title: Influence of citric acid on the surface texture of glass ionomer restorative materials.
abstract: OBJECTIVE
  This study determined the effectiveness of G-coat plus surface protective agent over petroleum jelly on the surface texture of conventional Glass ionomer restorative materials.
  
  
  METHODS
  Three chemically cured conventional glass ionomer restorative materials type II, type IX and ketac molar were evaluated in this study. Sixty specimens were made for each restorative material. They were divided into two groups of thirty specimens each. Of the sixty specimens, thirty were coated with G-coat plus (a nano-filler coating) and the rest with petroleum jelly. Thirty samples of both protective coating agents were randomly divided into six groups of five specimens and conditioned in citric acid solutions of differing pH (pH 2, 3, 4, 5, 6 & 7). Each specimen was kept in citric acid for three hours a day, and the rest of time stored in salivary substitute. This procedure was repeated for 8 days. After conditioning, the surface roughness (Ra, μm) of each specimen was measured using a surface profilometer (Taylor & Habson, UK). Data was analyzed using one-way analysis of variance (ANOVA) and Tukey's HSD test at a significance level of 0.05.
  
  
  RESULTS
  The surface textures of all the tested glass ionomer restorative materials protected with G-coat plus were not significantly affected by acids at low pH. The surface textures of all the tested glass ionomer restorative materials protected with petroleum jelly coating were significantly affected by acids at low pH.
  
  
  CONCLUSIONS
  The effects of pH on the surface texture of glass ionomer restoratives are material dependent. Among all the materials tested the surface texture of Type II GIC (Group I) revealed marked deterioration when conditioned in solutions of low pH and was statistically significant. Hence, a protective coating either with G-coat plus or with light polymerized low viscosity unfilled resin adhesives is mandatory for all the glass ionomer restorations to increase the wear resistance of the restorative materials.
authors.affiliation: Reader, Department of Conservative Dentistry and Endodontics, C.K.S Theja Institute of Dental Sciences and Research, Tirupathi, Andhra Pradesh, India.
authors.forename: Dappili Swami Ranga
authors.initials: DS
authors.lastname: Reddy
authors.affiliation: Professor, Departments of Conservative Dentistry and Endodontics, Ragas Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: Ramachandran Anil
authors.initials: RA
authors.lastname: Kumar
authors.affiliation: Reader, Departments of Conservative Dentistry and Endodontics, Ragas Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: Sokkalingam Mothilal
authors.initials: SM
authors.lastname: Venkatesan
authors.affiliation: Professor, Departments of Conservative Dentistry and Endodontics, Ragas Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: Gopal Shankar
authors.initials: GS
authors.lastname: Narayan
authors.affiliation: Reader, Sri Venkateswara Dental College, Chennai, Tamil Nadu, India.
authors.forename: Dasarathan
authors.initials: D
authors.lastname: Duraivel
authors.affiliation: Professor and Head, Departments of Conservative Dentistry and Endodontics, Ragas Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: Rajamani
authors.initials: R
authors.lastname: Indra
keywords: Citric acid; G-coat plus; ketac molar; nano filler