Is the assessment of the mandibular molar danger zone affected by field of view and voxel size in cone beam computed tomography examinations?

OBJECTIVE: To verify if assessment of the danger zone (DZ) in the mesial root of mandibular molars is affected by field of view (FOV) and voxel sizes in cone beam computed tomography (CBCT) scans. STUDY DESIGN: Forty mandibular molars were scanned by micro-computed tomography, creating the reference standard. The teeth were then submitted for CBCT scans with FOVs of 10 × 5.5 cm and 5 × 5.5 cm and voxel sizes of 0.4, 0.2, 0.15, and 0.075 mm3. The smallest dentin thickness in the DZ from the mesiobuccal and mesiolingual canals was measured at 2, 4, and 6 mm apical to the root furcation. Descriptive statistics, paired t-tests, and intraclass correlation coefficients were used for statistical analysis with significance established at P < .05. RESULTS: All CBCT measurements overestimated the DZ dentin thickness (P < .001) compared to the reference standard. The greatest overestimation occurred in the 5 × 5.5 cm FOV with 0.4 mm3 voxels (P = .007). Dentin thickness measured with the 5 × 5.5 cm FOV and 0.075 mm3 voxels was significantly smaller and produced the best ICC value with the reference standard (0.936). CONCLUSIONS: CBCT overestimates the dentin thickness of the DZ regardless of FOV and voxel sizes. The 5 × 5.5 cm FOV showed the best performance with the 0.075 mm3 voxel size, but it performed poorly with 0.4 mm3 voxels.

Assessing the Impact of the Metal Artifact Reduction Tool on Detecting Furcation Lesions in Maxillary Molars with Different Intracanal Posts: An Ex Vivo Cone-beam Computed Tomography Study.

INTRODUCTION: Considering the potential image compromise and diagnostic challenges posed by metals, this study aimed to assess the efficacy of the metal artifact reduction (MAR) tool in cone-beam computed tomography examinations for detecting furcation lesions in upper molars treated endodontically and restored with different intracanal posts. METHODS: This ex vivo study used 45 endodontically treated maxillary first molars, categorized into the following3 groups (n = 15): control (without intracanal post), metal post, and fiberglass post. Simulations were conducted in the laboratory to replicate alveolar bone, periodontal ligament, and grade I, II, and III furcation lesions. Cone-beam computed tomography scans were obtained with and without the MAR tool, and the furcation lesions were evaluated considering a 5-point Likert scale. Data were analyzed at 5%. RESULTS: In the control group, there was no influence of MAR (P > .05); grade II lesions were not diagnosed, and grade III lesions were the most detected (P < .05). In the metal post group with MAR, grade III lesions were diagnosed more frequently than I and II (P < .05) and grade III without MAR (P < .05). In the fiberglass post group, the diagnosis of grade I lesions decreased with MAR (P < .05), and without MAR, grade III was most diagnosed (P < .05); grade III lesions were the most diagnosed (P < .05). CONCLUSIONS: The MAR tool was only effective for diagnosing grade III furcation lesions, regardless of the intracanal material. Its application for grade I and II lesions did not contribute to improved diagnosis. Furthermore, in the fiberglass post group with grade I lesions, the MAR tool negatively affected the detection of the lesions.

Fracture resistance of weakened roots restored with relined or milled CAD-CAM glass fiber posts.

This in vitro study compared the fracture resistance of weakened roots restored with milled or relined glass fiber post (GFP). Seventy bovine incisors were divided into seven groups, according to the weakening protocol (none: control; medium-weakened: MW; highly-weakened: HW) and post anatomization technique (non-relined, relined with Bulk Fill or Z350 resin; milled GFP: M). Roots were thermomechanical cycled and submitted to compression. Frequencies and groups were compared by the chi-square test and two-factor ANOVA, Tukey's, and t-test (α=5%). The HW-M obtained the lowest values, showing significant differences compared to all groups (p<0.001). The highest value was HW-Bulk fill, with significant difference compared to MW-M (p=0.037) and HW-M (p<0.001). The frequency of repairable fractures was 100% in the control, 87%, and 63% in the MW and HW, respectively. Relined or milled GFPs can be considered to rehabilitate weakened teeth since failure patterns were predominantly repairable in all groups.

