Optimizing radiation safety in dentistry: Clinical recommendations and regulatory considerations.

BACKGROUND: The value of dental radiographs to oral health care decision making must be balanced with radiation safety to minimize patient exposure and occupational risk of oral health care providers. This review summarizes recommendations and regulatory guidance regarding dental radiography and cone-beam computed tomography. An expert panel presents recommendations on radiation safety, appropriate imaging practices, and reducing radiation exposure. TYPES OF STUDIES REVIEWED: A systematic search run in Ovid MEDLINE, Embase, and Cochrane Database of Systematic Reviews identified relevant topical systematic reviews, organizational guidelines, and regulatory reviews published in the peer-reviewed literature since 2010. A supplemental search of the gray literature (eg, technical reports, standards, and regulations) identified topical nonindexed publications. Inclusion criteria required relevance to primary oral health care (ie, general or pediatric dentistry). RESULTS: A total of 95 articles, guidance documents, and regulations met the inclusion criteria. Resources were characterized as applicable to all modalities, operator and occupational protection, dose reduction and optimization, and quality assurance and control. PRACTICAL IMPLICATIONS: Understanding factors affecting imaging safety and applying fundamental principles of radiation protection consistent with federal, state, and local requirements are essential for limiting patient ionizing radiation exposure, in conjunction with implementing optimal imaging procedures to support prudent use of dental radiographs and cone-beam computed tomographic imaging. The regulatory guidance and best practice recommendations summarized in this article should be followed by dentists and other oral health care providers.

Patient shielding during dentomaxillofacial radiography: Recommendations from the American Academy of Oral and Maxillofacial Radiology.

BACKGROUND: The American Academy of Oral and Maxillofacial Radiology established an ad hoc committee to draft evidence-based recommendations and clinical guidance for the application of patient contact shielding during dentomaxillofacial imaging. TYPES OF STUDIES REVIEWED: The committee reviewed monographs and reports from radiation protection organizations and studies that reported radiation dose to gonads, breasts, and thyroid gland from dentomaxillofacial imaging. RESULTS: Considering the absence of radiation-induced heritable effects in humans and the negligible dose to the gonads and fetus from dentomaxillofacial imaging, the committee recommends discontinuing shielding of the gonads, pelvic structures, and fetuses during all dentomaxillofacial radiographic imaging procedures. On the basis of radiation doses from contemporaneous maxillofacial imaging, the committee considered that the risks from thyroid cancer are negligible and recommends that thyroid shielding not be used during intraoral, panoramic, cephalometric, and cone-beam computed tomographic imaging. PRACTICAL IMPLICATIONS: This position statement informs and educates the reader on evolving radiation protection practices and provides simple, unequivocal guidance to dental personnel to implement these guidelines. State and local authorities should be contacted to update regulations to reflect these recommendations.

Evaluating cone cut in rectangular collimation in intraoral radiography: application of ALADA and radiation stewardship.

OBJECTIVE: Rectangular collimation is a popular method used in intraoral radiography to reduce patient exposure to ionizing radiation. One of the perceived drawbacks of rectangular collimation is the possibility of an increase in cone cut errors ultimately impacting the diagnostic value of the radiographs. Thus, the aim of this study was to explore the frequency of cone cut errors in radiographs taken using a rectangular collimator. MATERIALS AND METHODS: Radiographs taken using PSP plates at Academic Center for Dentistry Amsterdam in the Netherlands by staff and students from January to December 2015 were assessed for cone cut errors. The radiographs were grouped as bitewings, front teeth, inferior premolars and molars, and superior premolars and molars and categorized as no cone cut, cone cut but diagnostically usable, and cone cut but diagnostically not usable. The results were entered into Microsoft Excel and analyzed thereafter. RESULTS: A total of 53,684 radiographs were assessed, 79% had no cone cut errors and consequently 21% had some degree of cone cut. However, the diagnostic value was unaffected in 18% of the radiographs with cone cut. Only 3% of the radiographs were deemed diagnostically unusable due to cone cut. The most common area of cone cut was in the premolar and molar areas while cone cut in the front teeth was least likely to be diagnostically unusable. CONCLUSION: Cone cut from the use of a rectangular collimator does not seem to result in an increase of diagnostically unusable radiographs. Thus, rectangular collimation should be preferred as it decreases the amount of radiation exposure to the patient while producing diagnostically usable radiographs and thus allowing the dental professional to adhere to the ALADA principle and practice radiation stewardship. CLINICAL RELEVANCE: Scientific rationale for the study: rectangular collimation is a method used to reduce patient exposure to ionizing radiation; however, this benefit is negligible if radiographs must be retaken due to cone cut errors that make the radiograph diagnostically unusable. Therefore, the aim of this study was to explore the frequency of cone cut in radiographs taken using a rectangular collimator. PRINCIPAL FINDINGS: cone cut was observed in 21% of the radiographs; however, only 3% of the radiographs were considered diagnostically unusable. PRACTICAL IMPLICATIONS: rectangular collimation does not result in a high number of diagnostically unusable radiographs and should be used to reduce patient exposure to ionizing radiation.

