Resumo O objetivo deste estudo foi avaliar o desempenho dos cirurgiões na determinação da quantidade de material de enxerto necessária para a elevação do assoalho do seio maxilar em uma análise pré-operatória, utilizando imagens de tomografia computadorizada de feixe cônico. Foi selecionada uma amostra de conveniência de 10 exames retrospectivos CBCT (i-CAT®). Os exames foram da área da maxila posterior que possuíam ausência de pelo menos um dente e com osso alveolar residual de altura igual ou inferior a 5 mm. Os templates (n=20) continham imagens de secções transversais representativas numa vista multiplanar. Dez experientes cirurgiões voluntariamente participaram como avaliadores dos templates para o planejamento cirúrgico de enxerto para um implante de 10 mm de comprimento. Os avaliadores escolheram a melhor quantidade de material de enxerto usando os escores: 0) quando o enxerto era desnecessário, 1) para 0,25 g de enxerto, 2) para 0,50 g, 3) para 1,00 g, e 4) para 1,50 g ou mais. A confiabilidade do padrão de resposta foi analisada utilizando a a de Cronbach. Os testes de Wilcoxon e Mann-Whitney foram utilizados para comparar os escores. A análise de regressão foi realizada para avaliar se o volume dos seios (mm3) influenciou a escolha dos escores. Na análise de confiabilidade, todos os valores foram baixos e a distribuição dos escores foi independente do volume dos seios maxilares (p>0,05), o que não influenciou a escolha da quantidade de material de enxerto. Os cirurgiões apresentaram falta de confiabilidade ao determinar a melhor quantidade de material de enxerto para o aumento do assoalho do seio maxilar utilizando somente as imagens de TCFC. Assim, os cirurgiões necessitam de ferramentas de diagnóstico auxiliares para mensuração de volume associada à TCFC para um melhor desempenho.

Abstract This study aimed to assess the performance of surgeons in determining the amount of graft material required for maxillary sinus floor augmentation in a preoperative analysis using cone-beam computed tomography images. A convenience sample of 10 retrospective CBCT exams (i-CAT®) was selected. Scans of the posterior maxilla area with an absence of at least one tooth and residual alveolar bone with an up to 5 mm height were used. Templates (n=20) contained images of representative cross-sections in multiplanar view. Ten expert surgeons voluntarily participated as appraisers of the templates for grafting surgical planning of a 10 mm long implant. Appraisers could choose a better amount of graft material using scores: 0) when considered grafting unnecessary, 1) for 0.25 g in graft material, 2) for 0.50 g, 3) for 1.00 g and 4) for 1.50 g or more. Reliability of the response pattern was analyzed using Cronbach’s a. Wilcoxon and Mann-Whitney tests were performed to compare scores. Regression analysis was performed to evaluate whether the volume of sinuses (mm3) influenced the choose of scores. In the reliability analysis, all values were low and the score distribution was independent of the volume of the maxillary sinuses (p>0.05), which did not influence choosing the amount of graft material. Surgeons were unreliable to determine the best amount of graft material for the maxillary sinus floor augmentation using only CBCT images. Surgeons require auxiliary diagnostic tools to measure the volume associated to CBCT exams in order to perform better.

Three-dimensional imaging modalities have been reported to be more accurate than panoramic radiographs (PR) for the assessment of bone components of the temporomandibular joint (TMJ). No exact prior information is available that demonstrates which specific limitations occur in terms of TMJ diagnosis when using PR for this purpose. This study aimed to assess the clinical validity of digital panoramic radiography (DPR) when diagnosing morphological disorders of the TMJ using cone-beam computed tomography (CBCT) images as the gold standard. A sample composed of TMJ images (N = 848), including 212 DPR and 212 CBCT images obtained from the same patient, was used to assess any morphological changes in the TMJ. Four appraisers diagnosed all of the DPR images, whereas the CBCT images were used to establish the gold standard. The reliability of each appraiser’s response pattern was analyzed using the Kappa test (κ), and diagnostic tests were performed to assess each appraiser’s performance using a significance level setting of 5% (α = 0.05). Reliability of each appraiser’s response pattern compared to the gold standard ranged from a slight-to-moderate agreement (0.18 ≤ κ ≤ 0.45); and among the different appraisers, the response pattern showed a fair agreement (0.22 ≤ κ ≤ 0.39). Diagnostic tests showed a wide range among the different possible morphological changes diagnosed. DPR does not have validity when diagnosing morphological changes in the TMJ; it underestimates the radiological findings with higher prevalence, and thus, it cannot be used effectively as a diagnostic tool for bone components within this region.

