title: Incidence of undetected cement on CAD/CAM monolithic zirconia crowns and customized CAD/CAM implant abutments. A prospective case series.
abstract: OBJECTIVE
  The aim of this study was to assess the frequency of cement residues after cementation of CAD/CAM monolithic zirconia crowns on customized CAD/CAM titanium abutments.
  
  
  METHODS
  Sixty premolars and molars were restored on Astra Tech Osseospeed TX™implants using single monolithic zirconia crowns fixed on two types of custom-made abutments: Atlantis™titanium or Atlantis™Gold Hue. Occlusal openings providing access to the abutment screws were designed for retrievability of the crown/abutment connection. After fixation with glass ionomer cement, the crown/abutment units were unscrewed to evaluate the presence of residual cement. Dichotomous assessment of the presence or absence of cement at the crown/abutment unit and peri-implant tissues was performed.
  
  
  RESULTS
  Clinically undetected cement excess was visible on 44 of 60 restorations (73.3%). There was no interdependency between residual cement presence and implant location or diameter. However, a dependency between the presence of residual cement and the aspect of the abutment/crown connection could be noted. The majority of the residues were observed on the distal (17.9%) and mesial (15%) aspects. While on the palatal/lingual aspect, the cement was visible in 8.8%; only 3.4% of all surfaces displayed cement residues.
  
  
  CONCLUSIONS
  Within the limitations of the study, it can be concluded that the use of customized CAD/CAM abutments do not guarantee avoidance of subgingival cement residues after crown cementation.
authors.affiliation: Dental - Medical Clinic MED-ORAL, Rumia, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Wasiluk
authors.affiliation: Dental - Medical Clinic MED-ORAL, Rumia, Poland.|Department of Prosthetic Dentistry, Medical University of Gdańsk, Gdańsk, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Chomik
authors.affiliation: Private Practice, Ludwigshafen, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Gehrke
authors.affiliation: Dental Practice, Białystok, Poland.|Department of Periodontal and Oral Mucosa Diseases Medical University of Białystok, Białystok, Poland.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Pietruska
authors.affiliation: Dental Practice, Białystok, Poland.|Department of Periodontal and Oral Mucosa Diseases Medical University of Białystok, Białystok, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Skurska
authors.affiliation: Dental Practice, Białystok, Poland.
authors.forename: Jan
authors.initials: J
authors.lastname: Pietruski
mesh_terms: D001641:Bicuspid; D017076:Computer-Aided Design; D003442:Crowns; D000044:Dental Abutments; D003738:Dental Cements; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention / Q000379:methods*; D005260:Female; D005899:Glass Ionomer Cements / Q000737:chemistry; D006801:Humans; D008297:Male; D008875:Middle Aged; D008963:Molar; D011446:Prospective Studies; D014025:Titanium; D015040:Zirconium
chemical_list: D003738:Dental Cements; D005899:Glass Ionomer Cements; D015040:Zirconium; D014025:Titanium; C028541:zirconium oxide
keywords: CAD/CAM implant abutments; cement; zirconia crowns