Prevalence of multiple roots and complex canal morphology in mandibular premolars among a selected Southern Egyptian sub-population: a CBCT-analysis.

The mandibular premolars can pose a significant challenge in root canal treatment due to their complex canal system. This study investigated the prevalence of multiple roots and complex canal morphology of mandibular premolars in a selected Egyptian sub-population using cone beam computed tomography (CBCT). 283 CBCT scans (131 males, 152 females, age 18-70) included 1132 mandibular premolars (566 first, and 566 second premolars) were viewed for incidences ofvariation in root numbers and canal configuration according to Vertucci's classification. CBCT images were assessed by two endodontists, data were statistically analyzed using Fisher exact and Chi-square tests. The majority of first premolars (85.7%) exhibited a single root, whereas 14.7% had 2 roots with a significantly higher frequency in males (19.8%) than in females (9.5%) (P < .05). The most prevalent type was type I (57.8%), followed by type V (21.7%), while types II and VII made up only 1%. Types V and III were more prevalent among females, while males had a higher prevalence of types I and IV. In 2.5% of cases, mandibular second premolars were found to have 2 roots, with a higher incidence in males (P < .05). Type I canals were significantly more prevalent (90.8%) than other types, followed by type V (5.3%) (P < .05). A statistically significant gender correlation was found regarding root number and canal configuration. It is not uncommon to find mandibular first premolars with two roots in the southern Egyptian population, particularly in males. These observations may be valuable for dentists who treat Southern Egyptians, in Egypt and other countries.

Assessment of the canal anatomy of the premolar teeth in a selected Turkish population: a cone-beam computed tomography study.

BACKGROUND: Teeth may have additional roots and a different number of root canals. Overlooked root canals may cause endodontic failure. The aim of this study was to investigate the prevalence of root canals and the number of roots of premolars in a selected Turkish population. MATERIALS AND METHODS: A total of 2,570 teeth from 1,438 patients were evaluated. The cone-beam computed tomography scans of 1,055 maxillary and 1,515 mandibular premolars were examined. RESULTS: Type IV root canal morphology was observed most frequently in maxillary first premolars (77%), and the rates of single and double channel formations were very similar (51% and 49%, respectively). Of the second maxillary premolars, 57.4% had Type I morphology, and 89.9% of the teeth were single-rooted, while 68.6% had a single root canal. The most common formation was Type I (85%) among mandibular first premolars, and a single root was observed in 95.6% of these teeth. In addition, 87% of the mandibular first premolars had a single root canal. The second mandibular premolars mostly had Type I (95.4%) formation, and 99.3% of the teeth were single-rooted, while 96.9% had a single root canal. CONCLUSION: According to our findings, 51% of maxillary first premolars had a single root, 79.4% had two root canals, and 77% had Type IV (77%) formation. Maxillary second premolars mostly had Type I formation. In addition, a single root and single root canal formation were most common. Mandibular first premolars generally had a single root and single root canal formation, but 13% had two root canals, and 6.4% had Type V formation. More than 95% of mandibular second premolars had Type I formation.

Canal configuration and root morphology of mandibular premolars using cone-beam computed tomography in a Korean population.

OBJECTIVES: This study aimed to investigate the anatomy of mandibular premolars from two perspectives-the canal configuration and radicular grooves-using cone-beam computed tomography (CBCT) in a large Korean population. MATERIALS AND METHODS: CBCT images of mandibles acquired from March 2018 to December 2019 for dental treatment were randomly selected. In each image, the root canal of premolars was classified into 8 types according to the canal merging or diverging pattern and the number of apical foramens. The presence and the location of radicular grooves were also assessed. Statistical analysis was performed. RESULTS: A total of 1463 first and 1448 s premolars from 732 patients (390 males, 342 females, mean age of 36.1 years) were evaluated. A single canal with one foramen predominated in both first (85.7%) and second (99.5%) premolars, while complete or partial multi-canals accounted for 14.3% and 0.5% of first and second premolars, respectively. The prevalence of radicular grooves was significantly higher in first premolars (13.2%) than in second premolars (0.5%) and in males (4.3%, n = 119) than in females (2.5%, n = 73). CONCLUSIONS: Although most premolars were complete single canals, the first premolars showed a relatively higher number of complex canals compared to the second premolar. In addition, radicular grooves in mandibular premolars were significantly more common in male patients. CLINICAL RELEVANCE: When planning the endodontic treatment of mandibular premolars, clinicians should be aware of their morphologic complexity, especially in the first premolar of male patients.

