title: Surface roughness and enamel loss with two microabrasion techniques.
abstract: OBJECTIVE
  The aim of this study was to evaluate and compare the surface roughness and enamel loss produced by two microabrasion techniques.
  
  
  METHODS
  Bovine teeth were selected and an area was delimited for microabrasion techniques. Surface roughness was determined before and after treatment using a digital profilometer. Specimens were randomized to one of two acid treatments (n = 10): 18% hydrochloric acid (HCl) and pumice or 37% phosphoric acid (H3PO4) and pumice. Acid treatments were applied using a wooden spatula for 5 seconds for a total of ten applications. Then, specimens were sectioned through the center of the demineralization area to obtain 80 microm thick slices. The wear produced by the microabrasion techniques was evaluated using stereomicroscopy (40 x). The greatest depth (microm) and the total surface area (microm(2)) of demineralization were measured using the Image Tool software (University of Texas Health Science, San Antonio, TX, USA). In addition, three specimens of each group were subjected to SEM analysis at different magnifications.
  
  
  RESULTS
  The mean surface roughness was statistically lower for HCl than for H3PO4 (p < 0.001). Deeper demineralization (p < 0.003) and a larger total demineralization area was observed for HCl (p < 0.005). Under SEM analysis H3PO4 showed a selective conditioning etching, while HCl exhibited a non-selective pattern.
  
  
  CONCLUSIONS
  Microabrasion using H3PO4 produced greater surface roughness but less demineralization than the microabrasion technique using HCl.
  
  
  CONCLUSIONS
  Both microabrasion techniques effectively remove the superficial enamel layer. However, the technique using H3PO4 was less aggressive, safer, and easier to perform.
authors.affiliation: Department of Operative Dentistry, Federal University of Paraíba, João Pessoa, PB, Brazil. soniasaeger@hotmail.com
authors.forename: Sonia Saeger
authors.initials: SS
authors.lastname: Meireles
authors.forename: Darvi de Almeida
authors.initials: Dde A
authors.lastname: Andre
authors.forename: Ferdinan Luis
authors.initials: FL
authors.lastname: Leida
authors.forename: Jorge Saldivar
authors.initials: JS
authors.lastname: Bocangel
authors.forename: Flavio Fernando
authors.initials: FF
authors.lastname: Demarco
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000818:Animals; D002417:Cattle; D003743:Dental Enamel / Q000187:drug effects / Q000648:ultrastructure; D019243:Enamel Microabrasion / Q000379:methods*; D006851:Hydrochloric Acid / Q000494:pharmacology; D008855:Microscopy, Electron, Scanning; D010756:Phosphoric Acids / Q000494:pharmacology; D011897:Random Allocation; D017640:Silicates; D013499:Surface Properties
chemical_list: D010756:Phosphoric Acids; D017640:Silicates; C030242:phosphoric acid; C005144:pumice; D006851:Hydrochloric Acid