Root Canals Of Maxillary Molars Research Articles

The Impact of Minimum Invasive Access Cavity Design on the Quality of Instrumentation of Root Canals of Maxillary Molars Using Cone-Beam Computed Tomography: An in Vitro Study.

Aim Minimally invasive dentistry has been facilitated by advances in instruments and restorative materials. This study aims to compare the change in the shaping ability of the RECIPROC blue rotary system in both traditional and conservative access cavities, using cone beam computed tomography (CBCT). Material and methods Sixty root canals of 20 artificial maxillary molars were assigned into two groups (n=30 root canals) according to the access cavity design used: Group I: traditional access cavity (TAC) and Group II: conservative access cavity (CAC). CBCT scans of samples were made before and after root canal preparation using the RECIPROC blue rotary system. The shaping parameters are evaluated in root canal transportation and the centering ability. Three CBCT sections per tooth were analyzed at 3, 6, and 9 mm from the apex to assess the canal transportation and centering ability at three levels, apical, middle, and coronal thirds. Data were analyzed using the GraphPad Prism (GraphPad Software, San Diego, CA). Results The results of this study showed a significant difference in transportation within the coronal and middle thirds. However, in apical thirds, there were no significant differences. Both groups observed a significant difference in the centering ability in the coronal third. Conclusion Within the limitations of this study, CAC can be recommended with caution as an alternative access to TAC.

Effect of ultrasonic agitation on marginal adaptation, intratubular penetration and bonding strength of calcium-silicate-based endodontic sealers: A laboratory study.

The effect of ultrasonic activation (UA) on marginal adaptation, intratubular penetration and bond strength provided by three calcium silicate-based sealers was evaluated. Ninety-six distobuccal root canals of maxillary molars were randomly divided into 8 groups (n = 12) according to the sealer and UA application: EndoSequence BC sealer (ESBC), Sealer Plus BC (SPBC) and Bio-C Sealer (BCS), using AH Plus (AH) as a control group. The specimens were sectioned at 2, 4 and 6 mm from the apex. The data were statistically analysed using Kruskall-Wallis, Dunn, Mann-Whitney and chi-squared tests. UA improved the marginal adaptation of ESBC (6 mm), SPBC (all levels), BCS (2/4 mm) and AH (4 mm) (p < 0.05); the bond strength of SBPC (2 mm) and BCS (6 mm) were also improved (p < 0.05). The UA of endodontic silicate-based sealers improved the marginal adaptation in all levels and the bond strength of SBPC and BCS sealer.

The effect of rotary instrumentational speeds on foraminal deformation: An in vitro study

Introduction: The effect of the rotational speed on the performance of endodontic therapies has been unclear. This study aimed to evaluate the foraminal deformation (FD) caused by two rotary instrument systems with different rotational speeds at three different working length determinations using Scanning electron microscopy is better (SEM). Materials and Methods: Sixty mesiobuccal root canals of maxillary molars were randomly divided into two groups (n = 30 each) and instrumented using either RaCe®Evo (at 1000 rpm and 1 Ncm torque) or TruNatomy (at 500 rpm and 1.5 Ncm torque) 1 mm behind the major foramen (MF) (n = 10), at the MF (n = 10), and 1 mm beyond the MF (n = 10). The roots were scanned under SEM at × 300 magnification and 15.00 kV before and after instrumentation procedures. The pre- and postoperative SEM images were analyzed using the ImageJ software program. The FD was represented with the circularity and Feret’s diameter ratio of the apical foramen. Results: No significant difference was observed in the before and after values of the circularity and Feret’s diameter parameters within and between the rotary instrument groups (P &gt; 0.05). Conclusion: Increasing of the rotational speed had no negative effect on the FD.

Dentine thickness in maxillary fused molars depends on the fusion type: An ex vivo micro-computed tomography study.

