These studies dealt with the mechanical and physical properties of used biomaterials, using basically FT-IR, environmental SEM-EDS and mechanical testing (microhardness) to characterize the materials after service. The integument formed onto biomaterial surfaces after exposure to biological fluids was also described for the first time in the orthodontic and broader dental materials literature. The [...]
Adhesives in dentistry and especially orthodontics, provide the necessary retention of restorative materials or appliances to tooth structure. Bonding in orthodontic mainly involves Bis-GMA/TEGDMA-based polymers, applied on acid-treated enamel to provide micromechanical retention. Bond strength, monomer release and degree of cure of the polymeric adhesive are the variables, which modulate the clinical success and [...]
Hard (enamel, bone) and soft tissue (PDL, cartilage) mechanics is a field of fundamental importance for the understanding of the cascade of event accompanying the application of force on tooth crown. Complementary to mechanical testing (hardness, modulus), multitechnique characterization of the structure and composition of tissue provides an insight in the effect of stress [...]
A number of studies examined the forces and moments developed during wire ligation with conventional and self-ligating brackets and force relaxation of polymeric elastics, employing custom-made configurations. These papers revealed that the direction of movement and number of teeth engaged in the arch, significantly affect the force applied to teeth with various wire-bracket combinations. [...]
This research program utilized mechanical testing, metallographic etching, microhardness testing, SEM, and X-ray microtomography to reveal the surface and bulk morphology and structure of brackets of different composition and manufacturing process, i.e., laser-welding, metal-injection-molding (MIM) and Ni-, Au- and Ag-brazing. The ionic release from metals and alloys was studied and the significant biological implications were assessed. [...]
A group of studies have focused on the cytotoxicity of materials and procedures in Orthodontics. Conventional cytotoxicity assessment (MTT, DNA synthesis) involving human gingival or PDL fibroblasts and oestrogenicity using an in vitro model, have been on eluents of alloys and adhesives. The growing body of evidence suggests that additional methods beyond conventional assays [...]
In orthodontics, bonding to enamel has been found to induce structural, color and compositional surface alterations on the host tissue. Microscopic, colorimetric and interfacial compositional studies have elucidated the phenomena associated with etching and bonding. A set of papers focused on the interfacial properties of the enamel-adhesive-bracket interface under different loading conditions, enamel preparations [...]
This group of reserch deals with in vivo assessment of failure rate of various bonding protocols and adhesives as well as effect of techniques or brackets on characteristics of treatment including duration and dental effects. The evidence reported revealed the inconsistency of claims of various manufacturers and suggested clinical treatment protocols based on the [...]
These studies employed XPS, AFM, Auger spectroscopy and SEM-EDS to characterize the surface properties of alloys and single-crystal alumina and polycrystalline ceramics materials. The major differences between surface and bulk structures arise from the direct accessibility of surface molecules for reaction with adjacent phases, and the tendency for surface energy minimization to reach en equilibrium [...]
