Potential impact of metal crowns at varying distances from a carious lesion on its detection on cone-beam computed tomography scans with several protocols.

Purpose: This study evaluated the impact of artifacts generated by metal crowns on the detection of proximal caries lesions in teeth at various distances using cone-beam computed tomography (CBCT). Additionally, the diagnostic impacts of tube current and metal artifact reduction (MAR) were investigated. Materials and Methods: Thirty teeth were arranged within 10 phantoms, each containing 1 first premolar, 1 second premolar, and 1 second molar. A sound first molar (for the control group) or a tooth with a metal crown was placed. Of the 60 proximal surfaces evaluated, 15 were sound and 45 exhibited enamel caries. CBCT scans were acquired using an OP300 Maxio unit (Instrumentarium, Tuusula, Finland), while varying the tube current (4, 8, or 12.5 mA) and enabling or disabling MAR. Five observers assessed mesial and distal surfaces using a 5-point scale. Multi-way analysis of variance was employed for data comparison, with P<0.05 indicating statistical significance. Results: The area under the curve (AUC) varied from 0.40 to 0.60 (sensitivity: 0.28-0.45, specificity: 0.44-0.80). The diagnostic accuracy was not significantly affected by the presence of a metal crown, milliamperage, or MAR (P>0.05). However, the overall AUC and specificity were significantly lower for surfaces near a crown (P<0.05). Conclusion: CBCT-based caries detection was not influenced by the presence of a metal crown, variations in milliamperage, or MAR activation. However, the diagnostic accuracy was low and was further diminished for surfaces near a crown. Consequently, CBCT is not recommended for the detection of incipient caries lesions.

IS THERE AN ASSOCIATION BETWEEN AFFECTIVE TEMPERAMENT AND MORBID OBESITY IN CANDIDATES FOR BARIATRIC SURGERY? / EXISTE ASSOCIAÇÃO ENTRE TEMPERAMENTO AFETIVO E OBESIDADE MÓRBIDA EM CANDIDATOS À CIRURGIA BARIÁTRICA?

Introduction: Numerous studies have demonstrated a strong relationship between obesity and psychiatric diseases, especially mood disorders. However, few have evaluated the correlation between morbid obesity and affective temperament. Objective: To study the existence of affective temperament in morbidly obese individuals before surgical treatment of obesity. Methods: The material for reading and analysis was selected from research on virtual platforms focusing on affective temperaments (hyperthymia, dysthymia and cyclothymia). A search was carried out for descriptors related to the topic ("temperament, morbid obesity, bariatric surgery, mood disorders" and their equivalents in English with AND or OR search), considering the title and/or abstract, and then reading the work in full. Results: The most common psychiatric comorbidities in overweight and obesity were mood, anxiety and binge eating disorders. The estimated prevalence of affective temperaments in morbidly obese people is about 65%. Conclusion: The prevalence of affective temperaments is higher in morbidly obese people, candidates for bariatric surgery, compared to the general population. Cyclothymic temperament is the most common in the morbidly obese patient population.

Introdução: Inúmeros estudos têm demonstrado forte relação entre obesidade e doenças psiquiátricas, especialmente doenças do humor. Contudo, poucos avaliaram a correlação entre obesidade mórbida e temperamento afetivo. Objetivo: Estudar a existência de temperamento afetivo em obesos mórbidos antes do tratamento cirúrgico da obesidade. Métodos: O material para leitura e análise foi selecionado a partir de pesquisa em plataformas virtuais com foco nos temperamentos afetivos (hipertimia, distimia e ciclotimia). Inicialmente foi realizada busca por descritores relacionados ao tema (temperamento, obesidade mórbida, cirurgia bariátrica, transtornos do humor" e seus equivalentes em inglês com busca AND ou OR), considerando o título e/ou resumo, e a seguir a leitura do trabalho na íntegra. Resultados: As comorbidades psiquiátricas mais frequentes no sobrepeso e obesidade foram os transtornos do humor, de ansiedade e da compulsão alimentar. A prevalência estimada de temperamentos afetivos em obesos mórbidos é cerca de 65%. Conclusão: A prevalência de temperamentos afetivos é maior em obesos mórbidos, candidatos a cirurgia bariátrica, em comparação a população geral. O temperamento ciclotímico é o mais comum na população de pacientes com obesidade mórbida.

