The effect of processing parameters on characteristics of selective laser sintering dental glass‐ceramic powder

Abstract

Purpose: The purpose of this paper is to report a study about the rapid prototyping method of dental glass‐ceramic restoration.Design/methodology/approach: Dental glass‐ceramic restoration materials have excellent physical and chemical, mechanical, aesthetic and biocompatibility characteristics. However, casting methods adopted at present have complicated procedures and high costs; the forming qualities are especially difficult to control. These problems greatly restrict their clinical application and promotion. Therefore, a new forming process based on selective laser sintering (SLS) technology is proposed. First, dental glass‐ceramic is processed into fine powder through a special heat treatment process. Then, the dental restoration parts are manufactured using SLS without any moulds. In this paper, the effects of processing parameters including laser power, scan speed, scan spacing and preheating temperature on the relative density and mechanical properties of the sintered parts are studied.Findings: The experimental results have shown that for the composite powder of epoxy resin binder E‐12 and K₂O‐Al₂O₃‐SiO₂ series of dental glass‐ceramics, when preheating temperature, layer thickness, laser power, scan speed and scan spacing are, respectively, 30∼35°C, 0.08 mm, 21 W, 1,800 mm/s and 0.10 mm/s, the relative densities of dental glass‐ceramic parts are relatively high; the mechanical properties and forming effect are excellent. The relative density and bending strength of SLS parts under the optimized processing parameters are 37.40 per cent and 2.08 MPa, respectively.Research limitations/implications: This study only concerns the preparation and SLS of the dental glass‐ceramic powders. Further investigations are planned to be conducted on post processing, such as binder decomposition, isostatic press and high temperature sintering.Originality/value: This study will provide a theoretical and technical basis for dental glass‐ceramic restorations of SLS.