Bone Density around Titanium Dental Implants Coating Tested/Coated with Chitosan or Melatonin: An Evaluation via Microtomography in Jaws of Beagle Dogs

Peri-implant bone density plays an important role in the osseointegration of dental implants. The aim of the study was to evaluate via micro-CT, in Hounsfield units, the bone density around dental implants coated with chitosan and melatonin and to compare it with the bone density around implants with a conventional etched surface after 12 weeks of immediate post-extraction placement in the jaws of Beagle dogs. Six dogs were used, and 48 implants were randomly placed: three groups-melatonin, chitosan, and control. Seven 10 mm x 10 mm regions of interest were defined in each implant (2 in the crestal zone, 4 in the medial zone, and 1 in the apical zone). A total of 336 sites were studied with the AMIDE tool, using the Norton and Gamble classification to assess bone density. The effect on bone density of surface coating variables (chitosan, melatonin, and control) at the crestal, medial, and apical sites and the implant positions (P2, P3, P4, and M1) was analyzed at bivariate and multivariate levels (linear regression). Adjusted effects on bone density did not indicate statistical significance for surface coatings (p = 0.653) but did for different levels of ROIs (p < 0.001) and for positions of the implants (p = 0.032). Micro-CT, with appropriate software, proved to be a powerful tool for measuring osseointegration.