Poly (Methyl Methacrylate)/Biphasic Calcium Phosphate/Nano Graphene Bone Cement for Orthopedic Application

Reconstruction with antibiotic loaded single-side gore-tex "Tartine" methyl-methacrylate cementoplasty for pediatric chest wall reconstruction: A 10-case series

INTRODUCTION

Chest wall reconstruction in children after large resection of tumors may be performed with rigid or soft materials. Cementoplasty is commonly used with the "Sandwich" method i.e. gore-tex meshes surrounding both faces of the cement.

HYPOTHESIS

Is antibiotic loaded single-side gore-tex "Tartine" methyl-methacrylate cementoplasty an interesting alternative to the double-side "sandwich" method for chest wall reconstruction?

MATERIAL AND METHODS

Consecutive patients who were treated from 2011 to 2023 in our hospital were included.

RESULTS

Among the ten children treated with a median 5.6 years follow-up, there were no surgical complications related to the reconstruction, loss of function, infections, post operative complications (versus 22.7% in meta-analysis encompassing the 50 rigid reconstructions reported worldwide) nor scoliosis (versus 25%). Three patients have an asymmetric chest wall appearance.

DISCUSSION

"Tartine" cementoplasty is a simple, low-cost technique for pediatric chest wall reconstruction. It is well tolerated and checks key demands for chest wall reconstructions.

LEVEL OF EVIDENCE

IV; retrospective case series.

Mechanical and thermal properties of PMMA resin composites for interim fixed prostheses reinforced with calcium β-pyrophosphate

Interim restorations are essential in fixed prosthodontics as they provide temporary protection of teeth before the insertion of the permanent restoration. Poly(methyl methacrylate) (PMMA) is widely used in the fabrication of interim-fixed restorations as it is a biocompatible material with a lot of convenient properties. However, it exhibits low impact and tensile strength and therefore it is necessary to be reinforced. Calcium β-pyrophosphate (β-CPP) is considered a promising reinforcing material for dental applications, especially for enamel regeneration due to its stability at low pH and its low wear rate. The aim of this study was to manufacture PMMA/β-CPP composites suitable for fixed-interim restorations and to study their mechanical and thermal properties. In order to enhance β-CPP dispersion into PMMA matrix, ball-milling was performed for 1 or 6 h. Three-point bending test was performed to study flexural strength, Dynamic Mechanical Analysis (DMA) to reveal the elastic and viscous moduli along with T_g, Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction Analysis (XRD) to investigate the structure of the materials and SEM for the morphological evaluation of both composite powders and polymerized specimens. Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) experiments were performed to study their thermal properties. A statistically significant increase in flexural strength was found in the 0.5, 0.75 and 1% composite groups after 6 h ball-milling, relative to the control, with the 6 h ball milling mixed specimens, presenting the highest flexural strength values. The brittle fracture type was common to all groups. An obvious improvement of the mechanical properties and a slight improvement in the thermal stability of the composite materials values were also observed as β-CPP content was increased, while T_g values were statistically not-affected.