a roughness study of ytterbium-doped potassium yttrium tungstate (yb: kyw) thin-disk femtosecond ablated dentin
نویسندگان
چکیده
introduction: the aim of this study was to evaluate the morphological changes and quantitatively assess the roughness of dentin after the ablation with a ytterbium-doped potassium yttrium tungstate (yb: kyw) thin-disk femtosecond pulsed laser of different fluences, scanning speeds and scanning distances. method: twelve extracted human premolars were sectioned into crowns and roots along the cementum-enamel junction, and then the crowns were cut longitudinally into sheets about 1.5 mm thick with a cutting machine. the dentin samples were fixed on a stage at focus plane. the laser beam was irradiated onto the samples through a galvanometric scanning system, so rectangular movement could be achieved. after ablation, the samples were examined with a scanning electron microscope and laser three-dimensional profile measurement microscope for morphology and roughness study.with increasing laser fluence, dentin samples exhibited more melting and resolidification of dentin as well as debris-like structure and occluded parts of dentinal tubules. results: when at the scanning speed of 2400mm/s and scanning distance of 24μm, the surface roughness of dentin ablated with femtosecond pulsed laser decreased significantly and varied between values of dentin surface roughness grinded with two kinds of diamond burs with different grits. when at the scanning speed of 1200mm/s and scanning distance of 12μm, the surface roughness decreased slightly, and the surface roughness of dentin ablated with femtosecond pulsed laser was almost equal to that grinded with a low grit diamond bur. conclusion: this study showed that increased laser influence may lead to more collateral damage and lower dentin surface roughness, while scanning speed and scanning distance were also negatively correlated with surface roughness. adequate parameters should be chosen to achieve therapeutic benefits, and different parameters can result in diverse ablation results.
منابع مشابه
Yttrium-doped lead tungstate crystals
In this paper we present results of a study on the yttrium doping in lead tungstate crystals. The crystal growth by modified Bridgman method is described. Results of trace analysis on raw materials and crystals are presented. The segregation coefficient of yttrium ions in lead tungstate crystals was determined. The scintillation emission and longitudinal transmittance spectra, light output, dec...
متن کاملSolid-state Laser Cooling of Ytterbium-doped Tungstate Crystals
Anti-Stokes fluorescence can be used to cool a material if its radiative quantum efficiency is nearly unity. Until recently, the only solid which had shown net cooling was an ytterbium-doped heavy metal fluoride glass. Reasons for the lack of success with other materials include energy transfer to unwanted impurities, trapping of the fluorescence by internal reflection and reabsorption, and non...
متن کاملFemtosecond Yb:CaGdAlO4 thin-disk oscillator.
A mode-locked thin-disk laser based on Yb:CALGO is demonstrated for the first time. At an average output power of 28 W we obtained pulses with a duration of 300 fs and a pulse energy of 1.3 μJ. 197 fs pulses with 0.9 μJ of energy were achieved at an average output power of 20 W. The shortest pulse duration measured in our experiments was 135 fs with a spectrum centered at 1043 nm. The experimen...
متن کاملA study on yttrium doping in lead tungstate crystals
In this paper we present results of a study on the yttrium doping in lead tungstate crystals. The crystal growth by modified Bridgman method is described. Results of trace analysis on raw materials and crystals are presented. The segregation coefficient of yttrium ions in lead tungstate crystals was determined. The scintillation emission and longitudinal transmittance spectra, light output, dec...
متن کاملContinuous-wave laser operation of disordered double tungstate and molybdate crystals doped with ytterbium
Several ytterbium doped disordered doubles tungstate and molybdate crystals, NaGd(WO4)2, NaLa(WO4)2, NaLa(MoO4)2 and LiGd(MoO4)2, were grown with sufficient Yb-doping and optical quality. The crystal field splitting of the Yb 3+ multiplets and the lifetimes are similar to the biaxial monoclinic double tungstates but the peak absorption cross sections are roughly one order of magnitude lower. Ro...
متن کاملThe selective antenna effect of tungstate anions for Tb-doped layered yttrium hydroxynitrate.
A simple way to detect and remove trace amounts of WO4(2-) ions from an aqueous solution was demonstrated by their light-harvesting ability and selective excitation energy transfer to a Tb-doped layered yttrium hydroxynitrate matrix.
متن کاملمنابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
journal of lasers in medical sciencesجلد ۵، شماره ۱، صفحات ۳۲-۳۸
کلمات کلیدی
میزبانی شده توسط پلتفرم ابری doprax.com
copyright © 2015-2023