Measurement of the mandibular canal and mandibular incisive canal using cone beam tomography in adults from South Brazil.

PURPOSE: To identify and measure the distance from the dental apices to the mandibular (MC) and mandibular incisive (MIC) canals, the diameter of the MC and the distances of the mental foramen (MF). METHODS: In this retrospective study, cone-beam computed tomography scans of 144 adult patients (males and females) from a dental school in South Brazil were evaluated. Cross-sections were selected on the MC and the MIC paths, perpendicular to the mandibular base, and measurements were taken from the dental apices to the mandibular cortices. The measurement and location of the mandibular and mental foramen on both sides were compared. Paired t-tests compared sides, while Student's t-tests compared sexes (P < 0.05). RESULTS: The distance from the dental apices to the upper wall of the MC was closest in the third molar and farthest in the central incisor region. In both sexes and sides, the path of the MC is in most cases lingually in the molar regions and moves to the buccal region from the second premolar. The MF emerges in the regions between the premolars or near the second premolar. CONCLUSION: The results of this study highlight the importance of evaluating specific individual characteristics of a given population.

Efectividad de los desinfectantes Lysol® y Amonio Cuaternario durante la evaluación de tres áreas críticas del sillón odontológico / Antimicrobial effectiveness of Lysol® and quaternary ammonium during evaluation of three critical areas of the dental chair

Objetivo. Determinar la eficacia antimicrobiana de Lysol® y amonio cuaternario durante la evaluación de tres áreas críticas de la unidad dental (bandeja / botones de mando, respaldo del sillón odontológico y mango de la jeringa triple). Métodos. A través de un estudio experimental comparativo transversal, se analizó un universo de 8 sillones dentales: tres fueron desinfectadas con Lysol®; tres con amonio cuaternario; dos sillones se seleccionaron como controles (positivo y negativo). Todos los sillones odontológicos se muestrearon dos veces día: antes de comenzar y al finalizar su uso, durante tres días. La toma de muestras fue realizada en las Clínicas de la Universidad Hemisferios antes y después de la colocación del desinfectante; las muestras fueron transportadas en caldo de tioglicolato para ser analizadas. Se sembraron diluciones 1:2 y 1:10 de cada muestra en Agar Plate Count y se incubaron por 24 horas a 37°C. Posteriormente, se realizó un recuento de colonias por duplicado, analizándose un total de 864 muestras. Resultados. Lysol® y amonio cuaternario 5% mostraron igual efectividad antimicrobiana ante las tres áreas analizadas (p>0.05); el área en la que se halló una mayor cantidad de microorganismos fue la bandeja (incluyendo botones de mando). Conclusión. Se determinó que tanto Lysol® como amonio cuaternario 5% son altamente eficaces para eliminar los microorganismos presentes en las superficies críticas de la unidad dental; además, el área más contaminada antes del uso de los tratamientos fue la bandeja, incluyendo los botones de mando.

Objective. Determine the antimicrobial efficacy of Lysol® and quaternary ammonium during the evaluation of three critical areas of the dental unit (control tray/buttons, dental chair back, and triple syringe handle). Methods. Through a cross-sectional comparative experimental study, a total of 8 dental chairs were analyzed: three were disinfected with Lysol®, three with quaternary ammonium, and two armchairs were selected as controls (positive and negative). All dental chairs were sampled twice a day: before use and at the end of use, for three days. Sampling was carried out at the Hemisferios University Clinics before and after the application of the disinfectant. The samples were transported in thioglycollate broth for analysis. 1:2 and 1:10 dilutions of each sample were plated on Plate Count Agar and incubated for 24 hours at 37°C. Subsequently, duplicate colony counts were performed, analyzing a total of 864 samples. Results. Lysol® and 5% quaternary ammonium showed equal antimicrobial effectiveness against the three areas analyzed (p>0.05). The area with the highest number of microorganisms was the tray (including control buttons). Conclusion. It was determined that both Lysol® and 5% quaternary ammonium are highly effective in eliminating microorganisms present on the critical surfaces of the dental unit. Furthermore, the tray, including the control buttons, was found to be the most contaminated area before treatment.

