The influence of periapical lesions on the repeatability of two electronic apex locators in vivo.

OBJECTIVES: To determine the influence of periapical lesions on the repeatability of two electronic apex locators (EALs), Root ZX II, and RomiApex A-15, in maxillary anterior teeth, in vivo. MATERIALS AND METHODS: After approval by the local ethics committee, 43 maxillary anterior teeth scheduled for root canal therapy were assigned to two groups. The periapical lesion (PAL) group included 21 teeth with necrotic pulps and radiographically visible periapical lesion, and the normal periapex (NPA) group consisted of 22 teeth with vital pulps and no periapical lesion. In each canal, Root ZX II and RomiApex A-15 were used to determine working length defined as the "zero" reading on the display. Two consecutive measurements were performed with each EAL on each tooth and a second operator measured the endodontic file with a digital caliper without knowledge of the EAL being used or the tooth diagnosis. The absolute value of the difference between the first and second measurement (measurement pairs) was calculated. Repeatability was evaluated by the Bland-Altman method, and an aligned ranks transformation ANOVA was conducted to compare the EALs. RESULTS: The median absolute difference between measurement pairs was significantly lower (p < 0.001) and the limits of agreement were narrower in the NPA group. Among the EALs, median absolute differences were significantly smaller for Root ZX (p < 0.001). CONCLUSIONS: Measurements were more repeatable when no periapical lesion was present. Root ZX showed better repeatability than RomiApex. CLINICAL RELEVANCE: Periapical lesions seem to influence successive in vivo measurements with EALs.

Panoramic Dental Radiography Image Enhancement Using Multiscale Mathematical Morphology.

Panoramic dental radiography is one of the most used images of the different dental specialties. This radiography provides information about the anatomical structures of the teeth. The correct evaluation of these radiographs is associated with a good quality of the image obtained. In this study, 598 patients were consecutively selected to undergo dental panoramic radiography at the Department of Radiology of the Faculty of Dentistry, Universidad Nacional de Asunción. Contrast enhancement techniques are used to enhance the visual quality of panoramic dental radiographs. Specifically, this article presents a new algorithm for contrast, detail and edge enhancement of panoramic dental radiographs. The proposed algorithm is called Multi-Scale Top-Hat transform powered by Geodesic Reconstruction for panoramic dental radiography enhancement (MSTHGR). This algorithm is based on multi-scale mathematical morphology techniques. The proposal extracts multiple features of brightness and darkness, through the reconstruction of the marker (obtained by the Top-Hat transformation by reconstruction) starting from the mask (obtained by the classic Top-Hat transformation). The maximum characteristics of brightness and darkness are added to the dental panoramic radiography. In this way, the contrast, details and edges of the panoramic radiographs of teeth are improved. For the tests, MSTHGR was compared with the following algorithms: Geodesic Reconstruction Multiscale Morphology Contrast Enhancement (GRMMCE), Histogram Equalization (HE), Brightness Preserving Bi-Histogram Equalization (BBHE), Dual Sub-Image Histogram Equalization (DSIHE), Minimum Mean Brightness Error Bi-Histogram Equalization (MMBEBHE), Quadri-Histogram Equalization with Limited Contrast (QHELC), Contrast-Limited Adaptive Histogram Equalization (CLAHE) and Gamma Correction (GC). Experimentally, the numerical results show that the MSTHGR obtained the best results with respect to the Contrast Improvement Ratio (CIR), Entropy (E) and Spatial Frequency (SF) metrics. This indicates that the algorithm performs better local enhancements on panoramic radiographs, improving their details and edges.

A comparison between two negative pressure irrigation techniques in simulated immature tooth: an ex vivo study.

OBJECTIVES: This ex vivo study evaluated the irrigation efficacy of a new apical negative pressure system (ANP) in canals with simulated immature teeth, by comparing it to EndoVac (EV) system in terms of smear layer (SL) removal and irrigation extrusion. MATERIALS AND METHODS: Three millimetres of the root end of 40 single canalled lower incisors were resected and decoronated to standardize root canal length. After instrumentation, the specimens were embedded in warm normal saline agar coloured with 1 % acid red and randomly divided into four groups; one control group and three experimental groups. Except in the control group where distilled water was used as irrigant using positive pressure irrigation needle, the canals were irrigated with 6 % NaOCl and 17 % EDTA using the intracanal negative pressure needle (iNP) system, the EV system or 27G open-ended needle under positive pressure (PP). NaOCl extrusion was determined by observing a discolouration of the agar surrounding the root. The SL was evaluated by observing scanning electron microscope images based on a four-level scoring system. RESULTS: Two specimens with irrigant extrusion were observed in the iNP group, which was significantly different (logistic regression, p < 0.05) to EV and PP. There were no significant differences (Kruskall-Wallis test, p > 0.05) among the experimental groups in terms of SL removal, but all were significantly different to the control group. CONCLUSIONS: Irrigation with the iNP could be a viable alternative to EV as an apical negative pressure irrigation technique especially while treating immature teeth. CLINICAL RELEVANCE: ANP in canal cleanliness is recommended to be utilized in treating immature teeth where periapical tissues should be saved and stimulated. The iNP system might have the potential to avoid irrigant extrusion while cleaning the canal till the apical end.

