Root Canal Orifices Research Articles

A study of the distobuccal root canal orifice of the maxillary second molars in Chinese individuals evaluated by cone-beam computed tomography

As is commonly understood, the root canal morphology of the maxillary molars is usually complex and variable. It is sometimes difficult to detect the distobuccal root canal orifice of a maxillary second molar with root canal treatment. No literature related to the distobuccal root canals of the maxillary second molars has been published.ObjectiveTo investigate the position of the distobuccal root canal orifice of the maxillary second molars in a Chinese population using cone-beam computed tomography (CBCT). Material and methodsIn total, 816 maxillary second molars from 408 patients were selected from a Chinese population and scanned using CBCT. The following information was recorded: (1) the number of root canals per tooth, (2) the distance between the mesiobuccal and distobuccal root canal orifice (DM), (3) the distance between the palatal and distobuccal root canal orifice (DP), (4) the angle formed by the mesiobuccal, distobuccal and palatal root canal orifices (∠ PDM). DM, DP and ∠ PDM of the teeth with three or four root canals were analyzed and evaluated. ResultsIn total, 763 (93.51%) of 816 maxillary second molars had three or four root canals. The distance between the mesiobuccal and distobuccal orifice was 0.7 to 4.8 mm. 621 (81.39%) of 763 teeth were distributed within 1.5-3.0 mm. The distance between the palatal and distobuccal orifice ranged from 0.8 mm to 6.7 mm; 585 (76.67%) and were distributed within 3.0-5.0 mm. The angle (∠ PDM) ranged from 69. 4º to 174.7º in 708 samples (92.80%), the angle ranged from 90º to 140º. ConclusionsThe position of the distobuccal root canal orifice of the maxillary second molars with 3 or 4 root canals in a Chinese population was complex and variable. Clinicians should have a thorough knowledge of the anatomy of the maxillary second molars.

Microcomputed tomography analysis of mesiobuccal orifices and major apical foramen in first maxillary molars.

Objective:Aim of the study was to determined by microcomputed tomography (µCT) the horizontal distance between the main (MB1) and the second mesiobuccal canal (MB2) orifices, the vertical distance between the MB1 and MB2 orifices planes, and the distance between the anatomic apex and major apical foramen (AF). Furthermore, we characterized the entire internal and external anatomy of the MB, distalbuccal (DB) and palatal (P) maxillary first molars roots.Materials and Methods: Twenty-two intact extracted first maxillary molars were scanned by X-ray computed transaxial µCT and then 2D and 3D images were processed and analyzed.Results:The results showed that 77.27% of the mesiobuccal (MB) roots presented a second MB canal, and 29.41% of the MB2 were independent from the MB1 canals. In 15 teeth, there were three root canal orifices on the chamber floor, and 10 of these teeth presented MB2 canals. The mean vertical distance between the MB1 and MB2 planes was 1.68 ± 0.83 mm. Seven teeth had four orifices. The mean horizontal interorificial distance between the MB1 and MB2 orifices was 1.21 ± 0.5 mm. Accessory canals were observed in 33.33% of the roots, loops in 6.06%, while isthmuses were found in 15 of the 22 MB roots. Of the total roots, 74.24% presented one foramen, while all of the roots showed a major apical foramen that was not coincident with the anatomic apex. Conclusions:Our µCT analysis provided interesting features on the horizontal and vertical distance between the MB1 and MB2 orifices and on the distance of AF and anatomic apex.Clinical Relevance:These results have an important clinical value because might support the endodontist in the recruitment, negotiation and obturation of maxillary first molar canal system.

A micro-computed tomography study of the root canal morphology of the mandibular first premolar in a population from southwestern China

This study aimed to investigate the root canal morphology of mandibular first premolar teeth in a population from southwestern China by micro-computed tomography (micro-CT). Human mandibular first premolars (115) were selected and prepared for micro-CT analysis with a slice thickness of 30 μm. Details of root canal orifices, canals, accessory canals, apical foramina-apical delta intercanal communication, loops and isthmuses, and mesial invagination were analyzed from reconstructed three-dimensional (3D) images. Canal patterns categorized according to the classification defined by Vertucci (Endod Top 10:3-29, 2005) as types I (65.2%), III (2.6%), V (22.6%), and VII were identified (0.9%). Accessory canals were present in 35.7% of the samples and were predominantly located in the apical third of the root. A single apical foramen was observed in 50.4% of the samples and two or three foramina in 28.7% and 14.8%, respectively. Apical delta was identified in 6.1% of the samples and the prevalence of intercanal communication and loops was 3.5% and 7%, respectively. Mesial invagination of the root was identified in 27.8% of the samples, the majority of which contained multiple canals. The data obtained in this study revealed complex root morphology with high prevalence of multiple canals, more than half of which exhibited type I canal patterns. Micro-CT was used as a noninvasive technique for 3D investigation of root canal morphology in the mandibular first premolars of a population from southwestern China. Furthermore, data obtained revealed complex anatomy of various types.

