Comparison of impression techniques and double pouring by dental cast’s accuracy
preliminary clinical-lab trial
Aim: This study compared impression techniques and double pouring by means of cast’s accuracy. Methods: For each patient (n=10), impressions from right maxillary canine to first molar were made with acrylic resin trays and vinyl-polysiloxane using one single-step, and four two-steps techniques: relief with poly(vinyl chloride) film; tungsten-carbide bur/scalpel blade; small movements of the tray; non-relief. Total visible buccal surface area of crowns was measured three times using photographs from patients (Baseline) and casts. Mean area values (mm2) between Baseline and casts differences were analyzed by two-way repeated-measures ANOVA (α=.05; 1-β=85%). Results: No significant differences were observed for Impression Techniques (P=.525), Double Pouring (P=.281), and their interaction (P=.809). Conclusion: All impression techniques and double pouring produced casts with similar accuracy.
2. Davis RD, Schwartz RS. Dual-arch and custom tray accuracy. Am J Dent. 1991 Apr;4(2):89-92.
3. Al-Abidi K, Ellakwa A. The effect of adding a stone base on the accuracy of working casts using different types of dental stone. J Contemp Dent Pract. 2006 Sep 1;7(4):17-28.
4. Silva SC, Messias AM, Abi-Rached FO, de Souza RF, Reis JM. Accuracy of gypsum casts after different impression techniques and double pouring. PLoS One. 2016 Oct 13;11(10):e0164825. doi: 10.1371/journal.pone.0164825.
5. Fano V, Gennari PU, Ortalli I. Dimensional stability of silicone-base impression materials. Dent Mater. 1992 Mar;8(2):105-9.
6. Kumar D, Madihalli AU, Reddy KR, Rastogi N, Pradeep NT. Elastomeric impression materials: a comparison of accuracy of multiple pours. J Contemp Dent Pract. 2011 Jul;12(4):272-8.
7. Anadioti E, Aquilino SA, Gratton DG, Holloway JA, Denry I, Thomas GW, Qian F. 3D and 2D Marginal Fit of Pressed and CAD/CAM Lithium Disilicate Crowns Made from Digital and Conventional Impressions. J Prosthodont. 2014 Dec;23(8):610-7. doi: 10.1111/jopr.12180.
8. Contreras EF, Henriques GE, Giolo SR, Nobilo MA. Fit of cast commercially pure titanium and Ti–6Al–4V alloy crowns before and after marginal refinement by electrical discharge machining. J Prosthet Dent. 2002 Nov; 88(5):467-72.
9. Romeo E, Iorio M, Storelli S, Camandona M, Abati S. Marginal adapatation of full-coverage CAD/CAM restorations: in vitro study using a non-destructive method. Minerva Stomatol. 2009 Mar;58(3):61-72.
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