Membrana de látex natural de Hevea brasiliensis auxilia no processo de reparação tecidual em bovinos / Natural latex rubber from Hevea brasiliensis aids tissue repair of bovine

Feridas cutâneas em bovinos são um constante desafio clínico cirúrgico por desencadearem perdas econômicas bastante significativas. O látex proveniente da seiva da seringueira (Hevea brasiliensis) apresenta potencial terapêutico para incrementar o processo de reparação tecidual. Portanto, pretendeu-se com esse estudo avaliar o tipo de reação tecidual e os possíveis mecanismos de angiogênese desencadeados pelo implante de uma membrana de látex natural em bovinos. Para tal, foram utilizados seis bovinos da raça Nelore, submetidos ao implante subcutâneo experimental de três fragmentos de membranas de látex natural. Foram coletadas amostras de tecido e da membrana aos 15, 30 e 45 dias após a implantação, para avaliações histológicas, ultraestruturais por microscopia eletrônica de varredura e imunoistoquímicas com anticorpos antimarcador de macrófagos (MAC), CYR 61 e VEGF. O implante de látex proporcionou aumento da angiogênese e reparação tecidual em bovinos, não mediada pela expressão do VEGF e CYR 61.(AU)

Cattle wounds are a constant surgical and clinical challenge, leading to important economical losses. The latex from the sap of the rubber tree (Hevea brasiliensis) has therapeutic potential to enhance tissue repair process. Therefore, we evaluated the type of tissue reaction and possible mechanisms of angiogenesis triggered by implanting natural latex rubber in bovine species. Six Nelore bovines were subjected to subcutaneous experimental implant of three fragments of natural rubber latex membranes. Tissue and rubber membrane samples were harvested at 15, 30 and 45 days implantation for histology, scanning electron microscopy and immunohistochemical evaluation with anti macrophage marker (MAC), anti CYR 61, anti VEGF antibodies. The latex membrane estimulates tissue reaction and repair and significant angiogenesis stimuli without activating CYR 61 and VEGF pathways.(AU)

Regeneración ósea guiada en estomatología / Guided bone regeneration in dental practice

Introducción: la regeneración ósea guiada se basa en el concepto de usar una membrana para estabilizar el coágulo sanguíneo y crear un espacio en el que las células procedentes del tejido óseo puedan crecer sin la rápida interferencia de la proliferación de células del tejido blando. Objetivo: realizar una revisión bibliográfica sobre la presencia de la regeneración ósea guiada en revistas de estomatología. Métodos: se realizó una revisión bibliográfica en el periodo comprendido entre julio y agosto de 2014. Se evaluaron revistas de impacto de Web of Sciencies (25 revistas) y 1 cubana. Se consultaron las bases de datos de sistemas referativos MEDLINE, PubMed y SciELO con la utilización de los descriptores: guided bone regeneration, guided tissue regeneration, regenerative medicine dentistry, ridge augmentation, barrier membranes y su equivalente en español. Se incluyó artículos en idioma inglés y español, y publicaciones de los últimos 5 años. Se obtuvó 122 artículos. El estudio se circunscribió a 51 que enfocaron estas temáticas de manera más integral. Análisis e integración de la información: en este tema resulta fundamental el abordaje de principios generales de la regeneración ósea guiada, el papel de las membranas, aplicaciones y complicaciones derivadas de su aplicación clínica. Conclusiones: la regeneración ósea guiada es un tema de publicación frecuente en las revistas estomatológicas. Se refiere a una estrategia de regeneración de tejidos para restaurar hueso. El estudio y desarrollo de membranas de barrera ha ampliado el campo de acción en esta esfera; y ha favorecido su empleo solo o combinado con otros materiales y andamios. En estomatología se pueden emplear en la regeneración periodontal, implantología y trasplante dentario, entre otras aplicaciones. Se describen complicaciones como exposición de la membrana, infección y necrosis(AU)

