Molar Teeth Research Articles

Evaluation and Comparison of Dentin Thickness, Centering Ability, Canal Transportation, and Instrumentation Time of Pro AF Baby Gold and Pedoflex Files in Primary Root Canals Using a Cone Beam Computed Tomographic Analysis: An In Vitro Study.

Pediatric rotary systems have the advantage of improved canal centricity and conservative canal preparation with better obturation quality. Pro AF Baby Gold and Pedoflex files are two exclusive pediatric rotary file systems that were introduced in recent times. The aim of the present study is to compare and evaluate the dentine thickness, centering ability, canal transportation, and instrumentation time of Pro AF Baby Gold and Pedoflex files using cone beam computed tomography (CBCT). A total of 40 extracted human primary molar teeth with a minimum 7 mm root length were included in the study and randomly divided into two groups: group I, Pro AF Baby Gold; group II, Pedoflex files. Teeth were imaged preoperatively with CBCT, then root canal preparation was done in both groups with respective files, followed by postoperative CBCT imaging to evaluate the dentin thickness, centering ability, and canal transportation of both groups. Instrumentation time was noted using a stopwatch. There is a statistically significant difference in the instrumentation time; Pedoflex took a shorter time when compared to Pro AF Baby Gold files. Regarding canal transportation, there was no significant difference between the two files, with Pedoflex showing a better value than the other files. Regarding centering ability, there was no significant difference between the two files, with Pro AF Baby Gold having a better value than the other files (p < 0.001). From the findings of our present study, it was found that both systems were able to effectively shape curved root canals in terms of canal transportation and centering ability. Busi S, PJ N, Deoghare A, et al. Evaluation and Comparison of Dentin Thickness, Centering Ability, Canal Transportation, and Instrumentation Time of Pro AF Baby Gold and Pedoflex Files in Primary Root Canals Using a Cone Beam Computed Tomographic Analysis: An In Vitro Study. Int J Clin Pediatr Dent 2024;17(8):892-897.

Dentitions of Long-Term Care Residents: Tooth Types, Roles in Occlusion and Association with Dementia.

Background/Objectives: Many older adults living in long-term care (LTC) environments have varying numbers of retained natural teeth. The objective of this study was to assess the disease findings based on tooth type and estimate the role of tooth types in occlusion. Methods: We conducted clinical oral examinations of 276 LTC residents. The disease findings were analyzed for each tooth type and to determine their associations with dementia. Results: In total, 67.8% of the participants had molar teeth. Premolars/canines were often present as residual roots and had caries. Deepened periodontal pockets and higher plaque index (PI) values for molars had odds ratios of 2.5 (95% confidence interval [CI] of 1.59-3.91) and 1.61 (95% CI of 1.29-2.02), respectively. Participants with dementia were more likely to have incisors and premolars/canines in the form of root remnants and higher PI scores for all tooth types (p ≤ 0.01), as well as more deepened periodontal pockets in all teeth (p = 0.029), than those without dementia. The median number of remaining molars per participant was 3 out of a maximum of 12 (95% CI 3.4-4.0); thus, they often lacked occlusal contact. Conclusions: The LTC residents' molars were more prone to periodontal problems, whereas their premolars/canines often had caries or were present in the form of root remnants, especially in the participants with dementia. People's teeth should be treated in an easy-to-maintain way before they move into LTC to enable daily oral hygiene measures and maintain oral health.

Biallelic TXNDC15 variants associated with Joubert syndrome-related molar tooth sign and forebrain malformation

Biallelic TXNDC15 variants associated with Joubert syndrome-related molar tooth sign and forebrain malformation

Effects of minimally invasive endodontic access cavity in molar teeth on polymerization, porosity and fracture resistance

