title: Chemically modified titanium-zirconium implants in comparison with commercially pure titanium controls stimulate the early molecular pathways of bone healing.
abstract: OBJECTIVE
  Titanium-zirconium (TiZr) has been proposed as a mechanically stronger alternative to commercially pure titanium for oral and orthopaedic implants. However, not much is known on the osseointegration kinetics of TiZr surfaces. In this study, we aimed to identify the genetic response of bone around TiZr implants compared to pure Ti.
  
  
  METHODS
  Microtextured and hydrophilic TiZr implants (tests) and cpTi implants grade IV (controls) were placed in the tibia of 30 New Zealand white rabbits. At 2, 4 and 12 weeks, the implants were subjected to removal torque test (RTQ). The expression of a panel of genes involved in the process of osseointegration was measured in the bone around the test and control implants by means of quantitative real-time polymerase chain reaction (PCR) and compared to the control samples.
  
  
  RESULTS
  The controls yielded statistically significant higher RTQ at 4 weeks, but the RTQ of the tests had a larger increase between 4 and 12 weeks, when both groups reached similar values. The gene expression analysis showed that all selected markers for bone formation, bone remodelling and cytokines were significantly upregulated around TiZr implants after 2 weeks. After 4 weeks of healing, two bone formation markers were significantly more expressed in the test samples, while at 12 weeks, the expression of all genes was similar in the two groups.
  
  
  CONCLUSIONS
  TiZr implants showed comparable biomechanical outcomes to cpTi up to 12 weeks of healing. However, at early healing stages, they showed a significant upregulation of osteogenesis and osteoclastogenesis markers.
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Silvia
authors.initials: S
authors.lastname: Galli
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.|Department of Oral and Maxillofacial Surgery and Oral Medicine, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Ryo
authors.initials: R
authors.lastname: Jimbo
authors.affiliation: Oral Implant Center, Tokushima University Hospital, Tokushima, Japan.
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Naito
authors.affiliation: Institut Straumann AG, Basel, Switzerland.
authors.forename: Simon
authors.initials: S
authors.lastname: Berner
authors.affiliation: Institut Straumann AG, Basel, Switzerland.|College of Dentistry, New York University, New York, NY, USA.
authors.forename: Michel
authors.initials: M
authors.lastname: Dard
authors.affiliation: Department of Prosthodontics, Faculty of Odontology, Malmö University, Malmö, Sweden.
authors.forename: Ann
authors.initials: A
authors.lastname: Wennerberg
mesh_terms: D000818:Animals; D015921:Dental Implants; D017267:Dental Prosthesis Design; D005260:Female; D008422:Materials Testing; D016348:Osseointegration / Q000502:physiology*; D011817:Rabbits; D015398:Signal Transduction; D013997:Time Factors; D014025:Titanium / Q000737:chemistry; D015040:Zirconium / Q000737:chemistry
chemical_list: D015921:Dental Implants; D015040:Zirconium; D014025:Titanium
keywords: Ti alloys; Ti-Zr; gene expression; osseointegration