title: Influence of Thermal Cycling on Flexural Properties and Simulated Wear of Computer-aided Design/Computer-aided Manufacturing Resin Composites.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the influence of thermal cycling on the flexural properties and simulated wear of computer-aided design/computer-aided manufacturing (CAD/CAM) resin composites.
  
  
  METHODS
  The six CAD/CAM resin composites used in this study were 1) Lava Ultimate CAD/CAM Restorative (LU); 2) Paradigm MZ100 (PM); 3) CERASMART (CS); 4) Shofu Block HC (SB); 5) KATANA AVENCIA Block (KA); and 6) VITA ENAMIC (VE). Specimens were divided randomly into two groups, one of which was stored in distilled water for 24 hours, and the other of which was subjected to 10,000 thermal cycles. For each material, 15 specimens from each group were used to determine the flexural strength and modulus according to ISO 6872, and 20 specimens from each group were used to examine wear using a localized wear simulation model. The test materials were subjected to a wear challenge of 400,000 cycles in a Leinfelder-Suzuki device (Alabama machine). The materials were placed in custom-cylinder stainless steel fixtures, and simulated localized wear was generated using a stainless steel ball bearing (r=2.387 mm) antagonist in a water slurry of polymethyl methacrylate beads. Simulated wear was determined using a noncontact profilometer (Proscan 2100) with Proscan and AnSur 3D software.
  
  
  RESULTS
  The two-way analysis of variance of flexural properties and simulated wear of CAD/CAM resin composites revealed that material type and thermal cycling had a significant influence (p<0.05), but there was no significant interaction (p>0.05) between the two factors. The flexural properties and maximum depth of wear facets of CAD/CAM resin composite were different (p<0.05) depending on the material, and their values were influenced (p>0.05) by thermal cycling, except in the case of VE. The volume losses in wear facets on LU, PM, and SB after 10,000 thermal cycles were significantly higher (p<0.05) than those after 24 hours of water storage, unlike CS, KA, and VE.
  
  
  CONCLUSIONS
  The results of this study indicate that the flexural properties and simulated wear of CAD/CAM resin composites are different depending on the material. In addition, the flexural properties and simulated wear of CAD/CAM resin composites are influenced by thermal cycling.
authors: A
authors: A
authors: Tsujimoto
authors: W W
authors: WW
authors: Barkmeier
authors: T
authors: T
authors: Takamizawa
authors: M A
authors: MA
authors: Latta
authors: M
authors: M
authors: Miyazaki
mesh_terms: D002516:Ceramics; D016722:Cermet Cements; D003188:Composite Resins / Q000737:chemistry*; D017076:Computer-Aided Design; D019554:Dental Restoration Wear; D055119:Elastic Modulus; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D015040:Zirconium
chemical_list: D016722:Cermet Cements; D003188:Composite Resins; C101939:Shofu High Dense; C000621297:VITA Enamic; C452079:paradigm MZ100; D015040:Zirconium