Influence of the technical parameters of CBCT image acquisition on vertical root fracture diagnosis: a systematic review and meta-analysis.

OBJECTIVES: To evaluate the influence of image acquisition parameters (voxel, FOV, kVp, mA) on the accuracy of cone-beam computed tomography (CBCT) in detecting vertical root fracture (VRF). MATERIAL AND METHODS: Searches were performed in 6 main databases and the gray literature, without restrictions of language or date. Observational clinical studies (OCS) and in vitro-extracted teeth (IV) studies were considered eligible for inclusion when investigating the accuracy (sensitivity, specificity) of CBCT in detecting VRF in human teeth. The risk of bias was assessed using QUADAS-2, and a meta-analysis was performed using Review Manager v5.4 software and Jamovi software v1.6. RESULTS: A total of 60 out of 132 articles was included after fulfilling the eligibility criteria. Of these, 54 were IV studies while 6 were OCS. In the IV studies, it was seen that smaller FOV sizes tended to present higher accuracy values. The meta-analysis of the 6 OCS showed that the overall sensitivity and specificity values for 0.08 mm and 0.1 mm voxels were greater (0.84 and 0.79, respectively) than the sensitivity and specificity values for 0.125 mm and 0.2 mm voxels (0.70 and 0.55, respectively). CONCLUSIONS: Despite the uncertain risk of bias found for the IV and OCS studies, smaller voxel and FOV sizes seem to provide more accurate VRF detection values when using CBCT. CLINICAL RELEVANCE: This information is crucial for supporting the clinician when prescribing CBCT in cases of a clinical suspicion of VRF, and contributes to the personalization of the CBCT prescription, thereby ensuring greater accuracy in the VRF diagnosis. Registration This protocol was registered at the PROSPERO database (International Prospective Register of Systematic Review) under registration number CRD42020210118.

Accuracy of artificial intelligence for tooth extraction decision-making in orthodontics: a systematic review and meta-analysis.

OBJECTIVE: This study aimed to analyze the accuracy of artificial intelligence (AI) for orthodontic tooth extraction decision-making. MATERIALS AND METHODS: PubMed/MEDLINE, EMBASE, LILACS, Web of Science, Scopus, LIVIVO, Computers & Applied Science, ACM Digital Library, Compendex, and gray literature (OpenGrey, ProQuest, and Google Scholar) were electronically searched. Three independent reviewers selected the studies and extracted and analyzed the data. Risk of bias, methodological quality, and certainty of evidence were assessed by QUADAS-2, checklist for AI research, and GRADE, respectively. RESULTS: The search identified 1810 studies. After 2 phases of selection, six studies were included, showing an unclear risk of bias of patient selection. Two studies showed a high risk of bias in the index test, while two others presented an unclear risk of bias in the diagnostic test. Data were pooled in a random model and yielded an accuracy value of 0.87 (95% CI = 0.75-0.96) for all studies, 0.89 (95% CI = 0.70-1.00) for multilayer perceptron, and 0.88 (95% CI = 0.73-0.98) for back propagation models. Sensitivity, specificity, and area under the curve of the multilayer perceptron model yielded 0.84 (95% CI = 0.58-1.00), 0.89 (95% CI = 0.74-0.98), and 0.92 (95% CI = 0.72-1.00) scores, respectively. Sagittal discrepancy, upper crowding, and protrusion showed the highest ranks weighted in the models. CONCLUSIONS: Orthodontic tooth extraction decision-making using AI presented promising accuracy but should be considered with caution due to the very low certainty of evidence. CLINICAL RELEVANCE: AI models for tooth extraction decision in orthodontics cannot yet be considered a substitute for a final human decision.

Cone beam computed tomography in the detection of reactional osteogenesis of the maxillary sinus: a case report.

