Associated risks with periodontal x-rays or CBCT scans: Are there any?

Periodontal and implant radiography, mainly including intra-oral peri-apical and cone beam computed tomography images, are crucial in the diagnosis and treatment planning process. However, radiation safety concerns have been a chronic concern over the years, leading to uncomfortable situations. It is therefore crucial to understand the actual radiation exposure to determine if the patients' fear of necessary diagnostic exams is justified. In this perspective article, we aimed to provide concise information on dental imaging exposure, risks, and benefits, comparing them to that of absorbed radiation from daily life activities; and secondarily, to help periodontists choose the best option for each case and become more confident in addressing patients' concerns and providing a summary of safety guidelines as a reference for them.

Ambient light exposure of photostimulable phosphor plates: is there a safe limit for acceptable image quality?

OBJECTIVES: To subjectively assess radiographs obtained with photostimulable phosphor (PSP) plates exposed to clinical levels of ambient light prior to read-out to potentially set a safe limit for acceptable image quality. METHODS AND MATERIALS: Six dental regions of a dry human skull were X-rayed using PSP plates from VistaScan and Express under four exposure times: 0.1, 0.2, 0.32, and 0.4 s. Before read-out, the PSP plates were exposed to ambient light for 0, 5, 10, 30, 60, and 90 s. Six observers were asked to classify the 288 resulting radiographs as acceptable or unacceptable based on the identification of anatomical structures and global image quality. The number of answers classifying radiographs as unacceptable was used to calculate a rejection rate; a pairwise comparison for better image quality was further conducted among radiographs considered acceptable. Reproducibility was tested by having 25% of all experimental groups reassessed. RESULTS: Intra- and interobserver agreement ranged from 0.87 to 1.00 and from 0.81 to 0.92, respectively. Exposure of PSP plates to ambient light increased rejection rates mostly as of 10 s. In the pairwise comparison, subtle differences were observed between radiographs obtained with PSP plates not exposed and those exposed to ambient light for 5 s. CONCLUSIONS: Ambient light exposure of PSP plates impairs the image quality of radiographs. A safe limit of ambient light exposure of 5 s for VistaScan and Express should be considered. Ambient light exposure of PSP plates within safe limits can avoid retakes and reduce unnecessary patient exposure to X-rays.

The diagnostic performance of the Java-based software colorization tool in the diagnosis of dental caries: an in vitro study.

OBJECTIVE: This in vitro study aimed to compare the diagnostic outcomes of caries detection in premolar and molar teeth on digital periapical radiographs viewed as grayscale images and in the Java-based software (JBS) pseudocolor spectrum. METHOD AND MATERIALS: The study comprised 92 premolar or molar human teeth (n = 46 with caries and n = 46 without clinical caries). For each tooth, digital periapical radiographic images (DPRIs), JBS pseudocolor images, and stereomicroscope images were collected, and caries presence and depth were recorded. In JBS pseudocolor images, regions of interest (ROIs) were detected, and ROI values for caries area (ROI1), non-caries area (ROI2), mesial area (ROI3), and distal area (ROI4) were obtained. The degree of inter-observer agreement was determined using the kappa coefficient, and the sensitivity and specificity of the methods were assessed using ROC analysis. RESULTS: While neither method was consistent with stereomicroscopy in determining caries depth (P < .005), for both observers the kappa value of JBS pseudocolor images were slightly higher than those for DPRIs. ROI1 was found to be significantly lower than ROI2 (P < .001), whereas no difference was found between ROI3 and ROI4 (P = .877). For both observers, the sensitivity and specificity obtained from JBS pseudocolor were above 89%. CONCLUSION: JBS pseudocolor images can be used for caries detection and offer high sensitivity and specificity.

How Does Ambient Light Affect the Image Quality of Phosphor Plate Digital Radiography? A Quantitative Analysis Using Contemporary Digital Radiographic Systems.

