Mesial Root Research Articles

Prevalence of Middle Mesial Canal in Mandibular Molars of a Saudi Subpopulation: A Prospective Cone-Beam Computed Tomography Study.

Root canal treatment is compromised when one or more root canals are left unmanaged, especially in the case of multirooted teeth. Cone-beam computed tomography (CBCT) has the advantage of clearly recognizing the anatomical structures without any blurring and superimposition. There are few studies that assess the middle mesial canal (MMC) prevalence in the Saudi population using CBCT imaging. Thus, the present study was conducted to assess the MMC prevalence in the first and second mandibular molars in the Saudi population using CBCT imaging. Data from 616 patients and 1014 teeth were assessed. The mesial roots of the mandibular first and second molars were examined using CBCT to assess the presence of the MMC in both axial and coronal sections. The potential correlation between the prevalence of MMC was assessed with gender and age. The data collected were subjected to statistical analysis using IBM SPSS version 20.0 software (IBM Corp., Armonk, NY). The mean age was 34.39 ± 12.12 years, showing male predominance. A total of 2.6% and 0.2% cases of MMC were found in the first and second molars, respectively.A significant difference (p-value < 0.05) was observed among both genders in relation to age groupsand the presence of MMC. MMC in the first molar was seen mainly in patients aged <20 yearsand only one case was reported with MMC in the second molar among patients aged 41-60 years. A higher incidence of MMC was found in the first than the second mandibular molar. For accessing the MMC, the patient's age, high magnification, and troughing are some influential factors. In the future, clinical studies with long-term follow-ups are required to assess the influence of biomechanical preparation of MMC on the result of nonsurgical endodontic management in mandibular first as well as second molars.

Shaping outcomes of Reciproc Blue and Rotate in roots canals with band-shaped isthmuses: micro-CT study.

This study assessed the outcome of shaping the mesial roots of mandibular first molars containing band-shaped isthmuses with an isthmus floor located at the apical third with Reciproc Blue and Rotate instruments in terms of canal transportation, canal aberrations and unprepared apical canals. Pair-matched mesial roots of mandibular first molars according to their isthmus location (distance from apical foramina) and size were constructed based on quantitative measurements (length, major and minor diameter at isthmus roof and floor) on preoperative micro-CT scanning (n = 10). The pair-matched specimens were prepared either using Reciproc Blue R25 (25.08v) or Rotate (15.04, 20.05, 25.06) instruments and then subjected to a second micro-CT scanning. Micro-CT scans were analysed to evaluate the canal transportation at the apical foramen and isthmus floor levels and the frequency of procedural errors (separated instruments, artificial canal preparation, cross shaping and unprepared apical canals). Canal transportation values were compared using Mann-Whitney U, and the distribution of procedural errors was compared with chi-square tests with a 5% significance threshold. Greater transportation values were detected in the apical foramen level compared to the isthmus floor in both groups. No significant difference was detected between Rotate and Reciproc Blue groups in terms of absolute transportation values and the incidence of procedural errors (p > .05). Preparation of mesial root canals containing a band-shaped isthmus at the apical portion with Reciproc Blue and Rotate instruments caused transportation of the original canal position at the isthmus floor and the apical foramen levels and resulted in procedural errors. This ex vivo micro-CT study using controlled pair-matched specimens showed that presence of a band-shaped isthmus complicates canal preparation procedure irrespective of the preparation systems.

Syringe irrigation in confluent canals: A sequential computational fluid dynamics assessment.

This study aims to assess the influence of root canal preparation, irrigation needle design and its placement depth in the irrigation flow of confluent canals during syringe irrigation. A mandibular molar presenting two confluent canals in its mesial root was sequentially prepared and scanned by micro-computed tomography after mechanical preparation up to ProTaper Next system sizes X2 (25/.06v), X3 (30/.07v) and X4 (40/.06v). In each of the root canal preparation models, a side-vented and an open-ended needle at 5, 3 and 2 mm from the working length were included, and irrigation flow was assessed by a validated computational fluid dynamics model. The results revealed that the irrigant flowed out of the confluent canals mainly through the canal that did not have the needle. Apical penetration and renewal of the irrigant were most efficiently achieved with the use of a 30G open-ended needle and a 30/.07v preparation.