Irrigation effectiveness of continuous ultrasonic irrigation system: An ex vivo study.

This study evaluated the irrigation extrusion and smear layer (SL) removal of continuous ultrasonic irrigation (CUI). Forty root canals were shaped, embedded in warm sterile saline agar colored with 1% acid red, and distributed into four groups; three groups had the final irrigation sequence of sodium hypochlorite and EDTA solutions performed by using syringe irrigation (SI), EndoVac (EV), and CUI, respectively. Group 4 had the canals ultrasonically irrigated with saline (CUIS). Irrigant extrusion was verified by a color change of the agar. The SL was evaluated under scanning electron microscope. Irrigant extrusion was observed in two and four teeth in the CUI and SI, respectively, whilst none had irrigant extruded in the EV. In term of SL, the CUI was comparable to EV at 1 and 3 mm but different to SI at 1 mm. Although CUI might clean the root canal system effectively, it was unable to avoid irrigant extrusion.

Comparison of the Volume of Root Canal Irrigant Collected by 2 Negative Pressure Needles at Different Flow Rates of Delivery.

INTRODUCTION: A greater irrigant volume improves the effectiveness of root canal irrigation. The purpose of this study was to compare 2 negative pressure systems regarding the volume of irrigant collected from the apical area in moderately curved canals at 3 different flow rates of delivery in vitro. METHODS: The mesiobuccal canals of 30 molars with a curvature between 20° and 40° were prepared to size #40.04 taper. A closed system was created. The canals were irrigated at 3, 6, and 12 mL/min for 30 seconds using EndoVac (SybronEndo, Orange, CA) and the INP needle (Mixnus Fine Engineering Co Ltd, Nagano, Japan) (both independent variables). A recovery trap was used to collect the irrigant aspirated by the negative pressure needles. Irrigant volume (dependent variable) was measured in milliliters. Data were analyzed using mixed analysis of variance. RESULTS: There was a statistically significant interaction between the negative pressure system and the irrigant volume collected (P < .0005). The mean irrigant volume collected by the different negative pressure systems was greater for INP at 3 (P < .001), 6 (P < .001), and 12 mL/min (P < .001) flow rate. Both negative pressure needles showed statistically significant differences (P < .001) between mean irrigant volume collected at different flow rates. CONCLUSIONS: A greater volume was collected by increasing the flow rate of irrigant delivery for both EndoVac and INP. The INP needle could collect a greater volume of irrigant from the apical third compared with EndoVac at all 3 different flow rates.

Self-report on COVID-19: a survey of paraguayan dentists / Autorreporte acerca del contagio de COVID-19: una encuesta a odontólogos paraguayos

Aim: To determine the frequency of signs and/or symptoms compatible with COVID-19 in Paraguayan dentists, as well as the possible source of contagion. Material and Methods: Online survey consisting of 13 questions, applied to all dentists in Paraguay from January 20 to February 15, 2021. Results: A total of 433 dentists participated in the survey; 47.5% displayed symptoms compatible with COVID-19 and 13.39% indicated that they had contracted the disease, providing confirmation via a positive test result. Headache, loss of smell, loss of taste, cough, and fatigue were the most prevalent symptoms among COVID-19 positive cases. The main source of contagion was the family nucleus. Only one participant reported having contracted the disease while providing dental care. Conclusion: Almost half of the dentists displayed symptoms compatible with COVID-19. Only 13.39% tested positive for COVID-19. Only one case of contagion was reported to have happened during the provision of dental care.