Fibrina rica en plaquetas como parte de la regeneración tisular en procedimientos quirúrgicos odontológicos / Platelet-rich fibrin as part of tissue regeneration in dental surgical procedures

Uno de los mejores biomateriales usados en odontología es la fibrina rica en plaquetas (PRF), es un concentrado plaquetario de segunda generación que se obtiene a partir de la centrifugación de sangre autóloga y no necesita aditivos. El presente documento busca determinar la eficacia del uso del PRF como parte de la regeneración de tejidos en procedimientos quirúrgicos odontológicos, tomando como base la literatura publicada en PubMed, Elsevier y Semantic Scholar entre 2018 y 2023, la búsqueda de artículos científicos fue ejecutada empleando las palabras clave platalet rich fibrin, regeneration, dentistry, blood buffy coat. La evidencia científica muestra que el PRF puede ser usado en su forma de membrana, gel, tapón, solo o combinado con otro biomaterial para conseguir propiedades biológicas exclusivas que promueven la regeneración y cicatrización mientras reduce los efectos adversos de los procedimientos quirúrgicos. Un ensayo clínico refirió la curación de alvéolos post exodoncia atraumática, y comprobó que la cicatrización con PRF muestra un índice de curación más alto en comparación con el grupo control. El sustento biológico de su eficacia radica en su capacidad para proliferar células que promueven la angiogénesis, osteogénesis y diferenciación celular, es decir, el reparo de tejidos lesionados. Todo esto nos permite llegar a la conclusión de que el PRF representa una alternativa viable y eficaz en procesos de regeneración de tejidos en procedimientos quirúrgicos odontológicos.

One of the best biomaterials used in dentistry is platelet-rich fibrin (PRF). It is a second-generation platelet concentrate obtained by centrifugation of autologous blood and requires no additives. The aim of this article is to determine the effectiveness of using PRF for tissue regeneration in dental surgery. The methodology used consists of a descriptive search of scientific articles that employ or study PRF as a biomaterial for tissue healing in the dental field and are available on PubMed, Elsevier, and Semantic Scholar. The literature shows that PRF can be used as a membrane, gel, cap form, alone or combined with other biomaterials to achieve unique biological properties that promote regeneration and healing while reducing the adverse effects of surgical procedures. For example, a clinical trial demonstrated healing of post-traumatic alveolar exodontia, proving that healing with PRF had a higher healing rate than in the control group. The biological basis of PRF's efficacy lies in its ability to proliferate cells that promote angiogenesis, osteogenesis, and cellular differentiation, and thus repair damaged tissue. All this leads us to conclude that PRF represents a viable and effective alternative in tissue regeneration processes in dental surgery procedures.

Radiographic interpretation of changes in the tooth and adjacent bone tissue using the tools of the Moodle virtual environment / Interpretação radiográfica de alterações no órgãodentário e tecido ósseo adjacente utilizando as ferramentas do ambiente virtual Moodle

Virtual learning environments (VLEs) have numerous possibilities for the use of their tools and can assist in the processesof teaching and learning aboutthe radiographic image interpretation. This study aimed to evaluate the use of a virtual learning environment as a support material for students in the discipline of Dental Radiology.This radiographic interpretation was conducted to contribute to the knowledge and training of the changes in the tooth andadjacent bone tissue,visualized in periapical and interproximal radiographs. The scores of the virtual test (via the Moodle platform) and the interpretation test (in the classroom) were used to compare Group Number 1 (students thatperformed the virtual test before the classroom test) and Group Number 2 (students thatperformed the virtual test after the classroom test). It was observed that,in general, the mean score of the interpretation test was higher than the virtual.Also,66% of the students used the platform as the main resourceto follow the discipline, due to the possibility of reviewing the contents andactivities. The virtual learning environment can be considered an important complementary sourcefor teaching radiographic interpretation. The Moodle platform acts as a remarkable tool, with the potential capacity to support the teaching and learning process. For this, mutual collaboration among students, University,and educational institution isnecessarily required for the constant use, maintenance,and updating of the virtual environment (AU).

Os ambientes virtuais de aprendizagem (AVA) possuem inúmeras possibilidades de utilização de suas ferramentas e podem auxiliar nos processos de ensino e aprendizagem sobre a interpretação de imagens radiográficas. Este estudo teve como objetivo avaliar a utilização de um ambiente virtual de aprendizagem como material de apoio para alunos da disciplina de Radiologia Odontológica. Essa interpretação radiográfica foi realizada para contribuir com o conhecimento e treinamento das alterações no órgão dentário e tecido ósseo adjacente, visualizadas em radiografias periapicais e interproximais. As notas da prova virtual (via plataforma Moodle) e da prova de interpretação (em sala de aula) foram utilizadas para comparar o Grupo Número 1 (alunos que realizaram a prova virtual antes da prova presencial) e o Grupo Número 2 (alunos que realizaram a prova virtual, após o teste em sala de aula). Observou-se que, em geral, a média da prova de interpretação foi superior à da prova virtual. Além disso, 66% dos alunos utilizaram a plataforma como principal recurso para acompanhar a disciplina, devido à possibilidade de revisão dos conteúdos e atividades. O ambiente virtual de aprendizagem pode ser considerado uma importante fonte complementar para o ensino da interpretação radiográfica. A plataforma Moodle atua como uma ferramenta notável, com potencial capacidade de apoiar o processo de ensino e aprendizagem. Para isso, é necessária a colaboração mútua entre alunos, Universidade e instituição de ensino para a constante utilização, manutenção e atualização do ambiente virtual (AU).

