Influence of Diode Laser Application on the Efficiency of QMiX and EDTA Solutions in Removing Smear Layer

Dystrophic calcinosis: structural and morphological composition, and evaluation of ethylenediaminetetraacetic acid ('EDTA') for potential local treatment

BACKGROUND

To perform a detailed morphological analysis of the inorganic portion of two different clinical presentations of calcium-based deposits retrieved from subjects with SSc and identify a chemical dissolution of these deposits suitable for clinical use.

METHODS

Chemical analysis using Fourier Transform IR spectroscopy ('FTIR'), Raman microscopy, Powder X-Ray Diffraction ('PXRD'), and Transmission Electron Microscopy ('TEM') was undertaken of two distinct types of calcinosis deposits: paste and stone. Calcinosis sample titration with ethylenediaminetetraacetic acid ('EDTA') assessed the concentration at which the EDTA dissolved the calcinosis deposits in vitro.

RESULTS

FTIR spectra of the samples displayed peaks characteristic of hydroxyapatite, where signals attributable to the phosphate and carbonate ions were all identified. Polymorph characterization using Raman spectra were identical to a hydroxyapatite reference while the PXRD and electron diffraction patterns conclusively identified the mineral present as hydroxyapatite. TEM analysis showed differences of morphology between the samples. Rounded particles from stone samples were up to a few micron in size, while needle-like crystals from paste samples reached up to 0.5 µm in length. Calcium phosphate deposits were effectively dissolved with 3% aqueous solutions of EDTA, in vitro. Complete dissolution of both types of deposit was achieved in approximately 30 min using a molar ratio of EDTA/HAp of ≈ 300.

CONCLUSIONS

Stone and paste calcium-based deposits both comprise hydroxyapatite, but the constituent crystals vary in size and morphology. Hydroxyapatite is the only crystalline polymorph present in the SSc-related calcinosis deposits. Hydroxyapatite can be dissolved in vitro using a dosage of EDTA considered safe for clinical application. Further research is required to establish the optimal medium to develop the medical product, determine the protocol for clinical application, and to assess the effectiveness of EDTA for local treatment of dystrophic calcinosis.

Evaluation of EDTA, QMix, and Irritrol solutions activated with Er,Cr:YSGG and diode lasers on the push-out bond strength of filling material

This study was conducted to evaluate the effects of ethylenediaminetetraacetic acid (EDTA), Irritrol, and QMix solutions used with manual irrigation and diode and erbium, chromium-doped yttrium, scandium, gallium, and garnet (Er,Cr:YSGG) laser activation on the bonding ability of sealer to the intraradicular dentin. The root canals of 90 mandibular incisors were instrumented, and the teeth were allocated randomly to nine groups (n = 10/group) receiving final irrigation with different irrigation solutions (EDTA, Irritrol, and QMix) and irrigant activation techniques (manual, diode laser, and Er,Cr:YSGG laser). Following endodontic filling, three sections of 1-mm thickness were obtained from the middle third of each root. The root filling was subjected to a push-out test to examine the bond strength of the sealer to dentin. The test data were examined using analysis of variance with a significance level of ɑ < .05. Failure modes were determined by stereomicroscopy, and the surface characteristics of dentin were observed by scanning electron microscopy. Irritrol showed less push-out bond strength than did the other solutions in the Er,Cr:YSGG laser groups (p < .05). In the diode laser groups, QMix provided greater adhesion than did Irritrol (p < .05). The activation of QMix with the Er,Cr:YSGG laser increased the bond strength more than did manual irrigation (p < .05). No other significant difference was observed between other comparison pairs (p > .05). QMix provided adhesion superior to that of Irritrol when activated with diode and Er,Cr:YSGG lasers. Er,Cr:YSGG laser activation increased the adhesion of filling material with QMix irrigation.