Frecuencia de la posición, inclinación y grado de dificultad quirúrgica de terceros molares mandibulares en pacientes que acuden a la Facultad de Odontología de la Universidad Nacional de Asunción

RESUMEN La disposición que puede adoptar un tercer molar mandibular resulta en la mayoría de los casos impredecible. Para facilitar el análisis de la posición e inclinación de los terceros molares autores como Pell-Gregory y Winter, establecieron una clasificación de esas piezas dentarias para guiar la técnica operatoria más adecuada para cada situación. El objetivo fue determinar la frecuencia de la posición, inclinación y grado de dificultad quirúrgica en terceros molares mandibulares. El estudio fue observacional descriptivo, retrospectivo de corte transversal. Formaron parte del estudio radiografías panorámicas de pacientes que acudieron a la Facultad de Odontología UNA entre el 2018 y 2020. Un total de 220 radiografías panorámicas fueron incluidas en el estudio, 120 (54,5%) correspondían al sexo femenino y 100 (45,4%) al sexo masculino, la franja etaria de 18 a 28 años fue la de más participación con 134 (61%) radiografías. Se evidenció una frecuencia en la posición A clase II de 141 (36,6%), en cuanto a la inclinación de las piezas dentarias, la más frecuente fue la mesioangular 174 (45,5%) y en cuanto al grado de dificultad quirúrgica se observó una dificultad mínima a moderada. Se evidenció una frecuencia alta de la posición A clase II e inclinación mesial del total de las radiografías analizadas.

ABSTRACT The position a mandibular third molar can adopt is unpredictable in most cases. To facilitate the analysis of the position and inclination of third molars, authors such as Pell-Gregory and Winter established a classification of these teeth to guide the most appropriate surgical technique for each situation. The objective was to determine the frequency of the position, inclination and degree of surgical difficulty in mandibular third molars. The study was descriptive, retrospective, cross-sectional, and observational. Panoramic radiographs of patients who attended the School of Dentistry of the National University of Asuncion between 2018 and 2020 were part of the study. A total of 220 panoramic radiographs were included in the study, 120 (54.5%) corresponded to women and 100 (45.4%) to men, the age group from 18 to 28 years old had the most participation with 134 (61%) radiographs. A frequency in position A class II of 141 (36.6%) was evidenced, while in terms of the inclination the mesioangular was the most frequent, 174 (45.5%) and in terms of the degree of surgical difficulty, minimal to moderate difficulty was observed. A high frequency of position A class II, mesial inclination was evidenced in all the radiographs analyzed.

Cambios en el pH salival de pacientes con ortodoncia fija, tras la aplicación de dos tipos de enjuagues bucales / Changes in salivary pH in patients with fixed orthodontics following the use of two types of mouthwashes

Introducción: Los enjuagues bucales contribuyen a la inhibición de la formación de la placa bacteriana y, por tanto, pueden ayudar a mantener el pH salival cercano a neutro. Objetivo: Identificar cambios en el pH salival de pacientes portadores de aparatología ortodóncica fija, después del enjuague con una solución de Stevia rebaudiana Bertoni y un enjuague comercial de aceites esenciales. Métodos: Se realizó un experimento clínico con un diseño factorial mixto en pacientes portadores de aparatología ortodóncica fija. Una vez firmado el consentimiento informado, treinta y dos pacientes fueron asignados aleatoriamente a uno de 2 grupos: la solución de S. rebaudiana B. al 2 por ciento o un enjuague comercial de aceites esenciales. Se utilizaron 15 ml de enjuague durante 60 s en todos los pacientes. El pH salival fue medido por dos observadores independientes calibrados, utilizando papel medidor de pH antes del enjuague (medición basal) y después del enjuague, a los 5 y 20 min. Los datos fueron analizados mediante el ANOVA mixto. Resultados: Se encontró una interacción estadísticamente significativa entre el tipo de tratamiento y el momento de medición del pH. Los pH medio de los grupos S. rebaudiana y aceites esenciales fueron respectivamente en la medición basal: 6,61 y 6,52 (p = 0,72); a los 5 min: 7,61 y 7,77 (p = 0,40); y a los 20 min: 7,72 y 6,82 (p < 0,001). Conclusiones: Ambos enjuagues tenían el efecto de aumentar el pH salival a niveles alcalinos a los 5 min, pero solo el enjuague de S. rebaudiana B. al 2 por ciento mantuvo el pH básico a los 20 min(AU)

Introduction: Mouthwashes contribute to the inhibition of bacterial plaque formation and, therefore, may help to maintain salivary pH close to neutral. Objective: To identify changes in salivary pH in patients with fixed orthodontics after using a Stevia rebaudiana Bertoni solution and a commercial essential oil mouthwash. Methods: A clinical experiment with a mixed factorial design was carried out in patients with fixed orthodontic appliances. Once informed consent was signed, thirty-two patients were randomly assigned to one of 2 groups: 2 % S. rebaudiana B. solution or a commercial essential oil mouthwash. Fifteen ml of mouthwash was used for 60 s in all patients. Salivary pH was measured by two independent calibrated observers using pH-measuring paper before rinsing (basal measurement) and after rinsing, after 5 and 20 min. The data were analyzed by mixed ANOVA. Results: A statistically significant interaction was found between the type of treatment and the time of pH measurement. The medium pH of the S. rebaudiana and essential oil groups were respectively as per basal measurement: 6.61 and 6.52 (p = 0.72); after 5 min: 7.61 and 7.77 (p = 0.40); and after 20 min: 7.72 and 6.82 (p < 0.001). Conclusions: Both mouthwashes had the effect of increasing salivary pH to alkaline levels after 5 min, but only the 2 percent S. rebaudiana B. mouthwash maintained the basic pH after 20 min(AU)

Effects of 6 Single-File Systems on Dentinal Crack Formation.

