Dental Asia May/Jun 2020

50 DENTAL ASIA MAY / JUNE 2020 Behind the Scenes C hange is exciting – also in day-to-day dental lab work. The author switched to using IPS Style layering ceramic some time ago. Before he started working with this ceramic system, he thoroughly tested the material and compared it to the product he had previously used. The main aim of switching to a new ceramic system is to improve the quality of one’s results. We regularly used the fluorapatite- leucite glass-ceramic IPS d.SIGN® in our laboratory. Then, one day, we asked ourselves the following question: Would IPS Style® (the first patented metal-ceramic material containing oxyapatite) offer a sound alternative to our accustomed product? We decided to test the new material on flat cobalt-chromium alloy samples. These test specimens enabled us to take a closer look at the layering ceramic. We used these base metal alloy samples (Colado CC) to examine and compare several properties of IPS d.SIGN and IPS Style: For example shade, brightness, shrinkage, fluorescence and dimensional stability. Conditioning and opaquer application One specimen was oxidised at 950°C with a holding time of one minute. The other sample was treated with a bonding agent. Two metal specimens with different bases were now sufficiently prepared for the application of the ceramic materials. Next, the samples were coated with IPS d.SIGN Paste Opaquer and IPS Style Ceram Powder Opaquer. The opaquer products of both systems have a smooth consistency. We had never used an opaquer in powder form before, so applying the IPS Style material was completely new to us. Nevertheless, we were impressed by its ease of application and the excellent results. Shrinkage behaviour and shade effect In the next step, we compared Dentin and Transpa T Neutral materials as well as the Opal Effect OE1 materials. Each of the ceramics was applied to one of the metal samples. A line was drawn down the middle of the sample with a spatula for the purpose of comparing the shrinkage behaviour. The two different ceramics showed the same colour after firing. It was interesting to note that IPS Style exhibited less horizontal shrinkage than IPS d.SIGN (Fig. 1). The vertical shrinkage of both ceramics was almost identical. The samples were held next to each other and examined under a polarising light. IPS Style was shown to be somewhat brighter than IPS d.SIGN. Both materials exhibited almost the same level of fluorescence. In this comparison, IPS Style was at a slight advantage because its Transpa T Neutral and the Incisal materials displayed a more lifelike fluorescence. Dimensional stability and test results The dimensional stability of the ceramics was clearly visible after the first firing cycle. The IPS Style layers successfully maintained their shape after firing. In contrast, IPS d.SIGN did not retain its shape completely. After this test series, we felt that we had gained enough information about the new material for our purposes. Even though the tests were relatively simple, they provided us with valuable insights into the two ceramic systems. Now, we are ready to compare the two materials on the basis of an actual case study. AN EXCITING CHANGE – A Comparison of the IPS d.SIGN and IPS Style Ceramic Systems By Velimir Žujić Test samples showing shrinkage behaviour. Left: Application of the ceramic on the metal sample. Centre: IPS d.SIGN Right: IPS Style Fig. 1: