Mineral Nanomedicine to Enhance the Efficacy of Adjuvant Radiotherapy for Treating Osteosarcoma.

It is vital to remove residual tumor cells after resection to avoid the recurrence and metastasis of osteosarcoma. In this study, a mineral nanomedicine, europium-doped calcium fluoride (CaF2:Eu) nanoparticles (NPs), is developed to enhance the efficacy of adjuvant radiotherapy (i.e., surgical resection followed by radiotherapy) for tumor cell growth and metastasis of osteosarcoma. In vitro studies show that CaF2:Eu NPs (200 µg/mL) exert osteosarcoma cell (143B)-selective toxicity and migration-inhibiting effects at a Eu dopant amount of 2.95 atomic weight percentage. These effects are further enhanced under X-ray irradiation (6 MeV, 4 Gy). Furthermore, in vivo tests show that intraosseous injection of CaF2:Eu NPs and X-ray irradiation have satisfactory therapeutic efficacy in controlling primary tumor size and inhibiting primary tumor metastasis. Overall, our results suggest that CaF2:Eu NPs with their osteosarcoma cell (143B)-selective toxicity and migration-inhibiting effects combined with radiotherapy might be nanomedicines for treating osteosarcoma after tumor resection.

Comparative Effect of Calcium Mesoporous Silica Versus Calcium and/or Fluoride Products on the Reduction of Erosive Tooth Wear and Abrasive Enamel Lesion

Abstract Objective: To evaluate the effect of a calcium nanocompound on the reduction of erosive tooth wear and abrasion. Material and Methods: Bovine enamel specimens (BE), were randomly assigned to the following groups (n = 10): G1 = Calcium mesoporous silica nanoparticles (Ca2+MSNs); G2 = casein phosphopeptide-amorphous calcium phosphate (CPP-ACP, 2% CPP-ACP, GC®); G3 = casein phosphopeptide-amorphous calcium fluoride phosphate (CPP-ACFP, 2% CPP-ACP + 900 ppm F-, GC®); G4 = sodium fluoride NaF (900 ppm F-, positive control); and G5 = distilled and deionized water (negative control). Each product was applied to the exposed area for one minute, three times per day for three consecutive days, and followed by the immersion of the specimens in Sprite Zero™ - a low-pH solution (2.58) for five minutes (Coca-Cola™). After the first and last erosive challenges of the day, the specimens were submitted to abrasion in a toothbrush machine for 15 seconds (200 g/BE). The specimens were analysed using 3D non-contact optical profilometry, with tooth structure loss (TSL) measurements and scanning electron microscopy (SEM). TSL values were analysed by Kruskal-Wallis and Mann-Whitney tests (p<0.05). Results: There were no significant differences between G1 (10.95 µm) and G3 (10.80 µm) treatments for TSL values; however both resulted in significantly reduced TSL values compared with the G5 (16.00 µm) (p<0.05). The G4 (12.26 µm) showed no statistically significant difference when compared to the G5 (16.00 µm). The groups G1 and G3 presented higher surface preservation than the G5. Conclusion: Ca2+MSNs was effective for reducing tooth surface loss caused by erosive tooth wear and abrasion.

Calcium-based biomaterials for diagnosis, treatment, and theranostics.

Calcium-based (CaXs) biomaterials including calcium phosphates, calcium carbonates, calcium silicate and calcium fluoride have been widely utilized in the biomedical field owing to their excellent biocompatibility and biodegradability. In recent years, CaXs biomaterials have been strategically integrated with imaging contrast agents and therapeutic agents for various molecular imaging modalities including fluorescence imaging, magnetic resonance imaging, ultrasound imaging or multimodal imaging, as well as for various therapeutic approaches including chemotherapy, gene therapy, hyperthermia therapy, photodynamic therapy, radiation therapy, or combination therapy, even imaging-guided therapy. Compared with other inorganic biomaterials such as silica-, carbon-, and gold-based biomaterials, CaXs biomaterials can dissolve into nontoxic ions and participate in the normal metabolism of organisms. Thus, they offer safer clinical solutions for disease theranostics. This review focuses on the state-of-the-art progress in CaXs biomaterials, which covers from their categories, characteristics and preparation methods to their bioapplications including diagnosis, treatment, and theranostics. Moreover, the current trends and key problems as well as the future prospects and challenges of CaXs biomaterials are also discussed at the end.

