title: Healing of implant dehiscence defects with and without expanded polytetrafluoroethylene membranes: a controlled clinical and histological study.
abstract: Bone augmentation around implant fixtures using the technique of guided tissue regeneration has been described in a number of reports. The aim of this study was to evaluate bone fill around dehiscence defects at matched defects randomly allocated to test (expanded polytetrafluoroethylene; Gore-Tex) or control treatments within the same patient. Six edentulous subjects were treated with overdentures supported by 2 fixtures ad modum Bränemark. In addition, 2 experimental 7-mm fixtures with nearly identical dehiscence defects on the labial aspect were placed in the anterior part of the mandible. Baseline defect heights ranged from 2.5 to 4.0 mm with 2 to 4 threads exposed. The test fixture dehiscence was covered with a Gore-Tex membrane secured with a cover screw. The experimental fixtures were exposed after 5 months at stage 2 surgery and measurements and photographs repeated. The fixtures were then removed with a trephine and processed for histological evaluation. Regeneration of a hard tissue resembling bone was observed in 4 of 6 cases treated with Gore-Tex, amounting to between 95 and 100% elimination of the dehiscence and total coverage of the threads. However, in one of these cases, histological evaluation showed that it was soft tissue and not bone, and in a further case soft tissue regeneration was apparent both clinically and histologically. In another case there was no significant regeneration at either test or control defects. Although there was a trend for the Gore-Tex-treated dehiscences to respond more favourably, the differences in clinical and histological measurements between test and control failed to reach statistical significance.
authors.affiliation: Department of Periodontology, United Medical School, Guy's Hospital, London, United Kingdom.
authors.forename: R M
authors.initials: RM
authors.lastname: Palmer
authors.forename: P D
authors.initials: PD
authors.lastname: Floyd
authors.forename: P J
authors.initials: PJ
authors.lastname: Palmer
authors.forename: B J
authors.initials: BJ
authors.lastname: Smith
authors.forename: C B
authors.initials: CB
authors.lastname: Johansson
authors.forename: T
authors.initials: T
authors.lastname: Albrektsson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001861:Bone Regeneration; D015921:Dental Implants / Q000009:adverse effects*; D005260:Female; D016557:Guided Tissue Regeneration, Periodontal; D006801:Humans; D008297:Male; D008334:Mandible / Q000601:surgery; D008567:Membranes, Artificial; D008875:Middle Aged; D016348:Osseointegration; D011138:Polytetrafluoroethylene; D018709:Statistics, Nonparametric; D013529:Surgical Wound Dehiscence / Q000601:surgery*; D014945:Wound Healing
chemical_list: D015921:Dental Implants; D008567:Membranes, Artificial; D011138:Polytetrafluoroethylene