INTRODUCTION: The purpose of this study was to compare the formation of microcracks after canal preparation performed with different single-file systems as One Shape (Micro-Mega, Besancon, Cedex, France), F6 SkyTaper (Komet Italia Srl, Milan, Italy), HyFlex EDM (Coltene/Whaledent AG, Altstatten, Switzerland), WaveOne (Dentsply Maillefer, Ballaigues, Switzerland), Reciproc (VDW, Munich, Germany), and WaveOne Gold (Dentsply Maillefer). METHODS: Eighty-four human extracted mandibular central incisors (40-60 y) were selected and divided into 6 experimental groups (n = 12 teeth) and a control group (unprepared teeth): One Shape (group 1), F6 SkyTaper (group 2), HyFlex EDM (group 3), WaveOne (group 4), Reciproc (group 5), and WaveOne Gold (group 6). Roots were then sectioned at 3, 6, and 9 mm from the apex, and the surface was observed under a stereomicroscope. Data were analyzed using logistic regression (P < .05). RESULTS: No cracks were observed in the control group. All the systems tested caused cracks, mainly in the apical section (3 mm). HyFlex EDM (33.3%) and WaveOne Gold (58.3%) showed fewer microcracks than other experimental groups (P < .01); however, no significant difference was found between them in crack formation (P > .05). There was no difference among the other experimental groups (P > .05). CONCLUSIONS: All the instruments tested created dentinal cracks. Within the limitations of this study, the flexibility of nickel-titanium instruments because of heat treatment seems to have a significant influence on dentinal crack formation. HyFlex EDM and WaveOne Gold caused less microcracks than the other instruments tested.

Depresión, ansiedad y estrés durante la pandemia COVID-19 en estudiantes de Odontología / Depression, anxiety and stress during the COVID-19 pandemic in dental students

Resumen Introducción: en diciembre del 2019, se reporta en el mundo un caso de neumonía causada por el coronavirus 2 (SARS-CoV-2). En Paraguay, actualmente se registraron más de 428.000 casos confirmados y más de 13.500 muertes. En ese contexto, la enseñanza ha tenido que convocarse al entorno virtual generando, en todos los niveles, modificaciones reactivas conductuales nacidas desde diversas causas: la dificultad al acceso a elementos informáticos, necesidad en diversos grados de reaprendizaje en un entorno no habitual y sobre todo la incertidumbre. El objetivo del estudio fue determinar los niveles de depresión, ansiedad y estrés durante la pandemia covid-19 en estudiantes de Odontología. Métodos: para este estudio observacional descriptivo de corte transversal se incluyeron estudiantes de grado de la Facultad de Odontología de la Universidad Nacional de Asunción, matriculados al periodo académico 2021. Se utilizó la escala de Depression, Anxiety and Stress (DASS-21) short form. Cada uno de los tres ejes (depresión, ansiedad y estrés) contiene 7 ítems, divididas en subescalas de contenido similar. Las puntuaciones fueron categorizadas en cinco grupos ordenados (normal, leve, moderada, severa y muy severa). Resultados: los estudiantes de Odontología presentaron cuadros de depresión y ansiedad, con síntomas de ansiedad moderada en un 42,58%; 1,29% presentó depresión severa. Conclusión: la mayoría de los estudiantes de Odontología presentaron cuadros de depresión y ansiedad con síntomas muy comunes, como la imposibilidad de relajarse, falta de iniciativa, irritabilidad y nervios.

Abstract Introduction: in December 2019, a case of pneumonia caused by coronavirus 2 (SARS-CoV-2) was reported in the world. Currently, Paraguay has registered more than 428,000 confirmed cases and more than 13,500 deaths. In this context, teaching has had to be transferred to the virtual environment, generating reactive behavioral modifications at all levels arising from various causes: difficulty in accessing computer elements, the need in varying degrees of relearning in an unusual environment and, above all, uncertainty. The aim of this study was to determine the levels of depression, anxiety and stress during the covid-19 pandemic in dental students. Methods: for this cross-sectional descriptive observational study, undergraduate students from the School of Dentistry of the National University of Asunción, enrolled in the academic period 2021, were included. The Depression, Anxiety and Stress (DASS-21) short form scale was used. Each of the three axes (depression, anxiety, and stress) contains 7 items, divided into subscales of similar content. The scores were categorized into five ordered groups (normal, mild, moderate, severe, and very severe). Results: dentistry students presented symptoms of depression and anxiety with symptoms of moderate anxiety in 42.58%; 1.29% presented severe depression . Conclusion: most of the dental students presented depression and anxiety with very common symptoms such as the inability to relax, lack of initiative, irritability and nervousness.

