Comparing fibroblast attachment in root surface scaling with Er, Cr:YSGG laser versus ultrasonic scaler: A SEM study

Effect of erbium yttrium aluminium garnet laser dentin conditioning on dental pulp stem cells viability

Objective

This study aims to investigate the effect of dentin conditioning by subablative Er:YAG (erbium-doped yttrium aluminium garnet) laser on dental pulp stem cells (DPSCs) viability.

Methods

For this in-vitro experimental study, root fragments were longitudinally hemisected after decoronation of single-rooted extracted teeth and preparation of root canals. Prepared samples were randomly assigned to 2 experimental groups (n = 17) as follows; 1) laser conditioning: irradiation with Er:YAG laser beams (2940 nm, 50 mJ per pulse, 20 Hz) 2) Chemical conditioning: 1.5% NaOCl, followed by phosphate-buffered saline (PBS), 17% EDTA, followed by PBS as a final rinse. The samples were ultraviolet-sterilized, and DPSCs were seeded on the samples. MTT assay was performed after 1, 4 and 7 days of incubation to assess the cell viability (n = 5/group per day). Also, after 7 days, two samples of each group underwent SEM (scanning electron microscope) analysis. Statistical analysis was done using independent t-test, one-way ANOVA and two-way ANOVA at a significance level of 0.05.

Results

Laser irradiated samples exhibited significantly higher cell viability of DPSCs on days 4 (p < 0.0001) and 7 (p < 0.0001), unlike day 1 (p = 0.131). SEM photomicrographs revealed that Er:YAG laser performed much better smear layer removal and created surface irregularities. Several different cell morphologies were observable on the laser-treated samples, which cells with cytoplasmic extensions being the most frequent.

Conclusions

Dentin conditioning by Er:YAG laser enhances DPSCs viability and can be a valuable modality for conditioning dentin to perform regenerative endodontic procedures. Further clinical studies are suggested.

Comparative evaluation of combined efficacy of methylene blue mediated antimicrobial photodynamic therapy (a-PDT) using 660 nm diode laser versus Erbium-chromium-yttrium-scandium-gallium-garnet (Er, Cr: YSGG) laser as an adjunct to scaling and root planing on clinical parameters in supportive periodontal therapy: A randomized split-mouth trial

AIM

The aim of this study was to evaluate combined efficacy of methylene blue mediated antimicrobial photodynamic therapy (a-PDT) using 660 nm diode laser versus Er, Cr: YSGG laser as an adjunct to scaling and root planing on improving the Probing depth (PD), Clinical attachment level (CAL), Plaque Index (PI) and Gingival Index (GI).clinical parameters in Supportive periodontal therapy.

MATERIALS AND METHOD

In this split-mouth, double-blind, randomized controlled trial, we compared a-PDT versus Er,Cr:YSGG as an adjunct to scaling and root planning (SRP) with SRP alone in Supportive periodontal therapy. A total of 36 subjected were enrolled. In each patient, two quadrants constituted the control group (Group I - Scaling and root planing SRP alone), one site in other quadrant constituted the test group 1 (Group II - SRP followed by application of Er, Cr: YSGG laser), and another site in different quadrant constituted the test group 2 (Group III - SRP followed by antimicrobial Photodynamic therapy using diode laser). The diode laser was operated at a peak power of 70 mW using a 0.6 mm diameter fiber-optic tip. Each site was irradiated with a power density of 28 mW/cm², for 10 s, thus delivering a total energy of 16.72 J/cm² per tooth. Whereas, the Er,Cr:YSGG laser's parameters were set to 1 W of power, 10% air, and 15% water. The same procedure was repeated at 1st, 2nd and 3rd week for both the laser therapies. Plaque index (PI), Gingival index (GI), Probing depth (PD,) and Clinical attachment level (CAL) were measured by a single examiner at baseline and 3 months follow up. Inter group analysis of the parameters were done using One-way ANOVA and pairwise comparison was carried out by Tukey's post hoc test. Intra group analysis was performed using Students's paired t test. Statistical significance was set to p < 0.05.

RESULTS

There were no significant differences between participants for clinical parameters at baseline. PI, GI PD, and CAL significantly improved at 3 months follow up compared to baseline in both the study groups (Group II - SRP + Er,Cr:YSGG, Group III - SRP + a-PDT) with P < 0.05. Adjunctive use of Er,Cr:YSGG laser with SRP showed better clinical outcomes than a-PDT with SRP.

CONCLUSION

Nonsurgical periodontal therapy of chronic periodontitis using Er, Cr: YSGG, and a-PDT as an adjunct to SRP was significantly more effective than SRP alone in reducing PD, CAL, GI, and PI at 3 months follow up. Adjunctive use of Er,Cr:YSGG laser with SRP showed better clinical outcomes than a-PDT with SRP. However, the long-term positive benefits of the laser therapies are yet unknown and more research with longer follow-ups are required.