• Restorative Dentistry and Endodontics
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• v.40 no.1
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• pp.75-78
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• 2015

Presented here is a case where 8 canals were located in a mandibular first molar. A patient with continuing pain in mandibular left first molar even after completion of biomechanical preparation was referred by a dentist. Following basic laws of the pulp chamber floor anatomy, 8 canals were located in three steps with 4 canals in each root. In both of the roots, 4 separate canals commenced which joined into two canals and exited as two separate foramina. At 6 mon follow-up visit, the tooth was found to be asymptomatic and revealed normal radiographic periapical area. The case stresses on the fact that understanding the laws of pulp chamber anatomy and complying with them while attempting to locate additional canals can prevent missing canals.

• Imaging Science in Dentistry
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• v.43 no.4
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• pp.309-312
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• 2013

A retromolar canal is an anatomical variation in the mandible. As it includes the neurovascular bundle, local anesthetic insufficiency can occur, and an injury of the retromolar canal during dental surgery in the mandible may result in excessive bleeding, paresthesia, and traumatic neuroma. Using imaging analysis software, we evaluated the cone-beam computed tomography (CT) images of two Korean patients who presented with retromolar canals. Retromolar canals were detectable on the sagittal and cross-sectional images of cone-beam CT, but not on the panoramic radiographs of the patients. Therefore, the clinician should pay particular attention to the identification of retromolar canals by preoperative radiographic examination, and additional cone beam CT scanning would be recommended.

• Restorative Dentistry and Endodontics
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• v.38 no.4
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• pp.222-226
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• 2013

Objectives: The aim of this study was to assess the influence of operator experience level on the lifespan of the WaveOne Primary file (Dentsply Maillefer, Ballaigues, Switzerland) in extracted teeth. Materials and Methods: Moderately curved canals of extracted maxillary and mandibular molars were randomly distributed into 2 groups: experienced and inexperienced operators. Ten files were allocated to each group (n = 10). Each canal was prepared until the working length was reached, and the same file was used to prepare additional canals until it separated. The number of canals prepared before file separation was recorded. The fragment length of each file was measured, and the location of the fragment in the canal was determined. Data were statistically analysed using the independent 2-sample t-test. Results: The 2 operators prepared a total of 324 moderately curved canals of maxillary and mandibular molars. There was no significant intergroup difference in the mean number of canals prepared (p = 0.27). The average lifespan of the WaveOne Primary file was 17.1 and 15.3 canals, and the longest lifespan was 25 and 20 canals, when used by experienced and inexperienced operators, respectively. There were no statistically significant intergroup differences in separated fragment length and location. Conclusions: Within the limitations of this study, operator experience level appears to have no effect on the lifespan of the WaveOne Primary file in preparation of moderately curved canals. Single teeth with multiple canals can be prepared safely even by a novice operator by using a single file.

• Restorative Dentistry and Endodontics
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• v.40 no.3
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• pp.241-248
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• 2015

Variation in root canal morphology, especially in maxillary first molar presents a constant challenge for a clinician in their detection and management. This case report describes the successful root canal treatment of a three rooted right maxillary first molar presenting with three canals each in the mesiobuccal and distobuccal roots and one canal in the palatal root. The clinical detection of this morphologic aberration was made using a dental operating microscope, and the canal configuration was established after correlating and computing the clinical, radiographic and cone-beam computed tomography (CBCT) scan findings. CBCT images confirmed the configuration of the canals in the mesiobuccal and distobuccal roots to be Al-Qudah and Awawdeh type (3-2) and type (3-2-1), respectively, whereas the palatal root had a Vertucci type I canal pattern. This report reaffirms the importance of careful examination of the floor of the pulp chamber with a dental operating microscope and the use of multiangled preoperative radiographs along with advanced diagnostic aids such as CBCT in identification and successful management of aberrant canal morphologies.

• The Journal of the Korean dental association
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• v.56 no.2
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• pp.84-93
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• 2018

Purpose: This study evaluated the apical root canal system of maxillary second molars, in which conventional endodontic treatment had failed. Materials and Methods: One hundred eighteen extracted endodontically failed maxillary second molars were examined to investigate the root canal morphology using clinical photographs. High-resolution cross-sectional images at the 3mm level from the root apices were taken to evaluate the anatomic variations and canal cleanliness. The incidence of anatomic variations and canals containing debris were evaluated statistically. Results: One (0.85%) maxillary second molar had four separate roots, while 52 (44.07%) had three separate roots. The remaining 65 (55.08%) showed 6 different types of fusion in their roots. As the number of fused roots increased from none to three, the incidence of isthmuses in the cross-sectional images increased significantly from 43.40% to 76.92% in 2-root fusion and 88.46% in 3-root fusion. In addition, the occurrence of less-cleansed canals increased from 22.64% to 38.46% and 53.85%, respectively (p<0.05). Sixty four teeth (54.24%) had 3 canals while 38(32.2%) had additional canals; most of them were located in the MB roots (81.58%). Seventy six (64.41%) had isthmuses in the apical region and 58 out of 76 were located in MB roots. Condlusions: Logistic analysis indicated that the less division of roots was associated significantly with the occurrence of insufficient cleaning during endodontic treatment (OR=1.765, p<0.05), while the presence of an additional canal showed no association.

