Partial extraction therapies (PET): a review of the literature / Terapias de extração parcial (TEP): uma revisão da literatura

ABSTRACT One of the most common dental procedures is tooth extraction; however, the bone defect resulting from the process is only partially restored, leading to considerable bone loss. To rehabilitate a fully or partially edentulous patient, we must handle these sites with delicate surgical procedures. There is a large literature presenting attempts to overcome the negative effects of a dental extraction, with the aim of reducing tissue volume loss or restoring the alveolar architecture. In this context, Partial Extraction Therapy (PET) represents a subgroup of interventions to prevent bone loss after extraction using the tooth itself to prevent alveolar bone loss. This literature review aims to make a survey of the published articles on PET, with an emphasis on socket shield technique, and to explain the other techniques such as root burial, pontic-shield and proximal socket-shield, their indications and counter indications in order to deepen the knowledge of these techniques. To identify the included or considered studies, we adopted a detailed search strategy for MEDLINE and Cochrane Library focused in the last 31 years, whose language was English, Spanish or Portuguese. This text presents an analysis of current data regarding the alternatives for alveolar preservation and the installation of immediate implants in these areas, presenting the possibility of a different surgical technique. However, due to the immaturity and lack of conclusive scientific evidence regarding the predictability of the procedures, it is considered that the use of the socket shield technique must be done in an extremely cautious way.

RESUMO Um dos procedimentos odontológicos mais comuns é a extração dentária, contudo, , o defeito ósseo decorrente do processo é apenas parcialmente restaurado, levando a uma perda ossea volumétrica consideravel. Para reabilitar um paciente totalmente ou parcialmente desdentado, devemos manusear estes sitios com intervenções cirúrgicas delicadas. Há uma vasta literatura apresentando tentativas de transpor os efeitos negativos de uma extração dentária, com o objetivo de diminuir a perda volumétrica tecidual ou restaurar a arquitetura alveolar. Neste contexto, a Terapia de Extração Parcial (TEP) representa um subgrupo de intervenções para prevenir a perda óssea após exodontia, usando o próprio dente para prevenir a perda óssea alveolar. Essa revisão de literatura tem por objetivo fazer um levantamento dos artigos publicados sobre as TEP, com ênfase na técnica de socket shield, e explanar a cerca das demais técnicas como sepultamento radicular, pontic-shield e proximal socket-shield, suas indicações e contra-indicações, a fim de aprofundar o conhecimento dessas técnicas. Para a identificação dos estudos inclui?dos ou considerados, adotamos a estrate?gia de busca detalhada para os bancos MEDLINE e Biblioteca Cochrane nos u?ltimos 31 anos, cujo idioma fosse o ingle?s, espanhol ou o portugue?s. Este texto, apresenta uma análise de dados atuais a respeito das alternativas para a preservação alveolar e instalação de implantes imediatos nestas áreas, apresentando a possibilidade de uma técnica cirúrgica diferenciada. No entanto, devido a imaturidade e falta de comprovação cientifica contundente a respeito da previsibilidade dos procedimentos, considera-se que o emprego da técnica de socket shield deve ser feito de forma cautelosa.

Effects of nasoalveolar molding and lip adhesion in the treatment of complete cleft lip-alveolus-palate

Introduction: Cleft lip and palate rank third among congenital defects, demanding early intervention for correction. Aim: To describe the results obtained with the use of nasoalveolar molding (NAM) and lip adhesion in patients with complete cleft lip-alveolus-palate, treated in the Maxillofacial Surgery service of the Pediatric Hospital of Matanzas between 2010 and 2020. Methods: An observational, descriptive, prospective research was carried out, in a universe of 16 patients with a diagnosis of complete cleft lip-alveolus-palate, treated in the Maxillofacial Surgery Service of Matanzas pediatric hospital during the period from January 2010 to December 2020, determining reference points to perform linear measurements that represented the study variables, both in patients treated only with nasoalveolar molding and in those in whom the nasoalveolar molding-lip adhesion binomial was used. Results: With the exclusive use of nasoalveolar molding, there was a significant reduction of the palatal cleft in all patients under study, with increase in maxillary and hemi-maxillary transverse dimension, as well as a significant reduction of the alveolar cleft. The total reduction of the alveolar cleft was only achieved by combining lip adhesion with nasoalveolar molding. Conclusion: The nasoalveolar molding-lip adhesion combination constitutes an effective binomial in the treatment of complete cleft lip-alveolus-palate.

Introducción: Las fisuras de labio y paladar ocupan el tercer lugar entre los defectos congénitos, demandando una temprana intervención para su corrección. Objetivo: Describir los resultados del empleo del moldeo nasoalveolar y la adhesión labial en pacientes con fisura labio-alveolo-palatina completa, atendidos en el Servicio de Cirugía Maxilofacial del hospital pediátrico de Matanzas, entre 2010 y 2020. Métodos: Se realizó una investigación observacional, descriptiva, prospectiva, en un universo de 16 pacientes con diagnóstico de fisura labio-alveolo-palatina completa, atendidos en el Servicio de Cirugía Maxilofacial del hospital pediátrico de Matanzas, durante el período comprendido de enero de 2010 a diciembre de 2020, determinándose puntos de referencia para realizar mediciones lineales que representaron las variables de estudio, tanto en pacientes atendidos solo con moldeo nasoalveolar como en los que se empleó el binomio moldeo nasoalveolar-adhesión labial. Resultados: Con el empleo exclusivo del moldeo nasoalveolar, existió una significativa reducción de la hendidura palatina en los pacientes estudiados, con incremento de la dimensión transversal maxilar y hemimaxilar, así como una significativa reducción de la hendidura alveolar. La reducción total de la hendidura alveolar solo se logró al combinar la adhesión labial con el moldeo nasoalveolar. Conclusión: La combinación moldeo nasoalveolar-adhesión labial constituye un binomio efectivo en el tratamiento de la fisura labio-alveolo-palatina completa.

Neo-osteogenesis using an intentionally exposed polypropylene membrane after tooth extraction versus guided bone regeneration technique: a single-blind randomized controlled trial / Neo-osteogénesis utilizando una membrana de polipropileno expuesta intencionalmente después de la extracción del diente versus técnica de regeneración ósea guiada: ensayo clínico aleatorizado ciego / Neo-osteogênese utilizando uma membrana de polipropileno exposta intencionalmente após extração dentária versus técnica de regeneração óssea guiada: ensaio clínico randomizado e cego

Introduction: The intentionally exposed polypropylene (PP) membrane has been proposed for guided bone regeneration (GBR) of the alveo lar bone after extraction; however, there are biological limitations to this proposal. This study aimed to describe the effects of the PP membrane on neo-osteogenesis after tooth extraction, comparing to intentionally ex posed and primary soft tissue coverage techniques. Methodology: This clinical trial followed the TIDieR checklist and guide. Clinical and histo logical parameters of alveolar repair were compared between groups: 1 (control group), without regenerative procedure; 2, GBR; and 3, inten tionally exposed membrane. Results: Group 3 showed slight effect on the quality of new bone, compared to the control group. Although the GBR was underestimated by the early exposure of the membrane, alveo lar repair and newly formed bone were superior to the other groups. Poly propylene membrane intentionally exposed compromised the volume density of the immature and mineralized bone matrix, the osteoblast and osteocyte count, and stimulated the granulation tissue formation and local inflammatory infiltrate. Conclusions: Despite the exposure of the PP membrane in GBR, this technique improved the quality of new bone and alveolar repair compared to the surgical technique of intentional exposure and alveolus only sutured.