The aim of this study is to quantitatively evaluate the influence of the duration of ambient light exposure on the image quality of digital radiographs obtained with contemporary phosphor plate (PSP)-based systems. Radiographs of an aluminum step-wedge were obtained using VistaScan and Express systems at five X-ray exposure times: 0.10, 0.20, 0.32, 0.40, and 0.50 s; the resulting dose-area products were, respectively, 21.93, 43.87, 70.19, 87.75, and 109.6 mGycm2. Before PSP read-out, half of the sensitive surface of the PSP plates was exposed to ambient light for 5, 10, 30, 60, and 90 s. The effect of light exposure on brightness, contrast, contrast-to-noise ratio (CNR), signal-to-noise ratio (SNR), and image saturation was compared using ANOVA with the Tukey test (α = 0.05). Ambient light exposure increased brightness and contrast and reduced CNR and SNR in PSP-based radiographs of contemporary digital systems. At the longest X-ray exposure times, ambient light exposure reduced the dark saturation (mean gray values ≤ 1) observed in Express. In conclusion, the negative effects of ambient light observed on the image quality of PSP-based radiographs are directly proportional to the duration of exposure. Clinicians should be aware of such harmful effects when handling and scanning PSP plates in bright environments.

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.

Efficacy of digital radiography for detecting a second mesiobuccal canal adjacent to unfilled or filled canals.

The aim of this study was to assess the diagnostic accuracy of digital periapical radiography for the detection of the second mesiobuccal (MB2) canal when the adjacent canals are unfilled or filled with gutta percha. Forty human maxillary first molars were selected, 20 of which had an MB2 canal. The presence or absence of the MB2 canal was confirmed using microcomputed tomography. Digital periapical radiographs of each tooth were obtained from 3 horizontal angles before and after the adjacent root canals were filled with gutta percha. Three experienced oral radiologists evaluated all images and indicated the presence or absence of the MB2 canal using a confidence scale of 5 points. To assess intraobserver and interobserver agreement, weighted kappa coefficients were calculated. The diagnostic test (sensitivity, specificity, and accuracy) and area under the receiver operating characteristic curve (Az) values were calculated and compared between groups (n = 40): radiographs of the first molars with unfilled adjacent canals and radiographs of the same teeth with filled adjacent canals. For all observers, intraobserver reproducibility ranged from substantial (0.70) to almost perfect (0.86), and interobserver reproducibility ranged from fair (0.39) to substantial (0.67). Similar values of specificity and Az for the detection of the MB2 canal were observed with unfilled and filled adjacent canals. The sensitivity and accuracy were slightly greater when the adjacent root canals were filled with gutta percha. Detection of the MB2 canal on digital periapical radiographs can be challenging even when obtained at varying horizontal angles, and the presence of gutta percha does not influence the detection.

Radiographic Diagnosis of Simulated External Root Resorption in Multi-Rooted Teeth: The Influence of Spatial Resolution.

The aim of this study was to evaluate the influence of spatial resolution (line pairs per millimetre - lp/mm) on the diagnosis of simulated external root resorption (ERR) in multi-rooted teeth by using digital periapical radiography. Forty human mandibular molars (80 roots) were used. The roots were divided into the following groups (n = 10): control without root filling (WORF), control with root filling (WRF), small ERRWORF, small ERR-WRF, moderate ERR-WORF, moderate ERR-WRF, extensive ERR-WORF and extensive ERR-WRF. Four digital radiographs (phosphor storage plates - PSP system) were taken of each tooth in three angulations. The PSPs were scanned with 10, 20, 25 and 40 lp/mm. All images were assessed by three endodontists who used a five-point scale for presence and absence of ERR and classified its location (cervical, middle or apical third). ROC curves and one-way ANOVA were performed (p < 0.01). Diagnosis of ERR in nonroot-filled teeth showed higher values of sensitivity for 20 lp/mm and higher values of both specificity and accuracy for 40 lp/mm. In root-filled teeth, sensitivity and accuracy were higher for 25 lp/mm and spatial resolution had no influence on specificity. The best resolution for diagnosis of small and extensive ERR was 25 lp/mm, whereas for moderate ERR, it was 40 lp/mm. Cervical ERR was the most difficult to diagnose, regardless of the spatial resolution. Higher spatial resolutions have improved the radiographic diagnosis of simulated ERR in multi-rooted teeth and this should be considered when performing digital radiographs.

