title: Internal decontamination of dental implants: an in vivo randomized microbiologic 6-month trial on the effects of a chlorhexidine gel.
abstract: BACKGROUND
  Microbial penetration inside an implant's internal cavity results in a bacterial reservoir that has been associated with an area of inflamed connective tissue facing the fixture-abutment junction. The aim of the present clinical trial was to evaluate the effectiveness of a 1% chlorhexidine gel on the internal bacterial contamination of implants with screw-retained abutments.
  
  
  METHODS
  Thirty subjects (age range: 27.3 to 54.2 years) underwent single implant restoration. Three months after prosthodontic restoration, the modified sulcus bleeding index, modified plaque index, full-mouth plaque score, and full-mouth bleeding score were recorded. Microbiologic samples were also collected from the internal part of each fixture. Subjects were then divided into two equal groups: control and test groups (CG and TG, respectively). The CG had the abutment screwed and the crown cemented without any further intervention. Conversely, the TG had the internal part of the fixture filled with a 1% chlorhexidine gel before the abutment placement and screw tightening. Six months later, microbiologic and clinical procedures were repeated in both groups. Total bacterial count and multiplex polymerase chain analysis were performed to detect specific pathogens.
  
  
  RESULTS
  Clinical parameters remained stable throughout the study. From baseline to the 6-month examination, the total bacterial counts underwent a significant reduction in the TG (P<0.05). Detection of the single pathogen species did not show any significant differences. However, periopathogens were detected more frequently in the CG.
  
  
  CONCLUSIONS
  The application of a 1% chlorhexidine gel seemed to be an effective method to reduce bacterial colonization of the implant cavity over a 6-month period.
authors.affiliation: Department of Oral Science, University G. D'Annunzio, Chieti, Italy. mpaolantonio@unich.it
authors.forename: Michele
authors.initials: M
authors.lastname: Paolantonio
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Perinetti
authors.forename: Simonetta
authors.initials: S
authors.lastname: D'Ercole
authors.forename: Filippo
authors.initials: F
authors.lastname: Graziani
authors.forename: Giovanni
authors.initials: G
authors.lastname: Catamo
authors.forename: Gilberto
authors.initials: G
authors.lastname: Sammartino
authors.forename: Raffaele
authors.initials: R
authors.lastname: Piccolomini
mesh_terms: D000328:Adult; D001419:Bacteria / Q000145:classification; D002484:Cementation; D002710:Chlorhexidine / Q000008:administration & dosage / Q000627:therapeutic use*; D015169:Colony Count, Microbial; D003442:Crowns; D000044:Dental Abutments / Q000382:microbiology; D019551:Dental Disinfectants / Q000008:administration & dosage / Q000627:therapeutic use*; D019250:Dental Implants, Single-Tooth / Q000382:microbiology*; D003774:Dental Plaque Index; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D004203:Disinfection / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D005782:Gels; D005884:Gingival Hemorrhage / Q000145:classification; D006801:Humans; D008297:Male; D008875:Middle Aged; D010512:Periodontal Index; D016133:Polymerase Chain Reaction; D013499:Surface Properties
chemical_list: D019551:Dental Disinfectants; D005782:Gels; D002710:Chlorhexidine