Tensile Bond Strength and Adaptability of One-bottle One-step Bonding Systems to Dental Hard Tissues Irradiated by Er -YAG Laser
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2015-01-01 |
| Journal | Journal of Japanese Society for Laser Dentistry |
| Authors | Naohiro Iwata, Keita Yokota, Youhei Hirota, Kenzo Yasuo, Kazushi Yoshikawa |
| Institutions | Osaka Dental University |
| Citations | 3 |
| Analysis | Full AI Review Included |
Technical Analysis and Documentation: Er:YAG Laser Interaction with Hard Tissues
Section titled âTechnical Analysis and Documentation: Er:YAG Laser Interaction with Hard TissuesâExecutive Summary
Section titled âExecutive SummaryâThis documentation analyzes research concerning the adhesive performance of one-step bonding systems on dental hard tissues (enamel and dentin) following Er:YAG laser irradiation. The findings highlight critical material stability challenges under thermal and laser stress, underscoring the need for ultra-stable materials like MPCVD diamond in advanced biomedical and laser systems.
- Core Application: Evaluation of dental adhesive integrity on bovine/human teeth surfaces pre-treated with an Er:YAG laser (100mJ, 10pps).
- Enamel Stability: Enamel surfaces maintained high tensile bond strength and marginal integrity regardless of laser irradiation or thermal cycling (up to 5,000 cycles).
- Dentin Compromise: Laser-irradiated dentin showed a significant and progressive decrease in tensile bond strength, failing completely (measurement impossible) after 5,000 thermal cycles for all bonding systems tested.
- Failure Mechanism: Laser irradiation induced a brittle, heat-affected layer (approximately 10”m thick) in the dentin, causing a shift from adhesive failure to cohesive failure within the weakened substrate.
- Thermal Stress: Thermocycling (5°C to 55°C) significantly accelerated the degradation of the adhesive interface on lased dentin, demonstrating the severe mechanical stress induced by temperature fluctuations.
- 6CCVD Value Proposition: The study validates the extreme thermal and mechanical stability required for components in high-precision laser delivery and biomedical testing equipment, areas where 6CCVDâs SCD and PCD materials excel.
Technical Specifications
Section titled âTechnical SpecificationsâThe following hard data points were extracted from the experimental methodology and results:
| Parameter | Value | Unit | Context |
|---|---|---|---|
| Laser Type | Er:YAG | N/A | Used for tissue ablation/treatment |
| Laser Energy Density | 100 | mJ | Irradiation condition |
| Pulse Repetition Rate | 10 | pps | Irradiation condition |
| Thermal Cycling Range | 5 to 55 | °C | Stress testing environment |
| Thermal Cycling Dwell Time | 30 | s | Time spent at each temperature extreme |
| Maximum Thermal Cycles | 5,000 | Cycles | Severe stress group |
| Tensile Bond Test Speed | 0.3 | mm/min | Crosshead speed for mechanical testing |
| Dentin Control Bond Strength (GP, 24h) | 14.14 (± 2.20) | MPa | Highest recorded control value |
| Dentin Lased Bond Strength (GP, 5000 cycles) | N/A (Destroyed) | MPa | Substrate failure prevented measurement |
| Dentin Altered Layer Thickness (Cited) | Approx. 10 | ”m | Thickness of laser-induced brittle layer |
| Bonding Area Diameter | 3 | mm | Standardized adhesion surface area |
Key Methodologies
Section titled âKey MethodologiesâThe experiment utilized precise material preparation and controlled thermal/mechanical stressing to evaluate adhesive performance:
- Substrate Preparation: Flat bovine enamel or dentin surfaces were prepared using a model trimmer and water-resistant polishing paper (#600).
- Laser Irradiation: Surfaces were uniformly irradiated with an Er:YAG laser (100mJ, 10pps) at a 0mm distance, perpendicular to the surface, and under water spray (implied for standard Er:YAG cutting). Non-irradiated specimens served as controls.
- Cavity Preparation (Microleakage Test): Saucer cavities (3mm length, 2mm width, 1.5mm depth) were prepared in human molars using a high-speed cutting diamond point. Internal walls were then uniformly irradiated with the Er:YAG laser.
- Adhesive Application: One-bottle, one-step bonding systems (G-BOND PLUS, CLEARFILÂź SBOND ND Plus, Scotchbond Universal Adhesive, BeautiBond Multi) were applied to the 3mm diameter bonding area.
- Curing and Storage: Composite resin was filled, and specimens were stored in 37°C distilled water for 24 hours.
- Thermal Stressing: Specimens were subjected to 2,000 or 5,000 thermocycles in water between 5°C and 55°C, with a 30s dwell time at each temperature.
- Mechanical Testing: Tensile bond strength was measured using a universal testing machine at a crosshead speed of 0.3 mm/min.
- Microleakage Evaluation: Dye penetration test using 0.5% basic fuchsin, followed by longitudinal cutting with a low-speed diamond saw and optical microscopy scoring (0 to 3).
6CCVD Solutions & Capabilities
Section titled â6CCVD Solutions & CapabilitiesâThe research demonstrates the extreme demands placed on materials used in high-precision dental and biomedical applications, particularly those involving high-energy lasers and severe thermal cycling. 6CCVD specializes in providing the stable, high-performance MPCVD diamond materials necessary to enable the next generation of these technologies.