The present study aimed to determine and compare the dentine thickness around the root canals of maxillary molars with fusion using micro-computed tomography (micro-CT). A total of 120 fused maxillary molars having more than a single canal with distinct canal orifices near the cementoenamel junction were selected from a pool of extracted maxillary molars, which were scanned on a micro-CT device (SkyScan 1172, Bruker-microCT). The minimum dentine thickness around the root canals in furcal direction was measured using CTAn software (v.1.18.8 Bruker-microCT) at each millimetre. The specimens were grouped according to their fusion type, and dentine thickness around the canals was compared. The data were statistically analysed using anova and post hoc Tukey-Kramer tests following an assessment of the normality of their distribution with the Kolmogorov-Smirnov test (p < .05). Dentine thickness showed a statistically significant decrease at 2 mm apical to the orifice level irrespective of fusion type. The minimum dentine thickness values were detected around the second mesiobuccal canal as 0.30 mm at 6 mm below orifice. Dentine thickness around the mesiobuccal canal was significantly greater in fusion type 1 than those of types 2 and 3 (p < .05), while those of distobuccal and palatal canals were significantly thinner in type 3 fusion compared with type 1 or 6 (pDentine thickness showed a statistically significant decrease at 2 mm apical to the orifice levelirrespective of fusion type. The minimum dentine thickness values were detected around the second mesiobuccal canal as 0.30 mm at 6 mm below orifice. Dentine thickness around the mesiobuccal canal was significantly greater in fusion type 1 than those of types 2 and 3 ( CONCLUSION: Minimum dentine thickness values at the danger zone of distobuccal and palatal canals change according to the fusion type in fused maxillary second molars.

Variables That Affect the Ability to Find the Second Mesiobuccal Root Canals in Maxillary Molars.

The study aimed to investigate the influence of various factors on the localization of the second mesiobuccal (MB2) canal in maxillary molars, a commonly missed canal during endodontic treatment. A comprehensive assessment of maxillary molars treated over three years with a dental operative microscope was conducted. Factors such as patient gender, age, tooth type, pulp status, pre-operative cone-beam computed tomography (CBCT), and treatment modality were examined. Statistical analyses included chi-square and multiple logistic regression. Among 333 treated maxillary molars, the MB2 canal was identified in 60.1%. The prevalence of MB2 canals was significantly higher in the first molars (72.3%) compared to the second molars (40.2%; P=0.001). Multiple logistic regression models showed that gender, tooth type, and treatment modality emerged as significant determinants of MB2 canal localization: males [odds ratio 3.01(CI 95%:1.71-5.32), P<0.001], first molar tooth [odds ratio 4.26 (CI 95%:2.53-7.18), P<0.001] and secondary endodontic treatment [odds ratio 0.06 (CI 95%: 0.004-0.890), P<0.04]. Patient gender, tooth type, and treatment modality play pivotal roles in the identification of the MB2 canal. Additionally, the availability of pre-operative CBCT imaging was associated with a heightened ability to locate the MB2 canal.

CBCT based study to analyze and classify root canal morphology of maxillary molars - A retrospective study.

The study aims to evaluate maxillary molars' root and root canal morphology among the Saudi population using Cone-Beam Computed Tomography scanning (CBCT). Retrospectively, the CBCT scans of 483 Saudi nationals were evaluated to identify the number of roots and root canals in maxillary first and second molars. The records were tabulated and classified according to Vertucci and a new system for root and canal classification given by Ahmed and Dummer. Fisher's exact test was used to analyze the data statistically. To check for symmetry, comparisons were made between all the maxillary first molars (MFM's) and maxillary second molars (MSM's) on opposing quadrants. Inter Observer variability was seen using Cohen's Kappa test. MFM's presented with three roots with Type II Vertucci canal configuration (VC) commonly seen among them. MSM's had more variations in the number of roots and canals, although three roots and Type I VC were predominantly seen. When comparing the two genders statistically significant difference was observed in both maxillary molars at a 5% level using Fisher's exact test. Three roots with four canals (3R4C) were predominantly observed in the MFM's (85.6%) and three roots with three canals (3R3C) identified in 51.95% were more common than 3R4C (43.55%) in MSM's. Both the maxillary molars bilaterally, exhibited a high percentage of symmetry in root and canal configurations. Identification of root canal morphology of molars would reduce the chances of root canal failures by making sure all canals are obturated. This study provides supplemental information about the root canals of maxillary molars in a Saudi Arabian subpopulation.

Morphological Study of Root Canals of Maxillary Molars by Cone-Beam Computed Tomography.