Introduction: guided bone regeneration is based on the concept of using a membrane to stabilize the blood clot and create a space in which cells from bone tissue may grow without the interference of the quick proliferation of soft tissue cells. Objective: carry out a bibliographic review about the presence of guided bone regeneration in dental journals. Methods: a bibliographic review was performed from July to August 2014. The evaluation included high impact journals from the Web of Sciences (25 journals) and 1 Cuban journal. The databases MEDLINE, PubMed and SciELO were consulted, using the search terms guided bone regeneration, guided tissue regeneration, regenerative medicine dentistry, ridge augmentation, barrier membranes and their Spanish counterparts. The review included papers in English and Spanish, and publications from the last five years. Of the 122 papers obtained, the reviewers selected the 51 which approached the study topics in a more comprehensive manner. Data analysis and integration: within this topic, it is fundamental to approach the general principles of guided bone regeneration, the role of membranes, applications and complications derived from their clinical use. Conclusions: guided bone regeneration is a frequent topic in dental journals. It refers to a tissue regeneration strategy aimed at bone restoration. The study and development of barrier membranes has broadened the scope of this field, allowing its use either by itself or in combination with other materials and scaffolds. Periodontal regeneration, implants and transplants are among the procedures used in dental practice. A description is provided of complications such as membrane exposure, infection and necrosis(AU)

Uso do ácido hialurônico como uma estratégia terapêutica para o reparo ósseo de alvéolos dentais humanos: um ensaio clínico randomizado, triplo-cego, boca dividida / Use of hyaluronic acid as a therapeutic strategy for bone repair in human dental sockets: a split-mouth randomized triple-blind clinical trial

O ácido hialurônico (AH), nas últimas décadas, tem sido amplamente estudado como um potente biomaterial na engenharia de tecidos, devido a sua biocompatibilidade, biodegradabilidade e participação em diversos processos biológicos relacionados à morfogênese e regeneração tecidual. O objetivo do presente estudo foi avaliar os efeitos do AH no reparo ósseo de alvéolos dentais humanos. Trinta e dois primeiros pré-molares inferiores foram extraídos de 16 pacientes com média de 18,67 (DP = 7,95) anos de idade com indicação de exodontia bilateral. Imediatamente após as exodontias, um dos alvéolos foi preenchido aleatoriamente com gel contendo AH a 1%, enquanto o contralateral foi preenchido naturalmente com coágulo. Durante os intervalos pós-operatórios de 30 e 90 dias, os pacientes realizaram exames de tomografia computadorizada cone beam (TCCB). Foram capturadas imagens dos cinco cortes ortorradiais mais centrais de cada alvéolo. A intensidade de cinza foi mensurada para cada imagem e os resultados foram expressos como porcentagem média de formação de osso. A espessura vestíbulo-lingual do processo alveolar foi mensurada e comparada entre os intervalos pós-operatórios para avaliar possíveis alterações dimensionais do alvéolo. Também foi avaliado o padrão do trabeculado ósseo alveolar através da dimensão fractal. A análise estatística envolveu análise descritiva e Testes T pareado e Wilcoxon (p<0,05). Os alvéolos tratados apresentaram maior porcentagem de formação óssea e valores de dimensão fractal (58,17% e 1,098, respectivamente) em comparação com os controles (48,97% e 1,074, respectivamente) no período de 30 dias pós-operatório (p<0,05). Com relação ao período de 90 dias, não foi observada diferença significativa entre os grupos. Além disso, não foram observadas diferenças estatisticamente significativas nas dimensões dos alvéolos entre os grupos (p>0,05). Assim, estes dados indicam que o AH acelerou o reparo ósseo em alvéolos dentais humanos

Hyaluronic Acid (HA), in the last decades, has become widely studied as a powerful biomaterial for tissue engineering, since its biocompatibility, biodegradability, and participation in several biological processes related to morphogenesis and tissue healing. The aim of this study was to evaluate the effects of HA on bone repair in human dental sockets. Thirty-two premolars were extracted from 16 patients with a mean age of 18.67 (SD = 7.95) years old with indication of bilateral extraction of lower first premolars. Immediately after the extractions, one socket was randomly filled with 1% HA gel, while the other side was naturally filled with blood clot. During the postoperative intervals of 30 and 90 days, the patients underwent cone beam computed tomography (CBCT). Five central parasagittal scan images were captured from each socket. The gray intensity was measured in each image and the results were expressed as mean percentage of bone formation. The buccolingual alveolar ridge width was also measured and dimensional changes were compared between the postoperative intervals. The pattern of the alveolar trabecular bone was evaluated through the fractal dimension. Statistical analyses included descriptive analysis and Wilcoxon and paired-t tests (p<0.05). The treated sockets showed a higher percentage of bone formation and fractal dimension values (58.17% and 1.098, respectively) compared with controls (48.97% and 1.074, respectively) in the 30-day postoperative period (p<0.05). After 90 days, there were no significant differences between the groups. Additionally, no significant differences were found between the groups regarding the alveolar dimensions (p>0.05). Thus, these data indicate that HA accelerate the bone repair in human dental socket

