Purpose: The aim of this study was to evaluate the effect of six different surface conditioning methods on the shear bond strength of ceramic brackets bonded to feldspathic porcelain.
Materials And Methods: A total of 60 feldspathic porcelain disks were fabricated and divided into six subgroups including 10 specimens in each. Specimens were first treated one of the following surface conditioning methods, namely, 37% phosphoric acid (G-H3PO4), 9.4% hydrofluoric acid (G-HF), grinding with diamond burs (G-Grinding), Nd:YAG laser (G-Nd:YAG), Airborne-particle abrasion (G-Abrasion). Specimens were also coated with silane without surface treatment for comparison (G-Untreated). A total of 60 ceramic brackets were bonded to porcelain surfaces with a composite resin and then subjected to thermocycling 2500× between 5°C and 55°C. The shear bond strength test was carried out using a universal testing device at a crosshead speed of 0.5 mm/min. Failure types were classified according to the adhesive remnant index. Analysis of variance and Tukey tests were used for statistical analysis (α = 0.05). Microstructure of untreated and surface-treated specimens was investigated by scanning electron microscopy.
Results: Using G-Abrasion specimens resulted in the highest shear bond strength value of 8.58 MPa for feldspathic porcelain. However, the other specimens showed lower values: G-Grinding (6.51 MPa), G-Nd:YAG laser (3.37 MPa), G-HF (2.71 MPa), G-HPO (1.17 MPa), and G-Untreated (0.93 MPa).
Conclusion: Airborne-particle abrasion and grinding can be used as surface treatment techniques on the porcelain surface for a durable bond strength. Hydrofluoric acid and phosphoric acid etching methods were not convenient as surface treatment methods for the feldspathic porcelain.
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http://dx.doi.org/10.1177/0391398818756181 | DOI Listing |
J Phys Chem A
January 2025
Shandong Province Key Laboratory of Medical Physics and Image Processing Technology, School of Physics and Electronics, Shandong Normal University, Jinan 250014, China.
The strategy of designing efficient room-temperature phosphorescence (RTP) emitters based on hydrogen bond interactions has attracted great attention in recent years. However, the regulation mechanism of the hydrogen bond on the RTP property remains unclear, and corresponding theoretical investigations are highly desired. Herein, the structure-property relationship and the internal mechanism of the hydrogen bond effect in regulating the RTP property are studied through the combination of quantum mechanics and molecular mechanics methods (QM/MM) coupled with the thermal vibration correlation function method.
View Article and Find Full Text PDFJ Phys Chem A
January 2025
Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China.
This study investigates the equilibrium geometries of four different Se isomers using the coupled cluster single and double perturbative (CCSD(T)) method, extrapolating to the complete basis sets. The ground-state geometry of the Se isomer with the C structure (2.8715 Å, 2.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Pediatric Dentistry Faculty of Dental Medicine, University of Damascus, Damascus, Syria.
This in vitro study aims to evaluate various surface treatments on the shear bond strength and failure mode of CAD/CAM PMMA teeth to the heat-polymerized acrylic denture base. The study sample consisted of 100 teeth that were divided equally into five groups: Group 1: denture artificial teeth (control), Group 2: PMMA teeth without surface treatment, Group 3: PMMA teeth with MMA etching, Group 4: PMMA teeth with sandblasting (aluminum oxide particles), and Group 5: PMMA teeth with perpendicular grooves. The shear bond strength test was performed using a universal testing machine and the failure mode was recorded.
View Article and Find Full Text PDFAAPS PharmSciTech
January 2025
Xiangya School of Pharmaceutical Science, Central South University, Changsha, 410006, Hunan, China.
Acrylic pressure-sensitive adhesives (PSAs) are widely applied in transdermal drug delivery systems (TDDS). However, the molecular mechanisms underlying the effect of functional groups of PSAs on drug release and transdermal permeation properties remain insufficiently clear. In this study, we investigated the effect of acrylic PSAs' functional groups on the in vitro release and transdermal permeation properties of a model drug guanfacine (GFC).
View Article and Find Full Text PDFJ Prosthodont Res
January 2025
Institute of Dentistry, Department of Biomaterials Science and Turku Clinical Biomaterials Centre - TCBC, Turku, Finland.
Purpose: This study investigated the bond strength between short fiber-reinforced resin composite (SFC) and dentin following air abrasion with various types of abrasive particles.
Methods: A total of 120 human molars were prepared for a shear bond strength (SBS) test of the resin composite. The teeth were divided into 12 groups (n = 10/group) based on the air abrasion particle used.
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