title: Impact fracture resistance of two titanium-abutment systems versus a single-piece ceramic implant.
abstract: BACKGROUND
  The number of patients with oral implants has increased significantly. However, the literature addressing the effect of impact force on titanium and/or ceramic implants is inconclusive. This study sought to determine the fracture resistance to impact load of titanium and ceramic endosseous oral implants.
  
  
  METHODS
  Endosseous oral implants were vertically positioned in two different mounting media: brass and a bone-simulation material. The implant configurations tested included an experimental one-piece Y-TZP implant and a commercially available titanium implant (external hex) with both titanium and zirconia abutments. The specimens were subjected to an impact load using a pendulum impact tester with tup weights varying from 0.9 to 4.5 kg delivered at a radius of 40.64 mm. Loads were delivered to the abutment at a point 4.27 mm above the implant fixture and block junction. Statistical differences (p < .05) were established using the F-test for variances and, when different, t-test assuming unequal variances.
  
  
  RESULTS
  For implants clamped in brass, the titanium implant with titanium abutment required the greatest energy to fracture the implant-abutment system (only the abutment screw failed). The ceramic implant and ceramic abutment on titanium implant presented the lowest fracture energy (p < .01). No significant differences were observed when different systems were inserted into the foam blocks of the bone substitute (p > .25).
  
  
  CONCLUSIONS
  This investigation showed that the fracture energy of two titanium-abutment systems versus a single-piece Y-TZP implant in foam blocks simulating bone elastic modulus was not different, and that differences occurred when the embedding material elastic modulus was increased an order of magnitude.
authors.affiliation: New York University College of Dentistry, New York, NY 10010, USA.
authors.forename: Nelson R F A
authors.initials: NR
authors.lastname: Silva
authors.forename: Pedram
authors.initials: P
authors.lastname: Nourian
authors.forename: Paulo G
authors.initials: PG
authors.lastname: Coelho
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Rekow
authors.forename: Van P
authors.initials: VP
authors.lastname: Thompson
mesh_terms: D000465:Algorithms; D000497:Alloys / Q000737:chemistry; D018786:Bone Substitutes / Q000737:chemistry; D002516:Ceramics / Q000737:chemistry*; D003300:Copper / Q000737:chemistry; D000044:Dental Abutments; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis / Q000295:instrumentation; D055119:Elastic Modulus; D006801:Humans; D008422:Materials Testing; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry*; D015019:Yttrium / Q000737:chemistry; D015032:Zinc / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D000497:Alloys; D018786:Bone Substitutes; D003764:Dental Materials; C499362:yttria stabilized tetragonal zirconia; C048399:brass; D015019:Yttrium; D003300:Copper; D015040:Zirconium; D014025:Titanium; D015032:Zinc; C028541:zirconium oxide