Efeito dos sulfatos de condroitina e de glicosamina sobre a progressão da osteoartrite quimicamente induzida na articulação temporomandibular de coelhos

A osteoartrite (OA) é uma doença degenerativa caracterizada por apresentar variados níveis de inflamação, resultando em erosão de cartilagem articular e concomitante osteogênese subcondral reparativa/adaptativa. A perda da função é a conseqüência de alterações anatômicas nos tecidos das articulações com OA. Frente às limitações funcionais e à sintomatologia dolorosa geradas pelo processo inflamatório na OA, os sulfatos de condroitina e de glicosamina (SCG) surgem como opção terapêutica, considerados drogas modificadoras de sintomas, com efeitos positivos em pacientes que os utilizam em longo prazo. Entretanto, tais componentes vêm sendo testados também como substâncias modificadoras de estrutura, os quais poderiam ser capazes de prevenir, retardar, ou reverter alterações morfológicas das estruturas articulares provocadas pela OA. Assim, os estudos têm avaliado sua ação sobre a cartilagem, o tecido ósseo subcondral e sobre os mecanismos inflamatórios da doença. Esta tese avaliou a influência da terapêutica com os SCG sobre as alterações teciduais provocadas pela OA quimicamente induzida em articulação temporomandibular (ATM) de coelhos. O artigo abordou especificamente o efeito dos SCG sobre a cartilagem articular degenerada, bem como sobre o conteúdo total de glicosaminoglicanos (GAG‘s) do disco e da cartilagem. Os resultados encontrados mostram que os derivados sulfatados apresentam resultados positivos sobre a OA. Além disso, este estudo permite considerar os sulfatos de condroitina e de glicosamina como substâncias modificadoras de estrutura (DMOADs), os quais podem ser indicados aos pacientes que apresentam osteoartrite de articulação temporomandibular (OA-ATM).Osteoarthritis (OA) is a degenerative disease characterized by present varied levels of inflammation, resulting in erosion of articular cartilage and concomitant subchondral repair/adaptative ostheogenesis. Loss of function is the consequence of anatomical changes in the tissues of the joints with OA. Facing the functional limitations and the painful symptomatology generated by the inflammatory process in OA, chondroitin and glucosamine sulfates (CGS) appear as a therapeutic option, considered as symptom modifying drugs, with positive effects in patients who use them in the long term. However, such components have also been tested as structural modifying substances, which could be capable of preventing, retarding, or reversing morphological changes in joint structures caused by OA. Thus, studies have evaluated its action on cartilage, subchondral bone tissue and on the inflammatory mechanisms of the disease. This thesis evaluated the influence of therapy with CGS on tissue changes caused by chemically induced OA in temporomandibular joint (OA-TMJ) of rabbits. The article specifically addressed the effect of CGS on degenerated joint cartilage as well as on the total glycosaminoglycan content (GAG) of the disc and cartilage. The results demonstrate that the sulfated derivatives present positive results on OA. In addition, this study allows us to consider CGS as structure modifying substances (DMOADs), which may be indicated for patients with OA-TMJ

Effects of a buried magnetic field on cranial bone reconstruction in rats

The understanding of bone repair phenomena is a fundamental part of dentistry and maxillofacial surgery. Objective The present study aimed to evaluate the influence of buried magnetic field stimulation on bone repair in rat calvaria after reconstruction with autogenous bone grafts, synthetic powdered hydroxyapatite, or allogeneic cartilage grafts, with or without exposure to magnetic stimulation. Material and Methods Ninety male Wistar rats were divided into 18 groups of five animals each. Critical bone defects were created in the rats’ calvaria and immediately reconstructed with autogenous bone, powdered synthetic hydroxyapatite or allogeneic cartilage. Magnetic implants were also placed in half the animals. Rats were euthanized for analysis at 15, 30, and 60 postoperative days. Histomorphometric analyses of the quantity of bone repair were performed at all times. Results These analyses showed significant group by postoperative time interactions (p=0.008). Among the rats subjected to autogenous bone reconstruction, those exposed to magnetic stimulation had higher bone fill percentages than those without magnetic implants. Results also showed that the quality of bone repair remained higher in the former group as compared to the latter at 60 postoperative days. Conclusions After 60 postoperative days, bone repair was greater in the group treated with autogenous bone grafts and exposed to a magnetic field, and bone repair was most pronounced in animals treated with autogenous bone grafts, followed by those treated with powdered synthetic hydroxyapatite and allogeneic cartilage grafts