title: Prevention of bacterial leakage into and from prefabricated screw-retained crowns on implants in vitro.
abstract: Previous in vitro studies have shown that a mean gap of less than 4 microns between prefabricated crowns and implants of the Ha-Ti implant system is not a barrier to infiltration by Staphylococcus aureus. These studies confirmed earlier in vivo work showing that a multitude of oral microorganisms could colonize and infiltrate these gaps. In the present investigation, 30 Ha-Ti implant-crown assemblies were tested for bacterial leakage after the gaps were sealed with the chlorhexidine-containing varnish Cervitec. S. aureus leakage into the totally submerged test specimens was detected in 1 of 5 samples incubated for 4 weeks, while no leakage was detected in specimens incubated for 3, 5, 6, 7, and 8 weeks. When the sealed test specimens were partially submerged (that is, excluding the screw hole of the crown) and incubated for 3 to 11 weeks, none of the internal surfaces of the 30 test specimens manifested contamination. The clinical relevance of gap sealing in maintaining inflammation-free marginal mucosa and in achieving clinically successful treatment of peri-implantitis has yet to be determined.
authors.affiliation: Department of Prosthodontics, School of Dentistry, University of Basel, Switzerland.
authors.forename: C E
authors.initials: CE
authors.lastname: Besimo
authors.forename: J S
authors.initials: JS
authors.lastname: Guindy
authors.forename: D
authors.initials: D
authors.lastname: Lewetag
authors.forename: J
authors.initials: J
authors.lastname: Meyer
mesh_terms: D000891:Anti-Infective Agents, Local / Q000008:administration & dosage / Q000627:therapeutic use; D001672:Biocompatible Materials / Q000737:chemistry; D002710:Chlorhexidine / Q000008:administration & dosage / Q000627:therapeutic use; D003442:Crowns / Q000382:microbiology*; D015921:Dental Implants / Q000382:microbiology*; D019094:Dental Prosthesis, Implant-Supported / Q000382:microbiology*; D004338:Drug Combinations; D004866:Equipment Contamination / Q000517:prevention & control; D006801:Humans; D006882:Hydroxyapatites / Q000737:chemistry; D009055:Mouth / Q000382:microbiology; D010150:Paint; D010518:Periodontitis / Q000382:microbiology / Q000517:prevention & control; D013211:Staphylococcus aureus / Q000187:drug effects / Q000254:growth & development*; D013280:Stomatitis / Q000382:microbiology / Q000517:prevention & control; D013499:Surface Properties; D013943:Thymol / Q000008:administration & dosage / Q000627:therapeutic use; D014025:Titanium / Q000737:chemistry
chemical_list: D000891:Anti-Infective Agents, Local; D001672:Biocompatible Materials; D015921:Dental Implants; D004338:Drug Combinations; D006882:Hydroxyapatites; C079161:chlorhexidine, thymol drug combination; C098170:hydroxyapatite-titanium alloy; D013943:Thymol; D014025:Titanium; D002710:Chlorhexidine