Impact of dentists and equipment in the performing dental imaging examinations: a longitudinal analysis.

In this study, we aimed to identify factors associated with performing dental imaging examinations in public health services. Brazilian data at the municipal level (n = 5,564) in two time periods, P0 (2005-2007) and P1 (2014-2016), were collated from health information systems. The increase in the municipal rates of intraoral and extraoral radiographic imaging procedures was the outcome. Changes in the use of clinical procedures and the rates of dentists and equipment were the main predictors. Multiple logistic regression analysis was performed to estimate the adjusted odds ratio (OR). Approximately 35.3% of the Brazilian municipalities increased the dental radiography equipment rate, 9.9% increased the fan-beam computed tomography (CT) equipment rate, and 5.9% increased the magnetic resonance imaging (MRI) equipment rate. In addition, 31.8% increased the periapical/interproximal radiography rate, 10.5% increased the CT rate, and 4.4% increased the MRI rate. Increases in the dental radiography, CT, and MRI rates were associated with higher chances of periapical/interproximal images (OR = 1.90, p < 0.01), face and neck images (OR =1 5.3, p < 0.01), and MR images (OR = 18.1, p < 0.01), respectively. Municipalities that increased the rates of endodontists increased the rates of periapical/interproximal (OR = 2.50, p < 0.01) and occlusal (OR = 1.60, p < 0.01) imaging procedures, and those that increased the rates of radiologists also increased the rates of occlusal (OR = 2.00, p < 0.01) and panoramic (OR = 1.70, p < 0.01) imaging procedures. The implementation of a secondary dental care center, Centro de Especialidades Odontológicas (CEO) was associated with an increase in the chances of performing periapical/interproximal and panoramic radiographic procedures in 1.5 and occlusal radiographic examinations in 2.0. The rates of dentists, equipment, specialized dental centers, and specific dental procedures were associated with the increased use of imaging procedures in dentistry in the Brazilian public health system.

[Portable X-ray devices: technique, image quality and regulations]. / Draagbare röntgentoestellen: techniek, beeldkwaliteit en regelgeving.

Portable intraoral X-ray devices are marketed as an alternative for conventional wall mounted devices. On the basis of a recent clinical trial the diagnostic quality of portables appears to measure up to the conventional devices. When CE-certified portable devices are used with rectangular collimation and a backshatter radiation shield with adapted technique resulting in a beam parallel to the ground, operator exposure stays well within dose limits. However, the dose to the operator is higher than when using conventional devices. Therefore, in the Netherlands, guidelines restrict the use of portable devices to ambulant use outside the dental clinic while deploying additional radiation protection measures. If presumed advantages of increased control over the exposure due to proximity to the patient would be substantiated by research, this restricted use could be reconsidered. Dentists should be aware of online availability of non-CE-certified portable intra-oral X-ray devices that are potentially unsafe.

A Standard Method for Intraoral Dental Radiography With Dental Photo-Stimulative Phosphor (PSP) Plates in Big Cats.

In recent years, dentistry has steadily gained more prominence in veterinary medicine, including exotic and wild animal medicine. It is known that dental diseases are among the most common diseases in captured big cats. However, so far, there is no standardized method for dental radiography in these animals. Therefore, this study aimed to develop a standardized procedure for the systematic radiographic examination of the teeth in big cats. In total, 34 big cats, including 21 lions and 13 tigers, of different ages were examined. Animals that needed treatment for known dental diseases and those that had to be anesthetized for other medically necessary procedures and dental health status examinations were included. Intraoral dental radiographs were captured with digital imaging plates designed for intraoral dental radiography in horses. Based on the intraoral dental radiography procedures used in domestic cats, both the bisecting angle technique and parallel technique were used. A hemisphere model originally developed for horses was used to describe the path and position of the x-ray beam as accurately as possible. The results demonstrated that it was possible to completely image all the teeth of big cat dentition on seven radiographs using the described method. This method can be used to acquire high-quality intraoral dental radiographs in big cats, aiding in the quick and reliable diagnosis of dental diseases.