Minimally invasive access cavities have been proposed in the last decade to reduce tooth tissue loss during endodontic treatment and mitigate compromised fracture resistance of endodontically treated teeth. Fracture resistance of molars with different types of access cavity design may be affected by restorative materials and aging. Insufficient literature data exist on the effect of cavity design and type of restorative materials on restorative aspects such as material adaptation or photo-polymerization in restricted access cavities. This study analyses quality of polymerization, material adaptation and fracture resistance of molars with different types of access cavities restored with glass-ionomer, high-viscosity fiber-reinforced bulk-fill and nanofilled resin composite. Plastic molar teeth with truss (TREC) and traditional endodontic access cavity (TEC) were restored with nanofilled composite (Filtek Supreme), glass-ionomer Fuji IX and Filtek or fiber-reinforced everX Posterior and Filtek. Porosity was determined using microcomputer tomography and the degree of conversion of resin-based materals using micro-Raman spectroscopy. Human molars prepared and restored in the same way were used for fracture resistance testing at baseline and after thermocycling. The results demonstrate that high-viscosity fiber-reinforced composite was difficult to adapt in TREC cavity leading to greater porosity than Filtek or Fuji. TREC design did not affect composite polymerization and led to higher fracture resistance of restored molars compared to TEC but also more unrestorable fractures.

Effect of Hyaluronic Acid on Socket Healing After Lower Impacted Third Molar Tooth Extraction in 40 Dental Patients.

BACKGROUND Surgical extraction of impacted mandibular third molars is the most commonly performed procedure in oral surgery; its associated complications include sensory nerve damage, swelling, and trismus. This study aimed to evaluate the effects of hyaluronic acid (HA) on healing of the socket following extraction of the lower impacted third molar tooth in 40 dental patients. MATERIAL AND METHODS This prospective, double-blind, randomized, controlled study was carried out on 40 adult healthy patients indicated for surgical removal of bilateral impacted mandibular third molars with equal surgical difficulty (moderate surgical difficulty according to the Koerner index. Patients with right mandibular third molars were included into the study (HA) group and those with left mandibular third molars were included into the control group. Surgical removal of impacted teeth was performed at different times for each patient for proper measurement of postoperative clinical variables, including pain, swelling, and mouth opening. RESULTS Postoperative pain evaluation results using the visual analog scale (VAS) showed reduced pain levels at all observation periods. Postoperative swelling peaked in intensity within 12-48 hours, resolving between the 5th and 7th days, and there was no significant difference in pre- and postoperative measurements of interincisal opening between both groups (P>0.05). CONCLUSIONS We found that intra-socket application of hyaluronic acid after surgical extraction of impacted mandibular third molars promoted normal wound healing, and there was a clinical benefit of reduced postoperative pain and swelling.

Evaluation of Proximal Contact Tightness and Contact Area of Posterior Composite Resin Restorations

The purpose of this study is to evaluate the influence of the matrix system on proximal contact tightness (PCT) of posterior composite resin restorations. Standardized class II cavities on 180 first lower molar dentiform model teeth (Frasaco GmbH, Tettnang, Germany) were prepared. Three groups were formed considering the matrix system: Group-IM: Ivory matrix (Hahnenkratt GmbH, Königsbach-Stein, Germany), Group-OM: Omni matrix (Ultradent, South Jordan, UT, USA), and Group-PM: Palodent V3 sectional matrix (Dentsply, Charlotte, NC, USA). Teeth were restored with resin composite mounted in a manikin head to simulate the clinical environment. Proximal contact tightness (PCT) was measured using a custom-made portable dental pressure meter (PDPM), and the validation of the PCT results was performed with a histogram analysis acquired from bite-wing radiography. All data were statistically analyzed by ANOVA and t-test in SPSS software (v.27.0) (p &lt; 0.05). PM group showed statistically tighter contacts on both mesial (PCTm: 228.28 ± 59.17 N) and distal surfaces (PCTd: 254.91 ± 65.69 N) (p &gt; 0.05). Mesial contacts were found to be significantly tighter than distal contacts among all (p &lt; 0.05). According to the histogram results, only in the PM group, the difference between the mesial and distal areas is significant (p &lt; 0.05). Histogram results confirmed that the tightest contact values were achieved in the PM group, followed by the OM and IM groups, respectively (p &lt; 0.05). The use of sectional matrix systems and separation rings is more effective in creating tighter contact than conventional matrix systems. The use of anatomical wedges will help to create a more natural approximal contour and narrow contact area.