Radiographic changes of trabecular bone density after loading of implant-supported complete dentures: A 3-year prospective study.

BACKGROUND: Bone tissues may undergo remodeling under functional mechanical stimuli. PURPOSE: This prospective study on implant-supported fixed complete dentures (IFCDs) evaluated the radiographic trabecular bone changes in density by means of gray levels and texture analysis variables after up to 3-year loading. MATERIALS AND METHODS: The sample consisted of digital periapical radiographs of 63 distal implants of hybrid IFCDs installed in 30 patients (22 women, mean age of 62 ± 7.8 years). Digital periapical radiographs were taken after prosthesis installation, and 1 and 3 years after IFCD loading. Longitudinal images of each implant were superimposed, and the same regions of interest were selected for measurement of gray levels statistics (mean gray levels, SD, and coefficient of variation [CV]) and texture parameters (correlation, contrast, entropy, and angular second moment). Data were analyzed by mixed regression models. RESULTS: Mean gray levels increased for 1 year (P < .05), for 3 years (P < .01) and for maximum bite force (P < .01). The interaction between bruxism and time in 1 year was significant (P < .01) for a decrease in CV. No significant effect of texture analysis variables was found (P > .05). CONCLUSIONS: The results suggest an increase of radiographic bone density as measured by an increase in mean gray levels and a decrease in CV in IFCD distal implants up to 3 years of loading.

Relation between insertion torque and tactile, visual, and rescaled gray value measures of bone quality: a cross-sectional clinical study with short implants.

BACKGROUND: This study assessed the relationship between insertion torque and bone quality evaluated during surgery and in preoperative computed tomographic (CT) images analyzed either visually or by rescaled mean gray values (MGVs). The study also tested the correlation between the clinical and radiographic measures of bone quality. METHODS: The consecutive sample was composed of 45 short implants (4.1 × 6 mm) placed in the posterior region of 20 patients. Intra-surgical tactile bone quality, based on the classification of bone types by Lekholm and Zarb, and insertion torque were recorded during the implant placement. Visual bone quality and normalized MGV were assessed in standardized axial, coronal, and sagittal sections of preoperative CT images. Data were analyzed by ANOVA and Spearman correlation (alpha = 0.05). RESULTS: Insertion torque was associated with all assessment methods of bone quality (tactile, CT visual, MGV). A moderate correlation was found among all methods of bone quality, except for CT visual assessment and tactile evaluation. MGVs varied as a function of arch, dental region, insertion torque, and bone types. CONCLUSIONS: The results suggest that bone quality measures affect primary stability as recorded by insertion torque, and the assessment methods are consistently related.

Implant Inclination and Cantilever Length Are Not Associated with Bone Loss in Fixed Complete Dentures: A Prospective Study.

PURPOSE: To investigate whether the inclination of the most distal implant and the cantilever length influence marginal bone loss in implant-supported fixed complete dentures (ISFCDs). MATERIALS AND METHODS: A novel method using computed tomography images was developed to measure the mesiodistal implant inclination. The cantilever length was measured during ISFCD fabrication. Radiographs were obtained after ISFCD installation at 1 and 3 years after loading. RESULTS: A total of 30 subjects with 62 implants were included. Accumulated marginal bone loss was 0.35 ± 0.49 mm. No significant association was found between marginal bone loss and cantilever length or implant inclination. CONCLUSION: Implant inclination and cantilever length do not seem to affect marginal bone loss.

The influence of dental implants in periapical and panoramic radiographs and cone beam computed tomography images: a clinical study.