Delaying Intraoral Radiographs during the COVID-19 Pandemic: A Conundrum.

BACKGROUND: The COVID-19 pandemic has made dentists very assiduous about cross-infection during dental treatment, thereby delaying dental radiographs for treatment. However, patients needing dental emergency treatment in the ongoing pandemic require relevant intra/extraoral dental radiography for adequate diagnosis and treatment planning. METHODS: This article is aimed at adding to the hot debate: Is delay for intraoral radiographs justified or a possible proxy? As a narrative review, it provides an insight into the reasons for delaying intra-oral dental radiographs during in the pandemic and options of the nontraditional radiographic techniques available until the pandemic subsides. Discussion and Conclusion. Cross-contamination concerns through respiratory droplets grow while using intraoral film holders that stimulate gag reflex, coughing, saliva secretion, and if proper disinfection protocols are not applied. Since the patients' acquiring emergency dental treatment cannot be neglected, the return-to-work guidelines by the health regulatory bodies urge to prioritize extraoral radiographic imaging techniques to curb the infection, offering the best diagnostic efficacy. The dental professionals can consider cone-beam computed tomography (CBCT) scans and sectional dental panoramic radiographs (SDPRs), followed by a risk assessment for COVID-19, a safer modality in reducing cross-contamination and assuring an innocuous environment for both patient and coworkers.

Diagnostic performance of periapical and panoramic radiography and cone beam computed tomography for detection of circumferential gaps simulating osseointegration failure around dental implants: A systematic review.

OBJECTIVE: The objective of this study was to appraise the diagnostic performance of periapical (PR) and panoramic (PANO) radiographs and cone beam computed tomography (CBCT) in detecting artificial circumferential gaps simulating osseointegration failure around dental implants in ex vivo studies. STUDY DESIGN: Seven electronic databases and three gray literature sources were searched. Studies reporting diagnostic performance measures or data allowing calculation of those measures compared with the reference standard of in situ direct measurements were considered eligible. Either the area under the receiver operating characteristic curve or accuracy was chosen to summarize findings, with diagnostic performance interpreted as poor, acceptable, excellent, or outstanding. Risk of bias (RoB) was also assessed. RESULTS: The ten included studies mostly suggested overall excellent to outstanding diagnostic capability with PR and CBCT. Various enhancement filters, CBCT voxel sizes, and/or fields of view were associated with acceptable to outstanding efficacy. PANO had the poorest results, with most research demonstrating acceptable to excellent discrimination. The RoB was high for seven studies, moderate for two, and low for -one. CONCLUSIONS: PR and CBCT images were generally superior to PANO for the detection of artificial bone gaps. Results should be interpreted with caution because most studies had a high RoB.

Effects of Exposure Parameters and Voxel Size for Cone-Beam Computed Tomography on the Image Matching Accuracy with an Optical Dental Scan Image: An In Vitro Study.

This study is aimed at assessing the effects of exposure parameters and voxel size for cone-beam computed tomography (CBCT) on the image matching accuracy with an optical dental scan image. CBCT and optical scan images of a dry human mandible were obtained. Different CBCT settings were used: tube voltage, 60, 80, and 100 kVp; tube current, 6 and 8 mA; and voxel size, 100, 200, and 300 µm. Image matching between the CBCT and optical scan images was performed using implant planning software by dental professionals (n = 18). The image matching accuracy in each combination of CBCT settings was evaluated by assessing the linear discrepancy between the three-dimensionally reconstructed radiological image and the registered optical scan image using an image analysis software program. The Kruskal-Wallis test and a post hoc Mann-Whitney U test with Bonferroni correction were used to compare the accuracy of image registration between the groups (α = 0.05). Overall, the image matching accuracy was not significantly different between tube voltage and current settings; however, significantly higher image registration errors were found at the combination of 100 kVp tube voltage/8 mA tube current (F = 8.44, P < 0.001). Changes in voxel sizes did not significantly interfere with the image registration results. No interaction was found among voltage, current, and voxel size in terms of image registration accuracy (F = 2.022, P = 0.091). Different exposure parameter settings in tube voltage and tube current did not significantly influence the image matching accuracy between CBCT and optical dental scan images; however, a high radiation dose could be inappropriate. The image matching accuracy was not significantly affected by changing the voxel sizes of CBCT.

Artificial Intelligence Techniques: Analysis, Application, and Outcome in Dentistry-A Systematic Review.