[Effect of continuous passive motion for cartilage regenerative surgery - a systematic literature review]. / Wirkung von passiven Motorbewegungsschienen nach knorpelregenerativen Eingriffen - eine systematische Literaturübersicht.

BACKGROUND: The aim of this systematic review was to evaluate treatment effects of continuous passive motion (CPM) after surgical cartilage repair. PATIENTS/MATERIAL AND METHODS: A literature search was conducted in the Cochrane Central Register of Controlled Trials, EMBASE, International Clinical Trials Registry Platform, MEDLINE, Trip Database and in bibliographies of included studies. Two independent researchers evaluated the quality of original investigations by the Cochrane Risk of Bias tool. Systematic reviews were checked by the CBO/Dutch Cochrane Centre Guideline. RESULTS: A total of 1541 studies was initially retrieved from the databases. After screening for inclusion criteria, one review and ten original papers could be included for further evaluation. Studies showed methodological weaknesses. Heterogeneity of outcome measures and the fact that 6 of 9 studies with an one-group pre-post design measured the combined effect of surgical treatment and CPM prevented a meta-analysis. CONCLUSION: Three studies described significant improvements with regard to subjective outcome such as pain, swelling, Quality Life Survey, Knee Society score, WOMAC score or rating Cincinnati due to the surgical treatment and the CPM intervention of cartilage defects in the knee. Six (case) studies suggested an enhanced cartilage quality of the patients after CPM. More high-quality randomised controlled trials are needed to provide high level evidence.

Short-term clinical retrospective study of implants in geriatric patients older than 70 years.

OBJECTIVES: The objectives of this study were to analyze the presence of systemic diseases, associated complications, and other problems occurring after loading of an implanted prosthesis, and to evaluate the amount of bone resorption occurring at the apex of alveolar bone. Therefore, this study analyzed these effects on dental implants in elderly patients with systemic diseases. STUDY DESIGN: In total, 35 patients over the age of 70 years who had been operated on at Seoul National University Bundang Hospital (Seongnam, Korea) between June 2003 and December 2006 were included. According to the types of additional surgical procedures, implant site, implant prosthesis, and systemic diseases, statistical comparisons were made of peri-implant bone resorption at last follow-up. RESULTS: Following the completion of prosthodontic treatment, after a mean period of 32.7 months, the mean peri-implant bone resorption was 0.27 mm, and the peri-implant bone resorption was not significantly related to the type of upper prosthesis (P = .383), the surgical procedures accompanying placement (P = .933), or the presence/absence of systemic disease (P = .484). CONCLUSIONS: According to this analysis, implant therapy in geriatric patients with controlled systemic disease should not be considered to be of particularly high risk.

A retrospective analysis of patients referred for implant placement to a specialty clinic: indications, surgical procedures, and early failures.