O objetivo deste estudo foi avaliar a influência do número de pares de linhas em radiografia intra-oral digital, na precisão da detecção de reabsorção radicular externa. Quarenta molares inferiores (n=80 raízes) foram submetidos ao preparo químico mecânico e em então, metade da amostra foi obturada. Em seguida, as raízes dos dentes foram aleatoriamente divididas de acordo com o tamanho da reabsorção radicular a ser simulada e com a presença e ausência de tratamento endodôntico. As RRE foram realizadas com brocas esféricas diamantadas de tamanhos 1/2, 1, 2. Executou-se radiografias digitais por meio do sistema de aquisição semidireto com a utilização de placas de fósforo fotoestimuladas (PSP). Em cada dente, incidências orto, mésio e distorradial foram repetidas quatro vezes, para que pudessem ser digitalizadas com resoluções de 10, 20, 25, 40 pl/mm. Após análise, verificou-se que dentes obturados apresentaram menores valores de sensibilidade com 10, 20 e 25 pl/mm e maiores valores de especificidade e acurácia para as mesmas resoluções. Dentes sem obturação registraram maiores valores de sensibilidade para resolução 20 e menor para 40; no entanto, a especificidade e a acurácia, foram maiores com 40 e menores em 10. Em RRE pequena, as resoluções 10 e 25 pl/mm foram respectivamente menos e mais acuradas; RRE média, foi maior com 40 pl/mm e RRE grandes foram melhores identificadas com 25. Correlacionando acertos no diagnóstico com localização das RRE, verificou-se que o terço cervical apresentou-se menos detectável. Concluiu-se que resolução espacial influenciou a detecção de RRE simuladas em radiografias periapicais digitais.

Radiographic Diagnosis of Simulated External Root Resorption in Multi-Rooted Teeth: The Influence of Spatial Resolution / Diagnóstico radiográfico de reabsorção externa simulada em dentes multiradiculares: influência da resolução especial

ABSTRACT The aim of this study was to evaluate the influence of spatial resolution (line pairs per millimetre - lp/mm) on the diagnosis of simulated external root resorption (ERR) in multirooted teeth by using digital periapical radiography. Forty human mandibular molars (80 roots) were used. The roots were divided into the following groups (n = 10): control without root filling (WORF), control with root filling (WRF), small ERRWORF, small ERRWRF, moderate ERRWORF, moderate ERRWRF, extensive ERRWORF and extensive ERRWRF. Four digital radiographs (phosphor storage plates - PSP system) were taken of each tooth in three angulations. The PSPs were scanned with 10, 20, 25 and 40 lp/mm. All images were assessed by three endodontists who used a fivepoint scale for presence and absence of ERR and classified its location (cervical, middle or apical third). ROC curves and oneway ANOVA were performed (p < 0.01). Diagnosis of ERR in nonrootfilled teeth showed higher values of sensitivity for 20 lp/mm and higher values of both specificity and accuracy for 40 lp/mm. In rootfilled teeth, sensitivity and accuracy were higher for 25 lp/mm and spatial resolution had no influence on specificity. The best resolution for diagnosis of small and extensive ERR was 25 lp/mm, whereas for moderate ERR, it was 40 lp/mm. Cervical ERR was the most difficult to diagnose, regardless of the spatial resolution. Higher spatial resolutions have improved the radiographic diagnosis of simulated ERR in multirooted teeth and this should be considered when performing digital radiographs.

RESUMO O objetivo deste estudo foi avaliar a influência do número de pares de linhas em radiografia intraoral digital, na precisão da detecção de reabsorção radicular externa. Quarenta molares inferiores (n=80 raízes) foram submetidos ao preparo químico mecânico e em então, metade da amostra foi obturada. Em seguida, as raízes dos dentes foram aleatoriamente divididas de acordo com o tamanho da reabsorção radicular a ser simulada e com a presença e ausência de tratamento endodôntico. As RRE foram realizadas com brocas esféricas diamantadas de tamanhos 1/2, 1, 2. Executouse radiografias digitais por meio do sistema de aquisição semidireto com a utilização de placas de fósforo fotoestimuladas (PSP). Em cada dente, incidências orto, mésio e distorradial foram repetidas quatro vezes, para que pudessem ser digitalizadas com resoluções de 10, 20, 25, 40 pl/mm. Após análise, verificouse que dentes obturados apresentaram menores valores de sensibilidade com 10, 20 e 25 pl/mm e maiores valores de especificidade e acurácia para as mesmas resoluções. Dentes sem obturação registraram maiores valores de sensibilidade para resolução 20 e menor para 40; no entanto, a especificidade e a acurácia, foram maiores com 40 e menores em 10. Em RRE pequena, as resoluções 10 e 25 pl/mm foram respecti vamente menos e mais acuradas; RRE média, foi maior com 40 pl/mm e RRE grandes foram melhores identificadas com 25. Correlacionando acertos no diagnóstico com localização das RRE, verificouse que o terço cervical apresentouse menos detectável. Concluiuse que resolução espacial influenciou a detecção de RRE simuladas em radiografias periapicais digitais.