This report describes a case of reactional osteogenesis associated with the residual roots of the maxillary left first molar (tooth 14) in a 42-year-old woman. During intraoral examination, an extensive carious lesion was observed in the residual roots of tooth 14. On the periapical radiograph, a radiolucent area with well-defined limits and regular shape was observed in association with these roots. The 3-dimensional cone beam computed tomographic evaluation revealed that the hyperdense mass was homogenous, not corticated, of defined limits, and irregular in shape and had the density of bone tissue. The mass was clearly associated with an inflammatory periapical lesion. In this clinical case, volumetric analysis established a diagnosis of reactional osteogenesis and facilitated removal of the focus of infection associated with its development. Three-dimensional examination of possible changes in the maxillary sinus is crucial when infectious processes are present in the posterior region of the maxilla.

Application of image processing techniques to aid in the detection of vertical root fractures in digital periapical radiography.

OBJECTIVES: To present an image processing framework to improve the detection of vertical root fractures (VRFs) in digital periapical radiography. MATERIALS AND METHODS: Thirty endodontically treated human teeth (15 of them fractured with a metal post inserted into them, and 15 for the control) were enclosed in a dry mandible and radiographed individually. The proposed framework was applied to the raw data, as a preprocessing step, and was composed of four stages: geometric adjustment and negative, denoising, adaptive contrast enhancement, and gamma correction. The contrast-to-noise ratio (CNR) and sharpness of the image's VRF region were used for the objective evaluation of the method. In addition, five examiners evaluated the original and enhanced images, using a 5-point scale to assess confidence. RESULTS: The objective results showed that the proposed framework increased the CNR of the VRF region by 173% compared to the standard preprocessing method provided by the detector's manufacturer. The results found by the human observers indicated that the area under the curve (AUC) and sensitivity of the diagnosis of VRF significantly increased by 4% and 17% (p ≤ 0.05), respectively, when the examiners evaluated the image with the proposed method concomitantly with the image available in the commercial software. However, the specificity was reduced. CONCLUSIONS: The proposed image processing framework can be used as an additional tool to that provided by the manufacturer to increase the sensitivity and AUC of the diagnosis of VRF. CLINICAL RELEVANCE: The proposed method can be easily used in clinical practice to aid VRF detection, since it does not incur high computational costs and does not increase the radiation dose applied to the patient.

Dentin thickness as a risk factor for vertical root fracture in endodontically treated teeth: a case-control study.

OBJECTIVES: This study evaluated factors associated with vertical root fracture in endodontically treated teeth, using a cone-beam computed tomography (CBCT) image database. MATERIALS AND METHODS: The sample for this case-control study consisted of 81 CBCT scans of teeth with vertical root fracture (VRF) and 81 CBCT scans of non-fractured teeth, matched by age, sex, and tooth position. The analyzed variables included dentin thickness, an intraradicular post, an adjacent implant, and a missing adjacent tooth. Student's t test test was used to compare the quantitative variables. The chi-square test was used to compare the categorical variables. Logistic regression was performed to evaluate the association between the presence of VRF and the independent factors assessed. RESULTS: The mean dentin thickness of fractured teeth was 1.3 mm, whereas that of non-fractured ones was 1.5 mm (p < 0.001). There was no difference between the fractured and non-fractured groups, regarding implant frequency or missing adjacent tooth (p > 0.05). There were a significantly larger number of teeth with posts in the fractured versus non-fractured group (p = 0.007). However, dentin thickness ≤ 1.3 mm was the only factor associated with VRF in the multiple regression model (OR = 3.60, 95%CI = 1.76-7.37). CONCLUSIONS: Dentin thickness may influence the development of VRF. Dentin thickness ≤ 1.3 mm is associated with a greater likelihood of fracture than ≥ 1.4 mm. CLINICAL RELEVANCE: This study suggests there may be a minimum amount of safe dentin thickness that should be preserved after endodontic instrumentation.

Binary and WHO dysplasia grading systems for the prediction of malignant transformation of oral leukoplakia and erythroplakia: a systematic review and meta-analysis.