A Digital Radiographic Study of Age Estimation Using Area-specific Formula in Odisha Population.

AIM: The aim of the article was to evaluate the feasibility of pulp/tooth area ratio in three mandibular teeth, namely left canine, left first premolar, and left second premolar (33, 34, and 35), as an indicator of age using digital panoramic radiograph and Kvaal's parameters. The study also aimed at computing an area-specific formula for age estimation in Odisha population. MATERIALS AND METHODS: Observation and analysis of 50 digital orthopantomographs (OPGs) and clinical data of patients were made. These images were saved as high-resolution JPEG files. Using the Adobe Photoshop CS3 (extended) image editing software program (Adobe Systems Inc, San Jose, California, United States), the pulp/tooth area ratio of 33, 34, and 35 was analyzed. These ratios were substituted in Odisha population-specific formula, derived using principal component regression analysis. RESULTS: The mean chronological age was 33.24 years. Principal component regression analysis was used to derive multiple regression formulae for individual teeth as well as a combined formula. R2 (coefficient of determination) for combined three mandibular teeth was highest (0.7769) with a standard error of 4.5969 years and thus was a better predictor of age in the population of Odisha. In terms of an individual tooth, comparison between chronological and predicted age revealed that left second mandibular premolar (35) had highest correlation to actual age. Karl Pearson's correlation coefficient showed correlation between age and the mean of ratios from combined three mandibular teeth was stronger than that of single tooth. CONCLUSION: In the present study, second left mandibular premolar showed highest correlation to actual age when used alone. The use of three teeth in combination increased the correlation. This Odisha-specific formula showed promising results and can be used for forensic applications in this population. CLINICAL SIGNIFICANCE: Using three different teeth for age estimation proved to be a better predictor of age in the Odisha population. Moreover, the obtained formula can act as a standard and be used for anthropological or forensic investigations in the said population.

The success of using 2% lidocaine in pain removal during extraction of mandibular premolars: a prospective clinical study.

BACKGROUND: The purpose of this study was to evaluate the anesthetic effectiveness of a buccal infiltration technique combined with local massage (using 2% lidocaine) in the extraction of mandibular premolars to be utilized as an alternative to the conventional inferior alveolar nerve block. METHODS: Patients eligible included any subject with a clinical indication for tooth extraction of the mandibular 1st or 2nd premolars. All patients were anesthetized buccally by local infiltration technique followed by an external pressure applied for 1 min directly over the injection area. In each case, another local injection was given lingually. All operations were started at approximately 5 min after the buccal injection. The collected data included age, gender, pain perception and its intensity during treatment at three checkpoints, apical tenderness, and the type of extraction. Any associated complications or difficulties were also recorded. Then the results were analyzed and interpreted using appropriate statistical tests. The significance level was set at P ≤ 0.05. RESULTS: A total of 247 cases (1st premolar, n = 119; 2nd premolar, n = 128), predominantly male, were included. In 95% of study sample, the patients were satisfied with the dental extraction without any pain. However, in 5% of cases, pain was reported at the stage of tooth removal. Apical tenderness was found to be present in 11% of the total cases. Three teeth required surgical removal. Upon analysis, no significant differences in the success rates were detected between the 2 premolar groups or amongst the various age groups. Minor and transient side effects were reported in this study. CONCLUSION: The technique is simple and effective as well. It might be considered as an alternative anesthetic injection to the inferior alveolar nerve block for dental extraction of the mandibular premolars.

C-shaped canal configuration in mandibular premolars and molars: Prevalence, correlation, and differences: An In Vivo study using cone-beam computed tomography.

