Color Stability and Surface Roughness of Additive Manufactured versus Milled Interim Restorative Materials Using Two Surface Finish Protocols )An In Vitro Study)

Abstract

Summary The aim of this in vitro study was to compare the color stability and surface roughness of interim restorative materials fabricated using two techniques: milled and additive. Using two surface treatments: polishing and glazing. Two provisional resin restorative materials were used in the study, divided into two groups according to the method of construction: 3D Printing and Milling by CAD/CAM using two surface finishing Protocols. A total of 42 samples were fabricated; disc-shaped specimens of 10 mm in diameter and 2 mm in thickness were fabricated. Samples of each material were divided into two groups according to the technique of fabrication; (group M): milled (n = 21) and (group A): additive (n = 21) samples. Each group was divided into 3 subgroups according to the type of surface finishing:1-(Subgroup C) control subgroup: no surface finishing was done to the samples (n=7).2: (Subgroup P) polished subgroup: samples were polished using polishing paste (n = 7).3: (Subgroup G) glazed subgroup: samples were glazed using glaze material (n = 7). Specimens in (subgroup P) were polished using the Enhance finishing and polishing kit, finishing with carry out using aluminium oxide discs along with Prisma Gloss polishing paste. Specimens in (subgroup G) were finished using aluminium oxide discs and prepared with additional clear light-polymerizing protective coatings (Opti glaze). All samples were subjected to thermocycling for 5000 cycles between 5 ±2⁰ C and 55 ± 2⁰ C with a dwell time of 30 seconds in each bath and 20sec interval between baths at ambient air. Color measurements were obtained using a digital spectrophotometer