Dimensional accuracy of 2 irreversible hydrocolloid alternative impression materials with immediate and delayed pouring.
OBJECTIVE
To assess dimensional accuracy and stability of 2 irreversible hydrocolloid alternative impression materials with immediate and delayed pouring.


METHODS
Two alternative impression materials, AlgiNot FS and Position Penta Quick, were compared with a traditional irreversible hydrocolloid, Jeltrate Plus antimicrobial alginate. Impressions were made of a metal model with 4 cylinders of known dimensions, with pouring performed immediately or after 4 hours of storage. A digital micrometer was used to measure cylinder diameter on the model and the poured casts. Dimensional changes were analyzed according to American National Standards Institute/American Dental Association (ANSI/ADA) Specification 19 (2004 version) (α=0.05).


RESULTS
There were significant differences among the 3 materials, between the 2 pour times and as a function of storage time (multivariate analysis of variance, p<0.001). One-way analysis of variance revealed no significant differences between the 2 alternative impression materials, but changes for these materials differed significantly from those for the traditional impression material for immediate (p<0.05) and 4-hour (p<0.001) pouring. Linear dimensional changes for the 2 substitute materials were within the limits of the ANSI/ADA specification.


CONCLUSIONS
With immediate pouring, both alternative impression materials exhibited minimal dimensional changes, which were maintained or reduced with 4-hour pouring. For both pouring times, these changes were less than 0.5%.


CONCLUSIONS
The minimal dimensional changes observed with these irreversible hydrocolloid alternative impression materials after 4 hours of storage may save chairside time and help to produce accurate results for procedures such as partial denture framework, surgical guides, and pediatric and orthodontic devices.
Department of Dentistry, Faculty of Medicine and Dentistry, University of Alberta Edmonton, AB. unassar@ualberta.ca
Usama
U
Nassar
Bayan
B
Hussein
Andrea
A
Oko
Jason P
JP
Carey
Carlos
C
Flores-Mir
D000464:Alginates / Q000737:chemistry*; D000704:Analysis of Variance; D003102:Colloids / Q000737:chemistry*; D003760:Dental Impression Materials / Q000737:chemistry*; D003761:Dental Impression Technique / Q000295:instrumentation*; D006801:Humans; D008422:Materials Testing; D009930:Organic Chemicals / Q000737:chemistry; D013997:Time Factors
D000464:Alginates; D003102:Colloids; D003760:Dental Impression Materials; D009930:Organic Chemicals; C043594:Jeltrate