The aim of this study was to evaluate the root canal morphology of permanent maxillary molars by cone-beam computed tomography (CBCT) using the classifications of Weine et al. and Vertucci and to correlate the findings with sex, age, position in the dental arch, and prevalence of a second canal in the mesiobuccal root (MB2). A total of 414 scans were evaluated, corresponding to 1,000 teeth. The assessment consisted of coronal, axial, and sagittal reconstructions using i-CAT Workstation®. Type 0 was assigned when neither classification could be applied. The data were entered into an Excel spreadsheet and analyzed using SPSS. The chi-squared test or Fisher's exact test was used to compare the distribution of root canal morphology classified using the two systems. Analysis of the distribution of Weine types showed a predominance of type III in mesiobuccal roots, while type 0 predominated in distobuccal and palatal roots. Vertucci type IV predominated in mesiobuccal and distobuccal roots and type VII in palatal roots. There was no difference in the distribution of morphological canal types in permanent maxillary molars evaluated by CBCT according to sex, age group, or position in the dental arch of the patients. MB2 canals were identified in 68.4% of the teeth evaluated.

Retreatment Of Root Canals In Maxillary Molars Due To Missing Second Mesiobuccal Canals And Its Association With Gender

Retreatment Of Root Canals In Maxillary Molars Due To Missing Second Mesiobuccal Canals And Its Association With Gender

Analysis of Root Canal Curvature and Root Canal Morphology of Maxillary Posterior Teeth in Guizhou, China.

BackgroundWe investigated the root canal curvature and morphology of maxillary posterior teeth in Guizhou, China, to provide references for clinical practice.Material/MethodsWe collected 274 maxillary posterior teeth in Guizhou Province, China. The root canal curvature was observed by X-ray film measurement. Two hundred teeth were selected to make transparent tooth models, and root canal configuration was recorded according to Vertucci classification criteria. The position of the MB2 root canal orifice and the mesiobuccal root canal configuration were observed by micro-computed tomographic (micro-CT) scanning. The t test and the chi-square test were used for statistical analysis.ResultsThe root canals of the maxillary posterior teeth showed more significant curvature in the mesiodistal direction than in the buccolingual direction (P<0.05). The MB2 root canal of maxillary molars showed severe bending in the mesiodistal direction: 25.16±6.6 degrees and 28.05±8.65 degrees in first and second molars, respectively. The detection rate of MB2 was 48% in maxillary first molars and 32% in maxillary second molars. The results of micro-CT showed that the vertical distances between the MB2 and MB-P line were 0.64±0.34 mm and 0.57±0.28 mm in first and second molars, respectively.ConclusionsThe root canal morphology and curvature of maxillary posterior teeth varied greatly in the Guizhou population, which increases the difficulty of treatment. It is necessary for clinicians to gain understanding of the root canal and to improve the success rate of root canal therapy.

Safety of large preparation with different instruments in the buccal canals of maxillary molars.

This study aimed to evaluate the influence of large apical preparations with Reciproc (REC), Hyflex CM (HCM) and Twisted File Adaptive (TFA) systems using micro-computed tomography (MCT). Ninety mesiobuccal (MB) and distobuccal (DB) root canals of maxillary molars (n=45) were scanned using MCT before and after the shaping procedures. The root canals (n=15) were prepared until REC 40.06, HCM 40.04 and TFA 35.04. The root canal transportation (RCT), centring ability (CA), change in volume of the root canal and at different levels (VC), remaining dentine thickness (RDT), removal of dentine wall (RDW) and working time (WT) were evaluated. Data were analysed using the Kruskal-Wallis and Dunn tests, and the one-way ANOVA and Tukey tests with a level of significance set at 5%. No significant difference among the instruments was found regarding the RCT, CA, RDT, RDW and WT (P>0.05), in larger apical preparations in curved MB and straight DB canals of maxillary molars.

A cone-beam computed tomography study of the prevalence and location of the second mesiobuccal root canal in maxillary molars.