RESUMEN Introducción: La membrana de polipropileno (PP) intencionalmente expuesta ha sido propuesta para la regeneración ósea guiada (GBR) del hueso alveolar después de la extracción; sin embargo, existen limitaciones biológicas a esta propuesta. Este estudio tuvo como objetivo describir los efectos de la membrana de PP en la neo-osteogénesis después de la extracción del diente, en comparación con las técnicas de cobertura de tejido blando primarias y expuestas intencionalmente. Metodología: Este ensayo clínico siguió la lista de verificación y la guía TIDieR. Se compararon los parámetros clínicos e histológicos de la reparación alveolar entre los grupos: 1 (grupo control), sin procedimiento regenerativo; 2, GBR; y 3, membrana expuesta intencionalmente. Resultados: el grupo 3 mostró un ligero efecto sobre la calidad del hueso nuevo, en comparación con el grupo de control. Aunque la GBR fue subestimada por la exposición temprana de la membrana, la reparación alveolar y el hueso neoformado fueron superiores a los otros grupos. La membrana de polipropileno expuesta intencionalmente comprometió la densidad de volumen de la matriz ósea inmadura y mineralizada, el recuento de osteoblastos y osteocitos, y estimuló la formación de tejido de granulación y el infiltrado inflamatorio local. Conclusiones: A pesar de la exposición de la membrana de PP en GBR, esta técnica mejoró la calidad del hueso nuevo y la reparación alveolar en comparación con la técnica quirúrgica de exposición intencional y alvéolo solo suturado.

Introdução: A membrana de polipropileno (PP) intencionalmente exposta tem sido proposta para regeneração óssea guiada (ROG) do osso alveolar após exodontia; no entanto, existem limitações biológicas a esta proposta. Este estudo teve como objetivo descrever os efeitos da membrana de PP na neo-osteogênese após a extração dentária, comparando com as técnicas de exposição intencional e cobertura primária de tecidos moles. Metodologia: Este ensaio clínico seguiu a lista de verificação e o guia TIDieR. Parâmetros clínicos e histológicos do reparo alveolar foram comparados entre os grupos: 1 (grupo controle), sem procedimento regenerativo; 2, GBR; e 3, membrana intencionalmente exposta. Resultados: O Grupo 3 apresentou leve efeito na qualidade do novo osso, em comparação com o grupo controle. Embora o GBR tenha sido subestimado pela exposição precoce da membrana, o reparo alveolar e o osso neoformado foram superiores aos outros grupos. A exposição intencional da membrana de polipropileno comprometeu a densidade volumétrica da matriz óssea imatura e mineralizada, a contagem de osteoblastos e osteócitos e estimulou a formação de tecido de granulação e infiltrado inflamatório local. Conclusões: Apesar da exposição da membrana PP na ROG, esta técnica melhorou a qualidade do novo osso e da reparação alveolar em comparação com a técnica cirúrgica de exposição intencional e alvéolo apenas suturado.

Incidencia de osteítis alveolar por exodoncia de terceros molares mandibulares impactados: una revisión sistemática / Incidence of alveolar osteitis due to extraction of impacted mandibular third molars: a systematic review

La extracción de terceros molares mandibulares impactados trae consigo, en muchas oportunidades, complicaciones posoperatorias como la osteítis alveolar o comúnmente llamada alveolitis seca que dificulta la cicatrización del alveolo. En este sentido, el objetivo de la revisión fue determinar la incidencia de la osteítis alveolar por exodoncia de terceros molares mandibulares impactados. Se realizó la búsqueda bibliográfica sin restricción de año ni de idioma en PubMed, Scopus, Science Direct, Lilacs y Scielo, empleando tèrminos estandarizados en Medical Subject Headings (MeSH NLM). La confección de la investigación se realizó siguiendo los lineamientos PRISMA-2020 y para la evaluación de la calidad y sesgo de los artículos se empleó las herramientas de la National Heart Lung and Blood Institute (NHLBI). Se obtuvieron (n=4907) estudios, los cuales se subieron al aplicativo web Rayyan para seleccionarlos siguiendo los criterios de inclusión y exclusión planteados previamente. Tras el análisis crítico se eligieron 2 estudios para su revisión, cuyos datos se extrajeron según los indicadores establecidos por los autores. Se concluye que existe una incidencia baja de osteítis alveolar despuès de la extracción de terceros molares mandibulares impactados, descartándose la relación entre el gènero y el padecimiento de esta complicación. Además se resalta la irrigación con clorhexidina y suero fisiológico como tratamiento para esta afección. (AU)

The extraction of impacted mandibular third molars often brings with it postoperative complications such as alveolar osteitis or commonly called dry socket that makes it difficult for the alveolus to heal. In this sense, the objective of the review was to determine the incidence of alveolar osteitis due to extraction of impacted mandibular third molars. The bibliographic search was carried out without restriction of year or language in PubMed, Scopus, Science Direct, Lilacs and Scielo, using standardized terms in Medical Subject Headings (MeSH NLM). The preparation of the research was carried out following the PRISMA-2020 guidelines and the tools of the National Heart Lung and Blood Institute (NHLBI) were used to evaluate the quality and bias of the articles. Studies (n=4907) were obtained, which were uploaded to the Rayyan web application to select them following the inclusion and exclusion criteria previously stated. After critical analysis, 2 studies were chosen for review, whose data were extracted according to the indicators established by the authors. It is concluded that there is a low incidence of alveolar osteitis after the extraction of impacted mandibular third molars, ruling out the relationship between gender and suffering from this complication. In addition, irrigation with chlorhexidine and physiological serum is highlighted as a treatment for this condition. (AU)

Preservación alveolar con colgajo vs sin colgajo. Revisión bibliográfica / Socket preservation with flap versus flapless. A literature review

Introducción: La extracción dentaria desencadena una serie de cambios di mensionales en la altura y anchura de la cresta alveolar que se traducen en la pérdida de tejidos blandos y duros, afec tando de forma directa a la calidad de vida de los pacientes. Por ello, se han estudiado diferentes técnicas para la pre servación de la cresta alveolar (PCA) tras las extracciones, con el fin de optimizar los resultados funcionales y estéticos de la futura rehabilitación prostodóncica. El objetivo fue evaluar los resultados de la PCA utilizando un enfoque con colgajo en comparación con un enfoque sin colgajo en términos de cambios óseos en anchu ra y altura. Material y Métodos: Se realizó una búsqueda bibliográfica en tres bases de datos The National Library of Medicine (MEDLINE/PubMed), Scielo y Cochrane Library. Se incluyeron ensayos clínicos aleatorizados en humanos que compara ran la PCA con colgajo y sin colgajo, en los que se analizaran pacientes sanos, mayores de edad, sin hábitos nocivos, en los que era necesaria la exodoncia de un diente mandibular o maxilar. Resultados: Se incluyeron 5 ensayos clí nicos de los últimos 15 años en los que se realizó un total de 74 procedimientos quirúrgicos de PCA con colgajo y 77 sin colgajo en 138 pacientes entre 18 y 75 años, cuyo género sólo se describió en 3 estudios. Los cambios óseos en anchu ra al realizar una PCA con colgajo varían entre –4,18 mm y 3 mm, mientras que al realizar una PCA sin colgajo los cambios son entre 1,74 mm y 3,42 mm. Por otro lado, los cambios óseos en altura al realizar una PCA con colgajo varían entre –0,99 mm y 0,8 mm, mientras que al realizar una PCA sin colgajo los cambios son entre 0,3 mm y 1,42 mm (AU)