A comparative analysis of postoperative morbidity and alveolar bone regeneration following surgical extraction of ımpacted lower third molar teeth using piezosurgery and conventional ınstruments: a split-mouth clinical ınvestigation

Background-objective(s)This randomized, split-mouth study aimed to compare postoperative complications following the surgical extraction of impacted lower third molars using piezosurgery versus conventional rotary instruments.Materials and methodsTwenty-one patients, aged 18–35 years, with bilaterally and symmetrically impacted lower third molars, were randomly assigned to undergo extraction using piezosurgery on one side and conventional rotary instruments on the other.ResultsThe piezosurgery method required a longer operation time. However, it resulted in quicker resolution of postoperative swelling by the 7th day compared to the conventional method, where swelling persisted longer. Mandibular angle-tragus measurements were significantly higher with the conventional method on the 1st, 3rd, and 7th postoperative days. Although mouth opening decreased significantly after piezosurgery, it returned to preoperative levels by the 7th day, outperforming the conventional method. Postoperative pain was notably higher with the conventional method during the first four days but showed no significant difference from the 5th day onward. Alveolar bone healing was significantly better with piezosurgery at the 3rd and 6th months. Temporary paresthesia occurred in one patient from the conventional group, resolving within four weeks. Neither method resulted in alveolar osteitis.Conclusion(s)Within the study's limitations, piezosurgery demonstrated a reduction in postoperative discomfort, suggesting its advantage in enhancing patient recovery following lower third molar extractions.Clinical significancePiezosurgery, when used appropriately, can reduce postoperative complications compared to conventional methods. Clinicians should be aware of its indications, benefits, and potential challenges.Trial registration This study was registered as a clinical trial to the ClinicalTrials.gov, and the registration ID is NCT06262841 (https://clinicaltrials.gov/study/NCT06262841).

Postoperative pain after total pulpotomy and root canal treatment in mature molars according to the new and traditional classifications of pulpitis: a prospective, randomized controlled trial

BackgroundThe aim of this study was to compare postoperative pain following total pulpotomy (TP) and root canal treatment (RCT) in mature molar teeth with irreversible pulpitis. To compare the traditional pulpitis classification system with the Wolters system in evaluating postoperative pain.MethodsEighty mandibular molars with irreversible pulpitis were included and classified according to the Wolters (moderate/severe pulpitis). The teeth were randomly assigned to two groups (RCT or TP). RCT was performed following standardized protocols. TP was performed to the level of the canal orifices, and hemostasis was achieved with 2.5% sodium hypochlorite. A 3 mm layer of MTA was placed as the pulpotomy material. The teeth were restored with glass ionomer cement followed by composite. Pain scores were recorded preoperatively and, at 6, 12, 24, 48, and 72 h and 7 days after the interventions. The data were statistically analyzed using the Mann-Whitney U test, the Friedman test, the Wilcoxon signed-rank test, and the Spearman’s correlation test. The significance level was set at 0.05.ResultsSixty-four patients were analyzed at the one-week follow-up and all were diagnosed as irreversible pulpitis according to the AAE; 22 teeth were classified as moderate and 42 teeth were classified as severe pulpitis according to Wolters. There was no significant difference between TP and RCT in pain scores in moderate pulpitis patients (p > 0.05). There was a significant difference between TP and RCT at 24 and 72 h of severe pulpitis; higher pain scores were observed in the RCT (p < 0.05).ConclusionsIn patients with moderate pulpitis, the TP procedure allowed symptom relief more quickly than RCT. In patients with severe pulpitis, TP provided for significantly lower pain scores compared to RCT at both 24 and 72 h.Clinical trial registrationThe study was retrospectively registered with ClinicalTrials.gov (NCT05923619). Date of Registration: 06/16/23.

Clinical assessment of monolithic zirconia crowns fabricated using an intraoral scanner.