Evaluation of bone repair with platelet-rich fibrin following the extraction of impacted third molars - randomized clinical trial

Background: The aim of the present study was to evaluate postoperative effects of platelet-rich fibrin (PRF) in wound and bone healing, pain, swelling and periodontal complications outcomes after impacted third molars extraction. Material and methods: A prospective, randomized, split-mouth, double-blind clinical trial was conducted. PRF was placed within sockets following tooth removal and before suturing mucoperiosteal flap while no treatment was performed on control group's sockets. Patients were evaluated considering bone volume which was obtained in the 90-day postoperative period. Other variables included trabecular thickness, trabecular distance and grey values, pain, swelling, and wound healing. A Wilcoxon test and a t-Student test were used at a 5% significance level and a Friedman test was used to multiple comparisons. Results: Forty-four surgeries were performed in the present study. The patients' mean age was 22.41 (± 2.75 years) and 72.73% were women. PRF was associated to increased trabecular thickness and bone volume means (p < 0.001). The experimental group had significantly lower pain scores at 4h, 6h, 8h, 16h, 24h, and 72h (p ˂ 0.05). Mean swelling was lower on the experimental group (p < 0.001). The PRF group showed significant higher wound healing (p ˂ 0.001). Conclusions: Alveolar filling with PRF improves wound and bone healing after extractions while also decreasing pain and swelling in the postoperative period. (AU)

Automatic exposure compensation of digital radiographic technologies does not affect alveolar bone-level measurement.

OBJECTIVE: To evaluate whether the automatic exposure compensation in the presence of high-density materials can affect the measurement of alveolar bone level. METHODS: Thirty regions of seven dry skulls and six mandibles were radiographed with and without a high-density material, using two digital radiographic technologies: photostimulable phosphor plate (PSP, Digora Optime) and sensor (CMOS, Digora Toto), totaling 120 images. The distances from the cement-enamel junction to the alveolar bone crest were measured using cone-beam computed tomography (CBCT) images to represent the reference standard. The same measurements of alveolar bone level and the average of the pixel values of the image were evaluated on the radiographs. Paired t test compared the average pixel values and alveolar bone-level measurements between images with and without high-density material. One-way analysis of variance compared the difference between radiographic and CBCT measurements (α = 0.05). RESULTS: The high-density material reduced the pixel values in PSP (p = 0.002) and CMOS (p < 0.001) technologies, demonstrating the AEC functioning in both technologies. There was no difference in bone-level measurements between the images without and with the high-density material for both technologies (p ≥ 0.091), or between the tomographic and radiographic measurements (p ≥ 0.319). CONCLUSION: In the presence of high-density material, the automatic exposure compensation reduces the average pixel values of the images (i.e., images get darker), but does not influence the radiographic measurements of alveolar bone level.

Value-based health care in heart failure: Quality of life and cost analysis

Abstract Objectives: To measure Quality of Life (QoL) and costs of Heart Failure (HF) outpatients in Brazil as an introduction to the Value-Based Health Care (VBHC) concept. Materials and methods: Cross-sectional study, patients with HF, with ejection fraction <50%, were recruited from three hospitals in Brazil. Two QoL (36-Item Short Form Survey [SF-36] and Minnesota Living with Heart Failure Questionnaire [MLHFQ]) and two anxiety/depression questionnaires were applied. SF-36 scores were stratified by domains. Treatment costs were calculated using the Time-Driven Activity-Based Costing (TDABC) method. Results were stratified by NYHA functional class and sex. Results: From October 2018 to January 2021, 198 patients were recruited, and the median MLHFQ (49.5 [IQR 21.0, 69.0]) and SF-36 scores demonstrated poor QoL, worse at higher NYHA classes. A third of patients had moderate/severe depression and anxiety symptoms, and women had higher anxiety scores. Mean costs of outpatient follow-up were US$ 215 ± 238 for NYHA I patients, US$ 296 ± 399 for NYHA II and US$ 667 ± 1012 for NYHA III/IV. Lab/exam costs represented 30% of the costs in NYHA I, and 74% in NYHA III/IV (US $ 63.26 vs. US$ 491.05). Conclusion: Patients with HF in Brazil have poor QoL and high treatment costs; both worsen as the NYHA classification increases. It seems that HF has a greater impact on the mental health of women. Costs increase mostly related to lab/exams. Accurate and crossed information about QoL and costs is essential to drive care and reimbursement strategies based on value.