AIMS: To evaluate the prevalence, correlation, and differences of C-shaped canal morphology in mandibular premolars and molars by means of cone-beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 1433 mandibular premolars and molars CBCT scans from the Saudi population were evaluated. Axial sections of the roots were acquired at coronal, middle, and apical levels to evaluate C-shaped canals types. The prevalence, correlation, differences of C-shaped canals, bilateral/unilateral presence, gender differences, and location of external grooves on roots were assessed. RESULTS: The prevalence of C-shaped canals in the first premolars was 1.5%, 0.80% in second premolars and 7.9% in second molars, whereas C-shaped canals were absent in first molars. No correlation was found between the presence of C-shaped canals within premolars and molars and between the two groups in the same individual. Both premolars and molars exhibited different types of C-shaped canals, C2 being predominant in premolars and C3 in second molars. Longitudinal external grooves were mostly located on mesiolingual (ML) surface in premolars and lingual in molars. Females showed more prevalence of C-shaped canals in second molars and no differences in premolars. Bilateral symmetry and unilateral presence in premolars and second molars were not significant. CONCLUSIONS: Although the prevalence of C-shaped canals is significantly higher in mandibular second molars, they are also found in mandibular premolars but in small percentages. No significant differences were found between both genders and both sides. Since they exhibit unpredictable morphology and differences across the root length, the use of small field CBCT is recommended when such anatomy is presented in a tooth indicated for root canal treatment for better management.

Frequency of non-single canals in mandibular premolars and correlations with other anatomical variants: an in vivo cone beam computed tomography study.

BACKGROUND: A knowledge regarding anatomical variants is important to achieve success in endodontic treatment. Root canal treatment of mandibular first premolars (PM1 s) is challenging due to the existence of numerous variations in canal configurations, including a C-shaped variant. We aim to determine the frequency and morphologic characteristics of non-single canals of mandibular first (PM1 s) and second (PM2 s) premolars in a Korean population using cone beam computed tomography (CBCT) and to evaluate correlations between non-single canals of PM1 s and other anatomical variants, such as distolingual roots (DLRs) in mandibular first molars (M1 s) and C-shaped canals in mandibular second molars (M2 s). METHODS: A total of 971 PM1 s and 997 PM2 s from 500 patients were examined in vivo by CBCT. Root canal configurations and C-shaped canals were determined in accordance with the Vertucci classification and Fan classification, respectively. The correlation between non-single canals in PM1 s and DLRs in M1 s was evaluated using logistic regression analysis. RESULTS: PM2 s typically had one root (99.89%) with one canal (98.4%). Among PM1 s with non-single canals (21.2%), Vertucci type V (10.9%) and C-shaped (3.7%) canals were prevalent. Among C-shaped PM1 canals, the majority were Vertucci type V (77.8%); a C-shaped configuration (C2) was predominant mostly at the middle and/or apical third of the root. After adjusting for other variables (i.e., sex, age, and side), C-shaped canals in PM1 s was significantly correlated with the presence of DLRs in M1 s (odds ratio = 2.616; 95% confidence interval, 1.257-5.443; p = 0.010). CONCLUSIONS: The presence of C-shaped PM1 canals was positively related to the presence of DLRs in M1 s. Although C-shaped canals in PM1 s are difficult to distinguish, this finding could aid clinicians in predicting C-shaped canal configurations in PM1 s of patients who exhibit DLRs in M1 s.

Cone-beam Computed Tomographic Analysis of C-shaped Canals and Radicular Grooves in Mandibular Premolars: Prevalence and Related Factors.

