SUMMARY Coronavirus disease (COVID-19) is highly transmissible through respiratory droplets, saliva, and aerosol particles. Infection can lead to severe acute respiratory syndrome and trigger multi-organ failure and death. Most clinical dental procedures involve contact with saliva or the generation of aerosols with saliva and blood. These airborne particles increase the risk of transmission by COVID-19 between dentists and patients. Thus, dentistry must adopt procedures to reduce transmission during dental procedures. Although these strategies may not be directly applicable to all institutions due to cultural, social, geographical, and economic differences, the underlying principles and implemented strategies remain relevant and can be adopted or modified by the institutions dealing with the current COVID-19 outbreak. The purpose of this article is to discuss one of the principal sources of COVID-19 transmission: saliva, the biofluid most frequently handled in a radiology environment. The authors also recommend strategies and operational procedures to decrease the spread of COVID-19 in a radiological routine.

RESUMEN La enfermedad por coronavirus (COVID-19) se transmite fácilmente a través de gotitas respiratorias, saliva y partículas de aerosol. La infección puede desencadenar un síndrome respiratorio agudo severo, insuficiencia multiorgánica y, en algunos casos, la muerte. Los procedimientos clínicos dentales determinan el contacto con saliva o la generación de aerosoles con saliva y sangre, lo que implica un alto riesgo de transmisión por COVID-19 entre odontólogos y pacientes. Por ello, la práctica odontologica debe adoptar medidas para detener la propagación durante los procedimientos dentales. En este artículo se revisan las estrategias para mitigar el riesgo de transmisión de COVID-19. Si bien estas estrategias pueden no ser directamente aplicables a todas las instituciones debido a diferencias culturales, sociales, geográficas y económicas inherentes, los principios subyacentes y las estrategias implementadas siguen siendo relevantes y pueden ser adoptados o modificados por las instituciones que se ocupan del brote actual de COVID-19. El propósito de este artículo es discutir una de las principales fuentes de transmisión de COVID-19: la saliva, el biofluido que se maneja con mayor frecuencia en un entorno radiológico. Los autores también recomiendan estrategias y procedimientos operativos para disminuir la propagación de COVID-19 en una rutina radiológica.

Resumo Este estudo avaliou a ação da radiação ionizante e o possível efeito radioprotetor do anti-inflamatório não esteroide meloxicam na fisiologia óssea de mandíbulas de rato por meio da análise da reparação alveolar e da resistência óssea. Quarenta ratos Wistar machos foram divididos em 4 grupos (n=10): controle (GC), irradiado (GI), meloxicam (GM), meloxicam irradiado (GMI). Administrou-se uma dose única de 0,2 mg/kg de meloxicam no GM e GMI. Posteriormente, o GI e GMI foram irradiados com dose de 15 Gy na região de mandíbula. Decorridos 40 dias dos procedimentos acima, extraiu-se os primeiros molares inferiores dos animais, que foram mortos após 15 e 30 dias (n=5). Utilizou-se a microtomografia computadorizada e o teste de flexão para avaliação da reparação alveolar e da resistência óssea, respectivamente. Aos 15 dias, o volume ósseo, a fração de volume ósseo e a espessura trabecular foram maiores no GC e GM comparados ao GI e GMI; já a separação trabecular foi maior no GI em relação aos demais. Aos 30 dias, houve diferença apenas na separação trabecular, que foi maior no GI em comparação ao GC e GM, não tendo o GMI diferido dos demais. A resistência óssea no GI foi menor em relação ao GC e GM, não tendo o GMI diferido dos demais. Concluiu-se que a radiação ionizante afetou a fisiologia óssea das mandíbulas de rato, promovendo atraso na reparação alveolar e redução da resistência óssea; além disso, o meloxicam, apresentou efeito positivo na separação trabecular da reparação alveolar e na resistência óssea.