Endodontic Microsurgery for a Mandibular First Molar With a Large Lateral Canal in Mesial Root: A Case Report

Introduction: The lateral canal that occurs in the mesial root of the mandibular first molar is relatively rare. Herein we reported a rare case about a large lateral canal located in the middle of the mesial root of mandibular molar. Case report: A 38-year-old woman presented with symptomatic apical periodontitis and J-shaped bone defect similar to vertical root fracture on the mesial root of tooth #30. Endodontic microsurgery was chosen to make a clear diagnosis and treatment. The procedure was carried out with apicoectomy, root-end and lateral canal preparation, and retrograde filling. At the 1-year follow-up, clinical examination and the radiograph showed complete healing. Discussion: The untreated mesiobuccal root canal with large lateral canal was found to be the cause of the J-shaped bone defect.

Cost-effectiveness analysis of full versus selective root canal retreatment.

Selective root-canal retreatment has been proposed as an alternative to full retreatment in multirooted, root-canal-filled teeth with evidence of apical pathology, where only the affected root(s) is retreated. Whilst this option may save costs initially, failures and retreatments may compensate for these initial savings. We assessed the cost-effectiveness of full versus selective root-canal retreatment using data from a recent clinical pilot study, employing a modelling approach. A Markov model was constructed to follow up a previously root-canal treated maxillary molar with apical pathology on a single root (mesio-buccal), receiving either selective or full root-canal retreatment. A private-payer perspective in Dutch health care was adopted. Permanent molar teeth with apical lesions on the mesial root were simulated over the lifetime of initially 50-year-old patients. Teeth could have endodontic complications and require interventions such as retreatment or tooth extraction and replacement. Costs were calculated based on the Dutch dental fee catalogues. Monte-Carlo microsimulations were performed to assess lifetime costs and effectiveness (measured as tooth retention time), and the resulting cost-effectiveness. Probabilistic joint uncertainty and sensitivity analyses were performed, and cost-effectiveness at different willingness-to-pay-thresholds was evaluated. In the base-case scenario, selective retreatment was less costly (2137; 2.5%-97.5% percentiles: 1944-2340 Euro) and more effective (19.6; 18.3-20.8 Years) than full retreatment (2495; 2305-2671 Euro; 16.5; 15.2-17.9 Years) in 100% of the simulations and regardless of the willingness-to-pay threshold. Only in a worst case scenario was selective retreatment more costly, but remained more effective. Selective retreatment, when clinically applicable, is likely to be more cost-effective than full retreatment in endodontically treated molars with persistent apical periodontitis. Our results should be interpreted with caution because the quality of the underlying data is limited.

Deciduous Molars Complexity Anatomy Reveled by Computed Microtomography.

The aim of this study was to analyze the internal morphology of deciduous molars through the use of computed microtomography in a sample from Rio de Janeiro. Thirty maxillary and 30 mandibular deciduous molars (n = 60), divided in first and second primary molars, were scanned by computed microtomography. The teeth were evaluated for root number, root canals, Vertucci classification, root curvature, presence of lateral canals, furcation dentin thickness, structure model index (SMI), volume, and canal surface area. The results showed 100% of maxillary molars had three roots and Vertucci type I canal was more prevalent in this group. In the mandibular ones, type IV was more frequent in the mesial root and class I in the distal root and the cavo-interradicular canal occurred in 2 specimens. Dentin thickness in the furcation region measured 1.53 and 1.59 mm in the maxillary and mandibular, respectively. Volume and area parameters varied according to the evaluated canals and SMI demonstrated that all canals had a cylindrical shape. More detailed information about the internal anatomy of the primary molars has been described, which may help strategies in the preparation of these root canals.

Exploring the Efficacy of 6 Preparation Systems for Achieving Minimal Root Canal Transportation: A Micro-CT Investigation

