Roots Of Molar Teeth Research Articles

A Computed Tomographic Study of the Molar Teeth of Babyrousa spp.

A photographic and computed tomography (CT) scanning study was carried out on 295 molar teeth of 18 adult male Babyrousa babyrussa skulls and 8 skulls of Babyrousa celebensis including seven adult males and one adult female. The occlusal morphology of the permanent maxillary and mandibular molar teeth of B. babyrussa was very similar to that of B. celebensis. Most B. babyrussa maxillary molar teeth had six roots, with small numbers of teeth having four, five or seven roots. A similar pattern was suggested in B. celebensis. Mandibular molar teeth had between four and eight roots. Tooth roots of maxillary and mandibular first and second molar teeth were largely tapering, rod-like structures. The roots of the right and left maxillary third molar teeth had a more complex arrangement; some were inserted almost vertically into the maxilla; others were orientated in a more distal direction. The mesial and distal roots were splayed in appearance. The right and left mandibular third molar tooth roots retained elements of the open 'C' shape and were generally orientated distally. The pulp chambers were arched to fit under the main cusps in all molar teeth. Pulp canals were variable in number.

Antibacterial Behavior of Silver Diamine Fluoride, Sodium Hypochlorite and Ozone Gel on Enterococcus faecalis in Root Canal of Deciduous Teeth

Introduction: Enterococcus faecalis (E. faecalis) has been reported as one of the most important causes of failed endodontic treatments. Various antibacterial agents have been suggested to remove E. faecalis from the root canal. We aimed to investigate and compare the antibacterial efficacy of silver diamine fluoride (SDF), Sodium hypochlorite (NaOCl) and ozone gel on E. faecalis in the root canal. Materials and Methods: This study involved 60 extracted roots of molar teeth with a single root canal to generate a 6-week-old biofilm for evaluating antibacterial effects. After teeth decorating and removing the smear layer using sodium hypochlorite (2.5%) and EDTA (17%), roots were sterilized by autoclave. Under sterile conditions, 1 ml of the suspension containing E. faecalis bacteria was transferred to each of the microtubes containing teeth. The samples were divided into four groups: exposed to NaOCl (2.5%) as a positive control, exposed to liquid ozone (25 ppm), exposed to SDF (3.8%), and exposed to normal saline as a negative control group. Then, the colony forming unit (CFU) was counted in the studied groups. Kruskal-Wallis test and Dunn-Bonferroni post-hoc analysis were carried out for comparison of CFU in the studied groups. Results: The mean of CFU were 17846, 920, 234, and 336 for saline, ozone, NaOCl, and SDF, respectively. There were significant differences in CFU in the comparison of (NaOCl-Ozone), (NaOCl-saline), (SDF-saline), and (ozone-saline) (P< 0.05). However, there was no significant difference for CFU in the comparison of NaOCl-SDF (P= 0.570). Conclusion: The study findings showed that NaOCl (2.5%) and SDF (3.8%) were more effective against the 6-week-old E. faecalis biofilms than ozone and saline.

Evaluation of The Accuracy of Two Apex Locators For Determining The Working Length of Endodontically Retreated Curved Mesial Roots of Maxillary Molar Teeth : An Ex Vivo Study

Objective: To evaluate the accuracy of PROPEX PİXİ (Dentsply Sirona, Ballaigues, Switzerland) and Apex ID (Sybron Endo, Orange, CA, USA) in determining the working lengths of curved mesial roots of upper molars during the retreatment procedure. Method: Twenty curved mesial roots of upper molar teeth were selected. Canals were shaped with ProTaper Next instruments (Dentsply Sirona) up to X3. The canal lengths were determined with a microscope (Carl Zeiss GmbH, Oberkochen, Germany) at 2,5X magnification (DM) and then also detected electronically (EM1P and EM1A) with PROPEX PİXİ (Dentsply Sirona) and Apex ID (Sybron Endo) in an alginate model. Specimens were then obturated using a size X3 master gutta-percha cone and an epoxy resin-based root canal sealer. Seven days later, the coronal part of the filling was removed with a Gates Glidden drill size 3 and for the middle part Protaper Universal Retreatment File D2 used. Working lengths electronically were detected again by two different apex locaters (EM2P and EM2A). Data were analysed by using the Wilcoxon Signed Rank and Mann Whitney u test. The analyses were carried out with MedCalc Statistical Software. Results: No significant difference was found between direct measurements (DM) and electronic measurements before and during retreatment for PROPEX PİXİ (P=0.135) and Apex ID (P=0.232). Also there was no significant difference between two apex locaters before (P=0.108) and during retreatment (P=0.242) Conclusion: PROPEX PİXİ and Apex ID were considered accurate for the root canal length determination during retreatment procedure. Keywords: Apex locator, curved molar, retreatment, working lenght

Evaluation of the efficacy of rotary and reciprocating systems for the removal of filling material for various root canal filling techniques.

