Roots Of Molar Teeth Research Articles

Effect of Reciproc blue, XP-endo shaper, and WaveOne gold instruments on dentinal microcrack formation: A micro-computed tomographic evaluation.

The purpose of this study was to evaluate and compare the effect of Reciproc Blue (RPCB), XP-endo Shaper (XPS), and WaveOne Gold (WOG) single-files on dentinal microcrack formation using micro-computed tomography (micro-CT). Twenty-four mesial roots (24 mesio-buccal and 24 mesio-lingual canals) of mandibular molar teeth were prepared using RPCB, XPS, and WOG files (n = 8/each group). The samples were scanned with micro-CT in the pre- and post-preparation. Then, before preparation and after preparation cross-sectional images of the teeth were evaluated to detect the presence of microcracks. For each group, the number of microcracks was calculated as a percentage rate. The data were statistically analyzed using McNemar at 5% significance level (p < .05). Dentinal microcracks were observed in 25.99% (2,103 of 7,813), 31.99% (2,482 of 7,758), and 36.66% (2,836 of 7,731) of cross-sectional images of the XPS, WOG, and RPCB groups, respectively. In all the groups, all the dentinal microcracks seen in the post-treatment cross-sectional images were present in the corresponding pre-treatment images. Within the limitations of this study, the XPS, WOG, and RPCB files did not cause new dentinal microcrack formation or propagation of existing dentinal microcracks.

Diagnostic Approach and Surgical Management of a Maxillary Molar Tooth Root Infection in a Red-Necked Wallaby (Macropus rufogriseus) Carrying a Joey

Diagnostic Approach and Surgical Management of a Maxillary Molar Tooth Root Infection in a Red-Necked Wallaby (Macropus rufogriseus) Carrying a Joey

Oral and Dental Examination Findings in Beech Martens (Martes foina)

Detailed clinical and radiographical descriptions of oral/dental pathology in the beech marten (Martes foina) are lacking. In the present study, skulls of M. foina from a museum collection (n=109) were examined macroscopically according to predefined criteria and full-mouth dental radiographs were obtained. Occlusion was diagnosed as 'scissor bite' in 22.5% of evaluated skulls, 77% of evaluated skulls showed 'level bite' of incisors and 9.2% of evaluated skulls had 'open bites'. In three skulls, class III malocclusion was diagnosed. Linguoversion of the mandibular second incisor teeth was noted in all skulls. Of the maximum possible number of teeth (i.e. full set of teeth in each skull), 90.4% were available for examination, 6.4% were missing artifactually, 2.0% were absent presumably congenitally and in 1.2 % the absence was presumably acquired. In three skulls supernumerary teeth were noted, all being incisor teeth. In four skulls, unerupted maxillary canine teeth were noted and in one skull odontodysplasia of the maxillary canine teeth was diagnosed. All other teeth were considered normal in morphology. The number of roots per tooth varied in the mandibular second premolar, maxillary first molar and mandibular second molar teeth. The most common dental pathology was attrition/abrasion with 72 skulls (66%) and 857 teeth (24.1% of evaluated teeth) affected, followed by periodontal disease affecting 52 (47.7%) of skulls and 773 teeth (18.9% of evaluated teeth). Dental fractures were present in 49 (45%) skulls and 148 teeth (3.8% of evaluated teeth). Radiographically evident periapical lesions were detected in 11 (10.1%) skulls and 18 teeth (0.5% of evaluated teeth). Other rare abnormal findings included tooth resorption, enamel hypoplasia/hypocalcification, fenestrations at palatal root of maxillary first molar tooth and different bony changes.

Comparative evaluation of apical constriction position in incisor and molar teeth: An in vitro study.