Root Curvature in Non-Syndromic Oral Clefts: A Case-Control Study in a Brazilian Population.

OBJECTIVE: This study assesses the degree of root curvature in patients with non-syndromic cleft lip and/or palate (NSCL/P). DESIGN: Retrospective. Case-control study. SETTING: Root curvature was assessed in lower premolars and molars in 800 panoramic radiographs: 400 from patients with cleft and 400 from healthy control individuals. Root curvature was classified according to its angulation, as well as its apical, medial, or coronal localization. RESULTS: The frequency of mild curvature in the NSCL/P group compared to the control group was higher in premolars especially in the left second premolar in cleft palate (OR: 6.91; 95% CI: 3.23-14.77; P < .0001). The frequency of moderate curvature in molars was significantly higher in the cleft group, with the highest risk in the right first molar in the cleft lip group (OR: 2.74; 95% CI: 1.67-4.52; P < .0001). Inclination was more frequently observed in the apical third of the root in the group with cleft, whereas for the control group, the curvature was more frequent in the medial third. In patients with cleft, the OR of curvature in the apical third was significant in premolars (left lower second premolar: Cleft lip, OR: 1.91; 95% CI: 1.04-3.52; P = .03; right lower second premolar: Cleft lip, OR: 1.91, 95% CI: 1.04-3.50; P = .03, cleft lip and palate, OR: 1.75; 95% CI: 1.12-2.73; P = .01). CONCLUSION: The results of the current study indicate differences in root curvature in patients with non-syndromic cleft lip and/or palate, which should be considered during the dental treatment planning of patients.

Influence of the Milliamperage and Artifact Reduction Tool on the CBCT-Based Diagnosis of Buccal and Lingual Peri-implant Dehiscences: Comparison Between Two Types of Implants.

PURPOSE: To evaluate the influence of the milliamperage and artifact reduction (AR) tool on the diagnosis of buccal and lingual peri-implant dehiscences related to titanium-zirconia (Ti-Zr) and zirconia (Zr) implants using CBCT images. MATERIALS AND METHODS: Ti-Zr and Zr implants were alternately inserted in 20 sites in the posterior region of three human mandibles that presented intact cortical (control) bones or simulated buccal and/or lingual peri-implant dehiscences. CBCT images were acquired with an OP300 Maxio unit, varied milliamperage (5 and 8 mA), and the use of AR tool. Three oral radiologists assessed the presence of dehiscences using a 5-point scale. The area under the receiver operator characteristic curve (Az), sensitivity, and specificity of each group (control and dehiscence) were obtained and compared using multiway ANOVA (α = .05). RESULTS: The milliamperage and the AR tool did not influence the diagnosis of dehiscences, and there were no differences between the buccal and lingual cortices (P > .05). However, Zr implants showed a higher sensitivity (0.67 to 0.89) and lower specificity (0.26 to 0.44) than Ti-Zr implants (0.19 to 0.44 and 0.93 to 1.00, respectively; P < .05). Az values did not differ between the implant types (P > .05). CONCLUSIONS: Dehiscences were more detectable when related to Zr implants, while the absence of dehiscences was more correctly visualized adjacent to Ti-Zr implants. The use of varied milliamperages and the AR tool did not affect the diagnosis of peri-implant dehiscences, regardless of the involved cortical (buccal or lingual) bones.