AIM: This study aimed to evaluate the prevalence of C-shaped canals and radicular grooves (RGs) in mandibular premolars using cone-beam computed tomography (CBCT) and correlating it with other factors like age, sex, unilateral, and bilateral prevalence. MATERIALS AND METHODS: CBCT images of 242 patients with an age group of 13-70 years were selected from pre-existing database. The prevalence of C-shaped canal and RG was recorded along with variables such as age, sex, and bilateral prevalence. STATISTICAL ANALYSIS: Prevalence was compared using the Chi-square test (p < 0.05). RESULTS: The prevalence of C-shaped configurations in the mandibular first premolars (17.4%) was significantly higher (p < 0.05) as compared with the mandibular second premolars (7.4%). CBCT analysis revealed that in cervical third, 88% of canals were found to be C4 type. A high prevalence of C2 type canal was found in middle (68.6%) and apical third (31.3%). The prevalence of RG in the mandibular first premolars (13%) was significantly higher (p < 0.05) as compared with the mandibular second premolars (4.3%). There was no statistically significant difference between sex and prevalence of C-shaped canals and RG but it was significantly higher in the age group of <50 years (p < 0.05). CONCLUSION: This study showed a high prevalence of C-shaped canals and RG in mandibular first premolars as compared with mandibular second premolars. The prevalence of the C-shaped canal and RG was significantly higher in the age group of <50 years. This knowledge may aid the clinicians for good endodontic prognosis. CLINICAL SIGNIFICANCE: This study result provides valuable insight into the prevalence of C-shaped canal and RG among the premolars which can help clinicians to prevent perforations or root fractures. How to cite this article: Srivastava S, Gaikwad RN, Alsalhi N, et al. Cone-beam Computed Tomographic Analysis of C-shaped Canals and Radicular Grooves in Mandibular Premolars: Prevalence and Related Factors. J Contemp Dent Pract 2019;20(11):1350-1354.

Micro-CT evaluation of C-shaped mandibular first premolars in a Brazilian subpopulation.

AIM: To describe morphometric aspects of the internal anatomy of C-shaped mandibular premolars from a Brazilian subpopulation using micro-CT analysis. METHODOLOGY: First mandibular premolars with radicular grooves (n = 123) were scanned using a micro-computed tomography system. After cross-section analysis, 83 specimens were identified with a C-shaped canal and selected for micro-CT analysis. Number and location of canals according to Vertucci's classification, distances between anatomic landmarks, occurrence of apical deltas, furcation canals, prevalence of C-shaped cross-sections at five levels as well as 2-dimensional analysis (Area, perimeter, roundness, aspect ratio, major and minor diameters) were performed for the more prevalent anatomical features. Data were compared statistically using Kruskal-Wallis tests (α = 0.05). RESULTS: The more prevalent anatomical types according to Vertucci's classification were Type I (13%), III (8%), V (37%) and VII (2%). Mean distances from the furcation to the cemento-enamel junction were in the range of 5.36-5.65 mm. Apical deltas and furcation canals were present in 36 (43%) and 27 (33%) specimens, respectively. C-shaped cross-sections were more prevalent at the middle (56%) and apical middle levels (81%). Overall, significant differences were found in the 2-dimensional analyses between single canals at the apical third and buccal and lingual canals of Vertucci's V classification (P < 0.05). CONCLUSIONS: In this Brazilian subpopulation, C-shaped canal configuration of the root canal system was found in 67% of extracted first mandibular premolars with radicular grooves. Vertucci's types I and V were the most prevalent anatomical variations. C-shaped cross-sections were more prevalent in the middle third, and the presence of apical deltas was the most common feature in the apical third.

A cone-beam computed tomography study of root canal morphology of maxillary and mandibular premolars in a Turkish population.

AIM: The aim of this study was to evaluate the root canal number and configuration of maxillary and mandibular premolar teeth by gender, intervals for decades, tooth position and unilateral or bilateral occurrence in a Turkish population using Cone Beam Computed Tomography(CBCT) scanning. METHODOLOGY: CBCT images of 5496 maxillary and mandibular premolars from 849 patients were evaluated. The following was evaluated in all the images: numbers of roots and root canals, the morphology of the root canal configuration according to the Vertucci classification, male-female differences in the tooth position and male-female differences in unilateral or bilateral occurrence. The reliability data were analyzed with a chi-square test. RESULTS: The most prevalent root canal frequency was the two canals (86.2%) and type IV (76.9%) configuration for maxillary first premolar, one canal (59.7%) and type I (54.5%) canal configuration for second premolar. The incidence of one canal was higher in females and the occurrence of two or three canals was more common in males. The incidence of one canal was higher on the left side of maxillary premolars and the incidence of two canals was higher on the right side. Most mandibular first (93.5%) and second (98.5%) premolars had one canal. In general, females had one root canal of the mandibular premolar, whereas males had two or three canals. The type I configuration was most common and the incidence was higher on the right side. There were some differences found in the frequency distribution of the number of root canals and configuration of maxillary and mandibular premolar teeth according to intervals for decades. CONCLUSION: CBCT scanning provides comprehensive information about the root canal morphology of maxillary and mandibular premolar teeth. These data may help clinicians in root canal treatment of premolar teeth.