This study aimed to evaluate the efficacy of various filling and retreatment techniques for oval-shaped root canals. Sixty distal roots of mandibular molar teeth were included in the study. The roots were prepared using the ProTaper Next (PTN) X4 rotary system and irrigation with 2.5% NaOCl. The roots were then divided into three groups and filled with Total Fill BC Sealer (FKG Dentaire) using three different techniques (n=20): single cone (SC), GuttaCore (GC), and warm vertical condensation (WVC). The retreatment procedure was performed using two different instrumentation techniques: Reciproc 50 (R50) and PTN X5 (n=10). To analyze the remaining filling material, the roots were divided buccolingually in two parts with the help of diamond separators, and photographs were taken at x16 magnification using a dental operating microscope (DOM). The ratio of the remaining filling materials was calculated using image analysis software and statistically evaluated using the Kruskal-Wallis test. None of the assessed retreatment procedures completely removed the filling materials from the root canals. For both instrumentation techniques, more root canal filling material remained in the WVC group (P<0.05). The GC filling technique had a higher cleaning percentage than the WVC and SC techniques in the coronal region. The R50 system was found to be superior to the PTN X5 system for retreatment, and the root canal fillings applied using the WVC technique were more difficult to remove than the fillings applied using the other techniques.

Investigation of the effectiveness of sonic, ultrasonic and new laser-assisted irrigation activation methods on smear removal and tubular penetration.

The aim of this study was to examine the effectiveness of different irrigation activation methods on smear layer removal and tubular penetration. One hundred-five distal roots of mandibular molar teeth in total; 50 for smear removal efficiency (n = 10) analysis using scanning electron microscopy (SEM), and 55 roots were used to examine tubular penetration using confocal laser scanning microscope (CLSM). Five different irrigation activation methods were used in this study; conventional needle irrigation (CNI), sonic irrigation device of EDDY, passive ultrasonic irrigation (PUI), PIPS and SWEEPS techniques, which are two different laser irrigation activation methods. The obtained data were statistically analyzed and the significance level was determined as p < 0.05. At the apical level, the cleanest canal walls were observed when laser methods PIPS and SWEEPS were used, while in the middle third, there was no difference in smear removal efficiencies between all groups except for the CNI (p > 0.05). Penetration depths and percentages increased from apically to coronally in all groups. The PUI and EDDY generally showed similar penetration depths and percentages to the CNI, except at the coronal root level (p > 0.05). In all groups, when PIPS was used, it showed greater penetration depth and percentage (p < 0.05). PIPS and SWEEPS techniques showed lowest and similar smear scores compared to PUI and EDDY in the apical area where access and effectiveness of the irrigation solution are difficult.

Evaluation of trabecular bone in individuals with periodontitis using fractal analysis: An observational cross-sectional study.

It is very difficult to objectively evaluate the negative changes in bone structure due to periodontitis. The present study was aimed to evaluate the trabecular bone structure between healthy individuals and periodontitis patients by fractal analysis (FA) on digital panoramic radiographs. The study included 50 periodontally healthy individuals (control group), 50 individuals with Stage 1 periodontitis (S1-P group), 50 individuals with Stage 2 periodontitis (S2-P), and 50 individuals with Stage 3 periodontitis (S3-P), a total of 200 individuals were included. The fractal dimension (FD) value of the trabecular bone in the interdental space between mandibular first molar and second premolar tooth roots was evaluated using Image J program. The mean FD values of the two regions were calculated by box counting method. There was a statistically significant difference between the groups in terms of all periodontal parameter values (p<0.05). The mean FD values of individuals diagnosed with periodontitis were 1.36±0.08 in the S1-P group, 1.35±0.07 in the S2-P group, 1.28±0.15 in the S3-P group, and 1.44±0.06 in the control group. When the FD values between the groups were examined, it was seen that there was a statistically significant difference between the control and individuals with periodontitis, and the mean FD values were significantly higher in the healthy group (p<0.05). The best receiver operator curve was identified for periodontitis at the ≤1.409 cut-off FD value (area under the curve: 0.828; 95% CI: 0.758-0.899); p=0.000, p<0.001). FD evaluation can give an objective result about the effect of periodontitis on alveolar bone. The FD values of trabecular bone are different in healthy individuals and individuals with different stages of periodontitis. The findings suggested that a negative correlation between the periodontal data with the sites in which FD was measured and as the periodontitis stage progresses, FD decreases. Key words:Diagnosis, Periodontal Diseases, Radiographic Evaluation.

