Immediate laser-induced hemostasis in anticoagulated rats subjected to oral soft tissue surgery: a double-blind study

Abstract Given the growing trend towards medical indications for continuous use of anticoagulants, the number of patients on these medications continues to rise. The management of patients on oral anticoagulants requiring oral surgical procedures has aroused much controversy. Changes in an anticoagulation regimen are associated with an increased risk of thromboembolism. However, it seems logical and advantageous for the patients' health if surgery could be performed without any change to the anticoagulation therapy. In dentistry, high-power lasers have been poorly explored in this field. The hemostatic properties of high-power lasers could be helpful during oral soft tissue surgeries in anticoagulated patients. The aim of this study was to compare bleeding time in anticoagulated rats after lingual frenectomy performed with a scalpel or diode laser with bleeding time in healthy animals. Twenty-four male Wistar rats were assigned to four groups (n = 6): (CS) Control-Scalpel Surgery; (AS) Anticoagulated-Scalpel Surgery; (CL) Control-Laser (diode laser 810 nm/1.5 W) Surgery; and (AL) Anticoagulated-Laser Surgery (diode laser 810 nm/1.5 W). Warfarin administration was used to induce anticoagulation. Blood was blotted every 30 seconds with filter paper until bleeding stopped to verify bleeding time. Two blinded researchers performed the surgeries and collected the bleeding time data. Diode laser surgery led to complete hemostasis in rats during and after lingual frenectomy. Zero bleeding was assessed during surgeries and after diode laser surgeries in anticoagulated rats. Laser-induced hemostasis offered an alternative solution to the controversial issue of intraoperative and postoperative bleeding control in patients on anticoagulation therapy.

Evaluation of Eye Protection Filters Used with Broad-Spectrum and Conventional LED Curing Lights

Abstract The high irradiance and the different emission spectra from contemporary light curing units (LCU) may cause ocular damage. This study evaluated the ability of 15 eye protection filters: 2 glasses, 1 paddle design, and 12 dedicated filters to block out harmful light from a monowave (HP-3M ESPE) and a broad-spectrum (Valo, Ultradent) LED LCU. Using the anterior sensor in the MARC-Patient Simulator (BlueLight Analytics) the irradiance that was delivered through different eye protection filters was measured three times. The LCUs delivered a similar irradiance to the top of the filter. The mean values of the light that passed through the filters as percent of the original irradiance were analyzed using two-way ANOVA followed by Tukey test (a= 0.05). The emission spectra from the LCUs and through the filters were also obtained. Two-way ANOVA showed that the interaction between protective filters and LCUs significantly influenced the amount of light transmitted (p< 0.001). Tukey test showed that the amount of light transmitted through the protective filters when using the HP-3M-ESPE was significantly greater compared to when using the Valo, irrespective of the protective filter tested. When using the HP-3M-ESPE, the Glasses filter allowed significantly more light through, followed by XL 3000, ORTUS, Google Professional, Gnatus filters. The Valo filter was the most effective at blocking out the harmful light. Some protective filters were less effective at blocking the lower wavelengths of light (<420 nm). However, even in the worst scenario, the filters were able to block at least 97% of the irradiance.

Resumo A alta irradiância e diferentes espectros de luz emitidos por aparelhos fotopolimerizadores (Fp) podem causar danos oculares. Este estudo avaliou a capacidade de 15 filtros de proteção ocular em bloquear a luz prejudicial de um Fp convencional (HP-3M ESPE) e outro de largo espectro (Valo, Ultradent). Utilizando sensor anterior do equioamento MARC-Patient Simulator (BlueLight Analytics inc.) a irradiância que passou através dos diferentes filtros protetores foi mensuradas três vezes. Os valores médios da irradiância que passaram pelos filtros foram analisados usando Análise de variância fatorial e pelo teste de Tukey (a= 0.05). O espetro emitido dos Fps através dos filtros também foi obtido. A análise de variância mostrou que a interação entre os filtros protetores e Fps influenciou significantemente a quantidade de luz transmitida (p<0,001). O teste de Tukey mostrou que a quantidade que luz transmitida através dos protetores oculares quando usado o HP-3M ESPE foi significantemente maior quando comparado aos valores para o Valo, independentemente do filtro testado. Quando foi utilizado a fonte de luz HP-3M ESPE, o filtro de proteção ocular permitiu significativamente maior passagem de luz, seguido por XL 3000, ORTUS, Google Professional, e pelo filtro Gnatus. O filtro do Valo foi o mais eficiente ao bloquear a luz prejudicial. Alguns filtros foram menos eficazes ao bloquear menores comprimentos de onde (<420 nm). No entanto, mesmo no pior cenário dos resultados deste estudo, os filtros foram capazes de bloquear ao menos 97% da irradiância emitida pelas fontes de luz testadas.