Mental foramen and apical foramen: A dangerous anatomical proximity.

The study evaluated the spatial position of the mental foramen (MF) using 300 cone-beam computed tomography. The spatial position was analyzed with the horizontal location and relative location (distance between apical foramen and MF). The horizontal location was assessed through three positions (positions 1, 2, and 3). The relative location was determined with the x, y, and x coordinates of the root apex of mandibular premolars and the MF. Student's t-test and chi-square were performed. The most common horizontal location (52%) was position 2, which means between the premolars (p < 0.05). The relative location of the MF to the root apex of the second premolar was closer than the first premolar (p < 0.05). The distance between the root tip of the second premolar and the MF was 5.27 mm, with a minimum value of 1.87 mm. Clinicians should be aware of the possible neural results to the mental nerve of an endodontic infection and the extrusion of irrigation solutions.

The Stresses and Deformations in the Abfraction Lesions of the Lower Premolars Studied by the Finite Element Analyses: Case Report and Review of Literature.

BACKGROUND: The purpose of the study was to investigate the behavior of hard dental structures of the teeth with abfraction lesions when experimental occlusal loads were applied. METHODS: A 65-year-old patient came to the dentist because she had painful sensitivity in the temporomandibular joints and the lower right premolars. The patient was examined, and cone-beam computed tomography (CBCT) of the orofacial area was indicated. The data provided from the CBCT were processed with Mimics Innovation Suite 17 software to create the desired anatomical area in 3D format. Then, the structural calculation module was used in order to perform a finite element analysis of the lower right premolar teeth. A focused review of articles published between 2014 and 2023 from specialty literature regarding the FEA of premolars with abfraction lesions was also conducted. RESULTS: The parcel area and the cervical third of the analyzed premolars proved to be the most vulnerable areas under the inclined direction of occlusal loads. The inclined application of experimental loads induced 3-4 times higher maximum shears, stresses, and deformations than the axial application of the same forces. CONCLUSIONS: FEA can be used to identify structural deficiencies in teeth with abfractions, a fact that is particularly important during dental treatments to correct occlusal imbalances.

Optimizing Root Canal Therapy: An In Vitro Comparative Study of Innovative File Systems on Mandibular Premolar Fracture Resistance.

INTRODUCTION AND AIM:  Root canal therapy is a vital procedure for saving teeth by removing infection and cleaning the complex root canal system. However, a delicate balance exists between thorough cleaning and preserving tooth strength. The study aims to evaluate the instrumentation effect of three innovative file systems, XP-endo® shaper, Reciproc®, and Self-adjusting file (SAF) on fracture resistance of mandibular premolars. MATERIALS AND METHODS: Thirty single-rooted mandibular premolars were collected; a standard access cavity was prepared and the working length was established 1 mm short of the apex. The teeth were randomly divided into three groups(n=10). In Group 1, the shaping of the specimens was achieved using XP-endo® shaper; in Group 2, it was instrumented using Reciproc® file; and in Group 3, it was instrumented using SAF. All samples were decoronated and the roots were mounted vertically in acrylic resin and subjected to fracture resistance under a universal testing machine. RESULTS: Intergroup analysis was done by one-way ANOVA followed by Bonferroni post hoc test, which did not report a statistically significant difference (p>0.05). CONCLUSION: All three tested file systems were similar in fracture resistance. XP-endo® shaper exhibited better fracture resistance on root canal instrumentation when compared to Reciproc® and SAF although they are not statistically significant.