The aim of this study was to analyze the influence of dental implants on the radiographic density of the peri-implant region in tomographic and radiographic examinations. A sample of 21 dental implants from 10 patients with Brånemark-protocol prostheses was evaluated based on postoperative control images, including periapical radiography (paralleling technique), panoramic radiography, and cone beam computed tomography (CBCT). The density means of 6 defined areas near dental implants were calculated and compared considering their locations and the different imaging examinations. The CBCT examinations showed significantly different densities among the measured areas (P < 0.001), while there were no significant differences among the density means of the various areas in periapical radiographs (P = 0.430) and panoramic radiographs (P = 0.149). The highest mean densities were observed in areas closer to the implants in all the examinations: CBCT (127.88 and 120.71), panoramic (106.51 and 106.09), and periapical (120.32). The sagittal CBCT images were measured in 2 different sections, and in both sections those areas closer to implants showed mean densities that were significantly higher than means from more distant areas (P < 0.001). Means from distant areas on CBCT slice imaging were significantly lower than the densities of the same areas on periapical and panoramic examinations. The changes in mean radiographic density values in the peri-implant region confirmed the interference of dental implants in radiographic and tomographic images. CBCT images suffered the greatest interference from dental implants.

Validity of 2D lateral cephalometry in orthodontics: a systematic review.

Lateral cephalometric radiography is commonly used as a standard tool in orthodontic assessment and treatment planning. The aim of this study was to evaluate the available scientific literature and existing evidence for the validation of using lateral cephalometric imaging for orthodontic treatment planning. The secondary objective was to determine the accuracy and reliability of this technique. We did not attempt to evaluate the value of this radiographic technique for other purposes. A literature search was performed using specific keywords on electronic databases: Ovid MEDLINE, Scopus and Web of Science. Two reviewers selected relevant articles, corresponding to predetermined inclusion criteria. The electronic search was followed by a hand search of the reference lists of relevant papers. Two reviewers assessed the level of evidence of relevant publications as high, moderate or low. Based on this, the evidence grade for diagnostic efficacy was rated as strong, moderately strong, limited or insufficient. The initial search revealed 784 articles listed in MEDLINE (Ovid), 1,034 in Scopus and 264 articles in the Web of Science. Only 17 articles met the inclusion criteria and were selected for qualitative synthesis. Results showed seven studies on the role of cephalometry in orthodontic treatment planning, eight concerning cephalometric measurements and landmark identification and two on cephalometric analysis. It is surprising that, notwithstanding the 968 articles published in peer-reviewed journals, scientific evidence on the usefulness of this radiographic technique in orthodontics is still lacking, with contradictory results. More rigorous research on a larger study population should be performed to achieve full evidence on this topic.

Radiopacities of glass ionomer cements measured with direct digital radiographic system.

PURPOSE: The purpose of this study was to determine and compare the radiopacities of 5 glass ionomer cements (GICs) of different thickness using a digital radiographic system-storage phosphor plate. METHODS: The GICs tested were Vitremer, Vitrofil LC, Magic Glass, Vitromolar, and Maxxion, distributed into the orifices of 16 acrylic plates made to a thickness of 2 mm, 3 mm, 5 mm, and 6 mm. Each plate was radiographed 3 times, and the images obtained were processed by computer. The images were read 3 times using the VixWin 2000 program, totaling 720 readings of radiographic density. One-way analysis of variance was applied for statistical analysis with identification of differ- ences using Scheffe's multiple comparisons test (α=5%). RESULTS: All the GICs varied in radiopacity according to thickness. Maxxion showedthe lowest value of radiopacity, whereas Magic Glass displayed the highest level of radiopacity at all thicknesses studied. However, Vitremer and Vitrofil LC showed similar results. CONCLUSION: It is important to know GIC radiopacities to help differentiate them from tooth structure and carious lesions as well as to use them correctly.

Accuracy of linear measurements before and after digitizing periapical and panoramic radiography images.

The aim of this study was to evaluate the accuracy of linear measurements made on conventional and digitized periapical and panoramic radiographic images of dry human hemi-mandibles. Images from the posterior region of 22 dry human hemi-mandibles were obtained by conventional panoramic and periapical radiography technique. Using a digital caliper, 3 vertical measurements were marked directly on the dry hemi-mandibles (reference measurements) as well as on the tracing from the conventional radiographic images of the specimens made onto acetate paper sheet: Distance 1: between the upper limit of the alveolar ridge and the lower limit at the mandible base; Distance 2: between the upper limit of the alveolar ridge and the upper limit of the mandibular canal; Distance 3: between the lower limit of the mandibular canal and the lower limit of the mandible base. Next, the radiographs were digitized and the three measurements were made on the digital images using UTHSCSA Image Tool software. Data were analyzed statistically by one-way ANOVA (α=0.05). There was no statistically significant differences (p>0.05) between periapical and panoramic radiographs or between the measurements recorded using the digital caliper and UTHSCSA software compared with dry mandible specimens for Distances 1 (p=0.783), 2 (p=0.986) and 3 (p=0.129). In conclusion, the radiographic techniques evaluated in this study are reliable for vertical bone measurements on selected areas and the UTHSCA Image Tool software is an appropriate measurement method.

