Effect of S53P4 bioactive glass and low-level laser therapy on calvarial bone repair in rats submitted to zoledronic acid therapy

ABSTRACT Purpose To evaluate the influence of bioactive glass and photobiomodulation therapy (PBMT) in calvarial bone repair process in rats submitted to zoledronic acid therapy. Methods Twenty-four rats were selected and treated with the dose of 0.035 mg/kg of zoledronic acid every two weeks, totalizing eight weeks, to induce osteonecrosis. After the drug therapy, surgical procedure was performed to create 5-mm diameter parietal bone defects in the calvarial region. The rats were then randomly assigned to groups according to the following treatments: AZC: control group, treated with blood clot; AZBIO: bone defect filled with bioactive glass; AZL: treated with blood clot and submitted to PBMT; and AZBIOL: treated with bioactive glass S53P4 and submitted to PBMT. Tissue samples were collected and submitted to histomorphometric analysis after 14 and 28 days. Results At 14 days, bone neoformation in the AZBIO (52.15 ± 9.77) and AZBIOL (49.77 ± 13.58) groups presented higher values (p ≤ 0.001) compared to the AZC (23.35 ± 10.15) and AZL groups (23.32 ± 8.75). At 28 days, AZBIO (80.24 ± 5.41)still presented significant higher bone recovery values when compared to AZC (59.59 ± 16.92)and AZL (45.25 ± 5.41) groups (p = 0.048). In the 28-day period, the AZBIOL group didn't show statistically significant difference with the other groups (71.79 ± 29.38). Conclusions The bioactive glass is an effective protocol to stimulate bone neoformation in critical defects surgically created in rats with drug induced osteonecrosis, in the studied periods of 14 and 28 days.

Attach great importance to postoperative use of bisphosphonate following osteoporotic fracture / 中华创伤杂志

Osteoporotic fracture is a clinical problem resulting in significant morbidity and mortality. The main treatment for osteoporosis is bisphosphonate therapy. Bisphosphonates can inhibit the bone resorption by osteoclasts, inhibit bone alteration, and maintain bone mass. In recent years, basic and clinical studies have not found evidence that the use of bisphosphonates for the inhibition of fracture healing. Therefore, for the patients with confirmed osteoporotic fracture, bisphosphonate should be used to reduce the risk of re-fracture. The authors summarize the related studies in the bisphosphonate intervention for osteoporotic fracture and recommend postoperative use of bisphosphonate for osteoporotic fracture.

Attach great importance to postoperative use of bisphosphonate following osteoporotic fracture / 中华创伤杂志

Osteoporotic fracture is a clinical problem resulting in significant morbidity and mortality.The main treatment for osteoporosis is bisphosphonate therapy.Bisphosphonates can inhibit the bone resorption by osteoclasts,inhibit bone alteration,and maintain bone mass.In recent years,basic and clinical studies have not found evidence that the use of bisphosphonates for the inhibition of fracture healing.Therefore,for the patients with confirmed osteoporotic fracture,bisphosphonate should be used to reduce the risk of re-fracture.The authors summarize the related studies in the bisphosphonate intervention for osteoporotic fracture and recommend postoperative use of bisphosphonate for osteoporotic fracture.

Treatment of bisphosphonate-related osteonecrosis using platelet-rich plasma: microtomographic, microscopic, and immunohistochemical analyses

Abstract The present study aimed to investigate the use of platelet-rich plasma (PRP) on tooth extraction sites in rats treated with bisphosphonates. Thirty Albinus Wistar male rats were administered 0.035 mg/kg zoledronic acid intravenously for 8 weeks, divided into four administrations with a 2-week interval between each application, after which their upper right central incisors were extracted to induce the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ). The samples were divided into the following two groups: Group 1 (G1) underwent marginal resection of BRONJ followed by the use of PRP, while Group 2 (G2) underwent resection of BRONJ but without the use of PRP. The treatment groups were evaluated after 14, 28, and 42 days. Clinical, microtomographic, microscopic, and immunohistochemical (IHC) evaluations were performed. Microtomography results revealed no significant difference between the groups (p <0.05) in any time period. Histomorphometric analysis showed increased bone formation over time for both groups (p < 0.001). G1 demonstrated a greater amount of new bone formation than G2 at 28 and 42 days (p < 0.001), with G1 presenting greater vascularization and a slightly higher VEGF expression. For both groups, RANKL/OPG expression levels were sufficient as a parameter for indicating the rate of bone remodeling in a previously treated area of osteonecrosis groups. Taken together, our findings indicated that the use of PRP improves the resolution process of BRONJ.