IntroductionThis study aimed to assess the canal transportation with 6 preparation systems. MethodsSixty curved mesial roots of mandibular molars were scanned, and their root canals (n = 20 per group) were prepared with XP-endo Shaper, BioRace, ProTaper Next, Twisted File Adaptive, Reciproc, or Reciproc Blue systems. After preparation, a new scan was conducted, and transportation was determined by comparing the geometric center of the canal in 13,542 cross-sectional slices. The transport direction frequencies were recorded, and linear transport were compared using a Univariate GLM model and Tukey honestly significant difference tests (α = 5 %). ResultsTransportation was affected by the preparation system and root third (P < .05), with no significant effect observed for the root canal (P > .05). The Twisted File Adaptive had the highest transport (P < .05), and the lowest transports were observed with XP-endo Shaper, ProTaper Next, and BioRace (P < .05). Reciproc Blue and Reciproc showed intermediate results (P < .05). The apical and coronal third exhibited the lowest and highest transportation, respectively (P < .05). A significant interaction was observed between the preparation system and root third (P < .05). In the coronal third, transportation was mostly toward the disto-inside direction, whereas in the middle and apical thirds, transportation was predominantly toward the mesio-outside direction. ConclusionsXP-endo Shaper had the lowest mean linear transportation followed by the ProTaper Next, BioRace, Reciproc Blue, and Reciproc systems. The Twisted File Adaptive system had the worst performance. The direction of transportation was generally toward the inner aspect of the canal at the coronal third and toward the outer aspect of the curve at the middle and apical thirds.

Evaluation of roots, root canal morphology, and bilateral symmetry of maxillary first molars in a Syrian subpopulation using cone beam computed tomography.

Successful endodontic treatments require a comprehensive knowledge of the root canal anatomy, so this study aimed to investigate the number of roots, configurations of root canals, and their bilateral symmetry of maxillary first molars in the Syrian subpopulation, and also the effect of gender on this symmetry. The study sample consisted of 250 cone beam computed tomography images (140 for females; and 110 for males), including 500 maxillary first molars. Images were investigated by two endodontists. Root number and canal configuration in each root were recorded, according to Vertucci classification, by studying the image atall levels (axial, coronal, sagittal, oplique, and three-dimensional) to assess the bilateral symmetry and its relation to gender. Statistical analysis was performed with SPSS and the χ2 test was used to compare the bilateral symmetry in males and females. The most common shape of the maxillary first molars was three roots (97.6%). All the roots are symmetrical by 100% in both genders. The root canal configuration was mainly Vertucci type I classification in the distobuccally (73.6%), and palatal root (98%). While the most common types in mesial root were type II (33.3%), this root showed all different types of Vertucci classifications except type VIII, and the proportion of symmetry was (37.2%) without significant difference between the gender (p = .441). Most maxillary first molars in a Syrian population were three-rooted with fourroot canals (type II), the numbers of roots achieved perfect symmetry 100%, and higher than symmetry ratios in the number of canals and canals configurations (37.2%).

Comparison of Dentinal Defects Formation in Straight, Moderate and Severely Curved Canals by Three Distinctive Nickel Titanium Instruments: An in vitro Study.

It is stated that engine-driven instruments might cause dentinal defects during root canal preparation. These defects might spread and progress into greater fractures or vertical root fracture. This study aimed to compare the incidence of dentinal defects that might arise all through preparation of root canals, using One Shape, RaCe, and WaveOne systems in canals with a curvature (0-20°) and (20-40°). In this in vitro study, 150 mandibular first molars were enrolled. Based on the degree of curvature in the mesial roots, the samples were divided into two groups (n=75) of straight and moderately curved canals (0-20º), and severely curved canals (20-40°). Then each group was randomly divided into four sub-groups. In subgroups 1 to 3 from each group, canals were prepared using WaveOne, One Shape, and RaCe. Then all roots were sectioned at 3, 6 and 9-mm distances from the apex. The slices were evaluated using stereomicroscope at 12× magnification. The data were analyzed using the Chi-square and Fisher's exact tests and the level of significance was set at 0.05. Fracture and other defects were not found in the control groups. In canals with curvature (0-20°), WaveOne caused the maximum dentinal defects and RaCe produced the least. Moreover, in canals with curvature (20-40°), One Shape caused the maximum dentinal defects while WaveOne and RaCe caused equal dentinal defects approximately. There was a statistically significant relationship between the performance of RaCe and One Shape in canals with curvature (0-20º) and (20-40º), (pValue< 0.05) while no statistically significant difference was observed in connection to the performance of WaveOne (p> 0.05).

Evaluation of alveolar ridge preservation in sockets with buccal dehiscence defects using two types of xenogeneic biomaterials: An in vivo experimental study.