Response to intracanal medication in immature teeth with pulp necrosis: an experimental model in rat molars.

INTRODUCTION: The present study aimed at developing an experimental model in rat molars for evaluating treatment strategies in necrotic immature teeth. METHODS: To define the periods to be adopted in the experimental procedures and to confirm induction of periapical lesions and interruption of root embryogenesis, the left lower first molars of 4-weeks-old Wistar rats underwent pulpectomy and were left open to the oral environment. Comparisons with the right lower first molars (vital teeth) were performed in animals with ages of 7, 10, 13, and 16 weeks. In another group of animals the teeth were left open for 3 weeks, and then interventions for disinfection including the use of an antibiotic paste were carried out. Root formation was then assessed after 3 and 6 weeks on the basis of radiographic and histologic evaluation. RESULTS: Vital teeth showed increase of root length and hard tissue thickness throughout the experimental periods. On the other hand, induction of necrosis arrested root formation. Teeth subjected to disinfection with sodium hypochlorite associated with the triple antibiotic paste showed significant reduction of periapical lesions, gain in root length, and increased wall thickness compared with the control (P < .05). CONCLUSIONS: The root canal disinfection protocol used was able to reduce periapical lesion size and improve root development. The experimental model presented should contribute to studies that aim at improving therapeutic strategies for necrotic immature teeth by using a rat model.

Accuracy of linear measurements before and after digitizing periapical and panoramic radiography images

The aim of this study was to evaluate the accuracy of linear measurements made on conventional and digitized periapical and panoramic radiographic images of dry human hemi-mandibles. Images from the posterior region of 22 dry human hemi-mandibles were obtained by conventional panoramic and periapical radiography technique. Using a digital caliper, 3 vertical measurements were marked directly on the dry hemi-mandibles (reference measurements) as well as on the tracing from the conventional radiographic images of the specimens made onto acetate paper sheet: Distance 1: between the upper limit of the alveolar ridge and the lower limit at the mandible base; Distance 2: between the upper limit of the alveolar ridge and the upper limit of the mandibular canal; Distance 3: between the lower limit of the mandibular canal and the lower limit of the mandible base. Next, the radiographs were digitized and the three measurements were made on the digital images using UTHSCSA Image Tool software. Data were analyzed statistically by one-way ANOVA (α=0.05). There was no statistically significant differences (p>0.05) between periapical and panoramic radiographs or between the measurements recorded using the digital caliper and UTHSCSA software compared with dry mandible specimens for Distances 1 (p=0.783), 2 (p=0.986) and 3 (p=0.129). In conclusion, the radiographic techniques evaluated in this study are reliable for vertical bone measurements on selected areas and the UTHSCA Image Tool software is an appropriate measurement method.

O objetivo deste estudo foi avaliar a acurácia de medidas lineares realizadas em radiografias panorâmicas e periapicais convencionais e digitalizadas de hemimandíbulas humanas secas. Imagens da região posterior de 22 hemimandíbulas humanas secas foram obtidas pelas técnicas panorâmica e periapical convencionais. Com o paquímetro eletrônico digital, foram realizadas três medições verticais diretamente sobre as hemimandíbulas (medidas referenciais), bem como sobre o decalque das imagens convencionais, em papel de acetato: Distância 1: Distância entre o limite superior do rebordo alveolar e o limite inferior da base da mandíbula; Distância 2: Distância entre o limite superior do rebordo alveolar e o limite superior do canal mandibular e Distância 3: Distância entre o limite inferior do canal mandibular e o limite inferior da base da mandíbula. Posteriormente, as radiografias foram digitalizadas e as três medidas foram realizadas nas imagens digitais utilizando o programa UTHSCSA Image Tool. Os dados foram analisados estatisticamente pelo teste ANOVA a um critério (α=0,05). Não houve diferenças estatisticamente significantes (p>0,05) entre as radiografias panorâmicas e periapicais, assim como para as medidas obtidas com o paquímetro e pelo programa UTHSCSA Image Tool, quando comparados aos espécimes mandibulares, avaliando as distâncias 1 (p=0,783), 2 (p=0,986) e 3 (p=0,129). Em conclusão, as técnicas radiográficas avaliadas neste estudo mostraram-se confiáveis para mensurações ósseas verticais na área selecionada e o programa de digitalização de imagens UTHSCSA Image Tool é um método adequado de aferição.

