ObjectiveMicrobial aggregation around dental implants can lead to loss/loosening of the implants. This study was aimed at surface treating titanium microimplants with silver nanoparticles (AgNPs) to achieve antibacterial properties.MethodsAgNP-modified titanium microimplants (Ti-nAg) were prepared using two methods. The first method involved coating the microimplants with regular AgNPs (Ti-AgNP) and the second involved coating them with a AgNP-coated biopolymer (Ti-BP-AgNP). The topologies, microstructures, and chemical compositions of the surfaces of the Ti-nAg were characterized by scanning electron microscopy (SEM) equipped with energy-dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). Disk diffusion tests using Streptococcus mutans, Streptococcus sanguinis, and Aggregatibacter actinomycetemcomitans were performed to test the antibacterial activity of the Ti-nAg microimplants.ResultsSEM revealed that only a meager amount of AgNPs was sparsely deposited on the Ti-AgNP surface with the first method, while a layer of AgNP-coated biopolymer extended along the Ti-BP-AgNP surface in the second method. The diameters of the coated nanoparticles were in the range of 10 to 30 nm. EDS revealed 1.05 atomic % of Ag on the surface of the Ti-AgNP and an astounding 21.2 atomic % on the surface of the Ti-BP-AgNP. XPS confirmed the metallic state of silver on the Ti-BP-AgNP surface. After 24 hours of incubation, clear zones of inhibition were seen around the Ti-BP-AgNP microimplants in all three test bacterial culture plates, whereas no antibacterial effect was observed with the Ti-AgNP microimplants.ConclusionsTitanium microimplants modified with Ti-BP-AgNP exhibit excellent antibacterial properties, making them a promising implantable biomaterial.

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Introduction: The cost of orthodontic treatment in most of the industrialized countries may considerably differ from those in third world countries. The lesser cost of orthodontic treatment, high pricing of orthodontic inventory and poor economic conditions of the people strengthen the notion of 'recycling' even more. Objectives:To compare the shear bond strengths of .022 slot pre-adjusted edgewise brackets with conventional mesh base design recycled by two different chair-side techniques, one being flaming/heating and other being sandblasting. Materials & Method:The sample involved eighty extracted human premolars with .022 slot pre-adjusted edgewise brackets (Orcmo, USA) bonded onto the lingual surface. After initial de-bonding the bracket base was studied under a scanning electron microscope at different magnifications for aperture size, mesh continuity and surface roughness. The brackets were re-bonded on to the labial surface of the same premolars and then debonded using a Universal Testing Machine to produce a shear force at the tooth bracket interface. The aim of any bracket recycling system is to remove the adhesive residue from the bracket base completely without causing structural damage, in order to eliminate all impurities related to orthodontic treatment, so that the bracket can be rebonded to the enamel surface producing a new adhesive bond of adequate strength. 4-7According to Tavares et al, 8 the methods of recycling brackets may be classified as Industrial (chemical and heating) and chair-side use of a tungsten carbide bur, heating and sandblasting.

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