Effect of nickel titanium file design on the root surface strain and apical microcracks.

The aim of this study was to determine the effect of nickel titanium file design on the root surface strain generated and apical microcracks caused during canal shaping. Thirty-three mandibular incisors were distributed into LightSpeed X, FlexMaster and a control group. A strain gauge was fixed apically on the proximal root surface to determine the maximum strain during canal shaping. Except for the control group, all root canals were enlarged to size 50. Images were taken after removing the apical 1 and 2 mm of the root end. Mean maximum strain values and presence of microcracks were statistically compared using the t-test and chi-square test, respectively. During canal shaping, the strain increased cumulatively with mean maximum strains of 808.2 ± 228.8 and 525.1 ± 168.9 microstrain in LightSpeed X and FlexMaster, respectively (P = 0.004). Both systems caused comparable microcracks. Although LightSpeed X produced higher maximum strain, no difference in microcrack development was found between both systems.

Medidas empleadas por odontólogos paraguayos para disminuir el riesgo biológico en la práctica odontológica durante la pandemia de Covid-19 / Infection control procedures used by Paraguayan dentists to reduce biological risk in dental practice during the Covid-19 pandemic

Resumen Introducción: los profesionales en odontología han sido identificados como de muy alto riesgo de exposición al coronavirus, específicamente cuando llevan a cabo procedimientos de generación de aerosoles en pacientes infecciosos. El objetivo fue conocer los mecanismos mecánicos y químicos usados por los odontólogos paraguayos para evitar la propagación del COVID-19. Evaluar el porcentaje de odontólogos que hayan atendido pacientes COVID positivo y que posteriormente hayan desarrollado la enfermedad. Métodos: estudio observacional descriptivo de corte transversal. Participaron del estudio odontólogos paraguayos con acceso a internet. La difusión del enlace de acceso se realizó por redes sociales. Se recolectaron datos sociodemográficos y medidas de protección utilizadas en el consultorio a fin de disminuir el riesgo biológico. Resultados: participaron 428 odontólogos, 84,11 % fueron mujeres, 38,32 % tenía de 30-39 años. Las medidas de desinfección y cuidados más utilizadas fueron la desinfección del sillón dental (96,7 %), lavado de manos del profesional (93,46 %) y desinfección de superficies con alcohol 70 (88,08 %). El 59,1% utilizaba el peróxido de hidrógeno al 1% como enjuague bucal preoperatorio. La mayoría utilizaba tapabocas KN95 (48,83%), bata de tela tejida (78,04 %), bata desechable (72,20%); uso de gorrito (89,49%) y/o cubre calzado (76,40 %) por parte del paciente, y esterilizan en autoclave sus instrumentales (82,48%). Un profesional relató haberse contagiado en el consultorio odontológico. Conclusión: La mayoría de los odontólogos paraguayos encuestados cumple con los protocolos establecidos por el Ministerio de Salud y organismos internacionales, los cuales aparentan ser efectivos como mecanismos de protección contra el COVID-19 en el ambiente clínico.

Abstract Introduction: dental professionals have been identified as having a very high risk of exposure to coronavirus, specifically when they carry out procedures to generate aerosols in infectious patients. The objective was identifying the mechanical and chemical mechanisms used by Paraguayan dentists to prevent the spread of COVID-19. Evaluate the percentage of dentists who have treated positive COVID patients and who have subsequently developed the disease. Methods: it was a cross-sectional descriptive observational study. Paraguayan dentists with internet access participated. The questions were about sociodemographic data and protection measures used in the office to reduce biological risk. The access link was disseminated through social networks. Results: 428 dentists participated in the study, 84.11 % were women, 38.32 % were 30-39 years old. The most used disinfection and care measures were dental chair disinfection (96.7 %), hand washing (93.46 %) and surface disinfection with alcohol 70 (88.08 %). 59.1% used 1% hydrogen peroxide as a preoperative mouthwash. The majority wore KN95 masks (48.83 %), woven cloth robe (78.04 %), disposable robe (72.20 %); The patient is fitted with a disposable surgeon's cap (89.49 %) and/or shoe covers (76.40 %), and their instruments are sterilized in an autoclave (82.48%). One professional reported having been infected in the dental office. Conclusion: most of the Paraguayan dentists surveyed comply with the protocols established by the Ministry of Health and international organizations, which appear to be effective as protection mechanisms against COVID-19 in the clinical environment.

