title: Comparative in vitro evaluation of CAD/CAM vs conventional provisional crowns.
abstract: OBJECTIVE
  This study compared the marginal gap, internal fit, fracture strength, and mode of fracture of CAD/CAM provisional crowns with that of direct provisional crowns.
  
  
  METHODS
  An upper right first premolar phantom tooth was prepared for full ceramic crown following tooth preparation guidelines. The materials tested were: VITA CAD-Temp®, Polyetheretherketone "PEEK", Telio CAD-Temp, and Protemp™4 (control group). The crowns were divided into four groups (n=10), Group1: VITA CAD-Temp®, Group 2: PEEK, Group 3: Telio CAD-Temp, and Group 4: Protemp™4. Each crown was investigated for marginal and internal fit, fracture strength, and mode of fracture. Statistical analysis was performed using GraphPad Prism software version 6.0.
  
  
  RESULTS
  The average marginal gap was: VITA CAD-Temp® 60.61 (±9.99) µm, PEEK 46.75 (±8.26) µm, Telio CAD-Temp 56.10 (±5.65) µm, and Protemp™4 193.07(±35.96) µm (P<0.001). The average internal fit was: VITA CAD-Temp® 124.94 (±22.96) µm, PEEK 113.14 (±23.55) µm, Telio CAD-Temp 110.95 (±11.64) µm, and Protemp™4 143.48(±26.74) µm. The average fracture strength was: VITA CAD-Temp® 361.01 (±21.61) N, PEEK 802.23 (±111.29) N, Telio CAD-Temp 719.24 (±95.17) N, and Protemp™4 416.40 (±69.14) N. One-way ANOVA test showed a statistically significant difference for marginal gap, internal gap, and fracture strength between all groups (p<0.001). However, the mode of fracture showed no differences between the groups (p>0.05).
  
  
  CONCLUSIONS
  CAD/CAM fabricated provisional crowns demonstrated superior fit and better strength than direct provisional crowns.
authors.affiliation: - Erbil Polytechnic University, Department of Dental Prevention, Erbil, Kurdistan Region, Iraq.
authors.forename: Adil Othman
authors.initials: AO
authors.lastname: Abdullah
authors.affiliation: - Aristotle University of Thessaloniki, Department of Operative Dentistry, School of Dentistry, Thessaloniki, Greece.
authors.forename: Effrosyni A
authors.initials: EA
authors.lastname: Tsitrou
authors.affiliation: - University of Sheffield, School of Clinical Dentistry, Academic Unit of Restorative Dentistry, Sheffield, United Kingdom.
authors.forename: Sarah
authors.initials: S
authors.lastname: Pollington
mesh_terms: D000180:Acrylic Resins; D000704:Analysis of Variance; D001577:Benzophenones; D003188:Composite Resins; D017076:Computer-Aided Design; D003442:Crowns; D018772:Dental Marginal Adaptation; D017267:Dental Prosthesis Design / Q000379:methods*; D019232:Dental Restoration Failure; D007659:Ketones; D008422:Materials Testing; D011092:Polyethylene Glycols; D011108:Polymers; D012016:Reference Values; D015203:Reproducibility of Results; D018709:Statistics, Nonparametric; D014082:Tooth Fractures
chemical_list: D000180:Acrylic Resins; D001577:Benzophenones; D003188:Composite Resins; D007659:Ketones; D011108:Polymers; C520134:VITA CAD-Temp; C063834:polyetheretherketone; D011092:Polyethylene Glycols; C069714:Protemp