Objective:The apical constriction (AC) and the apical foramen (AF) are the principal reference points used to determine the apical limit for instrumentation and root canal filling. AC varies in different races, and the aim of the current study was to measure and compare the distances from AC to AF and the anatomical apex (AA) in incisor and molar teeth in the Iranian population.Materials and Methods:Forty-five roots of incisor teeth and 45 roots of molar teeth were selected randomly in Isfahan Province, Iran. If the foramen was located toward the mesial or distal side of the apex, the cut was made mesiodistally, and if it was toward the buccal or lingual side, the section was made accordingly. Roots were examined under a microscope at ×25 magnification. The distances from AC to AF and AA were then estimated using a Motic camera. Descriptive statistics were used. The independent t-test was also used to compare distances in incisors and molars, and P = 0.05 was deemed to indicate statistical significance.Results:The mean distances between AC and AF were 0.847 ± 0.33 mm in incisors and 0.709 ± 0.27 mm in molars. The mean distances between AC and AA were 1.23 ± 0.39 mm in incisors and 1.01 ± 0.38 mm in molars. In an independent t-test, the distances between AC and AF differed significantly in incisors and molars (P = 0.035), but the distances between AC and AA did not (P = 0.172).Conclusion:The end points for root canal therapy should be 0.85 mm in incisors and 0.70 mm in molars.

Comparison of apical sealability of three obturation techniques (an in vitro study)

The aim of this study was to evaluate the sealing ability and the time required tocomplete obturationof three different obturation techniques.The palatal roots of sixtymaxillary first molar teeth were selectedfor this study. The root canals prepared usingProFile rotary instruments to an apical dimension of size 40 (.06 taper). Thespecimenswere then randomly divided into 3 experimental groups (20 sample of each) and filledwith gutta-percha and sealer byusing either cold lateral compaction, Thermafil, or theEasy &amp; Quick Master system.For the first parameter(Time of obturation), the resultsshowed that Thermafil technique required the least time to complete obturation and itwas significantly lower than other twogroups.The second measurement(Microleakage) showed that the lateral condensation technique leaked apically andsignificantly higher than other test groups, while the Thermafil group exhibited theleast value of apical microleakage.

Electromagnetic Response of Bones Adjacent to the Dental Root Before and After Dental Implantation.

The aim of this study was relative variation quantification of the total electric field (EF) sum in a region very close to a dental root of the first molar tooth for two different materials: dentine (before implantation) and titanium (present in a screw after implantation), due to development of electrical charges generated by chewing force on the tooth. Because bone is a piezoelectric material, mechanical strain that is generated by chewing force on bone adjacent to the dental root produces electrical charges. Relative variations in the EF sum values with distance of nodes from the centerline of the root was observed for both cases and studied for two different boundary voltage conditions. Simulation and analysis were performed using the commercial finite-element analysis package ANSYS14. The detailed convergence analysis validated the effectiveness and accuracy of finite-element simulations. Before and after implantation, a significant variation in generation of electric charges at adjacent bone of the dental root was observed. We found that the differences in stress generation at the adjacent bone for those cases were just 5%, on average.

Harmine promotes molar root development via SMAD1/5/8 phosphorylation

Tooth and bone are major tissues involved in physiological calcification in the body, and they use similar molecular pathways for development, homeostasis, and regeneration. Harmine (HMN) is a natural small compound that stimulates osteoblast differentiation in vitro and in vivo. Here we examined the biological effect of HMN on the postnatal development of molar tooth roots and periodontal tissues. HMN supported the formation of tooth roots and periodontal tissues in developing tooth germs. In tooth germ organ culture, HMN promoted the elongation of Hertwig's epithelial root sheath (HERS) and stimulated cell proliferation in HERS and dental follicle-derived tissues, including dental papillae and dental follicles. HMN stimulated cell proliferation and cell movement of HERS-derived cells without mesenchymal cells in vitro and directly induced the phosphorylation of SMAD1/5/8 protein in HERS-derived cells. Our results indicated that HMN was the first natural small compound to stimulate postnatal development of tooth germs.