Introduction: Tooth extraction triggers a series of dimensional changes in the height and width of the alveolar ridge, which result in the loss of soft and hard tissues, directly affecting patients’ quality of life. Therefore, different techniques for the preservation of the alveolar ridge (PCA) after extractions have been studied in order to optimize the functional and esthetic results of future prosthodontic rehabilitation. The aim was to evaluate the results of PCA using a flap approach compared to a flapless approach in terms of bone changes in width and height. Material and Methods: A literature search was performed in three databases The National Library of Medicine (MEDLINE/ PubMed), Scielo and Cochrane Library. Randomized human clinical trials comparing flap and flapless PCA were included in which healthy patients, over the age of majority, without harmful habits, who needed to have a mandibular or maxillary tooth extraction, were analyzed. Results: A total of 5 clinical trials from the last 15 years were included in which a total of 74 flap and 77 flapless PCA surgical procedures were performed in 138 patients between 18 and 75 years of age and whose gender was only described in 3 studies. Bone changes in width when performing a flapless PCA varied between –4.18 mm and 3 mm, while when performing a flapless PCA the changes were between 1.74 mm and 3.42 mm. On the other hand, bone changes in height when performing a PCA with flap vary between –0.99 mm and 0.8 mm, while when performing a PCA without flap the changes are between 0.3 mm and 1.42 mm (AU)

La alveolitis y sus factores de riesgo en la población adulta joven / Dry socket and its risk factors in a young adult population

Introducción: La alveolitis es la complicación más frecuente de la extracción dental, y constituye la causa más común de las consultas de Urgencias, pues los pacientes presentan dolor en el período postoperatorio. Aunque la etiología de esta afección no es muy conocida, se considera que es un trastorno multifactorial. Objetivos: Determinar el tipo de alveolitis más frecuente en la muestra objeto de estudio, así como establecer la relación entre los factores de riesgo y el tipo de alveolitis. Métodos: Se realizó un estudio descriptivo y trasversal en el Servicio de Urgencias de la Clínica Estomatológica «Celia Sánchez Manduley», de Santa Clara, Villa Clara, desde febrero de 2020 a junio de 2021. El estudio se realizó en un total de 51 pacientes diagnosticados con alveolitis dental. Se estudiaron las siguientes variables: tipo de alveolitis y factores de riesgo (edad, sexo, antecedentes de enfermedades, el uso de tabletas anticonceptivas, hábitos tóxicos, condiciones del medio bucal, características de la maniobra quirúrgica y cuidados postoperatorios); los datos fueron recogidos en un formulario. Resultados: Predominó la alveolitis seca en las pacientes del sexo femenino. El hábito de fumar y la práctica de una maniobra quirúrgica compleja fueron los factores de riesgo preponderantes. Conclusiones: Existe una relación significativa entre la presencia de alveolitis seca y las pacientes del sexo femenino asociadas a los hábitos tóxicos, el uso de tabletas anticonceptivas, y haber sido sometidas a una maniobra quirúrgica compleja.

Introduction: dry socket is the most frequent complication after a dental extraction and constitutes the most common cause of emergency consultations, since patients have pain in the postoperative period. It is considered to be a multifactorial disorder although the etiology of this condition is not well known. Objectives: to determine the most common type of dry socket in the sample under study, as well as to establish the relationship between risk factors and the type of dry socket. Methods: a descriptive and cross-sectional study was carried out in the emergency department at "Celia Sánchez Manduley" Dental Clinic, in Santa Clara, Villa Clara, from February 2020 to June 2021. The study was carried out in a total of 51 patients who were diagnosed with dry socket. Type of dry socket and risk factors such as age, gender, history of diseases, use of contraceptive tablets, toxic habits, conditions of the oral environment, characteristics of the surgical procedure and postoperative care were the variables studied; the data was collected in a form. Results: dry socket predominated in female patients. Smoking and performing a complex surgical maneuver were the predominant risk factors. Conclusions: there is a significant relationship among the presence of dry socket and female patients associated with toxic habits, the use of contraceptive tablets, and having undergone a complex surgical maneuver.

Ecografía pulmonar en la evaluación del paciente crítico / Lung ultrasound in the evaluation of critically ill patients

Introducción: La ecografía es una técnica de imagen no invasiva que permite explorar diferentes órganos de manera inmediata, constituye un instrumento de alto valor diagnóstico al alcance del profesional de la salud, y es utilizada en todas las especialidades médicas. En los últimos años, la evolución tecnológica ha permitido que los aparatos de ecografía sean más pequeños, portátiles, y con una alta resolución, tal es el caso de la ecografía clínica o ecografía a pie de cama. La ecografía del paciente crítico ha cambiado la práctica médica; específicamente la ecografía pulmonar se debe realizar en todos los pacientes con enfermedad pulmonar aguda. Objetivo: Aportar el conocimiento teórico necesario para promover el uso de la ecografía pulmonar en la evaluación del paciente crítico, y contribuir, mediante su aplicación, a la disminución del riesgo de exposición a las radiografías. Métodos: Se efectuó una revisión de la literatura médica actualizada sobre el papel de la ecografía pulmonar en la evaluación del paciente crítico, en el período de julio a diciembre de 2021. Se utilizaron los siguientes motores de búsqueda: SciELO, Medigraphic y Google Académico. Conclusiones: En el contexto actual, la ecografía pulmonar ha adquirido un papel protagónico, pues su uso facilita una evaluación frecuente y no invasiva del paciente crítico con afección pleuropulmonar. Su aplicación garantiza la disminución del riesgo de exposición a las radiografías.

Introduction: ultrasound is a non-invasive imaging technique that allows us to explore different organs immediately; it constitutes an instrument of high diagnostic value within the reach of health professionals and used in all medical specialties. In recent years, technological evolution has allowed ultrasound devices to be smaller, portable and with high resolution, such is the case of clinical ultrasound or bedside ultrasound. Bedside ultrasound in critically ill patients has changed medical practice; specifically, lung ultrasound should be performed in all patients with acute lung disease. Objective: to provide the necessary theoretical knowledge in order to promote the use of lung ultrasound in the evaluation of critically ill patients, as well as to contribute, through its application, to reduce the risk of exposure to radiographs. Methods: a review of the updated medical literature on the role of lung ultrasound in the evaluation of the critically ill patients was performed from July to December 2021. SciELO, Medigraphic and Google Scholar were the search engines used. Conclusions: lung ultrasound has acquired a leading role in the current context, since its use facilitates a non-invasive and common evaluation of the criticall ill patients with pleuropulmonary disease. Its application guarantees the reduction of the risk of exposure to X-rays.