Efectividad de dos barnices en la remineralización de la mancha blanca / Effectiveness of two varnishes in the remineralization of white spots

El objetivo de este trabajo es evaluar clínicamente la efectividad de la remineralización de las manchas blancas (MB) utilizando dos barnices fluorados. Se diagnosticaron 90 superficie sde MB. Los pacientes fueron divididos en tres grupos, GA: tratado con laca fluorada (FNa al 6 por ciento y F2Ca al 6 por ciento; Bifluorid 11/VOCO), GB: tratado con barniz fluorado (FNa al 5 por ciento, Fluoridin N 5/VOCO) y GC: control. Se realizaron tres topicaciones a los 0, 15 y 30 días La remineralización fue evaluada a los 15, 30 y 90 días. El grupo control no mostró remineralización en ninguno de los controles realizados (p menor 0.05. Para el tratamiento con laca (GA), se observó remineralización a los 15 días luego de la 1ra. topicación (p menor 0.01). Mientras que para el barniz (GB) la misma fue registrada a los 30 días (p menor 0.05). El tratamiento de las superficies dentarias con laca fluorada resulta ser más efectivo luego de la primera topicación con respecto al tratamiento con barniz fluorado

Evidence-based medicine and osteoporosis: a comparison of fracture risk reduction data from osteoporosis randomised clinical trials.

The goal of osteoporosis therapy is to prevent fractures, and many therapies are available for this disease. Regarding proven fracture benefit, however, the quality of the randomised clinical trial evidence varies substantially among therapies. The purpose of this paper is, therefore, to review the published osteoporosis randomised clinical trial literature and to assess the quality of the evidence. Although more than 35 randomised trials for different therapies were reviewed, only alendronate and vitamin D plus calcium have clearly demonstrated a fracture benefit, with alendronate providing the greatest relative risk reduction. Quality clinical trial fracture data for calcitonin, etidronate, fluoride, hormone replacement therapy, parathyroid hormone, calcitriol (and other vitamin D preparations), vitamin D and calcium monotherapy, and selective oestrogen receptor modulators are either lacking or inconclusive or published only as abstracts.

Formaçäo in vitro de fluoreto de cálcio e fluorapatita em esmalte humano após a aplicaçäo de gel flúor-fosfato acidulado durante 1 e 4 minutos / In vitro calcium fluoride and fluorapatite formation in human dental enamel after apf gel aplication during 1 and 4 minutes

Os autores, através de uma metodologia in vitro, avaliam 2 tempos de aplicaçäo de gel flúor-fosfato acidulado (FFA), 1 e 4 min, em esmalte dental humano hígido. Realizaram análise de fluoreto de cálcio (flúor fracamente ligado ao esmalte) e fluoratita (flúor fortemente ligado ao esmalte). Encontraram, através do teste näo paramétrico de Kruskall-Wallis H, considerando nível de significância de 1 por cento, diferença significante entre o grupo controle e os grupos testes. Näo encontraram diferença significante entre os dois grupos testes

Formaçäo "in vitro" de fluoreto de cálcio sobre esmalte hígido, em funçäo do tempo de aplicaçäo de fluoreto acidulado / Calcium fluoride formation \"in vitro\" on the sound enamel in function of the acidulated fluoride aplication time

A aquisiçäo de flúor na forma de fluoreto de cálcio após aplicaçäo de flúor fosfato acidulado foi avaliada in vitro em funçäo do tempo de aplicaçäo. Dois produtos fluoretados na forma de gel, apresentando concentraçäo semelhante de íons flúor (por volta de 12.300 ppm), foram aplicados em três períodos experimentais de 1, 4 e 60 minutos, sobre superfícies hígidas de esmalte humano, obtidas de terceiros molares inclusos. Foram realizadas análises químicas para avaliar a quantidade de fluoreto de cálcio formada. Os produtos avaliados, Nupro Acidulado (produto A) e Sultan Topex (produto B), foram capazes de produzir a formaçäo de fluoreto de cálcio sobre superfícies hígidas do esmalte humano; entretanto, os fragmentos que receberam a aplicaçäo do produto A sempre apresentaram valores menores de concentraçäo de íons de flúor, em comparaçäo aos que receberam aplicaçäo do produto B. Estas concentraçöes foram estatisticamente iguais para 1 e 4 minutos e menores do que aos 60 minutos, para ambos os produtos. Este estudo demonstrou que a quantidade de fluoreto de cálcio formada sobre esmalte hígido aumentou com o tempo de aplicaçäo de flúor fosfato acidulado; contudo, entre curtos períodos (1 e 4 minutos), a diferença na concentraçäo de fluoreto de cálcio näo foi significativa

Previsores do incremento de cárie em crianças escolares brasileiras / Carious lesions increment in Brazilian school children

Os autores tiveram como objetivo avaliar os parâmetros clínicos, salivares e microbiológicos empregados na tentativa de identificar pacientes de alto risco de incremento de cárie na dentiçäo permanente. Dessa forma, 356 escolares brasileiros, de ambos os sexos, com idades entre 06 e 08 anos no início da pesquisa, foram divididos em dois grupos: grupo controle e grupo tratado. O grupo tratado foi submetido a aplicaçöes tópicas de fluoreto e selantes, com revisäo semestral. Os exames salivares, clínicos e microbiológicos mostraram que, entre os diversos previsores empregados para identificar pacientes de alto risco, apenas o ceos mostrou uma diferença estatisticamente significante com o incremento de cárie na dentiçäo permanente, sendo o único índice com alguma confiança para se prever o risco de desenvolvimento de cárie