Evaluation of the Effect of Different Construction Techniques on Removable Partial Denture Frameworks: Conventional Wax Pattern,3D Printing Resin, and Metal 3D Printing ( Comparative Vitro Study )

Background: Nowadays different construction techniques of removable partial denture farmwork are used to improve RPD frameworks by improving their mechanical and biological properties. The manual wax pattern technique is a multiple-step process while the 3D resin RPD framework is another construction technique produced from a virtual design created from Digital CDA software which will be invested and cast into a Co–Cr framework. Subtractive manufacturing and additive manufacturing are CAD systems that produce metal 3D printing frameworks.Material and Method: Twenty-one designed cast models were divided into three groups based on the construction techniques used for the removable partial denture framework Group I: Seven frameworks fabricated using the conventional wax pattern technique Group II: Seven frameworks fabricated using the 3D printing castable resin techniqueGroup III: Seven frameworks fabricated using the metal 3D printing technique. The rest fit accuracy was compared between the three groups by calculating the thickness of the silicone adapted between the rest and the corresponding rest seatusing a Digital microscope Result: there was a statistically significant difference between Group III and both Group I and II while there was a statistically non-significant difference between Group I and IIKeywords: Rest, Accuracy, Technique, Fit, Rest seat.Conclusion: Group III showed the best rest fit accuracy between the rest and its corresponding rest seat when compared with Group I and Group II while Group I showed slightly better rest fit accuracy than Group II but this difference was insignificant