Estudo in vivo do efeito da ozonioterapia como prevenção e/ou tratamento da osteonecrose dos maxilares induzida por medicamentos / In vivo study of the effect of ozone therapy as a prevention and/or treatment of druginduced osteonecrosis of the jaws

O ozônio tem sido utilizado no processo de reparo ósseo em condições desfavoráveis, como na osteonecrose dos maxilares induzida por medicamentos (OMIM). O objetivo deste trabalho foi avaliar a aplicação de ozonioterapia como prevenção e/ou o tratamento da OMIM. Cento e vinte ratos wistar foram distribuídos entre os grupos tratamentos: eles foram induzidos com Zoledronato e receberam ozonioterapia antes da exodontia (prevenção ­ GOP), após exodontia (tratamento ­ GOT), em ambos momentos (prevenção e tratamento ­ GOPT), um grupo não recebeu ozônio (ZOL), e outro recebeu soro fisiológico ao invés da indução (SAL). Após 14 e 28 dias pós-operatórios foram eutanasiados e as peças submetidas as análises histológicas com eosina e hematoxilina, imunoistoquímica, microtomográfica computadorizada (microCT), confocal a LASER e histomorfométrica. Em 14 dias observamos o início do reparo em GOT, assim como um epitélio presente em SAL e GOT, o mesmo ocorre em 28 dias, e uma intensa imunomarcação de osteocalcina (OC) em GOPT em 14 dias. A microCT demostrou maiores médias de BV/TV em todos grupos quando comparados a ZOL (p< 0,001), ZOL apresentou maior porosidade (p=0,03) e o espaçamento trabecular foi maior no grupo GOT quando comparado ao GOP (p< 0,05). A taxa de aposição mineral (MAR) dos grupos GOP foram maiores (21,46±14,12), seguida do grupo GOT (19,66± 13,23). GOT apresentou a maior média de %NBA (68,322±25,296), quando comparado ao grupo ZOL (p < 0,05), seguido pelo grupo SAL (66,039±28,379) e ZOL (60,856±28,425). Diante dos resultados pode-se observar que a ozonioterapia pode modular o reparo alveolar em animais induzidos com ácido zoledrônico(AU)

Ozone has been used in the bone repair process under unfavorable conditions, such as in druginduced osteonecrosis of the jaws (OMIM). The objective of this work was to evaluate the application of ozone therapy as prevention and/or treatment of OMIM. One hundred and twenty wistar rats were distributed among treatment groups: they were induced with Zoledronate and received ozone therapy before tooth extraction (prevention - GOP), after tooth extraction (treatment - GOT), at both times (prevention and treatment - GOPT), one group I did not receive ozone (ZOL), and another received saline instead of induction (SAL). After 14 and 28 days postoperatively, they were euthanized and the pieces submitted to histological analysis with eosin and hematoxylin, immunohistochemistry, computed microtomography (microCT), confocal LASER and histomorphometric analysis. In 14 days we observed the beginning of repair in GOT, as well as an epithelium present in SAL and GOT, the same occurs in 28 days, with intense immunostaining of osteocalcin (OC) in GOPT in 14 days. The microCT showed higher BV/TV means in all groups when compared to the ZOL (p< 0.001), ZOL showed greater porosity (p=0.03) and the trabecular spacing was greater in the GOT group when compared to the GOP (p< 0 .05). The mineral apposition rate (MAR) of the GOP groups were higher (21,46±14,12), followed by the GOT group (19,66± 13,23). GOT had the highest average of %NBA (68.322±25.296), when compared to the ZOL group (p < 0.05), followed by the SAL group (66.039±28.379) and ZOL (60.856±28.425). In view of the results, it can be observed that ozone therapy can modulate alveolar repair in animals induced with zoledronic acid(AU)

Estudo in vivo do efeito da ozonioterapia como prevenção e/ou tratamento da osteonecrose dos maxilares induzida por medicamentos / In vivo study of the effect of ozone therapy as a prevention and/or treatment of druginduced osteonecrosis of the jaws

O ozônio tem sido utilizado no processo de reparo ósseo em condições desfavoráveis, como na osteonecrose dos maxilares induzida por medicamentos (OMIM). O objetivo deste trabalho foi avaliar a aplicação de ozonioterapia como prevenção e/ou o tratamento da OMIM. Cento e vinte ratos wistar foram distribuídos entre os grupos tratamentos: eles foram induzidos com Zoledronato e receberam ozonioterapia antes da exodontia (prevenção ­ GOP), após exodontia (tratamento ­ GOT), em ambos momentos (prevenção e tratamento ­ GOPT), um grupo não recebeu ozônio (ZOL), e outro recebeu soro fisiológico ao invés da indução (SAL). Após 14 e 28 dias pós-operatórios foram eutanasiados e as peças submetidas as análises histológicas com eosina e hematoxilina, imunoistoquímica, microtomográfica computadorizada (microCT), confocal a LASER e histomorfométrica. Em 14 dias observamos o início do reparo em GOT, assim como um epitélio presente em SAL e GOT, o mesmo ocorre em 28 dias, e uma intensa imunomarcação de osteocalcina (OC) em GOPT em 14 dias. A microCT demostrou maiores médias de BV/TV em todos grupos quando comparados a ZOL (p< 0,05), seguido pelo grupo SAL (66,039±28,379) e ZOL (60,856±28,425). Diante dos resultados pode-se observar que a ozonioterapia pode modular o reparo alveolar em animais induzidos com ácido zoledrônico(AU)

Ozone has been used in the bone repair process under unfavorable conditions, such as in druginduced osteonecrosis of the jaws (OMIM). The objective of this work was to evaluate the application of ozone therapy as prevention and/or treatment of OMIM. One hundred and twenty wistar rats were distributed among treatment groups: they were induced with Zoledronate and received ozone therapy before tooth extraction (prevention - GOP), after tooth extraction (treatment - GOT), at both times (prevention and treatment - GOPT), one group I did not receive ozone (ZOL), and another received saline instead of induction (SAL). After 14 and 28 days postoperatively, they were euthanized and the pieces submitted to histological analysis with eosin and hematoxylin, immunohistochemistry, computed microtomography (microCT), confocal LASER and histomorphometric analysis. In 14 days we observed the beginning of repair in GOT, as well as an epithelium present in SAL and GOT, the same occurs in 28 days, with intense immunostaining of osteocalcin (OC) in GOPT in 14 days. The microCT showed higher BV/TV means in all groups when compared to the ZOL (p< 0.05), followed by the SAL group (66.039±28.379) and ZOL (60.856±28.425). In view of the results, it can be observed that ozone therapy can modulate alveolar repair in animals induced with zoledronic acid(AU)

Physiological response to prone positioning in intubated adults with COVID-19 acute respiratory distress syndrome: a retrospective study.

