Effect of Alternative Self-Etch Applications on Dentin Bond Strength of “No Wait Concept” Universal Adhesives
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2021-02-15 |
| Journal | Odovtos - International Journal of Dental Sciences |
| Authors | Tuğba SERİN KALAY, Beyza Zaim |
| Institutions | Karadeniz Technical University |
| Citations | 4 |
| Analysis | Full AI Review Included |
Executive Summary
Section titled “Executive Summary”This study evaluates the mechanical performance (microtensile bond strength, µTBS) of three “no wait concept” universal dental adhesives when applied using alternative self-etch protocols on dentin substrates.
- Objective: Determine the effect of application time (Immediate, Prolonged Wait, Active Rubbing) on the resin-dentin bond strength of three commercial multi-mode adhesives: Clearfil Universal Bond Quick (CUQ), G-Premio Bond (GPB), and Tokuyama Universal Bond (TUB).
- Key Finding on “No Wait”: The manufacturer-recommended “Immediate Application” (IA) procedure resulted in the lowest µTBS values across all tested adhesives, rejecting the null hypothesis.
- Performance Enhancement: Prolonged application time (PA, 10-second wait) significantly increased µTBS for all adhesives compared to IA (p < 0.05), attributed to increased monomer infiltration and solvent evaporation.
- Active Application (AA) Success: Active rubbing (AA, 10 seconds) significantly increased µTBS for the light-cured adhesives (CUQ and GPB), with GPB achieving the highest overall mean strength (23.11 MPa).
- Self-Curing Limitation: The self-curing adhesive (TUB) exhibited a significantly lower µTBS under active application (11.97 MPa), suggesting that the rubbing action negatively interferes with its chemical polymerization process (Borate Catalyst/3D-SR technology).
- Material Chemistry Impact: Higher bond strengths in CUQ and GPB are linked to the presence of the 10-methacryloyloxydecyl dihydrogen phosphate (MDP) monomer, which forms stable ionic bonds with dentin calcium.
Technical Specifications
Section titled “Technical Specifications”| Parameter | Value | Unit | Context |
|---|---|---|---|
| Test Type | Microtensile Bond Strength (µTBS) | MPa | Mechanical performance metric |
| Highest Mean µTBS (GPB, AA) | 23.11 ± 6.30 | MPa | G-Premio Bond, Active Application/Rubbing |
| Lowest Mean µTBS (TUB, AA) | 11.97 ± 2.69 | MPa | Tokuyama Universal Bond, Active Application/Rubbing |
| Dentin Surface Preparation | 600-grit | SiC paper | Standardized smear layer creation |
| Specimen Cross-Section | 1 | mm2 | Area subjected to tensile force |
| Tensile Test Speed | 1 | mm/min | Crosshead speed during mechanical testing |
| Storage Condition | 37 | °C | Distilled water, 24 hours post-bonding |
| CUQ pH | 2.3 | N/A | Clearfil Universal Bond Quick (Ethanol/Water solvent) |
| GPB pH | 1.5 | N/A | G-Premio Bond (Acetone solvent) |
| TUB pH | 2.2 | N/A | Tokuyama Universal Bond (Isopropyl Alcohol solvent) |
| Key Monomers (CUQ, GPB) | 10-MDP | N/A | Monomer responsible for chemical bonding to HAp |
Key Methodologies
Section titled “Key Methodologies”The study utilized extracted, non-carious human third molars prepared to expose mid-coronal dentin surfaces standardized with 600-grit SiC paper.
- Specimen Preparation: Teeth were embedded in self-curing acrylic resin. The occlusal third was removed using a low-speed diamond saw under running water to expose dentin.
- Adhesive Grouping: Twenty-seven teeth were divided into three main groups based on the adhesive used:
- Clearfil Universal Bond Quick (CUQ, Kuraray Noritake)
- G-Premio Bond (GPB, GC Corp)
- Tokuyama Universal Bond (TUB, Tokuyama Dental)
- Application Protocols (Subgroups, n=3 teeth per subgroup):
- IA (Immediate Application): Adhesive applied and immediately subjected to air-dry according to manufacturer instructions (e.g., medium air-dry for 5s for CUQ).
- PA (Prolonged Application): Adhesive applied followed by a 10-second wait before air-drying.
- AA (Active Application/Rubbing): Adhesive applied and rubbed onto the dentin surface for 10 seconds before air-drying.
- Restoration and Curing: Two layers of 2-mm thick composite resin (Filtek Z250) were applied and cured using a LED light-curing unit (Elipar S10).
- Sectioning and Testing: After 24 hours of storage in 37°C distilled water, bonded teeth were cut into 1 mm2 sections (n=15 sections tested per subgroup). Sections were subjected to tensile force at a crosshead speed of 1 mm/min.
- Failure Analysis: Fracture surfaces were examined under a stereomicroscope and classified as adhesive, cohesive in composite, or mixed failure.
Commercial Applications
Section titled “Commercial Applications”This research directly impacts the formulation, instruction, and clinical use of multi-mode dental adhesives, focusing on optimizing mechanical performance in restorative procedures.
- Dental Materials Manufacturing: Provides data necessary for manufacturers to revise application instructions for “no wait” adhesives, emphasizing the need for prolonged application or active rubbing to maximize bond strength.
- Biomaterials Science: Focuses on the interaction between functional monomers (like MDP) and dentin structure, particularly how solvent type (acetone vs. ethanol vs. isopropyl alcohol) and mechanical agitation affect infiltration and polymerization kinetics.
- Restorative Dentistry: Directly informs clinical protocols for placing composite restorations, ensuring long-term mechanical stability and reducing the risk of restoration failure due to inadequate dentin bonding.
- Quality Control and Testing: Utilizes and validates the microtensile bond strength (µTBS) test as a critical metric for evaluating the mechanical integrity of the resin-dentin interface.
View Original Abstract
Objective: This study evaluated the effects of alternative self-etch application modes on resin-dentin microtensile bond strength (µTBS) of three commercially available “no wait” concept universal adhesives. Materials and methods: In this study extracted impacted non-carious human third molars were used. The flat surfaces were prepared in mid-coronal dentin and prepared with a 600-grit SiC paper. The three universal adhesives that were used are as follows: Clearfil Universal Bond Quick (CUQ, Kuraray Noritake, Japan), G-Premio Bond (GPB, GC Corp, Japan), and a self-curing universal adhesive “Tokuyama Universal Bond” (TUB; Tokuyama Dental, Japan). The following three different application procedures were used for the dentin surfaces: the adhesives were applied and immediately subjected to air-dry; the adhesives were applied followed by a 10-second wait; or the adhesives were rubbed for 10 seconds. Then composite resin was applied to the dentin surface and light cured. After storage in 37°C distilled water for 24 h, all the bonded teeth were cut into 1mm² sections using a low-speed diamond saw (Micracut 125 Low Speed Precision Cutter, Metkon, Bursa, Turkey) under running water (n=15). The sections were subjected to a tensile force at a crosshead speed of 1mm/min in a testing apparatus (Microtensile Tester, Bisco, IL, USA) and µTBS values were measured. Data were analyzed using the Kruskal-Wallis test and Mann-Whitney U test. Failure modes were analyzed under a stereomicroscope. Results: Prolonged application time significantly affected the µTBS (p<0.005). A significant increase of µTBS on active application was observed for CUQ and GPB. The TUB with an active application had a significantly lower µTBS value compared with the other adhesives. Conclusions: Prolonged application time caused significant improvement of bond strength in all adhesives. The active application is effective at increasing the dentin bond strength except for TUB.