The effectiveness of EDTA 17% as a cleaning solution for the fiber post space after filling with cements

Aim: To evaluate the resistance of the union between a glass fiber post and radicular dentine after cleaning the root with 17% EDTA and filling with different endodontic cements. Methods: Forty uniradicular bovine incisors were removed to obtain root lengths of 18 mm. Endodontic treatment was performed on all roots using different filling cements (zinc oxide and eugenol-based, OZE; cement based on epoxy resin, AH) and cleaning solutions (saline, SA or EDTA), which made it possible to obtain four groups: OZESA, OZEEDTA, AHSA and AHEDTA. Subsequently, 12 mm of filling material was removed from the roots, and they were prepared to receive fiber posts luted with resin cement. To execute the mechanical cycles (2x106 cycles, 90 N, 4 Hz), coronal reconstruction was performed with a silicon matrix. The roots were then sliced (2-mm thick) to perform the push-out test. The results were analyzed using analysis of variance (one factor and two factors) and Tukey's test (α=0,05). Results: Bond strength (Mpa) was significantly higher for OZEEDTA (9,18) and AHEDTA (8,70) than for OZESA (6,06) AHSA (8,7). OZEEDTA also presented the highest values in the cervical region (15,18) but was significantly lower in the apical region (2,99). However, AHEDTA had a homogeneous bond strength in all thirds. Conclusion: Regardless of the endodontic cement used, EDTA was used as an irrigating solution, culminating in a higher bond strength between the glass fiber post and dentin

Evaluation of the Maxillary Sinus of Patients with Maxillary Posterior Implants: A CBCT Cross-Sectional Study.

BACKGROUND: During oral rehabilitation, dental implants in the posterior maxilla can penetrate the maxillary sinus. The aim was to evaluate the presence of maxillary sinus abnormalities in patients with dental implants in the posterior maxillary region using cone-beam computed tomography (CBCT) images. MATERIALS AND METHODS: This was a retrospective cross-sectional study, and CBCT scans of 199 patients (459 dental implants) were evaluated. Implants were assessed according to their relative location to the maxillary sinus floor (up to 2 mm from the maxillary sinus cortex, within 2 mm to intimate contact with the maxillary sinus cortex, apical third inside the maxillary sinus, two-thirds or more inside the maxillary sinus) and bone-fixation tissue (Alveolar ridge or Bone graft). Maxillary sinus abnormalities were classified. Kappa and Weighted Kappa and the Kruskal-Wallis test were applied. RESULTS: A higher prevalence of mucosal thickening and non-specific opacification were observed in implants located within 2 mm to intimate contact with the cortex of the maxillary sinus floor. Of the 66 implants with apical thirds located inside the maxillary sinus, 31 (46.7%) were associated with sinus abnormalities and of all implants (n = 5) with two-thirds or more located inside the maxillary sinus, all of these were associated with sinus abnormalities. No association was observed in relation to implant bone-fixation tissue. CONCLUSIONS: This study found a significant association between dental implant placement near or within the sinus and sinus abnormalities, mainly mucosal thickening and non-specific opacification.

Is a fiber post better than a metal post for the restoration of endodontically treated teeth? A systematic review and meta-analysis.