Evaluation of the Ability of Panoramic Radiography in the Determining the Morphology and Position of third Molar Roots

Introduction: Most third molars eventually need to be extracted, and this tooth has the most varied and unpredictable root position of all teeth. Therefore, considering the importance of accurate diagnosis of the roots of molar teeth before surgery to reduce its surgical complications, the aim of this study was to evaluate the ability of panoramic radiography to diagnose the situation of roots of third molars. the relationship of the roots to each other and the angle of the crown to the root in panoramic and clinical radiographs, respectively, using Romexis viewer and digimizer software were investigated.&#x0D; Methods: In this cross-sectional-analytical study, 104 third molars of 93 patients referred for wisdom tooth extraction were examined clinically for the number of roots, the relationship of roots to each other and the angle of the crown to the root in panoramic radiography using Romexis Viewer software and clinically after providing photograph and measuring the angle using digimizer software.&#x0D; Results: In evaluating the roots of third molars, the accuracy of panoramic radiographic interpretation regarding the number of roots was 63.27% and in the presence or absence of root, adhesion was 55.89%. In addition, Pearson correlation analysis showed that there was a significant relationship between the reported angle in radiographic interpretation and the actual angle (r = 0.318 and P value = 0.001).&#x0D; Conclusion: Therefore, panoramic radiography is a valuable guide for third molar surgery. It is only necessary to consider its high error rate in terms of morphological details such as the number of roots and their relationship to each other.

The anatomical relationship between the mandibular first molar roots and the mandibular canal based on breed size and skull type.

The first molar is the largest tooth in the dog mandible with roots often extending to the level of the mandibular canal (MC). The anatomical relationship between the roots and MC is variable and the normal relationship between those structures in a diverse population of dogs has not been established. The lingual location of the roots relative to the MC poses a risk for iatrogenic trauma during dentoalveolar surgery, and it is unknown if certain skull conformations are predisposed to this relationship. This study aimed to identify associations between patient weight and skull type with molar tooth root location. CT scans performed for reasons unrelated to the study were retrospectively analyzed. Subjects were sorted into one of 12 groups (n=16 per group) based on skull type (brachycephalic, mesaticephalic, and dolichocephalic) and weight (extra small: ≤ 6.8 kg, small: >6.8 to ≤ 13.6 kg, medium: >13.6 to ≤ 25 kg, and large >25 to ≤ 38.6 kg). The mandibular first molar roots were categorized as lingual, buccal, or dorsal relative to the MC. Lingual root location was diagnosed in 50.0% of all roots evaluated, and 64.2% of all dogs assessed had at least one root in the lingual position. The size was shown to be protective, with lingual root location being significantly less likely as size increased. The exception to this was in large brachycephalic patients, which had rates of lingual roots similar to smaller dogs. Buccal roots were rarest, diagnosed in only 9.7% of all roots, and were most common in brachycephalic patients, which had 83.8% of all buccal roots. Additional caution should be employed when removing alveolar bone during surgical extraction in dogs ≤ 13.6 kg and in large brachycephalic patients (boxers) to avoid iatrogenic trauma to the neurovascular bundle.

