title: Comparative Study of the Effect of Acid Etching on Enamel Surface Roughness between Pumiced and Non-pumiced Teeth.
abstract: BACKGROUND
  The objective was to perform a comparative analysis of the effect of acid etching on enamel roughness between pumiced and non-pumiced teeth.
  
  
  METHODS
  The sample was composed of 32 dental surfaces divided into two groups: Group 1-16 surfaces having received pumice prophylaxis; and Group 2-16 surfaces not having received pumice prophylaxis. The teeth were kept in saline until the first record of surface roughness prior to etching. For each surface, a roughness graph was obtained through trials using a surface roughness tester. This procedure was repeated two more times at different locations for a total of three readings which, later, were converted in a mean value. The teeth were then acid etched with a 37% phosphoric acid for 60 s, rinsed with water, air dried, and tested with the roughness tester again using the same protocol described for baseline. The Quantikov image analysis program was used to measure the length of the graphs. The average value of the lengths was recorded for each surface before and after etching. The increase in roughness caused by acid etching was calculated and compared between groups.
  
  
  RESULTS
  The mean increase in roughness caused by the etching was 301 µm (11.37%) in Group 1 and 214 µm (8.33%) in Group 2. No statistically significant difference was found between samples with and without pumice prophylaxis (P = 0.283).
  
  
  CONCLUSIONS
  The present study showed that the effect of acid etching on enamel roughness was not significantly affected by prior pumice prophylaxis.
authors.affiliation: PhD Student, Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Lucas Guimarães
authors.initials: LG
authors.lastname: Abreu
authors.affiliation: Professor, Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Saul Martins
authors.initials: SM
authors.lastname: Paiva
authors.affiliation: Associate Professor, Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Henrique
authors.initials: H
authors.lastname: Pretti
authors.affiliation: Associate Professor, Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: Elizabeth Maria Bastos
authors.initials: EM
authors.lastname: Lages
authors.affiliation: Associate Professor, Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
authors.forename: João Batista Novães
authors.initials: JB
authors.lastname: Júnior
authors.affiliation: Senior Researcher, Department of Engineering, Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, Brazil.
authors.forename: Ricardo Alberto Neto
authors.initials: RA
authors.lastname: Ferreira
keywords: Dental acid etching; dental bonding; dental enamel