OBJECTIVE: The objective of this systematic review was to investigate the quality and outcome of studies into artificial intelligence techniques, analysis, and effect in dentistry. MATERIALS AND METHODS: Using the MeSH keywords: artificial intelligence (AI), dentistry, AI in dentistry, neural networks and dentistry, machine learning, AI dental imaging, and AI treatment recommendations and dentistry. Two investigators performed an electronic search in 5 databases: PubMed/MEDLINE (National Library of Medicine), Scopus (Elsevier), ScienceDirect databases (Elsevier), Web of Science (Clarivate Analytics), and the Cochrane Collaboration (Wiley). The English language articles reporting on AI in different dental specialties were screened for eligibility. Thirty-two full-text articles were selected and systematically analyzed according to a predefined inclusion criterion. These articles were analyzed as per a specific research question, and the relevant data based on article general characteristics, study and control groups, assessment methods, outcomes, and quality assessment were extracted. RESULTS: The initial search identified 175 articles related to AI in dentistry based on the title and abstracts. The full text of 38 articles was assessed for eligibility to exclude studies not fulfilling the inclusion criteria. Six articles not related to AI in dentistry were excluded. Thirty-two articles were included in the systematic review. It was revealed that AI provides accurate patient management, dental diagnosis, prediction, and decision making. Artificial intelligence appeared as a reliable modality to enhance future implications in the various fields of dentistry, i.e., diagnostic dentistry, patient management, head and neck cancer, restorative dentistry, prosthetic dental sciences, orthodontics, radiology, and periodontics. CONCLUSION: The included studies describe that AI is a reliable tool to make dental care smooth, better, time-saving, and economical for practitioners. AI benefits them in fulfilling patient demand and expectations. The dentists can use AI to ensure quality treatment, better oral health care outcome, and achieve precision. AI can help to predict failures in clinical scenarios and depict reliable solutions. However, AI is increasing the scope of state-of-the-art models in dentistry but is still under development. Further studies are required to assess the clinical performance of AI techniques in dentistry.

The Combination of Panoramic Imaging and Waters' Projection Contributes to the Diagnosis of Odontogenic Maxillary Sinusitis.

The purpose of this study was to evaluate the usefulness of adding Waters' projection to panoramic imaging compared with panoramic imaging or Waters' projection alone. Maxillary sinusitis in 106 patients (206 sinuses) was retrospectively assessed with panoramic imaging, Waters' projection, and computed tomography imaging by two oral radiologists. The diagnostic performance was assessed with computed tomography imaging as the gold standard. Receiver operating characteristic curves and area under the curve values were obtained. Inter- and intra-observer agreement was quantified using weighted kappa coefficients. Observer A performed the same procedure twice (A1 and A2 for the first and second observations, respectively). The accuracies of observers A1, B, and A2 with combination imaging were 0.699, 0.636, and 0.718, respectively. Their area under the curve values with combination imaging were 0.746, 0.640, and 0.771, respectively. Inter-observer agreement was good for Waters' projection (κ, 0.650), and poor for panoramic imaging (κ, 0281). Intra-observer agreement was good for Waters' projection (κ, 0.752), and moderate for panoramic imaging (κ, 0.597). Panoramic imaging was equivalent to Waters' projection for diagnosing maxillary sinusitis. Combination imaging comprising panoramic imaging and Waters' projection can contribute to the diagnosis of odontogenic maxillary sinusitis because of its high sensitivity.

A deep learning approach for dental implant planning in cone-beam computed tomography images.

BACKGROUND: The aim of this study was to evaluate the success of the artificial intelligence (AI) system in implant planning using three-dimensional cone-beam computed tomography (CBCT) images. METHODS: Seventy-five CBCT images were included in this study. In these images, bone height and thickness in 508 regions where implants were required were measured by a human observer with manual assessment method using InvivoDental 6.0 (Anatomage Inc. San Jose, CA, USA). Also, canals/sinuses/fossae associated with alveolar bones and missing tooth regions were detected. Following, all evaluations were repeated using the deep convolutional neural network (Diagnocat, Inc., San Francisco, USA) The jaws were separated as mandible/maxilla and each jaw was grouped as anterior/premolar/molar teeth region. The data obtained from manual assessment and AI methods were compared using Bland-Altman analysis and Wilcoxon signed rank test. RESULTS: In the bone height measurements, there were no statistically significant differences between AI and manual measurements in the premolar region of mandible and the premolar and molar regions of the maxilla (p > 0.05). In the bone thickness measurements, there were statistically significant differences between AI and manual measurements in all regions of maxilla and mandible (p < 0.001). Also, the percentage of right detection was 72.2% for canals, 66.4% for sinuses/fossae and 95.3% for missing tooth regions. CONCLUSIONS: Development of AI systems and their using in future for implant planning will both facilitate the work of physicians and will be a support mechanism in implantology practice to physicians.

