Investigation of threshold energy, absorption coefficient and thermal loading in glass ionomer cement laser removal

Abstract

Purpose: Various kinds of lasers have been developed for the diagnostic and operative application. In dental restoration, the laser is used for removal of remaining dental material. The main benefits of laser applications are patient comfort and pain relief. The primary concern in laser application is a better result for the specific area applied compared to the traditional method. Quality result of laser irradiation could be promised with appropriately controlled laser parameter. Thus, this work aims to determine laser energy threshold, absorption coefficient, and thermal loading of glass ionomer cement (GIC) through the application of Beer-Lambert’s law to enhance the use of Nd:YAG laser in the restorative dental application. Method: 132 tooth samples were collected from the Advanced Medical and Dental Institute, Universiti Sains Malaysia. All the tooth sample were drilled and filled up with GIC dental material. Spectron Pulse Nd:YAG Laser System, SL-805G (1064 nm) was used to irradiate all the samples with various parameter applied; laser energy, number of shots and beam size, thus the depth of GIC removal was obtained. Results: Graph of depth GIC removal against laser energy, was plotted for each number of shots, and beam size that considered in measuring the average of GIC removal efficiency. As a result, the general ET, α, and γ were obtained at 46.82 mJ, 10.79 mm-1 and 505.18 mJ mm-3 respectively.