title: Implants placed in an irradiated dog mandible: a morphometric analysis.
abstract: The objective of this research was to evaluate the influence of radiotherapy on the osseointegration of oral implants in a canine model. After the extraction of all mandibular premolars and first and second molars, 11 male beagles were divided into 3 groups. The control group (3 dogs) received no radiation. The second group (4 dogs) was irradiated 4 weeks after implantation. The third group (4 dogs) was irradiated 8 weeks before implantation. Eight implants were placed in each dog, in an alternating pattern: 4 non-submerged ITI Bonefit titanium plasma spray-coated and 4 submerged Steri-Oss hydroxyapatite-coated. The irradiated dogs received 4.3 Gy daily for 10 days. After 6 months of osseointegration, the dogs were sacrificed and each hemimandible was dissected to isolate the implants. Quantification of the extent of the direct bone-implant contact was carried out by scanning electron microscopy backscattered electron images that reproduced each implant in its entirety, using a digitizing table connected to a computer. The results were expressed as a percentage of direct bone-implant contact versus total perimeter accessible to bone. The bone contact percentage for the control group was 87% for Steri-Oss implants and 69% for the ITI Bonefit implants; for the animals irradiated after implantation, the percentages were 82 for Steri-Oss implants and 58 for ITI Bonefit implants; and for the animals irradiated before implantation, the percentages were 62 for Steri-Oss implants and 28 for ITI Bonefit implants. A statistically significant difference appeared between the 2 types of implants (P < .001). A statistically significant difference was also seen between the 3 groups for both types of implants, except between the control group and the group irradiated after implantation (P = .14). This indicates that, overall, the timing of irradiation influences osseointegration. Osseointegration is possible before and after radiotherapy; however, the direct bone-implant contact increased when the implants were placed before irradiation.
authors.affiliation: Prosthodontics Department, Catholic University of Louvain, St. Luc University Hospital, Brussels, Belgium. Brogniez@prdt.ucl.ac.be
authors.forename: V
authors.initials: V
authors.lastname: Brogniez
authors.forename: W
authors.initials: W
authors.lastname: D'Hoore
authors.forename: V
authors.initials: V
authors.lastname: Grégoire
authors.forename: E
authors.initials: E
authors.lastname: Munting
authors.forename: H
authors.initials: H
authors.lastname: Reychler
mesh_terms: D000818:Animals; D020099:Coated Materials, Biocompatible; D016371:Cranial Irradiation / Q000009:adverse effects*; D003758:Dental Implantation, Endosseous / Q000379:methods; D015921:Dental Implants; D017267:Dental Prosthesis Design; D004285:Dogs; D008297:Male; D008334:Mandible / Q000528:radiation effects* / Q000601:surgery; D016348:Osseointegration / Q000528:radiation effects*; D013997:Time Factors
chemical_list: D020099:Coated Materials, Biocompatible; D015921:Dental Implants