The Effect of Varying Occlusal Loading Conditions on Stress Distribution in Roots of Sound and Instrumented Molar Teeth: A Finite Element Analysis

IntroductionThis study aimed to investigate whether the direction of force applied to the occlusal surface influenced the pattern of tensile stresses in roots of sound and root canal–prepared mandibular molar teeth. The effect of obturation forces on the development of apical stress was also investigated. To this end, models were constructed using micro–computed tomographic imaging and investigated using finite element analysis. MethodsMicro–computed tomographic data established boundaries of internal and external model surfaces to allow finite element analysis. Individually segmented components were modeled based on mechanical properties in precedent literature. The following conditions were considered: axial force directed over the mesial marginal ridge, a mesial or a distal tipping force, a combination of both a torquing force and axial loading, and hydrostatic pressure. The maximum principal stresses were determined. ResultsThe highest root stress occurred in the cervical third of root surfaces (ie, not apically) under all loading conditions. Importantly, mesial tipping forces resulted in tension on distal roots, whereas distal tipping resulted in tension in the mesial roots. Intracanal pressures produced tensile stress on the internal root canal walls in the cervical third of the root. Stresses were calculated to be less than the fatigue tensile strength of dentin. ConclusionsStatic loading, under the conditions modeled, does not result in stress concentration at the root apices that would cause root fracture under normal masticatory loads. Stress patterns developing from mesial and distal tipping forces help to explain the appearance of vertical root fractures reported in sound nonrestored molar teeth.

The Effect of Rotation Speed of XP-endo Shaper on Apically Extruded Debris During Endodontic Procedures: an In Vitro Study

The aim of this study was to evaluate the effect of using a higher rotation speed with the XP-endo Shaper (XPS) on apically extruded debris and operation time during endodontic treatment and retreatment procedures. Sixty mesial roots of mandibular first molar teeth were randomly assigned to four groups (Initial treatment groups: XPS used at 1000 or 3000rpm rotation speeds and Retreatment groups: XPS used at 1000 or 3000rpm rotation speeds). During the initial treatment and retreatment procedures preweighed eppendorf tubes were used to collect apically extruded debris, and the operation time was recorded in seconds. The extruded debris was quantified by subtracting the preinstrumentation from the postinstrumentation weight of the Eppendorf tubes. Data were analysed using two-way ANOVA at a significance level of 0.05. In all groups, the use of the XPS at 1000 or 3000rpm rotation speeds had no statistically significant effect on the amount of apically extruded debris (p&gt;0.05). The use of the XPS at a 3000rpm rotation speed significantly decreased the instrumentation time (p&lt;0.05). In summary, the use of the XPS at high rotation speeds in initial treatment and retreatment procedures did not have a significant effect on the amount of apically extruded debris but significantly decreased the operation time.

Does the extent of cortical perforation of the inferior alveolar nerve canal by the roots of third molar teeth seen on cone beam computed tomography predict postoperative paraesthesia? - A prospective clinical study

The aim of this study was to assess the extent of cortical perforation in millimetres (mm) in inferior alveolar nerve (IAN) canal on coronal section of cone beam computed tomography (CBCT) to predict IAN injury in high risk patients. We also analysed relation of position of canal and number of roots with likelihood injury to IAN. We conducted a prospective clinical study of 100 high risk patients in which 78 patients had cortical perforation which was verified by CBCT. 13/78 of 3rd molars were associated with IAN injury at 1 month post extraction. Out of those, only 3 had a permanent decrease in sensation and remaining 10 had temporary paraesthesia. Owing to the large number of patients with cortical defects, we further sub-categorised them into five groups based on cortical perforation: Type 1 – No involvement, Type 2–1 - 3 mm, Type 3–4 - 6 mm, Type 4–7 - 9 mm, Type 5 – more than 9 mm. All of the 8 patients who had more than 6 mm (Type 4 and Type 5) had some sensory disturbance whereas no IAN injury was found in patients of type 1 and type 2. There were 5/23 who had nerve injury in type 3. The association between cortical perforation and IAN injury was statistically significant (p - <0.0001). Extent of cortical perforation can be a reliable predictor to predicate IAN injury prior to lower third molar extraction. In addition, the presence of abnormal sensation was significantly associated with different canal positions (p - <0.0001) whereas association of number of roots and IAN injury was statistically insignificant (p - 0.3112).