• Proceedings of the KACD Conference
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• 2001.05a
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• pp.259-259
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• 2001

;A new root canal instrument and instrumentation technique: a preliminary report. Cleaning and shaping the root canal system has been and continues to be a challenge for even the most experienced endodontist. Curved. narrow canals. in particular. cause difficulties for the beginner as well as the specialist. A new instrument designed to incorporate new concepts was developed to ameliorate the problems in cleaning and shaping root canal systems. This new instrument has been given the name of SW (Senia and Wildey). The new SW instrument uses controlled right and left rotational forces. This motion was used to clean and shape simulated root canals in plastic blocks and root canals in extracted teeth. Instrumentation appeared to be easier. faster. and more precise than with conventional instruments. especially in curved canals where there was remarkable reduction of canal transportation. A mechanical version of the SW instrument was also developed. It was used to flare the coronal portion of the root canal system. Wildey WL. Senia ES., Oral Surg Oral Med Oral Pathol1989 Feb:67(2):198-207 Another look at root canal instrumentation. Several aspects of root canal instrumentation need additional research. Various factors must be considered in an analysis of instrumentation of the root canal system: the dentin that is cut: the technique used to cut it: the design of the instruments: the material and manufacturing process used to make the instruments: the irrigant used during the procedure: and the anatomic configuration of the root canal system. An analysis of these factors clearly indicates that existing root canal instruments and techniques are less than ideal and. in fact. do not accomplish what is expected of them. Root canals must be properly. but. at the same time. destructive and unnecessary removal of dentin should be kept to a minimum. The Flex-R and Canal Master instruments were developed to address some of the shortcomings of existing instruments and techniques. More scientifically based research is needed to fully evaluate these new instruments and techniques and to develop future instruments. Wildey WL; Senia ES. Montgomery S., Oral Surg Oral Med Oral Pathol1992 Oct:74(4):499-50799-507

• Restorative Dentistry and Endodontics
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• v.29 no.6
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• pp.541-547
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• 2004

The aim of this study was to compare the initial apical file (IAF) length between the mesio-buccanl and mesio-lingual canals of the mandibular molar before and after early coronal flaring. Fifty mandibular molars with complete apical formation and patent foramens were selected. After establishing the initial working length of the buccal and lingual canal of the mesial root using the Root-ZX, radiographs were taken for the working length with a 0.5 mm short of #15 K-file tip just visible at the foramen under a surgical microscope (OPMI 1-FC, Carl Zeiss Co. Germany) at 25X. After early coronal flaring using the $K^3$ file, additional radiographs were taken using the same procedure. The root canal morphology and the difference in working length between the buccal and lingual canals were evaluated. These results show that the difference in the length between the mesio-buccal and mesio-lingual canals of the mandibular molar was $\leq$ 0.5 mm. If one canal has a correct working length for the mesial root of the mandibular molar, it can be used effectively for measuring the working length of another canal when the files are superimposed or loosening. In addition, the measured the working length after early coronal flaring is much more reasonable because the difference in the length between the mesio-buccal and mesio-lingual canals can be reduced.

• Restorative Dentistry and Endodontics
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• v.43 no.3
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• pp.35.1-35.7
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• 2018

The aim of this article was to showcase the endodontic management of a maxillary first molar with an unusual crown and root anatomy. Clinical diagnosis of the roots and root canal configuration was confirmed by a cone-beam computed tomography (CBCT) and the detection of the canals was made using a dental operating microscope. CBCT images revealed the presence of 5 roots with Vertucci type I canal configuration in all, except, in the middle root which had 2 canals with type IV configuration. The 6 canal orifices were clinically visualized under the dental operating microscope. Clinicians should familiarize themselves with the latest technologies to get additional information in endodontic practice in order to enhance the outcomes of endodontic therapy.

• Restorative Dentistry and Endodontics
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• v.6 no.1
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• pp.51-62
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• 1980

A Scanning Electron Microscope study was conducted to compare the effectiveness of mechanical preparation of the root canal in conjunction with a few number of canal irrigants that have been widely used for canal treatment. The irrigants used in this study were 5% sodium hypochlorite, 3% hydrogen peroxide, 15% EDTA, and 30% hydrochloric acid. The root canals of 84 freshly extracted teeth with single or multi root were conventionally prepared with Hedstroem files. 78 canals were irrigated with normal saline solution following each instrument number and 6 canals were prepared without irrigation. After instrumentation 72 canals were flushed with various irrigants for predetermined length of time as shown on the Table 1. Additional 20 teeth were kept uninstrumented and five of them were immersed in 15% EDTA for 5 minutes, five in 5% sodium hypochlorite for 5 minutes, five in 3% hydrogen peroxide for 20 minutes, and the last five were only rinsed with saline solution. The SEM examination revealed as follows: 1. The canal wall cannot be thoroughly prepared by means of files. 2. No typical structural changes occured on instrumented dentin surface by saline solution, 3% $H_2O_2$, 5% NaOCl, within 5 minutes. 3. 5% NaOCl Solution showed excellent solvent effect to organic substances in uninstrumented canal within 5 minutes and 15% EDTA and 3% $H_2O_2$ showed unsignificant changes. 4. 15% EDTA and 30% HCl dissolved calcified debris and dentin chips that obturated the dentinal tubules and showed patent orifices. 5. 15% EDTA affected on peritubular dentin more readily and showed concavity around dentinal tubules.

• Restorative Dentistry and Endodontics
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• v.39 no.1
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• pp.45-50
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• 2014

Ambiguity in the root morphology of the mandibular second molars is quite common. The most common root canal configuration is 2 roots and 3 canals, nonetheless other possibilities may still exist. The presence of accessory roots is an interesting example of anatomic root variation. While the presence of radix entomolaris or radix paramolaris is regarded as a typical clinical finding of a three-rooted mandibular second permanent molar, the occurrence of an additional mesial root is rather uncommon and represents a possibility of deviation from the regular norms. This case report describes successful endodontic management of a three-rooted mandibular second molar presenting with an unusual accessory mesial root, which was identified with the aid of multiangled radiographs and cone-beam computed tomography imaging. This article also discusses the prevalence, etiology, morphological variations, clinical approach to diagnosis, and significance of supernumerary roots in contemporary clinical dentistry.