Influence of kilovoltage-peak and the metal artifact reduction tool in cone-beam computed tomography on the detection of bone defects around titanium-zirconia and zirconia implants.

Purpose: The aim of this study was to assess the influence of kilovoltage-peak (kVp) and the metal artifact reduction (MAR) tool on the detection of buccal and lingual peri-implant dehiscence in the presence of titanium-zirconia (Ti-Zr) and zirconia (Zr) implants in cone-beam computed tomography (CBCT) images. Materials and Methods: Twenty implant sites were created in the posterior region of human mandibles, including control sites (without dehiscence) and experimental sites (with dehiscence). Individually, a Ti-Zr or Zr implant was placed in each implant site. CBCT scans were performed using a Picasso Trio device, with variation in the kVp setting (70 or 90 kVp) and whether the MAR tool was used. Three oral radiologists scored the detection of dehiscence using a 5-point scale. The area under the receiver operating characteristic (ROC) curve, sensitivity, and specificity were calculated and compared by multi-way analysis of variance (α=0.05). Results: The kVp, cortical plate involved (buccal or lingual cortices), and MAR did not influence any diagnostic values (P>0.05). The material of the implant did not influence the ROC curve values (P>0.05). In contrast, the sensitivity and specificity were statistically significantly influenced by the implant material (P<0.05) with Zr implants showing higher sensitivity values and lower specificity values than Ti-Zr implants. Conclusion: The detection of peri-implant dehiscence was not influenced by kVp, use of the MAR tool, or the cortical plate. Greater sensitivity and lower specificity were shown for the detection of peri-implant dehiscence in the presence of a Zr implant.

Influence of artefacts generated by titanium and zirconium implants in the study of trabecular bone architecture in cone-beam CT images.

OBJECTIVES: To evaluate the influence of artefacts generated by titanium and zirconium implants on trabecular bone architecture assessment through cone-beam CT (CBCT). The influence of kilovoltage (kVp) and metal artefact reduction (MAR) in such analysis was also assessed. METHODS: CBCT scans were obtained with Picasso Trio with or without a titanium or zirconium implants in a posterior region of a mandible using 70, 80 or 90 kVp, with or without MAR. The other acquisition settings were constant: field of view 8 × 5 cm, voxel size 0.2 mm, 5 mA, 24 s and 720 frames. Two volumes of interest (VOIs) were determined comprising trabecular bone mesial and distal to the implant area. The following morphometric parameters were measured: connectivity density (Conn. Dn.), fractal dimension (FD), bone volume fraction (BV/TV), bone surface density (BS/TV), trabecular thickness (Tb. Th.), and trabecular spacing (Tb. Sp.), and compared by multiway ANOVA (α = 0.05). RESULTS: For Conn. Dn. and FD, with MAR, the zirconium group showed values significantly lower than the other groups (p < 0.05). For BV/TV, BS/TV, Tb. Th. and Tb. Sp., the zirconium group showed the highest values, regardless of MAR condition (p < 0.05). MAR increased BS/TV and Tb. Th. values, and decreased FD values for zirconium group. In general, the kVp level did not influence trabecular morphometric parameters. CONCLUSION: The assessment of the trabecular bone architecture was mainly influenced by the expression of the artefacts generated by zirconium implants. MAR decreased the FD and increased the BS/TV and Tb.Th. values regardless of the kVp level.

The impact of digital filters on the diagnosis of simulated root resorptions in digital radiographic systems.