Morphology of the Physiological Foramen: II. Maxillary and Mandibular Premolars.

INTRODUCTION: Information concerning the anatomy of the physiological foramen is still limited. The aim of this study was to investigate the distance between the physiological and anatomic apex, the shape and diameter of the physiological foramen in maxillary (Mx) and mandibular premolars (Mn). METHODS: The anatomy of the apex of 229 maxillary (first: MxP1; second: MxP2) and 221 mandibular premolars (first: MnP1; second: MnP2) from a mixed Swiss-German population was investigated by means of microcomputed tomography and 3-dimensional software imaging. RESULTS: The following results were obtained in the presence of a main physiological foramen. 1. The distance between the physiological and anatomic foramen was 0.29-0.99 mm (MxP1), 0.21-1.03 mm (MxP2), 0.13-0.8 (MnP1), and 0.15-1.41 (MnP2). 2. The mean narrow and wide diameters of the physiological foramen were 0.19-0.33 mm (MxP1), 0.25-0.42 mm (MxP2), 0.28-0.37 (MnP1), and 0.28-0.40 (MnP2). 3. The most common physiological foramen shape was oval (66.7% MxP1, 89.7% MxP2, 91.8% MnP1, 64.4% MnP2). CONCLUSION: Considering the recommended preparation sizes based on a size corresponding to the friction, that is at the narrowest point in the area of the apical constriction (physiological foramen), and within the limitations of this ex vivo microcomputed tomography study, a final preparation size could be chosen when considering the pertaining morphologic considerations; yet, to a minimum ISO 30 size.

Endodontic management of aberrant canal morphology in mandibular premolar: A case series.

A thorough assessment of complex canals in any tooth is a crucial prerequisite for the success of the treatment. The radicular space is often complex, and the canals might also additionally separate at all levels of the root canals, which poses a great challenge to the treating clinician. The mandibular premolars often have variations and complexity in the canal system. The abnormal morphology of these mandibular premolars makes it inaccessible to find and negotiate the additional canals; failure to identify other canals often leads to unsuccessful root canal treatment. This case series reports five successful nonsurgical root canal treatments in mandibular premolars.

Posttreatment stability following therapy using passive self-ligating brackets: extraction vs. nonextraction.

PURPOSE: This study aimed to evaluate the effects of lower premolar extraction on posttreatment stability one year following fixed orthodontic treatment with passive self-ligating brackets (Damon system, Ormco, Orange, CA, USA). METHODS: All patients were treated with fixed orthodontic appliances using passive self-ligating brackets (Damon). For retention, removable Hawley retainers were used. Two groups of patients were included in the study. Each group consisted of 23 patients: group Ex consisted of 10 male and 13 female patients (13.4 ± 1.6 years old) with extraction of lower first premolars and group NonEx consisted of 11 male and 12 female patients (13.4 ± 3.9 years old) without dental extractions. The patients' dental models and photographs were assessed at T0 (pretreatment), T1 (the end of active orthodontic treatment: 3.3 ± 1.0 years in the Ex and 2.3 ± 0.8 years in the NonEx group) and at T2 (1 year posttreatment). All lower casts were scanned and the following dental parameters were recorded and compared between the two groups: intercanine width (ICW), anterior arch width (AAW), intermolar width (IMW), Little's irregularity index (LII) and gingival recessions. RESULTS: An increase in ICW (group Ex: 1.20 ± 2.51 mm and group NonEx: 0.84 ± 1.48 mm) by the end of active treatment (T1; P < 0.05), as well as a relapse regarding the ICW (group Ex: -0.1 ± 0.47 mm and group NonEx: -67% ± 0.38 mm) one year post-treatment (T2) were recorded in the samples. Relapse in the non-extraction group was statistically and clinically significant, whereas ICW values remained relatively stable in the extraction group during the posttreatment period (T1-T2). The irregularity index decreased during treatment (group Ex: -8.79 ± 6.36 mm and group NonEx: -5.24 ± 2.99 mm) and relapsed in both groups (group Ex: 0.57 ± 90 mm and group NonEx: 0.27 ± 0.53). The rate of relapse in LII was correlated to the relapse rate of ICW. A reduction of IMW was recorded in the Ex group (-1.89 ± 1.82 mm) during active treatment (P < 0.05), which remained stable 1 year posttreatment. AAW increased in both groups (group Ex: 2.77 ± 1.77 mm and group NonEx: 1.77 ± 2.04 mm) throughout active treatment and remained stable at T2. CONCLUSION: Intergroup comparison revealed that ICW remained stable 1 year posttreatment in the Ex group, whereas high relapse of ICW was recorded in the NonEx group. Furthermore, risk of a relapse of LII appears to be higher in cases with a relapse of the ICW.

