Solid State Phenomena Vol. 207

Abstract: The linear and non-linear properties of material have gained in both scientific interest and technological importance. Over the last few years, there has been much interest in developing materials with large nonlinearities in order to exploit their potential for use in ultrafast nonlinear optical devices. The different factors that play a role for controlling the refractive indices such as density, molar refraction, photon energy, coordination number, electronic polarizability, field strength of cations, bridging and nonbridging oxygen, and optical basicity are discussed in accordance with the obtained linear refractive index data. The nonlinear phenomena which include intensity dependent on refractive index, excitation energy, dispersion energy, optical energy, metallization criterion, second and third harmonic generations have been discussed. Finally, the optical application, viz. photonics, electro-optics, photo chromic and magneto-optics of the material have been studied. Keywords: Glass; linear; nonlinear indices; optical application

Abstract: The paper reports the visible-NIR luminescence and time-resolved emission spectral profiles of Nd³⁺, and Er³⁺ doped silver zinc borate glasses. Steady state luminescence (SSL) and time-resolved emission spectroscopy (TRES) were used to evaluate how the randomness of the network can influence the emission from rare earth ions in the visible region. As expected the composition of the glasses strongly influences the emission bands of the dopant ions. The lack of homogeneity in the glass network results in distorted and broad luminescence spectra. Moreover, time-resolved techniques allowed the visualization of the time dependence of the spectra. The luminescence was also characterized using steady state techniques and the strongest NIR emission peaks were ⁴F_3/2 à ⁴I_l1/2 for Nd ³⁺ and ⁴I_13/2 à ⁴I_l5/2 for Er ³⁺ ions respectively.Key words: Time-resolved emission spectra; decay associated spectra; Nd³⁺ and Er³⁺; Silver zinc borate glasses

Abstract: Lead arsenate glasses containing different concentrations of CuO ranging from 0 to 1.5 mol% (in steps of 0.3 mol%) were prepared by melt quenching method. Further, samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and differential scanning calorimetric analysis (DSC). A number of studies viz., optical absorption, luminescence and FTIR spectra also have been carried out on these glasses. XRD and SEM studies have confirmed that the prepared samples are of amorphous in nature. DSC results indicate the more structural degree of disorder for glass containing 1.5 mol% of CuO. From the IR spectra, it is observed that the intensity of bands due to ν₁, ν₂, ν₃ and ν₄ and vibrations of AsO₃ group seems to be decreasing with shifting of the metacentres towards slightly higher wavenumber. The optical absorption and luminescence studies have indicated that copper exist in both the valence states viz., Cu⁺ and Cu²⁺. Finally the analyses of all results indicate that there will be growing degree of structural disorder with increase in the content of CuO. Keywords: Arsenate glasses, copper oxidation, optical absorption, luminescence

Abstract: Glass system of composition Li₂O-Na₂O-B₂O₃: Fe₂O₃ with replacing alkali oxides one by another have been prepared via melt quenching. Further, the samples were characterized by X-ray diffraction. XRD studies have indicated that the prepared samples were amorphous in nature. Dielectric properties (constant ε , loss tan δ, a.c. conductivity σ_ac over a wide range of frequency and temperature) of these glasses have also been explored. The activation energy for ac conduction is estimated to be the lowest for glass F₂₅ and the highest for glass F₀. Finally the study on dielectric properties indicated that the ac conduction is predominantly ionic in nature in the samples containing high content of Li₂O. Keywords: Borate glasses; dielectric properties; alkali effect

Abstract: Jaw cysts are common lesions in the maxillofacial area. Their treatment varies from surgical enucleation alone to enucleation followed by bone grafting depending on the size of the lesion. Various bone substitutes ranging from autografts, allografts, xenografts and alloplasts have been tried and tested with varying degrees of success. Here, the author present a case report of large cystic lesion of anterior maxilla and its treatment using a glass reinforced hydroxyapatite composite (Bonelike^®) following enucleation. One year follow up demonstrated satisfactory clinical and radiological treatment outcomes.Keywords: Jaw cyst, enucleation, defect filling, alloplast, Bonelike^® , bone grafts.

Abstract: Implant therapy has provided the clinician a wide variety of treatment options with respect to the replacement of missing natural teeth. With more number of dentists practicing implant dentistry, one is likely to be presented with peri-implantitis and implant related failures in day to day practice. Peri-impant mucositis can be reversed by elimination of the biofilm but peri-implantitis which results in bone loss and subsequent exfoliation of the implant if left unattended have to be treated using a regenerative approach in addition to conventional non surgical therapy. The present case demonstrates the guided bone regeneration procedure using a glass-reinforced HA and collagen membrane in the treatment of an intrabony defect around the implant. Nine months post operative radiograph revealed complete resolution of the defect. This novel composite alloplast shows promise in treating such lesions.Keywords: Peri-implantitis, Guided bone regeneration, Alloplast, Dental implant, Bone graft, Collagen membrane, Implant decontamination.