Diagnostic accuracy of panoramic radiography and ultrasonography in detecting periapical lesions using periapical radiography as a gold standard.

OBJECTIVES: The purpose of this study was to compare the accuracy of imaging techniques in diagnosing periapical lesions. METHODS: Imaging records of 80 patients (51 females, 29 males, aged between 14 and 75 years) including periapical and panoramic radiographs and ultrasonographic images were selected from databases of Selcuk University Dentistry Faculty. Periapical radiographs were accepted as gold-standard and 160 anterior maxillary and mandibular teeth with or without periapical lesion were included to the study. Three specialist observers (dental radiologists) evaluated the presence and appearance of periapical lesions on panoramic radiograph and ultrasonographic images.Sensitivity, specificity, positive predictive value, negative predictive value and diagnostic value of panoramic radiographs and ultrasonography were determined. RESULTS: Sensitivity was 0.80 and 0.77 for ultrasonographic images and panoramic radiographs, respectively which shows that periapical lesion was correctly detected in 80% of the cases with ultrasound and in 77% of the cases with panoramic radiography. Specificity values were determined as 0.97 for ultrasound and 0.95 for panoramic radiography. Overall diagnostic accuracy was 0.86 and 0.84 for ultrasound and panoramic radiography, respectively. CONCLUSIONS: Periapical and panoramic radiographs are commonly used to visualize periapical lesions. Besides, ultrasonography is an alternative method to digital radiographic techniques in the diagnosis of anterior teeth with periapical lesions.

Influência do tipo de compósito e tempo de exposição aos raios-x na produção de artefatos radiográficos em modelos de restauração classe II / Influence of the type of composite and time of exposure to x-rays on the production of radiographic artifacts in class II restoration models

Objetivo: Avaliar o efeito do tempo de exposição e do tipo de compósito na produção de artefato radiográfico na interface dente/material restaurador. Materiais e Métodos: Em 20 incisivos bovinos hígidos foram feitos preparos cavitários e restaurações classe II utilizando resinas compostas Filtek Bulk Fill One (gruo 1) e a Filtek Z350 (grupo 2). Em seguida, os dentes foram expostos para obtenção das radiografias digitais, variando o tempo de exposição em 0,07, 0,10, 0,14, 0,20 e 0,25s. As imagens foram avaliadas para investigação da presença de artefato através da análise do número de pixels modificado (QPXD) e do valor médio de cinza nas restaurações de classe II (MGVR), utilizando o software Image J (Instituto Nacional de Saúde, Bethesda, MD, EUA). Resultados: Observou-se a presença de artefato em toda amostra avaliada, independente de tipo de material restaurador e tempo de exposição empregado. Não se observou diferença estatisticamente significante na QPXD e nos MGVR entre as resinas utilizadas (ANOVA 2 fatores, p p>0,05). A análise do MGVR indicou que não houve diferenças estatisticamente significativas entre as resinas nem entre os tempos de exposição (p>0,05). Observou-se uma correlação entre a QPXD e o MGVR (r=0,29) para a resina Filtek Bulk Fill One. Conclusão: Foi identificado a presença de pixels alterados sobre a dentina na região da interface dente-restauração em todos os corpos de prova. A variação do tempo de exposição como também o tipo do compósito restaurador não influenciou no aumento ou diminuição do QPXD e nem tão pouco no MGVR. Contudo houve correlação entre o QPXD e o MGVR para a resina Filtek Bulk Fill One. Pesquisas adicionais são necessárias para determinar se o QPXD representa um artefato verdadeiro ou desajuste do material restaurador ou deficiência na aplicação sistema adesivo (AU).