OBJECTIVES: To evaluate the influence of digital filters of intraoral radiographic systems on the diagnosis of simulated internal and external root resorptions and image quality. MATERIALS AND METHODS: Internal root resorption (IRR) and external root resorption (ERR) were simulated in 34 teeth. For image acquisition, two radiographic systems were used: Digora Toto and VistaScan. All filters available in these systems were applied. Three observers scored the detection of root resorptions in a 5-point scale. The noise and the contrast-to-noise ratio (CNR) were calculated. The area under ROC curve, sensitivity, specificity, and accuracy were obtained. One-way ANOVA with Tukey's post hoc tests compared the diagnostic values, noise, and CNR between the filters (α = 0.05). RESULTS: For ERR, there were no significant differences in diagnostic values between the filters tested for both systems. For IRR, Original and Noise Reduction filters presented higher sensitivity than the Sharpen2 filter for images from Digora Toto, with no differences between the other groups. For VistaScan, there were no significant differences of diagnostic values between the groups studied. Noise values differed among the filters of both systems. The CNR of the filters differed only for the bone region for Digora Toto, while for VistaScan, both tooth and bone regions differed. CONCLUSIONS: Despite promoting changes in pixel intensities and affecting the noise level of the radiographic images, the digital filters of Digora Toto and VistaScan systems do not affect the diagnosis of internal or external root resorptions. CLINICAL RELEVANCE: Digital filters are common tools in digital radiographic systems and may be used by the professional without impairment in root resorptions diagnosis.

Tomographic evaluation of the effect of simvastatin topical use on alveolar bone microarchitecture, pain and swelling after mandibular third molar extraction: a randomized controlled trial.

OBJECTIVES: To evaluate the effect of a collagen sponge containing simvastatin on socket healing in terms of bone microarchitecture through tomographic analysis, pain, and swelling after impacted third molar extraction. MATERIALS AND METHODS: In this single-blind, split-mouth, randomized clinical trial, 29 patients undergoing impacted third molar extraction were allocated into two groups: (i) test group, a collagen sponge containing simvastatin was inserted within the sockets; and (ii) control group, in which sockets retained the clot. Bone volume (BV), bone volume fraction (BV/TV), trabecular thickness (Tb.Th), trabecular spacing (Tb.Sp), and gray scale were evaluated using cone beam computed tomography (CBCT) acquired immediately postoperative and 3 months after surgery. Pain, swelling, and wound healing were evaluated using the 10-point visual analogue scale, three extra-oral reference measurements, and the Landry index. RESULTS: In total, 22 participants remained in the study; no loss-to-follow-up was related to the intervention. BV and BV/TV were significantly higher at 3 months postoperatively in the test group compared with the control group and were correlated with greater bone trabeculation. Pain, edema, and the Landry index revealed a greater inflammatory response in the test group during early repair. Simvastatin contributed to bone healing, with no adverse effects or postoperative complications. CONCLUSIONS: The absorbable collagen sponge containing simvastatin improved BV, BV/TV, and trabecular bone, indicating the potential of this drug to induce the formation of autogenous bone. CLINICAL RELEVANCE: Intraosseous statins represent a promising, low-cost, and easy-to-use alternative for alveolar ridge preservation and bone regeneration. TRIAL REGISTRATION: Brazilian Registry of Clinical Trials (REBEC), No. RBR-523N7R.

Automatic exposure compensation in intraoral digital radiography: effect on the gray values of dental tissues.

BACKGROUND: This study aimed to investigate the effect of automatic exposure compensation (AEC) of intraoral radiographic systems on the gray values of dental tissues in images acquired with or without high-density material in the exposed region using different exposure times and kilovoltages. The influence of the distance of the high-density material was also investigated. METHODS: Radiographs from the molar region of two mandibles were obtained using the RVG 6100 and the Express systems, operating at 60 and 70 kV and 0.06, 0.10, and 0.16 s. Subsequently, a titanium implant was inserted in the premolar's socket and other images were acquired. Using the ImageJ software, two regions of interest were determined on the enamel, coronary dentine, root dentine, and pulp of the first and second molars to obtain their gray values. RESULTS: In the RVG 6100, the implant did not affect the gray values (p > 0.05); the increase in kV decreased it in all tissues (p < 0.05), and the exposure time affected only the root dentine and pulp. In the Express, only enamel and coronary dentine values changed (p < 0.05), decreasing with the implant presence and/or with the increase in exposure factors. The distance of the implant did not affect the results (p > 0.05). CONCLUSIONS: AEC's performance varies between the radiographic systems. Its effect on the gray values depends not only on the presence or absence of high-density material but also on the kV and exposure time used.