OBJECTIVE: To evaluate systematically the evidence about the failure rates of endodontically treated teeth (ETT) restored with intraradicular metal posts (MPs) or fiber posts (FPs). DATA: The review protocol was registered on PROSPERO (CRD42020189792). Eligibility criteria included randomized clinical trials (RCT) and prospective clinical trials (PCT) that compared the failures between FP and MP restorations for ETT. Meta-analyses were conducted for failure rates using fixed- and random-effects models. Subgroup and funnel plot analyses were performed. SOURCES: Four electronic databases (MEDLINE/PubMed, Web of Science, Scopus, and Cochrane Library), manual, and grey literature were screened by two researchers independently for articles published until November 2020 without language or time restrictions. For the analysis of the risk of bias, the Cochrane collaboration tool and ROBINS-I were used. The certainty of the evidence was evaluated using GRADE. STUDY SELECTION: Ten studies were included. A total of 704 participants with a mean age of 42.7 years with a total of 844 ETT were restored using 453 FPs and 391 MPs. The FPs presented similar failures to that with MPs (P=0.39; risk ratio [RR]:0.82; 95% confidence interval [CI]: 0.52 to 1.29). Subgroup analysis showed no significant differences between the FPs and MPs for the anterior region (P=0.60; RR:0.88; [CI]: 0.54 to 1.42), posterior region (P=0.52; RR:1.18; [CI]: 0.71 to 1.98), root fracture (P=0.44; RR:0.78; [CI]: 0.41 to 1.49), and debonding (P=0.56; RR:1.27; [CI]: 0.57 to 2.80). Additionally, FP showed similar failures compared with those of cast (P=0.36; RR:0.63; [CI]: 0.23 to 1.72) and prefabricated MPs (P=0.68; RR:0.90; [CI]: 0.54 to 1.50). The RCT and PCT studies revealed a low risk of bias for most of the domains. However, the certainty of evidence was considered low. CONCLUSION: No evidence of difference was observed for failure rates between FPs, and MPs, independent of region and different MPs used in ETT. However, further well-conducted clinical studies with high-quality evidence are encouraged. CLINICAL SIGNIFICANCE: Our results indicate that both retainer posts can be considered an adequate alternative in restoring ETT. Therefore, the choice of post (fiber or metal) could be based on dentist preference or individual characteristics of the patient as the failure rates for different posts are similar.

Assessment of the Metal Artifact Reduction Tool for the Detection of Root Isthmus in Mandibular Molars with Intraradicular Posts in Cone-beam Computed Tomographic Scans.

INTRODUCTION: This study evaluated the performance of the metal artifact reduction (MAR) tool in cone-beam computed tomographic scans using different fields of view (FOVs) in the detection of a root isthmus in mandibular molars with intraradicular posts. METHODS: Twenty-eight teeth were scanned by micro-computed tomographic imaging (gold standard images). Thereafter, specimens were allocated into the following groups: gutta-percha (teeth without posts, n = 10), a prefabricated metal post (n = 9), and a fiberglass post (n = 9). Cone-beam computed tomographic scans were taken using 8 acquisition protocols, varying the size of the FOV (10 × 5.5 cm and 5 × 5.5 cm) and the MAR tool (disabled, low, normal, and high modes). A root isthmus was evaluated considering a 5-point scale. Data were analyzed considering a 5% significance level. RESULTS: Intra- and interexaminer agreement varied from moderate to substantial. The frequency of correct diagnosis varied significantly in all groups regardless of the image acquisition protocol selected (P < .05). In the gutta-percha group, there was no difference in the accuracy, sensitivity, and specificity values between the tested protocols. In the metal and fiberglass post groups, the accuracy values were higher with the "disabled" and "low" modes of the MAR tool regardless of the FOV size. This was also observed for the sensitivity values in the metal post group (P < .05). CONCLUSIONS: The size of the FOV did not affect the performance of the MAR tool in the diagnosis of a root isthmus in molars with intraradicular posts. Our findings suggest that the use of the tool in the "normal" and "high" modes is contraindicated for this purpose.

Evaluation of The Cleaning Protocol of Post Space on Bond Strength of Glass Fiber Posts

ABSTRACT: This study aimed to compare the effect of four irrigation solutions for post space cleaning on the bond strength between glass fiber post and root dentine. Forty bovine roots were root-filled and randomly divided into four groups (n=10), according to the irrigation solution: CG (Control Group): saline solution; SH (Sodium Hypochlorite Group); CLX (Chlorhexidine group) and EDTA (ethylenediaminetetraacetic acid group). Specimens were submitted to mechanical aging and push-out test. Statistical analysis (ANOVA two-way and Tukey test; p<0.05) was performed. A stereomicroscope was used for failure mode classification. EDTA showed higher bond strength values, differing statistically from SH and CG (p<0.05). Adhesive failure between dentin and resinous cement was predominant, followed by mixed failures. SEM images showed pronounced smear layer removal in the EDTA group. 17 % EDTA was better than other solutions for cleaning of post space when using glass fiber posts.