Objective: To evaluate the effect of the exposure time and the type of composite in the production of radiographic artifact at the tooth / restorative interface. Materials and Methods: In 20 healthy bovine incisors, cavity preparations and class II restorations were made using composite resins Filtek Bulk Fill One (group 1) and Filtek Z350 (group 2). Then, the teeth were exposed to obtain digital radiographs, varying the exposure time by 0.07, 0.10, 0.14, 0.20 and 0.25s. The images were evaluated for investigation of the presence of artifact through the analysis of the modified number of pixels (QPXD) and the average gray value in class II (MGVR) restorations, using the Image J software (National Health Institute). Results: The presence of artifact was observed in all evaluated samples, regardless of the type of restorative material and the exposure time employed. There was no statistically significant difference in QPXD and MGVR between the resins used (ANOVA 2 factors, p p> 0.05). The MGVR analysis indicated that there were no statistically significant differences between resins or between exposure times (p> 0.05). There was a correlation between QPXD and MGVR (r = 0.29) for Filtek Bulk Fill One resin. Conclusion: The presence of altered pixels on dentin in the region of the tooth-restoration interface was identified in all specimens. The variation in the exposure time as well as the type of the restorative composite did not influence the increase or decrease of QPXD and neither in MGVR. However, there was a correlation between QPXD and MGVR for Filtek Bulk Fill One resin. Further research is needed to determine whether QPXD represents a true artifact or misfit of the restorative material or deficiency in the adhesive system application (AU).

Evaluation of the effect of the inversion filter on enhancing the visibility of the mandibular incisive canal in comparison with the original images.

BACKGROUND: The mandibular incisive canal (MIC) is a neural canal containing one of the lower branches of the inferior alveolar nerve, called the mandibular incisive nerve, which can get damaged and cause complications during the removal of bone from the interforaminal region. OBJECTIVES: The aim of this study was to determine the effect of the inversion filter (IF) on improving the visibility of MIC as compared to the original images. MATERIAL AND METHODS: In this retrospective, descriptive, analytical study, 343 samples of digital panoramic radiography were examined. The images were analyzed with and without IF. The frequency and confidence intervals (CIs) of identifying MIC were used to determine its visibility, both with IF and in the original images. Besides, the difference between the maximum and minimum diameters of the canal as well as the distance from MIC to the alveolar crest and to the mental foramen were examined. For statistical analysis, McNemar's test and the paired t-test were used, and the concordance was calculated using the kappa coefficient. RESULTS: No significant differences were found in the prevalence of the incisive canal, or in its unilateral or bilateral visibility between the original and filtered radiography in this study (p = 0.42 and p = 0.67, respectively). The absolute values of the interval difference between MIC and the mental foramen, the maximum and minimum diameters of MIC, and the distance from MIC to the alveolar crest were statistically significant between the filtered and original radiography, although the difference was clinically unimportant. CONCLUSIONS: The use of IF produced results similar to the original radiography; its application neither increased the clarity nor improved the visibility of the incisive canal.

A comparison of perceived diagnostic image quality in direct digital panoramic images between standard and advanced external GOP image processing.

Objective: The objective of the present study was to study the effect of adaptive image processing (GOP processing) on the visibility of anatomical structures in direct digital panoramic images. Material and methods: The study comprised panoramic images of 50 consecutive adult individuals aged 18-60 years. Nine dentists working with dental radiology compared the structural image quality of all standard-processed and GOP-processed panoramic images for six anatomical structures, using a six-point scale for visual grading characteristics analysis. Results: For all anatomic structures a statistically significant difference in favour of the GOP was found. Conclusions: The present study shows that it is possible to improve perceived diagnostic image quality of direct digital panoramic radiography using GOP technology compared to the manufacturers' standard processing. Manufacturers' image-processing programs can be further developed, as there is a possibility of improving the perceived diagnostic content of an image with external processing.

Dentists' use of digital radiographic techniques: Part II - extraoral radiography: a questionnaire study of Swedish dentists.