The aim of this study was to use cone-beam computed tomography (CBCT) images to evaluate the prevalence and configurations of C-shaped canals in permanent mandibular second molars among members of a Brazilian subpopulation. CBCT exams of 214 patients (406 teeth) were evaluated for: presence of C-shaped root canals, number of canals and direction of the root grooves (buccal or lingual). Of the 214 CBCT images examined, 192 showed intact bilateral molars, which were used to analyze the distribution of unilateral and bilateral occurrences of C-shaped canals. The prevalence of these canals was correlated with gender and age, and the number of canals was correlated with the direction of the root grooves using the chi-squared test (α = 0.05). The prevalence of C-shaped canals was 15.3%. This prevalence did not differ with gender or age. Most of the C-shaped molars had three (43.5%) or two (37.1%) canals; 69.4% of the C-shaped canals were grooved in the buccal direction; 68.3% of the C-shaped cases were unilateral. In conclusion, there was a significant prevalence of C-shaped canals in the mandibular second molars of the population studied; the C-shaped canal system varied in configuration, with a higher prevalence of three and two canals and unilateral occurrence; CBCT is a useful tool for endodontic diagnosis and treatment.

O objetivo deste estudo foi avaliar a aplicabilidade da inversão da escala de cinza na realização de mensurações endodônticas lineares digitais. Quarenta dentes unirradiculares humanos extraídos foram radiografados com limas K tamanho 15 posicionadas no canal radicular em diferentes comprimentos, usando o sistema digital CDR Wireless®. Todas as imagens foram tratadas com Positive, uma ferramenta digital que inverte os valores da escala de cinza. Oito radiologistas mediram a distância entre o limite inferior do stop de borracha e a ponta da lima endodôntica nas imagens originais e positivas. Após quinze dias, eles repetiram esse procedimento em 50% da amostra. A concordância intra- e interobservador foi analisada pelo teste de correlação intraclasse e a comparação entre os dois grupos de imagem e os valores reais, pelo teste t-Student (α=0,05). A análise intra- e interobservador apresentou elevada reprodutibilidade (r>0,95) das imagens original e Positive. Não foi encontrada diferença (p>0,05) entre as medidas realizadas nas imagens original e positiva, mas ambas diferiram dos valores reais (p<0,05). A inversão da escala de cinza tem baixa aplicabilidade na realização de mensuração endodôntica, considerando que as medidas não se apresentaram mais acuradas

The aim of this study was to assess the applicability of gray scale inversion in performing digital linear endodontic measurements. Standardized digital images were taken of 40 extracted human permanent single-rooted teeth with K-files size 15 placed at different lengths in the root canal, using the CDR Wireless® digital system. All images were treated with Positive, a digital tool that inverts the grayscale value. Eight radiologists measured the distance between the lower limit of the rubber stop and the tip of the file on both original and positive images. After 15 days, they repeated this procedure in 50% of the image samples. The intra- and inter-examiner agreement was analyzed by intraclass correlation test, and the comparison between the two image groups and the actual lengths by the Student's t-test (α=0.05). Intra- and inter-examiner evaluation showed high reproducibility (r>0.95) of both original and positive images. No statistically significant differences (p>0.05) were found between measurements performed on original and positive images, but both differed significantly from the actual lengths (p<0.05). Gray scale inversion has low applicability in measuring endodontic files, since it did not improve the accuracy of measurements.

O objetivo deste estudo foi avaliar a precisão no diagnóstico de lesões iguais-à-cárie secundárias simuladas em restaurações estéticas de materiais diferentes, mudando o ângulo vertical de incidência (AVI) do feixe de raios-x. Vinte dentes humanos foram submetidos a preparo cavitário inlay MOD. No grupo experimental (n=10), no soalho da caixa de proximal, foi confeccionada uma cavidade esférica para simular lesões iguais-a-cárie. Todos os dentes foram restaurados com 3 resinas compostas (Charisma, Filtek-Z250, TPH-Spectrum), em três tempos diferentes. Duas imagens radiográficas foram adquiridas com 0 e 10 graus de AVI o feixe de raios-x. Dez observadores avaliaram as imagens usando uma escala de confiança de 5-pontos. A reprodutibilidade intra- e inter- observador foi analisada com o coeficiente de correlação interclasse e a precisão do diagnóstico foi avaliada usando a área sob a curva ROC (Az), o teste de Friedman e de Wilcoxon (α=0,05). Os mais altos valores de precisão (p>0,05) foram observados com o AVI em 10º (Filtek-Z250 Az=0,66>TPH-Spectrum Az=0,56) comparado com 0º (Charisma Az=0,55>TPH-Spectrum Az=0,37), porém, sem diferenças estatisticamente significantes (p>0,05). A detecção de lesões iguais-à-cárie secundárias simulada em restaurações estéticas de diferentes materiais não foi influenciada pela mudança de AVI do feixe de raios-x.

