Comparative Assessment of Polymerization Techniques on the Fit Accuracy of Acrylic Resins Fabricated by CAD-CAM Milling, 3D Printing, and Microwave Processing

Aims: Poly-methyl-methacrylate resin has been used commonly for denture bases. Polymerization shrinkageand release of thermal stresses are the major disadvantages exhibited of these materials Till date, no researchis there in literature comparing the adaptation accuracy microwave acrylic resin cured by microwave energyand resin cured by CAD-CAM milling and 3D Printed technique The present study was conducted to checkthe effect of curing mode on the adaptation accuracy of CAD-CAM Milled, 3D Printed and microwaveprocessed acrylic resin.Materials and Method: A master cast was duplicated to obtain 36 gypsum casts. In the computer-aideddesign and computer-aided manufacturing (CAD/CAM) groups (milling and 3-D printing), the 24 gypsumcasts from two groups were scanned. An STL file was obtained and a master complete denture base wasdesigned and then fabricated according to each technique . In the conventional group, a polyvinyl siloxaneputty Mold was obtained from the milled complete denture base, and this Mold was used to fabricate 12microwave processed acrylic resin by microwave energy The base/cast sets were sectioned transversally in theposterior palatal seal zone. The measurements were made at the right marginal limit, left marginal limit, rightridge crest, left ridge crest and the palatal midline. The existence of gaps between the casts and acrylic wasassessed using a stereomicroscope.Results: The mean marginal discrepancy at Right marginal limit, left marginal limit, Right Ridge crest, LeftRidge crest and Palatal midline was significantly more in microwave resin samples cured by microwaveenergy (500 W for 3 min) in comparison to resin samples cured by CAD- CAM 3D Printed Technique. Themean marginal discrepancy at, right marginal limit, left marginal limit, Right Ridge crest, Left Ridge crest andPalatal midline was significantly more in microwave resin samples cured by microwave energy (500 W for 3min) in comparison to resin samples cured by CAD–CAM milling Technique.There was no significant difference at, right marginal limit, left marginal limit, Right Ridge crest, Left Ridgecrest and Palatal midline of dimensional discrepancy between resin samples cured by either CAD-CAMmilling or 3D Printed technique.Conclusion: It is evident that resin denture base produced by CAD-CAM milling or 3D Printed techniqueproduced the minimal adaptation discrepancy.Clinical Significance: CAD-CAM milling or 3D Printing technique can be adopted for fabrication of thecomplete denture bases.