OBJECTIVES: The aim of this systematic review was to examine the evidence of the binary histologic grading system capacity for predicting malignant transformation and to compare it with that of the WHO systems. MATERIAL AND METHODS: A systematic review was conducted, using PubMed, EMBASE, LILACS, Web of Science, Scopus, and LIVIVO databases without any language or timeframe restrictions. Studies were included if they compared the binary and the WHO histologic grading systems in the prediction of malignant transformation of oral epithelial dysplasia (OED). RESULTS: The capacity of the WHO and binary grading systems to predict malignant transformation ranged from 16 to 80% and from 5 to 80%, respectively. The pooled malignant transformation rate of lesions classified as severe dysplasia or carcinoma in situ by the WHO grading was 40% (95% confidence interval (CI), 0.02-0.87; I2 = 92%; P = 0.00), while the corresponding value for lesions classified as high-risk by the binary grading system was 31% (95% CI, 0.00-0.84; I2 = 97%; P = 0.00). Overall, there was no significant difference in prognostication accuracy between the WHO and the binary systems (odds ratio = 2.02; 95% CI, 0.88-4.64). CONCLUSIONS: Although some studies suggest that the binary system is associated with lower inter-rater variability when grading OED, the evidence remains inconclusive on whether this system is superior to that of the WHO at predicting malignant transformation. CLINICAL RELEVANCE: The reproducibility of the binary system has the potential to be better for prognostic purposes. However, there is no high-quality evidence to confirm if this advantage may assist clinicians in decision-making.

Topical tetracycline in the treatment of a 7-year-old child with necrotizing ulcerative gingivitis: a case report.

A 7-year-old girl presented with necrotic gingival tissue manifesting as large ulcers in the labial and lingual gingival tissue along the region of the mandibular central incisors and right canine. The severe symptoms associated with the gingival lesions were an indication for the use of a topical tetracycline solution. The patient's parent was instructed to prepare the antibiotic solution by crushing a 250-mg tablet of tetracycline in 10 mL of distilled water. Initially, the patient was instructed to use the tetracycline solution 3 times daily for 7 days by swishing the solution around her mouth for 1 minute, expectorating the solution, and rinsing with water. After the first week, the lesions showed marked clinical improvement, and use of the antibiotic was prescribed for an additional 7 days. After 14 days of treatment, the patient presented with complete remission of the lesions. The results in the present case support the use of topical tetracycline as an effective treatment option for NUG.

Low-level laser therapy as adjunctive treatment for a sodium hypochlorite accident: a case report.

A 39-year-old woman sought specialized treatment complaining of a large, painful oral ulcer in the right buccal vestibule after receiving emergency endodontic treatment 3 days earlier. The patient reported that the tooth, the mandibular right first premolar, was not isolated with a rubber dam and that she felt the extrusion of a liquid in the buccal tissues. Clinically, a necrotic area with raised erythematous borders was observed in the mandibular right side. The clinical diagnosis was a chemically induced ulcer caused by a sodium hypochlorite accident. Dexamethasone and amoxicillin were prescribed to control pain and prevent secondary infection. The large size of the lesion was an indication for application of low-level laser therapy (LLLT), which was delivered at a wavelength of 685 nm (output power, 30 mW; power density, 0.5 mW/cm2 ; energy density, 6 J/cm2 ) every 2 days for a total of 6 sessions. The LLLT was applied to the necrotic area with a punctual mode (2 points) for 12 seconds per point. The patient reported a substantial reduction in pain after the second application, and the wound was completely healed after 6 sessions. The results observed in this patient suggest that LLLT could aid patients in recovering from NaOCl-related lesions.

Effect of Alendronate on Bone Microarchitecture in Irradiated Rats With Osteoporosis: Micro-CT and Histomorphometric Analysis.

