The elastomeric impression material is the most widely used impression material in contemporary dental practice; their accuracy is critical for the outcome of indirect restorations. The accurate duplicate cast obtained from single impression reduces the professional clinical time, patient inconvenience, and extra material cost.

To compare the accuracy of the cast obtained from various impression methods utilizing elastomer impression materials.

The stainless steel working cast model assembly consisting of two abutments and one pontic area was fabricated. Two sets of six each custom aluminum trays were fabricated, with 5 mm spacer and 2 mm space. The impression methods evaluated in the study were additional silicone putty reline (two step), heavy-light body (one step), monophase (one step), and polyether (one step). Type IV gypsum casts were poured at intervals of 1, 12, 24, and 48 hours. The resultant cast was measured with a traveling microscope for comparative dimensional accuracy. The data obtained were subjected to analysis of variance test at significance level <0.05.

The die obtained from putty reline two-step impression techniques had the percentage of variation for the height -0.36 to -0.97% with 0.40 to 0.90% increase in diameter. One-step heavy-light body impression dies recorded the increased width by 0.50 to 0.80% and height reduced by - 0.73 to -1.21%. The resultant dies from additional silicone monophase impressions had a percentage of variation for width 1.20% and height by-1.34%. The similar value for width and height for polyether was -1.46% and -1.30% respectively.

Putty reline technique dies had better dimensional accuracy after repeated pour followed by dies from heavy-light body additional silicone impression.

The multiple pour cast from putty reline elastomeric impressions is clinically acceptable, while cast from polyether was smaller in dimension.

Haralur SB, Toman MS, Al-Shahrani AA, Al-Qarni AA. Dimensional Accuracy of Multiple Pour Cast from Different Elastomer Impression Techniques. Int J Prosthodont Restor Dent 2016;6(3):51-56.