Prevalence of Second Root and Root Canal in Mandibular and Maxillary Premolars Based on Two Classification Systems in Sub-Population of Northern Region (Saudi Arabia) Assessed Using Cone Beam Computed Tomography (CBCT): A Retrospective Study.

The objective of this paper is to assess the prevalence of a second canal in maxillary and mandibular premolars based on two classification systems of root canal morphology using Cone beam computed tomography (CBCT) images. A total of 286 CBCT scans from the archive of the Radiology department of a hospital were assessed for the presence of a second canal in maxillary and mandibular premolars. The canal configuration and its assessment was undertaken using Vertucci and Ahmed's classification. A Chi-square test was used to test the significance of the difference between gender and age. A total of 286 premolars were examined (217 mandibular premolars and 69 maxillary premolars); of these, 173 teeth (60.5%) were from males and 113 were from females (39.5%). Some 62% of maxillary left first premolars had two roots, followed by maxillary right first premolars (47%), and then maxillary left second premolars (30%) and maxillary right ones (27%), respectively. Type IV Vertucci were seen in maxillary premolars, while type I were ordinarily seen in the included mandibular premolars. Surprisingly, Vertucci type III was only found in mandibular left first premolars at a frequency of 2%. One orifice with two separate canals and two orifices of two distinct canals with two portals of exit were predominantly noticed with maxillary first premolars (2 FP B1 P1) in 73% and 81%, respectively, followed by (1 FP 2) 19%. The prevalence of a second canal in maxillary and mandibular premolars was low in the investigated premolars in comparison to the premolars that had just one root and canal, as assessed based on Vertucci and Ahmed's root canal system classification.

Root Canal Morphology of Premolars in Saudis.

AIM: This study aimed to evaluate root number and morphological variations of the root canal system in maxillary and mandibular premolars among the Saudi subpopulation. METHODOLOGY: A total of 500 cone-beam computed tomography (CBCT) images were assessed, including 2442 maxillary and mandibular premolars. The evaluation encompassed the number of roots and canals and their configuration based on the Vertucci classification. Gender differences were considered, along with the position of premolars and unilateral or bilateral symmetry. RESULTS: Maxillary first premolars predominantly exhibited two roots (82.6%), followed by one root (16.3%) and three roots (0.97%), with a majority having two root canals (83.6%). Regarding maxillary second premolars, the most common morphology was one root (66.6%), with two root canals (40.5%) observed more frequently than one root canal (38.1%). Mandibular first and second premolars mainly featured one root (84.8% and 96.1%, respectively) with one root canal (70.8% and 90.2%, respectively), whereas two root canals were less prevalent (2.3% and 1.8%, respectively). Three canals and three roots were rarely found in mandibular premolars (0.3%). Regarding maxillary premolars, males exhibited significantly higher type IV and mandibular type I root configurations compared with females. Conversely, regarding mandibular premolars, females showed significant mandibular type V and higher type I root configurations compared with males. CONCLUSION: CBCT imaging facilitated precise assessment of root morphology and root canal configurations in maxillary and mandibular premolars. The present findings can aid dentists in diagnosing, evaluating case difficulty, and devising effective root canal treatments, particularly in patients from Saudi Arabia.

Surgical-anatomical evaluation of mandibular premolars by CBCT among the Italian population.