PURPOSE: The aim of the present study was to evaluate the effect of alendronate (ALN) on the bone microarchitecture of irradiated rats with estrogen deficiency, using microcomputed tomography (micro-CT) and histomorphometric analysis. MATERIALS AND METHODS: Forty adult Wistar rats were subjected to ovariectomy and randomly divided into the following groups: control (CON), ALN, irradiated (IRR), and ALN/irradiated (ALN/IRR). Approximately 50 days after ovariectomy, the hind limbs of the rats in the IRR and ALN/IRR groups were irradiated with 15 Gy of x-radiation. The rats were euthanized 7 and 30 days after irradiation. The bone microarchitecture was analyzed using micro-CT and histomorphometry. The bone microarchitecture was evaluated using the Mann-Whitney U test, analysis of variance, and the post hoc Tukey test, with statistical significance set at 5%. RESULTS: Irradiation had increased the thickness of the cortical bone at 7 days (P < .05) and also decreased the number of trabeculae per unit length and increased the average distance between the trabeculae (P < .05) at 30 days. ALN inhibited the deleterious effect of x-radiation, preventing the distance between the trabeculae from increasing and the number of trabeculae per unit length from decreasing (P < .05). CONCLUSIONS: The present results have demonstrated that the initial effect of ALN could be positive, because it checked the deleterious action in the bone tissue submitted to x-radiation.

E-cadherin downregulation and Twist overexpression since early stages of oral carcinogenesis.

There is some evidence of Twist participation in oral carcinogenesis; however, little is known about its interaction with E-cadherin in oral squamous cell carcinoma (OSCC) development. This experimental study included an immunohistochemical analysis of Twist and E-cadherin proteins in paraffin-embedded specimens of oral leukoplakia (OL), OSCC, and normal oral mucosa. In addition, it was also performed a Western blot and double-immunofluorescence analysis of Twist and E-cadherin expression in OSCC cell lines. Significant differences in Twist and E-cadherin immunoexpression were observed between normal oral mucosa and OL, with an inverse relation since the earliest stages of oral dysplasia (r = -0,512; P < 0.001). Western blot and double-immunofluorescence analysis showed differences in Twist and E-cadherin expression among human oral keratinocytes and OSCC cell lines suggesting that downregulation of E-cadherin occurs in a dependent manner of Twist in OSCC. Our results showed a possible value of Twist and E-cadherin in the prediction of risk of oral epithelium malignant transformation.

Traumatic Ulcerative Granuloma with Stromal Eosinophilia on the Tongue.

BACKGROUND: Traumatic Ulcerative Granuloma with Stromal Eosinophilia, commonly known as Eosinophilic Ulcer, is a reactive solitary and self-limiting benign lesion. It manifests as a punched-out ulcer with a distinct surrounding indurated border, often raising concerns about malignancy. METHODS: A 44-year-old male presented with a painless, indurated tongue ulcer evolving over three months. Despite being asymptomatic, the patient underwent an incisional biopsy due to suspicions of oral squamous cell carcinoma. RESULTS: Histological analysis revealed a disrupted epithelial lining, dense necrotic connective tissue, and a fibrino-purulent pseudomembrane. Proximal to the ulcer, a collar-like projection of reactive epithelial tissue hyperplasia was noted, accompanied by mononuclear cells and a predominantly histiocytic infiltrate in the submucosal layer surrounding skeletal muscle fibers. The final diagnosis was Traumatic Ulcerative Granuloma with Stromal Eosinophilia. Remarkably, the lesion spontaneously healed within 2 weeks post-biopsy, with no recurrence over 6 months. CONCLUSION: This case emphasizes considering this benign condition in the differential diagnosis of oral ulcers, highlighting the importance of accurate histopathological evaluation to rule out cancer.