An optimized video system for augmented reality in endodontics: a feasibility study

We propose an augmented reality system for the reliable detection of root canals in video sequences based on a k-nearest neighbor color classification and introduce a simple geometric criterion for teeth. The new software was implemented using C++, Qt, and the image processing library OpenCV. Teeth are detected in video images to restrict the segmentation of the root canal orifices by using a k-nearest neighbor algorithm. The location of the root canal orifices were determined using Euclidean distance-based image segmentation. A set of 126 human teeth with known and verified locations of the root canal orifices was used for evaluation. The software detects root canals orifices for automatic classification of the teeth in video images and stores location and size of the found structures. Overall 287 of 305 root canals were correctly detected. The overall sensitivity was about 94 %. Classification accuracy for molars ranged from 65.0 to 81.2 % and from 85.7 to 96.7 % for premolars. The realized software shows that observations made in anatomical studies can be exploited to automate real-time detection of root canal orifices and tooth classification with a software system. Automatic storage of location, size, and orientation of the found structures with this software can be used for future anatomical studies. Thus, statistical tables with canal locations will be derived, which can improve anatomical knowledge of the teeth to alleviate root canal detection in the future. For this purpose the software is freely available at: http://www.dental-imaging.zahnmedizin.uni-mainz.de/.

Endodontic management of mandibular central incisor fused to a supernumerary tooth associated with a talon cusp: a case report

To report the successful non-surgical endodontic management of a mandibular central incisor fused to a supernumerary tooth associated with a talon cusp. Fusion and gemination are developmental anomalies of teeth that may require endodontic treatment. In this article, a case of successful endodontic management of a permanent mandibular right central incisor fused to its supernumerary counterpart associated with a talon cusp is reported. The incidence of fusion in mandibular anteriors is rare. A search of the literature failed to reveal any reports on the fusion of a permanent mandibular central incisor with its supernumerary counterpart associated with a talon cusp. Successful non-surgical endodontic management of a case is reported. • Fused and geminated teeth requiring endodontic treatment present diagnostic and technical challenges. • An exact differentiation between fusion and gemination may not be critically important for treatment. • The use of an operating microscope for detection of additional root canal orifices in complicated cases is recommended.

Do the Positions of the Mesial Root Canal Orifices on the Pulp Chamber Floor Matter in Mandibular Molars?

Do the Positions of the Mesial Root Canal Orifices on the Pulp Chamber Floor Matter in Mandibular Molars?

Intraoral Cameras as a Computer‐Aided Diagnosis Tool for Root Canal Orifices

The aim of this study was to evaluate the diagnostic advantage of a new software tool in combination with an intraoral camera for automatic detection of root canal orifices in life videos via the access cavity of extracted human molars. The performance of a predoctoral dental student analyzing the images of the camera (without automatic detection) was compared with that of an experienced observer. Sensitivity and confidence intervals were provided and compared with histological slices of 200 teeth used for evaluation. The software's sensitivity for detection of root canal orifices was 0.957 (95 percent confidence interval: 0.936 to 0.972). The sensitivity for the observer was 0.906 (95 percent confidence interval: 0.877 to 0.929) compared to 0.847 (95 percent confidence interval: 0.813 to 0.877) achieved by the predoctoral student. The tested software reaches a high sensitivity for automatic real-time detection of root canal orifices with intraoral cameras in direct comparison to histological images. The system might be a useful help for both pre-and postdoctoral students as an aid for the detection of second mesiobuccal root canal orifices.