This in vivo study assessed the accuracy of single-tooth monolithic zirconia crowns made using an intraoral scanner (IOS) and computer-aided design/computer-aided manufacturing (CAD/CAM) technology. Thirty patients requiring single posterior crowns were selected. The teeth were prepared with a deep chamfer finish line with a 1-mm extension subgingivally and a 1-mm reduction in all surfaces by one prosthodontist. The gingival margins were retracted using a gingival retraction paste before making impressions using a Trios scanner. All the digital impression files were sent to one laboratory using the dental designer software (3Shape, Copenhagen, Denmark). After completing the milling and sintering processes, the crowns were dyed and glazed. After removing the temporary crown, the qualitative assessment of proximal contacts of definitive monolithic zirconia crowns was performed according to the CDA criteria. Data were analyzed with Friedman's two-way analysis and independent t-test at α=0.05. The difference in axial and total gaps between premolar and molar teeth was not significant; however, the mean marginal gap of molars was higher than that of the premolars (P=0.043). Furthermore, the comparison of the axial, total, and marginal gaps between the upper and lower jaws showed no significant difference (P>0.05). The distribution of occlusal and proximal contacts indicated 60% and 66.7% proper contacts and no contacts in 6.7% and 10% of cases, respectively. Using IOSs could result in accurate monolithic zirconia crowns in terms of adaptation. Also, most occlusal and proximal contacts did not need any adjustments.

Performance Evaluation of Deep Learning Models for Dental Caries Classification via Panoramic Radiograph Images

Objective: The purpose of this study is to evaluate the ability of deep learning models to classify mandibular molar teeth according to the presence and proximity of caries to the dental pulp. This research summarizes the progress of artificial intelligence and potential dental problems in diagnosis, treatment, and disease prediction in medicine. It discusses data limitations, computational power, ethical considerations, and their implications for dentists. This can lay the groundwork for future research in this rapidly expanding field. Methods: The dataset used in this study consists of 1200 panoramic radiographs, which have been evaluated and classified into three categories: free of dental caries, coded as (H); enamel-dentin caries lesions treated with restorative filling, coded as (R); and deep dental caries that underwent root canal treatment, coded as (E). The images are prepared for the training-testing process using the k-fold crossevaluation technique and then fed into the pre-trained deep learning models for classification. Results: The VGG-19 model achieved superior results compared to the other models, with macro-average scores of 0.9111 for precision, 0.9127 for recall, and 0.9115 for f1-score, respectively. Conclusion: The promising results obtained in this study give confidence in endorsing the use of deep learning models in the dental treatments sector.

Efficacy of Potassium Iodide and Glutathione for Correlation of Dentin Discoloration Caused by Silver Diamine Fluoride.

This study aimed to investigate and contrast the degree of dentin discoloration resulting from the application of silver diamine fluoride (SDF) alone, SDF in combination with potassium iodide (KI), and SDF in combination with glutathione. The aim was to assess the effectiveness of these combinations in reducing the aesthetic issues associated with SDF treatment in minimally invasive dentistry and preventive procedures. We conducted this in-vitro study on 136 permanent molar teeth. The teeth were randomly assigned to two main groups of total-etch and self-etch and four subgroups of control, SDF, SDF plus KI, and SDF with glutathione. The teeth underwent colorimetry before and 1 week after applying materials to compare the color change. We mounted the teeth in acrylic resin 1 mm below their cementoenamel junction. A low-speed diamond saw and 600-grit silicon carbide abrasive paper eliminated the occlusal enamel for 10 seconds under water coolant, exposing the dentin. The teeth were then immersed in a demineralizing solution (pH of 4.4, 50 mmol acetate, 2.2 mmol potassium dihydrogen phosphate, and 2.2 mmol calcium chloride) for 7 days at 37°C to induce dentin demineralization and simulate demineralized dentin artificially. The teeth were then gently polished with 600-grit silicon carbide abrasive paper to create a standard smear layer and eliminate the demineralized dentin layer. 136 teeth were evaluated in the total-etch (n = 68) and self-etch (n = 68) groups. Glutathione and KI significantly decreased the discoloration caused by SDF (P<0.05). No significant difference was noted in color change between SDF/glutathione and SDF plus KI groups (P > 0.05). In self-etch groups, glutathione yielded an ∆E=4.12, while KI yielded an ∆E=4.44, with no significant difference. The application of glutathione and KI can significantly decrease dentin discoloration caused by SDF.

