Effects of Cervical Design and Cement Choice on Fracture Resistance of 3D Printed Permanent Crowns
Yigit Ömur
Visitor Researcher in Turku University, pHd student in Ege University
Objectives
3D printed resin materials have recently emerged in the market, offering a wide range of applications from short-term temporary solutions to permanent crown applications. This study aims to evaluate the effect of different cervical finish line (CFL) designs on the fracture resistance of 3D printed full crown restorations, using various luting agents for cementation.
Materials and Methods
Thirty-six extracted premolar teeth were randomly divided into three groups according to CFL 1) Chamfer [C], 2) Rounded shoulder [S] and 3) Knife edge [K] (n=12). Crowns with identical occlusal surfaces were designed with ExoCAD version 3.1. Crowns were printed using printable resin material (Varseo Smile Crown Plus; Bego GmbH) using a DLP 3D Printer (VarseoXS; Bego GmbH) and post cured according to the manufacturer’s instructions. Specimens were cemented with either a glass ionomer cement (Aqua Meron; Voco GmbH) [G] or a self-adhesive resin cement (G-Cem One, GC International) [A]. Specimens were stored in artificial saliva for 72 hours at 37°C in a dark environment. Mechanical testing was conducted using a universal testing machine (AGS-X. Shimadzu) under compression loading. using a 4 mm diameter stainless steel ball at the center of occlusal fossa of 3D-printed crowns at a crosshead speed of 1 mm/min until failure. Fracture resistance (N) of the specimens were recorded. The fracture types were also analyzed. Data were analyzed using one-way ANOVA. (α= 0.05)
Results
The mean (±SD)fracture resistance ranged from 931N(±105) for KA group to 673 N (±202)for CG group. No statistical differences were found between cervical finish line (P=0,197) and the cement type (P=0,062)
Conclusions
Within the constraints of this study's methodology and testing parameters, it noted that neither the finish line design nor the type of cement significantly affected the fracture resistance of 3D printed crowns.