Projection of the oblique line in periapical radiographs of mandibular molars / Projeção da linha oblíqua na região de molares inferiores em radiografias periapicais

Purpose: To identify and quantify the frequency of the projection of the oblique line over the alveolar crests of the mandibular molars in periapical radiographs. Methods: Five hundred periapical radiographs of the mandibular molar region were selected and evaluated for the presence or absence of the oblique line. When present, its interference on the image of the alveolar crest of the mandibular molars was analyzed. The data obtained was expressed as a percentage of the overlap of the oblique line to the alveolar crests of the mandibular molars. Results: The oblique line was observed in 363 out of the 500 periapical radiographs (72.6%). Out of the 363, 308 (84.8%) showed an overlap of the oblique line over the alveolar crests. However, 55 radiographs (15.1%) did not show such interference. Of the radiographs showing an overlap (308), the incidence of an overlap was 64.6% at a single site (199 radiographs), 33.4% at two sites (103 radiographs), and 1.9% (6 radiographs) at three sites. Conclusion: The overlap of the oblique line over the image of the alveolar crests in the mandibular molar region was observed in a significant portion of the total sample.

Objetivo: Identificar e quantificar a frequência da projeção da linha oblíqua sobre as cristas alveolares dos molares inferiores em radiografias periapicais. Metodologia: Foram selecionadas 500 radiografias periapicais da região de molares inferiores e avaliada a presença ou a ausência da linha oblíqua. Quando presente, foi analisada a interferência desta estrutura sobre a imagem das cristas alveolares dos molares inferiores. Os dados obtidos, considerando a frequência da sobreposição da linha oblíqua sobre as cristas alveolares dos molares inferiores foram expressos em percentagens. Resultados: Nas 500 radiografias periapicais avaliadas, a linha oblíqua foi observada em 363 radiografias (72,6%). Nestas, em 308 (84,8%), houve sobreposição da linha oblíqua sobre as cristas alveolares. Entretanto, em 55 radiografias (15,1%) não foi encontrada interferência. Nas radiografias em que houve a sobreposição da linha oblíqua sobre as cristas alveolares (308), a incidência de sobreposição em apenas um local foi de 64,6% (199 radiografias); em dois locais foi de 33,4% (103 radiografias) e em três locais foi de 1,9% (6 radiografias). Conclusão: A sobreposição da linha oblíqua sobre a imagem das cristas alveolares na região de molares inferiores representou uma fração significativa do total da amostra.

Effects of radio-opacifier addition in dental impression material.

OBJECTIVE: The aim of this in vitro study was to determine the effects of barium sulfate addition in two dental impression materials previously proved as radiolucent. MATERIALS AND METHODS: An irreversible hydrocolloid (IH) and polyether (PE) were tested for optical density, linear dimension stability and detail reproduction. STATISTICAL ANALYSIS USED: The optical density data were submitted to Kolmogorov-Smirnov normality test and compared with two-way ANOVA and Tukey (alpha=0.05). RESULTS: The results of optical density (pixel) were: IH control 45.24 f (+/-7.6), PE control 54.93 e (+/-4.45), PE 5Wt% 60.43 d (+/-6.27), IH 1Wt% 61.54 cd (+/-5.3), PE 1Wt% 66.9 bc (+/-5.05), IH 5Wt% 67.17 b (+/-6.01), PE 10Wt% 84.55 a (+/-5.14), IH 10Wt% 85.33 a (+/-5.53). On detail reproduction, polyether control was able to copy the 6 microm line. Adding 1 or 5Wt% of barium sulfate have not change this characteristic. For the irreversible hydrocolloid, the control group was able to copy a line with 14 microm, however, adding 1Wt% barium sulfate, the capability decreased to 22 microm. Adding barium sulfate in the polyether promoted an increase in between the copied lines, for the control, the average distance was 931.6 microm, 936 microm to 1Wt% and 954.5 microm to 5 Wt%. For the IH, the control presented 975 microm in comparison to 987.25 microm for 1 Wt% samples. CONCLUSION: The addition of barium sulfate was capable of increasing significantly the optical density of tested material, have changed the linear dimension stability, however, have not interfered in detail reproduction only for PE.

