An in vitro investigation into the physical properties of irreversible hydrocolloid alternatives.
BACKGROUND
A number of manufacturers have introduced new products that are marketed as alternatives to irreversible hydrocolloid impression materials. However, there is a paucity of laboratory and clinical research on these products compared to traditional irreversible hydrocolloid.


OBJECTIVE
The purpose of this study was to evaluate the detail reproduction, gypsum compatibility, and linear dimensional change of 3 recently introduced impression materials designed as alternatives to irreversible hydrocolloid.


METHODS
The tested materials were Position Penta Quick, Silgimix, and AlgiNot. An irreversible hydrocolloid impression material, Jeltrate Plus Antimicrobial, served as the control. The parameters of detail reproduction, gypsum compatibility, and linear dimensional change were tested in accordance with ANSI/ADA Specifications No. 18 and 19. The gypsum compatibility was tested using a type III stone (Microstone Golden) and a type IV stone (Die-Keen Green). The data were analyzed using the Kruskal-Wallis rank test and the Mann-Whitney U test (α=.05).


RESULTS
The test materials demonstrated significantly (P<.001) better detail reproduction than the control material. Silgimix exhibited the best compatibility with Microstone, whereas AlgiNot and Position Penta Quick exhibited the best gypsum compatibility with Die-Keen. An incompatibility was observed over time between the Jeltrate control material and the Microstone gypsum material. For linear dimensional change, the mean dimension of the control material most closely approximated the distance between the lines on the test die, but it exhibited the greatest variability in measurements. All of the test materials exhibited linear dimensional change within the ADA's accepted limit of 1.0%.


CONCLUSIONS
The 3 new impression materials exhibited better detail reproduction and less variability in linear dimensional change than the irreversible hydrocolloid control. Gypsum compatibility varied with the brand of gypsum used, with an incompatibility identified between the control material (Jeltrate Plus Antimicrobial) and Microstone related to surface changes observed over time.
Department of Restorative Dentistry, Loma Linda University School of Dentistry, Loma Linda, CA 92354, USA. rdpatel@llu.edu
Rishi D
RD
Patel
Mathew T
MT
Kattadiyil
Charles J
CJ
Goodacre
Myron S
MS
Winer
D000464:Alginates; D002133:Calcium Sulfate; D003102:Colloids; D003760:Dental Impression Materials / Q000737:chemistry*; D003799:Dental Stress Analysis; D004344:Drug Incompatibility; D008422:Materials Testing; D055595:Mechanical Phenomena; D003765:Models, Dental; D015203:Reproducibility of Results; D012828:Silicones
D000464:Alginates; D003102:Colloids; D003760:Dental Impression Materials; D012828:Silicones; D002133:Calcium Sulfate