Use this URL to cite or link to this record in EThOS:
Title: Peri-implantis : associated microbiota, biofilm formation and decontamination
Author: Hawas, Ahmed
ISNI:       0000 0004 5918 3366
Awarding Body: King's College London
Current Institution: King's College London (University of London)
Date of Award: 2014
Availability of Full Text:
Access from EThOS:
Access from Institution:
Peri-implantitis is a bacterially induced inflammatory condition that results in resorption of the bone supporting an implant. The methods for treating it are mainly empirical, and none have been shown to be universally successful. The first part of this research aimed to identify and compare the composition of the microbiota around dental implants with and without peri-implantitis. Subgingival plaque samples were collected from twenty-one subjects and samples were cultured using non-selective media and bacterial identification was carried out using 16S rRNA PCR. The second phase of the study investigated surface characteristics of implants that could influence the formation of a biofilm. Using a clinically relevant organism (Streptococcus oralis), an in vitro biofilm was developed and biofilm formation on four titanium implant surfaces exhibiting varying degrees of roughness with and without fluoride ions incorporated was evaluated using confocal laser scanning electron microscopy, bacterial culturing and scanning electron microscopy. The final phase examined the effects of mechanical debridement and air-polishing using glycine or 45S5 bioactive glass powders in re-establishing biocompatibility of the previously contaminated implant surfaces. Biocompatibility of the surfaces was tested using cell culture with alveolar human osteoblasts for cell viability, proliferation and cell differentiation. Results showed that a complex subgingival microbiota was found around dental implants. Peri-implantitis was associated with an increased bacterial load. Filifactor alocis, Streptococcus constellatus, Parvimonas micra and Actinomyces meyeri were significantly more prevalent in peri-implantitis, while Veillonella parvula/ dispar and Neisseria elongata were more prevalent in healthy sites. There were no significant differences in biofilm volume, surface area covered by the biofilm, nor number of bacteria found on any of the surfaces tested or at different levels within the biofilm suggesting that once colonization has been established, the effect of the surface diminishes with maturation of the biofilm. Although cleaning efficiency was different, all decontamination methods tested were shown to yield a biocompatible implant surface.
Supervisor: Palmer, Richard Michael Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available