A Comparative Evaluation of Abrasion Resistance of Three Commercially Available Type IV Dental Stone, Dried using Three Different Drying Techniques - An In vitro Study

Background: The microwave technique of drying dental stone to achieve improved hardness and strength has been suggested in recent years. However, its effect on the wear properties of dental stone has not been thoroughly examined. Aim: The present study was conducted in vitro to determine the abrasion resistance of three commercially available Type IV dental stones using three different drying techniques. Materials and Methods: A total of 180 samples were prepared from 3 Type IV dental stones; namely Eliterock, Zhermack (Italy), Kalrock, Kalabhai industries (India), and Gyprock (Rajkot, India). Samples were subjected to drying in open air for 2 h, hot air oven at a temp of 230°C for 1 h and microwave oven for 5 min at 900Watts. Abrasion resistance was determined using a customized metallic abrasion resistance tester. Results: Microwave oven drying produced samples with increased abrasion resistance values when compared to samples dried in hot air oven and air-dried specimens. Eliterock showed significantly higher mean abrasion resistance values followed by Kalrock and Gyprock. Conclusion: Drying type IV dental stone in a microwave oven at 900W for 5 min increased the abrasion resistance within short time.