Recognition of root canal orifices at a distance – a preliminary study of teledentistry

The remote recognition of root canal orifices was tested on 50 images of endodontically accessed teeth acquired with an intra-oral camera. The images were stored on a laptop computer and were presented to 20 observers who marked the visible canal orifices using software which stored the canal locations in standard files. The marked positions were verified on histological slices. In 87% of the cases, the canal locations were marked correctly. Inter-observer reliability depended on the location of the reviewed root canal (kappa = 0.44-0.77). The detection rate was related to the professional experience of the observers. The maximum proportion of accurate detections was found for the observers with more than 10 years of professional experience. The minimum proportion of accurate detections, 79%, was by the observer with one year of experience. The results of the study suggest that remote recognition of root canals by experienced dentists can help younger colleagues in the detection of root canal orifices.

Localization of root canal orifices in mandibular second molars in relation to occlusal dimension

To evaluate the localization and distribution of canal orifices of mandibular second molar teeth in relation to the mesio-distal and bucco-lingual dimensions of coronal tissue. Fifty extracted mandibular second molar teeth were embedded into plaster blocks with their vertical axes aligned perpendicular to the horizontal plane. The teeth were photographed digitally from the occlusal aspect under 12 x magnification. Thereafter, the occlusal halves of crowns were sectioned off to expose the root canal orifices. The teeth were than photographed under the same magnification, after which the pre- and post-sectioning images of each specimen were stacked into a single file. To plot the coordinate of each canal orifice, a 0.5-mm grid analytical plane was mounted digitally on the stack so that the x- and y-axes of the plane were superimposed on the mesiodistal and buccolingual axes (bisectors) of the tooth crowns. Localization and distribution of the coordinates of the canal orifices were evaluated using the chi-square test (P = 0.05). Only one tooth displayed a single root canal orifice, located in the mesiobuccal-distolingual 'centre' of the occlusal surface. The majority of mandibular second molars had three orifices (72%), followed by those with two (16%) and four (10%). The distal canal was located lingual to the centre of the occlusal plane. The distal canal was located lingual to the centre of the occlusal plane of mandibular second molars. The possibility of observing more divergent localizations and orifice numbers should not be overlooked in clinical practice.

Recognition of Root Canal Orifices in Video Sequences as a Future Support System During Endodontic Treatment

IntroductionThe objective of this study was to show the practical application of computer-aided techniques for detecting root canal orifices through the access cavity using a video camera mounted on a microscope. MethodsA minimum distance classification image recognition algorithm was tested in an in vitro study to assess the possibilities of computer-aided recognition of root canal orifices. A Motic DM143 digital stereo microscope (Motic Germany GmbH, Wetzlar, Germany) was used because it includes a video camera that can be connected via USB1.1 to any computer. ResultsThe newly developed software is capable of communicating with a video camera and can automatically detect the root canal orifices in all teeth used in this study. A total of 165 extracted human teeth (molars and premolars) were used as test data to collect 8,250 images via screenshots for the evaluation of the detection quality. The software provided a detection sensitivity of 90.1%, with only 11.9% of the images as false-positive detections. ConclusionThe study shows that computer-aided recognition of root canal orifices with video cameras is possible.

The Ability of Portland Cement, MTA, and MTA Bio to Prevent Through-and-Through Fluid Movement in Repaired Furcal Perforations

This study assessed the ability of Portland cement, white Angelus-mineral trioxide aggregate (MTA), and MTA Bio to seal furcal perforations in extracted human molar teeth. Fifty-five human mandibular molar teeth were accessed, and the canal orifices were located. The roots were horizontally sectioned in the middle third. Resin composite was used to fill the root canal orifices and the apical end of the root. Perforations were created in the center of the pulp chamber floor by using a size 3 round bur. The teeth were divided into 3 groups (n = 15), and an additional 10 teeth served as controls. In G1, the perforation defects were repaired with MTA, whereas in G2 and G3, MTA Bio and Portland cement were used, respectively. Each tooth was assembled in a hermetic cell to allow the evaluation of fluid filtration. Leakage was measured by the movement of an air bubble traveling within a pipette connected to the teeth. Measurements of the air bubble movement were made after 10 minutes at a constant pressure of 20 cm H(2)O. Kruskal-Wallis H test was applied to the fluid flow data to detect differences between the experimental groups (P < .05). Leakage existed in every sample and was very variable in all the experimental groups, ranging from 0.098-0.51 microL/min. Kruskal-Wallis H-test results showed that there was no significant difference in mean fluid flow between the experimental groups (P = .874). The sealing ability promoted by the 3 cements was similar; no cement was able to produce a fluid-tight seal.

