title: Periodontal response to two different subgingival restorative margin designs: a 12-month randomized clinical trial.
abstract: OBJECTIVE
  Subgingival margin placement is sometimes required due to different reasons and is often associated with adverse periodontal reactions. The purpose of this study was to determine if a single restoration with subgingival margin on a tooth, in the maxillary anterior zone, would affect its periodontal soft tissue parameters, and whether or not a deep chamfer preparation has a different influence in the periodontium when compared to a feather edge preparation.
  
  
  METHODS
  Plaque and gingival indexes, periodontal probing depth, bleeding on probing, and patient's biotype were registered. One hundred six teeth were prepared with a deep chamfer, while 94 were prepared with a feather edge finishing line. Twelve months after the restoration delivery, the same parameters were evaluated. Repeated measure one-way analysis of variance (ANOVA) (α = 0.05) was used.
  
  
  RESULTS
  A statistically significant difference between the baseline and the 12-month follow-up is present in regard to plaque index, gingival index, and periodontal probing depth, but no statistically significant difference between chamfer and feather edge finishing lines. There is a statistically significant difference between the baseline and the 12-month follow-up in regard to bleeding on probing. Feather edge preparation presents significantly more bleeding on probing and less gingival recession than the chamfer.
  
  
  CONCLUSIONS
  Subgingival margins do influence the periodontal soft tissue response. Statistically significant difference exists between feather edge and chamfer finishing lines in regard to bleeding on probing and gingival recession.
  
  
  CONCLUSIONS
  Subgingival margins should be carefully selected, especially when feather edge finishing line is utilized.
authors.affiliation: Department of Prosthodontics, Tufts University School of Dental Medicine, Boston, MA, USA.|Department of Prosthodontics, School of Dentistry, University of Padova, Padova, Italy.
authors.forename: Gianluca
authors.initials: G
authors.lastname: Paniz
authors.affiliation: Department of Periodontology, Universitat Internacional de Catalunya, c/ Josep Trueta s/n, Barcelona, Spain. jose@nartperiodoncia.com.
authors.forename: Jose
authors.initials: J
authors.lastname: Nart
authors.affiliation: Department of Periodontology, Harvard University School of Dental Medicine, Boston, MA, USA.|Department of Periodontology, School of Dentistry, University of Padova, Padova, Italy.
authors.forename: Luca
authors.initials: L
authors.lastname: Gobbato
authors.affiliation: Private Practice limited to Periodontics, Verona, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Chierico
authors.affiliation: Department of Prosthodontics, School of Dentistry, S. Paul Hospital, University of Milan, Milan, Italy.
authors.forename: Diego
authors.initials: D
authors.lastname: Lops
authors.affiliation: Department of Prosthodontics, Tufts University School of Dental Medicine, Boston, MA, USA.|Department of Prosthodontics, Faculty of Health Sciences, Aristotle University School of Dentistry, Thessaloniki, Greece.
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Michalakis
mesh_terms: D000328:Adult; D018772:Dental Marginal Adaptation; D003774:Dental Plaque Index; D003793:Dental Restoration, Permanent / Q000379:methods*; D004311:Double-Blind Method; D004955:Esthetics, Dental; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla; D008875:Middle Aged; D010510:Periodontal Diseases / Q000175:diagnosis*; D010512:Periodontal Index; D011446:Prospective Studies; D016896:Treatment Outcome
keywords: All-ceramic restoration; Bleeding on probing; Periodontal response; Recession; Subgingival margin