Applicable Materials
Section titled âApplicable MaterialsâTo replicate or extend research involving high-power laser interaction, thermal stability, and precision machining, 6CCVD recommends the following materials:
- Optical Grade SCD (Single Crystal Diamond): Essential for Er:YAG laser optics (windows, prisms, beam splitters). SCD offers superior thermal conductivity (> 2000 W/mK) and ultra-low absorption, preventing the thermal lensing and instability observed in less robust materials, ensuring precise beam delivery (100mJ, 10pps).
- High-Wear PCD Substrates (Polycrystalline Diamond): Ideal for manufacturing the high-speed cutting diamond points and low-speed diamond saws used in the experimental preparation (e.g., cavity formation and specimen sectioning). PCD provides unmatched hardness and wear resistance for precision tooling.
- Electronic Grade SCD/PCD: Recommended for use as stable, inert platforms in advanced testing rigs (e.g., thermocycling baths or mechanical testing stages) where chemical inertness and dimensional stability under thermal stress (5°C to 55°C) are critical.
Customization Potential
Section titled âCustomization PotentialâThe study relies on highly specific dimensions (3mm bonding area, 1.5mm cavity depth) and precision cutting, directly aligning with 6CCVDâs core customization services:
| Research Requirement | 6CCVD Customization Service | Technical Specification |
|---|---|---|
| Precision Substrates: Need for flat, highly polished surfaces for bonding tests. | Advanced Polishing: Ultra-smooth surfaces for minimal scattering and controlled adhesion studies. | SCD: Ra < 1 nm. PCD: Ra < 5 nm (Inch-size). |
| Tooling Dimensions: Need for custom diamond cutting tools (points, saws). | Custom Dimensions & Shaping: Plates and wafers cut to exact specifications for tool fabrication. | Plates/Wafers up to 125mm (PCD). Substrates up to 10mm thick. |
| Sensor Integration: If future research requires electrical or thermal monitoring at the interface. | Internal Metalization Capability: Deposition of high-stability metals for contacts or thermal layers. | Au, Pt, Pd, Ti, W, Cu metalization available. |
Engineering Support
Section titled âEngineering SupportâThe observed failure of the adhesive interface on lased dentin is a complex material science problem involving thermal shock, micro-cracking, and chemical degradation. 6CCVDâs in-house PhD team specializes in analyzing material interactions under extreme conditions.
We offer consultation services to researchers and engineers working on similar Laser-Material Interaction and Biomedical Adhesion projects, assisting with:
- Selecting diamond materials for high-power laser optics to optimize beam quality and stability.
- Designing ultra-hard diamond tooling for precision micro-machining of brittle or hard materials.
- Developing stable diamond substrates for high-reliability testing platforms subject to severe thermal cycling.
For custom specifications or material consultation, visit 6ccvd.com or contact our engineering team directly. Global shipping (DDU default, DDP available) ensures rapid delivery of custom diamond solutions worldwide.
View Original Abstract
Various studies have revealed that the Er:YAG laser is effective in endodontic, periodontal and surgical treatments, and it is used in actual clinical practice. In particular, the Er:YAG laser shows excellent clinical effects when cutting hard tooth tissue, and there have been many studies on adhesive restoration involving teeth irradiated with Er:YAG laser. In this study, focusing on the one-bottle one-step bonding system, we performed tensile bond and marginal leakage tests to evaluate its adhesive properties to enamel and dentin irradiated with Er:YAG laser.Experiment 1Flat bovine enamel or dentin surfaces were prepared using a model trimmer and water-resistant polishing paper (#600), and were irradiated with Er:YAG laser (100mJ, 10pps). Non-irradiated specimens were used as a control. After bonding procedures were performed on these adherent surfaces of 3mm in diameter, the specimens were stored in 37°C distilled water for 24 hours, and were divided into two experimental groups: the 24-hour storage group and the thermal stress group. In the thermal stress group, the specimens were subjected to 2,000 or 5,000 thermocycling in water from 5°C to 55°C with a dwell time of 30s at each temperature. Thereafter, a tensile bond test was performed in each group (n = 10).Experiment 2Saucer cavities (3mm in length, 2mm in width, and 1.5mm in depth) in extracted human molars were prepared setting the anatomical cervical line as the center, using a high-speed cutting diamond point. The marginal line was placed in the enamel on the coronal side and in the dentin on the gingival side. After cavity preparation, the internal cavity walls were uniformly irradiated with Er:YAG laser (100mJ, 10pps). Non-irradiated specimens were used as a control (n = 10). After bonding and filling procedures, these specimens were stored in 37°C distilled water for 24 hours, and thermo-stressed after finishing and polishing. Then, the dye-penetration test was performed according to the following procedures. The root apex was sealed using glass-ionomer cement, and the tooth surface was fully coated with nail varnish except for the area approximately 1mm off the cavity margin. After immersion in 0.5% basic fuchsin at 37°C for 24 hours, each specimen was cut longitudinally at the center of the cavity using a low-speed diamond saw. The degree of dye penetration into the coronal (enamel) or cervical (dentin) wall was evaluated by optical microscopy.From these experiments, the following conclusions were obtained:1. In the tensile bond test, the lased dentin exhibited lower bond strength than the non-irradiated dentin, while enamel showed almost the same bond strength regardless of the laser irradiation.2. In the dye penetration test, marginal microleakage was observed in the dentin cavity wall, whereas good marginal integrity was demonstrated at the enamel margin.