Radiographic diagnosis of proximal caries is not affected by exposure protocols and presence of high-density material on systems with automatic exposure compensation.

OBJECTIVES: To investigate the performance of radiographic systems with automatic exposure compensation (AEC) on the caries diagnosis in images acquired with different exposure parameters and in the presence of high-density material. Also, the image quality was assessed. METHODS: Forty posterior teeth (80 proximal surfaces) were radiographed using a phosphor plate and a CMOS system. Images were acquired with different exposure times (0.06, 0.10 and 0.16 s) and kilovoltages (60 and 70kVp), in the absence and presence of high-density material in the X-rayed region (control and high-density groups). Five radiologists assessed the caries using a 5-point scale. Diagnostic values were compared using two-way ANOVA. RESULTS: For both radiographic systems, there were no significant differences in the area under the ROC curve (0.60-0.73), sensitivity (0.79-0.87) and specificity (0.29-0.48) between the control and high-density groups, exposure times or kilovoltages (p > 0.05). For image quality, scores assigned to the control and high-density groups were similar in each exposure protocol in both systems. CONCLUSIONS: The presence of high-density material, exposure time and kilovoltage did not affect the caries diagnosis in any of the systems tested. It is recommended to use protocols with lower doses to reduce the patient's exposure.

Mapping of a multilayer panoramic radiography device.

OBJECTIVE: To map the shape, location, and thickness of the focal trough of a panoramic radiography device with a multilayer imaging program. METHODS: An acrylic plate (148 × 148 × 3 mm) containing 1156 holes distributed in a matrix of 34 × 34 rows was placed in the OP300 Maxio at the levels of the maxilla and mandible. 20 metal spheres (3.5 mm in diameter) were placed on the holes of the plate under 15 different arrangements and panoramic images were acquired for each arrangement at 66 kV, 8 mA, and an exposure time of 16 s. The resulting panoramic radiographs from the five image layers were exported, the horizontal and vertical dimensions of the metal spheres were measured in all images using the Image J software, and the magnification and distortion rates of the spheres were calculated. All metal spheres presenting a magnification rate lower than 30% in both vertical and horizontal dimensions and a distortion rate lower than 10% were considered to map the focal troughs of each of the five image layers. RESULTS: All panoramic image layers had a curved shape ranging from 39° to 51° for both dental arches and varied in position and thickness. The anterior region of maxilla was anteriorly displaced when compared to the anterior region of the mandible for all layers. Image layers are thicker at the level of the mandible than those at the level of the maxilla; also, inner layers were thinner and outer layers were thicker. CONCLUSION: All image layers in the studied panoramic radiography device had a curved shape and varied in position and thickness. The anterior region of maxilla was anteriorly displaced when compared to that of the mandible for all layers.

Identifying misconceptions about oral radiology and medicine among dental students.

PURPOSE/OBJECTIVES: Misconceptions are learning deficiencies that can lead to inappropriate clinical decision-making in dental practice. Although misconceptions are common among students, they are rarely analyzed in dental education. Thus, this study aimed to identify and analyze students' misconceptions about oral radiology and medicine at a Brazilian dental school. METHODS: Between October 2019 and March 2020, a self-administered anonymous questionnaire was distributed to dental students at the Federal University of Pernambuco, Brazil, which comprised multiple-choice questions about oral radiology and medicine. The questions were divided into two groups: 10 knowledge-based questions (less demand for reasoning) and five scenario-based questions (higher demand for reasoning). The students' responses were assessed for correctness (correct or incorrect) and confidence (sure or unsure), while misconceptions were identified when a student was sure of an incorrect response. Pearson's chi-square test was used to analyze the variables (α = 0.05). RESULTS: A total of 1380 responses were collected. Misconceptions represented 24.3% (n = 336) of the total responses and 56.8% of the incorrect responses. The mean misconceptions per student were 3.7 (range, 0-8). Students who chose incorrect answers tended to have higher confidence levels (p < 0.001). Moreover, misconceptions were more frequent for scenario-based questions (25.7%) than for knowledge-based questions (23.7%) (p = 0.000). CONCLUSION: A large number of misconceptions existed among participants. Our findings will aid educators and students in identifying misconceptions and planning measures to prevent and correct them.