Demographic and Clinical Characters of the Patient of Condylar Fracture Treated under the Department of Oral and Maxillofacial Surgery in a Tertiary Level Hospital

Introduction: Mandible is the only mobile bone of the facial skeleton which plays an important role in mastication, speech and deglutition. Being a prominent bone of the facial skeleton, it is one of the most common facial bone to be fractured. Fracture in the mandible causes severe loss of function and disfigurement. Objective: The aim of this paper was to investigate the demographic and clinical characteristics of the patients of condyle fracture treated under the oral and maxillofacial department of a tertiary level hospital of Bangladesh. Methods: This retrospective cross-sectional descriptive type of study was conducted at the Department of Oral and Maxillofacial Surgery in Dhaka Dental College and Hospital, Dhaka, Bangladesh during June, 20 23 to December, 2023. A consecutive sampling technique was used and a series of 120 cases of condyle fracture aged 17-65 years of both sex were retrospectively enrolled in this study. The data were analyzed using Statistical Package for Social Sciences (SPSS), version-23.0. Results: A series of 120 cases of condyle fracture patients were enrolled in this study. Among the patients, the most frequent age group was 30-39 years which includes 62(51.25%) patients. The mean age of the patients was 41.10±10.21 years. A significant gender disparity was observed, with 87(72.5%) of the patients being male. Most of the patients were service holder 63(52.5%). The major cause of injury of the patients was road traffic accident 75(62.5%).Among the study patients, 111(92.5%) had third molar teeth present. Of them, the most frequent 75(67.56%) patients had erupted third molar condition and 36(32.43%) patients had impacted third molar condition. According to distribution of type of impacted teeth, 21(50%) cases, had oriented vertically and followed by mesioangular 11(25%), disto-angular 4(10.7%), and horizontal 6(14.3%). According to distribution of condylar fracture, the most frequent 73 (6.25%) patients had non-displaced injuries. followed by displaced 36(30%) and dislocated 11(8.75%). Conclusion: This study investigated that road accident is the principal factor of condylar fracture and third molar teeth and its position has a significant impact on condylar fracture and at the same time the male are the more prone to condylar fracture than the female in Bangladesh

Cumulative effect of digital manufacturing techniques, preparation taper and finish line designs on the retention of aged temporary molar crowns − An in vitro study

ObjectiveThis study evaluated the effects of finish-line design, tooth preparation taper or total occlusal convergence (TOC), and digital production technology on the retention of provisional crowns for molars. Material and MethodsDifferent taper angles (10° TOC and 20° TOC) and finish line designs (chamfer and shoulder) were used to prepare four mandibular first molar teeth. Two subgroups of the prepared teeth received temporary crowns that were either “Computer-Aided Design” and “Computer-Aided Manufacturing (CAD/CAM) milled or 3D printed. Hence, eight test groups of temporary crowns containing 10 samples each were created. Groups 1–4 were milled, and Groups 5–8 were 3D printed specimens. A consistent procedure was used to cement 80 temporary crowns. The specimens were thermocycled for a total of 5000 heat cycles, initially at 5 °C for 30 s (dwell time) and then at 55 °C for 30 s. The pull-off force necessary to remove the temporary crowns was recorded, and the tensile strength, which served as the dependent variable, was calculated. Analysis of variance (ANOVA) was used to assess the variations in retention forces among the test groups. ResultsThe mean tensile strengths at maximum load [MPa] were higher in Groups 5, 6, 7, 8 (6.6 MPa, 6.91 MPa, 7.65 MPa, and 7.45 MPa respectively) as compared to the mean tensile strengths at maximum load [MPa] in Groups 1, 2, 3, 4 (2.35 MPa, 3.52 MPa, 3.21 MPa, and 2.45 MPa respectively). ConclusionFor extended periods, 3D-printed crowns with steeper preparation tapers (20° TOC) and shoulder finish lines exhibited enhanced retention.

Comparative Evaluation of Stress Distribution and Deformation in Class II Cavities Restored With Two Different Biomimetic Restorative Materials: A Three-Dimensional Finite Element Analysis.

Aim This study aims to comparatively evaluate the stress distribution and deformation in class II cavities restored with EverX posterior and ActivaTMBioactive restorative material using three-dimensional finite element analysis. Methods On a mandibular first molar tooth model, features of a class II mesio-occlusal cavity were designed. Following the application of EverX Posterior and ActivaTMBioactive, the model was subjected to a 600 N static occlusal load. Three-dimensional finite element analysis was used to analyze the distribution of occlusal stresses among the remaining components and restorative materials. von Mises and maximum principal stresses were evaluated and compared. Results von Mises and maximum principal stresses of ActivaTMBioactive components were higher compared to the control group and EverX Posterior model. ActivaTMBioactive restorations had absorbed more stresses within the material rather than distributing it to enamel and dentin than EverX Posterior material. Also, deformation was extremely high in the ActivaTMBioactive model, which may be because of less stiffness of the material. Conclusion EverX posterior has a higher capacity to bear stresses in stress-bearingareas than ActivaTMBioactive Restorative.