ObjectivesThis study aimed to investigate the incidence and location of the second mesiobuccal root (MB2) canal in maxillary molars with the aid of various measuring points and lines using cone-beam computed tomography (CT).Materials and MethodsA total of 205 images of patients who underwent cone-beam CT examinations between 2011 and 2015 as part of their dental diagnosis and treatment were included. There were 76 images of the maxillary first molar and 135 images of the maxillary second molar. Canal orifices were detected at −1 mm from the top of the pulpal floor on cone-beam CT images. Image assessment was performed by 2 observers in reformatted image planes using software. Assessments included measurement of the distance between the MB1 and MB2 canals, and the angles between the lines connecting the MB1-MB2 and distobuccal (DB)-palatal (P) canals. The data were analyzed using the student's t-test.ResultsThe prevalence of the MB2 canal was 86.8% in the first molar and 28.9% in the second molar. The angle between the lines connecting the MB1-MB2 and DB-P canals was 2.3° ± 5.7° in the first molar and −3.95° ± 7.73° in the second molar. The distance between the MB1 and MB2 canals was 2.1 ± 0.44 mm in the first molar and 1.98 ± 0.42 mm in the second molar.ConclusionsThe angles between the lines connecting the MB1-MB2 and DB-P canals was almost parallel. These findings may aid in the prediction of the location of the MB2 canal orifice.

Incidence Of Accessory Canals In Maxillary Molars Under 25 Years Of Age And Its Association With Gender

The field of medicine is an ever changing science undergoing continuing tremendous development. A better understanding of art and science of endodontics have accelerated the introduction of various treatment modalities that has made the field flourish in the aspect of prognosis of different dental problems. Root canal treatment on a global basis has reported to be increasing as well, hence in this current scenario it is important for the clinician to have a thorough knowledge regarding the root canal anatomy and morphology for a successful treatment outcome. In this study we have attempted to assess and understand the influence of accessory canals in maxillary molars under 25 years of age and its influence on gender. The study was carried out in a university setting where the patient records were reviewed and analysed and a data of 86000 patients between June 2019 and March 2020 was collected and compiled, reviewed, tabulated, and exported to the Statistical Product and Service Solutions (SPSS) software for statistical analysis. A statistically significant data was not obtained from the study, but the data has remarkable clinical significance. Within the limitations of the study it has been found that 8% of the total entries analysed were indicated with accessory canals and a future extensive research involving a larger data will help in the diagnosis and treatment planning for the root canal of maxillary molars.

Evaluation of Quality and Preparation Time of Retrograde Cavities in Root Canals Filled with GuttaCore and Cold Lateral Condensation Technique

IntroductionThe aim of this study was to measure the time consumed preparing retrograde cavities in root canals of maxillary molars filled using the GuttaCore (Dentsply Tulsa Dental Specialties, Tulsa, OK) technique and the cold lateral condensation technique (CLC) and to examine the quality of the root-end cavity preparation by ultrasonic tips using micro–computed tomographic (micro-CT) scanning. MethodsA total of 24 maxillary molars were included; distobuccal and palatal canals were instrumented to size #40 and size #50, respectively. Teeth were randomly distributed into 2 experimental groups; half of the samples were filled with CLC, and half were filled with the GuttaCore technique. After 2 months, the apical 3 mm of each root apex was resected. A retrograde cavity was then prepared 3 mm deep into the root-end–filled canals using ultrasonic tips. The quality of the preparation was first confirmed by a surgical stereomicroscope, and the time required for the root-end preparation was recorded. After root-end cavity preparation, all samples were scanned by micro-CT scanning. ResultsThere was no significant difference between the palatal and distobuccal canals in the time required to prepare a retrograde cavity. Less time was required in the GuttaCore group to remove all root filling material and finish the cavity preparation than in the CLC group (P < .05), especially in the palatal canals. Micro-CT results confirmed that all material was removed from the root-end cavities and the absence of microcracks. ConclusionsGuttaCore was removed in less time from root-end cavities than root filling performed with the CLC technique. No damage to the surrounding dentin was detected by micro-CT scanning in the 2 groups.

Prevalence of technical errors and periapical lesions in a sample of endodontically treated teeth: a CBCT analysis.