Diagnostic capability of artificial intelligence tools for detecting and classifying odontogenic cysts and tumors: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the diagnostic capability of artificial intelligence (AI) for detecting and classifying odontogenic cysts and tumors, with special emphasis on odontogenic keratocyst (OKC) and ameloblastoma. STUDY DESIGN: Nine electronic databases and the gray literature were examined. Human-based studies using AI algorithms to detect or classify odontogenic cysts and tumors by using panoramic radiographs or CBCT were included. Diagnostic tests were evaluated, and a meta-analysis was performed for classifying OKCs and ameloblastomas. Heterogeneity, risk of bias, and certainty of evidence were evaluated. RESULTS: Twelve studies concluded that AI is a promising tool for the detection and/or classification of lesions, producing high diagnostic test values. Three articles assessed the sensitivity of convolutional neural networks in classifying similar lesions using panoramic radiographs, specifically OKC and ameloblastoma. The accuracy was 0.893 (95% CI 0.832-0.954). AI applied to cone beam computed tomography produced superior accuracy based on only 4 studies. The results revealed heterogeneity in the models used, variations in imaging examinations, and discrepancies in the presentation of metrics. CONCLUSION: AI tools exhibited a relatively high level of accuracy in detecting and classifying OKC and ameloblastoma. Panoramic radiography appears to be an accurate method for AI-based classification of these lesions, albeit with a low level of certainty. The accuracy of CBCT model data appears to be high and promising, although with limited available data.

Optimizing cone-beam computed tomography exposure for an effective radiation dose and image quality balance.

Purpose: The aim of this study was to evaluate the influence of different cone-beam computed tomography (CBCT) acquisition protocols on reducing the effective radiation dose while maintaining image quality. Materials and Methods: The effective dose emitted by a CBCT device was calculated using thermoluminescent dosimeters placed in a Rando Alderson phantom. Image quality was assessed by 3 experienced evaluators. The relationship between image quality and confidence was evaluated using the Fisher exact test, and the agreement among raters was assessed using the kappa test. Multiple linear regression analysis was performed to investigate whether the technical parameters could predict the effective dose. P-values<0.05 were considered to indicate statistical significance. Results: The optimized protocol (3 mA, 99 kVp, and 450 projection images) demonstrated good image quality and a lower effective dose for radiation-sensitive organs. Image quality and confidence had consistent values for all structures (P<0.05). Multiple linear regression analysis resulted in a statistically significant model. The milliamperage (b=0.504; t=3.406; P=0.027), kilovoltage peak (b=0.589; t=3.979; P=0.016) and number of projection images (b=0.557; t=3.762; P=0.020) were predictors of the effective dose. Conclusion: Optimized CBCT acquisition protocols can significantly reduce the effective radiation dose while maintaining acceptable image quality by adjusting the milliamperage and projection images.

Prevalence of oral manifestations of leprosy: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the prevalence of oral manifestations of leprosy. STUDY DESIGN: This systematic review with meta-analysis was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and included cross-sectional studies by 2 independent reviewers in 2 phases, who reported bacilloscopic-confirmed oral manifestations of leprosy. Studies were selected based on predetermined eligibility criteria. Searches in 6 main databases were performed, such as PubMed/MEDLINE, Embase, Scopus, Web of Science, LILACS/BVS, and LIVIVO, in addition to the gray literature. The risk of bias was assessed using the JBI Checklist for Analytical Cross-Sectional Studies, and the quantitative synthesis of the data was performed using the Jamovi 2.3 application. RESULTS: Ten studies were included, and the meta-analysis was performed with 917 patients with different types of leprosy. The overall prevalence of oral alterations was 6.0% (95% IC, 0.02-0.11; I2 = 97.01%; Q = 75.56), with plaques (27.2%), infiltrations (18.1%), and macules (15.1%) being the most prevalent fundamental lesions, especially in multibacillary patients. CONCLUSIONS: Even though there is no oral pathognomonic lesion of leprosy, this infectious disease can manifest in oral tissues in different ways, depending mainly on the leprosy type and stage of treatment.

Risk of oral cancer in patients with graft-vs-host disease: A systematic review and meta-analysis.

