Effect of Laser Activated Sodium Hypochlorite on Sealing Ability of Two Endodontic Sealers Using Stereomicroscope-An In vitro Study
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2021-01-01 |
| Journal | Open Access Journal of Dental Sciences |
| Authors | Kiranmayi Govula |
| Institutions | Narayana Dental College and Hospital |
| Citations | 1 |
| Analysis | Full AI Review Included |
Executive Summary
Section titled âExecutive SummaryâThis study investigates the engineering efficacy of laser-activated sodium hypochlorite (LA-NaOCl) irrigation on the sealing performance (microleakage) of two distinct endodontic sealers: an epoxy resin-based material (AH Plus) and a bioceramic material (Bio root RCS).
- Core Achievement: Laser activation of NaOCl significantly reduced microleakage compared to conventional NaOCl irrigation, demonstrating enhanced cleaning and improved sealer adhesion.
- Sealer Performance: The bioceramic sealer (Bio root RCS) consistently exhibited superior sealing ability (less dye penetration) compared to the AH Plus sealer across all irrigation protocols.
- Mechanism of Action: The 980 nm diode laser heats the NaOCl solution, which not only increases its immediate tissue dissolution capacity but also effectively removes the dentinal smear layer, thereby increasing dentin permeability.
- Adhesion Improvement: Removal of the smear layer facilitates better adhesion between the root canal sealer/gutta-percha and the radicular dentin wall.
- Quantitative Result (Vertical Leakage): The lowest mean vertical leakage score (4.63 ± 0.35 units) was achieved by the combination of LA-NaOCl and Bio root RCS (Group A1).
- Thermal Safety: Diode laser activation is confirmed as a viable method to increase NaOCl temperature while maintaining safety, keeping temperatures below the 55 °C threshold tolerable by surrounding tissues.
Technical Specifications
Section titled âTechnical Specificationsâ| Parameter | Value | Unit | Context |
|---|---|---|---|
| Laser Type | Diode | N/A | Used for NaOCl activation |
| Wavelength | 980 | nm | Diode Laser specification |
| Emission Mode | Continuous | N/A | Laser operation mode |
| Irradiation Cycle Time | 20 | Sec | Total irradiation time per canal |
| Peak Power | 1.5 | Watts | Laser output setting |
| Average Power | 0.7 | Watts | Laser output setting |
| Frequency | 15 | HZ | Pulse frequency |
| Duty Cycle | 50 | % | Laser operation cycle |
| NaOCl Concentration | Low | % | Used for laser activation |
| Bioceramic Sealer Expansion | Up to 0.2 | % | Expansion upon setting reaction |
| Vertical Leakage (LA-NaOCl + Bio root RCS) | 4.63 ± 0.35 | Units | Lowest leakage group (A1) Mean ± SD |
| Vertical Leakage (Standard NaOCl + AH Plus) | 8.57 ± 0.81 | Units | Highest leakage group (B2) Mean ± SD |
| Statistical Significance (A1 vs B1) | p < 0.001 | N/A | Significant difference in vertical leakage |
| Stereomicroscope Magnification | 30 | times | Used for microleakage measurement |
| Dye Immersion Duration | 72 | hours | Time stored in 1% methylene blue |
Key Methodologies
Section titled âKey MethodologiesâThe study employed a controlled in vitro methodology focusing on standardized sample preparation, precise laser application, and quantitative microleakage assessment.
- Sample Preparation: Forty extracted human single-rooted teeth were decoronated to a standardized length of 12 mm from the apex.
- Instrumentation: Root canals were prepared using a crown-down technique with Rotary Pro Taper files up to size F3, maintaining an 11 mm working length.
- Grouping (n=10 per group):
- Group A (Laser Activated): A1 (LA-NaOCl + Bio root RCS), A2 (LA-NaOCl + AH Plus).
- Group B (Control): B1 (NaOCl + Bio root RCS), B2 (NaOCl + AH Plus).
- Laser Activation Protocol: A 980 nm diode laser (1.5 W peak power, 50% duty cycle) was introduced apically and withdrawn helicoidally for a total irradiation time of 20 seconds per canal.
- Obturation: All canals were filled using the lateral condensation technique with gutta-percha and the assigned sealer (AH Plus or Bio root RCS).
- Leakage Induction: Samples were coated with nail varnish (2 mm short of the apex) and submerged in freshly prepared 1% methylene blue dye for 72 hours.
- Measurement: Roots were split longitudinally. Dye penetration depth (microleakage) was measured at 2, 4, and 6 mm from the apex using a stereomicroscope at 30x magnification.
- Data Conversion: Measured units were converted to millimeters (vertical penetration) and micrometers (horizontal penetration) for statistical analysis (Independent Sample t-test).
Commercial Applications
Section titled âCommercial ApplicationsâThe findings support the development and optimization of advanced dental and biomedical technologies, particularly those involving laser-material interaction and high-performance sealing materials.
- Advanced Endodontic Systems: Design and integration of 980 nm diode lasers into irrigation systems for enhanced root canal disinfection and cleaning efficiency.
- Bioceramic Material Engineering: Validation of bioceramic sealers (Bio root RCS) for superior adhesion and sealing performance in complex biological environments, driven by their hydrophilic nature and controlled expansion.
- Medical Device Sterilization: Application of laser-activated chemical solutions for rapid and effective decontamination of complex microstructures, leveraging enhanced bactericidal action.
- Smear Layer Removal Technology: Development of protocols and devices specifically targeting the removal of debris layers on hard tissues to maximize bonding strength for restorative materials.
- Thermal Management in Medical Lasers: Engineering laser delivery systems that efficiently transfer heat to irrigants (like NaOCl) to boost chemical efficacy while strictly maintaining tissue-safe temperature limits (below 55 °C).
View Original Abstract
Introduction: The combination of various irrigants, irrigation techniques along with root canal sealers helps in achieving a three-dimensional seal in root canals, which is of clinical relevance. The present in-vitro study aims to assess and compare the efficacy of laser-activated NaOCl on the sealing ability of two endodontic sealers. Materials and Methods: Forty extracted human single-rooted permanent teeth were collected and decoronated 12 mm from their apices. Instrumentation did with an 11 mm working length using Rotary Pro taper files to F3. All the teeth grouped into four (n= 10) based on irrigation protocol and sealer used as follows: Group A1 - Laser activated NaOCl + AH Plus Group A2 - Laser activated NaOCl +nano seal, Group B1 - NaOCl + AH Plus, Group B2 - NaOCl + nano seal. The lateral condensation technique did obturation. Roots stored in freshly prepared 1% methylene blue for 72 hours. The roots were split longitudinally along the long axis using a diamond disc underwater coolant, and markings made at 2, 4, and 6 mm from the apex. The depth of dye penetration and microleakage examined under a stereomicroscope (Magnus) at 30Ă magnification. Results: Statistical analysis carried out by using the software, statistical package for social sciences [SPSS]. Results represented in the form of minimum, mean, and standard deviation. Conclusion: The laser-activated NaOCl group exhibited better sealing ability than the control group. Among the two sealers, the Bio root RCS sealer showed less leakage & better sealing ability than AH plus Clinical Significance: Increasing the temperature of low concentration sodium hypochlorite solution by the action of the diode laser, not only enhances its immediate tissue dissolution capacity but also increased the dentin permeability by removing the smear layer. Further leading to better adhesion between the root canal sealer and the gutta-percha with the radicular dentin.