional study was conducted  in the dental clinics at King Saud University, Riyadh and other dental centers (Jeddah, Najran, and Albaha City), Kingdom of Saudi Arabia between year 2010   and 2012. Good-quality panoramic radiographs of 926 Saudi subjects (540 males and 386 females)were analyzed based on the gender, age, health status, smoking habits, periapical status of the endodontically treated teeth, technical quality of the root canal fillings, and the presence or absence of coronal restoration. Data were calibrated and statistical analyses were performed using the Statistical Package for the Social Sciences (SPSS Inc., Chicago, IL, USA) version 17.  Results: Of the 25,028 teeth examined, 1,556 teeth (6.2%) had apical periodontitis (AP). Male subjects aged over 55 years and females between 36 and 45 years had higher AP. A total of 36 diabetic and 87 smokers subjects had AP. The AP was more common in male diabetics than female (p=0.383), and in female smokers more than male (p=0.44). Only 42.2% of male and 57.7% of female teeth had adequate root canal treatment.  Conclusions: Apical periodontitis was significantly related to diabetes, smoking, and inadequate endodontic treatment.

Retreatment of failed regenerative endodontic of orthodontically treated immature permanent maxillary central incisor: a case report.

A revascularization procedure was shown to be the best alternative therapy for immature teeth with necrotic pulp and apical infection. A 12 year old female with a history of trauma to her upper central incisor and a sinus tract was referred for endodontic treatment. She was an active orthodontic patient and had undergone regenerative endodontic treatment for the past 2 years. Clinical examination revealed no response to sensibility, percussion, and palpation tests. The preoperative radiograph showed an open apex and apical rarefaction. The case was diagnosed as previously treated tooth with asymptomatic apical periodontitis. Regenerative endodontic retreatment was performed, and the case was followed for 3 years. Clinical, radiographic, and cone-beam computed tomography follow-up examination revealed an asymptomatic tooth, with evidence of periapical healing and root maturation.

Pulp revascularization of immature maxillary first premolar.

An immature maxillary first premolar in an 8-year-old female was treated using a regenerative approach. The root canal was gently irrigated with 5.25% sodium hypochlorite without instrumentation under aseptic conditions and then medicated with calcium hydroxide (Ca[OH]2) for 3 weeks. The Ca(OH)2 was removed, and bleeding was initiated mechanically using a hand file to form an intracanal blood clot. Mineral trioxide aggregate was placed over the blood clot, and the access cavity was sealed with a double filling. Increases in root length and width were radiographically evident, at the 6-month follow-up exam. The case was followed for 3 years. The development of 3 roots with complete apical closure was confirmed using cone beam computed tomography.

Microorganism penetration in dentinal tubules of instrumented and retreated root canal walls. In vitro SEM study.

OBJECTIVES: This in vitro study aimed to investigate the ability of Candida albicans (C. albicans) and Enterococcus faecalis (E. faecalis) to penetrate dentinal tubules of instrumented and retreated root canal surface of split human teeth. MATERIALS AND METHODS: Sixty intact extracted human single-rooted teeth were divided into 4 groups, negative control, positive control without canal instrumentation, instrumented, and retreated. Root canals in the instrumented group were enlarged with endodontic instruments, while root canals in the retreated group were enlarged, filled, and then removed the canal filling materials. The teeth were split longitudinally after canal preparation in 3 groups except the negative control group. The teeth were inoculated with both microorganisms separately and in combination. Teeth specimens were examined by scanning electron microscopy (SEM), and the depth of penetration into the dentinal tubules was assessed using the SMILE view software (JEOL Ltd). RESULTS: Penetration of C. albicans and E. faecalis into the dentinal tubules was observed in all 3 groups, although penetration was partially restricted by dentin debris of tubules in the instrumented group and remnants of canal filling materials in the retreated group. In all 3 groups, E. faecalis penetrated deeper into the dentinal tubules by way of cell division than C. albicans which built colonies and penetrated by means of hyphae. CONCLUSIONS: Microorganisms can easily penetrate dentinal tubules of root canals with different appearance based on the microorganism size and status of dentinal tubules.

An in vitro evaluation of antifungal activity of bioaggregate.

OBJECTIVE: The aim of this study was to evaluate, in vitro, the antifungal effect of bioaggregate (BA) against Candida albicans by using the direct contact method. STUDY DESIGN: BA was tested freshly mixed and after 24-hour set on C. albicans. The tested BA was incubated with C. albicans in plastic tissue clusters for 1 hour, 24 hours, and 3 and 5 days. Aliquots of 0.1 mL were taken from each well at the end of the incubation periods and transfered to tubes containing 5 mL fresh Sabouraud broth. All tubes were vortexed and then incubated at 37°C and observed for the subsequent 5 days. Growth of the fungi was observed daily by the presence of turbidity in the tubes. The results were statistically analyzed by using Kaplan-Meier test. RESULTS: The freshly mixed and set BA had no antifungal effect at 1 and 24 hours of contact. Both mixes demonstrated complete fungicidal activity after 24 hours' contact. Statistical analysis showed a highly significant difference between the negative and positive control groups (P < .001) and a significant difference between the freshly mixed and 24-hour set BA groups (P < .001) at 24 hours. CONCLUSIONS: BA (freshly mixed and 24-hour set) was effective against C. albicans after 24 hours.

Effectiveness of a 2% chlorhexidine solution mixed with calcium hydroxide against Candida albicans.