The aim of this study was to evaluate the accuracy on the diagnosis of secondary caries-like lesions simulated on esthetic restorations of different materials, changing the incidence vertical angle (IVA) of the x-ray beam. Twenty human teeth received MOD inlay preparations. In the experimental group (n=10), a round cavity was made in the floor of the proximal box to simulate the caries-like lesion. All teeth were restored with 3 composite resins (Charisma, Filtek-Z250 and TPH-Spectrum) at 3 moments. Two radiographic images were acquired with 0º and 10º IVA. Ten observers evaluated the images using a 5-point confidence scale. Intra- and interobserver reliability was analyzed with the Interclass Correlation Coefficient and the diagnostic accuracy was evaluated using the area under the ROC curve (Az), Friedman test and Wilcoxon test (α=0.05). Higher accuracy values were obtained with 10º IVA (Az=0.66, Filtek-Z250>Az=0.56, TPH-Spectrum) compared to 0º (Az=0.55, Charisma>Az=0.37, TPH-Spectrum), though without statistically significant difference (p>0.05). The detection of secondary caries-like lesions simulated on esthetic restorations of different materials suffered no negative influence by changing the IVA of the x-ray beam.

O objetivo na presente pesquisa foi determinar o tamanho, forma e posição da camada de imagem por meio da avaliação da formação da imagem radiográfica em diferentes posições anatômicas. Foi construído um phantom constituído por uma placa acrílica de 14 cm² e 0,3 cm de espessura, com sua superfície contendo perfurações a cada 0,5 cm dispostas em linhas e colunas. O phantom foi posicionado no local do apoio de mento do aparelho panorâmico, com sua superfície paralela ao plano horizontal. Esferas metálicas de 0,315 cm foram inseridas nas perfurações, e executadas radiografias panorâmicas. Cada coluna de cada quadrante foi individualmente preenchida pelas esferas para a execução das radiografias, em três planos horizontais diferentes: alturas orbital, oclusal e mentual. As imagens das esferas foram medidas com o uso de um paquímetro digital e a camada de imagem localizada. Os dados foram analisados estatisticamente utilizando-se o teste T Student, ANOVA e teste de Tukey (?=0,05). Quando o tamanho das esferas nos eixos horizontal e vertical foi comparado, diferenças estatisticamente significativas (p<0,05) foram observadas em todas as áreas da camada de imagem, porções e alturas do plano horizontal avaliado. Na porção central da camada de imagem diferenças no tamanho das esferas foram observadas somente no eixo horizontal (p<0,05), enquanto que no eixo vertical nenhuma diferença foi observada (p>0,05). A metodologia utilizada determinou com precisão o tamanho, forma e posição da camada de imagem, e diferenças de ampliação foram observadas tanto no eixo horizontal quanto vertical.

The aim of this study was to determine size, shape and position of the image layer by evaluation of the radiographic image formation in different anatomic positions. A customized phantom was made of a rectangular acrylic plate measuring 14 cm² and 0.3 cm thick, with holes spaced 0.5 cm away and arranged in rows and columns. Each column was separately filled with 0.315 cm diameter metal spheres to acquire panoramic radiographs using the Orthopantomograph OP 100 unit. The customized phantom was placed on the mental support of the device, with its top surface kept parallel to the horizontal plane, and was radiographed at three different heights from the horizontal plane, i.e., the orbital, occlusal and mandibular symphysis levels. The images of the spheres were measured using a digital caliper to locate the image layer. The recorded data were analyzed statistically by the Student'-t test, ANOVA and Tukey' test (?=0.05). When the image size of spheres in horizontal and vertical axes were compared, statistically significant differences (p<0.05) were observed in all areas, portions of the image layer and heights of horizontal plane evaluated. In the middle portion of the image layer, differences in the image size of spheres were observed only along the horizontal axis (p<0.05), whereas no differences were observed along the vertical axis (p>0.05). The methodology used in this determined the precise size, shape and position of the image layer and differences in magnification were observed in both the horizontal and vertical axes.

