Accuracy of Ringless Casting and Accelerated Wax-Elimination Technique: A Comparative In Vitro Study

• Published in: Journal of prosthodontics 2014-02, Vol.23 (2), p.157-162
• Main Authors: Prasad, Rahul, Al-Keraif, Abdulaziz Abdullah, Kathuria, Nidhi, Gandhi, P.V., Bhide, S.V.
• Format: Article
• Language: English
• Subjects: alloys; Aluminum Oxide - chemistry; copings; Crowns - standards; Dental Casting Investment - chemistry; Dental Casting Technique - instrumentation; Dental Casting Technique - standards; Dental Etching - methods; Dental Marginal Adaptation; Dental Prosthesis Design - standards; Dentistry; Humans; marginal gaps; Materials Testing; Metal Ceramic Alloys - chemistry; Phosphate-bonded investments; Surface Properties; Temperature; Time Factors; Waxes - chemistry
• ISSN: 1059-941X; 1532-849X
• DOI: 10.1111/jopr.12082

Purpose The purpose of this study was to determine whether the ringless casting and accelerated wax‐elimination techniques can be combined to offer a cost‐effective, clinically acceptable, and time‐saving alternative for fabricating single unit castings in fixed prosthodontics. Materials and Methods Sixty standardized wax copings were fabricated on a type IV stone replica of a stainless steel die. The wax patterns were divided into four groups. The first group was cast using the ringless investment technique and conventional wax‐elimination method; the second group was cast using the ringless investment technique and accelerated wax‐elimination method; the third group was cast using the conventional metal ring investment technique and conventional wax‐elimination method; the fourth group was cast using the metal ring investment technique and accelerated wax‐elimination method. The vertical marginal gap was measured at four sites per specimen, using a digital optical microscope at 100× magnification. The results were analyzed using two‐way ANOVA to determine statistical significance. Results The vertical marginal gaps of castings fabricated using the ringless technique (76.98 ± 7.59 μm) were significantly less (p < 0.05) than those castings fabricated using the conventional metal ring technique (138.44 ± 28.59 μm); however, the vertical marginal gaps of the conventional (102.63 ± 36.12 μm) and accelerated wax‐elimination (112.79 ± 38.34 μm) castings were not statistically significant (p > 0.05). Conclusions The ringless investment technique can produce castings with higher accuracy and can be favorably combined with the accelerated wax‐elimination method as a vital alternative to the time‐consuming conventional technique of casting restorations in fixed prosthodontics.