Effect of smear layer on root demineralization adjacent to resin-modified glass ionomer.
The cariostatic effect of resin-modified glass ionomer (RMGI) on secondary root caries is well-documented. However, this beneficial effect may be dependent upon the mode of cavity surface treatment. To investigate this relationship, we studied 4 cavity surface treatments prior to the placement of RMGI: no treatment (None), polyacrylic acid (PAA), phosphoric acid (H(3)PO(4)), and Scotchbond Multi-Purpose adhesive (SMP) as a control. Specimens were aged for two weeks in synthetic saliva, thermocycled, and subjected to an artificial caries challenge (pH 4.4). Polarized light microscopy (PLM) and microradiography (MRG) showed significantly less demineralization with the H(3)PO(4) cavity surface treatment as revealed by ANOVA and Tukey's multiple comparisons (p < or = 0.05). Dentin fluoride profiles determined by electron probe microanalysis (EPMA) supported PLM and MRG findings. It may be concluded that removal of the smear layer with phosphoric acid provides significantly enhanced resistance to secondary root caries formation adjacent to RMGI restorations.
AL-Helal
A S
AS
Dows Institute for Dental Research, College of Dentistry N413, The University of Iowa, Iowa City, IA 52242-1010, USA.
Armstrong
S R
SR
Xie
X J
XJ
Wefel
J S
JS
D000134:Acid Etching, Dental; D000180:Acrylic Resins / Q000494:pharmacology; D000704:Analysis of Variance; D002327:Cariostatic Agents / Q000627:therapeutic use; D003737:Dental Cavity Preparation; D003793:Dental Restoration, Permanent / Q000379:methods; D003804:Dentin / Q000187:drug effects*; D004577:Electron Probe Microanalysis; D005459:Fluorides / Q000627:therapeutic use; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006801:Humans; D008852:Microradiography; D008855:Microscopy, Electron, Scanning; D008859:Microscopy, Polarization; D008963:Molar; D010756:Phosphoric Acids / Q000494:pharmacology; D017213:Root Caries / Q000517:prevention & control*; D055502:Secondary Prevention; D016369:Smear Layer; D018709:Statistics, Nonparametric; D013499:Surface Properties; D017001:Tooth Demineralization / Q000517:prevention & control*
D000180:Acrylic Resins; D002327:Cariostatic Agents; D005899:Glass Ionomer Cements; D010756:Phosphoric Acids; C006903:carbopol 940; C030242:phosphoric acid; D005459:Fluorides