OBJECTIVE: The present study aims to gain knowledge about the dentist's use and choice of digital extraoral imaging methods, panoramic radiography and cone beam computed tomography (CBCT). MATERIALS AND METHODS: A questionnaire sent to 2481 dentists within the Swedish Dental Society contained questions about the panoramic technique and CBCT technique used, education, clinic size and type of service. The response rate was 53%. RESULTS: The study showed that 61% of the Swedish dentists had access to panoramic techniques and that 84% used a direct digital sensor, while 6% used storage phosphor plate techniques. Around 8% of the Swedish dentists had access to CBCT. It was also observed that group practices had two times higher odds of having panoramic equipment compared with solo practices. Approximately 40% of the dentists had undergone postgraduate education in oral radiology during the last 5 years. Dental nurses and dental hygienists exposed 92% of the panoramic radiographs and 75% of the CBCTs. Thirty per cent of those clinics with access to a panoramic unit exposed >30 panoramic radiographs per month and 56% of the clinics having access to CBCT did more than 75 examinations per year. CONCLUSIONS: Today 61% of Swedish dentists have access to panoramic radiography and 8% have access to CBCT. There is a greater likelihood of having access if the dentist works in the public dental health service or in a group practice and if the dentist has undergone any postgraduate course in oral radiology.

Importância pericial na análise da radiopacidade de resinas compostas por meio de sistema radiográfico digital / Forensic importance in the analysis of composite radiopacity using digital radiograph system

Introdução: A análise da radiopacidade nos exames radiográficos é importante ao cirurgião-dentista não apenas para a diferenciação entre estruturas dentais e material restaurador, mas também para verificação de infiltrações marginais e do diagnóstico de cáries secundárias ou recorrentes. Além de sua importância clínica, a diferenciação de materiais restauradores por sua radiopacidade apresenta potencial no âmbito forense, uma vez que pode auxiliar no processo de identificação humana. Objetivo: Este estudo teve como objetivo avaliar a radiopacidade das resinas compostas fotopolimerizáveis Tetric N Ceram, Z100, Z250 e Z350 por meio de radiografia digital. Métodos: Foi realizado um estudo experimental in vitro com 16 corpos de prova medindo 2x4mm. Foi usada uma escala de alumínio com 9 degraus (com 1 mm de espessura cada) para comparação dos valores da escala dinâmica encontrados por meio das imagens digitais geradas no sistema digital radiográfico indireto. Foram feitas 12 leituras para cada resina avaliada e para cada um dos sete degraus da escala de alumínio em três datas diferentes. Para verificar qual dos degraus da escala de alumínio representaria os valores obtidos pelas resinas individualmente, os valores foram comparados com aqueles obtidos em cada degrau. Resultados: A resina Tetric mostrou maior similaridade com o degrau 1 da escala de alumínio, ou seja, o mais radiopaco. A resina Z100 apresentou valores próximos com o degrau 3. Os valores da resina Z250 apresentaram variabilidade entre os degraus 3 e 4, porém não mostrou correlação com os mesmos. A resina Z350 apresentou correlação muito boa, inversa e significativa com os degraus 3 e 4. Conclusão: Cada resina analisada apresentou características de radiopacidade singulares, que potencialmente viabilizam o auxilio a Odontologia Legal frente à necessidade de identificação humana. Em específico, a resina Tetric apresentou maior radiopacidade. Ainda assim, as resinas Z100, Z250 e Z350 apresentaram radiopacidade dentro dos padrões esperados (exigidos pela ISO 4049). Estudos futuros são necessários com outras resinas compostas para compreender melhor o potencial desta pesquisa para propósitos forenses.

Introduction: The analysis of radiopacity in radiographic exams is important for dentists not only for the differentiation between dental structures, but also for the assessment of infiltration in dental restorations and the diagnosis of dental caries. Besides the clinical significance, the differentiation of restorative materials based on their radiopacity is potentially useful in Forensic Odontology because it may support the human identification process. Objective: This study aimed to assess the radiopacity of the composites Tetric N Ceram, Z100, Z250 and Z350 through digital radiographs. Methods: An experimental in vitro study was performed with 16 test samples measuring 2x4mm. An aluminum scale with 9 levels (thickness of 1mm for each level) was used as a comparative source in face of the radiopacity levels detected for the composites in the digital radiograph system. The radiopacity of each composite and each level of the scale was analyzed 12 times, in 3 different moments. The radiopacity values obtained between the scale and the composites were statistically associated to indicate which scale level represents better the composite analyzed. Results: The composite Tetric corresponded to the scale level 1 (the most radiopaque). The composite Z100 presented values closer to the scale level 3. The composite Z250 ranged between levels 3 and 4, but did not presented statistical association. The composite Z350 presented statistical association with scale levels 3 and 4. Conclusion: Each composite presented distinct characteristics of radiopacity that could possibly contribute to the human identification process in Forensic Odontology. In specific, the composite Tetric had the highest radiopacity value. Despite less radiopaque, the composites Z100, Z250 and Z350 presented values within the standards expected (required by ISO 4049). Future studies are necessary with other composites in order to understand better the potential application for forensic purposes.