RESUMEN: Este estudio tuvo como objetivo comparar el efecto de cuatro soluciones de irrigación para la limpieza del espacio del poste sobre la fuerza de unión entre el poste de fibra de vidrio y la dentina radicular. Se rellenaron cuarenta raíces bovinas y se dividieron aleatoriamente en cuatro grupos (n = 10), según la solu- ción de riego: CG (Grupo Control): solución salina; SH (Gru- po de hipoclorito de sodio); CLX (grupo clorhexidina) y EDTA (grupo ácido etilendiaminotetraacético). Las muestras se sometieron a una prueba de envejecimiento mecánico y de expulsión. Se realizó análisis estadístico (ANOVA bidireccional y prueba de Tukey; p <0,05). Se utilizó un microscopio estereoscópico para la clasificación del modo de falla. EDTA mostró valores de fuerza de unión más altos, difiriendo estadísticamente de SH y CG (p <0,05). Pre-dominó la falla adhesiva entre dentina y cemento resinoso, seguida de fallas mixtas. Las imágenes SEM mostraron una eliminación pronunciada de la capa de frotis en el grupo de EDTA. El EDTA al 17 % fue mejor que otras soluciones para la limpieza del espacio de los postes cuando se utilizan postes de fibra de vidrio.

Morphometric analysis of the mandibular fossa in dentate and edentulous patients: A cone beam computed tomography study.

STATEMENT OF PROBLEM: Mandibular fossa roof thickness and lateral inclination could be associated with the presence of bone changes in the mandibular condyle in dentate and edentulous patients. However, literature regarding the relationship between the presence and absence of teeth and the morphologic features of the temporomandibular joint is lacking. This knowledge could provide a better understanding of changes affecting the correct functioning of the stomatognathic system. PURPOSE: The purpose of this clinical study was to assess the mandibular fossa roof thickness and lateral inclination in relation to sex, presence or absence of teeth, and bone changes in the mandibular condyle through cone beam computed tomography (CBCT). MATERIAL AND METHODS: CBCT scans of 100 individuals (50 dentate and 50 edentulous) were evaluated in terms of mandibular fossa roof thickness and lateral inclination. Bone changes in the mandibular condyle were classified dichotomously in relation to osteophytes, erosion, sclerosis, and flattening. Differences were assessed with the Student t test, the chi-square test, and 2-way analysis of variance (ANOVA), with Tukey post hoc tests (α=.05). RESULTS: Sex was not related to mandibular fossa measurements. Edentulous participants showed a higher mandibular fossa lateral inclination (P<.001) and lower roof thickness (P=.001) than dentate participants. When the association between bone changes in the mandibular condyle was evaluated in dentate and edentulous groups, only sclerosis showed a statistically significant association (P<.001). The 2-way ANOVA showed that the mandibular fossa roof thickness was lower in edentulous participants in the presence of flattening and erosion and that the mandibular fossa lateral inclination was higher in the presence of osteophytes, erosion, and sclerosis (P<.001). Among dentate participants, the mandibular fossa lateral inclination was higher in the presence of flattening (P=.024). CONCLUSIONS: Mandibular fossa roof thickness and lateral inclination are not associated with sex. However, tooth absence and bone changes in the mandibular condyle are related to mandibular fossa measurements.

Missed canals in endodontically treated maxillary molars of a Brazilian subpopulation: prevalence and association with periapical lesion using cone-beam computed tomography.

