Effect of Storage Time and Temperature on Dimensional Stability of Impressions Made with Zinc Oxide Impression Paste
Objectives: This study aimed to assess the effect of storage time and temperature on dimensional stability of impressions made with Cavex Outline zinc oxide impression paste.
Materials and Methods: A round stainless steel mold with five grooves (three horizontal and two vertical) was used in this in-vitro experimental study. Cavex Outline impression paste was prepared according to the manufacturer’s instructions and applied to the mold. The mold was placed on a block and stored at 35°C and 100% humidity for setting. The impressions were poured with stone immediately and also after 30, 120, 240 and 420 minutes and 24 hours. The distance between the vertical lines on the casts was measured and compared with that in the immediately poured cast.
Results: Storage in a refrigerator and at room temperature for zero to seven hours had no significant effect on dimensional stability of the impressions; however, 24 hours of storage in a refrigerator or at room temperature decreased the dimensional stability of Cavex Outline (P=0.001). Also, a significant association was found between dimensional changes following 24 hours of storage in a refrigerator (4°C) and at room temperature (23°C; P<0.01).
Conclusions: The optimal pouring time of Cavex Outline impressions with stone is between zero to seven hours, and 24 hours of storage significantly decreases the dimensional stability.
- Shayegh S, Salari A. A study of the prevalence of edentulous cases in Iran during 1998-1999. J Mash Dent Sch. 2003 Spring;21(1):61-5.
- Ender A, Mehl A. Full arch scans: conventional versus digital impressions-an in-vitro study. Int J Comput Dent. 2011;14(1):11-21.
- Nissan J, Rosner O, Bukhari MA, Ghelfan O, Pilo R. Effect of various putty-wash impression techniq- ues on marginal fit of cast crowns. Int J Periodontics Restorative Dent. 2013 Jan-Feb;33(1):e37-42.
- Gladwin M, Bagby M. Clinical aspects of dental materials: Theory, practice, and cases. 4th ed. Wolters Kluwer, Lippincott Williams & Wilkins, 2013:105.
- Anusavice KJ, Shen C, Rawls HR. Phillips' science of dental materials. 12th ed. Elsevier Health Sciences, Saunders an imprint of Elsevier Inc., St. Louis,2012:152.
- Imbery TA, Nehring J, Janus C, Moon PC. Accuracy and dimensional stability of extended-pour and conventional alginate impression materials. J Am Dent Assoc. 2010 Jan;141(1):32-9.
- Keyf F, Tuna SH, ŞEN M, Safrany A. Water sorption and solubility of different luting and restorative dental cements. Turk J Med Sci. 2007 Mar;37(1):47-55.
- Baker PS, Brandt RL, Boyajian G. Impression procedure for patients with severely limited mouth opening. J Prosthet Dent. 2000 Aug;84(2):241-4.
- ISO 3107:2011(en) Dentistry-Zinc oxide/eugenol cements and zinc oxide/non-eugenol cements.2011.
- Walker MP, Burckhard J, Mitts DA, Williams KB. Dimensional change over time of extended- storage alginate impression materials. Angle Orthod.2010 Nov;80(6):1110-5.
- Ghasemi E, Ebadian B, Badrian H, Asad A. Effect of storage time on dimensional changes of irreversible hydrocolloid impression material. J Isfahan Dent Sch. 2012;7(5)585-91. special issue
- Cohen BI, Pagnillo M, Deutsch AS, Musikant B. Dimensional accuracy of three different alginate impression materials. J Prosthodont. 1995 Sep;4(3):195-9.
- Hollenback GM, Smith DD. A Further study of the physical properties of elastic impression materials. J South Calif Dent Assoc. 1965 Jan;33 (1):32-6.
- Johnson GH, Craig RG. Accuracy of four types
of rubber impression materials compared with time of pour and a repeat pour of models. J Prosthet Dent.1985 Apr;53(4):484-90.
- Eriksson A, Öckert‐Eriksson G, Lockowandt P.Accuracy of irreversible hydrocolloids (alginates) for fixed prosthodontics, A comparison between irrever- sible hydrocolloid, reversible hydrocolloid, and addition silicone for use in the syringe-tray technique. Eur J Oral Sci. 1998 Apr;106(2p1):651-60.
- Schleier PE, Gardner FM, Nelson SK, Pashley DH. The effect of storage time on the accuracy and dimensional stability of reversible hydrocolloid impression material. J Prosthet Dent. 2001 Sep;86(3):
- Erbe C, Ruf S, Wöstmann B, Balkenhol M. Dimensional stability of contemporary irreversible hydrocolloids: Humidor versus wet tissue storage. J Prosthet Dent. 2012 Aug;108(2):114-22.
- Sedda M, Casarotto A, Raustia A, Borracchini A. Effect of storage time on the accuracy of casts made from different irreversible hydrocolloids. J Contemp Dent Pract. 2008 May 1;9(4):59-66.
|Issue||Vol 13, No 3 (2016)|
|Dental Impression Materials Zinc Oxide Cavex|
|Rights and permissions|
|This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.|