title: Light and laser scanning microscopy analysis of hydroxyapatite used in periodontal osseous defects in man: evidence of a different resorption pattern in bone and soft tissues.
abstract: Hydroxyapatite (HA) is a highly biocompatible material that recently has been shown to undergo biodegradation. The mechanisms of this phenomenon are unclear, and humoral and cellular events have been thought to be implicated. In the present study HA particles were put into infraosseous defects on teeth that were to be extracted for prosthetic reasons and then retrieved after a 1-year period. The specimens were processed with the cutting grinding system. Results show a very sharp difference of the biodegradation processes, related to the tissues that surround the HA particles. HA in tight contact with mineralized bone showed no evidence of degradation or resorption, while on the contrary, in the areas where bone loose connective tissue was present, it was possible to observe HA crystals detached and scattered in cells cytoplasm or extracellular fluids. This dissolution and resorption phenomenon were observed also by Laser Scanning Microscope (LSM) in fluorescent mode. These differences in degrees of degradation between bone and loose connective tissue could be due to the small amount of interstitial fluid present in mineralized bone and the greater flow of fluid through connective tissue.
authors.affiliation: Dental School, University of Chieti, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Piattelli
authors.forename: C
authors.initials: C
authors.lastname: Mangano
authors.forename: R
authors.initials: R
authors.lastname: Donzelli
authors.forename: N
authors.initials: N
authors.lastname: Romasco
authors.forename: P
authors.initials: P
authors.lastname: Trisi
mesh_terms: D001673:Biodegradation, Environmental; D001862:Bone Resorption / Q000378:metabolism*; D001842:Bone and Bones / Q000378:metabolism*; D003758:Dental Implantation, Endosseous; D006801:Humans; D006882:Hydroxyapatites / Q000493:pharmacokinetics*; D007834:Lasers; D008856:Microscopy, Fluorescence; D010514:Periodontal Pocket / Q000378:metabolism* / Q000628:therapy; D010519:Periodontium / Q000378:metabolism*
chemical_list: D006882:Hydroxyapatites