Mandibular Buccal Bone Thickness In Southeastern Anatolian People: A Cone-Beam Computed Tomography Study

Aim: Buccal bone thickness is an important factor in implant treatment, bone health after tooth extraction, apical surgery, and esthetic outcomes. We evaluated the distance from the mandibular premolar and molar teeth apices to the buccal cortical bone in southeastern Anatolian people using cone-beam computed tomography (CBCT).&#x0D; Methodology: This retrospective study was performed in 461 posterior teeth (220 premolars, 241 molars) of 133 patients (62 females, 64 males) at Dicle University, Faculty of Dentistry, Department of Oral and Maxillofacial Radiology. Data were analyzed using Student’s t-tests and Tukey HSD tests.&#x0D; Results: The mandibular buccal bone was thicker in men than in women, but the difference was not statistically significant (p&gt;0.05). The thinnest point of the mandibular buccal bone was measured in women as 2.431 mm and in men as 2.491 mm in the first premolar teeth. The thickest point of the mandibular bone was measured in women as 7.940 mm and in men as 7.859 mm in the distal roots of mandibular second molar teeth. For the mandibular first and second premolars, there was no significant difference in buccal bone thickness among the 10–29-, 30–49-, and 50–69-year age groups. The difference between the first and second molar mesial and distal roots of the age groups was significant at the level of buccal root thickness (p&lt;0.05).&#x0D; Conclusions: It is important to examine buccal bone thickness (with CBCT) before surgical dental procedures for appropriate implant planning and surgical endodontic treatment. &#x0D; How to cite this article: Aktuna Belgin C, Adiguzel O, Bud M, Colak M, Akkus Z. Mandibular Buccal Bone Thickness In Southeastern Anatolian People: A Cone-Beam Computed Tomography Study. Int Dent Res 2017;7:6-12.&#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Zirconia implants and peek restorations for the replacement of upper molars

BackgroundOne of the disadvantages of the zirconia implants is the lack of elasticity, which is increased with the use of ceramic or zirconia crowns. The consequences that could result from this lack of elasticity have led to the search for new materials with improved mechanical properties.Case presentationA patient who is a 45-year-old woman, non-smoker and has no medical record of interest with a longitudinal fracture in the palatal root of molar tooth 1.7 and absence of tooth 1.6 was selected in order to receive a zirconia implant with a PEEK-based restoration and a composite coating. The following case report describes and analyses treatment with zirconia implants in molars following a flapless surgical technique. Zirconia implants are an alternative to titanium implants in patients with allergies or who are sensitive to metal alloys. However, one of the disadvantages that they have is their lack of elasticity, which increases with the use of ceramic or zirconia crowns. The consequences that can arise from this lack of elasticity have led to the search for new materials with better mechanical properties to cushion occlusal loads. PEEK-based restoration in implant prosthetics can compensate these occlusal forces, facilitating cushioning while chewing.ConclusionThis procedure provides excellent elasticity and resembles natural tooth structure. This clinical case suggests that PEEK restorations can be used in zirconia implants in dentistry.

Apical Root Canal Morphology of Mesial Roots of Mandibular First Molar Teeth with Vertucci Type II Configuration by Means of Micro–Computed Tomography

IntroductionThe aim of this study was to assess the features of the apical root canal anatomy and its relation to the level at which 2 separate root canals merge in the mesial roots of the mandibular first molars with Vertucci type II canal configuration by using micro–computed tomography analysis. MethodsThe anatomic features of the apical 3 mm of root canals in 83 mesial roots of mandibular first molar teeth were investigated by micro–computed tomography and software imaging according to the level at which 2 separate root canals merge. The most apical slice where a visible root canal was detectable was recorded as 0 level. The specimens from where 2 root canals rejoin at within 3 mm from the 0 level were then assigned to group 1 (n = 37), whereas the specimens from where root canals rejoin 3–9 mm from the 0 level were assigned to group 2 (n = 46). Data were presented by using descriptive statistics and Mann-Whitney U tests, with the significance level set at 5%. ResultsIn all specimens the long oval type of cross-sectional shape increased from 50.9% at 1 mm to 80.5% at 3 mm. Group 1 presented significantly higher major diameter values compared with group 2 (P < .05). There was no significant difference regarding minor diameter values (P > .05) between groups. Group 2 displayed significantly higher roundness values than group 1 (P < .05). ConclusionsA long oval root cross section of apical root canal anatomy is more prevalent in roots for which 2 root canals merge within apical 3 mm of root canals.