Estudo do processo de reparação óssea em defeitos na calvária de ratos utilizando sinvastatina associada a um polímero de poli (ácido láctico-co-glicólico) / Study of the bone repair process of defects in rat calvaria using loaded polymer poly (lactide-co-glycolic acid) loaded with simvastatin

Devido à sua peculiar estrutura mineralizada, o tecido ósseo ainda representa um dos desafios para os estudos em bioengenharia regenerativa. Nesse sentido, estratégias realizadas envolvendo o sistema de liberação de drogas através de polímeros bioreabsorvíveis apontam resultados promissores. Esse projeto teve como objetivo empregar PLGA [poli (ácido lático-co-glicólico)] carregado com sinvastatina (SIN) em defeitos ósseos críticos criados em osso parietal de ratos. Foi realizado um defeito de 5.0 mm de diâmetro no osso parietal esquerdo, sendo que no grupo controle (C) foi deixado apenas o coágulo sanguíneo. O grupo experimental foi subdividido como segue: no subgrupo (M), uma membrana de PLGA foi colocada recobrindo o defeito ósseo, de modo que as bordas ultrapassaram a borda do defeito. No outro subgrupo (MSI), microesferas de PLGA 50/50 contendo sinvastatina a 2,5% foram depositadas no interior do defeito, sendo posteriormente recobertas pela membrana de PLGA; no grupo (MSS) foram colocadas microesferas de PLGA sem sinvastatina para avaliar o efeito osteocondutor das microesferas. Os animais foram sacrificados em dois períodos 30 e 60 dias após a cirurgia e as calotas removidas e processadas para análise morfológica em microscopia de luz, microscopia eletrônica de transmissão e varredura, imuno-histoquímica para análise da expressão de OPN (osteopontina), BSP (sialoproteína óssea) e OSAD (osteoaderina) e análise imunocitoquímica da distribuição ultra estrutural da proteína OPN. Os resultados observados mostraram que a formação do novo osso iniciou-se pelas margens do defeito e também pela área central em grupos tratados. A análise da regeneração nos defeitos tratados com SIN mostrou uma disposição ordenada das fibrilas colágenas e uma matriz com aspecto de tecido ósseo em fase mais madura. O estudo mostra que a regeneração do tecido pode ser acelerada e que a matriz neorformada é depositada de forma mais organizada pela liberação gradual da SIN...

Due to its unique mineralized structure, bone regeneration is still a challenge. Numerous strategies had been proposed during the past years, drug delivery system using polymeric scaffolds is a promising strategy. The aim of this study was to employ PLGA [poly (lactide-co-glycolic acid)] loaded with simvastatin(SIN) in bone defects created in rat calvaria. Bone defects with 5.0 mm diameter was created in the left side of the calvarias. In Control group (C) their defects were filled only with blood clot. The experimental group was subdivided. In subgroup (M), a PLGA membrane was covered the defect. In the other subgroup (MSI), PLGA microspheres loaded with 2.5% simvastatin filled the defect over the blood clot inside the defect and subsequently covered with PLGA membrane, another group was criated to evaluet the osteoconductor potencial of microesphers without the (SIN), the MSS group. The animals were sacrificed in 30, 60 after surgery, and the calvarias were removed and processed for light and transmission and scanning electron microscopy analyzes, Osteopontin (OPN), Osteoadherin (OSAD), Bone sialoprotein (BSP) imunnolabeling and immunocytochemical analyzes of the ultrastructural distribution of osteopontin in the neoformed bone. The in vivo experiment revealed that the microspheres containing simvastatin significantly enhanced the disposition of collagen fibrils in immature bone and bone formation in the rabbit calvaria critical size defect...