BACKGROUND: COVID-19 related acute respiratory distress syndrome (ARDS) has specific characteristics compared to ARDS in other populations. Proning is recommended by analogy with other forms of ARDS, but few data are available regarding its physiological effects in this population. This study aimed to assess the effects of proning on oxygenation parameters (PaO2/FiO2 and alveolo-arterial gradient (Aa-gradient)), blood gas analysis, ventilatory ratio (VR), respiratory system compliance (CRS) and estimated dead space fraction (VD/VT HB). We also looked for variables associated with treatment failure. METHODS: Retrospective monocentric study of intubated COVID-19 ARDS patients managed with an early intubation, low to moderate positive end-expiratory pressure and early proning strategy hospitalized from March 6 to April 30 2020. Blood gas analysis, PaO2/FiO2, Aa-gradient, VR, CRS and VD/VT HB were compared before and at the end of each proning session with paired t-tests or Wilcoxon tests (p < 0.05 considered as significant). Proportions were assessed using Fischer exact test or Chi square test. RESULTS: Forty-two patients were included for a total of 191 proning sessions, median duration of 16 (5-36) hours. Considering all sessions, PaO2/FiO2 increased (180 [148-210] vs 107 [90-129] mmHg, p < 0.001) and Aa-gradient decreased (127 [92-176] vs 275 [211-334] mmHg, p < 0.001) with proning. CRS (36.2 [30.0-41.8] vs 32.2 [27.5-40.9] ml/cmH2O, p = 0.003), VR (2.4 [2.0-2.9] vs 2.3 [1.9-2.8], p = 0.028) and VD/VT HB (0.72 [0.67-0.76] vs 0.71 [0.65-0.76], p = 0.022) slightly increased. Considering the first proning session, PaO2/FiO2 increased (186 [165-215] vs 104 [94-126] mmHg, p < 0.001) and Aa-gradient decreased (121 [89-160] vs 276 [238-321] mmHg, p < 0.001), while CRS, VR and VD/VT HB were unchanged. Similar variations were observed during the subsequent proning sessions. Among the patients who experienced treatment failure (defined as ICU death or need for extracorporeal membrane oxygenation), fewer expressed a positive response in terms of oxygenation (defined as increase of more than 20% in PaO2/FiO2) to the first proning (67 vs 97%, p = 0.020). CONCLUSION: Proning in COVID-19 ARDS intubated patients led to an increase in PaO2/FiO2 and a decrease in Aa-gradient if we consider all the sessions together, the first one or the 4 subsequent sessions independently. When considering all sessions, CRS increased and VR and VD/VT HB only slightly increased.

Endothelial TRPV4 channels in lung edema and injury.

The alveolo-capillary barrier is relatively impermeable, and facilitates gas exchange via the large alveolar surface in the lung. Disruption of alveolo-capillary barrier leads to accumulation of edema fluid in lung injury. Studies in animal models of various forms of lung injury provide evidence that TRPV4 channels play a critical role in disruption of the alveolo-capillary barrier and pathogenesis of lung injury. TRPV4 channels from capillary endothelial cells, alveolar epithelial cells, and immune cells have been implicated in the pathogenesis of lung injury. Recent studies in endothelium-specific TRPV4 knockout mice point to a central role for endothelial TRPV4 channels in lung injury. In this chapter, we review the findings on the pathological roles of endothelial TRPV4 channels in different forms of lung injury and future directions for further investigation.

The effect of scaffold hydroxyapatite derived from portunus pelagicus shell on the expression of fibroblast growth factor-2 (fgf-2) and bone morphogenetic proteins-2 (bmp -2) in the extraction sockets of cavia cobaya / El efecto del scaffold de hidroxiapatita derivada de portunus pelagicus sobre la expresión del factor de crecimiento de fibroblastos-2 (FGF-2) y las proteínas morfogenéticas óseas-2 (BMP-2) en los alvéolos dentarios de cavia cobaya

Objetive: To determine the expression of Fibroblast Growth Factor (FGF)-2 and Bone Morphogenetic Protein (BMP)-2 after application of scaffold hydroxyapatite from Rajungan crab shell (Portunus pelagicus) in the tooth extraction socket of Cavia cobaya. Material and Methods: This study used a post-test only control group design with 28 Cavia cobaya separated into two groups, control and treatment group. The left mandibular incisor was extracted, and socket preservation was conducted. A hydroxyapatite graft derived from crab shells was mixed with gelatin and eventually turned into a scaffold, which was afterward put into the extraction socket. After 7 days and 14 days, each group was terminated and examined using immunohistochemical staining to observe the expression of FGF-2 and BMP-2. One-Way Anova and Tukey HSD were used to examine the research data. Results: FGF-2 and BMP-2 expressions were observed higher in the group that received hydroxyapatite scaffold at the post-extraction socket than those in the group that did not receive hydroxyapatite scaffold. Conclusion: The application of a hydroxyapatite scaffold from Rajungan crab shell (Portunus pelagicus) to the tooth extraction socket can increase FGF-2 and BMP-2 expression.

Objetivo: Determinar la expresión del factor de crecimiento de fibroblastos (FGF)-2 y la proteína morfogenética ósea (BMP)-2 después de la aplicación de hidroxiapatita de andamio de caparazón de cangrejo Rajungan (Portunus pelagicus) en el alvéolo de extracción dental de Cavia cobaya. Material y Métodos: Este estudio utilizó un diseño de grupo de control solo posterior a la prueba con 28 Cavia cobaya separados en dos grupos, grupo de control y grupo de tratamiento. Se extrajo el incisivo mandibular izquierdo y se realizó la preservación del alvéolo. Un injerto de hidroxiapatita derivado de caparazones de cangrejo se mezcló con gelatina y se convirtió en un andamio, que luego se colocó en el alvéolo de extracción. Después de 7 días y 14 días, se terminó cada grupo y se examinó mediante tinción inmunohistoquímica para observar la expresión de FGF-2 y BMP-2. Se utilizaron One-Way Anova y Tukey HSD para examinar los datos de la investigación. Resultados: Las expresiones de FGF-2 y BMP-2 se observaron más altas en el grupo que recibió la estructura de hidroxiapatita en el alvéolo posterior a la extracción que en el grupo que no recibió la estructura de hidroxiapatita. Conclusión: La aplicación de un andamio de hidroxiapatita de caparazón de cangrejo Rajungan (Portunus pelagicus) al alvéolo de extracción dental puede aumentar la expresión de FGF-2 y BMP-2.

The validity of Salvadoria persica and Nigella sativa in the treatment of dry socket / La validez de Salvadoria persica y Nigella sativa en el tratamiento de la alveolitis seca

Objectives: To evaluate the effectiveness of a mixture of Salvadoria persica and Nigella sativa in treating dry socket and use as a substitute for alvogyl. Patients and method: 52 randomly selected patients with dry socket confirmed clinically by diagnosis, divided into 2 groups, each group containing 26 patient group A treated by admix, and group B treated by alvogyl, clinical features were recorded on the first, second, and third days after treatment. Results: Visual Analog Scale of pain showed a high score on day one but decreased significantly at 2 and 3 days in both groups. But there were no significant differences in pain scores between the two groups on day 1, day 2, or day 3 separately. The two groups revealed identical mean rank scores of pain during the whole study period. Conclusions: A mixture of Salvadoria persica and Nigella sativa showed a significant analgesic and anti-inflammatory effect in the treatment of dry socket and can be used as a substitute for alvogyl. (AU)

