Qualitative microanalysis of ions and ultrastructural changes in dentin exposed to laser irradiation and to metal salts solution

Background and Objectives This study evaluated the ultrastructural changes in dentin after treatment with the Nd:YAG laser and/or metal salt solutions and verified the presence of Sn ++ , Sr ++ , and F − in dentin structure. Study Designs/Materials and Methods Sixty dentin disks were randomly divided into groups (n = 10): (I) control (no treatment), (II) Nd:YAG (1.5 W, 100 mJ, 15 Hz, 125 J/cm 2 ), (III) 10% SnF 2 aqueous solution for 30 minutes, (IV) Nd:YAG+10% SnF 2 aqueous solution for 30 minutes, (V) 10% SrCl 2 toothpaste for 30 minutes, (VI) Nd:YAG+10% SrCl 2 toothpaste for 30 minutes. Then, all samples were prepared for scanning electron microscopy (SEM) and the samples from Groups I to IV for the energy dispersive X‐ray microanalysis (EDX). Results SEM evaluation revealed occluded dentinal tubules and a dentin surface altered by the laser irradiation. The EDX microanalysis revealed Sn ++ at a depth of 250 μm in Group IV and not deeper than 100 μm in Group III. In Group V, Sr ++ was not deeper than 50 μm, but it could be detected at a depth of 500 μm in Group VI. F − was found only in Group IV. Conclusions Ultrastructural changes caused by laser irradiation can increase dentin uptake of Sn ++ , Sr ++ , and F − . © 2005 Wiley‐Liss, Inc.