Sustracción Radiográfica Digital de la Estructura Dentaria Removida Durante el Acceso Endodóntico En Incisivos Mandibulares

RESUMEN: El objetivo de este estudio fue comparar la estructura dentaria removida utilizando dos técnicas de acceso endodóntico diferentes en incisivos mandibulares. Treinta y cinco incisivos mandibulares extraídos fueron pesados individualmente con una balanza de precisión. Después de las radiografías iniciales tomadas por vestibular y proximal, los dientes fueron codificados y asignados aleatoriamente a dos grupos: acceso convencional (n = 17) o acceso incisal (n = 18). Luego se volvieron a pesar los dientes y se repitieron las radiografías. Las radiografías digitales se cargaron a un editor de imágenes (Adobe Photoshop) para la sustracción digital de las imágenes por las incidencias VP y MD. Dos observadores independientes y calibrados realizaron las mediciones de las áreas sustraídas. La concordancia inter-observador fue casi perfecta; coeficiente de correlación intraclase igual a 0,94 y 0,98 para las incidencias MD y VP, respectivamente. La prueba de Mann-Whitney encontró diferencias estadísticamente significativas entre los tipos de acc esos en cuanto a la diferencia mediana de los pesos (p = 0,0073) y el área VL (p = 0.0023). También encontró una diferencia estadísticamente significativa entre los tipos de acceso en cuanto al área MD (Prueba t de Welch, p < 0,001). La diferencia de peso fue menor para el acceso incisal que para el acceso convencional. El acceso incisal removió menos tejido dentario que el acceso convencional.

ABSTRACT: The aim of this study was to compare the area of tooth structure removed during two different endodontic access techniques in lower incisors. Thirty-two extracted lower incisors were weighed individually on a precision scale. After initial digital radiographs were taken from buccal and proximal, the teeth were coded and randomly assigned to two different groups: conventional access and incisal access. Once this stage was completed, each tooth was weighed again and 2 postoperative radiographs was taken again, buccal and proximal. Using an image processing software and digital subtraction technique, 2 independent and calibrated evaluators measured difference in tooth structure after access procedures. Interobserver agreement was almost perfect: intraclass correlation coefficient equal to 0,94 and 0,98 for proximal and buccal incidences, respectively. The Mann-Whitney test found statistically significant differences between the types of accesses in terms of weight difference (p = 0.0073) and area VL (p = 0.0023). Additionally, a statistically significant difference between the types of access in the MD area (Welch's t test, p <0.005) was observed. The difference in weight was less for incisal access than for conventional access with a statistically significant difference, in terms of MD and VL area, incisal access and areas of smaller size than conventional access.

Trastornos temporomandibulares e índice de dientes cariados, perdidos y obturados en personas con discapacidad psicosocial crónica internadas en el Hospital Psiquiátrico de la ciudad de Asunción, 2018 / Temporomandibular disorders and decayed, missing and filled teeth index in people with chronic psychosocial disability admitted to the Psychiatric Hospital of the city of Asunción, 2018

Introducción: Los pacientes con trastornos mentales están sometidos a un mayor número de factores de riesgo de enfermedades bucodentales y temporomandibulares. Ello debido a los efectos secundarios de las medicaciones que consumen, la falta de autocuidado, la dificultad para acceder a atención, la actitud hacia los profesionales sanitarios y también la falta de cooperación en los tratamientos dentales. Objetivo: Determinar la frecuencia de los trastornos temporomandibulares (TTM) y el índice de dientes cariados, perdidos y obturados (CPO-D) en pacientes con discapacidad psicosocial crónica internados en el Hospital Psiquiátrico de la ciudad de Asunción, Paraguay. Material y Métodos: El estudio tuvo un diseño observacional descriptivo de corte transversal y fue aprobado por el comité de ética institucional. Participaron 139 personas con discapacidad psicosocial crónica de ambos sexos, mayores de 18 años, en el mes de mayo, 2018. Como instrumentos de medición se utilizaron: un cuestionario de 3 preguntas, el examen clínico con 5 indicadores para la variable presencia de TTM, el odontograma para el índice CPO-D y los expedientes clínicos. Resultados: Se encontró una población en su mayoría masculina, con un rango de edad entre 40-50 años, y un alto porcentaje de fumadores activos. Se observó que el 83,5 % de los examinados presentaba TTM. El índice CPO-D fue 22,8. Entre los signos de TTM, el ruido articular fue el más común. Conclusión: Se observó una elevada frecuencia de TTM en las personas con discapacidad psicosocial y un elevado índice CPO-D. Palabras Claves: Salud bucal, trastornos ATM, índice CPO, salud mental, psiquiatría, trastorno psicosocial.