Abstract This study evaluated the action of ionizing radiation and the possible radioprotective effect of the non-steroidal anti-inflammatory drug meloxicam on the bone physiology of rat mandibles by assessing the alveolar socket healing and bone strength. Forty male Wistar rats were divided in 4 groups (n=10): control (CG), irradiated (IG), meloxicam (MG), meloxicam irradiated (MIG). A dose of 0.2 mg/kg meloxicam was administered to MG and MIG. After this, IG and MIG were irradiated with 15 Gy radiation dose in the mandible. Forty days after the above procedures, the mandibular first molars were extracted and the animals were killed after 15 or 30 days (n=5). Micro-computed tomography and bending test were used to evaluate alveolar socket healing and bone strength, respectively. At 15 days, bone volume, bone volume fraction and trabecular thickness were higher in the CG and MG than in the IG and MIG; and trabecular separation was higher in the IG compared with the others. At 30 days, there was a difference only in trabecular separation, which was higher in IG than in CG and MG, and MIG did not differ from the others. Bone strength was lower in IG compared with CG and MG, and MIG did not differ from the others. In conclusion, the ionizing radiation affected the bone physiology of rat mandibles, delaying the alveolar socket healing and reducing the bone strength. Moreover, the meloxicam had a positive effect on the trabecular separation in alveolar socket healing and on the bone strength.

<sec><title>Aim:</title><p>To compare the qualitative and quantitative information yielded by imaging modalities on the evaluation of the relationship between the maxillary sinus and the apices of posterior teeth.</p></sec><sec><title>Methods:</title><p>Three oral radiologists examined 109 panoramic radiographs and cone-beam computed tomography (CBCT) images obtained from a digital archive. A total of 1,875 apices were classified according to their topographic relationship in both imaging modalities. Agreements between the two imaging techniques were examined statistically. The evaluation was repeated in 25% of the sample to statistically evaluate the intraobserver agreement, with a 30-day interval.</p></sec><sec><title>Results:</title><p>The values found in the Kappa test for qualitative assessment and the intraclass correlation coefficient (ICC) for quantitative assessment showed nearly perfect and excellent correlation, respectively. Regarding the correlation between the two images, the Kappa test in the quality assessment showed a slight correlation between the palatal roots of the right first molars and second molars. Moreover, the quantitative evaluation by ICC showed poor agreement for the palatal roots of the left first molar and second molar, as well as for the buccomesial of the right second molars and for the buccodistal of the left second molars.</p></sec><sec><title>Conclusions:</title><p>There is low correlation between panoramic radiography and CBCT when roots are in contact or above the maxillary sinus floor. A high level of agreement was observed when roots are below the maxillary sinus floor.</p></sec>

The mandibular canine is a robust and long tooth which allows an adequate implantation in the dental arch. It is considered a valuable pillar in many rehabilitating treatments. In order to maintain this important dental element, it is necessary to make a correct diagnosis, for which the knowledge of the different anatomic variations should be kept in mind. The objective of this article is to present a case of a mandibular canine with two roots with their respective root canals. A 21-year-old female patient went to the Radiology Clinic at the Faculty of Odontology of Piracicaba with the indication of a panoramic radiography for preoperative third molars surgery. An unusual root configuration of the mandibular canines was observed. In the cone beam CT, it was observed that the right mandibular canine presented two separate roots, each one with their respective radicular canals. It was concluded that, despite of the low prevalence of anatomical variations, these can occur in the root system of the mandibular canines, as presented in this case report.

El canino inferior es un diente con raíz larga y ancha que le permite una adecuada implantación en el arco dentario. Es considerado un pilar valioso en muchos tratamientos rehabilitadores. Con la finalidad de mantener este elemento dentario es necesario realizar un correcto diagnóstico, para lo que se tendrá en cuenta el conocimiento de las variaciones anatómicas. El objetivo del artículo es presentar un caso de canino mandibular con dos raíces con sus respectivos canales radiculares .Paciente femenina de 21 años, que acudió a la Clínica de Radiología de la Facultad de Odontología de Piracicaba con indicación de una radiografía panorámica para valorar cirugía de terceros molares. Llamó la atención una configuración inusual de las raíces de los caninos mandibulares. En el examen de tomografía computarizada de haz cónico se observó que el canino mandibular del lado derecho presentaba dos raíces separadas, cada una con sus respectivos canales radiculares. Se concluyó que a pesar de la baja prevalencia de las variaciones anatómicas, estas pueden ocurrir en el número de raíces y canales de los caninos mandibulares, tal como se presenta en este reporte de caso.