title: Evaluation of dentinal tubule occlusion and depth of penetration of nano-hydroxyapatite derived from chicken eggshell powder with and without addition of sodium fluoride: An in vitro study.
abstract: OBJECTIVE
  This in vitro study evaluated the degree of dentinal tubule occlusion and depth of penetration of nano-hydroxyapatite (nHAp) derived from chicken eggshell powder with and without the addition of 2% sodium fluoride (NaF) using scanning electron microscope (SEM) and confocal laser scanning microscope (CLSM).
  
  
  METHODS
  nHAp was synthesized and characterized using X-ray diffraction and SEM-energy dispersive spectroscopy. Dentin discs were obtained from extracted teeth, pretreated with 17% ethylenediaminetetraacetic acid for 5 min and were divided into four groups based on the experimental agents as follows: Group 1: Untreated (control), Group 2: 2% NaF, Group 3: nHAp, Group 4: Combination of nHAp and 2% NaF. The treatment protocol was carried out for 7 days, after which the specimens were viewed under SEM and CLSM.
  
  
  METHODS
  One-way ANOVA and Tukey's post hoc multiple comparison tests (P < 0.05).
  
  
  RESULTS
  All the experimental agents occluded the dentinal tubules, but to varying degrees and depths. Specimens treated with the combination of nHAp and 2% NaF showed complete dentinal tubular occlusion and significantly greater depth of penetration than those treated with nHAp and 2% NaF alone.
  
  
  CONCLUSIONS
  The combination of nHAp and 2% NaF was the most effective in occluding dentinal tubules.
authors.affiliation: Department of Conservative Dentistry and Endodontics, SRM Dental College, Chennai, Tamil Nadu, India.
authors.forename: Divya
authors.initials: D
authors.lastname: Kunam
authors.affiliation: Department of Conservative Dentistry and Endodontics, SRM Dental College, Chennai, Tamil Nadu, India.
authors.forename: Sujatha
authors.initials: S
authors.lastname: Manimaran
authors.affiliation: Department of Conservative Dentistry and Endodontics, SRM Dental College, Chennai, Tamil Nadu, India.
authors.forename: Vidhya
authors.initials: V
authors.lastname: Sampath
authors.affiliation: Department of Conservative Dentistry and Endodontics, SRM Dental College, Chennai, Tamil Nadu, India.
authors.forename: Mahalaxmi
authors.initials: M
authors.lastname: Sekar
keywords: Dentin hypersensitivity; desensitizing agents; eggshells; hydroxyapatite; sodium fluoride; tubule occlusion