Introduction: Patients with mental disorders are subject to a greater number of risk factors for oral and temporomandibular diseases. This is due to the side effects of the medication they consume, the lack of self-care, the difficulty in accessing medical help, the attitude of the patients towards health professionals and also the lack of cooperation in their dental treatments. Objective: To determined the frequency of temporomandibular disorders (TMD) and the decayed, missing and filled teeth index (DMFT) in people with chronic psychosocial disability admitted to the Psychiatric Hospital of the city of Asunción. Material and Methods: This descriptive, observational and cross-sectional study was approved by the local ethics committee. One hundred and thirty-nine people with chronic psychosocial disabilities, of both sexes, over 18 years of age participated during May, 2018. The instruments used were a 3-item questionnaire, clinical examination with 5 indicators for presence of TMD, the odontogram for the DMFT index and the clinical charts. Results:A predominantly male population, with an age range between 40-50 years, and a high percentage of active smokers was found. TMD was found in 83.5% and the DMFT index was 22.8. Among the signs of TMD, joint noise was the most common. Conclusion:A high frequency of TMD was observed in people with psychosocial disabilities and a high CPO-D index. Key words: Oral health TMJ , disorder, DMF index, mental health, psychiatry

Conocimiento y práctica de la normativa de la receta simple archivada para la prescripción de antibióticos de uso sistémico en odontólogos de Asunción y Gran Asunción en el año 2019 / Knowledge and practice of the regulation of the simple archived prescription for systemic use antibiotics in dentists of Asunción and Gran Asunción in 2019

El uso descontrolado de los antibióticos favoreció el desarrollo de resistencia bacteriana que va aumentando considerablemente conforme van pasando los años y se ha convertido en una de las mayores amenazas para la salud pública. Es por ello que el Ministerio de Salud Pública y Bienestar Social (MSPyBS) emitió la Resolución S.G. N° 576/18 en la que se dispone la venta obligatoria de medicamentos que tengan actividad antibiótica de uso sistémico bajo receta simple archivada. El objetivo de este trabajo fue medir el nivel de conocimiento y práctica de la normativa de la receta simple archivada para la prescripción de antibióticos de uso sistémico en odontólogos de Asunción y Gran Asunción. El diseño del estudio fue observacional descriptivo, de corte transversal, en donde participaron 190 profesionales odontólogos. Los resultados obtenidos en este estudio mostraron que el 77,89% de los odontólogos respondió que conoce la Resolución S.G. N° 576/18 del MSPyBS, y 94,21% respondió que sabe qué datos incluir en la receta simple archivada. Sólo 11,28% incluye correctamente todos los datos requeridos. También se pudo observar que la amoxicilina es el antibiótico más recetado por los odontólogos (79,47%). En conclusión, se observó que solo el 40,0% de los profesionales encuestados tuvieron un nivel de conocimiento suficiente, mientras que el 60,52% tuvo un nivel de práctica adecuado

The uncontrolled use of antibiotics favored the development of bacterial resistance that has increased considerably in the last years and has become one of the greatest threats to public health. This is the reason why the Ministry of Public Health and Social Welfare (MSPyBS) issued the Resolution SG No. 576/18, which stipulates the mandatory sale of drugs that have systemic antibiotic activity under a simple archived prescription. The aim of this study was to measure the level of knowledge and practice on the regulation of the simple archived prescription for systemic antibiotics of dentists in Asunción and Gran Asunción. The study design was descriptive, cross-sectional and 190 dentists participated. The results showed that 77.89% of dentists knew about Resolution S.G. No. 576/18 of the MSPyBS, and 94.21% replied that they knew what information to include in the simple archived prescription. Only 11.28% correctly included all the required data. It was also observed that amoxicillin was the most prescribed antibiotic by dentists (79.47%). In conclusion, it was observed that only 40.0% of the professionals surveyed had a sufficient level of knowledge, while 60.52% had an adequate level of practice

Evaluación de la extrusión del agente irrigante de acuerdo a la técnica de irrigación en dientes humanos, ex vivo / Irrigant extrusion according to irrigation technique inhuman teeth, ex vivo

