The Effects of Custom Tray Material on the Accuracy of Master Casts
Ramin Mosharraf, Sina Shafa, Zeinab Zaree
Citation Information :
Mosharraf R, Shafa S, Zaree Z. The Effects of Custom Tray Material on the Accuracy of Master Casts. J Contemp Dent Pract 2008; 9 (6):49-56.
In addition to the impression material, the type of impression tray influences the accurate dimensional transfer of the size and position of the teeth to the master cast. The aim of this study was to determine the accuracy of master casts produced from an alginate impression material using a visible-light-curing resin and autopolymerizing polymethyl methacrylate resin custom tray materials.
Methods and Materials
Two types of custom trays were fabricated from a stainless steel master model with three index studs. Twenty-two irreversible hydrocolloid impressions were made of the master model and then poured with a Type III dental stone. The distances between the reproduced index studs were measured to +/- 0.01 mm with a digital caliper. A one-way analysis of variance (ANOVA) and T-test were used for data analysis.
Results
There were no significant differences between the two tray materials for any of the three distances. There were no statistical differences between the master model and the casts made from the two tray materials in the length dimension, but there were significant differences in the vertical dimension. In terms of the width dimension there was a significant difference only between the cold curing group and the master model.
Conclusion
Within the limitations of this study, the dimensions of stone casts poured from an impression made using a light-cured tray did not differ significantly from those created from impressions made using autopolymerizing acrylic trays. However, working dies from the light-curing tray impressions were more accurate buccolingually than those from the autopolymerizing acrylic trays.
Clinical Significance
The accuracy of master cast reproduction using visible-light-curing resin or an autopolymerizing polymethyl methacrylate resin custom tray material is acceptable. Although autopolymerizing resin materials require less equipment and are relatively more inexpensive, light-cure tray materials may be the material of choice for custom tray fabrication due to greater accuracy in the buccolingual dimension.
Citation
Shafa S, Zaree Z, Mosharraf R. The Effects of Custom Tray Material on the Accuracy of Master Casts. J Contemp Dent Pract 2008 September; (9)6:049-056.
The effect of storage time on the accuracy and dimensional stability of reversible hydrocolloid impression material. J Prosthet Dent 2001; 86(3):244-50.
The measurement of distortion: theoretical considerations. J Prosthet Dent 1977; 37(5):578-86.
Accuracy of four types of rubber impression materials compared with time of pour and a repeat pour of models. J Prosthet Dent 1985; 53(4):484-90.
Comparison of conventional paint-on die spacer and those used with the all-ceramic restorations. J Prosthet Dent 1990; 63(2):151-5.
The effect of tray selection, viscosity of impression material, and sequence of pour on the accuracy of dies made from dual-arch impressions. J Prosthet Dent 2003; 90(2):143-9.
Effect of operator variability on void formation in impressions made with an automixed addition silicone. Aust Dent J 1992; 37(1):35-8.
[Effects of different tray types on the resulting impression]. Dtsch Zahnarztl Z 1989;44(8):624-7. [Article in German].
Evaluation of factors affecting the accuracy of impressions using quantitative surface analysis. Oper Dent 1995; 20(6):246-52.
The Influence of Five Impression Techniques on the Dimensional Accuracy of Master Models. Braz Dent J 2000; 11(1):19-27.
Distortion of impression materials used in the double-mix technique. Scand J Dent Res 1991; 99(4):343-8.
Evaluation of the methods for dislodging the impression tray affecting the dimensional accuracy of the abutments in a complete dental arch cast. J Prosth Dent 1989; 61(1):54-8.
A laboratory study of dimensional changes for three elastomeric impression materials using custom and stock trays. Aust Dent J 1996; 41(6):398-404.
The effect of tray selection on the accuracy of elastomeric impression materials. J Prosthet Dent 1990; 63(1):12-5.
Reversible and irreversible hydrocolloid impression materials. J Am Dent Assoc 1950; 40(2):196-207.
An investigation into methods for maintaining the dimensional stability of alginate impression materials. Br Dent J 1956; 100(1): 42-8.
Dimensional accuracy of three different alginate impression materials. J Prosthodont 1995; 4(3):195-9.
Laser digitization of casts to determine the effect of tray selection and cast formation technique on accuracy. J Prosthet Dent 2002; 87(2): 204-9.
The accuracy of highly filled elastomeric impression materials. J Prosthet Dent 1975; 33(1):67-72.
Time-dependent accuracy of elastomer impression materials. Part II: Polyether, polysulfides, and polyvinylsiloxane. J Prosthet Dent 1981; 45(3):329-33.
Long-term dimensional stability of three current elastomers. J Oral Rehabil 1983; 10(4):325-33.
Dimensional accuracy of dental casts: influence of tray material, impression material, and time. J Prosthodont. 2002 Jun; 11(2):98-108.
The influence of impression trays on the accuracy of stone casts poured from irreversible hydrocolloid impressions. J Prosthet Dent. 1985; 54(3):383-8.
Effect of impression tray design and impression technique upon the accuracy of stone casts produced from a putty-wash polyvinyl siloxane impression material. J Dent 1991; 19(5):283-9.
Effect of impression tray design upon the accuracy of stone casts produced from a single-phase medium-bodied polyvinyl siloxane impression material. J Dent. 1992; 20(3):189-92.
Determining the accuracy of stock and custom tray impression/casts. J Oral Rehabil. 1998; 25(8):645-8.
Dimensional stability of elastomeric impression materials in custommade and stock trays. J Prosthet Dent. 1984; 52(4):514-7.
The influence of tray type and other variables on the palatal depth of casts made from irreversible hydrocolloid impressions. J Prosthet Dent. 2002; 87(1):15-22.
Accuracy of open tray implant impressions: an in vitro comparison of stock versus custom trays. J Prosthet Dent. 2003; 89(3):250-5.
The effects of custom tray material on the accuracy of master casts. J Prosthodont 1998; 7(2):106-10.
Factors affecting the accuracy of elastometric impression materials. J Dent, 2004;32(8):603–6.
A clinical evaluation of the agar alginate combined impression: dimensional accuracy of dies by new master crown technique. J Med Dent Sci 2003; 50(3):231-8.
Dimensional stability and detail reproduction of irreversible hydrocolloid and elastomeric impressions disinfected by immersion. J Prosthet Dent 1998; 79(4):446-53.
Effects of disinfecting irreversible hydrocolloid impressions on the resultant gypsum casts: Part III--Dimensional changes. J Prosthet Dent 1993; 70(6):532-7.
The effect of a range of disinfectant on the dimensional accuracy of some impression materials. Eur J Prosthodont Rest Dent 2004; 12(4):154-60.
The influence of tray type and other variables on the palatal depth of casts made from irreversible hydrocolloid impressions. J Prosthet Dent 2002;87(1):15-22.