Objetivos: Evaluar la eficacia de una mezcla de Salvadoria persica y Nigella sativa en el tratamiento de la alveolitis seca y su uso como sustituto del alvogyl. Pacientes y método: 52 pacientes seleccionados al azar con alveolitis seca confirmada clínicamente por diagnóstico, divididos en 2 grupos, cada grupo con 26 pacientes del grupo A tratado con admix y del grupo B tratado con alvogyl. Las características clínicas se registraron al primer, segundo y tercer día después del tratamiento. Resultados: La escala analógica visual del dolor mostró una puntuación alta el primer día, pero disminuyó significativamente a los 2 y 3 días en ambos grupos. No hubo diferencias significativas en las puntuaciones de dolor entre los 2 grupos los días 1, 2 y 3 por separado. Los dos grupos revelaron las mismas puntuaciones medias de rango de dolor durante todo el periodo de estudio. Conclusiones: Una mezcla de Salvadoria persica y Nigella sativa mostró un efecto analgésico y antinflamatorio significativo en el tratamiento de la alveolitis seca y puede utilizarse como sustituto del alvogyl. (AU)

Anastomosis between the posterior superior alveolar artery and the infra-orbital artery: a review of current terminology / Anastomosis entre la arteria alveolar superior posterior y la arteria infra-orbital: una revisión de la terminología actual

SUMMARY: The posterior superior alveolar artery (PSAA) and the infra-orbital artery (IOA) present intraosseous and extraosseous rami which form an anastomosis in the lateral wall of the maxillary sinus. This anastomosis is always present, however it has not yet been included in anatomical terminology (AT), and different terms are used in scientific communication to refer to it. The aim of this study was to carry out a review of the different terms used to name this vascular structure. A literature review was carried out on the terms used to name the anastomosis between the PSAA and IOA in imaging studies and human cadavers that assessed the presence/frequency of this anatomical structure. The search was carried out in the Medline, EMBASE and LILACS databases, in Portuguese, Spanish and English, with no date restrictions. Qualitative analysis was applied to the studies selected, analysing the terminology used to refer to the anastomosis between the PSAA and IOA. Of the 2108 original articles found, 60 were selected as potentially relevant and 54 studies were finally included for qualitative analysis. Sixteen terms were found to refer to the anastomosis between the PSAA and IOA, the most frequent being Posterior Superior Alveolar Artery (PSAA), followed by Alveolar Antral Artery (AAA). Many terms are used in the medical literature to designate the anastomosis between the PSAA and IOA, the most frequent being PSAA and AAA. There is a need to unify the terms used to designate this vascular structure, and to incorporate the selected term into anatomical terminology, in order to avoid confusion in scientific communication.

RESUMEN: La arteria alveolar superior posterior (AASP) y la arteria infra-orbital (AIO) tienen ramas intra y extra óseas que forman una anastomosis en la pared lateral del seno maxilar. Esta anastomosis está siempre presente, sin embargo, aún no ha sido incluida en la terminología anatómica (TA), por lo que en la comunicación científica se utilizan diferentes términos para referirse a ella. El objetivo de este estudio fue realizar una revisión sobre los diferentes términos utilizados para nombrar esta estructura vascular. Se realizó una revisión de la literatura sobre los términos utilizados para nombrar la anastomosis entre AASP y AIO en estudios imagenológicos y en cadáveres humanos que evaluaron la presencia/frecuencia de esta estructura anatómica. La búsqueda fue realizada en las bases de datosMedline, EMBASE y LILACS, en los idiomas portugués, español e inglés, sin restricción de fecha. Los estudios seleccionados fueron evaluados de forma cualitativa, analizando la terminología empleada para referirse a la anastomosis entre AASP y AIO. Fueron encontrados 2108 artículos originales, siendo seleccionados 60 artículos potencialmente relevantes y finalmente fueron incluidos 54 estudios para análisis cualitativo. Fueron encontrados 16 términos para referirse a la anastomosis entre AASP y AIO, siendo AASP el más frecuente seguido de arteria alveolo-antral (AAA). Son muchos los términos utilizados en la literatura médica para designar la anastomosis entre AASP y AIO, siendo AASP y AAA los más usados. La unificación de los términos utilizados para designar esta estructura vascular y su incorporación en la Terminología Anatómica contribuiría a evitar equívocos en la comunicación científica.

Pulmonary alveolar capillary dysplasia in infants: A rare and deadly missed diagnosis.

The pulmonary alveolocapillary dysplasia (ACD) with pulmonary vein misalignment (PVM) is a rare condition characterized by a congenital anomaly of the development of the pulmonary parenchyma. We present a case of an 8-month-old infant who died quickly from acute respiratory failure complicating an unknown ACD. We also describe its epidemiological characteristics in infants and we discuss the diagnosis's difficulties. In this case, a pulmonary arterial hypertension was decompensated by an infection. A medico-legal autopsy was performed. As for the Histological examination, it showed the features of ACD/PVM.

Fisiología respiratoria: difusión de gases / Gas diffusion

El principal objetivo del sistema respiratorio es permitir un adecuado aporte de oxígeno y remoción del dióxido de carbono. Para esto, debe ocurrir una adecuada difusión de gases en la membrana alvéolo-capilar, proceso pasivo en el que el oxígeno se mueve hacia el capilar y el dióxido de carbono hacia el alvéolo. La ley de Fick establece los determinantes de la difusión, los que están dados por propiedades de la membrana alvéolo-capilar y de los gases. Las características únicas de la membrana alvéolo-capilar favorecen la difusión de gases, pero es el gradiente de presión parcial de los gases el principal determinante. El oxígeno pasa fácilmente por la membrana alvéolo-capilar y se une rápidamente a la hemoglobina, saturándola, cuando se iguala la presión parcial de oxígeno alveolar y la capilar se detiene la difusión de este gas; por lo que la difusión de oxígeno en reposo está limitada por perfusión. El dióxido de carbono difunde 20 veces más rápido que el oxígeno en la membrana alvéolo-capilar, y aunque su gradiente de presión sea menor, el equilibrio se logra aproximadamente en el mismo tiempo. La difusión del oxígeno es más lenta que la del dióxido de carbono debido a su menor solubilidad. En condiciones patológicas tanto el oxígeno como el dióxido de carbono pueden ser limitados por difusión. Para medir la capacidad de difusión la técnica más utilizada es la capacidad de difusión de monóxido de carbono, ya que este gas solo está limitado por difusión.

The main objective of the respiratory system is allowing an adequate supply of oxygen and the removal of carbon dioxide from the tissues. To achieve this, an adequate diffusion of gases must occur in the alveolus-capillary membrane, which is a passive process in which oxygen moves towards the capillary and carbon dioxide towards the alveolus. Fick's law establishes the determinants of diffusion, which are given by properties of the alveolar-capillary membrane and properties of gases. The unique characteristics of the capillary-alveolar membrane favor the diffusion of gases, but it is the partial pressure gradient of the gases the main determinant. Oxygen passes easily through the alveolar-capillary membrane and rapidly binds to hemoglobin, saturating it. When the partial pressure of alveolar oxygen is matched, the diffusion of this gas stops; therefore, the diffusion of oxygen is limited by perfusion. Carbon dioxide diffuses 20 times faster than oxygen in the capillary-alveolar membrane, and although its pressure gradient is less than oxygen, equilibrium is achieved in approximately the same time. The diffusion of oxygen is slower than that of carbon dioxide due to its lower solubility. Under pathological conditions both oxygen and carbon dioxide can be diffusion-limited. To measure the diffusion capacity, the most used technique is the carbon monoxide diffusion capacity, since this gas is only limited by diffusion.