The aims of this study are to identify the most frequent technical errors in endodontically treated teeth and to determine which root canals were most often associated with those errors, as well as to relate endodontic technical errors and the presence of coronal restorations with periapical status by means of cone-beam computed tomography images. Six hundred eighteen endodontically treated teeth (1146 root canals) were evaluated for the quality of their endodontic treatment and for the presence of coronal restorations and periapical lesions. Each root canal was classified according to dental groups, and the endodontic technical errors were recorded. Chi-square's test and descriptive analyses were performed. Six hundred eighty root canals (59.3%) had periapical lesions. Maxillary molars and anterior teeth showed higher prevalence of periapical lesions (p < 0.05). Endodontic treatment quality and coronal restoration were associated with periapical status (p < 0.05). Underfilling was the most frequent technical error in all root canals, except for the second mesiobuccal root canal of maxillary molars and the distobuccal root canal of mandibular molars, which were non-filled in 78.4 and 30% of the cases, respectively. There is a high prevalence of apical radiolucencies, which increased in the presence of poor coronal restorations, endodontic technical errors, and when both conditions were concomitant. Underfilling was the most frequent technical error, followed by non-homogeneous and non-filled canals. Evaluation of endodontic treatment quality that considers every single root canal aims on warning dental practitioners of the prevalence of technical errors that could be avoided with careful treatment planning and execution.

Does adding an instrument after root preparation with Reciproc® R25 increase bacterial reduction?

Aim:The aim of this study was to compare the bacterial reduction achieved with reciprocating instruments such as Reciproc® R25 (VDW GMBH, Munich, Germany) and Reciproc® R25 combined with rotary file Mtwo 40.04 (VDW GMBH) during root canal preparation.Materials and Methods:Fifty mesiobuccal root canals of maxillary molars were contaminated with Enterococcus faecalis broth culture and then an initial bacterial sample was collected from the root canal with paper cones and plated on brain–heart infusion agar. The root canals were divided into four groups as follows: Reciproc® R25 (n = 20) and Reciproc® R25 combined with Mtwo 40.04 instrument (n = 20). The negative controls consisted of five uncontaminated root canals and the positive control consisted of five contaminated roots that were not subjected to any decontamination procedure. Irrigation was performed using sodium chloride. After instrumentation, samples were collected with paper cones and the rate of bacterial reduction was calculated. Microbiological testing (colony-forming units [CFUs]) was performed to quantify the decontamination obtained by the proposed protocols. Statistical analysis was performed by paired t-test and analysis of variance test.Results:Both techniques significantly reduced the number of bacteria in the root canal (P < 0.05), with no significant difference among them (P > 0.05).Conclusion:The addition of the instrument Mtwo 40.04 after the root preparation with the instrument R25 does not improve its decontamination capability.

Instrument Design May Influence Bacterial Reduction During Root Canal Preparation.

The aim of this study was to evaluate the bacterial reduction promoted by ProTaper Next and Twisted File by comparing to ProTaper Universal and manual technique. Sixty distobuccal root canals of maxillary molars sterilized with ethylene oxide were contaminated with Enterococcus faecalis broth culture. After incubation for 21 days, bacterial samples were collected and cultured on m-Enterococcus agar plates. The root canals were divided into 4 groups, according to the system used for instrumentation: ProTaper Next, Twisted File, ProTaper Universal, and crown down manual technique. Other 8 uncontaminated root canals were control asepsis. Bacterial samples were collected immediately and 7 days after instrumentation. The bacterial reduction was calculated and then made intragroup analysis by paired t-test and intergroup analysis by ANOVA and Tukey tests, all at 5% significance. All techniques significantly reduced the bacterial number in the root canal (p<0.05). ProTaper Next and Twisted File resulted in more bacterial reduction than ProTaper Universal and manual technique (p<0.05). ProTaper Next and Twisted File were similar (p>0.05). It can be concluded that ProTaper Next and Twisted File promote a higher bacterial reduction than Protaper Universal and manual technique.

The ability of Reciproc instruments to reach full working length without glide path preparation: a clinical retrospective study.

