title: In vitro study on micro-hardness of resin-modified glass ionomers at different depths.
abstract: OBJECTIVE
  It is very important to perform studies to evaluate micro-hardness and curation level at different depths to refine the clinical indications and orientations that the odontologist gives to the patients, helping to achieve more durable treatments when using resin-modified glass ionomers. This in vitro study evaluated knoop micro-hardness in 2 different brands of resin-modified glass ionomers: Ketac ™ N100 (M1) and Fuji II LC (M2).
  
  
  METHODS
  Tests were performed at three depths: surface (P1), 2 mm (P2) and 3 mm (P3). A total of 40 samples where made (20 of each type of resin), half of these measuring 5 x 2 mm and the other half with 5 x3 mm. To evaluate micro-hardness at different depths, 24 hours after the manufacture of samples, tests where made on both top and bottom surfaces. These tests were performed using an HMV-200 Micro Hardness Tester (Shimadzu brand). For statistical analysis data were collected and used first for ANOVA variance analysis (P≤0.01) followed then by Turkey's test.
  
  
  RESULTS
  It also shows that the effect is not significant for the interaction between material and depth. Micro-hardness on P1 (34.7) is statistically greater than with P2 (29.2) and P3 (29.0) and these last two are statistically equal between them. M1 (27.8) presented less micro-hardness than M2 (34.2).
  
  
  CONCLUSIONS
  Surface micro-hardness is greater than micro-hardness at other depths and M2 presented better results than M1.
authors.affiliation: Pierre Fauchard Autonomous, University of Paraguay, Asunción, Paraguay. deugarten@gmail.com
authors.forename: D
authors.initials: D
authors.lastname: Ugarte Núñez
authors.forename: A
authors.initials: A
authors.lastname: Terossi De Godoi
authors.forename: D
authors.initials: D
authors.lastname: De Biagi Freitas
authors.forename: A B C
authors.initials: AB
authors.lastname: Catirse
mesh_terms: D005899:Glass Ionomer Cements; D006245:Hardness Tests; D008277:Magnesium Oxide; D008422:Materials Testing; D011076:Polycarboxylate Cement; D019279:Resin Cements; D012117:Resins, Synthetic; D013499:Surface Properties; D015034:Zinc Oxide
chemical_list: C079765:Fuji II LC cement; D005899:Glass Ionomer Cements; D011076:Polycarboxylate Cement; D019279:Resin Cements; D012117:Resins, Synthetic; D008277:Magnesium Oxide; C040235:Ketac-cem; D015034:Zinc Oxide