title: Biological performance of chemical hydroxyapatite coating associated with implant surface modification by laser beam: biomechanical study in rabbit tibias.
abstract: OBJECTIVE
  Considering the potential of the association between laser ablation and smaller scale hydroxyapatite (HA) coatings to create a stable and bioactive surface on titanium dental implants, the aim of the present study was to determine, by the removal torque test, the effects of a surface treatment created by laser-ablation (Nd:YAG) and, later, thin deposition of HA particles by a chemical process, compared to implants with only laser-ablation and implants with machined surfaces.
  
  
  METHODS
  Forty-eight rabbits received 1 implant by tibia of the following surfaces: machined surface (MS), laser-modified surface (LMS), and biomimetic hydroxiapatite coated surface (HA). After 4, 8, and 12 weeks of healing, the removal torque was measured by a torque gauge. The surfaces studied were analyzed according to their topography, chemical composition, and roughness.
  
  
  RESULTS
  Average removal torque in each period was 23.28, 24.0, and 33.85 Ncm to MS, 33.0, 39.87, and 54.57 Ncm to LMS, and 55.42, 63.71 and 64.0 Ncm to HA. The difference was statistically significant (P < .05) between the LMS-MS and HA-MS surfaces in all periods of evaluation, and between LMS-HA to 4 and 8 weeks of healing. The surface characterization showed a deep, rough, and regular topography provided by the laser conditioning, that was followed by the HA coating.
  
  
  CONCLUSIONS
  Based on these results, it was possible to conclude that the implants with laser surface modification associated with HA biomimetic coating can shorten the implant healing period by the increase of bone implant interaction during the first 2 months after implant placement.
authors.affiliation: Department of Periodontology, School of Dentistry, UNESP, São Paulo State University, Araraquara, São Paulo, Brazil. rafaelsfaeda@foar.unesp.br
authors.forename: Rafael S
authors.initials: RS
authors.lastname: Faeda
authors.forename: Hewerson S
authors.initials: HS
authors.lastname: Tavares
authors.forename: Rafael
authors.initials: R
authors.lastname: Sartori
authors.forename: Antonio C
authors.initials: AC
authors.lastname: Guastaldi
authors.forename: Elcio
authors.initials: E
authors.lastname: Marcantonio
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D040761:Biomimetic Materials / Q000737:chemistry; D002130:Calcium Phosphates / Q000032:analysis; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D015921:Dental Implants; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D017886:Durapatite / Q000737:chemistry*; D004577:Electron Probe Microanalysis; D006358:Hot Temperature; D053844:Lasers, Solid-State; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D016348:Osseointegration / Q000502:physiology; D011817:Rabbits; D013314:Stress, Mechanical; D013499:Surface Properties; D013977:Tibia / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D014025:Titanium / Q000737:chemistry*; D019415:Torque; D014945:Wound Healing / Q000502:physiology
chemical_list: D002130:Calcium Phosphates; D020099:Coated Materials, Biocompatible; D015921:Dental Implants; D003764:Dental Materials; D017886:Durapatite; D014025:Titanium