title: Flexible (Polyactive) versus rigid (hydroxyapatite) dental implants.
abstract: In a beagle dog study, the peri-implant bone changes around flexible (Polyactive) and rigid hydroxyapatite (HA) implants were investigated radiographically by quantitative digital subtraction analysis and by assessment of marginal bone height, with the aid of a computerized method. A loss of approximately 1 mm of marginal bone height was observed for both the dense Polyactive and the HA implants, after 6 months of loading. This value appeared to be stable from 12 weeks of loading onward. Along the total length of the implant during the first 6 weeks of loading, both the flexible (dense Polyactive) and the rigid (HA) implants showed a decrease in density. However, after this 6-week period, the bone density around the implants increased, and after 18 weeks the original bone density was reached. The flexible Polyactive implants provoked less decrease in density than the rigid HA implants, although not to a statistically significant level. This finding sustains the hypothesis that flexible implant materials may transfer stresses to the surrounding bone more favorably.
authors.affiliation: Department of Oral-Maxillofacial Surgery, Faculty of Medicine, University of Utrecht, The Netherlands.
authors.forename: G J
authors.initials: GJ
authors.lastname: Meijer
authors.forename: J
authors.initials: J
authors.lastname: Heethaar
authors.forename: M S
authors.initials: MS
authors.lastname: Cune
authors.forename: C
authors.initials: C
authors.lastname: De Putter
authors.forename: C A
authors.initials: CA
authors.lastname: Van Blitterswijk
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology; D000704:Analysis of Variance; D000818:Animals; D001672:Biocompatible Materials; D003758:Dental Implantation, Endosseous; D015921:Dental Implants / Q000009:adverse effects; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis; D004285:Dogs; D017886:Durapatite; D005260:Female; D008297:Male; D008334:Mandible; D016348:Osseointegration; D018583:Pliability; D011091:Polyesters; D011092:Polyethylene Glycols
chemical_list: D001672:Biocompatible Materials; D015921:Dental Implants; D011091:Polyesters; C072932:polyethylene oxide-polybutylene terephthalate copolymer; D011092:Polyethylene Glycols; D017886:Durapatite