Some Mechanical Properties of Dental Stone Specimens after Disinfections by 70% Hospital Sprit


  • Amera Kamal College of Dentistry, Hawler Medical University.



Dental stone, disinfections, surface roughness, compressive strength


Background and objective: The transmission of oral pathogens to impression and subsequently on to gypsum casts had been demonstrated. The aim of the study to investigate the effect of disinfections of type III dental stone casts by spraying and immersion in 70% hospital sprit (ethanol) on the compressive strength and surface roughness at two different time intervals (24 and 48) hours.

Methods: Forty eight cylindrical stone specimens (12 for each group), were prepared for compressive strength and surface roughness testing. Six specimens of each group were tested after (24) hours and the other six after (48) hours.

Results: The study showed no significant differences in values of compressive strength and surface roughness between the control and sprayed groups at (24 and 48) hours, this could be due to the fact that the sprayed specimens absorbs fewer amounts of disinfectants than the immersed groups.

Conclusion: The immersion of the specimens in (70%) ethanol for (10) seconds and (30) minutes decrease the compressive strength and increase the surface roughness.


Metrics Loading ...


Craig RG, Power JM, Wataha JC: Dental Materials: Properties and manipulation. 8th ed, Mosby Company 2004.

Hersek N, Canay S: Tensile strength of type IV dental stone dried in microwave oven. J Prosthet Dent 2002; 87: 499 – 502.

Hussein S: Text Book of Dental Materials. 1st ed, Jaypee Brothers, 2004.

Alter MJ, Krruszon – Mordan D, Nainan OV: The prevalence of hepatitis C virus infection in the USA, 1988 – 1994. New Eng J Med 1999; 341: 556 – 62.

John OL, David JC: Preliminary results from disinfection of irreversible hydrocolloid impression.. J Prosthet Dent 1990; 63: 701 – 7.

Stern MA: An evaluation of dental stone after repeated exposure to spray disinfectants. J Prosthet Dent 1991; 65: 713 – 8.

Mitchell DL, Hariri NM: Quantitative study of bacterial colonization of dental casts. J Prosthet Dent 1997; 78: 518 – 21.

Robert WS: Bactericidal effect of a disinfectant dental stone on irreversible hydrocolloid impressions and stone casts. J Prosthet Dent 1989; 62: 605 – 7.

Hatrick CD, Eakle WS, Bird WF: Dental Materials. Clinical applications for Dental assistants and Dental Hygienists. Saunders, An imprint of Elservier science, 2003.

Abdelaziz KM, Combe EC, Hodges JS: The effect of disinfectant additives on the properties of dental gypsum: 1. Mechanical properties. Prosthet Dent 2002; 11: 161 – 7.

Harte JA, Charlton DG: Characteristics of infection control programs in U.S Air Force Dental Clinics. J Am Dent Assoc 2005; 136: 885 – 92.

ADA Council on Scientific Affairs and ADA Council on Dental Practice. Infection control recommendations for the dental office and the dental laboratory. J Am Dent Assoc 1996; 127: 672 – 80.

Kugel G, Perry RD: Disinfection and communication practices: A survey of USA dental laboratories. J Am Dent Assoc 2000; 131: 786 – 92.

Abdulla MA: Surface detail, compressive strength and dimensial accuracy of gypsum casts after repeated immersion in hypochlorite solution. J Prosthet Dent 2006; 95: 462 – 8.

Berko RY: Effect of madacide disinfectant solution on some of physical and mechanical properties of dental stone. M.Sc. Thesis, University of Baghdad 2001.

Rudd KD: Comparison of effects of tap water and slurry water on gypsum casts. J Prosthet Dent 1970; 24: 563 – 70.




How to Cite

Kamal, A. (2009). Some Mechanical Properties of Dental Stone Specimens after Disinfections by 70% Hospital Sprit. Zanco Journal of Medical Sciences (Zanco J Med Sci), 13(1), 49–54.



Original Articles