title: Dental implant bioactive surface modifications and their effects on osseointegration: a review.
abstract: BACKGROUND
  The purpose of this article is to review and update the current developments of biologically active dental implant surfaces and their effect on osseointegration.
  
  
  METHODS
  PubMed was searched for entries from January 2006 to January 2016. Only in-vivo studies that evaluated the effects of biomolecular coatings on titanium dental implants inserted into the bone of animals or humans were included.
  
  
  RESULTS
  Thirty four non-review studies provided data and observations were included in this review. Within the criteria, four categories of biomolecular coatings were evaluated. The potential biomolecules include bone morphogenetic proteins in 8 articles, other growth factors in 8 articles, peptides in 5 articles, and extracellular matrix in 13 articles. Most articles had a healing period of 1 to 3 months and the longest time of study was 6 months. In addition, all studies comprised of implants inserted in animals except for one, which evaluated implants placed in both animals and humans. The results indicate that dental implant surface modification with biological molecules seem to improve performance as demonstrated by histomorphometric analysis (such as percentage of bone-to-implant contact and peri-implant bone density) and biomechanical testing (such as removal torque, push-out/pull-out tests, and resonance frequency analysis).
  
  
  CONCLUSIONS
  Bioactive surface modifications on implant surfaces do not always offer a beneficial effect on osseointegration. Nevertheless, surface modifications of titanium dental implants with biomolecular coatings seem to promote peri-implant bone formation, resulting in enhanced osseointegration during the early stages of healing. However, long-term clinical studies are needed to validate this result. In addition, clinicians must keep in mind that results from animal experiments need not necessarily reflect the human clinical reality.
authors.affiliation: Department of Periodontics, University of Texas School of Dentistry at Houston, Houston, TX USA.
authors.forename: Hsiu-Wan
authors.initials: HW
authors.lastname: Meng
authors.affiliation: College of Dentistry, The Ohio State University, Columbus, OH USA.
authors.forename: Esther Yun
authors.initials: EY
authors.lastname: Chien
authors.affiliation: Division of Periodontology, College of Dentistry, The Ohio State University, 305 West 12th Avenue, Columbus, OH 43210 USA.
authors.forename: Hua-Hong
authors.initials: HH
authors.lastname: Chien
keywords: Bioactive surface modification; Dental implant; Osseointegration