Which factors related to apical radiolucency may influence its radiographic detection? A study using CBCT as reference standard.

OBJECTIVES: This study aimed to evaluate the detection rate of apical radiolucencies in 2-dimensional images using cone-beam computed tomography (CBCT) as the reference standard, and to determine which factors related to the apical radiolucencies and the teeth could influence its detection. MATERIALS AND METHODS: The sample consisted of exams of patients who had panoramic (PAN) and/or periapical (PERI) radiography and CBCT. The exams were assessed by 2 oral radiologists and divided into PAN+CBCT (227 teeth-285 roots) and PERI+CBCT (94 teeth-115 roots). Radiographic images were evaluated for the presence of apical radiolucency, while CBCT images were assessed for presence, size, location, and involvement of the cortical bone (thinning, expansion, and destruction). Diagnostic values were obtained for PERI and PAN. RESULTS: PERI and PAN presented high accuracy (0.83 and 0.77, respectively) and specificity (0.89 and 0.91, respectively), but low sensitivity, especially for PAN (0.40 vs. 0.65 of PERI). The size of the apical radiolucency was positively correlated with its detection in PERI and PAN (p < 0.001). For PAN, apical radiolucencies were 3.93 times more frequently detected when related to single-rooted teeth (p = 0.038). The other factors did not influence apical radiolucency detection (p > 0.05). CONCLUSIONS: PERI presents slightly better accuracy than PAN for the detection of apical radiolucency. The size is the only factor related to radiolucency that influences its detection, for both radiographic exams. For PAN, apical radiolucency is most often detected in single-rooted teeth.

Combined Use of 2 Cone-beam Computed Tomography Scans in the Assessment of Vertical Root Fracture in Teeth with Intracanal Material.

INTRODUCTION: The purpose of this preliminary study was to evaluate the diagnostic accuracy of the combined use of 2 cone-beam computed tomographic (CBCT) volumes obtained with the tooth of interest positioned at different orientations in the detection of vertical root fracture (VRF). METHODS: Thirty single-rooted teeth were divided into 2 main groups (n = 15): control and with VRF. The teeth were individually placed in a phantom composed of a human skull and mandible, which was CBCT scanned in 2 spatial orientations: conventional (with the Frankfurt plane parallel to the floor) and angled acquisition (tilted 90° backward). Also, each tooth was scanned with gutta-percha, a metal post, and without any intracanal material. Three oral radiologists individually evaluated the images resulting from conventional acquisition and verified the presence or absence of VRF (conventional CBCT assessment), setting a score on a 5-point scale. Subsequently, the observers evaluated both images resulting from the conventional and angled acquisitions (combined CBCT assessment). The diagnostic values of the conventional and combined assessments were compared using 2-way analysis of variance with the post hoc Tukey test. The significance level was set at 5% (α = 0.05). RESULTS: The combined CBCT assessment showed higher accuracy and sensitivity in the VRF diagnosis of teeth filled with gutta-percha (P < .05). In teeth with a metal post, all diagnostic values were higher in the combined CBCT assessment (P < .05). CONCLUSIONS: This preliminary study suggests that the CBCT-based diagnosis of VRF in teeth with intracanal material was improved when the assessment combines images obtained at 2 orientations.

Do the number of basis images and metal artifact reduction affect the production of artifacts near and far from zirconium dental implants in CBCT?