BackgroundReciproc instruments are the only contemporary root canal instruments where glide path preparation is no longer strictly demanded by the manufacturer. As the complete preparation of root canals is associated with success in endodontic treatment we wanted to assess the ability and find predictors for Reciproc instruments to reach full working length (RFWL) in root canals of maxillary molars in primary root canal treatment (1°RCTx) and retreatment (2°RCTx) cases.MethodsThis retrospective study evaluated 255 endodontic treatment cases of maxillary molars. 180 were 1°RCTx and 75 2°RCTx. All root canals were prepared with Reciproc instruments. The groups were compared and in a binary logistic regression model predictors for RFWL were evaluated.ResultsA total of 926 root canals were treated with Reciproc without glide path preparation. This was possible in 885 canals (95.6%). In 1°RCTx cases 625 of 649 (96.3%) canals were RFWL and in 2°RCTx cases 260 of 277 (93.9%). In second and third mesiobuccal canals (MB2/3) 90 out of 101 (89.1%) were RFWL with Reciproc in 1°RCTx and in the 2°RCTx treatment group 49 out of 51 cases (96.1%). In mesio-buccal (MB1) canals “2°RCTx” was identified as negative predictor for RFWL (OR 0.24 (CI [0.08–0.77])). In MB2/3 canals full working length was reached less often (OR 0.04 (CI [0.01–0.31])) if the tooth was constricted and more often if MB2/3 and MB1 canals were convergent (OR 4.60 (CI [1.07–19.61])).DiscussionUsing Reciproc instruments, the vast majority of root canals in primary treatment and retreatment cases can be prepared without glide path preparation.

Shaping Ability of Single-file Systems with Different Movements: A Micro-computed Tomographic Study.

Introduction:This study aimed to perform a rigorous sample standardization and also evaluate the preparation of mesiobuccal (MB) root canals of maxillary molars with severe curvatures using two single-file engine-driven systems (WaveOne with reciprocating motion and OneShape with rotary movement), using micro-computed tomography (micro-CT). Methods and Materials:Ten MB roots with single canals were included, uniformly distributed into two groups (n=5). The samples were prepared with a WaveOne or OneShape files. The shaping ability and amount of canal transportation were assessed by a comparison of the pre- and post-instrumentation micro-CT scans. The Kolmogorov-Smirnov and t-tests were used for statistical analysis. The level of significance was set at 0.05. Results:Instrumentation of canals increased their surface area and volume. Canal transportation occurred in coronal, middle and apical thirds and no statistical difference was observed between the two systems (P>0.05). In apical third, significant differences were found between groups in canal roundness (in 3 mm level) and perimeter (in 3 and 4 mm levels) (P<0.05). Conclusion:The WaveOne and One Shape single-file systems were able to shape curved root canals, producing minor changes in the canal curvature.

Analysis of C-shaped root canal configuration in maxillary molars in a Korean population using cone-beam computed tomography.

ObjectivesThe purpose of this study was to investigate the incidence of root fusion and C-shaped root canals in maxillary molars, and to classify the types of C-shaped canal by analyzing cone-beam computed tomography (CBCT) in a Korean population.Materials and MethodsDigitized CBCT images from 911 subjects were obtained in Chosun University Dental Hospital between February 2010 and July 2012 for orthodontic treatment. Among them, a total of selected 3,553 data of maxillary molars were analyzed retrospectively. Tomography sections in the axial, coronal, and sagittal planes were displayed by PiViewstar and Rapidia MPR software (Infinitt Co.). The incidence and types of root fusion and C-shaped root canals were evaluated and the incidence between the first and the second molar was compared using Chi-square test.ResultsRoot fusion was present in 3.2% of the first molars and 19.5% of the second molars, and fusion of mesiobuccal and palatal root was dominant. C-shaped root canals were present in 0.8% of the first molars and 2.7% of the second molars. The frequency of root fusion and C-shaped canal was significantly higher in the second molar than the first molar (p < 0.001).ConclusionsIn a Korean population, maxillary molars showed total 11.3% of root fusion and 1.8% of C-shaped root canals. Furthermore, root fusion and C-shaped root canals were seen more frequently in the maxillary second molars.

A cone-beam computed tomographic study of C-shaped root and root canal in maxillary molars

Purpose: The aim of this retrospective study was to investigate the prevalence rate and types of C-shaped roots and C-shaped canal in maxillary molars by analyzing cone-beam computed tomography (CBCT) in a Korean population. Materials and Methods: Total of 357 CBCT images of maxillary molars (186 first molar, 171 second molar) were evaluated by two Endodontic specialists. Results: Eight types of C-shaped roots and 5 types of C-shaped canals were founded, the prevalence rate of C-shaped roots and canals were 21.0% and 5.3% respectively. Conclusion: These anatomical variations were more frequent in second molars than the first molars. Clinicians should have anatomical knowledge about various types of C-shaped root and root canal for successful root canal therapy.