Cone-beam computed tomographic evaluation of dimensional hard tissue changes following alveolar ridge preservation with leucocyte and platelet-rich fibrin techniques: a pilot study / Avaliação tomográfica computadorizada de feixe cônico das alterações dimensionais de tecido duro após preservação de crista alveolar com técnicas de fibrina rica em leucócitos e plaquetas: um estudo piloto

Objective: This study evaluated the effect of leucocyte and platelet-rich fibrin (L-PRF) techniques used in alveolar ridge preservation on dimensional hard tissue changes of the alveolar ridge assessed using cone-beam computed tomography (CBCT) scans. Material and Methods: Elective alveolar ridge preservation surgeries were performed on seven systemically healthy patients who underwent single posterior tooth extraction. Patients were randomly treated with PRF mixed with a commercial bone xenograft (n = 3) or PRF plug (n = 4). CBCT scans were taken immediately after tooth extraction and then four months later, just before implant surgery. Dimensional alterations in socket height (SH), socket area (SA) and socket volume (SV) were evaluated on CBCT scans by percentage differences before and after treatments. Results: Sockets treated with PRF plus bone xenograft had a tendency to maintain alveolar bone dimensions over time (SH= 11.22% to 82.74%, SA= 1.84% to 48.91% and SV= 9.11% to 203.62%), while sockets treated only with PRF plug technique presented only a modest increase in height (SH= 1.47% to 11.11%) but greater alveolar ridge resorption confirmed by a decrease in socket area and volume dimensions (SA= 0.21% to -24.09% SV= 8.53% to -54.12%). Conclusion: Within the limitations of this study, the maintenance of alveolar socket dimensions was observed when PRF was associated with a xenograft. However, the loss of alveolar ridge dimensions was not entirely prevented by PRF treatment alone.(AU)

Objetivo: Este estudo avaliou o efeito das técnicas de fibrina rica em leucócitos e plaquetas (L-PRF) usadas na preservação da crista alveolar em alterações dimensionais de tecido duro da crista alveolar avaliadas por tomografia computadorizada de feixe cônico (CBCT). Material e Métodos: Foram realizadas cirurgias eletivas de preservação da crista alveolar em sete pacientes sistemicamente saudáveis que foram submetidos a uma única extração dentária posterior. Os doentes foram tratados aleatoriamente com PRF misturado com um xenoenxerto ósseo comercial (n = 3) ou com PRF plug (n = 4). CBCT foi realizada imediatamente após a extração dentária e quatro meses depois, imediatamente antes da cirurgia de implante. Alterações dimensionais na altura do alvéolo (SH), área do alvéolo (SA) e volume do alvéolo (SV) foram avaliadas em exames CBCT por diferenças percentuais antes e depois dos tratamentos. Resultados: Os alvéolos tratados com PRF mais xenoenxerto ósseo apresentaram tendência a manter as dimensões ósseas alveolares ao longo do tempo (SH= 11.22% a 82.74%, SA= 1.84% a 48.91% e SV= 9.11% a 203.62%), enquanto alvéolos tratados apenas com a técnica de PRF plug apresentaram apenas um aumento modesto na altura (SH= 1.47% a 11.11%), mas uma maior reabsorção alveolar confirmada pela redução das dimensões de área e volume do alvéolo (SA= 0.21% a -24.09% SV= 8.53% a -54.12%). Conclusão: Dentro das limitações deste estudo, a manutenção das dimensões alveolares foi observada quando o PRF foi associado ao xenoenxerto. No entanto, a perda das dimensões alveolares não foi totalmente evitada pelo tratamento apenas com PRF. (AU)

Uso de membrana de colágeno y placa de protección mecánica como instrumento de conservación alveolar / Use of collagen membrane and mechanical protective plate as an instrument for alveolar preservation

Luego de una extracción dental ocurren inevitablemente procesos de reabsorción y remodelación ósea, donde la dimensión y morfología de la cresta alveolar se ve modificada, representando un problema para la rehabilitación de la zona. Estudios clínicos han documentado un promedio de 4,0 a 4,5 mm de reabsorción ósea horizontal luego de una exodoncia, como así también cambios dimensionales significativos en los alrededores del hueso alveolar. El propósito fue evaluar y comparar clínica y tomográficamente los procesos de reparación y conservación del reborde alveolar post-extracción de paredes intactas, con y sin la utilización de esponjas de colágeno intraalveolar como relleno y placa termoformada como barrera física, durante el proceso de cicatrización. Se seleccionaron pacientes con indicación de exodoncia de elementos dentarios normalmente implantados y clínicamente aceptables, aplicando los criterios de exclusión, se realiza toma de impresión del terreno para la confección de una placa de protección rígida 0,8 termoformada para ser colocada posterior a la extracción durante la masticación por un período de 30 días. Se indica tomografía cone-beam post operatoria inmediata y a los tres meses para analizar, medir y comparar alto y ancho de crestas alveolares residuales. En la evaluación clínica y tomográfica de los casos estudiados, el grupo control donde se usó únicamente placa de protección alveolar arrojó mejores resultados que el grupo donde se colocaron esponja de colágeno en el interior del alvéolo. Palabras clave: Regeneración ósea, esponja de colágeno, cicatrización ósea, alvéolo postextracción, placa de protección alveolar (AU)

After a tooth extraction, bone resorption and remodeling processes inevitably occurs, where size and morphology of the alveolar crest is modified, representing a problem for the rehabilitation of the area. Clinical studies have documented an average of 4.0 to 4.5 mm of horizontal bone resorption after an extraction, us well us substantial dimensional changes around the alveolar bone. The purpose was to evaluate and compare clinical and tomographically both repair and preservation of post extraction alveolar ridge of intact walls processes, with and without the use of intraalveolar collagen sponges as filler and a thermoformed protective plaque, us physica? barrier, during healing process. Patients with normally implanted and clinically acceptable tooth with extraction indication were selected, applying the exclusion criteria, impression of the field is taken to build a 0.8 rigid thermoformed protective plaque in order to be placed after extraction and used during chewing for a period of 30 days. Immediate and three months post-operative cone beam tomography are indicated to analyze, measure and compare height and width of residual alveolar crests. In the clinical and tomographic evaluation of the cases treated, control group where only alveolar protective plaque was used, showed better results than the group with intraalveolar collagen sponge (AU)

Hexavalent chromium exposure alters bone remodeling in the developing tooth alveolus and delays tooth eruption / La exposición a cromo hexavalente altera la remodelación ósea del alvéolo dental en desarrollo y retarda la erupción dentaria

ABSTRACT Although it has been demonstrated that exposure of lactating rats to CrVI delays tooth eruption, the effects of CrVI exposure on bone remodeling in the developing alveolus during tooth eruption remain unknown. Our purpose was to analyze the effect of CrVI in the alveolus of the first lower molar of rats. Thirty-two suckling Wistar rats were divided into two groups. The experimental group received 12.5 mg/kg body weight/day of potassium dichromate dissolved in saline solution by oral gavage as of day 4 of the experiment; the control group received an equal dose of saline solution. Each group was divided into two sub-sets and euthanized at the ages of 9 and 15 days, respectively. Histochemical and histomorphometric studies of the bone surfaces of the developing tooth alveolus were performed. The percentage of bone formation surfaces was lower in experimental animals than in age-matched controls. The percentage of bone resorption surfaces was significantly lower in 9-day-old experimental rats than in controls and significantly higher in 15-day-old experimental rats than in controls. Exposure to CrVI during lactation alters the sequence of bone resorption and formation in the walls of the developing alveolus, both of which are necessary for tooth eruption, thus causing a delay.

