title: The influence of intracrevicular crown margins on gingival health: preliminary findings.
abstract: BACKGROUND
  The effect on gingival tissue of various crown materials in combination with different abutment biomaterials should be investigated.
  
  
  OBJECTIVE
  This in vivo study determined the gingival health and subgingival levels of periodontal inflammation-associated bacteria adjacent to various crown and abutment material combinations.
  
  
  METHODS
  . Patients in the study received 1 of 5 treatments: an all-ceramic crown luted to a natural tooth, a metal-ceramic (titanium) crown luted to natural tooth, a metal-ceramic (high noble alloy) crown luted to natural tooth, an all-ceramic crown luted to a titanium implant abutment, or a metal-ceramic (high noble alloy) crown luted to a titanium implant abutment. Plaque was collected at least 6 months after luting by paper point from the gingival sulcus of each crown and an adjacent unrestored (control) tooth. DNA probe analysis was performed to determine the levels of Porphyromonas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans. In addition, plaque, gingival redness, swelling, and bleeding scores were recorded with use of the California Dental Association scale. Statistical analysis was used to determine the effect of restoration/abutment type on levels of the bacterial species and clinical parameters pertaining to gingival health.
  
  
  RESULTS
  None of the sulci sampled contained detectable levels of the 3 bacteria. Plaque levels and gingival redness, swelling, and bleeding scores were low. All treatment groups had similar soft tissue response as measured by gingival redness, swelling, and bleeding. Plaque scores from all-ceramic crown/implant abutment sites were higher than plaque scores from all-ceramic crown/natural tooth sites. However, differences between experimental and control sites within the same treatment group were not observed (P>.05) with any of the 4 clinical measures.
  
  
  CONCLUSIONS
  In patients with suitable oral hygiene, tooth-supported and implant-supported crowns with intracrevicular margins were not predisposed to unfavorable gingival and microbial responses.
authors.affiliation: Faculty of Dentistry, National University of Tucuman Argentina, San Miguel de Tucuman, Argentina.
authors.forename: S G
authors.initials: SG
authors.lastname: Kancyper
authors.forename: S
authors.initials: S
authors.lastname: Koka
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000302:isolation & purification; D000537:Aluminum Oxide; D003442:Crowns / Q000009:adverse effects*; D004269:DNA, Bacterial / Q000032:analysis; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D003773:Dental Plaque / Q000382:microbiology*; D003776:Dental Porcelain; D005891:Gingivitis / Q000209:etiology*; D006801:Humans; D016876:Metal Ceramic Alloys; D016966:Porphyromonas gingivalis / Q000302:isolation & purification; D018713:Prevotella intermedia / Q000302:isolation & purification; D014025:Titanium
chemical_list: C105314:AllCeram; D004269:DNA, Bacterial; D015921:Dental Implants; D016876:Metal Ceramic Alloys; D003776:Dental Porcelain; D014025:Titanium; D000537:Aluminum Oxide