Author/Editor		Šušterčič, Dušan
Title		Učinek Erbijevega laserja na zobno sklenino in dentin
Type		monografija
Place		Ljubljana
Publisher		Medicinska fakulteta
Publication year		2003
Volume		str. 88
Language		slo
Abstract		The process of Er:YAG laser ablation of hard dental tissues is not completely understood. This results from diffculties in evaluating the influence of numerous conditions and laser irradiation parameters, complications due to the effects of heat diffusion, absorption and the scattering of the laser beam by the ejected debris during the ablation process. Using an experimental laser system we found that the ablation process is continuous and that the ablation effect is a cumulative effect of the minipulses which compose the single laser pulse. The laser ablation dynamics is different at short compared to long pulse durations, due to the different velocity of the laser ablation front relative to heat diffusion. At higher energy densities and shorter laser pulses, the ablation efficacy is influenced mainly by the absorption and scattering of the laser beam by the ejected debris from the interaction site ("cold ablation"). In contrast, at lower energy densities and longer laser pulses, the ablation effcacy is strongly influenced by heat diffusion causing dissipation of energy from the interaction site. As a result, the laser efficacy is lower and thermal damage in adjacent tissues is more pronounced ("hot ablation"). It was our goal to determine optimal pulse length for hard dental tissue removal and surface conditioning. Optimal pulse length was found to be between 100 and 300 micro s. Likewise, the highest ablation efficacy was achieved with a clinical Er:YAG laser system (Twinlight, Fotona, Ljubljana) at laser pulse length 200 micro s. The ablation of hard dental tissue is initially linearly dependent on the laser energy, but displays a marked saturation. (Abstract truncated at 2000 characters).
Descriptors		LASER SURGERY DENTAL ENAMEL DENTIN COMPOSITE RESINS ACID ETCHING, DENTAL ERBIUM DENTAL BONDING