Alveolar ridge preservation (ARP) has been extensively investigated in various preclinical and clinical studies, yielding favorable results. We aim to evaluate the effects of ARP using collagenated bovine bone mineral (CBBM) alone or particulated bovine bone mineral with a non-cross-linked collagen membrane (PBBM/NCLM) in tooth extraction sockets with buccal dehiscence in an experimental dog model. The mesial roots of three mandibular premolars (P2, P3, and P4) were extracted from six mongrel dogs 4 weeks after inducing dehiscence defects. ARP was randomly performed using two different protocols: 1) CBBM alone and 2) PBBM/NCLM. Three-dimensional (3D) volumetric, micro-computed tomography, and histological analyses were employed to determine changes over a span of 20 weeks. In 3D volumetric and radiographic analyses, CBBM alone demonstrated similar effectiveness to PBBM/NCLM in ARP (p > .05). However, in the PBBM/NCLM group (3.05 ± 0.60 mm), the horizontal ridge width was well maintained 3 mm below the alveolar crest compared with the CBBM group (2.11 ± 1.01 mm, p = .002). Although the radiographic changes in the quality and quantity of bone were not significant between the two groups, the use of PBBM/NCLM resulted in greater horizontal dimensions and more favorable maintenance of the ridge profile.

Endodontic retreatment of mandibular molars with the presence of missed middle mesial root canals: An important clinical lesion

Aim: Untreated root canals may have a direct impact on root canal treatment (RCT) outcome. The aim of this case report is to describe the nonsurgical root canal retreatment of two mandibular first molars in a patient's mesial roots that had previously missed middle mesial root canals (MMC). Methodology: A 14-year-old female was referred to the our clinic with the complaint of pain in the posterior areas of the right and left mandibula. During the examination, previous RCTs [teeth 36 (mandibular left first molar) and 46 (mandibular right first molar)] were observed. Besides, these teeth have periradicular lesions in the mesial roots probably due to unsuccessful previous treatment. Nonsurgical retreatment was suggested and accepted. Access cavities were prepared and the unnoticed MMCs were detected at the isthmus connecting both mesiobuccal and mesiolingual canals. All the root canals were shaped with NiTi rotary endodontic files. During the shaping, the root canals were irrigated copiously with NaOCl, EDTA, clorhexidine, and saline solutions under a certain protocol. Calcium hydroxide was used for intracanal dressing. Gutta-percha and a resin-based root canal sealer were used for filling. Coronal restorations of the teeth were completed with a composite resin. Conclusion: At follow-up examinations after 3-, 6-, and 12-months, the teeth were asymptomatic and radiographically showed repair of the lesion. Healing was achieved without any need for further endodontic surgical intervention. How to cite this article: Başoğlu A, Harorlı H, Er K. Endodontic retreatment of mandibular molars with the presence of missed middle mesial root canals: an important clinical lesion. Int Dent Res 2023;13(2):99-103. https://doi.org/10.5577/idr.2023.vol13.no2.8 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Micro-CT Evaluation of Centering Ability and Canal Transportation of Protaper Ultimate and RevoS+ Rotary File Systems in Simulated Curved Canals

Purpose&#x0D; A successful root canal preparation is to remove infected dentin and pulp tissue and to obturate the canal three-dimensionally. This study aimed to compare the centering ability of Protaper Ultimate and RevoS+ rotary file systems in curved canals of printed mandibular first molars by using micro-computed tomography (micro-CT). &#x0D; Materials and Methods&#x0D; In this in-vitro study, 16 mandibular molar teeth were printed from resin with 45° mesial root curvature. Root canal preparation was performed according to the specified groups, either Protaper Ultimate or RevoS+. The pre-and post-preparation images were repositioned in all three spatial planes by DataViewer. All images were imported into the CTAn software for the calculation of the centering ability and transportation values. &#x0D; Results&#x0D; The results showed no significant differences between the Protaper Ultimate and RevoS+ groups in terms of the centering ratio in the most inclined part of the canal. There were also no significant differences between the groups in canal transportation. (p&gt;0.05)&#x0D; Conclusions&#x0D; Protaper Ultimate and RevoS+ rotary file systems showed similar ability in centering ratio and canal transportation in curved canals from printed mandibular molars.

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 changes in root canal length and accuracy of the electronic apex locator during different stages of endodontic treatment and retreatment.