OBJECTIVES: This study aimed to evaluate the influence of the number of basis images and the metal artifact reduction (MAR) tool on the production of artifacts near and far from a zirconium implant in cone-beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT scans of a mandible were acquired before and after insertion of an implant, using 450 and 720 basis images, with and without MAR activation. The mean and standard deviation (SD) of the gray values of the regions of interest (ROIs) located on the cortices adjacent to the implant and at different distances from it (in the soft tissue) were calculated. The mean of the gray values was used to calculate the absolute contrast difference (ACD) between the control and implant scans. RESULTS: In general, the number of basis images did not affect the SD and the ACD values of the buccal and lingual ROIs (p > 0.05). The implant increased the SD in the lingual cortical plate (p < 0.05). In this case, MAR activation decreased SD (p < 0.05). All ROIs located at different distances from the implant showed higher SD on scans acquired with 450 basis images (p < 0.05), regardless of MAR condition. CONCLUSIONS: A higher number of basis images reduces the magnitude of artifacts but does not influence the image quality in bone cortical plates. MAR improves the image in the areas most affected by artifacts. CLINICAL RELEVANCE: The number of basis images is known as a factor capable of influencing the image quality and radiation dose for the patient. Therefore, it is important to investigate its effect on the expression of artifacts in the CBCT images.

Does the administration of meloxicam before head and neck radiotherapy reduce the risk of mandibular osteoradionecrosis? An animal model study.

OBJECTIVE: To assess whether the administration of meloxicam before head and neck radiotherapy reduces the risk of mandibular osteoradionecrosis in rats. MATERIAL AND METHODS: Sixty male Wistar rats were randomly divided into 6 groups (n = 10) according to the meloxicam administration and radiation therapy: control (C), irradiated (I), single dose of meloxicam (M1), single dose of meloxicam and irradiated (M1I), triple dose of meloxicam (M3), triple dose of meloxicam and irradiated (M3I). Meloxicam was administrated (20 mg/kg per dose) 1 h before the radiation therapy (single dose of 20 Gy) and 24 h and 48 h after the radiation therapy for groups with two additional doses. Ten days after the radiation therapy, the three right mandibular molars were extracted from all rats, who were euthanatized after 21 or 35 days (n = 5 per group). The mandibles were assessed by macroscopic evaluation and micro-CT analysis. RESULTS: The right hemimandibles of the irradiated groups revealed macroscopic signs of osteoradionecrosis, and those of the non-irradiated groups revealed complete gingival healing. A significant delay in alveolar socket healing in all irradiated groups was observed in the micro-CT assessment regardless meloxicam treatment. CONCLUSION: The administration of meloxicam before head and neck radiotherapy does not reduce the risk of mandibular osteoradionecrosis when associated to dental extractions. CLINICAL RELEVANCE: Since meloxicam has been shown to be a potential radiation-protective agent, and osteoradionecrosis physiopathology is believed to be related to an inflammatory process, possible interactions are relevant to be investigated.

Guided Endodontic Access in a Calcified Central Incisor: A Conservative Alternative for Endodontic Therapy.

Guided endodontic access is a promising method to treat teeth with pulp calcification. This report aimed to describe a case of root canal treatment performed through guided endodontic access in a calcified anterior tooth with apical periodontitis. A 23-year-old female with a history of trauma 10 years ago in the anterior maxilla was referred to the dental office. Her chief complaint was discolouration of the left central incisor crown. The tooth was sensitive to percussion and responded negatively to pulp sensitivity tests. The periapical radiography showed pulp calcification and periapical radiolucency. Cone-beam computed tomography (CBCT) was obtained to allow a more detailed view of the pulp canal and the periapical area. An intraoral scan was performed and the standard tessellation language (STL) archive was combined with digital imaging and communications on medicine (DICOM) images from CBCT in the Implant Viewer software. Subsequently, a 3D model was designed and printed to guide the endodontic access in position and appropriate angulation for dental instrumentation. The mold was positioned on the patient's tooth and the root canal treatment was performed. After two years, complete healing of periapical tissues was observed. This method facilitates the drill targeting during access, reducing the risk of deviations and perforations.