PURPOSE: This retrospective study analyzed the pool of patients referred for treatment with dental implants over a 3-year period in a referral specialty clinic. MATERIALS AND METHODS: All patients receiving dental implants between 2002 and 2004 in the Department of Oral Surgery and Stomatology, University of Bern, were included in this retrospective study. Patients were analyzed according to age, gender, indications for implant therapy, location of implants, and type and length of implants placed. A cumulative logistic regression analysis was performed to identify and analyze potential risk factors for complications or failures. RESULTS: A total of 1,206 patients received 1,817 dental implants. The group comprised 573 men and 633 women with a mean age of 55.2 years. Almost 60% of patients were age 50 or older. The most frequent indication for implant therapy was single-tooth replacement in the maxilla (522 implants or 28.7%). A total of 726 implants (40%) were inserted in the esthetically demanding region of the anterior maxilla. For 939 implants (51.7%), additional bone-augmentation procedures were required. Of these, ridge augmentation with guided bone regeneration was performed more frequently than sinus grafting. Thirteen complications leading to early failures were recorded, resulting in an early failure rate of 0.7%. The regression analysis failed to identify statistically significant failure etiologies for the variables assessed. CONCLUSIONS: From this study it can be concluded that patients referred to a specialty clinic for implant placement were more likely to be partially edentulous and over 50 years old. Single-tooth replacement was the most frequent indication (> 50%). Similarly, additional bone augmentation was indicated in more than 50% of cases. Adhering to strict patient selection criteria and a standardized surgical protocol, an early failure rate of 0.7% was experienced in this study population.

A multilevel modelling solution to mathematical coupling.

Owing to mathematical coupling, statistical analyses relating change to baseline values using correlation or regression are erroneous, where the statistical procedure of testing the null hypothesis becomes invalid. Alternatives, such as Oldham's method and the variance ratio test, have been advocated, although these are limited in the presence of measurement errors with non-constant variance. Furthermore, such methods prohibit the consideration of additional covariates (e.g., treatment group within trials) or confounders (e.g., age and gender). This study illustrates the more sophisticated approach of multilevel modelling (MLM) which overcomes these limitations and provides a comprehensive solution to the analysis of change with respect to baseline values. Although mathematical coupling is widespread throughout applied research, one particular area where several studies have suggested a strong relationship between baseline disease severity and treatment effect is guided tissue regeneration (GTR) within dental research. For illustration, we use GTR studies where the original data were found to be available in the literature for reanalysis. We contrast the results from an MLM approach and Oldham's method with the standard (incorrect) approach that suffers from mathematical coupling. MLM provides a robust solution when relating change to baseline and is capable of simultaneously dealing with complex error structures and additional covariates and/or potential confounders.

Collinearity in linear regression is a serious problem in oral health research.

The aim of this article is to encourage good practice in the statistical analysis of dental research data. Our objective is to highlight the statistical problems of collinearity and multicollinearity. These are among the most common statistical pitfalls in oral health research when exploring the relationship between clinical variables using multiple regression analysis. We hope that this article will show why these problems arise and how they can be avoided and overcome. Examples from the periodontal literature will be used to illustrate how collinearity and multicollinearity can seriously distort the model development process as a result of the phenomenon of mathematical coupling. Knowledge of these problems can help to eliminate misleading results and improve any subsequent interpretations. Regression analyses are useful tools in oral health research when their limitations are recognized. However, care is required in planning and it is worthwhile seeking statistical advice when formulating the study's research questions.

Regeneración ósea tras la extirpación de quistes radiculares con y sin regeneración guiada / Bone regeneration after extirpation of radicular cysts with and without guided regeneration

Con el propósito de determinar el grado de regeneración ósea en quistes odontogenicos usando tecnicas de Regeneración Osea Guiada (ROG), hemos realizado un estudio clínico randomizado, controlado y prospectivo. Treinta pacientes con quistes radiculares fueron divididos en tres grupos. El grupo 1 o grupo control (n=10 pacientes) fue tratado con quistectomía de Parstch II y cierre primario. Los otros dos grupos fueron tratados con quistectomía de Parstch II y ROG, usando una membrana reabsorbible (n=10) y membrana no-reabsorbible (n=10). Las membranas se fijaron mediante tornillos no reabsorbibles Memfix System. El volumen residual y la densidad de los tejidos neoformados se evaluaron mediante Tomografia Axial Computarizada (TAC) y mediante analisis de Imagen Digitalizada y Asistida por Computadora (CADIA) antes de la enucleacion y a los 3 y 6 meses de la intervencion. Al realizar el analisis estadistico intergrupos, no se encontro diferencia estadisticamente significativa a los 6 meses respecto al volumen y densidad residual. Estos resultados sugieren que la ROG usando membranas no contribuye a incrementar la regeneración ósea.