RESUMEN Si bien ya ha sido demostrado que la exposición a CrVI de ratas lactantes retrasa la erupción dentaria, aún se desconocen los efectos de la exposición a CrVI que se producen sobre la modelación y remodelación de las paredes del alvéolo en formación que ocurren en los diferentes estadios de la erupción dentaria. Por tal motivo, el propósito de este trabajo fue estudiar el efecto del CrVI sobre la formación y la reabsorción óseas del alvéolo del primer molar inferior en desarrollo en ratas, a los 9 y a los 15 días de edad, que corresponden a los estadios intraóseo y de penetración mucosa de la erupción dentaria, respectivamente. El grupo experimental recibió una dosis diaria de 12,5 mg/kg de peso corporal de dicromato de potasio disuelto en solución salina por sonda bucal a partir del 4° día; mientras que el grupo control, un volumen equivalente de solución salina. Cada grupo fue dividido en 2 subgrupos de acuerdo al tiempo experimental en el que se llevó a cabo la eutanasia: 9 y 15 días de edad. Se llevaron a cabo estudios histoquímicos e histomorfométricos de las superficies óseas de los alveólos dentarios en formación. Los datos fueron analizados estadísticamente utilizando la prueba t de Student; estableciéndose un valor de p<0,05 como estadísticamente significativo. El porcentaje de superficies en formación fue menor en los animales experimentales de 9 y de 15 días de edad que en los respectivos controles. El porcentaje de superficies en reabsorción en los animales experimentales de 9 días de edad fue significativamente menor y en los animales de 15 días de edad fue significativamente mayor con respecto a sus controles. La exposición al cromo hexavalente durante la lactancia altera la secuencia de la reabsorción y la formación ósea de las paredes del alvéolo en desarrollo necesarias para que la pieza dentaria erupcione, causando su retraso. Los hallazgos obtenidos muestran la importancia del control de sustancias tóxicas en el agua potable, ya que sus efectos pueden alterar la remodelación ósea y por ende, el crecimiento y el desarrollo de los individuos que fueron expuestos durante la infancia temprana.

Ensaio clínico controlado, randomizado e cego, para avaliar a preservação alveolar, utilizando biomaterial de colágeno: resultados preliminares / Controlled, randomized and blind clinical trial to evaluate alveolar preservation using collagen biomaterial: preliminary results

Foi proposito desse trabalho analisar a eficiência na manutenção óssea alveolar após extração dentária pelo biomateral xenógeno (Hemospon®) por meio de imagens tomográficas pré e pósoperatórias de 1 mês e 18 meses de acompanhamento. Trata-se de um estudo clínico controlado, randomizado e cego, onde foram realizadas 18 exodontias, e os alvéolos dentários tratados foram selecionados de forma randomizada e divididos em dois grupos. O grupo 1, grupo teste (G1) foi inserido esponja de colágeno xenógena (porco) e o grupo controle (G2), foi mantido apenas o coágulo sanguíneo local. Os alvéolos foram analisados nos sentidos horizontais e verticais e os resultados foram avaliados através dos testes de Wilcoxon e Mann-Whitney, assumindo uma significância estatística de p<0,05. Além das análises tomográficas os pacientes foram acompanhados diariamente na primeira semana para verificar se os tecidos locais apresentavam possíveis complicações, como a presença de infecção, fistulas e dor persistente. Os resultados iniciais (1 mês) constataram que numa análise em conjunto avaliando altura (p<,0,863), comprimento total (p<1,000) e espessura total do alvéolo (p<0,222), não foram observadas diferenças significativas entre os grupos teste e controle, respectivamente. Na análise de 18 meses, observa-se diferença estatística (p < 0,05) em relação a espessura total do alvéolo, porém em relação ao comprimento total do alvéolo e a altura alveolar não foram observados diferenças estatisticamente significativas (p = 0,36; p = 0,674 ­ respectivamente). Quando de compara-se o G1 em momentos diferentes 1 mês e 18 meses em relação as variáveis observa-se diferenças estatísticas significativas no comprimento total do alvéolo e na espessura (p<0,05), porém não houve signicancia em relação à altura do alvéolo (p=0,575). Analisando em separado cada variável em relação aos grupos G1 e G2 não houve diferença estatística numa análise após 18 meses (p = 0,773 ­ altura alveolar e espessura alveolar; p = 1 ­ comprimento total do alvéolo). Durante o acompanhamento clínico em ambos os grupos não houve diferença no padrão do processo de reparo tecidual, sendo possível reabilitação oral dos pacientes. Mediante os dados preliminares apresentados, a pesquisa demonstrou que os alvéolos tratados com esponja de colágeno porcina (Hemospon®) tiveram perdas ósseas menores, principalmente em relação a espessura, podendo-se inferir que há indícios de uma manutenção alveolar com o uso do biomaterial, podendo ser um biomaterial em potencial e de baixo custo para preservação alveolar, sem aumentar os índices de complicações, porém sugere-se uma análise de uma amostra maior para uma melhor análise estatística (AU).

The purpose of this work was to analyze the efficiency of alveolar bone maintenance after tooth extraction by xenogenous biomaterial (Hemospon®) by means of pre and postoperative tomographic images of 1 month and 18 months of follow-up. This is a controlled, randomized, blinded, clinical study, in which 18 extractions were performed, and the treated dental alveolo were randomly select and devided into two groups. Group 1 test group (G1) a xenogen collagen sponge (pig) was inserted and the control grouop (G2), only the local blood clot was maintained. The alveoli were analyzed in the horizontal and vertical directions and the results were evaluated using the Wilcoxon and Mann ­ Whitney tests assumig a statistical significance of p<0,05. In addition to tomographic analyzes, patients were followed up daily in the first week to check whether local tissues had possible complications such as the presence of infection fistulas and persistent pain. The initial results (1 month) found that in a joint analysis evaluanting height (p<0,863) total length (p<1,00) and total thickness of the socket (p<0,222), no significant differences were observed between the test groups and control respectively. When G1 is compared at different times 1 month and 18 months in relation to the variables there are statistically significant differences in the total length of the alveolus and in the thickness (p<0,05) but there was no significance in relation to the height of the alveolus (p = 0,575). Analyzing each variable separately in relation to groups G1 and G2 there was no statistical difference in an analysis after 18 months (p=0,773 ­ alveolar height and alveolar thickness; p = 1 ­ total alveolar length). During clinical follow-up in both groups there was no difference in the pattern of the tissue repair process with patients oral rehabilitation being possible. Through the preliminary data presented the research demonstrated that the alveoli treated with porcine collagen sponge (Hemospon®) had smaller bone losses mainly in relation to thickness and it can be inferred that there are signs of alveolar maintenance with the use of biomaterial it can be a potential and low-cost biomaterial for alveolar preservation without increasing the complication rates however an analysis of a larger sample is suggested for a better statistical analysis (AU).