Silicon-calcium phosphate ceramics and silicon-calcium phosphate cements: Substrates to customize the release of antibiotics according to the idiosyncrasies of the patient.

Bone substitutes based on calcium phosphates can be classified in two major groups: ceramics and cements. Both are biomaterials with excellent biocompatibility that have been studied as local delivery systems for drugs. This study aims to evaluate drug-release kinetics in silicon beta-tricalcium phosphate ceramics (Si-ß-TCP) and in silicon calcium phosphate cements (Si-CPCs). We want to investigate if the differences in composition and in structure of the Si-ß-TCP and the Si-CPC may influence for drug loading and in its release kinetics from the biomaterial. The results obtained indicate that all drug-loaded materials were efficient to tailor drug release kinetics and inhibited the growth of Staphylococcus aureus. The cements prepared with high concentrations of silicon (80% Si-CPC) present zero-order release kinetics, independent of the drug concentration loaded. Si-ß-TCP and Si-CPC offer a simple technology that could serve to personalize the delivery of bioactive molecules according to each patient's needs in the treatment of bone conditions, not only limited to prophylaxis, but also for the treatment of bone infection.

A new iron calcium phosphate material to improve the osteoconductive properties of a biodegradable ceramic: a study in rabbit calvaria.

ß-tricalcium phosphate (ß-TCP) is an osteoconductive and biodegradable material used in bone regeneration procedures, while iron has been suggested as a tool to improve the biological performance of calcium phosphate-based materials. However, the mechanisms of interaction between these materials and human cells are not fully understood. In order to clarify this relationship, we have studied the iron role in ß-TCP ceramics. Iron-containing ß-TCPs were prepared by replacing CaCO3 with C6H5FeO7 at different molar ratios. X-ray diffraction analysis indicated the occurrence of ß-TCP as the sole phase in the pure ß-TCP and iron-containing ceramics. The incorporation of iron ions in the ß-TCP lattice decreased the specific surface area as the pore size was shifted toward meso- and/or macropores. Furthermore, the human osteoblastlike cell line MG-63 was cultured onto the ceramics to determine cell proliferation and viability, and it was observed that the iron-ß-TCP ceramics have better cytocompatibility than pure ß-TCP. Finally, in vivo assays were performed using rabbit calvaria as a bone model. The scaffolds were implanted for 8 and 12 weeks in the defects created in the skullcap with pure ß-TCP as the control. The in vivo behavior, in terms of new bone formed, degradation, and residual graft material were investigated using sequential histological evaluations and histomorphometric analysis. The in vivo implantation of the ceramics showed enhanced bone tissue formation and scaffold degradation for iron-ß-TCPs. Thus, iron appears to be a useful tool to enhance the osteoconductive properties of calcium phosphate ceramics.

Odontomas complejos / Complex Odontomas

Introducción: Los odontomas son uno de los tumores odontogénicos más frecuentes. Su etiología es desconocida, aunque se han implicado numerosos factores como traumatismos, infecciones y mutaciones genéticas entre otros. El diagnóstico diferencial debe establecerse con el fibroma amelobástico, el fibroodontoma ameloblástico y el odontoameloblastoma, siendo el tratamiento de elección de estos tumores la enucleación quirúrgica. El objetivo de este artículo es presentar el caso clínico de un paciente con un odontoma complejo mandibular, así como los resultados de la revisión bibliográfica hecha al respecto. Caso clínico: Se expone el caso de un paciente varón, que es remitido a nuestras consultas por el hallazgo casual de una lesión ósea mandibular derecha, radiopaca, amorfa, de 2 cm de diámetro, en relación con el cordal 48 incluido y sugerente de odontoma complejo, sin sintomatología dolorosa niinflamatoria acompañante. Tras un adecuado estudio radiológico y ante el diagnóstico de presunción de odontoma complejo, se procede a su extirpación quirúrgica y posterior análisis anatomopatológico para su diagnóstico de confirmación. Conclusiones: Los odontomas se clasifican en compuestos y complejos, siendo los primeros los más frecuentes. Su sintomatología es escasa o nula, por lo que su hallazgo es casual en la mayoría de las ocasiones. El tratamiento de elección es quirúrgico, con un pronóstico favorable y escasas recidivas (AU)

Introduction: The odontomas are one of the most frequent odontogenic tumours. Their etiology is unknown, although numerous factors have been implicated, such as traumatisms, infections and genetic mutations, among others. The differential diagnosis must be established with ameloblastic fibroma, ameloblastic fibroodontoma and odontoameloblastoma, with surgical enucleation being the treatment of choice of these tumours. The objective of this article is to present the clinical case of a patient with a complex mandibular odontoma, as well as the results of the bibliographical review made in this regards. Clinical case: The case is described of a male patient, referred to our offices because of the casual finding of a right mandibular bone lesion ,radiopaque, amorphous, of 2 cm in diameter, in relation to the included wisdom tooth 48 and suggesting complex odontoma, without painful symptoms or accompanying inflammation. After the appropriate radiological analysis and in view of the presumption diagnosis of complex odontoma, it was surgically removed and subsequent anatomopathological analysis was conducted for the confirmation of the diagnosis Conclusions: Odontomas are classified as compound or complex, with the former being the most frequent. Their symptoms are scarce or nil, for which their finding is casual in the majority of the occasions. The treatment of choice is surgery, with a favourable prognosis and few recurrences (AU)