Evaluación radiográfica de tratamientos endodónticos realizados por alumnos de grado. Una experiencia docente / Radiographic evaluation of endodontic treatments performed by undergraduate students: a teaching experience

Objetivo: Describir una experiencia de capacitación de alumnos de grado en la evaluación radiográfica de tratamientos endodónticos realizados ex vivo. Material y métodos: Participaron un docente y 13 alumnos, cada uno de los cuales evaluó radiográficamente 100 tratamientos endodónticos realizados ex vivo para determinar si estos eran correctos o incorrectos. Posteriormente, el mismo docente, en una clase teórica, presentó a los alumnos otras imágenes radiográficas a fin de calibrar qué debería considerarse correcto o incorrecto. Luego fueron proyectadas nuevamente las radiografías de los 100 casos, y los alumnos efectuaron una nueva valoración. Para cada alumno, se determinó la frecuencia de concordancia con el docente en los 100 casos, antes y después de la calibración. Se categorizó cada observación como sin cambio, positiva (precalibración sin concordancia y poscalibración con concordancia) y negativa (precalibración con concordancia y poscalibración sin concordancia). En cada caso se calcularon la frecuencia para cada categoría, la frecuencia de concordancia entre cada alumno y el docente antes y después de la calibración, y la diferencia entre frecuencias. Resultados: La frecuencia absoluta de casos con concordancia alumno/docente sin cambios fue entre 65 y 85; con cambio positivo, entre 14 y 29; y con cambio negativo, entre 1 y 8. La concordancia antes y después de la calibración resultó entre 37% y 79,2%. Conclusión: La calibración mejoró parcialmente la capacitación de los alumnos para la evaluación radiográfica de los tratamientos endodónticos (AU)

Aim: To describe one experience of calibration in the radiographic evaluation of 100 endodontic treatments performed ex vivo in undergraduate students. Material and methods: One professor and 13 undergraduate students participated in this study, who independently radiographically evaluated 100 ex vivo endodontic treatments and determined whether each case was correct or incorrect. Later, the same professor presented a theoretical class to the students with other radiographic images in order to calibrate the difference between correct and incorrect treatments. Then the radiographs of the same 100 cases were projected and the students made a new evaluation. The frequency of agreement with the teacher was determined for each student in the 100 cases before and after the calibration. Each observation was categorized as without change, with positive change (pre-calibration without agreement and post-calibration with agreement) and with negative change (pre-calibration with agreement and post-calibration without agreement). The frequency for each category was calculated for each student. In each of the cases, the frequency of students in which concordances with the teacher were observed before and after calibration, and the difference between both frequencies were calculated. Results: The absolute frequency of cases with agreement of the students/teacher without changes varied between 65 and 85, with a positive change between 14 and 29 and a negative change between 1 and 8. The concordance before and after calibration varied between 37.0% and 79.2%. Conclusion: Calibration partially improved the training of students in radiographic evaluation of endodontic treatments (AU)

Imaging modalities to inform the detection and diagnosis of early caries.