The aim of this study was to investigate the influence of therapeutic dose X rays on the microhardness (MH) and degree of conversion (DC) of two different esthetic restorative dental materials. The materials were photo-activated with a LED light-curing unit using three cure-times: 5, 20 and 40 seconds. The photo-activation was carried out in two distinct periods: before and after irradiation with doses of 5, 35 and 70 Gy, from a 6 MV X rays beam. In accordance with the methodology used, it was conclude that a therapeutic dose does not have a detrimental effect on the photoinitiator molecules, because the photo-activation occurred after they were irradiated. When the irradiation was applied before photo-activation, the materials showed MH improvement, but when photo-activation was performed after irradiation, there was less improvement. However, there was no correlation between MH and DC. Thus, a therapeutic dose applied to cured material can promote linking and breaking of chain bonds in a non-linear way.

This study aimed at investigating the effect of the partial erasing of DenOptix® system storage phosphor plates on the image quality of digital radiographs. Standardized digital radiographs were acquired of a phantom mandible, using size 2 intraoral DenOptix® storage phosphor plates (n = 10). Subsequently, the active areas of the plates were placed in a viewing box with a constant light intensity of 1,700 lux for 130 seconds to achieve complete erasing (control plate), as well as for 0, 5, 10, 15, 20, 25, 34, 66, and 98 seconds, to compose the experimental group of partially erased plates. The same exposure settings were repeated using the control and experimental plates, which were scanned at a resolution of 300 dpi. Five radiologists independently examined the pairs of digital radiographs obtained with the control and partially erased plates, in random order, and indicated the best image for oral diagnosis. Cochran-Mantel-Haenszel’s chi-square test, at a significance level of 5%, was used to compare the percentages of superior quality images in each combination of control and partially erased plates, subjectively assessed. No significant differences were found between radiographic images acquired with control and partially erased plates, except for the combination of 0 second (30%) versus 130 seconds (70%), p = 0.0047. It can be concluded that, under adequate light intensity conditions, erasing intraoral DenOptix® storage phosphor plates may require time intervals of as little as 5 seconds.

O objetivo deste estudo foi avaliar o efeito da irradiação por baixa dose de elétrons sobre características morfológicas da reparação tecidual na pele de rato. Foram realizadas feridas cirúrgicas com um gabarito de 2,3 x 1,4 cm em 84 ratos machos, divididos em 4 grupos: IG1, irradiado imediatamente; IG2, irradiado 3 dias após a produção da ferida; CG1 e CG2, grupos controles. Os ratos dos grupos IG1 e IG2 tiveram suas feridas expostas a 1 Gy de radiação por elétrons com 6 MeV, imediatamente após a cirurgia e ao terceiro dia pós-operatório, respectivamente. Procedeu-se às avaliações qualitativas e histofotométrica das estruturas de reparação tecidual. Os dados foram submetidos a ANOVA e teste Tukey (a = 0,05) e análise de regressão. O processo de reparação apresentou-se atrasado desde o primeiro tempo de sacrifício em ambos os grupos irradiados, mas para IG1, a reparação tecidual foi similar a CG1. Por outro lado, para IG2, o retardo foi mais pronunciado. Com base nas avaliações histológicas, é possível concluir que uma baixa dose de radiação por elétrons retardou a reparação na pele de rato. O atraso foi maior na pele irradiada 3 dias após o início da reparação tecidual. No entanto, esta irradiação por elétrons de baixa energia não impediu a cicatrização.

The aim of this study was to assess the effect of low-dose electron irradiation on morphological features of the wound healing process in rat skin. Surgical wounds were inflicted with a 2.3 x 1.4 cm template on 84 male rats that were assigned to 4 groups: IG1, immediately irradiated; IG2, irradiated 3 days after inflicting the wound; CG1 and CG2, control groups. Rats in IG1 and IG2 groups had their wounds exposed to 1 Gy of 6 MeV electron beam radiation, immediately after surgery and on the third postoperative day, respectively. Qualitative and histophotometric evaluations of tissue repair structures were carried out. Data were analyzed by ANOVA and Tukey's test (alpha = 0.05) and regression analysis. The repair process was delayed since the first sacrifice time in both irradiated groups, but in IG1, wound healing was closer to that of CG1; whereas in IG2, the delay was more pronounced. Based on the histological findings, it is possible to conclude that a low-dose of electron radiation delayed tissue repair in rat skin. The delay was longer in the skin irradiated 3 days after the beginning of tissue repair. However, the low-energy electron irradiation did not prevent wound healing.