OBJECTIVES: To evaluate the prevalence of missed canals in endodontically treated maxillary molars through cone-beam computed tomography (CBCT) images and to verify their association with the presence of periapical lesions. MATERIAL AND METHODS: Three oral radiologists evaluated 633 maxillary molars in CBCT exams regarding number of roots, number of root canals, number of missed canals, anatomic identification of missed canals, presence of periapical lesions, and root location of the periapical lesions. Data were statistically analyzed at a 5% significance level. RESULTS: Descriptive statistical analysis showed that among 395 first molars, 218 had at least one missed canal, and 186 (46.5%) had a missed canal and periapical lesion simultaneously. Of these, 72.4% (134) of the missed canals were only mesiobuccal 2 (MB2). Among 238 s molars evaluated, 121 presented at least one missed canal, and 104 (43.6%) had a missed canal and periapical lesion simultaneously. Of these, 81.7% (85) of the missed canals were only MB2. The chi-squared test showed an association between the presence of missed canals and periapical lesions for 1st and 2nd maxillary molars. Teeth that presented a missed canal showed an odds ratio (OR) of 2.57 (p < 0.0001) of being associated with a periapical lesion. Missed canal occurrence was positively related to the number of root canals (z = 13.06, p < 0.0001), meaning when the number of root canals is higher, there is a higher probability of missed canal occurrence. According to the model calculated prediction, for a one-unit increase in the number of canals, the probability of missed canals increases by 4.22%. CONCLUSIONS: It was concluded that MB2 was the most frequently missed canal, associated with the presence of periapical lesions in endodontically treated maxillary molars. CLINICAL RELEVANCE: Professionals' negligence of anatomical root variations has been contributed to the high prevalence of missed canals, leading to failures in endodontic treatment. Their association with periapical lesion occurrence emphasizes the importance of correct detection and instrumentation of these canals.

Anatomical evaluation of the relationship between the maxillary posterior teeth and maxillary sinus.

Knowledge of the anatomical relationships between the maxillary sinus (MS) and posterior teeth is important to prevent complications when endodontic or oral surgical procedures are performed. The aim of this study was to evaluate the relationships between the root apices of maxillary posterior teeth and the MS floor. Three oral radiologists evaluated 851 posterior teeth (1969 roots) imaged with cone beam computed tomography. The roots were analyzed individually in parasagittal sections, on which the most superior point of the apex was observed. A qualitative evaluation was performed, and each root was assigned a proximity score: 1, root invaginating the MS; 2, root in close contact with the MS floor; 3, root with no relationship with the MS; and 4, root with a measurable proximity to the MS. For roots classified as score 4, the distance to the MS floor was measured (quantitative analysis). Student t tests, 1-way analysis of variance, and simple linear regression analysis were performed (P < 0.05). The qualitative analysis revealed that the mesiobuccal root of the second molar had a pronounced proximity to the MS. The quantitative analysis revealed no differences in distance to the MS between right and left posterior teeth or between the different roots of the same tooth. In relation to the MS, the second molar was positioned closest, followed by the first molar, second premolar, and first premolar. Except for the comparison between mean distances of the second premolar and first molar (P = 0.11), the differences between groups of teeth were statistically significant (P < 0.05). Simple linear regression analysis showed that the more posterior the tooth was in relation to the midline, the shorter the mean distance from the root apex to the MS floor (P < 0.05). The mesiobuccal roots of second molars were closest to the MS. Second molars exhibited the shortest distances between their root apices and the MS and the greatest number of roots that were invaginating or in close contact with the MS. Therefore, second molars require special attention when endodontic or oral surgical approaches involve those regions.

Dental students' ability to detect maxillary sinus abnormalities: A comparison between panoramic radiography and cone-beam computed tomography.

PURPOSE: To compare the diagnostic ability of undergraduate dental students to detect maxillary sinus abnormalities in panoramic radiographs (PR) and cone-beam computed tomography (CBCT). MATERIALS AND METHODS: This was a retrospective study based on the evaluation of PR and CBCT images. A pilot study was conducted to determine the number of students eligible to participate in the study. The images were evaluated by 2 students, and 280 maxillary sinuses were assessed using the following categories: normal, mucosal thickening, sinus polyp, antral pseudocyst, nonspecific opacification, periostitis, antrolith, and antrolith associated with mucosal thickening. The reference standard was established by the consensus of 2 oral radiologists based on the CBCT images. The kappa test, receiver operating characteristic curves, and 1-way analysis of variance with the Tukey-Kramer post-hoc test were employed. RESULTS: Intraobserver and interobserver reliability showed agreement ranging from substantial (0.809) to almost perfect (0.922). The agreement between the students' evaluations and the reference standard was reasonable (0.258) for PR and substantial (0.692) for CBCT. Comparisons of values of sensitivity, specificity, and accuracy showed that CBCT was significantly better (P<0.05). CONCLUSION: CBCT was better than PR for the detection of maxillary sinus abnormalities by dental students. However, CBCT should only be requested after a careful analysis of PR by students and more experienced professionals.

