title: Comparative clinical efficacy evaluation of three gingival displacement systems.
abstract: OBJECTIVE
  We compared the clinical efficacy of three gingival displacement systems to accurately record intra-crevicular margins of tooth preparation.
  
  
  METHODS
  One mechanical (magic foam cord) and two chemico-mechanical (expasyl paste and retraction cord impregnated with 15% aluminum chloride) gingival displacement systems were used. This study was conducted on the maxillary central incisors of 20 patients (20-60 years old) requiring full coverage restoration. All the three gingival displacement systems were tested in three sessions at an interval of 14 days in same order. The casts were sectioned and viewed under an optical microscope, followed by quantitative measurements of the width of the pre and postretracted sulci.
  
  
  RESULTS
  All the three displacement systems produced highly significant horizontal gingival displacement. Retraction cord soaked in 15% aluminum chloride produced maximum displacement (0.74 mm), followed by expasyl paste (0.48 mm) whereas magic foam cord produced the least displacement (0.41 mm).
  
  
  CONCLUSIONS
  Gingival displacement shown by each displacement system was found to be more than the accepted value necessary for elastomeric impression accuracy (0.2 mm) to record intra-crevicular margins of tooth preparation.
authors.affiliation: Department of Prosthodontics, People's Dental Academy, Bhopal, Madhya Pradesh, India.
authors.forename: Kirti Jajoo
authors.initials: KJ
authors.lastname: Shrivastava
authors.affiliation: Department of Prosthodontics, People's College of Dental Sciences, Bhopal, Madhya Pradesh, India.
authors.forename: Anjali
authors.initials: A
authors.lastname: Bhoyar
authors.affiliation: Department of Prosthodontics, People's College of Dental Sciences, Bhopal, Madhya Pradesh, India.
authors.forename: Surendra
authors.initials: S
authors.lastname: Agarwal
authors.affiliation: Department of Prosthodontics, RKDF Dental College, Bhopal, Madhya Pradesh, India.
authors.forename: Saurabh
authors.initials: S
authors.lastname: Shrivastava
authors.affiliation: Department of Prosthodontics, People's College of Dental Sciences, Bhopal, Madhya Pradesh, India.
authors.forename: Swapnil
authors.initials: S
authors.lastname: Parlani
authors.affiliation: Department of Prosthodontics, Indira Gandhi Institute of Dental Sciences, Pillayarkuppam, Puducherry, India.
authors.forename: Varsha
authors.initials: V
authors.lastname: Murthy
keywords: Expasyl paste; gingival retraction cord; intracrevicular margin; magic foam cord; tooth preparation