title: In vivo early plaque formation on zirconia and feldspathic ceramic.
abstract: OBJECTIVE
  Zirconia is a ceramic material with optimal aesthetic and mechanical properties that make it adapt to esthetic recontructions in narrow spaces. Aim of this split mouth clinical trial is to compare amount and structure of early plaque coated to zirconia and feldspathic ceramic.
  
  
  METHODS
  Four patients were included in this study. A removable acrylic device was manufactured for each subject and equipped on the lingual surface in correspondence to molar teeth with eight specimens. Four zirconia samples were positioned on the right side (test) of the device, and 4 feldspathic ceramic samples were positioned on the left side (control). One test and one control samples were harvested from each device at 6, 12, 24 and 36 hours after oral environment exposition. A total of four samples for each group were collected at each timepoint; three of these were used for reverse transcription polymerase chain reaction analysis to evaluate the bacteria plaque amount; the remaining sample was used for scanning electron microscopy analysis to observe the bacteria plaque structure.
  
  
  RESULTS
  No significant differences were detected in terms of bacteria amount between test and control group at each timepoint. At scanning electron microscopy evaluation especially at 36 hou, bacteria plaque structure coated to zirconia surface appeared less uniform and compact compared to feldspathic ceramic.
  
  
  CONCLUSIONS
  Zirconia material may be considered adapt to prosthetic reconstructions that require high mechanical and aesthetic properties and that are exposed to the oral environment.
authors.affiliation: Unit of Prosthetic Dentistry, Dental Clinic, Department of Surgical Sciences, Reconstructive and DiagnosticUniversity of Milan, Fondazione IRCCS, Ospedale Maggiore Policlinico, Cá Granda, Milan, Italy. dino.re@unimi.it
authors.forename: D
authors.initials: D
authors.lastname: Re
authors.forename: G
authors.initials: G
authors.lastname: Pellegrini
authors.forename: P
authors.initials: P
authors.lastname: Francinetti
authors.forename: D
authors.initials: D
authors.lastname: Augusti
authors.forename: G
authors.initials: G
authors.lastname: Rasperini
mesh_terms: D000328:Adult; D000538:Aluminum Silicates; D001422:Bacterial Adhesion; D058491:Bacterial Load; D001672:Biocompatible Materials; D002516:Ceramics / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry; D003773:Dental Plaque / Q000382:microbiology / Q000648:ultrastructure; D003776:Dental Porcelain / Q000737:chemistry; D005260:Female; D006801:Humans; D008422:Materials Testing; D008854:Microscopy, Electron; D017680:Potassium Compounds; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012471:Salivary Proteins and Peptides / Q000032:analysis; D013499:Surface Properties; D055815:Young Adult; D015040:Zirconium
chemical_list: D000538:Aluminum Silicates; D001672:Biocompatible Materials; D003764:Dental Materials; D017680:Potassium Compounds; D012471:Salivary Proteins and Peptides; D003776:Dental Porcelain; C016447:feldspar; D015040:Zirconium; C028541:zirconium oxide