Diagnosis of alveolar and root fractures: an in vitro study comparing CBCT imaging with periapical radiographs

Abstract Objective To compare periapical radiograph (PR) and cone-beam computed tomography (CBCT) in the diagnosis of alveolar and root fractures. Material and Methods Sixty incisor teeth (20 higid and 40 with root fracture) from dogs were inserted in 60 anterior alveolar sockets (40 higid and 20 with alveolar fracture) of 15 macerated canine maxillae. Each fractured socket had a root fractured tooth inserted in it. Afterwards, each maxilla was submitted to PR in two different vertical angulation incidences, and to CBCT imaging with a small field of view (FOV) and high-definition protocol. Images were randomized and posteriorly analyzed by two oral and maxillofacial radiologists two times, with a two-week interval between observations. Results Sensitivity and specificity values were good for root fractures for PR and CBCT. For alveolar fractures, sensitivity ranged from 0.10 to 0.90 for PR and from 0.50 to 0.65 for CBCT. Specificity for alveolar fractures showed lower results than for root fractures for PR and CBCT. Areas under the ROC curve showed good results for both PR and CBCT for root fractures. However, results were fair for both PR and CBCT for alveolar fractures. When submitted to repeated measures ANOVA tests, there was a statistically significant difference between PR and CBCT for root fractures. Root fracture intraobserver agreement ranged from 0.90 to 0.93, and alveolar fracture intraobserver agreement ranged from 0.30 to 0.57. Interobserver agreement results were substantial for root fractures and poor/fair for alveolar fractures (0.11 for PR and 0.30 for CBCT). Conclusion Periapical radiograph with two different vertical angulations may be considered an accurate method to detect root fractures. However, PR showed poorer results than CBCT for the diagnosis of alveolar fractures. When no fractures are diagnosed in PR and the patient describes pain symptoms, the subsequent exam of choice is CBCT.

Assessment of three methods of geometric image reconstruction for digital subtraction radiography.

OBJECTIVES: To evaluate three methods of geometric image reconstruction for digital subtraction radiography (DSR). METHODS: Digital periapical radiographs were acquired of 24 teeth with the X-ray tube at 6 different geometric configurations of vertical (V) and horizontal (H) angles: V0°H0°, V0°H10°, V10°H0°, V10°H10°, V20°H0° and V20°H10°. All 144 images were registered in pairs (Group V0°H0° + 1 of the 6 groups) 3 times by using the Emago(®) (Oral Diagnostic Systems, Amsterdam, Netherlands) with manual selection and Regeemy with manual and automatic selections. After geometric reconstruction on the two software applications under different modes of selection, all images were subtracted and the standard deviation of grey values was obtained as a measure of image noise. All measurements were repeated after 15 days to evaluate the method error. Values of image noise were statistically analyzed by one-way ANOVA for differences between methods and between projection angles, followed by Tukey's test at a level of significance of 5%. RESULTS: Significant differences were found between most of the projection angles for the three reconstruction methods. Image subtraction after manual selection-based reconstruction on Regeemy presented the lowest values of image noise, except on group V0°H0°. The groups V10°H0° and V20°H0° were not significantly different between the manual selection-based reconstruction in Regeemy and automatic selection-based reconstruction in Regeemy methods. CONCLUSIONS: The Regeemy software on manual mode revealed better quality of geometric image reconstruction for DSR than the Regeemy on automatic mode and the Emago on manual mode, when the radiographic images were obtained at V and H angles used in the present investigation.

