title: Shock absorption capacity of restorative materials for dental implant prostheses: an in vitro study.
abstract: OBJECTIVE
  To measure the vertical occlusal forces transmitted through crowns made of different restorative materials onto simulated peri-implant bone.
  
  
  METHODS
  The study was conducted using a masticatory robot that is able to reproduce the mandibular movements and forces exerted during mastication. During robot mastication, the forces transmitted onto the simulated peri-implant bone were recorded using nine different restorative materials for the simulated single crown: zirconia, two glass-ceramics, a gold alloy, three composite resins, and two acrylic resins. Three identical sample crowns for each material were used. Each crown was placed under 100 masticatory cycles, occluding with the flat upper surface of the robot to evaluate the vertical forces transmitted. Two-way analysis of variance was used. Alpha was set at .05.
  
  
  RESULTS
  The statistical evaluation of the force peaks recorded on the vertical z-axis showed mean values of 641.8 N for zirconia; 484.5 N and 344.5 N, respectively, for the two glass-ceramics; 344.8 N for gold alloy; 293.6 N, 236 N, and 187.4 N, respectively, for the three composite resins; and 39.3 N and 28.3 N, respectively, for the two acrylic resins. Significant differences were found between materials (P < .0001), except for the comparison between gold alloy and one of the glass-ceramics.
  
  
  CONCLUSIONS
  Composite and above all acrylic resin crowns were more able to absorb shock from occlusal forces than crowns made of zirconia, ceramic material, or gold alloy.
authors.forename: Maria
authors.initials: M
authors.lastname: Menini
authors.forename: Enrico
authors.initials: E
authors.lastname: Conserva
authors.forename: Tiziano
authors.initials: T
authors.lastname: Tealdo
authors.forename: Marco
authors.initials: M
authors.lastname: Bevilacqua
authors.forename: Francesco
authors.initials: F
authors.lastname: Pera
authors.forename: Alessio
authors.initials: A
authors.lastname: Signori
authors.forename: Paolo
authors.initials: P
authors.lastname: Pera
mesh_terms: D000042:Absorption; D000180:Acrylic Resins / Q000737:chemistry; D000538:Aluminum Silicates / Q000737:chemistry; D001696:Biomechanical Phenomena; D001732:Bite Force; D002516:Ceramics / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003442:Crowns; D059605:Dental Implant-Abutment Design; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry*; D003776:Dental Porcelain / Q000737:chemistry; D019094:Dental Prosthesis, Implant-Supported; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D008409:Mastication / Q000502:physiology; D008422:Materials Testing; D053761:Nanocomposites / Q000737:chemistry; D013314:Stress, Mechanical; D015019:Yttrium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; D003188:Composite Resins; D015921:Dental Implants; D003764:Dental Materials; D006047:Gold Alloys; C493120:lithia disilicate; C499362:yttria stabilized tetragonal zirconia; D003776:Dental Porcelain; C078519:leucite; D015019:Yttrium; C023506:Glass ceramics; D015040:Zirconium; C028541:zirconium oxide