In Vitro Study Of Molar Tooth With Endodontic Treatment At Endocrown Successful Prosthetic Rehabilitation

Background: Side teeth, having a decisive role for mastication, require special attention after endodontic treatment. The rehabilitation of these teeth includes the analysis of current restoration techniques, materials used, as well as aesthetic and functional impact on the patient. Through a multidisciplinary approach, it aims not only to recover dental function, but also to improve the quality of life of the patient by restoring a healthy and harmonious smile. Materials and Methods: In this study, we conducted tests on 30 extracted teeth that had whole or partially whole dental crowns, the condition of selecting the tooth in the study being at least 3 mm of dental tissue present, and, necessary for the subsequent prosthetic preparation for endocrown prosthetics. The 30 teeth were divided into 6 batches, the control group (A) being made up only of integral teeth that were milling for covering crowns. The other teeth were divided into 5 batches (B-F) of 5 teeth, the teeth were endodontically treated and milling for prosthetic rehabilitation with endocrown. Each lot (B-F) benefited from a preparation of coronoradicular cylindrical shape of different depths between 0.5-2,5mm, on the occlusal face of the tooth in the endodontic access area, in order to increase the surface of the retention coronary dental tissues for the stability of the prosthetic crowns of the coating. Each tooth in A-F batches has benefited from 3 crowns made of the same material through 3 different technologies. Results: The values recorded by the A-lot, rehabilitated with crowns of sheathing on integral teeth, recorded an average value of the crown extraction force on tooth of 25.42±0.55 for CAD-CAM technology, for crowns made by baro-thermo-polymerization technique an average of 24,14±0,37, and for hot polymerization technique an average of 23,66±0,37. For B-F batches, the closest values for the extraction of endocorons were obtained by lot D with a preparation in the corono-radicular axe of 1,5mm, both for the CAD-CAM technology with a average of 25,74±1,91, and for the technique baro-thermo polymerization with an average of 24,92±1,83. For the technique of hot polymerization batch E, who has a preparation of 2 mm in the corono-radicular axe, recording an average of the extraction force of the endocrown of 23.56±2.05. Conclusion: The success of endodontic treatment also depends on prosthetic restoration for a long-term oral rehabilitation

Evaluation of clinical and radiographic success rate of a pulpotomy in primary molar teeth treated in pediatric department of the faculty of dentistry

Evaluation of clinical and radiographic success rate of a pulpotomy in primary molar teeth treated in pediatric department of the faculty of dentistry

Duloxetine-Induced Sleep Bruxism and Tooth Fracture in Fibromyalgia

Duloxetine is a serotonin-norepinephrine reuptake inhibitor that is approved for the treatment of fibromyalgia. Duloxetine has many side effects such as nausea, somnolence, insomnia, decreased appetite, dry mouth, and constipation. Sleep bruxism is also a very rare side effect of duloxetine. In this case report, a case of a 35-year-old male patient who developed sleep bruxism in the 4th week after duloxetine use, and fracture of the 1st upper molar tooth which had previously undergone root canal treatment after severe bruxism in the 6th week was presented. Duloxetine treatment was stopped and treatment was continued with amitriptyline. The patient had a significant reduction in both bruxism and fibromyalgia symptoms after the amitriptyline treatment. Bruxism symptoms were not observed after one year of follow-up.

Apically extruded debris evaluation with the use of ProTaper Ultimate and TruNatomy files systems with and without glider preparation in primary tooth.