Periapical and Endodontic Status Scale for Endodontically Treated Teeth and Their Association with Maxillary Sinus Abnormalities: A Cone-beam Computed Tomographic Study.

INTRODUCTION: This retrospective cross-sectional study investigated the applicability of the periapical and endodontic status scale (PESS) to determine the association of endodontically treated teeth with maxillary sinus (MS) abnormalities through cone-beam computed tomographic imaging. METHODS: A total of 631 endodontically treated teeth were analyzed. MS abnormalities were classified as mucosal thickening, sinus polyp, antral pseudocyst, nonspecific opacification, periostitis, and antral calcification. The PESS was used to evaluate the quality of endodontic treatment as well as periapical tissue conditions. The data were analyzed by chi-square tests (P < .05). RESULTS: MS abnormalities were detected in 70.52% of the sample, with a greater prevalence of mucosal thickening (38.19%), whereas periapical lesions were observed in 55.94% of the cases. Treated root canals with unsatisfactory filling, homogeneity, and coronal sealing had an odds Ratio (OR) of 2.21, 2.88, and 2.99, respectively (P < .001). Periapical lesions larger than 5 mm (OR = 314.95), in more than 1 root (OR = 3.72), involving the furcation region (OR = 5.21), in contact with important structures (OR = 7.37), and with cortical bone destruction (OR = 4.09) were significantly related to the presence of MS abnormalities (P < .001). An OR of 99,668 was observed in periostitis lesions greater than 5 mm (P < .001). CONCLUSIONS: The PESS proved to be an important tool for the analysis of endodontic and periapical conditions and was applicable to determine potential associations with MS abnormalities.

Effectiveness of Using a Mobile App to Improve Dental Students' Ability to Identify Endodontic Complications from Periapical Radiographs.

The aim of this study was to evaluate the feasibility and effectiveness of a mobile application as a supplementary tool in the radiographic diagnosis of endodontic complications by dental students. Radiographic images of the following endodontic conditions were selected: 1) absence of endodontic treatment (ET) without periapical lesion (PL); 2) absence of ET with PL; 3) satisfactory ET without PL; 4) satisfactory ET with PL; 5) unsatisfactory ET without PL; 6) unsatisfactory ET with PL; 7) fractured instrument; 8) deviated cast post; 9) root fracture; and 10) root resorption. In 2018, images were evaluated by 20 students at a dental school in Brazil who had been divided into experimental and control groups. The experimental group was permitted to use the Kahoot! mobile application (app) to access reference images of endodontic conditions. Reference standards were established through consensus by two endodontists and three oral radiologists. The results showed that intraobserver agreement ranged from moderate to substantial for both groups. Significant differences from the specialists' reference standards were found in the evaluation of conditions 4 and 10 for the experimental group, which used the app (p<0.001), and conditions 1, 4, 6, 7, 8, and 10 for the control group, which did not use the app (p<0.05). No statistically significant differences were found in accuracy, sensitivity, or specificity values between the groups for any of the endodontic conditions evaluated (p>0.05). This study found that the use of a mobile app containing reference images improved the students' ability to diagnose endodontic complications, suggesting it would be a valuable supplementary tool in dental education.

Intrusive Dislocation in Permanent Teeth: Review of Literature and Clinical Case Report / Luxación Intrusiva en Dientes Permanentes: Revisión de Literatura e Informe de Caso Clínico

ABSTRACT: Intrusive dislocation is an unusual and severe trauma, where the tooth is displaced axially into the alveolar bone, causing damage to the periodontal and pulpal tissues. The objective was to report a case of intrusive dislocation on a right maxillary central incisor of a 12-year-old patient, where the proposed treatment was immediate surgical repositioning. Clinical and radiographic examination revealed partial tooth intrusion and complete root formation. The impacted tooth was surgically repositioned and immobilized. Subsequently, the endodontic treatment of the tooth associated with intracanal medication was performed. After 10 months of successive calcium hydroxide changes, the root canal system was filled. Clinical-radiographic follow-ups were performed over 5 years and 7 months, revealing discrete root resorption. It was concluded that immediate surgical repositioning, associated with adequate root canal therapy may be an effective therapeutic option in cases of intrusive dislocation of permanent teeth.