BACKGROUND: The detection and diagnosis of caries at the earliest opportunity is fundamental to the preservation of tooth tissue and maintenance of oral health. Radiographs have traditionally been used to supplement the conventional visual-tactile clinical examination. Accurate, timely detection and diagnosis of early signs of disease could afford patients the opportunity of less invasive treatment with less destruction of tooth tissue, reduce the need for treatment with aerosol-generating procedures, and potentially result in a reduced cost of care to the patient and to healthcare services. OBJECTIVES: To determine the diagnostic accuracy of different dental imaging methods to inform the detection and diagnosis of non-cavitated enamel only coronal dental caries. SEARCH METHODS: Cochrane Oral Health's Information Specialist undertook a search of the following databases: MEDLINE Ovid (1946 to 31 December 2018); Embase Ovid (1980 to 31 December 2018); US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov, to 31 December 2018); and the World Health Organization International Clinical Trials Registry Platform (to 31 December 2018). We studied reference lists as well as published systematic review articles. SELECTION CRITERIA: We included diagnostic accuracy study designs that compared a dental imaging method with a reference standard (histology, excavation, enhanced visual examination), studies that evaluated the diagnostic accuracy of single index tests, and studies that directly compared two or more index tests. Studies reporting at both the patient or tooth surface level were included. In vitro and in vivo studies were eligible for inclusion. Studies that explicitly recruited participants with more advanced lesions that were obviously into dentine or frankly cavitated were excluded. We also excluded studies that artificially created carious lesions and those that used an index test during the excavation of dental caries to ascertain the optimum depth of excavation. DATA COLLECTION AND ANALYSIS: Two review authors extracted data independently and in duplicate using a standardised data extraction form and quality assessment based on QUADAS-2 specific to the clinical context. Estimates of diagnostic accuracy were determined using the bivariate hierarchical method to produce summary points of sensitivity and specificity with 95% confidence regions. Comparative accuracy of different radiograph methods was conducted based on indirect and direct comparisons between methods. Potential sources of heterogeneity were pre-specified and explored visually and more formally through meta-regression. MAIN RESULTS: We included 104 datasets from 77 studies reporting a total of 15,518 tooth sites or surfaces. The most frequently reported imaging methods were analogue radiographs (55 datasets from 51 studies) and digital radiographs (42 datasets from 40 studies) followed by cone beam computed tomography (CBCT) (7 datasets from 7 studies). Only 17 studies were of an in vivo study design, carried out in a clinical setting. No studies were considered to be at low risk of bias across all four domains but 16 studies were judged to have low concern for applicability across all domains. The patient selection domain had the largest number of studies judged to be at high risk of bias (43 studies); the index test, reference standard, and flow and timing domains were judged to be at high risk of bias in 30, 12, and 7 studies respectively. Studies were synthesised using a hierarchical bivariate method for meta-analysis. There was substantial variability in the results of the individual studies, with sensitivities that ranged from 0 to 0.96 and specificities from 0 to 1.00. For all imaging methods the estimated summary sensitivity and specificity point was 0.47 (95% confidence interval (CI) 0.40 to 0.53) and 0.88 (95% CI 0.84 to 0.92), respectively. In a cohort of 1000 tooth surfaces with a prevalence of enamel caries of 63%, this would result in 337 tooth surfaces being classified as disease free when enamel caries was truly present (false negatives), and 43 tooth surfaces being classified as diseased in the absence of enamel caries (false positives). Meta-regression indicated that measures of accuracy differed according to the imaging method (Chi2(4) = 32.44, P < 0.001), with the highest sensitivity observed for CBCT, and the highest specificity observed for analogue radiographs. None of the specified potential sources of heterogeneity were able to explain the variability in results. No studies included restored teeth in their sample or reported the inclusion of sealants. We rated the certainty of the evidence as low for sensitivity and specificity and downgraded two levels in total for risk of bias due to limitations in the design and conduct of the included studies, indirectness arising from the in vitro studies, and the observed inconsistency of the results. AUTHORS' CONCLUSIONS: The design and conduct of studies to determine the diagnostic accuracy of methods to detect and diagnose caries in situ are particularly challenging. Low-certainty evidence suggests that imaging for the detection or diagnosis of early caries may have poor sensitivity but acceptable specificity, resulting in a relatively high number of false-negative results with the potential for early disease to progress. If left untreated, the opportunity to provide professional or self-care practices to arrest or reverse early caries lesions will be missed. The specificity of lesion detection is however relatively high, and one could argue that initiation of non-invasive management (such as the use of topical fluoride), is probably of low risk. CBCT showed superior sensitivity to analogue or digital radiographs but has very limited applicability to the general dental practitioner. However, given the high-radiation dose, and potential for caries-like artefacts from existing restorations, its use cannot be justified in routine caries detection. Nonetheless, if early incidental carious lesions are detected in CBCT scans taken for other purposes, these should be reported. CBCT has the potential to be used as a reference standard in diagnostic studies of this type. Despite the robust methodology applied in this comprehensive review, the results should be interpreted with some caution due to shortcomings in the design and execution of many of the included studies. Future research should evaluate the comparative accuracy of different methods, be undertaken in a clinical setting, and focus on minimising bias arising from the use of imperfect reference standards in clinical studies.

O uso da tomografia computadorizada de feixe cônico no diagnóstico e no gerenciamento de insucesso endodôntico: relato de caso clínico / The use of cone beam computed tomography in the diagnosis and management of endodontic failure: clinical case report