Evaluation of various filling techniques in distal canals of mandibular molars instrumented with different single-file nickel-titanium systems.

The aim of this study was to evaluate the quality of various filling techniques in distal canals of mandibular molars instrumented with different single-file nickel-titanium (NiTi) systems. A total of 150 distal roots of mandibular molar teeth were randomly assigned into three main groups and instrumented by using Reciproc (VDW, Munich, Germany), WaveOne (Dentsply Tulsa, Tulsa, OK, USA), or One Shape (MicroMega, Besancon, France) NiTi file systems. The roots were then treated using one of five filling techniques: (1) Matched-single-cone, (2) cold lateral compaction with matched gutta-percha (GP) cone, (3) Thermafil filling, (4) System B/Obtura II, and (5) lateral compaction with standardized GP cones. The roots were then sectioned at three levels (coronal, middle, and apical). Photographs were acquired under a stereomicroscope, and the percentage of GP-filled areas (PGFAs), percentage of sealer-filled areas (PSFAs), and voids were measured using the ImageJ software. Comparisons between groups were applied using Student's t-test or one-way ANOVA for normally distributed data. The Mann-Whitney U-test or Kruskal-Wallis test was used when variables were not normally distributed. Canals filled with the System B/Obtura showed the highest PGFA and lowest PSFA, whereas those filled with matched-single-cone showed the highest PSFA and lowest PGFA (P < 0.05). The cold lateral compaction with matched GP cone group, lateral compaction group, and Thermafil filling group showed no statistically significant differences in PSFA and PGFA (P > 0.05). System B/Obtura technique appears to be the best technique to properly fill root canals, whereas the matched-single-cone technique in oval-shaped distal canals of mandibular molars was inadequate.

Mandibular Birinci Molar Dişlerin Mezial Köklerindeki Apikal Delta Morfolojisinin Kantitatif İncelenmesi: Bir Mikro-BT Çalışması

Objective: The apical delta is the branching of the main root canal dividing into three or more ramifications near the root apex, while the main canal itself becoming indistinguishable. Aim of this study was to analyze apical delta morphologies of mesial root canals of mandibular first molar teeth quantitatively using micro-computed tomography (micro-CT). Material and Methods: Two hundred and sixty-nine mesial roots of mandibular first molar teeth were scanned by micro-CT. Following the initial scanning, 22 specimens showing apical delta ramifications were selected from reconstructed micro-CT images. The numbers and vertical extension of the apical ramifications were recorded. For each specimen, major diameter, minor diameter and roundness values at the most apical slices of the apical delta ramifications and at the slice where ramifications merged to form to main canal were calculated. Data were analyzed using descriptive statistics. Results: The incidence of apical delta was 13.01%. A total of 96 apical delta ramifications were quantitatively analyzed. The mean number of apical delta ramifications was 4.45 per specimen and the mean vertical extension was 0.95 mm. Majority of the apical delta ramifications exhibited noncircular cross sectional shape. Conclusion: The occurrence of apical delta is not uncommon in clinical practice. The shape, number and the height of the apical delta are variable. These complex morphological properties of apical delta might complicate three-dimensional shaping and obturation of root canal systems.

