Title of dissertation: HIGH ELASTIC MODULUS NANOPOWDER REINFORCED RESIN COMPOSITES FOR DENTAL APPLICATIONS Yijun Wang, Doctor of Philosophy, 2007 Dissertation directed by: Associate Professor Isabel K. Lloyd Department of Material Science and Engineering Dental restorations account for more than $3 billion dollars a year on the market. Among them, all-ceramic dental crowns draw more and more at...

Growing patient demands for esthetics and concerns about environmental contamination by amalgam have led to a large increase in restorations using dental composites. Polymerization of dental composites occurs through a chain reaction that is induced by free radicals. If composite is exposed to air during this process, oxygen in the air decreases the excitability of the photo initiator and stabi...

OBJECTIVES This work aims to review the key factors affecting the polymerization efficiency of light-activated resin-based composites. The different properties and methods used to evaluate polymerization efficiency will also be critically appraised with focus on the developments in dental photopolymer technology and how recent advances have attempted to improve the shortcomings of contemporary ...

OBJECTIVES Flowable dental composites are used as restorative materials due to their excellent esthetics and rheology. However, they suffer from inferior mechanical properties compared to conventional composites. The aim of this study was to reinforce a flowable dental composite with TiO2 nanotubes (n-TiO2) and to assess the effect of n-TiO2 surface modifications on the mechanical properties of...

CaptekTM (Precious Chemical USA Inc., Apopka, Florida) is a new, innovative development in dental materials. It is a dental alloy that can be defined as a composite material because it is internally composed of two different alloys. CaptekTM is a high gold content alloy (88% by weight) and is used in porcelain-fused-to-metal dental crowns and bridges. Composite metals containing metallic matrix...

INTRODUCTION healthy dietary habits are considered to improve oral health and tooth quality. Caries treatment comprises tooth restoration with dental composites and sealants, almost all (> 90%) of which contain bisphenol A (BPA). Study hypotheses were: a) breakfast and oral hygiene habits are important factors in dental caries development; and b) dental caries treatment with epoxy-resins entail...

Composites of glutamine-based segmented polyurethanes with 5 to 25 wt.% bioactive glass nanoparticles were prepared, characterized, and their mineralization potential was evaluated in simulated body fluid. Biocompatibility with dental pulp stem cells was assessed by MTS to an extended range of compositions (1 to 25 wt.% of bioactive glass nanoparticles). Physicochemical characterization showed ...

Amorphous calcium phosphate (ACP), a postulated precursor in the formation of biological hydroxyapatite, has been evaluated as a filler phase in bioactive polymeric composites that utilize dental monomers to form the matrix phase on polymerization. In addition to excellent biocompatibility, these composites provided sustained release of calcium and phosphate ions into simulated saliva milieus. ...

The traditional parameters used to evaluate dental composites in the laboratory have been working time, polymerization contraction, compressive, tensile, shear, and bond strength, resistance to indentation, water sorption and solubility, leakage, color stability by the 24-hour ultraviolet lamp test, and thermal coefficient of expansion. Other less well documented properties of composites are th...

We apply terahertz (THz) time-domain spectroscopy for monitoring the curing process of three different light-curing dental composites. Exact knowledge of the sample thickness is required for a precise determination of the THz dielectric parameters, as the materials exhibit shrinkage when they are cured. We find very small but significant changes of the THz refractive index and absorption coeffi...