title: Evaluation of physical properties of enamel after microabrasion, polishing, and storage in artificial saliva.
abstract: This study evaluated the effect of microabrasion and polishing on the microhardness and roughness of bovine enamel, and the effect of artificial saliva on the hardness of enamel. Bovine enamel blocks were used, forming the groups (n = 48): GI-37% phosphoric acid and pumice, GII--Opalustre, and GIII--Whiteness RM. The groups were divided into different subgroups: (a) diamond paste, (b) fluoride prophylactic paste, and (c) without polishing. Hardness tests were carried out at the following set times: (T1) initial, (T2) after microabrasion and polishing, (T3) after immersion in artificial saliva for 24 h; and (T4) after seven days of immersion. Surface roughness tests were performed. The obtained data were analyzed by two-factor ANOVA and Tukey's test with significance of 5%. Microhardness increased in T2; without polishing, only groups GII and GIII showed an increased microhardness. T3 did not differ from T4; GI, GII and GIII did not provide surface roughness that differed from each other; and all microabrasive systems followed by polishing showed a higher surface smoothness compared with the control groups. It is concluded that microabrasion followed by polishing provided higher hardness and better surface smoothness of the enamel. However, immersion in artificial saliva was not able to increase the enamel hardness.
authors.affiliation: Department of Restorative Dentistry, Piracicaba Dental School, PO BOX 52 University of Campinas-UNICAMP 13414-903, Piracicaba, São Paulo, Brazil.
authors.forename: L S M
authors.initials: LS
authors.lastname: Fragoso
authors.forename: D A N L
authors.initials: DA
authors.lastname: Lima
authors.forename: R S
authors.initials: RS
authors.lastname: de Alexandre
authors.forename: C E S
authors.initials: CE
authors.lastname: Bertoldo
authors.forename: F H B
authors.initials: FH
authors.lastname: Aguiar
authors.forename: J R
authors.initials: JR
authors.lastname: Lovadino
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D017554:Carbon Compounds, Inorganic / Q000737:chemistry; D002417:Cattle; D045424:Complex Mixtures / Q000737:chemistry; D003743:Dental Enamel / Q000737:chemistry / Q000187:drug effects*; D003802:Dentifrices / Q000494:pharmacology*; D006244:Hardness; D006851:Hydrochloric Acid / Q000737:chemistry; D008855:Microscopy, Electron, Scanning / Q000379:methods; D010756:Phosphoric Acids / Q000737:chemistry; D019946:Propylene Glycol / Q000737:chemistry; D012464:Saliva, Artificial / Q000494:pharmacology; D017640:Silicates / Q000737:chemistry; D017655:Silicon Compounds / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors
chemical_list: D017554:Carbon Compounds, Inorganic; D045424:Complex Mixtures; D003802:Dentifrices; D010756:Phosphoric Acids; D012464:Saliva, Artificial; D017640:Silicates; D017655:Silicon Compounds; C539075:opalustre; D019946:Propylene Glycol; C030242:phosphoric acid; C005144:pumice; D006851:Hydrochloric Acid; C022088:silicon carbide