Reproducibility between conventional and digital periapical radiography for bone height measurement / Concordancia entre la radiografía periapical convencional y digital para medición de la altura ósea

Background. Several diagnostic aids are available for bone height measurement. Digital and conventional radiographs are the two ones most used in Dentistry. Few studies accounting for accuracy and precision have been conducted to compare these methods. Objective. The aim of this study was to estimate reproducibility between conventional and digital periapical radiography in bone height measurement in patients with chronic periodontitis. Methods. a consistency diagnostic test study was performed. 136 patients with chronic periodontitis were included, selecting the worst prognosis teeth and two radiographs -conventional and digital- were taken for each one. Two experienced and blinded examiners performed radiographic measurements. Reproducibility was obtained through Lin's concordance correlation coefficient by using the statistical package STATA™ for Windows. Results. Average age was 38.8 (SD: 9.9) and 61.6 % were female patients. 125 pairs of matched radiographs for 1000 measurements were evaluated. Overall reproducibility between the methods for mesial and distal measurements were 0.62 (95% CI: 0.55-0.70) and 0.64 (95% CI: 0.57-0.71) respectively. Conclusions. Reproducibility between methods was considered poor, including subgroup analysis, therefore, reproducibility between methods is minimal. Usage of these methods in periodontics should be made implementing the whole knowledge of the technical features and the advantages of these systems.

Antecedentes. Diversas ayudas diagnósticas están disponibles para la medición de la altura ósea; las dos más empleadas en odontología son la radiografía periapical convencional y la digital. A la fecha se cuenta con pocos estudios que den cuenta de la precisión y exactitud al compararlos. Objetivo. Estimar la concordancia entre la radiografía periapical convencional y la digital para la medición de la altura ósea en pacientes con periodontitis crónica. Métodos. Se realizó un estudio de pruebas diagnósticas de consistencia en 136 pacientes con periodontitis crónica seleccionando el diente con peor pronóstico. Se obtuvieron dos radiografías -convencional y digital- para cada diente y dos examinadores cegados realizaron las mediciones radiográficas. La concordancia se obtuvo con el coeficiente de correlación y concordancia de Lin empleando el paquete Stata para Windows. Resultados. La edad promedio fue 38.8 años (DE: 9.9) y 61.6% de los pacientes fueron mujeres. Se evaluaron 125 pares de radiografías para 1000 mediciones en total. La concordancia global fue 0.62 (IC 95%: 0.55-0.70) y 0.64 (IC 95%: 0.57-0.71) para las mediciones mesiales y distales respectivamente. Conclusiones. La concordancia entre los métodos se consideró pobre incluso en el análisis por subgrupos por tanto la reproducibilidad es mínima. El uso de estos métodos en periodoncia debe hacerse empleando el conocimiento completo de las características técnicas y ventajas de estos sistemas.

Evaluation of the reliability of measurements in cephalograms generated from cone beam computed tomography.

OBJECTIVE: The purpose was to compare angular and linear measurements generated in digital cephalometric radiographs and cephalograms synthesized from three-dimensional images. METHODS: Twenty-six individuals (12 men and 14 women) with mean age of 26.3 years were selected. Digital cephalometric radiographs and CBCTs were taken on the same day. The images were imported and analyzed on Dolphin Imaging V.10.5 software, which synthesized cephalograms in perspective projection and magnification of 9.7%. A single observer marked the points and repeated the procedure with an interval of time of ten days to evaluate intraexaminer error. In the statistical analysis paired Student's t test was used to establish the correlation between the measurements. RESULTS: The angular measurements GoGn.SN and IMPA, which involved the Gonial point (Go) and the linear measurements that involved the lips presented significant difference (p < 0.05). The other measurements presented good correlation. CONCLUSIONS: The measurements in the synthesized cephalograms proved to be reliable.

The evolution of cephalometric diagnosis in orthodontics.

INTRODUCTION: Although the development of CT have represented a landmark in diagnostic imaging, its use in Dentistry turned out very discretely over the years. With the appearance of programs for analysis of three-dimensional images, specific for Orthodontics and Orthognathic surgery, a new reality is being built. OBJECTIVE: The authors of this study aim to inform the orthodontic society of fundamentals about digital cephalometric radiographic image and computed tomography, discussing about: Field of view (FOV), radiation doses, demands for the use in Orthodontics and radiographic simulations.