title: Biological Evaluation of Implant Drill Made from Zirconium Dioxide.
abstract: OBJECTIVE
  Zirconia is a good candidate material in the dental field. In this study, we evaluated biological responses against a zirconia drill using a bone cavity healing model.
  
  
  METHODS
  Zirconia drills, stainless steel drills, and the drilled bone surface were observed by scanning electron microscopy (SEM), before and after cavity preparation. For the bone cavity healing model, the upper first and second molars of Wistar rats were extracted. After 4 weeks, cavities were prepared with zirconia drills on the left side. As a control, a stainless steel drill was used on the right side. At 3, 7, and 14 days after surgery, micro-CT images were taken. Samples were prepared for histological staining.
  
  
  RESULTS
  SEM images revealed that zirconia drills maintained sharpness even after 30 drilling procedures. The bone surface was smoother with the zirconia drill. Micro-CT images showed faster and earlier bone healing in the zirconia drill cavity. On H-E staining, at 7 days, the zirconia drill defect had a smaller blank lacunae area. At 14 days, the zirconia drill defect was filled with newly formed bone.
  
  
  CONCLUSIONS
  The zirconia drill induces less damage during cavity preparation and is advantageous for bone healing. (197 words).
authors.affiliation: Division of Bio-prosthodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Akiba
authors.affiliation: Division of Bio-prosthodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Eguchi
authors.affiliation: Division of Bio-prosthodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Nami
authors.initials: N
authors.lastname: Akiba
authors.affiliation: Division of Bio-prosthodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.
authors.forename: Katsumi
authors.initials: K
authors.lastname: Uoshima
mesh_terms: D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D003754:Dental High-Speed Equipment; D003758:Dental Implantation, Endosseous / Q000295:instrumentation*; D003786:Dental Pulp Cavity / Q000502:physiology*; D008297:Male; D008437:Maxilla / Q000000981:diagnostic imaging / Q000502:physiology; D008855:Microscopy, Electron, Scanning; D023421:Models, Animal; D017208:Rats, Wistar; D013499:Surface Properties; D055114:X-Ray Microtomography; D015040:Zirconium
chemical_list: D015040:Zirconium; C028541:zirconium oxide
keywords: bone defect healing; dental implant; osseointegration; zirconium dioxide