Abstract The site of the sinus tract depends on the rate of resistance against abscess exudate drainage, bone morphology, and distance from the root apex to the outer cortical bone. Objective To assess apical bone thickness in buccal and palatal/lingual aspects of maxillary and mandibular teeth, using a high-resolution cone-beam computed tomography (CBCT) system. Methodology In total, 422 CBCT examinations were included in the study, resulting in a sample of 1400 teeth. The scans were acquired by PreXion 3D, with a high-resolution protocol. The bone thickness was taken as the distance between the center of the apical foramen and the buccal and lingual/palatal cortical bone. The quantitative variables were expressed as mean values±standard deviation. The independent samples were analyzed using the t-test or the Mann-Whitney test (p<0.05). Results The lowest mean value of bone thickness was observed in the buccal cortical bone of the upper canines (1.49 mm±0.86) and in the upper central incisors (1.59 mm±0.67). In premolar teeth, the lowest values were found in the buccal cortical bone of upper first premolars (1.13 mm±0.68). In the posterior teeth, the lowest values were found in the buccal cortical bone of upper first molars (1.98 mm±1.33). In the lower second molar region, the buccal cortical bone (8.36 mm±1.84) was thicker than the lingual cortical bone (2.95 mm±1.16) (p<0.05). Conclusions The lowest mean values of bone thickness are in the buccal cortical bone of the maxillary teeth. In the mandible, bone thickness is thinner in the buccal bone around the anterior and premolar teeth, and in the lingual aspect of mandibular molars. All these anatomic characteristics could make the occurrence of the sinus tract more susceptible in these specific regions of the maxillary and mandibular alveolar bone.

OBJECTIVE:To evaluate the discrepancy of root canal filling (RCF) measurements obtained from original root specimens and cone-beam computed tomography (CBCT) images. MATERIAL AND METHODS: Seventy-two human maxillary anterior teeth were prepared up to an ISO #50 K-File 1 mm short of the apical foramen. Thus, the teeth were randomly divided into 8 groups, according to the root canal filling material: Sealapex ®, Sealapex®+gutta-percha points, Sealer 26®, Sealer 26®+gutta-percha points, AH PlusTM, AH PlusTM+gutta-percha points, Grossman Sealer, and Grossman Sealer+gutta-percha points. After root canal preparation and RCF, CBCT scans were acquired and the specimens were sectioned in axial, sagittal and coronal planes. The RCF measurements were obtained in different planes and thicknesses to determine the discrepancy between the original root specimens (using a digital caliper) and the CBCT images (using the scanner’s proprietary software). One-way analysis of variance and Tukey tests were used for statistical analyses. The significance level was set at α=5%. RESULTS: Measurements of the different endodontic filling materials were 9% to 100% greater on the CBCT images than on the original root specimens. Greater RCF dimensions were found when only sealers were used, with statistically significant difference among the groups. CONCLUSIONS: RCF dimensions were greater on CBCT images than on the original root specimens, especially when only sealer was used.

O objetivo deste estudo foi determinar a influência de retentores intraradiculares na periodontite apical (PA), detectados por radiografia periapical (RP) e tomografia computadorizada de feixe cônico (TCFC). Um total de 1.020 imagens, tomadas de 619 pacientes (245 homens, idade média de 50,1 anos), entre Fevereiro de 2008 e Setembro de 2009, foram avaliadas. A presença e o comprimento de retentores intraradiculares (curto, médio e longo) foram associados com a PA. Os dados foram estatisticamente avaliados empregando-se os testes Qui-quadrado e o Kappa. Três observadores avaliaram todas as imagens, considerando-se a presença de retentor intraradicular, seu comprimento e a PA. De um total de 1.020 dentes analisados no estudo, a PA foi detectada em 397 (38,92%) usando RP e em 614 (60,19%) usando TCFC (p<0,001). Em 591 retentores intraradiculares, nos diferentes comprimentos (curto, médio, longo) foram observadas PA usando RP em 15,06%; 18,78% e 7,95%, respectivamente (p=0,466). Considerando os mesmos comprimentos de retentores foram observados PA em 24,20%; 26,40% e 11,84% por meio de TCFC, respectivamente (p=0,154). A distribuição de retentores nos diferentes grupos dentários mostrou elevada prevalência em dentes anteriores superiores (54,79%). Os retentores intraradiculares não influenciaram a PA e as TCFC detectaram mais freqüentemente a periodontite apical.

The determination of the success of endodontic treatment has been often discussed based on outcome obtained by periapical radiography. The aim of this study was to verify the influence of intracanal post on apical periodontitis detected by cone-beam computed tomography (CBCT). A consecutive sample of 1020 images (periapical radiographs and CBCT scans) taken from 619 patients (245 men; mean age, 50.1 years) between February 2008 and September 2009 were used in this study. Presence and intracanal post length (short, medium and long) were associated with apical periodontitis (AP). Chi-square test was used for statistical analyses. Significance level was set at p<0.01. The kappa value was used to assess examiner variability. From a total of 591 intracanal posts, AP was observed in 15.06%, 18.78% and 7.95% using periapical radiographs, into the different lengths, short, medium and long, respectively (p=0.466). Considering the same posts length it was verified AP in 24.20%, 26.40% and 11.84% observed by CBCT scans, respectively (p=0.154). From a total of 1,020 teeth used in this study, AP was detected in 397 (38.92%) by periapical radiography and in 614 (60.19%) by CBCT scans (p<0.001). The distribution of intracanal posts in different dental groups showed higher prevalence in maxillary anterior teeth (54.79%). Intracanal posts lengths did not influenced AP. AP was detected more frequently when CBCT method was used.