Multiple essential MT1-MMP functions in tooth root formation, dentinogenesis, and tooth eruption

Membrane-type matrix metalloproteinase 1 (MT1-MMP) is a transmembrane zinc-endopeptidase that breaks down extracellular matrix components, including several collagens, during tissue development and physiological remodeling. MT1-MMP-deficient mice (MT1-MMP−/−) feature severe defects in connective tissues, such as impaired growth, osteopenia, fibrosis, and conspicuous loss of molar tooth eruption and root formation. In order to define the functions of MT1-MMP during root formation and tooth eruption, we analyzed the development of teeth and surrounding tissues in the absence of MT1-MMP. In situ hybridization showed that MT1-MMP was widely expressed in cells associated with teeth and surrounding connective tissues during development. Multiple defects in dentoalveolar tissues were associated with loss of MT1-MMP. Root formation was inhibited by defective structure and function of Hertwig's epithelial root sheath (HERS). However, no defect was found in creation of the eruption pathway, suggesting that tooth eruption was hampered by lack of alveolar bone modeling/remodeling coincident with reduced periodontal ligament (PDL) formation and integration with the alveolar bone. Additionally, we identified a significant defect in dentin formation and mineralization associated with the loss of MT1-MMP. To segregate these multiple defects and trace their cellular origin, conditional ablation of MT1-MMP was performed in epithelia and mesenchyme. Mice featuring selective loss of MT1-MMP activity in the epithelium were indistinguishable from wild type mice, and importantly, featured a normal HERS structure and molar eruption. In contrast, selective knock-out of MT1-MMP in Osterix-expressing mesenchymal cells, including osteoblasts and odontoblasts, recapitulated major defects from the global knock-out including altered HERS structure, short roots, defective dentin formation and mineralization, and reduced alveolar bone formation, although molars were able to erupt. These data indicate that MT1-MMP activity in the dental mesenchyme, and not in epithelial-derived HERS, is essential for proper tooth root formation and eruption. In summary, our studies point to an indispensable role for MT1-MMP-mediated matrix remodeling in tooth eruption through effects on bone formation, soft tissue remodeling and organization of the follicle/PDL region.

Estudo anatômico do trajeto do canal mandibular em felinos (Felis catus domesticus)

Objetivou-se descrever, por meio de tomografia computadorizada, o trajeto do canal mandibular (CM) em 20 gatos sem raça definida, com ausência de alterações na cavidade oral, provenientes do Centro de Controle de Zoonoses do Distrito Federal. Foram realizados cortes tomográficos com 2mm de espessura, acompanhando todo o trajeto do CM, tendo como referência a região do forame mandibular, as raízes distais e mesiais dos dentes pré-molares e molares e o forame mentoniano, obtendo-se medidas desde o CM até as faces vestibular, lingual, ventral e alveolar (profundidade) do corpo da mandíbula, bem como seu diâmetro. Pôde constatar que o CM manteve-se no aspecto lingual do corpo da mandíbula desde o forame mandibular até a raiz mesial do 1º pré-molar, onde se deslocou para a face vestibular, emergindo no forame mentoniano. Com relação à profundidade, seu trajeto sofreu declive a partir do forame mandibular até a região da raiz mesial do 1º molar, onde alcançou seu ponto mais profundo para prosseguir em suave ascensão até o forame mentoniano. Os dados apresentados contribuem para o estudo anatômico da mandíbula de gatos, bem como auxiliam no melhor planejamento e execução de procedimentos cirúrgicos na mandíbula dessa espécie.

Cementoblastoma: A case report

Benign cementoblastoma is a rare odontogenic tumour characterized by the formation of a mass of cementum or cementum like tissue attached to the roots of the tooth. It is probably a true neoplasm of functional cementoblasts that usually occurs around the root of a mandibular premolar or molar tooth. Cementoblastoma are slow growing lesions and are usually asymptomatic; however pain and swelling may occur. Thus this case report reveals that cementoblastoma is usually asymptomatic and slow growing lesions but associated with pain and swelling. This report presents a large cementoblastoma of the right mandibular body, extending from the first premolar to the second molar, in a 23-years-old male patient which was confirmed by its radiological and histopathological features.