OBJECTIVE: This systematic review was undertaken to determine the risk of oral cancer in patients with chronic graft-vs-host disease (cGvHD). STUDY DESIGN: The search was conducted in 6 electronic databases (PubMed/MEDLINE, EMBASE, LILACS, Web of Science, Scopus, and LIVIVO) and gray literature (Google Scholar, Open Gray, and ProQuest) for studies published up to November 2021. RESULTS: Of the 13 cohorts included in qualitative synthesis, 9 were eligible for the quantitative analysis. The meta-analysis showed that the presence of cGvHD increased the risk of developing oral cancer (risk ratio [RR] = 2.78; 95% CI, 1.27-6.08; I2 = 46%; P = .01). A subgroup meta-analysis revealed a higher risk of oral cancer in Asian samples exposed to cGvHD (RR = 2.50; 95% CI, 1.54-4.04; I2 = 0%; P = .0002), which was not seen in the pooled analysis of European samples (P = .24). The overall methodological quality of most studies included was "good." The cumulative evidence (Grading of Recommendations Assessment, Development and Evaluation) was considered moderate and of very low confidence for Asian and European studies, respectively. CONCLUSIONS: Patients with cGvHD resulting from allogenic hematopoietic stem cell transplantation run an increased risk of developing oral cancer. Hence, it is recommended that patients with cGvHD be monitored to allow for the early detection and treatment of secondary malignant disease.

Influence of CBCT metal artifact reduction on vertical radicular fracture detection.

PURPOSE: This study evaluated the influence of a metal artifact reduction (MAR) tool in a cone-beam computed tomography (CBCT) device on the diagnosis of vertical root fractures (VRFs) in teeth with different root filling materials. MATERIALS AND METHODS: Forty-five extracted human premolars were classified into three subgroups; 1) no filling; 2) gutta-percha; and 3) metallic post. CBCT images were acquired using an Orthopantomograph 300 unit with and without a MAR tool. Subsequently, the same teeth were fractured, and new CBCT scans were obtained with and without MAR. Two oral radiologists evaluated the images regarding the presence or absence of VRF. Receiver operating characteristic (ROC) curves and diagnostic tests were performed. RESULTS: The overall area under the curve values were 0.695 for CBCT with MAR and 0.789 for CBCT without MAR. The MAR tool negatively influenced the overall diagnosis of VRFs in all tested subgroups, with lower accuracy (0.45-0.72), sensitivity (0.6-0.67), and specificity (0.23-0.8) than were found for the images without MAR. In the latter group, the accuracy, sensitivity, and specificity values were 0.68-0.77, 0.67-083, and 0.53-087, respectively. However, no significant difference was found between images with and without MAR for the no filling and gutta-percha subgroups (P>0.05). In the metallic post subgroup, CBCT showed a significant difference according to MAR use (P<0.05). CONCLUSION: The OP 300 MAR tool negatively influenced the detection of VRFs in teeth with no root canal filling, gutta-percha, or metallic posts. Teeth with metallic posts suffered the most from the negative impact of MAR.

A three-dimensional finite element analysis of permanent maxillary central incisors in different stages of root development and trauma settings.

BACKGROUND AND OBJECTIVES: Differences in dental maturation may affect the prognosis and clinical management of traumatized teeth. However, evaluation of the outcomes of dental trauma to the tooth and support structures in an in vivo model involves major methodological and ethical implications. Thus, the aim of the present study was to perform a three-dimensional finite element analysis of permanent maxillary central incisors in different stages of root development under different trauma settings. METHODS: The study factors included two trauma conditions (B, buccal; I, incisal) on upper permanent central incisors showing three different stages of root development (CR, complete rhizogenesis; IRA; incomplete rhizogenesis in the apical third of the root; and IRM, incomplete rhizogenesis in the middle third of the root) to yield six models. The complete rhizogenesis model was obtained with a cone-beam computed tomography examination of an extracted tooth. The two incomplete rhizogenesis models were modeled on the basis of similar examinations of patients. Trauma was simulated by applying a 300 N static surface to surface load on the incisal edge or perpendicular to the buccal surface of the tooth. The displacement and equivalent von Mises (σvM) stress values were obtained for alveolar bone, periodontal ligament, apical papilla, and dentin for the quantitative analysis. A σvM color-coded scale was used for qualitative analysis. RESULTS: The force direction had a greater influence on the stress than the root-formation stage. Buccal forces resulted in higher stress concentration in the bone and periodontal ligament, especially in B-CR. Lower stress was found on the periodontal ligament as the root formation progressed (decrease of 8% from B-IRA to B-CR and 11% from B-IRM to B-CR). The incomplete rhizogenesis models showed higher σvM stress peak values in dentin in comparison with complete rhizogenesis (increase of 52% from B-CR to B-IRA and 56% from B-CR to B-IRM). CONCLUSIONS: Buccal forces yielded greater stress values regardless of the stage of rhizogenesis. Teeth with fully formed roots showed a higher stress concentration in the alveolar bone and periodontal ligament in comparison with immature teeth, with the latter presenting high stresses in the tooth crown.