El agente irrigante debería alcanzar la totalidad del conducto radicular, inclusive las zonas más apicales, para mejor la limpieza y desinfección. Sin embargo existe el riesgo de la extrusión del mismo a los tejidos periapicales. El presente estudio con diseño experimental tuvo el objetivo de evaluar la extrusión apical del agente irrigante endodóntico de acuerdo a la técnica de irrigación durante la irrigación final en dientes naturales, ex vivo. Se utilizaron 46 dientes anterosuperiores naturales extraídos con conducto único y las raíces se sumergieron en una gelatina conductora incolora. Una aguja de irrigación/aspiración fue colocada a 2 mm de la longitud de trabajo y se irrigaron los conductos con una solución de contraste a 4 ml/min durante 60 s. En 18 dientes se utilizó la técnica de irrigación por jeringa y en los 18 restantes se utilizó la técnica por presión negativa. Los controles positivos y negativos estaban compuestos por 5 dientes cada uno. Se evaluaron presencia y área de extrusión. La prueba Chi2 encontró una asociación estadísticamente significativa (p <0,001) entre la presencia de extrusión y la técnica de irrigación. El área mediana de extrusión provocada por irrigación por jeringa (0,645 mm2) fue estadísticamente mayor a la provocada por la irrigación por presión negativa (0 mm2) (U Mann Whitney, p <0,001). Se concluyó que la irrigación por presión negativa produce menos extrusión de la solución irrigante, no sólo en frecuencia sino también en área de extrusión comparado con la irrigación por jeringa.

Root canal irrigants should be able reach the entire root canal system, including the mostapical portions, in order to achieve better cleaning and disinfection. However, there exists arisk of irrigant extrusion to the perirradicular area. The present study had an experimentaldesign with the purpose of evaluating irrigant apical extrusion of the endodontic irrigantaccording to the irrigating technique during final irrigation y extracted human teeth, ex vivo.Forty six anterior upper single canaled teeth were used and the roots were embedded into aconducting transparent gel. An irrigating/aspirating needle was placed 2 mm from workinglength and irrigation was performed with a contrast solution at 4 ml/min during 60 s.Eighteen teeth were used for syringe irrigation and negative pressure irrigation each Additionally, 5 teeth were used for positive and negative controls, each. The presence andextrusion area were evaluated. The Chi2 test found a statistically significant asociation (p <0,001) between extrusion and irrigation technique. The median area of extrusion by syringeirrigation (0,645 mm2) was statistically greater than that by negative pressure irrigation (0mm2) (Mann Whitney U, p <0,001). In conclusion, the frequency and extent of extrusioncaused by negative pressure irrigation was less compared to syringe irrigation.

Crack initiation on the apical root surface caused by three different nickel-titanium rotary files at different working lengths.

INTRODUCTION: The aim of this study was to compare the effects of three brands of nickel-titanium (NiTi) rotary files with different designs on the initiation of apical root cracks when working short, at, and beyond the apical foramen. METHODS: One-hundred eight teeth with straight single canals were selected and mounted on resin blocks with simulated periodontal ligaments, and the apex was exposed. The teeth were divided into 9 groups of 12 teeth according to the NiTi rotary file type used (Profile [Dentsply Maillefer, Ballaigues, Switzerland], K3 [SybronEndo, West Collins, CA], and EndoWave [FKG Dentaire, La-Chaux-de-Fonds, Switzerland]) and working length (at CL, 1 mm short of [CL - 1 mm], and 1 mm beyond [CL + 1 mm] the apical foramen). Digital images of the apical surface of every tooth were taken during the apical enlargement sequence at each file change. These images were compared with the baseline image, and the presence of a crack was noted. RESULTS: Significantly less cracks were observed in the CL - 1 mm group than in the CL and CL + 1 mm groups. No significant difference was found between the file types used. CONCLUSIONS: Working 1 mm short of the apical foramen caused less cracks on the apical surface. In addition, more cracks were observed when using larger file sizes. Instrumentation with NiTi rotary files could potentially cause cracks on the apical root surface.

The effect of root preparation technique and instrumentation length on the development of apical root cracks.

The purpose of this study was to compare the effects of root canal preparation techniques and instrumentation length on the development of apical root cracks. Forty extracted mandibular premolars with straight roots were randomly selected and mounted on resin blocks with simulated periodontal ligaments, and the apex was exposed. The teeth were divided into four groups of 10 teeth each for different canal preparation techniques and instrumentation lengths: group A: step-back preparation (SB) with stainless steel files (SF) using root canal length (RCL) to guide instrumentation length; group B: SB using RCL - 1 mm; group C: crown-down preparation (CD) with Profile using RCL; and group D: CD with PF using RCL - 1 mm. Digital images of the instrumentation sequence were compared for each tooth. Statistical analysis revealed a significant effect of instrumentation length (p < 0.05) but no significant effect of preparation technique (p > 0.05) on the development of apical cracks.