Objetivo: descrever um caso clínico em que a tomografia computadorizada de feixe cônico (TCFC) foi utilizada para auxiliar no diagnóstico e no melhor gerenciamento de retratamento endodôntico. Relato de caso: uma paciente compareceu à clínica com queixa de uma fístula na região dos molares superiores do lado direito há aproximadamente dois meses. Radiograficamente, observou-se lesão periapical do elemento 17. Após a confirmação da necessidade do retratamento, a paciente relatou já ter feito duas intervenções endodônticas nesse elemento. Assim, optou-se por solicitar um exame de TCFC, para melhores diagnóstico e planejamento do caso. Ao avaliar a TCFC, verificou-se presença de lesão periapical extensa, presença de espaços vazios no canal mesiovestibular (MV) e palatino (P), cone de guta percha além do ápice no canal distovestibular (DV) e localização do canal mesiopalatino (MP), que não havia sido manuseado anteriormente, rompimento de cortical óssea vestibular e palatino. Após planejamento, a paciente foi submetida ao retratamento endodôntico. Foi realizada a desobstrução dos canais radiculares com remoção do cone ultrapassando no canal DV, localização do MP e instrumentação completa de todos os canais. O hidróxido de cálcio foi utilizado como medicamento intracanal entre as consultas. Ao observar a regressão da fistula e os canais sem presença de exsudato, realizou-se a obturação do canal radicular. Considerações finais: a TCFC permitiu a visualização de erros operatórios pertinentes ao caso durante os tratamentos endodônticos prévios, o que possibilitou a indicação de um novo tratamento endodôntico e a manutenção do dente na arcada dentária.(AU)

Objective: to describe a clinical case where cone beam computed tomography (CBCT) was used to assist in the diagnosis and better management of endodontic retreatment. Case report: the patient attended the clinic complaining of a fistula in the upper molar region on the right side for approximately two months. Radiographically, the presence of a periapical lesion of element 17 was observed. After confirming the need for retreatment, the patient reported having already undergone two endodontic interventions on this tooth. Thus, it was decided to request a CBCT exam for better diagnosis and case planning. When assessing the CBCT, there was the presence of extensive periapical lesion, presence of empty spaces in the mesiobuccal (MB) and palatal (P) canal, gutta percha cone beyond the apex in the distobuccal (DB) canal and location of the mesiopalatal (MP) canal - which had not been previously handled -, rupture of the cortex vestibular and palatal bone. After planning, the patient underwent endodontic retreatment. Then, all the previous filling material were removed, including the gutta-percha by passing into the DB canal, MP was localized and complete instrumentation of all root canals were done. Calcium hydroxide was used as an intracanal medication between appointments. When the regression of the fistula was observed and canals were without exudate, root canal filling was performed. Final considerations: the CBCT allowed the visualization of operative errors pertinent to the case during previous endodontic treatments, which allowed the indication of a new endodontic treatment and the maintenance of the tooth in the dental arch.(AU)

Intraoral radiograph anatomical region classification using neural networks.

PURPOSE: Dental radiography represents 13% of all radiological diagnostic imaging. Eliminating the need for manual classification of digital intraoral radiographs could be especially impactful in terms of time savings and metadata quality. However, automating the task can be challenging due to the limited variation and possible overlap of the depicted anatomy. This study attempted to use neural networks to automate the classification of anatomical regions in intraoral radiographs among 22 unique anatomical classes. METHODS: Thirty-six literature-based neural network models were systematically developed and trained with full supervision and three different data augmentation strategies. Only libre software and limited computational resources were utilized. The training and validation datasets consisted of 15,254 intraoral periapical and bite-wing radiographs, previously obtained for diagnostic purposes. All models were then comparatively evaluated on a separate dataset as regards their classification performance. Top-1 accuracy, area-under-the-curve and F1-score were used as performance metrics. Pairwise comparisons were performed among all models with Mc Nemar's test. RESULTS: Cochran's Q test indicated a statistically significant difference in classification performance across all models (p < 0.001). Post hoc analysis showed that while most models performed adequately on the task, advanced architectures used in deep learning such as VGG16, MobilenetV2 and InceptionResnetV2 were more robust to image distortions than those in the baseline group (MLPs, 3-block convolutional models). Advanced models exhibited classification accuracy ranging from 81 to 89%, F1-score between 0.71 and 0.86 and AUC of 0.86 to 0.94. CONCLUSIONS: According to our findings, automated classification of anatomical classes in digital intraoral radiographs is feasible with an expected top-1 classification accuracy of almost 90%, even for images with significant distortions or overlapping anatomy. Model architecture, data augmentation strategies, the use of pooling and normalization layers as well as model capacity were identified as the factors most contributing to classification performance.