CBCT comparison of buccal shelf bone thickness in adult Dravidian population at various sites, depths and angulation – A retrospective study

It is important to understand the variations in the bone thickness of the buccal shelf region among different ethnic groups, as these variations will influence the placement and success of the buccal shelf mini-screw. The primary objective was to analyse the total buccal bone and cortical bone thickness of the mandibular buccal shelf region (MBS) at various depths, mesiodistal positions and angulations in Dravidian population and to find the best site for insertion of buccal shelf mini-implant. This was a retrospective study done on 30 cone-beam computed tomography samples collected from 30 subjects, aged 16 to 25 years and of Dravidian origin, who reported for orthodontic treatment. The total bone and cortical bone thicknesses of the buccal shelf regions were evaluated in relation to the Disto-Buccal cusp of 1st Molar (DB1M), Mesio-Buccal cusp of 1st Molar (MB1M), and Disto-Buccal cusp of 2nd Molar (DB2M) at the depths of 4mm, 8mm and 12mm from cemento-enamel junction (CEJ). The total bone thickness and the clearance from the root and cortical bone thickness were assessed at angulations of 30, 45 and 60 degrees from 5mm below the root apex. ANOVA and Post Hoc tests were done to compare the bone thickness measurements. Kappa statistics was done to assess the intraobserver reliability. Pearson's correlation test was done to find the correlation between growth pattern and thickness of the bone. The mean age group of the included sample was 20.5 years. Maximum total bone thickness was observed at a depth of 8mm in relation to the MB2M (6.41±0.29mm) and 12mm in relation to the DB2M 6.56±0.28mm and the P value was 0.000. Maximum bone thickness was present in the DB2M at 30° followed by DB2M 45° of 11.42±0.35mm and 10.89±0.3mm and the P value was 0.000. The maximum clearance from the root was observed at 30° and 45° in the DB2M with 5.35±0.2mm and 5.18±0.27mm, the P value was 0.014 when comparing angulation 30 and 45°. The DB2M had a cortical bone thickness of 2.97±0.15mm and 2.8±0.2mm at 45° and 60° and was statistically significant. The insertion site with optimal bone quantity was observed in relation to the buccal aspect of distobuccal cusp of 2nd molar at depth of 8mm or greater with a preferred angulation of 30-45° to have adequate clearance from the molar tooth roots and to penetrate a region of cortical bone of minimum 2mm.

GLANDULAR ODONTOGENIC CYST OR LOW-GRADE MUCOEPIDERMOID CARCINOMA? A CASE CHARACTERIZED WITH OVERLAPPING HISTOMORPHOLOGICAL FINDINGS

Background Glandular odontogenic cyst (GOC) is a rare odontogenic epithelial cyst of the jaw, with glandular differentiation. It occurs in adults and mostly in the anterior mandible. Case A 38-year-old female patient underwent curettage because of a well-circumscribed 15 × 10 mm cystic lesion, associated with the molar tooth root, in the mandible. Histopathologic examination revealed a neoplastic cystic lesion containing distorted small glands that seemed smaller in size around the cyst lined by mucinous columnar epithelium. In rare areas, immature metaplastic squamous epithelial islands in relation to the wall of the cyst was striking. There were often goblet cells within the cyst lining. No significant nuclear atypia was detected in the epithelium. Very rarely, typical mitoses were observed. Free mucin ponds were commonly observed in the cyst lumen, stroma. PanCK stain highlighted much smaller glands in areas around the cyst, as well as small clusters of epithelial cells in abortive, distorted character and even without gland structure. No significant staining was detected with P53 and Ki67. The case was considered to be compatible with GOC due to lack of nuclear atypia, low mitotic and Ki67 index, and no evidence of destructive invasion. However, because low-grade mucoepidermoid carcinoma could not be excluded, follow-up was recommended. Conclusions GOC has histomorphological findings overlapping with those of low-grade mucoepidermoid carcinoma. The absence of nuclear atypia, mitotic activity, and invasion findings is important in the diagnosis of GOC, but LGMECs that have weak criteria for malignancy may cause serious problems in differentiation from GOCs in some cases.

Localization of the First Mandibular Molar Roots in Relationship to the Mandibular Canal in Small Breed Dogs-A Tomography Imaging Study.

The intimate relationship between the mandibular canal (MC) and the first mandibular molar tooth presents challenges when performing dentoalveolar surgical procedures due to the probability of causing iatrogenic injury to the inferior alveolar neurovascular bundle. Superimposition between the MC and the first molar (M1) tooth roots is often observed on intraoral dental radiographs in small breed dogs. However, due to the radiograph's bidimensional nature, it is impossible to determine the buccal or lingual localization of the first molar roots with respect to the MC. Thus, this study's objective was to determine the localization of the first molar tooth's roots in relation to the position of the MC and their overlapping percentage with the canal in small-bodyweight dogs (<15 kg) using tomographic diagnostic images. For this, cone-beam computed tomography and high-definition computed tomography exams from 103 small breed dogs (under 15 kg) were retrospectively assessed to determine the lingual or buccal localization of the first molar tooth's roots with respect to the MC and the degree of overlap of the roots with the canal. In conclusion, most of the roots of M1 of dogs under 15 kg were located at the MC's lingual aspect (82.7%) with an overall superimposition median with the MC of 100 and 90% for the mesial and distal roots, respectively. Straddle tooth roots were not a common anatomical presentation in the dogs of this study.