Comparación entre radiografías convencionales y digitales en la medición de canales radiculares / Comparison between digital and conventional X-ray measurement in root canals

El objetivo de este estudio fue comparar radiografías convencionales y digitales en la medición de canales radiculares. Fueron utilizados 50 dientes humanos monorradiculares. Las raíces dentarias fueron posicionadas sobre la película o placa de fósforo, en sentido de su mayor eje, y el fajo de rayos X incidió perpendicular a ambos, con una distancia focal de 30 cm y tiempo de exposición de 0,08s. Las radiografías convencionales fueron obtenidas utilizando película periapical nº 2 (InSight, Kodak) y medidas con regla milimetrada y paquímetro digital, y las radiografías digitales obtenidas con los sistemas DenOptix y Digora, cuyas imágenes fueron medidas utilizando los recursos de sus programas. Las medidas reales fueron obtenidas utilizando limas tipo K (Dentisply-Maillefer) nº20, que fueron medidas utilizando también regla y paquímetro. La largura del canal fue medida a partir de la base cervical hasta la salida del foramen visualizado en la imagen, o hasta el ápice anatómico verificado por medio de estereomicroscopia. Todas las mediciones fueron realizadas dos veces por dos observadores (ICC= -0,60 a -0,99). El sistema Denoptix mostró el menor promedio de variación, en milímetros, cuando comparado al patrón-oro (0,12 mm e 0,22 mm). El método convencional medido con regla mostró el mayor promedio de variación (0,50 mm). Los valores obtenidos con el sistema Digora fueron próximos a los obtenidos con el sistema convencional (t-Student e Friedman; p< 0,05). Los tres métodos radiográficos mostraron diferencias estadísticamente significativas cuando comparados a los valores reales de los canales radiculares

The objective of this study was to compare conventional and digital radiographs to measure root canals. Fifty permanent single-canal teeth were employed. The roots were placed on the film or on the storage phosphor plate on their longest axes. And they were perpendicularly exposed to the x-ray beam in a distance of 30 cm with the exposure time of 0.08 s. The conventional radiographs were obtained using periapical film #2 (InSight, Kodak). They were measured with a millimeter ruler and with a digital calipter. The digital radiographs were obtained with DenOptix and Digora systems. Their images were measured with their programs tools. The real measures were obtained using K-files #20 (Dentisply-Maillefer). They were also measured using the ruler and the digital calipter. The canal length was measured from the cervical part to the apical foramina observed in the radiographs or to the anatomic apex by stereomicroscopy. Two observers made the measurements of the root canals twice (ICC= - 0.60 -0.99). DenOptix system presented the least average range in millimeters when compared to the gold standard (0.12 mm and 0.22mm). The conventional method (film) presented the largest average range (0.55mm) when measured with the ruler. The values obtained with Digora system were similar to the values obtained with the conventional method (t-Student and Friedman; p<0.05). The three radiographic methods showed differences statistically significant from the real measurements of the real canals

Range of exposure time and image quality in conventional and digital radiographs: an in vitro study

The purpose of this study was to determine the range of exposure time to obtain acceptable bitewing radiographic images using conventional (InSight, Kodak) and digital (DenOptixTM, Gendex) systems. Thirty sound molars were radiographed by bitewing technique at exposure times ranging from 0.06s to 2.50s. Five dental radiologists evaluated the resulting 340 radiographs, classifying them as(1) unacceptable, (2) acceptable and (3) of good quality. Frequencies were analyzed by Kruskal-Wallis and Wilcoxon tests, and inter-examiner agreement was determined by Cohen’s kappa statistics. Radiographs of good diagnostic quality in conventional system were obtained with exposure times ranging from 0.10s to 1.00s while in digital system the time ranged from 0.06s to 1.60s (P<0.05). It was also observed that 75.3 per cent of the digital images and 47.1 per cent of the conventional images were considered of good quality...

O objetivo deste estudo foi determinar o intervalo de tempo de exposição aceitável para obter imagens radiográficas interproximais utilizando sistemas convencionais (Insight, Kodak) e digital (DenOptixTM, Gendex). Trinta molares foram radiografados pela técnica interproximal em tempos de exposição variando de 0.06s de 2.50s. Cinco radiologistas odontólogos avaliaram 340 radiografias classificando-as como (1) inaceitáveis, (2) aceitável e (3) de boa qualidade. As freqüências foram analisadas pelo teste de Kruskal-Wallis e Wilcoxon, e concordância entre os examinadores foi determinada pela estatística kappa de Cohen. As radiografias de boa qualidade diagnóstica em sistema convencional foram obtidos com tempos de exposição variando de 0,10s a 1.00s, enquanto no sistema digital, o tempo variou de 0.06s a 1.60s para (P <0,05). Também foi observado que 75,3 por cento das imagens digitais e 47,1 por cento das imagens convencionais foram considerados de boa qualidade...

