Clinical and Histologic Observations of Sites Implanted With Intraoral Autologous Bone Grafts or Allografts. 15 Human Case Reports

Abstract

The cases reported in this paper were treated at 7 different clinical centers and present clinical and histologic observations from 15 patients and 21 human biopsies. The biopsies were taken from extraction sockets or dental implant sites which were grafted with either autologous intra-oral bone (6 sites), demineralized freeze-dried bone (DFDBA) (7 sites), or mineralized freeze-dried bone (MFDBA) (7 sites), or a combination of autologous bone, DFDBA and a barrier membrane (1 site). Six sites were grafted with DFDBA and augmented with expanded polytetrafluoroethylene (ePTFE) barrier membranes. Biopsies for histological evaluation were taken 4 to 13 months after implantation. A bone scoring system of 0 to 4 was used to evaluate the sections for dead implanted particles or the presence of vital bone. A bone score of 3 indicated the presence of dead implant material, blood vessels, islands of cartilage, osteoblasts, and new bone formation. A score of 4 indicated total replacement of the implanted material by the host bone. The average bone score for sites which received autologous bone was 2.33; for DFDBA sites, 0.98; and MFDBA was 0.18. The over-riding histologic characteristic of sites implanted with DFDBA or MFDBA was retention of non-vital graft particles within fibrous connective tissue. Biopsies taken adjacent to the host bed demonstrated incorporation of the allografts (osteoconduction). Sites grafted with autologous bone chips also demonstrated non-vital bone chips surrounded by vital host bone (osteoconduction). Sites which received barrier membranes did not appear to improve or impair bone healing of the augmented sites. Autologous bone chips harvested from within the oral cavity as well as allografts may serve as biologic fillers, but do not apparently contribute to osteoinduction. Autologous bone will eventually be resorbed and replaced by the host. DFDBA and MFDBA are resorbed very slowly and apparently do not contribute to osteoinduction. Allografts apparently are not resorbed by osteoclasts and therefore their continued use around dental implants is questioned.

Avaliação histológica de hidroxiapatita sintética associada a fosfato de cálcio (?-TCP) utilizados em levantamento de assoalho de seio maxilar

“…Hematoxilina -Eosina, aumento original de 100. b -Fotomicroscopia, (Grupo EA) em maior aumento, ilustrando a presença de osteócitos viáveis (setas) nas trabéculas ósseas. Hematoxilina -Eosina, aumento original de 400. maxilar é tido como uma técnica cirúrgica segura, confiável e com excelentes índices de sucesso, comprovados por estudos com controles superiores a 10 anos [6][7][8] . Porém, devido à necessidade de um sítio doador e à sua morbidade, gradualmente outros biomateriais vêm sendo usados, apresentando índices de sucesso convincentes.…”

“…Essa conformação óssea, a partir do enxerto autógeno, também foi vista em outros estudos, como os de Becker et al 8 e Buser et al 12 . Além disso, as amostras de enxerto autógeno apresentaram tecido ósseo viável, não sendo possível distinguir com precisão as trabéculas neoformadas das partículas do enxerto com ósseo autógeno.…”

An experimental study of use of absorbable plate in combination with self-setting α-tricalcium phosphate for orthognathic surgery

“…22,23 Various types of biocompatible graft materials have been developed in consideration of bone regeneration and augumentation as well as further procedures such as dental implantation [24][25][26] . Autogenous bone graft has drawbacks such as the requirement of a second operation, which is sometimes accompanied by broad invasion, and a restricted source of materials.…”

A Preliminary Study on a Newly Developed Cell-hybridized Artificial Bone in a Beagle Dog: Bone Marrow Stromal Cells with an Interconnected Porous Hydroxyapatite Scaffold

“…[1][2][3] However, problems still exist including the limited volume of harvested bone available and complications at the donor site as a result of the necessary surgical procedure. 4,5 To overcome these problems and to obtain predictable bone grafting, other graft materials have been developed for use as bone substitutes.…”