Aplicación forense de tecnología radiográfica dental portátil en Argentina: estado actual y perspectivas futuras / Forensic application of portable dental radiographic technology in Argentina: current status and future prospects

Objetivos: Mensurar los niveles de radiación de fuga y dispersión emanada a través de los blindajes y estructuras plomadas del tubo de rayos X de la unidad dental portátil NOMAD, controlando la retrodispersión con el uso del escudo protector de acrílico plomado adaptado en el extremo final del tubo localizador plomado. Se midieron las tasas de exposición dispersadas mediante un detector tipo Geiger-Müller y una cámara de ionización con respuesta en el rango de energías aportadas en diagnóstico por imágenes para la medición de la exposición directa y determinación posterior de las dosis. Se utilizó un fantomas diseñado para diagnóstico odontológico, sopesando la radiación en diferentes angulaciones de operación del equipo NOMAD, simulando los gestos posturales de odontólogos, radiólogos y sujetos a identificar. Se controlaron las tasas de exposición para determinar los valores de las dosis aportadas en las zonas significativas corporales más radiosensibles del operador del equipo. Se obtuvo como resultado que la retrodispersión en el cristalino del ojo del operador fue significativamente menor cuando el fantomas estaba acostado, mientras que a nivel de gónadas resultó más baja con el cuerpo sentado. La tasa de dosis máxima de radiación dispersa que impactó en los operadores fue de 350.8 micro Sieverts por hora (uSv/h) en la zona de gónadas, por cada radiografía tomada sin el uso del delantal de goma plomada, reduciéndose a 4.38 micro Sieverts por hora (uSv/h) al utilizarlo (AU)

Uso de la ecografía como método diagnóstico y ayuda terapéutica en la práctica odontológica. Una revisión / Use of ultrasound as a diagnostic method and therapeutic tool in dental practice. A review

La ecografía es una ayuda diagnóstica en el área de la salud que se usa para evaluar el desarrollo intrauterino, observar el comportamiento de lesiones, valorar órganos internos y acompañar procedimientos clínicos específicamente en la medicina, pero en la odontología es un campo en el que apenas se está explorando e incursionando para incluirlo como parte de los métodos diagnósticos de rutina en la consulta clínica. El creciente interés por investigar su uso como método diagnóstico y terapéutico en la odontología se basa en las bondades que tiene y en cómo puede facilitar muchos procesos por tratarse de una ayuda diagnóstica accesible, económica y poco nociva para la salud. En el presente artículo se exponen los diferentes usos que se le da a la ecografía en las diferentes especialidades odontológicas, y se la compara con otros métodos diagnósticos. (AU)

In medicine, ultrasound is especially useful to evaluate intrauterine development, cyst behavior, and internal organs, but the use of ultrasound in dentistry has only recently been explored and used in the daily routine diagnostic methods in clinical dental practice. The growing interest in the use of ultrasound as a diagnostic and therapeutic method in dentistry has led to studies investigating its benefits in relation to accessibility, cost and innocuousness to health. This review describes the current use of ultrasound in different dental specialties and compares it with other diagnostic methods. (AU)

Niveles de Referencia para Diagnóstico en Procedimientos Radiológicos Dentales: Una Guía Práctica / Diagnostic Reference Levels in Dental Radiological Procedures: A Practical Guide

RESUMEN: Las exposiciones médicas con radiación ionizante son actualmente la principal fuente de exposición a la radiación artificial a nivel global, entre ellas, los exámenes dentales corresponden a uno de los más frecuentes. Para prevenir dosis innecesariamente altas a los pacientes durante estas exposiciones, la Comisión Internacional de Protección Radiológica (ICRP) recomienda la utilización de Niveles de Referencia para Diagnóstico (DRLs), como una herramienta efectiva de ayuda a la optimización de la protección radiológica en la exposición médica de pacientes. Dado que la legislación de Chile aún no ha incorporado el uso de los DRLs, el presente trabajo de revisión tuvo como objetivo analizar la publicación N° 135 de la ICRP para generar un documento que sirva de guía para los odontólogos, explicando de manera didáctica y en un lenguaje sencillo, pero técnico, los principales aspectos a tener en cuenta para establecer los DRLs en procedimientos de radiología dental.

SUMMARY: Currently exposure to ionizing radiation is currently the main source of exposure to artificial radiation worldwide, with dental examinations being one of the most frequent events. In order to prevent exposure of unnecessarily high doses in patients, the International Commission on Radiological Protection (ICRP) recommends the use of Diagnostic Reference Levels (DRLs), as an effective tool to help maximize protection from radiation during medical exposure of patients. Given that the Chilean legislation has not yet incorporated the use of DRLs, the purpose of this study was to analyze publication N° 135 of the ICRP to generate a document, to serve as a guide for dentists, didactically outlining in simple but technical language, the main aspects to consider when establishing DRLs in dental radiology procedures.