José Angel Delgado García-Menocal

Hydrothermal Method for Preparing Calcium Phosphate Monoliths

A new hydrothermal route for preparing biphasic calcium phosphate monoliths is proposed. Firstly, a slurry of b-tricalcium phosphate/ortho-phosphoric acid (b-TCP/H3PO4) is cast into the desired final shape and size to obtain a block composed of dicalcium phosphate dihydrate (DCPD) and b-TCP. This block is then treated in 1.0 M Na2HPO4 at 60 °C in order to hydrolyze the DCPD into Ca10-x(HPO4)x(PO4) 6-x(OH)2-x (CDHA) and Ca8H2(PO4)6 .5H2O (OCP). The result is a monolithic piece which preserves the initial shape and size, but which is composed instead of CDHA, OCP, and b-TCP. During the initial stage, when the pH is slightly alkaline, the product of DCPD hydrolysis is CDHA. However, when a neutral or slightly acidic pH is reached OCP is formed. Test samples processed by this method showed complete conversion of DCPD into CDHA and OCP after 112 h of hydrolysis, and with a compressive strength of 16.2 MPa, similar to cancellous bone.

Calcium phosphate glasses: Silanation process and effect on the bioactivity behavior of glass-PMMA composites

This article presents the results of a study of the efficiency of silanation process of calcium phosphate glasses particles and its effect on the bioactivity behavior of glass- poly(methyl methacrylate) (PMMA) composites. Two different calcium phosphate glasses: 44.5CaO-44.5P2 O5 -11Na2 O (BV11) and 44.5CaO-44.5P2 O5 -6Na2 O-5TiO2 (G5) were synthesized and treated with silane coupling agent. The glasses obtained were characterized by Microprobe and BET while the efficiency of silanation process was determined using Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS) and Thermal Analysis (DTA and TG) techniques. The content of coupling agent chemically tightly bond to the silanated glasses ascended to 1.69 ± 0.02 wt % for BV11sil glass and 0.93 ± 0.01 wt % for G5sil glass. The in vitro bioactivity test carried out in Simulated Body Fluid (SBF) revealed certain bioactive performance with the use of both silanated glasses in a 30% (by weight) as filler of the PMMA composites because of a superficial deposition of an apatite-like layer with low content of CO3 (2-) and HPO4 (2-) in its structure after soaking for 30 days occurred.

Evaluation of acrylic bone cements with single and combined antibiotics: Release behavior and in vitro antibacterial effectiveness

ABSTRACTThis work studied the eluting behavior of Ciprofloxacin, Meropenem and Ceftazidime (and their mixtures) with that of Gentamicin from antibiotic loaded bone cements (ALBCs). In vitro release was followed by UV-Vis for 30 days and a semi-empirical eluting model that considers the processes of dissolution and diffusion was proposed: . The antimicrobial efficacy against P. aeruginosa and S. aureus of the prepared ALBCs was also evaluated. The results showed that the amount of antibiotic released increased when Ciprofloxacin/Meropenem or Ciprofloxacin/Ceftazidime were used and that their antibacterial inhibitory effect against microorganisms tested was improved as a consequence of the synergistic effect.ABSTRACT This work studied the eluting behavior of ciprofloxacin, meropenem, and ceftazidime (and their mixtures) with that of gentamicin from antibiotic-loaded bone cements (ALBCs). In vitro release was followed by UV–Vis for 30 days and a semiempirical eluting model that considers the processes of dissolution and diffusion were proposed: . The antimicrobial efficacy against Pseudomonas aeruginosa and Staphylococcus aureus of the prepared ALBCs was also evaluated. The results showed that the amount of antibiotic released increased when ciprofloxacin/meropenem or ciprofloxacin/ceftazidime was used and that their antibacterial inhibitory effect against microorganisms tested was improved as a consequence of the synergistic effect. GRAPHICAL ABSTRACT

Effectiveness and Therapeutic Safety Using Β-Tricalcium Phosphate in Oral Bone Defects

Aim: To determine the effectiveness and therapeutic safety with β-tricalcium phosphate (Biograft-G®) in oral bone defects. Methods: A Phase III, multicenter, uncontrolled clinical trial (Classification of medical devices), to assess the Biograft-G® Biomaterials Center, University of Havana was made. All the population of the clinical trial was choose from four Cuban provinces and 121 patients was the sample selected for the studies. All the patients gave their consent to participate. The patients included in the study were: ages between 18 and 75 years, both sexes that could be treated surgically. Patients with malignant neoplasms of any location, diabetic patients who were decompensated or difficult to control, immunosuppressed or immunosuppressed, and mentally retarded patients were excluded. Surgeries were performed in patients requiring dental extraction, alveolar ridge reconstruction, periodontal and periapical surgery. The main variable was a clinical and radiographic appearance, evaluated in four periods (7 days, 1, 3 and 6 months) and levels: Success and Failure. Results: An effectiveness of 97.5% for β-tricalcium phosphate (Biograft-G®) was demonstrated. In all the periods of clinical and radiographic evaluation of it showed gradually reabsorption similar to surrounding healthy tissue, until the complete degradation of the biomaterial. It was determined that adverse treatment (infection, delamination of the material, tenderness and pain) events behaved low. Conclusion: It was concluded high effectiveness and safety of treatment with Biograft-G® in complex oral surgery, with minimal and mild adverse events to treatment.