Four canals in the mesial root of a mandibular first molar. A case report under the operating microscope

In this era of microscope-assisted endodontics, finding variations in root canal system anatomy is not uncommon. Operating microscopes combined with careful clinical examination and radiographic interpretation can aid the clinician to successfully treat cases with such internal anatomy. The understanding of this view enables the possible location of additional canals in any tooth requiring endodontic treatment. The present clinical article demonstrates a rare anatomical complexity in the mesial root of a mandibular first molar. Four independent root canal orifices were found in this root by clinical detection with the aid of a dental operating microscope. This case shows that additional canals can be located in any root undergoing endodontic treatment and clinicians should always be aware of aberrant internal anatomy.

Analysis of Tooth Access Opening by Students Who Have Completed a Course in Endodontic Practice (Part II. Upper Premolars)

Our dental university has allocated time for endodontic practice to 4th-grade students who have completed a 3rd-grade course in endodontics. In this term, students to practice access opening of extracted upper and lower human molars. All the teeth are donated by students themselves, and the effectiveness of this approach for teaching has been analyzed. Students found 3 root canal orifices in 82.1% of upper molars with 3 root canal orifices, and 3 root canal orifices in 87.5% of lower molars with 3 root canal orifices and 2 root canal orifices in 87.1% of lower molars with 2 root canal orifices. No appreciable difference in ease of access opening was observed between upper and lower molars. Perforation occurred about 20% more frequently in upper than in lower molars. Knowledge of tooth anatomy is essential for students studying endodontic practice. Future efforts should be directed at improving endodontic education to ensure that failure does not occur in practice.

Root canal treatment of maxillary second premolar with three roots and three canals: clinical cases

An accurate diagnosis of the anatomy of the root canal system is a prerequisite for successful root canal treatment. According to the endodontic literature, maxillary second premolars usually have one root and one canal. The possibility of three roots and three canals in maxillary second premolars is quite small. Diagnostic means such as preoperative radiographs and examination of the pulp chamber floor aid the location of root canal orifices. The aim of this clinical article is to describe the unusual anatomy that was detected in two maxillary second premolars during routine endodontic treatment.

MTA versus Portland cement as repair material for furcal perforations: a laboratory study using a polymicrobial leakage model

To compare the ability of Portland cement and mineral trioxide aggregate (MTA) to prevent coronal leakage through repaired furcal perforations in molar teeth. The pulp chambers of 36 human mandibular molar teeth were accessed and the root canal orifices were located. The roots were horizontally sectioned in the middle third. Composite resin was used to fill the root canal orifices and the apical end of the roots. Perforations were created in the centre of the pulp chamber floor using a size 3 round bur. Thirty teeth were divided into two groups (n = 15) and a further six teeth served as controls. In G1, all 15 perforation defects were repaired with MTA while in G2, Portland cement was used. Each tooth was inserted in a silicone tube (bacterial reservoir) with the region containing the perforation protruding through the end. The system was sterilized and placed in a glass flask containing sterile brain heart infusion medium (BHI). The reservoirs were filled with human saliva mixed in BHI and system was incubated at 37 degrees C and checked daily for the appearance of turbidity in the BHI broth during the following 50 days. The leakage data were analysed statistically by a log-rank test (P < 0.05). Eight (53%) of the 15 samples of the MTA group (G1) and nine (60%) of the 15 samples of the Portland cement group (G2) were fully contaminated at 50 days. There was no statistically significant difference between the two groups (P > 0.05). Portland cement and MTA demonstrated a similar ability to seal furcal perforations.

Analysis of Tooth Access Opening by Students Who Have Completed a Course in Endodontic Practice (Part I. Molars)

Our dental university has allocated time for endodontic practice to 4th-grade students who have completed a 3rd-grade course in endodontics. In this term, students to practice access opening of extracted upper and lower human molars. All the teeth are donated by students themselves, and the effectiveness of this approach for teaching has been analyzed. Students found 3 root canal orifices in 82.1% of upper molars with 3 root canal orifices, and 3 root canal orifices in 87.5% of lower molars with 3 root canal orifices and 2 root canal orifices in 87.1% of lower molars with 2 root canal orifices. No appreciable difference in ease of access opening was observed between upper and lower molars. Perforation occurred about 20% more frequently in upper than in lower molars. Knowledge of tooth anatomy is essential for students studying endodontic practice. Future efforts should be directed at improving endodontic education to ensure that failure does not occur in practice.

