Dimensional stability of polyvinyl siloxane impression material reproducing the sulcular area.
The dimensional stability of a thin intra sulcular impression material reproducing the preparation finish line was evaluated. Impressions were taken of a stainless-steel master model of a simulated abutment with a 'gingival sulcus' using Express regular, Express fast and Aquasil. The putty-wash two-step technique was applied with spacer thicknesses of 0.5, 1 and 1.5 mm. Mid mesiodistal and bucco-lingual measurements were taken directly from the sulcular impression material after 0.5, 2, 24, 48 and 72 h via a Toolmaker's microscope. The discrepancies between the measurements of the impression material and the master model were calculated. The discrepancies changed significantly over time (p<0.001). The use of a 0.5 mm spacer resulted in a negative deviation from the model (2-46 µm), minimally after 2 h. The use of 1 and 1.5 mm spacers showed a positive deviation from the model (21-52 µm) and both are equally recommended. Investment can be postponed until 72 h.
Department of Oral Rehabilitation, the Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
Shifra
S
Levartovsky
Guy
G
Levy
Tamar
T
Brosh
Noga
N
Harel
Yehuda
Y
Ganor
Raphael
R
Pilo
D000044:Dental Abutments; D003760:Dental Impression Materials / Q000737:chemistry*; D003761:Dental Impression Technique; D005881:Gingiva / Q000033:anatomy & histology*; D006801:Humans; D016014:Linear Models; D008422:Materials Testing; D003765:Models, Dental; D011145:Polyvinyls; D012833:Siloxanes
D003760:Dental Impression Materials; D011145:Polyvinyls; D012833:Siloxanes; C034183:vinyl polysiloxane