RESUMEN: La luxación intrusiva es un trauma inusual y severo, en el que el diente se desplaza axialmente hacia el hueso alveolar, causando daño a los tejidos periodontales y pulpares. El objetivo fue informar un caso de luxación intrusiva en un incisivo central superior derecho de un paciente de 12 años, donde el tratamiento propuesto fue el reposicionamiento quirúrgico inmediato. El examen clínico y radiográfico reveló una intrusión dental parcial y la formación completa de la raíz. El diente afectado fue reposicionado e inmovilizado quirúrgicamente. Posteriormente, se realizó el tratamiento endodóntico del diente asociado con la medicación intracanal. Después de 10 meses de sucesivos cambios de hidróxido de calcio, se llenó el sistema de conductos radiculares. Los seguimientos clínico-radiográficos se realizaron durante 5 años y 7 meses, revelando la resorción discreta de la raíz. Se concluyó que el reposicionamiento quirúrgico inmediato, asociado con la terapia adecuada del conducto radicular, puede ser una opción terapéutica efectiva en casos de luxación intrusiva de dientes permanentes.

Detection of an unusual inverted schneiderian papilloma by cone beam computed tomography.

An inverted schneiderian papilloma (ISP) is a rare neoplasm that affects the nasal cavity or a paranasal sinus, especially the maxillary sinus. Although histologically benign, the lesion has a high potential for local destruction, has a high recurrence rate, and presents the possibility of malignant transformation into squamous cell carcinoma. To determine the extent of the injury and possible impairment of adjacent maxillofacial structures, accurate imaging, such as cone beam computed tomography (CBCT), is necessary. A 47-year-old man reported a nasal obstruction on the right side of his face, signs of oroantral communication, and facial asymmetry. The CBCT examination revealed an extensive lesion of mixed density and irregular contours involving the entire right maxillary sinus and nasal cavity. The association between the clinical signs and symptoms and the tomographic features of the lesion resulted in a differential diagnosis of an ISP, which was confirmed through histopathologic examination. This case report confirms that CBCT is a valuable method for the detection of pathologic alterations affecting the maxillary sinus, especially ISPs.

Ankylosis of Permanent First Molar: Diagnosis by Cone Beam Computed Tomography / Anquilosis del Primer Molar Permanente: Diagnóstico por Tomografía Computarizada con Haz Cónico

ABSTRACT: Ankylosis is an anomaly of tooth eruption characterized by the fusion of cementum and alveolar bone, and may affect from small regions to the entire root surface. Clinical assessment combined with imaging exams can aid diagnosis. Radiographic testing enables assessing only proximal regions of possibly affected roots. Whereas cone beam computed tomography (CBCT) allows a three-dimensional assessment of axial, coronal, and sagittal planes of all dental extension, eliminating thus overlapping images and helping to confirm the correct diagnosis. The present study contains a case report of a male patient with ankylosis in tooth 16 diagnosed by CBCT, aiming at providing information for dentists about this anomaly, its characteristics and situations in which CBCT should be indicated.

RESUMEN: La anquilosis es una anomalía de la erupción del diente caracterizada por la fusión de cemento y hueso alveolar, y puede afectar desde pequeñas regiones hasta toda la superficie de la raíz. La evaluación clínica combinada con los exámenes de imagen puede ayudar a diagnosticar esta anomalía. Las pruebas radiográficas permiten evaluar sólo las regiones proximales de las raíces posiblemente afectadas. La tomografía computarizada de haz de cono (CBCT) permite una evaluación tridimensional de los planos axial, coronal y sagital de toda la extensión dental, eliminando así las imágenes superpuestas y ayudando a confirmar el diagnóstico correcto. En el presente estudio se presenta un reporte de caso de un paciente con anquilosis en el diente 16 diagnosticado por CBCT, con el objetivo de proporcionar información para los dentistas sobre esta anomalía, sus características y situaciones en las que debe indicarse la CBCT.

