Date of Award

Spring 2009

Document Type

Thesis - Restricted

Degree Name

Master of Science (MS)



First Advisor

Berzins, David W.

Second Advisor

Waliszewski, Kenneth J.

Third Advisor

Ziebert, Gerald J.


INTRODUCTION: To overcome the potential deficiencies of hand mixing alginate impression materials, a semiautomatic and auromatic mixing machine were developed to create a more smooth, dense, and bubble-free paste. Despite its smooth and dense consistency, little was known about the materials physical properties. PURPOSE: The purpose of this study was to compare the physical properties and porosity of alginates mixed using three methods: mixed by hand, mixed using a semiautomatic mixing machine, and mixed using an automatic mixing machine. In addition, a correlation between mixing method and porosity will also be investigated. MATERIALS AND METHODS: Three alginate impression materials (Jeltrate, Basis, and ImprEssix) were tested. Elastic recovery, strain in compression and compressive strength were measured according to ANSVADA specification No. 18. Tear strength was measured according to ASTM designation D 624. A microtomography unit (Micro CT) was used to determine percent porosity, pore number, and pore volume of each sample. Five specimens for physical properties, and six specimens for porosity from each material were mixed by hand, mixed using the Alginator II semiautomatic mixing machine, and mixed by the TurboMax automatic mixing machine and tested. CONCLUSIONS: Mixing method and brand of impression material had an effect on the physical properties tested, excluding elastic recovery with regard to mixing method. No single mixing method or brand of impression material displayed optimal physical properties. Tear strength and compressive strength were significantly greater when mixed by hand for Jeltrate and mixed by TurboMax for ImprEssix. For Jeltrate. the Alginator II produced significantly greater percent porosity, pore number, and pore volume compared to the other brands of impression materials. For Basis, there was no significant difference in all properties tested except for tear strength when mixed by the three mixing methods. When using lmprEssix, percent porosity and pore volume were significantly lower when mixed by TurboMax, and correlated clinically by the production of a smooth, dense, bubble-free paste.



Restricted Access Item

Having trouble?