Evaluation of surface alterations in different retreatment nickel-titanium files: AFM and SEM study.

The aim of this study was to evaluate the surface changes of nickel titanium (Ni-Ti) rotary retreatment files after three and five uses. Furthermore, the effects of 2% sodium hypochlorite and chloroform solutions and sterilization procedures on the NiTi rotary retreatment surfaces were investigated. ProTaper Retreatment files, R-endo files, and Mtwo retreatment files were used for this study. The palatinal roots of maxillary molar teeth were obturated with gutta percha and Ah26. Retreatment procedures were performed with these retreatment file systems. The surface changes of untreated NiTi rotary files that were used three and five times, immersed in NaOCl and chloroform and subjected to sterilization procedures were investigated with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The RMS values, three dimensional images and SEM images at various magnifications were obtained. RMS values showed that all three NiTi rotary retreatment file systems showed significant deteriorations after three and five uses. Cracks, damages and spiral construction deteriorations were detected in the SEM images after three and five uses. Furthermore, the Mtwo 15 file was broken off after five uses. AFM data indicated that 2% NaOCl caused significant surface deteriorations on NiTi rotary files and both AFM and SEM evaluation showed that chloroform solution and sterilization procedures did not cause significant surface deteriorations. In conclusion, ProTaper retreatment, R-endo, and Mtwo retreatment files showed surface damages depending on retreatment procedures. Clinicians have to consider that retreatment files always have a tendency to break off after the third time they have been used.

Parturition lines in modern human wisdom tooth roots: do they exist, can they be characterized and are they useful for retrospective determination of age at first reproduction and/or inter-birth intervals?

Background: Parturition lines have been described in the teeth of a number of animals, including primates, but never in modern humans. These accentuated lines in dentine are comprised of characteristic dark and light component zones.Aim: The aim of this study was to review the physiology underlying these lines and to ask if parturition lines exist in the third molar tooth roots of mothers known to have had one or more children during their teenage years.Methods: Brief retrospective oral medical obstetric histories were taken from four mothers and compared with histological estimates for the timing of accentuated markings visible in longitudinal ground sections of their wisdom teeth.Results: Evidence of accentuated markings in M3 root dentine matched the age of the mother at the time their first child was born reasonably well. However, the dates calculated for inter-birth intervals did not match well.Conclusions: Parturition lines corresponding to childbirth during the teenage years can exist in human M3 roots, but may not always do so. Without a written medical history it would not be possible to say with confidence that an accentuated line in M3 root dentine was caused by stress, illness or was a parturition line.

Evaluation of Root Canal Configuration of Maxillary Molars in a Brazilian Population Using Cone-beam Computed Tomographic Imaging: An In Vivo Study

IntroductionThe aim of this study was to analyze and characterize root canal morphology of maxillary molars of the Brazilian population using cone-beam computed tomographic (CBCT) imaging. MethodsPatients referred for a CBCT radiographic examination for accurate diagnosis and treatment planning were enrolled in the study. A total of 620 healthy, untreated, fully developed maxillary first and second molars were included (314 first molars and 306 second molars). The following observations were recorded: (1) number of roots and their morphology, (2) number of canals per root, (3) fused roots, and (4) primary variations in the morphology of the root canal systems. ResultsFirst and second molars showed a higher prevalence of 3 separate roots, mesiobuccal, distobuccal, and palatal, with 1 canal in each root (52.87% and 45.09%, respectively). Two canals in the mesiobuccal roots represented 42.63% of teeth, whereas mesiobuccal roots of second molars presented 2 canals in 34.32%. The most common anatomic variation in the maxillary first molar was related to the root canal configuration of the mesiobuccal root, whereas the root canal system of the maxillary second molar teeth showed more anatomic variables. ConclusionsMesiobuccal roots of maxillary molar teeth had more variation in their canal system than the distobuccal or palatal roots. The root canal configuration of the maxillary second molars was more variable than the first molars in a Brazilian population. CBCT imaging is a clinically useful tool for endodontic diagnosis and treatment planning.