Radiopacity of impression materials using an indirect digital system / Radiopacidade de materiais de moldagem usando um sistema digital indireto

Purpose: This in vitro study evaluated the radiopacity of impression materials using an indirect digital system. Methods: Samples of four polyvinyl siloxanes, one polyether, one polysulfide, and one irreversible hydrocolloid were fabricated with 1.0, 1.5, and 3.5mm-thickness. Three samples of different thickness were placed on the Digora optical plate and exposed. The optical density (pixels) was recorded in three areas resulting in a total of 360 measurements. Data were analyzed by 2-way ANOVA and Tukey tests (α=0.05). Results: Significant differences were observed among all materials and thicknesses tested (P<0.001). Irreversible hydrocolloid and polyether showed the lowest optical density. Polysulfide showed the highest optical density under all evaluated conditions. Conclusion: There was a significant difference in optical density for all impression materials tested. Composition changes are suggested to allow radiographic detection and improve safety during clinical use of impression materials.

Objetivo: Este estudo in vitro comparou a radiopacidade de materiais de moldagem usando um método radiográfico digital indireto. Metodologia: Amostras de quatro polivinil-siloxanos, um poliéter, um polissulfeto e um hidrocolóide irreversível foram confeccionadas com alturas de 1, 1,5 e 3,5mm. Três amostras das diferentes espessuras foram dispostas sobre uma placa óptica Digora e exposta. A densidade óptica (pixels) foi registrada em três diferentes áreas de cada amostra. Os dados foram analisados pelo teste de análise de variância de dois fatores e teste de Tukey (α=0,05). Resultados: Diferenças significantes foram observadas entre todos os materiais e espessuras testadas (P<0,001). O hidrocolóide irreversível e o poliéter apresentaram a menor densidade óptica. O polissulfeto apresentou a maior densidade óptica em todas as condições avaliadas. Conclusão: Há diferença significativa na densidade óptica dos materiais de moldagem avaliados. Alterações na composição são necessárias para facilitar a detecção destes materiais a fim de aumentar a segurança no uso clínico.

Considerações sobre as modalidades radioterapêuticas empregadas para o tratamento de neoplasias na região de cabeça e pescoço / Considerations of the radiotherapy modalities used in the managementof head and neck neoplasms

O tratamento das neoplasias localizadas na região de cabeça e pescoço pode ser realizado por meio de cirurgia, radioterapia, quimioterapia, ou da associação dessas modalidades terapêuticas. A radioterapia acarreta danos aos tecidos normais, os quais podem resultar em complicações que afetam a qualidade de vida dos pacientes. Os autores deste estudo fazem uma revisão sobre as modalidades radioterapêuticas e os esquemas terapêuticos empregados no tratamento das neoplasias na região de cabeça e pescoço, enfatizando a necessidade de o cirurgião-dentista conhecer as implicações clínicas decorrentes da utilização dos distintos protocolos, para que possa realizar o melhor atendimento odontológico dos pacientes irradiados.

Detection of proximal caries in conventional and digital radiographs: an in vitro study.

OBJECTIVES: To compare digital images to conventional film radiography in the diagnosis of proximal caries. METHODS: Fifty-one molars and 24 premolars were studied and divided in groups of three teeth. They were fixed in silicone and radiographed using InSight film (Kodak) and the digital systems Digora (Soredex), DenOptix (Gendex) and CygnusRay MPS (Progeny). Twenty-five radiographs were obtained in each modality and four proximal surfaces were analyzed in each radiograph. Radiographs were interpreted individually by one observer at three different sessions for each imaging modality. Caries lesions were classified according to their depth: (0) absent; (1) restricted to enamel; (2) reaching the dentino-enamel junction; and (3) reaching the dentin. The teeth were sectioned and ground in order to obtain the gold standard and were examined histologically by stereomicroscopy. RESULTS: The Kendall test was employed and showed a good intra-observer agreement among the three evaluations implemented. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were all calculated, and there were no significant differences observed among the four imaging modalities studied (ANOVA, p< or =0.05). Besides, the ROC curve was determined for each modality and no statistically significant differences were observed when comparing the areas under the ROC curve at the 5% level of significance. CONCLUSIONS: The results demonstrate that the diagnostic accuracy of digital images is similar to that of conventional film radiography in the detection of proximal caries.