This study evaluated changes in the root canal length (RCL) and the accuracy of the electronic apex locator (EAL) during the different stages of endodontic treatment and retreatment. Fifty-six mesial root canals of mandibular molars were selected. The actual root canal length (AL) of the canals was obtained by inserting a size 15 hand file up to the apical foramen, under magnification. The electronic lengths were obtained at the "APEX" mark of Root ZX II, using an alginate model. Both measurements were performed at three different stages of the initial root canal treatment-unflared, flared, and concluded-and at two stages of retreatment, after achieving patency and repreparation. Data were statistically analyzed and the significance level established was 5%. All stages produced a significant reduction in the AL (p < 0.05). The greatest variation was observed between the unflared-flared stages (0.2mm) and between concluded-patency stages (0.09mm), with no difference between them (p > 0.05). The accuracy of Root ZX II was negatively affected after achieving patency, presenting statistically significant difference compared to the other stages (p < 0.05). A significant reduction in the RCL was observed along the different stages of endodontic treatment and retreatment. The EAL was accurate to measure the root canals in most stages, except after achieving patency for endodontic retreatment. Determining and monitoring the RCL is an essential step towards a favorable prognosis, since it reduced along the different stages evaluated. Root ZX II was not accurate for endodontic retreatment.

Comparison of Dentin Microstructure and Its Correlation to the Direction of Fracture Line in Mandibular Molars of Young and Older Individuals: In Vitro Study

IntroductionThe aim of the study was to assess the presence and extent of sclerotic dentin and to study its impact on the direction of fracture lines in extracted mandibular first molars of young (20–44 years) and older age groups (45 and older). MethodsExtracted permanent mandibular first molars were collected along with the related demographic details. A total of 40 teeth were included in this study, 20 each from young age group (YA group) (20–44 years) and older age group (OA group) (45–70 years). All molars were decoronated, and the sectioned mesial roots were embedded in acrylic blocks. They were subjected to vertical force in a universal testing machine. Fractured roots were then examined under the stereomicroscope at ×8 magnification to determine the direction and pattern of the fracture line. The roots were then sectioned and evaluated at ×10 and ×20 magnification to assess the dentin microstructure and its correlation with the direction of the fracture line. Statistical analysis was done by using χ2 test (P < .05). ResultsA greater incidence and degree of sclerotic dentin were found in the OA group as compared with the YA group, which was statistically significant. The sclerotic dentin was distributed predominantly mesiodistally and the fracture line propagated buccolingually in both young and older groups, which was statistically significant (P < .05). ConclusionsThe presence of sclerotic dentin mesiodistally may impede crack propagation in this direction for both young and older age groups, causing the fracture line to extend buccolingually in coronal third of the root.

The efficacy of a novel SWEEPS laser-activated irrigation compared to ultrasonic activation in the removal of pulp tissue from an isthmus area in the apical third of the root canal.

This study aimed to evaluate the efficacy of Shock Wave Enhanced Emission Photoacoustic Streaming (SWEEPS) in the removal of remaining pulp tissue from the root canal isthmus area in lower molars and compare it with ultrasonically activated irrigation (UAI) and conventional needle irrigation (NI). Forty-one lower molars with isthmuses between mesial canals were included in the study. The teeth were randomly distributed into experimental groups (n = 12/each) based on the final irrigation protocol (SWEEPS, UAI, or NI) and a control group (C) (n = 5). The traditional access cavity of the mesial part of each tooth was made in all samples. The mesial root canals in the experimental groups were instrumented with a Wave One Gold Primary (25/.07) file using 3% sodium hypochlorite (NaOCl) while the distal canal served as a control for the presence of pulp tissue. No treatment was performed in the C group. Sections from the isthmus region were processed for histopathology to measure the remaining pulp tissue (RPT). The results were analyzed using analysis of variance and the Kruskal-Wallis test (α = 0.05). There were no significant differences in the relative surface area of root canals and isthmus among the groups (p > 0.05). Samples in the SWEEPS group had significantly less RPT than UAI, NI, and C (p = 0.003, 0.014, 0.003, respectively). There were no significant differences between the UAI and NI (p = 0.583). SWEEPS was the most efficient in debridement of the root canal isthmus area. UAI and NI showed similar but lower efficiency.