Características epidemiológicas de pacientes portadores de neoplasias de cabeça e pescoço submetidos à radioterapia em Juiz de Fora ­ MG / Epidemiological aspects of patients with head and neck neoplasms undergoing radiotherapy in Juiz de Fora - MG

A neoplasia de cabeça e pescoço é o sexto tipo de câncer mais comum no mundo. As neoplasias malignas maxilofaciais, em sua maioria, se iniciam nas células escamosas que revestem as superfícies mucosas da região. O objetivo no presente estudo foi realizar um levantamento epidemiológico sobre neoplasias de cabeça e pescoço em pacientes que se submeteram à radioterapia em um hospital de alta complexidade oncológica da cidade de Juiz de Fora, Minas Gerais (MG). Foram incluídos na análise prontuários de pacientes, de ambos os sexos, de todas as faixas etárias e etnias, com diagnóstico de neoplasias de cabeça e pescoço e que estiveram sob tratamento de radioterapia no período de janeiro a setembro de 2015, no Hospital ASCOMCER, situado em Juiz de Fora (MG). A idade dos pacientes acometidos com neoplasias de cabeça e pescoço variou de 39 a 88 anos, com idade média de 59,78 (±12,49) anos, e faixa etária de 61 a 70 anos apresentando prevalência das alterações. Em relação ao sexo, observou-se uma maior prevalência das lesões neoplásicas em homens (64,3%) do que em mulheres (35,7%). Em relação ao sitio anatômico primário, a laringe foi o local mais prevalente (17,9%) e o lábio inferior (3,6%), assoalho bucal (3,6%) e glote (3,6%) os menos prevalentes. Observou-se um maior número de pacientes sem comprometimento dos linfonodos regionais (53,6%), do que pacientes com comprometimento (46,4%). Este estudo forneceu o perfil epidemiológico dos pacientes portadores de neoplasias de cabeça e pescoço, e que necessitaram de tratamento com radioterapia, no referido hospital. Tal delineamento epidemiológico é fundamental para auxiliar no planejamento de ações de prevenção futuras na cidade de Juiz de Fora.

Detection of Fractured Endodontic Instruments in Root Canals: Comparison between Different Digital Radiography Systems and Cone-beam Computed Tomography.

INTRODUCTION: This study compared the detection of fractured instruments in root canals with and without filling by periapical radiographs from 3 digital systems and cone-beam computed tomographic (CBCT) images with different resolutions. METHODS: Thirty-one human molars (80 canals) were used. Root canals were divided into the following groups: the control group, without fillings; the fracture group, without fillings and with fractured files; the fill group, filled; and the fill/fracture group, filled and with fractured files. Digital radiographs in ortho-, mesio-, and distoradial directions were performed in 2 semidirect systems (VistaScan [Dürr Dental, Beitigheim-Bissinger, Germany] and Express [Instrumentarium Imaging, Tuusula, Finland]) and a direct system (SnapShot [Instrumentarium Imaging]). CBCT images were acquired with 0.085-mm and 0.2-mm voxel sizes. All images were assessed and reassessed by 4 observers for the presence or absence of fractured files on a 5-point scale. The sensitivity, specificity, and accuracy were calculated. RESULTS: In the absence of filling, accuracy values were high, and there were no statistical differences among the radiographic techniques, different digital systems, or the different CBCT voxels sizes. In the presence of filling, the accuracy of periapical radiographs was significantly higher than CBCT images. In general, SnapShot showed higher accuracy than VistaScan and Express. CONCLUSIONS: Periapical radiographs in 1 incidence were accurate for the detection of fractured endodontic instruments inside the root canal in the absence or presence of filling, suggesting that this technique should be the first choice as well as the direct digital radiographic system. In the presence of filling, the decision to perform a CBCT examination must take into consideration its low accuracy.