Three-Dimensional Observation of the Pulp Cavity of Mandibular First Molars by Micro-CT

Aim : To observe the age-related three dimensional morphological and quantitative changes in the pulp cavity and root canal orifices of mandibular first molars by Micro-CT Methodology : In each age group (20's, 40's and 60's), ten mandibular first molars without any substance defects or caries were examined using Micro-CT The pulp cavity of each tooth was reconstructed in three dimensions. Then, the volume ratio of the pulp cavity and the diameter and angle of root canal orifices were examined. Results : With age, the volume ratio of the pulp cavity decreased, and the diameter of root canal orifices also decreased. With regard to the root canal angle in the orifice region, the angle of the mesio-buccal and mesio-lingual root canals decreased, but there was no marked change in that of the distal root canals. Conclusions : The morphology and volume ratio of the pulp cavity of the mandibular first molar changed with age. The morphological changes of the orifice region were particularly specific. The angle of mesio-buccal and mesio-lingual root canal increase was age-related, but with the distal root canal, the degree of change was small and insignificant.

Endodontic treatment of primary teeth using a combination of antibacterial drugs.

To evaluate the clinical outcome of 'Lesion Sterilization and Tissue Repair' (LSTR) therapy for endodontic treatment of primary teeth. A mixture of metronidazole, ciprofloxacin, and minocycline (3Mix) in ointment (macrogol mixed with propylene glycol: MP) or in a root canal sealer was used to disinfect infected root canals of 56 patients aged 4-18 years. Out of a total of 87 primary teeth, 81 cases had physiologic root resorption. A total of 54 radiolucent periradicular lesions were present. The root canals were not prepared before or after disinfection. 3Mix medicament (3Mix-MP/3Mix-sealer) was placed at orifices of root canals or on the bottom of pulp chambers, and then sealed with glass-ionomer cement and further reinforced by a composite resin inlay prepared using a direct method and cemented with resin. In all cases, clinical symptoms such as gingival swelling (52 cases), sinus tracts (22 cases), induced dull pain (3 cases), spontaneous dull pain (26 cases), and pain on biting (46 cases) disappeared after treatment, although in four cases clinical signs and symptoms were finally resolved only after retreatment using the same procedures. Thus, gingival abscesses and fistulae, if present, disappeared after a few days. Successor permanent teeth erupted without any disorders, or were found radiographically to be normal and in the process of eruption. All the cases were evaluated as successful. The mean function time of the primary teeth was 680 days (range: 68-2390 days), except for one case in which the successor permanent tooth was congenitally missing. Primary teeth with periradicular lesions with or without physiologic root resorption were treated successfully by the LSTR endodontic therapy.

Anatomy of the Pulp-Chamber Floor

Locating the number and position of orifices on pulp-chamber floors can be difficult. This is especially true when the tooth being treated is heavily restored, malposed, or calcified. After evaluating 500 pulp chambers of extracted teeth, new laws for finding pulp chambers and root-canal orifices are proposed. The use of these laws can aid in the determination of the pulp-chamber position and the exact location and number of root canals in any individual tooth.

Preparation of root canal orifices by Er:YAG laser irradiation: in vitro and clinical observations.

The purpose of the present study was to evaluate the effectiveness of Er:YAG laser irradiation for preparation of root canal orifices in extracted human teeth and several clinical cases. Few studies with sufficient data have been conducted in this area. Orifices of 42 extracted human teeth were prepared by conventional methods using a Peeso reamer or Er:YAG laser device at 250 mJ/pulse and 8 Hz. In the clinical study, the orifices of 11 teeth from 11 patients with irreversible pulpitis were prepared by Er:YAG laser irradiation at 160 mJ/pulse and 8 Hz. Teeth were carefully irradiated using non-contact methods. Evaluation was performed by visual inspection, stereoscopy, radiography, and scanning electron microscopy (SEM). In addition, the efficiency of using the Er:YAG laser was evaluated. In the in vitro study, canal orifices were clearly exposed by laser irradiation in all specimens. In 31 of 36 teeth (86%), orifices were successfully prepared without ledge formation or perforation. SEM observations revealed that irradiated surfaces were slightly rough and scaly, but essentially free from debris and smear layer. In the clinical study, orifices were successfully prepared in 10 of 11 teeth (91%), and no ledge formation or perforation was observed. These results suggest that the preparation of root canal orifices by Er:YAG laser irradiation may be useful in most cases, if appropriate parameters are selected.