Comparative Evaluation of Different Irrigant Agitating Devices for Debris Removal from the Mesial Roots of Mandibular Molars: An In Vitro Study.

To evaluate the efficiency of debris removal from the mesial root canals and isthmus of mesial roots of mandibular molars after final irrigant agitation with XP-endo Shaper, EndoVac (EV), plastic finishing file, and conventional needle irrigation. Forty extracted human mandibular first molar teeth with the isthmus between the mesial roots were selected, access cavities were prepared and distal roots were decoronated. All the mesial root specimens were mounted in acrylic, sectioned at the coronal, middle, and apical thirds, along with the resin block, and examined for debris in the canals and isthmus before the start of the procedure using a stereomicroscope and were mounted back in a custom-made jig. After determination of the working length, they were allocated to the following four different irrigant activation groups (n = 10): Group I-XP-endo Finisher; group II-EndoVac; group III-plastic finishing file; and group IV-standard needle irrigation. After biomechanical preparation (BMP) till F3, final agitation was done for debris removal with the respective agitating devices, and all the samples were examined under a stereomicroscope for the amount of debris in the canal after final agitation. Of all the irrigation devices used, the XP-endo Finisher and EV showed more debris removal when compared to other groups (p < 0.05). The plastic finishing file in continuous rotation was more efficient in cleaning debris compared with conventional needle irrigation (p < 0.05). The XP-endo Finisher and EV showed a significant difference in cleaning efficacy than the plastic finishing files. So, these can be used as adjunctive for agitating the final irrigant. The irrigant agitation devices promote the penetration of irrigants into the intricate root canal anatomy and increase their antibacterial and tissue-dissolving effectiveness thereby improving the success rate and treatment outcome.

A Case Report with Two-Year Follow-Up of Auto-Transplantation Tooth

Autotransplantation of a maxillary premolar tooth is a considerable option for tooth replacement in young adult patients, while Hemisection is a conservative way of preserving teeth. In this case report, we describe successful autotransplantation of the mesial root of the mandibular molar to replace the first maxillary premolar with complete root formation. The donor root was immediately placed at the recipient site and splinted for 14 days. Root canal treatment (RCT) was initiated 3 weeks after transplantation. Clinical and radiographic findings at 24 months of follow-up are compared with the results described in the literature. In case of non-extraction, adjacent teeth can be preserved in an economical way, also, case selection is essential in performing sequences of procedures for the success of treatment.

Farklı tek eğe sistemlerinin alt çene birinci büyük azı dişlerinin tehlike alanındaki dentin kalınlığına etkisi

Background: To compare the dentin thickness in the danger zone of mandibular molars after preparation with one rotating (XP-endo Shaper) and two reciprocating (One Reci and Reciproc Blue) single file systems using a cone beam computed tomography (CBCT).&#x0D; Materials and Methods: Thirty-six mesial roots of mandibular first molars having two independent canals were selected. After initial CBCT scans were provided, teeth were assigned into 3 groups related to the single file used: XP-Endo Shaper (XPS), One Reci (OR) and Reciproc Blue (RB). The roots were scanned again after preparation with respective single file systems. The minimum dentine thickness in the danger zone, at 4, 5, 6 and 7 mm below the furcation level, were measured in CBCT scans. Initial and final measurements were used to calculate the removed dentin thickness in the danger zone. Data was analyzed using Repeated-measures ANOVA (p=0.05).&#x0D; Results : No significant differences were found related with remaining and removed dentin thickness among single file systems at any level from the furcation (p&gt;0.05). &#x0D; Conclusions: The evaluated single file systems showed similar cutting efficiency in the danger zone of mandibular molars.

Intentional replantation for the retreatment of mandibular second molar: a case report.

When the use of root canal retreatment and apical surgery experiences difficulty in treating endodontic diseases, intentional replantation is an optional clinical technique used to retain the tooth. A 28-year-old female complained of chewing discomfort at the mandibular second molar after undergoing root canal treatment 3 month ago. History record and radiographic examination revealed that a C-shaped root canal system was filled with gutta-percha in the mandibular second molar. A radiolucency area existed at the root furcal area with a thin canal wall in the distal and mesial roots. Intentional replantation was used to treat this tooth. The clinical and radiographic results showed that intentional replantation and nano-biomaterial application facilitated infection control, tooth retention, and periodontal tissue regeneration.