A comparison of four nickel titanium rotary systems, quantec series, k3 endo, race and hero 642 for canal cleaning ability - An in vitro study

Background And Objectives : To compare in-vitro, the cleaning effectiveness of pulp space preparation under Scanning electron microscope (SEM) using four different NiTi rotary instrumentation systems – Quantec SC, K3 Endo, RaCe and HERO 642. Materials and Method : Forty-eight freshly extracted palatal roots of human maxillary first molar teeth were procured, stored and surfaced adhering to infection control protocols in the laboratory as prescribed by Centre for Disease Control Global. Random sampling of specimens into four groups of ten teeth each and one group of eight teeth was done. Groups I, II, III & IV served as experimental with Group V as control. Access cavities were prepared in all groups and working length was determined only in experimental groups. Control group remained non-instrumented. Cleaning and shaping was done for experimental groups only. Teeth were prepared to # 40 master apical file using crown down technique. The experimental groups: I. Teeth with Pulp space instrumented with Quantec SC. II. Teeth with Pulp space instrumented with K3 Endo. III. Teeth with Pulp space instrumented with RaCe. IV. Teeth with Pulp space instrumented with HERO 642. V. Control group: Teeth with pulp space not instrumented. Thereafter all teeth were longitudinally sectioned buccolingually and examined under SEM at 20.0 kV and 500 X magnifications in the middle third of the canal. Debris was defined as dentin chips, pulp remnants, and particles loosely attached to the root canal wall. Analysis of SEM images was performed using following five score index:-Numerical Evaluation (Scoring System): Score 1 – Clean root canal walls, only few small debris particles. Score 2 - Few small agglomeration of debris. Score 3- Many agglomerations of debris covering less than 50% of the root canal wall. Score 4- More than 50% of the root canal wall covered with debris. Score 5- Complete or nearly complete root canal walls covered with debris. Statistical Analysis : Kruskal Wallis test was used to determine whether a statistical difference existed amongst the four group of instruments, with P < 0.001, considered to be statistically very highly significant. Whitney Mann -U test for individual intergroup comparison and “CHI-square” test was used to detect frequency of individual debris score in each tested groups followed by Kendell’s tau-b test to measure observer agreement. Results : Teeth with pulp space instrumented with RaCe system exhibited maximum canal cleanliness compared to the other experimental groups. The differences observed within the groups were statistically very highly significant (p<0.001). Conclusion : Post pulp space preparation with four different NiTi rotary systems, statistically very highly significant differences in canal wall cleanliness at the midroot level was achieved. Under the conditions of this study, best canal cleaning efficacy was achieved by RaCe, followed by HERO 642, K3 Endo and Quantec SC.

Five Root Canals for a Maxillary First Molar Tooth – A Case Report

This case report represents assessment and management of a maxillary left first molar tooth containing five root canals by endodontic treatment. In this case Mesiobuccal 2 (MB2), Mesiopalatal (MP) and Distobuccal (DB) canals were missed as well as very poor obturation at palatal and mesiobuccal1(MB1) canal during previous treatment history. Three mesiobuccal (MB1, MB2, and MP), DB and palatal canals were identified and endodontic retreatment was done followed by final restoration. This case provides an evidence of variations in the root canals of the mesiobuccal root of maxillary first molar tooth. Complete clinical and radiographic examination and adequate knowledge of the morphology of this kind of teeth is necessary for successful clinical outcome.DOI: http://dx.doi.org/10.3329/bsmmuj.v5i1.11026 BSMMU J 2012; 5(1):61-64