Molecular analysis of microbiota associated with peri-implant diseases

Abstract

ObjectivesThe aim of this study was to identify bacteria associated with peri-implant diseases using Denaturing Gradient Gel Electrophoresis (DGGE) as a method for microbiological assessment. MethodsSubgingival plaque samples along with essential patient information and clinical indices were taken from 22 subjects showing signs of peri-implant diseases. Bacteria were detected from extracted DNA either by species specific PCR, or by using PCR coupled with DGGE and subsequent sequencing of resolved and excised bands. ResultsAltogether, approximately 26 different species were identified as components of peri-implant plaque, including non-culturable bacteria. Percentages of periodonto pathogenic bacterial species in plaque samples were: 82% of shallow pocket (<3mm), 51% of moderate pocket depth, and 63% of deep pocket (>7.5mm). A positive correlation was found between highly pathogenic bacteria and both Gingival Index score and pocket depth. ConclusionDGGE in combination with sequence analysis is a comprehensive and sensitive microbiological method for detection and identification of multiple bacterial species in peri-implant disease conditions. This makes it a valuable microbiological diagnostic method to help the clinician to conduct a more accurate clinical diagnosis and to plan appropriate treatment for peri-implant diseases.Based on results, Fusobacterium and Prevotella species were most prevalent in early stages of disease whilst an increased diversity of species was present during more advanced stages of disease.