BACKGROUND: The thorough knowledge of the anatomy of mandibular premolars is an essential factor for a correct approach to endodontic treatment, concerning both non-surgical and surgical treatment. OBJECTIVES: Since there is no data on the Italian population in this context, the aim of this study was to evaluate, from a surgical perspective, the anatomy of mandibular premolars among the Italian population through a cone-beam computed tomography (CBCT) analysis, considering the morphology of their root canals according to Vertucci's classification and the prospect of their apices with regard to the vestibular bone plate and the proximity to the inferior alveolar nerve and the mental foramen as well as to evaluate the most appropriate distance from the apex in the radicular resection (3 mm or 5 mm). MATERIAL AND METHODS: At total of 492 CBCT acquisitions (from 246 males and 246 females) were included retrospectively, evaluating 720 mandibular premolars. Age, gender, the tooth position in relation to the vestibular plate, the number of roots, the tooth length and the root length, the number of canals, the configuration of the root canal system according to Vertucci's criteria, C-shaped canals, the distance from the cementoenamel junction (CEJ) to the canal bifurcation, the number of apical foramina, and the distance from the apex to the inferior alveolar nerve or the mental foramen were evaluated. RESULTS: The study highlighted the frequent anatomic variability of the root canal system. It found the presence of 1 root for first and second premolars in 97% and 99% of cases, of 2 roots in 2.7% and 0.7% of cases, and of 3 roots in 0.3% and 0.3% cases, respectively. In 92% of cases, the mental foramen was located below a second premolar, or between a first premolar and a second premolar; only in 8% of cases, it was located close to a first premolar, but never as close as to a second premolar. CONCLUSIONS: Mandibular premolars show a truly surprising anatomical variability, especially for mandibular first premolars, which therefore requires adequate radiographic planning before providing any endodontic treatment, or especially endodontic retreatment or endodontic surgery. Taking into account proximity to the inferior alveolar nerve and the mental foramen, any surgical approach must be carefully planned. Frequently, a two-dimensional (2D) radiographic examination is not sufficient to fully understand the anatomical variability of these teeth.

The Effect of Bioceramic HiFlow and EndoSequence Bioceramic Sealers on Increasing the Fracture Resistance of Endodontically Treated Teeth: An In Vitro Study.

Background/purpose Root fractures after endodontic treatment are a serious complication, and it often causes tooth loss, several studies have found a correlation between root canal preparation and filling, and the possibility of root fracture. Therefore, this study aimed to evaluate the root fracture resistance of the endodontically treated mandibular premolars after preparing and filling by EndoSequence Bioceramic (BC), EndoSequence BC HiFlow, and AH Plus (AHP). Materials and methods The study sample consisted of 75 single-rooted and single-canal mandibular premolars, they were randomly distributed into five groups: Group I: root canals preparation and fillings with AHP sealer; Group II: root canals preparation and fillings with EndoSequence BC sealer; Group III: root canals preparation and fillings with BC HiFlow sealer; Group IV (Negative Control): without root canals preparation; and Group V (Positive Control): canals preparation without root canals filling. A glide path was established by #10 hand K-file, then the crowns were cut, and the canals were prepared and filled. All teeth were restored with glass ionomer cement and kept in an incubator at 37°C for a week. All samples were placed within acrylic bases and a vertical force was applied using a Testometric machine and the fracture resistance force was recorded. Results EndoSequence BC and BC HiFlow groups showed slightly better fracture resistance (494.440, 496.960 N respectively) than AHP group (492.680 N). However, no statistically significant difference was found between the two groups (P-value >0.05). The greatest mean fracture force was observed in the positive control group (736.040 N) with statistically significant difference between the other groups (P-value <0.01) and the least mean fracture force was shown in the negative control group (318.040 N) with statistically significant difference between the other groups (P-value <0.01). Conclusion Based on this in vitro study, the use of EndoSequence BC, BC HiFlow, and AHP enhanced the fracture resistance in root-filled single-rooted premolar teeth. While, the application of EndoSequence BC, BC HiFlow, and AHP did not increase the fracture resistance of roots compared to that of unprepared root canals.