title: Pontic morphology as local risk factor in root decay and periodontal disease.
abstract: BACKGROUND
  In absence of treatment, old single edentulous spaces are subjected to progressively decrease in length due to tilting and rotation of the teeth situated mesial and distal. Lately when these spaces are prosthetically restored with a bridge and these teeth are becoming abutments, sanitizing of the prosthetic restoration is achieved with difficulty, the space between the pontic and the gingival surface becoming an area rich in pathogens that can cause various complications on the abutments.
  
  
  OBJECTIVE
  Considering these aspects, in this study we wanted to highlight the presence and the types of the microorganisms that can be found under the pontic even in an ideal situation, selecting only young adult patients with a good oral hygiene and only with metal-ceramic bridges.
  
  
  METHODS
  Determination of microorganisms was achieved by growing on BD Columbia Agar with 5% sheep blood. Incubation was done in anaerobe condition using GENbag system produced by BioMérieux Company.
  
  
  RESULTS
  The microorganisms that we determined were Streptococcus mutans, S. mitis, S. oralis, Gram-negative bacilli (Bacteroides ovatus, B. thetaiotaomicron) and Gram-positive bacilli (Bifidobacterium spp., Actinomyces israelii, Clostridium butyricum / beijerinckii) with relevance in the carious and periodontal disease.
  
  
  CONCLUSIONS
  In cases of single unit bridges with very narrow pontics, even in patients with a very good oral hygiene and metal-ceramic restorations, we can still find micro-organisms that can potentially generate decay or periodontal disease on the abutments, located in the gingival area underneath these pontics. These bacteria can have negative implications on the long-term prognosis of prosthetic restorations.
authors.affiliation: Department of Removable Prosthodontics, Faculty of Dentistry, "Carol Davila" University of Medicine and Pharmacy, Bucharest, Romania.
authors.forename: Magdalena Natalia
authors.initials: MN
authors.lastname: Dina
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Mărgărit
authors.forename: Oana Cella
authors.initials: OC
authors.lastname: Andrei
mesh_terms: D000328:Adult; D003731:Dental Caries / Q000382:microbiology*; D003773:Dental Plaque / Q000382:microbiology*; D003779:Denture Design / Q000009:adverse effects*; D003830:Denture, Partial, Fixed / Q000009:adverse effects* / Q000382:microbiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010510:Periodontal Diseases / Q000382:microbiology*; D012307:Risk Factors; D014092:Tooth Root / Q000382:microbiology*; D055815:Young Adult