The purpose of this investigation was to examine the in vitro susceptibility of Candida albicans to a mixture of chlorhexidine and calcium hydroxide using a tube dilution test. A suspension containing C. albicans was exposed to 2% chlorhexidine solution, calcium hydroxide paste and 2% chlorhexidine mixed with calcium hydroxide in plastic tissue culture wells. The tested agents were incubated with C. albicans for 1, 24, or 72 h. All agents were effective anti-fungals at all experimental time periods tested, with the exception of exposure to calcium hydroxide for 1 h. A mixture of 2% chlorhexidine and calcium hydroxide therefore is a very effective anti-fungal agent against C. albicans.

Viability of human periodontal ligament fibroblasts in tissue culture after exposure to different contact lens solutions.

AIM: The viability of the periodontal ligament (PDL) cells is critical for successful healing of replanted avulsed teeth. Viability is primarily dependent on the duration of the extra-alveolar time and storage medium used to preserve teeth. Several storage media have been suggested but milk ranks highest. It would be desirable to evaluate other media as a suitable alternative for milk. The purpose of this study was to determine the viability of human PDL fibroblasts and their morphology after storage in different types of contact lens solutions. METHODS AND MATERIALS: PDL fibroblasts were cultured from a healthy extracted impacted human tooth and exposed to Bausch and Lomb (Renu), Ciba Vision (Titmus), and Alcon (Opti-free) contact lens solutions. Eagle's minimal essential medium served as control. The experiment was performed in plastic tissue culture clusters containing 24 wells. The PDL fibroblasts were grown in each well for three days. On the day of the experiment the culture medium was decanted, the cells were washed with phosphate buffered saline solution (PBS), and 1 ml of the tested solution was placed in each culture well. All tissue culture clusters were incubated at 37 degrees C in 5% CO2 and 95% air for one, four, and 24 hrs. At the end of the incubation period, the cells were fixed and prepared for scanning electron microscope (SEM) examination. RESULTS: The results indicated Renu and Opti-free solutions were superior to Titmus solution in terms of their capacity to maintain the viability and normal morphology of PDL fibroblasts. CONCLUSION: Contact lens solution is a good storage medium to maintain the viability of PDL fibroblasts for a short-term period.

Microbial leakage of Cavit, IRM, and Temp Bond in post-prepared root canals using two methods of gutta-percha removal: an in vitro study.

The aim of this study was to evaluate the integrity of the coronal seal of Temp-Bond and compare it to Cavit and IRM after post space preparation using S. faecalis as a microbial tracer. In addition, the affect of two methods of gutta percha removal on the apical seal of root canal fillings was also evaluated. Forty extracted human single rooted teeth were prepared chemomechanically and obturated with gutta percha and AH26 sealer cement using the lateral cold condensation technique to a standardized working length of 15 mm. About 10 mm of the coronal gutta-percha was removed with either Peeso-reamer or a hot plugger. The roots were divided into three experimental groups of 10 roots and a control group. Each experimental group was subdivided equally into two groups of 15 each according to the method of post space preparation. Cavit, IRM, and Temp-Bond were used to seal the access opening. Each root was fixed in a cuvette containing Tryptic Soya Broth which, covered 2 mm of the root apex. Bacterial suspension was introduced through pipette. Fresh bacterial suspension was added every week, and the system was monitored daily for the growth of microorganisms for a period of one month. The results showed there was no significant difference in terms of coronal leakage between the three coronal materials used (P=0.478), but the methods of gutta-percha removal did have an impact on the apical leakage (P=0.047). The mean value showed the Peeso-reamer provided less leakage compared to using a hot plugger during the 30-day experimental time period. It was concluded the temporary type of coronal seal of endodontically treated teeth will not prevent coronal leakage if left for a long period of time. In addition, permanent cementation of the post with the coronal restoration should be carried out as soon as possible to prevent recontamination of the root canal.

SEM observations of the attachment of human periodontal ligament fibroblasts to non-demineralized dentin surface in vitro.

PURPOSE: The purpose of this investigation was to study in-vitro the attachment behavior of human periodontal ligament (HPDL) fibroblasts to nondemineralized dentin surface using scanning electron microscope. STUDY DESIGN: Thirty root slices of freshly extracted human teeth of 4 mm thickness as well as six 5x5 mm glass slides used as a control were used in this study. The dentin surface of the root slices was not treated with any chemicals to remove the smear layer. The root slices and the glass slides were placed in tissue culture clusters and an amount of 1 ml of HPDL fibroblast cell suspension was placed over the dentin surface of the root slices and the glass slides. They were then placed into an incubator at 37 degrees C and 100% humidity for 4, 24, and 72 hours. At the end of the incubation, the cells were fixed with glutaraldehyde and examined microscopically. RESULTS: Different shapes of fully spread cells were seen. The cells were attached firmly to the dentin surface by the cytoplasmic extension of the lamellipodia and microvilli which were seen extending inside the opening of the dentinal tubules. CONCLUSION: It was concluded that the human dentin surface provided an excellent surface for attachment of periodontal ligament fibroblasts. In addition, the smear layer did not affect the cell attachment.

Evaluation of antifungal activity of mineral trioxide aggregate.

The purpose of this investigation was to study, in vitro, the antifungal effect of mineral trioxide aggregate (MTA) using a tube-dilution test. MTA was tested freshly mixed and after 24 h set on Candida albicans. The tested MTA was incubated with C. albicans for 1 h, 24 h, and 3 days. Results showed that the freshly mixed MTA was effective in killing the tested fungi after 1 day of contact, whereas the 24-h set MTA was effective after 3 days of incubation. It was concluded that MTA (freshly mixed and 24-h set) was effective against C. albicans.