ABSTRACT
INTRODUCTION: The aim of this study was to evaluate the remineralization effect of NaF, NaF with TCP, NaF with CPP-ACP and NaF with CXP varnishes on newly erupted first permanent molars using laser fluorescence (LF) method. The study was a randomized, double-blind, controlled trial with four parallel groups. METHODS: The study was carried out in 48 high caries-risk children (DMFS >8), aged 6-7 years with newly erupted permanent first molars (initial lesion with 13 < LF value<30). A total of 140 teeth were divided randomly into four groups (n = 35): G1.Duraphat Varnish containing 5% NaF, G2. Clinpro™ White Varnish containing 5% NaF with TCP, G3.Embrace™ Varnish containing 5% NaF with CXP, G4. MI Varnish containing 5% NaF with CPP-ACP. All dental treatments of the patients were completed before the varnish application. The varnishes were applied to the targeted teeth at baseline, 1 and 3 months. Patients were called for follow-up appointments at 1, 3 and 6 months, and LF scanning was used to monitor mineralization changes. Data were analysed statistically by Wilcoxon signed-rank and Mann-Whitney U-tests. RESULTS: In total, 40 children (122 teeth) completed the trial. At the end of 6 months, the amount of reduction in LF values (indicating remineralization) are as follows: NaF with CXP(6.87 ± 4.32) < NaF with TCP(7.36 ± 7.05) < NaF(7.40 ± 7.03) < NaF with CPP-ACP(8.33 ± 4.90). All of the varnishes resulted in significant decrease in LF measurements and there was no significant difference between control (NaF alone) group and other groups. Only MI varnish had a significantly greater remineralization effect than Embrace™ Varnish (p < 0.05). CONCLUSION: As a non-invasive approach, CPP-ACP, TCP and CXP containing NaF varnishes have the potential to remineralize initial caries lesions on permanent first molars in high caries-risk children.
ABSTRACT
The aim of this study was to determine the temperature increase in the pulp chamber and possible thermal effects on molecular structure of primary teeth during the irradiation with Er,Cr:YSGG laser. Primary central incisors were divided into three groups (n = 20). Labial surfaces in each group were irradiated by Er,Cr:YSGG laser within different power and frequencies as following groups: I: 0.25 W, 20 Hz, II: 0.50 W, 20 Hz, III: 0.75 W, 20 Hz. A thermocouple was placed inside the pulp chamber so that the temperature increments were recorded during the enamel irradiation. Morphological changes of enamel surfaces were experimentally evaluated by SEM. Fourier-transform infrared spectroscopy and RAMAN analyses were carried out to determine the differentiations in the molecular structure. The experimental results obtained were analyzed statistically by means of one-way analysis of variance. Statistically significant differences were detected between groups (p < .05). Group III exhibited the highest values for the temperature parameters. Besides, the conical craters, cracks, and formation of ablation areas were observed for all the groups. Also, it was obtained that the hydroxyapatite lost the hydroxyl ions due to the thermal effect of the laser. Temperature rise throughout the Er,Cr:YSGG laser irradiation for prevention of primary enamel demineralization presented a positive correlation with the laser output power level. The formations of adverse morphological and spectral changes were detected on the surface of teeth after the laser application. On this basis, the Er,Cr:YSGG laser applications should be treated with much more caution considering enamel surface and pulpal tissues in primary teeth.
Subject(s)
Lasers, Solid-State , Dental Caries Susceptibility , Incisor , Lasers, Solid-State/therapeutic use , Temperature , Tooth, DeciduousABSTRACT
Objective: To evaluate in vitro the effect of the erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser on resistance of primary and permanent human enamel to demineralization using water cooling and fluoride coapplication as variable parameters. Methods: Enamel specimens were prepared from extracted primary and permanent teeth (n = 225 each). The specimens were separated into 15 subgroups (n = 15/group) based on laser application at three different power settings (0.25, 0.50, and 0.75 W), laser application with and without water cooling, and application of acidulated phosphate fluoride (APF) gel before laser treatment. Morphological changes were assessed with scanning electron microscopy (SEM), and the specimens' chemical contents were determined with energy-dispersive X-ray spectroscopy. Results: In both the primary and permanent teeth, the highest Ca and P content was observed in the noncooled 0.75 W laser group (p < 0.05), irrespective of APF pretreatment (p > 0.05). The Ca and P content for the noncooled APF +0.75 W laser group was lower than that for the APF group and the noncooled 0.75 W laser group. For both dentitions, the F mass content for the APF+laser groups was significantly higher than laser-only groups (p < 0.05). Under SEM, both the primary and permanent enamel exhibited cracks, craters, and surface roughness without water cooling, consistent with increased power output. Conclusions: Er,Cr:YSGG laser application at 0.75 W without water cooling increased enamel resistance to demineralization. Compared with topical APF application, Er,Cr:YSGG laser application barely improved enamel resistance against demineralization, and coapplication did not result in a synergistic effect.