Information regarding the influence of resorption and glide paths on debris extrusion in primary teeth is lacking. Therefore, we evaluated debris extrusion with and without resorption and with and without the use of a path file in primary molar teeth prepared with ProTaper Ultimate (PTU) Prime and TruNatomy (TRN) Prime rotary file systems. Forty resorbed and forty non-resorbed primary molar teeth were collected. Both groups were divided into four subgroups (n = 10). The Eppendorf tubes were weighed pre-debris. The distal canals of the teeth were prepared with PTU Prime and TRN Prime file systems, with and without the use of path files. The debris-filled tubes were weighed, and the weight of only the extruded debris was calculated by subtraction. The data were analyzed using a three-way analysis of variance (ANOVA) test. The presence of tooth resorption significantly increased debris extrusion, and the use of a path file significantly decreased debris extrusion (p < 0.001). The binary and ternary interactions of the three evaluated parameters among the groups showed no significant differences in terms of the amount of debris extruded (p > 0.05). While debris extrusion was observed in all groups, the use of a glide path file in primary teeth before the preparation process resulted in less debris extrusion.

Does preheating affect the microleakage of bulk-fill composite restorations?

Aim: Microleakage is one of the most important factors in restoration failure in today’s dentistry. The aim of this in vitro study is to evaluate the microleakage of preheated bulk-fill composites. Methodology: In the study, 160 slot cavities prepared in the mesial and distal of 80 molar teeth were used. In the gingival of the cavities, Estelite Bulk Fill Flow (Tokuyama, Tokyo, Japan) in the mesial and SDR® Posterior Bulk Fill Flowable Base (Dentsply, DeTrey, Konstanz, Germany) in the distal were used, and the remaining occlusal parts were restored using FiltekTM One Bulk Fill Restorative (3M, St Paul, MN, US). Composites were applied at four different temperatures (4oC, room temperature, 39oC and 55oC). After finishing and polishing, specimens were thermocycled and then placed in 0.5% methylene blue for 24 hours. Specimens were sectioned into two parts in a mesiodistal direction, and the microleakage levels were examined by a stereomicroscope (x40). Results: In the statistical evaluation of the microleakage levels of FiltekTM One Bulk Fill Restorative applied at four different temperatures on the occlusal surface with One-way ANOVA, it was observed that there was a significant difference between the groups (p=0.02). In the comparison of the microleakage values of Estelite Bulk Fill Flow applied in the gingival region with the one-way ANOVA test at four different temperatures, there was no statistically significant difference between the groups (p&gt;0.05), while there was a significant difference between the groups using SDR® Posterior Bulk Fill Flowable Base (p=0.002). The highest microleakage values were observed at 4oC in all groups. Conclusion: The results obtained in the study show that heating bulk fill composites before polymerization is effective in reducing microleakages, but longer in vivo studies are required. How to cite this article: Aktuğ Karademir S, Akarsu S. Does preheating affect the microleakage of bulk fill composite restorations?. Int Dent Res 2024;14(2):84-92. https://doi.org/10.5577/intdentres.481

Prevalence of Middle Mesial Canal in Mandibular Molar Teeth Using CBCT

Introduction: Identification and completely cleaning the extra root canals are crucial for the success of endodontic treatment. Prevalence of the middle mesial canal (MMC) in mandibular molars is still a topic of debate due to the complex and diverse anatomy and morphology of these teeth. This study aimed to investigate the prevalence of MMC in mandibular molars using CBCT radiography. Methods: In this descriptive cross-sectional study, 300 CBCT images obtained between 1995 and 2019 in a private oral and maxillofacial radiology center in Yazd, Iran, were evaluated. The first and second mandibular molars were examined for the presence of MMC based on the patients' age, gender, tooth location, and type. Data were analyzed using SPSS 17 and the Chi-square. Results: Out of 300 mandibular molars (122 first molars and 178 second molars), MMC was found in only 18 teeth (6%). The prevalence of MMC was significantly higher in the first molars (18 cases) than in the second molars (0 cases). Twelve MMCs were observed in females and 6 in males. 12 MMCs were located in the left side and the rest in the right side. The mean age of individuals with MMC was 37.33±15.27. There was no statistically significant association between the presence of MMC and age, gender, or tooth location (P &gt; 0.05), but the prevalence of MMC was higher in the first molars than in the second molars (P = 0.0001). Conclusion: The prevalence of MMC in mandibular first molars was low in the studied population and was not detected in mandibular second molars. Nevertheless, the possibility of MMC should be considered during the treatment of teeth.