Comparison of Sealing Ability of Bioceramic Sealer, AH Plus, and GuttaFlow in Conservatively Prepared Curved Root Canals Obturated with Single-Cone Technique: An In vitro Study.

Background:Inadequate obturation techniques of the root canal system have been found to be the most frequent reason of failure post root canal treatment. An ideal endodontic sealer should fulfill all ideal requisites. The present study aimed to compare apical sealing ability between bioceramic (BC) sealer, GuttaFlow, and AH Plus.Methodology:One hundred and twenty-five curved roots of maxillary and mandibular third molar teeth with fully formed apex were collected for this study. The root canals were cleaned and shaped using a standard single-cone preparation to file at the established working length and divided into five groups of 25 each. Dye leakage was carried out. Group A: with GP, using EndoSequence BC sealer with conventional with 4% gutta-percha (Brasseler USA, Savannah, Georgia, USA); Group B: with ceramic coated with 4% gutta-percha (Brasseler USA, Savannah, Georgia, USA); Group C: with GP, using AH Plus sealer (Dentsply, De-Trey Konstanz, Germany) with 4% gutta-percha; Group D: with GuttaFlow bioseal (Roeko-Coltène/Whaledent, Langenau, Germany) with 4% Gutta-percha; and Group E is a negative control group. Statistical analysis was done using the Statistical Package for the Social Sciences software and Student's unpaired t-test.Results:The group AH Plus showed more leakage values than the GuttaFlow group and of two groups of BC sealer and negative control. Student's unpaired t-test disclosed no significant difference (P < 0.05) between the groups.Conclusion:None of the sealers used in the study could completely seal the apical foramen to have a fluid-tight seal.

Morphometric analysis of cleaning efficacy of ProTaper NEXT and Lightspeed LSX rotary system

Aim: The aim of the study was to evaluate the cleaning efficacy of ProTaper NEXT and Lightspeed LSX rotary system by morphometrical analysis. Material and Methods: Ten extracted mesial roots of human mandibular molar teeth were randomly assigned in two groups ProTaper NEXT (Group I) and Lightspeed LSX (Group II). 3 serial transverse cross sections (5μm) at apical third were prepared and histologically processed. The cross sections were examined under optic microscope 100x magnification. The images were submitted to morphometrical analysis using Motic® software to determine the percentage of root canal area with debris and were analyzed statistically using Wilcoxon Rank Signed Test and one-way analysis of variance (ANOVA). Results: Percentage debris in group I (ProTaper NEXT) was less compared to group II (Lightspeed LSX) (p

Using Expandable Micro-Motor Bur (EMB) forExtraction of Molar Tooth Root of Dog's UpperJaw

Extraction of a broken tooth root is often a traumatic involvement for both the specialist and the patient. To extract broken roots, generally, invasive approaches as open window surgeries or mucoperiosteal flap and/or removal of buccal bone are performed. Expandable micro-motor bur (EMB) is a practical dental instrument proposed for the removal of broken teeth roots that cannot be extracted by the routine closed methods. The device comprises a micro-motor, spacers, needles, bur base, and a round bur that drills halfway through the root canal, expands to make a spherical cavity around itself, and behaves as an efficient extraction aiding anchor. The utilization of EMB would introduce a new technique in the removal of broken teeth roots in which surgical trauma is minimized and so are post-extraction disorders. The use of EMB would also eliminate surgical invasion to the surrounding tissues, and it would eliminate profound hand forces by the practitioner, consequently reduces stress for both the practitioner and the patient. It would also eliminate high-risk aftermaths of the surgery such as operative morbidity (due to bone loss), maxillary sinus exposure, and probable need for additional surgery which are some of the implications of the conventional open access approaches. We have tested the prototype of EMB on the molar tooth root of a dog in his upper jaw (M1) in the Medical Sciences and Technologies Research Institute of Shahid Beheshti University. No injuries to the buccal bone and surrounding nerves were observed and the root was successfully extracted. Further studies are needed to confirm its effectiveness in clinical cases.