Cone Beam Computed Tomography Assessment of the Volume of Dental Tissue Removed During Endodontic Access.

Introduction: The purpose of this study was to determine the volume of dental tissue removed during endodontic access preparation with cone-beam computed tomography (CBCT) comparing two different software. Methods and Materials: CBCT images of 20 teeth were obtained before and after endodontic access performed with spherical and conical diamond burs. The images were taken with i-CAT Precise system with 0.25 mm voxel size. Digital Imaging and Communications in Medicine (DICOM) images were loaded on two different software programs (Materialise® and InVersalius®), and a 3D reconstruction of the CBCT images was performed on both programs. The baseline volume (BV), and the final volume (FV) were obtained, and the lost tissue volume (LV) was calculated using the formula: LV=BV-FV. The t-test was used to compare initial and final volumes and also to compare the two programs, using a significance level of 5%. Results: The volumetric data calculated for the Materialise  and the InVesalius  programs were, respectively: BV-mean of 441.79±85.08 mm3 and 442.01±84.83 mm3; FV-mean of 426.75±83.88 mm3 and 426.94±83.75 mm3; LV-mean of 15.04±4.32 mm3 and 15.07±4.16 mm3. No statistically significant difference was found in the volumes calculated by either program for initial, final, or removed tissue (P>0.05). However, there was a significant difference between the BV and LV calculated on the same program (P<0.05). Conclusion: Our in vitro study showed that CBCT was able to determine the volume of dental tissue removed in the endodontic access preparation of extracted human teeth, regardless of the software program used.

Mesenchymal Stem Cell Marker Expression in Periapical Abscess.

INTRODUCTION: There is evidence that acute periapical lesions present a greater potential for cyst formation. Recently, it was found that these lesions have cells with characteristics of pluripotent stem cells, which may influence cyst development. However, a more complete phenotype investigation of stem cells in a specific sample of periapical abscesses is required. The aim of this study was to analyze the immunohistochemical expression of mesenchymal stem cell (MSC) markers in periapical abscesses and to evaluate differences in their expression in relation to acute and chronic periapical lesions. METHODS: Immunohistochemistry was used to access MSC marker expression (CD44, CD73, and CD105) in samples of periapical abscesses (n = 10), granulomas (n = 10), cysts (n = 10), and apical papillae (n = 10). Immunohistochemical expression was evaluated by a quantitative scoring system. The chi-square test was used to assess the association between MSC marker expression and the histopathological diagnosis at a 5% significance level. RESULTS: CD44 and CD73 immunostaining was observed in mesenchymal cells located in the outer portion of the abscess and periapical cyst specimens. CD105 immunoexpression was found predominantly in mesenchymal and vascular endothelial cells of the lesions studied. MSC marker expression was higher in the periapical abscesses, with a significant association between MSCs and the histopathological diagnosis of an abscess (P < .05). CONCLUSIONS: The periapical region is a rich source of MSCs. The greater presence of MSCs in periapical abscesses found in this study could hold an important clue into understanding the pathological pathway of periapical cyst formation.