Linear Dimensional Stability of Irreversible Hydrocolloid Materials Over Time.
The aim of this study was to evaluate the linear dimensional stability of different irreversible hydrocolloid materials over time. A metal mold was designed with custom trays made of thermoplastic sheets (Sabilex, sheets 0.125 mm thick). Perforations were made in order to improve retention of the material. Five impressions were taken with each of the following: Kromopan 100 (LASCOD) [AlKr], which has dimensional stability of 100 hours, and Phase Plus (ZHERMACK) [AlPh], which has dimensional stability of 48 hours. Standardized digital photographs were taken at different time intervals (0, 15, 30, 45, 60, 120 minutes; 12, 24 and 96 hours), using an "ad-hoc" device. The images were analyzed with software (UTHSCSA Image Tool) by measuring the distance between intersection of the lines previously made at the top of the mold. The results were analyzed by ANOVA for repeated measures. Initial and final values were (mean and standard deviation): AlKr: 16.44 (0.22) and 16.34 (0.11), AlPh: 16.40 (0.06) and 16.18 (0.06). Statistical evaluation showed significant effect of material and time factors. Under the conditions in this study, time significantly affects the linear dimensional stability of irreversible hydrocolloid materials.
Department of Dental Materials, School of Dentistry, University of Buenos Aires, Argentina. agarrofe@odon.uba.ar.
Analía B
AB
Garrofé
Department of Dental Materials, School of Dentistry, University of Buenos Aires, Argentina.
Beatriz A
BA
Ferrari
Department of Dental Materials, School of Dentistry, University of Buenos Aires, Argentina.
Mariana
M
Picca
Department of Dental Materials, School of Dentistry, University of Buenos Aires, Argentina.
Andrea E
AE
Kaplan
D003102:Colloids; D003760:Dental Impression Materials / Q000737:chemistry*; D003761:Dental Impression Technique; D008422:Materials Testing; D003765:Models, Dental; D013499:Surface Properties; D013997:Time Factors
D003102:Colloids; D003760:Dental Impression Materials
alginates; dimensional measurement accuracy