Quantitative Analysis of the Anatomy of Mesial Roots of Mandibular First Molars with Vertucci Type I Root Canal Configuration by Means of Micro-Computed Tomography

Aim: This study aimed to evaluate root canal morphology of Vertucci type I root canal configuration detected in mesial roots of mandibular first molar teeth using micro-computed tomography (Micro-CT).&#x0D; Methodology: Micro-CT datasets of 269 specimens were evaluated for the detection of specimens with Vertucci type I root canal configuration for further analysis. Major and minor diameter, area, perimeter and roundness of root canal cross-sections at the beginning and midline of each root thirds were measured and recorded. The presence of apical delta, accessory canals, and deviation of major apical foramen from anatomical apex were investigated. Data was analyzed using descriptive analysis, ANOVA-Tukey and Kruskal-Wallis H-Wilcoxon signed-rank tests.&#x0D; Results: Vertucci type I canal configuration was present in the 4.46% of the specimens. The specimens often showed accessory root canals (50%) and apical deltas (41,6%). From the visual analysis of the 3D and 2D images, significant differences were detected among coronal, middle and apical thirds of the specimens regarding major and minor diameter, area, perimeter and roundness (P &lt; 0.05).&#x0D; Conclusion: Three- and two-dimensional analyses of mesial roots with Vertucci type I canal configuration indicated that this type of configuration presents large buccolingual diameters with long oval shape and has isthmus at coronal and middle thirds. At the apical third the root canals often terminate in an oval cross sectional shape.&#x0D; &#x0D; How to cite this article: Keles A, Keskin C. Quantitative analysis of the anatomy of mesial roots of mandibular first molars with Vertucci type I root canal configuration by means of micro-computed tomography. Int Dent Res 2020;10(1):17-21. https://doi.org/10.5577/intdentres.2020.vol10.no1.4&#x0D; &#x0D; Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Comparison of Different Cervical Finish Lines of All-Ceramic Crowns on Primary Molars in Finite Element Analysis

This study aimed to conduct a stress analysis of four types of cervical finish lines in posterior all-ceramic crowns on the primary roots of molar teeth. Four different types of finish lines (shoulder 0.5 mm, feather-edged, chamfer 0.6 mm, and mini chamfer 0.4 mm) and two all-ceramic crown materials (zirconia and lithium disilicate) were used to construct eight finite element primary tooth models with full-coverage crowns. A load of 200 N was applied at two different loading angles (0° and 15°) so as to mimic children’s masticatory force and occlusal tendency. The maximum stress distribution from the three-dimensional finite element models was determined, and the main effect of each factor (loading type, material, and finish line types) was evaluated in terms of the stress values for all of the models. The results indicated that the loading type (90.25%) was the main factor influencing the maximum stress value of the primary root, and that the feather-edged margin showed the highest stress value (p = 0.002). In conclusion, shoulder and chamfer types of finish lines with a 0.4–0.6 mm thickness are recommended for deciduous tooth preparation, according to the biomechanical analysis.

Displaced Root of 3rd Maxillary Molar Tooth into Infratemporal Fossa- Role of 3D CT Scan

The displaced molar tooth is an unexpected and uncommon intraoperative complication of tooth extraction. Its prompt and early identification and management is crucial, as this may reduce the patient morbidity. Orthopantomogram (OPG) has limitations because of extensive anatomical superimposition of various structures. A 36-year-old female patient was referred for Computed Tomography (CT) of maxillofacial region with 3D CT scan for severe pain and swelling in right cheek region with inability to open mouth for 4 days following the dental intervention in outside dental clinic. CT scan of maxillofacial region showed bony defect in the right 3rd maxillary alveolus with multiple small bony fragments. Small fragment of molar tooth was displaced into the right infratemporal fossa and was impinging on right lateral pterygoid muscle with surrounding ill-defined soft tissue infiltrates in right retroantral fat. CT Face with 3D reconstruction helps in accurate localisation and gives appropriate anatomical detail in case of displaced molar tooth into infratemporal fossa. Thus, a detailed radiological investigation and documenting the relations of the displaced tooth or fragment with adjacent structures provides crucial information for proper surgical planning and avoiding possible complications.