Effects of local alendronate administration on bone defect healing. Histomorphometric and radiological evaluation in a rabbit model

Abstract Purpose: To performed a histomorphometric and radiological study to evaluate the effects of alendronate sodium administered locally in mandibular bone defects created in rabbits. Methods: Two circular defects 5 mm in diameter were created bilaterally in the mandibular corpus of 20 New Zealand rabbits (i.e., four defects per animal). Each defect received one of four treatments: no treatment (EC group), alendronate irrigation (AL group), autogenous bone grafting (AG group), or alendronate irrigation with autogenous bone grafting (AL+AG group). Histomorphometric and radiological assessments were conducted at 4 and 8 weeks after surgery. Results: Between-group comparisons of the new bone area, the value of the AL+AG group was significantly lower thanthe remaining three groups at 4 weeks postoperatively. In all groups, the new bone area was significantly larger at 8 weeks than at 4 weeks. The residual graft area at 4 and 8 weeks was significantly higher in the AL+AG group than in the AG group, although it was significantly smaller at 8 weeks than at 4 weeks in both these groups. Conclusion: The use of alendronate sodium in conjunction with autogenous bone grafting improves the osteoconductive properties of the graft, enhances graft retention in the defect, and improves ossification.

Mecanismos de ação dos bifosfonatos e sua influência no prognóstico do tratamento endodôntico / Bisphosphonates mechanisms of action and its influence in the endodontic treatment prognosis

Os bifosfonatos são medicamentos amplamente utilizados no tratamento de doenças relacionadas à perda de mineral ósseo devido ao aumento da reabsorção óssea, sendo as drogas de primeira escolha no tratamento para osteoporose e demais doenças ósseas crônicas, como doença de Paget ou metástases ósseas osteolíticas. Estes medicamentos atuam, direta ou indiretamente, sobre os osteoclastos e osteoblastos, o que resulta na diminuição da remodelação óssea, além de apresentarem efeitos inibitórios sobre mediadores da inflamação inflamatório, podendo influenciar o processo de reparo de lesões ósseas. Dentro desse contexto, propôs-se a apresentar, por meio de uma revista da literatura, os mecanismos de ação dos bifosfonatos e sua influência no prognóstico do tratamento endodôntico, principalmente no que concerne ao reparo de periodontites apicais. Concluiu-se que os bifosfonatos demonstram, a partir de seus mecanismos de ação, potencial para influenciar no processo de reparo de periodontites apicais, e que mais estudos são necessários a fim de estabelecer uma relação causa-efeito entre o uso de bifosfonatos e o processo de reparo de lesões ósseas.

The bisphosphonates are medicines widely used to treat bone mineral loss related diseases due to increasing of bone resorption, being the first choice drugs for osteoporosis treatment and other chronic bone diseases, as Paget disease or osteolytic bone metastasis. These medicines act, direct or indirectly, on osteoclasts and osteoblasts, which results in bone remodeling decreasing, besides presenting inhibitor effects on the inflammatory modulators, what may influence the bone wounds repair process. Within this context, it is proposed to present, by means of a literature review, bisphosphonates mechanisms of action and its influence on the endodontic treatment prognosis, especially with regard to the apical periodontitis repair process. It was concluded bisphosphonates show potential, from their mechanisms of action, potential to influence in the apical periodontitis repair process, and more studies are required to establish a cause-effect relation between bisphosphonates use and the apical periodontitis repair process.

Osteonecrose associada com o uso dos bifosfonatos / Osteonecrosis associated to the use of bisphosphonates

Introdução: Os bifosfonatos são análogos dos pirofosfatos endógenos e possuem alta afinidade pelos tecidos mineralizados, atuando em sítios de grande formação e reabsorção óssea, sendo utilizados no tratamento da osteoporose, osteogênese imperfeita, displasia fibrosa, doença de Paget, mieloma múltiplo e nas metástases ósseas das complicações de vários tipos de neoplasias malignas. Contudo, numerosas complicações de seu uso vêm sendo descritas, destacando-se o aparecimento de osteonecrose nos ossos gnáticos.Objetivo: Alertar o cirurgião-dentista sobre os possíveis efeitos colaterais dessa classe de drogas sobre o tecido ósseo, os quais podem se assemelhar à outras patologias, como a osteorradionecrose e osteomielites. Verificou-se que a osteonecrose por bifosfonatos é mais comum em pacientes com mieloma múltiplo e câncer de mama, embora também tenha sido relatada em pacientes sob tratamento para osteoporose. Com relação à etiologia, sugere-se uma relação com exodontias e alterações periodontais, embora casos aparentemente espontâneos tenham sido relatados. A despeito da severidade da patologia, não existem protocolos bem estabelecidos de tratamento, variando de conservadores, utilizando a antibioticoterapia e bochechos com clorexidina 0,12%, à radicais, como a mandibulectomia e maxilectomia. Tratamentos alternativos também podem ser realizados, utilizando-se o plasma rico em plaquetas associado às ressecções. Diante dos efeitos dos bifosfonatos aos ossos gnáticos, deve-se dar enfâse à prevenção realizando exames clínicos e radiográficos, a fim de detectar possíveis infecções dentais e realizar os procedimentos convenientes como extrações dentárias, tratamentos endodônticos e periodontais, além de remoção de torus mandibulares ou maxilares, uma das áreas anatômicas mais acometidas.Conclusão: A instituição de protocolos prévios odontológicos a terapia dos bifosfonatos deveria ser uma rotina no início do tratamento médico, promovendo assim à prevenção da osteonecrose.