This study investigated the effects of thermally induced stresses (thermocycling) on the shear bond strength of resin-modified, chemically cured, glass ionomer cement for use as an orthodontic bonding agent. A conventional no-mix composite resin was also used as a control. Mesh-based metal orthodontic brackets were bonded to extracted human premolars using either the resin-modified glass ionomer cement or the no-mix composite resin. Specimens were stored either in water at 37 degrees C for 24 hours for baseline data or thermocycled between 5 degrees C and 55 degrees C for 200 and 20,000 cycles before testing the in vitro shear bond strengths. Thermocycling reduced shear bond strengths for all specimens. The resin-modified glass ionomer cement showed a 11.1% decrease after 200 thermocycles and 26.5% decrease after 20,000 thermocycles, whereas the no-mix adhesive resin showed only 5.7% and 17.9% reductions, respectively. Analysis of variance showed statistically significant differences between the mean shear bond strengths of the groups at the P < .001 level of significance. For the resin-modified glass ionomer cement groups, the predominant bond failure site was at the bracket-adhesive interface. The results of this study suggest strongly that resin-modified glass ionomer cements offer a viable alternative to conventional no-mix composite resins, with satisfactory in vitro shear bond strength even after 20,000 thermocycles.
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http://dx.doi.org/10.1043/0003-3219(2003)073<0692:EOTOTB>2.0.CO;2 | DOI Listing |
Purpose: To make micro-CT comparison and evaluation of sealant penetration depth in different types of fissures after heating of the material or application of vibrations.
Materials And Methods: One hundred sound third molars have been sealed as follows: group 1 (n = 20), light-cured resin sealant at room temperature, group 2 (n = 20), light-cured resin sealant, preheated to 41.0°C, group 3 (n = 20), light-cured resin sealant, preheated to 51.
Photobiomodul Photomed Laser Surg
January 2025
Department of Preventive Dental Sciences, College of Dentistry, Dar Al Uloom University, Riyadh, Saudi Arabia.
Impact of surface conditioner phytic acid (IP6) Er,Cr:YSGG laser (ECYL) methylene blue photodynamic therapy (MB-PDT) on the microleakage and shear bond strength (SBS) of resin-modified glass ionomer cement (RMGIC) to primary sound dentin. Overall, 80 extracted sound primary molars were collected followed by their submergence in self-cure acrylic resin. The dentin surface was exposed and made flat and was assigned into four groups based on the surface conditioning.
View Article and Find Full Text PDFJ Esthet Restor Dent
January 2025
Operative Department, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
Objective: To investigate the effect of cervical margin relocation with four different injectable restorative materials on the fracture resistance of molars receiving mesio-occluso-distal CAD/CAM nanoceramic onlay restorations.
Materials And Methods: One hundred and five sound mandibular molars received a standardized mesio-occluso-distal onlay preparation, with cervical margins located 2 mm apical to the cemento-enamel junction. The molars were randomly allocated into five groups (n = 21) according to the cervical relocating materials used: Group I had no cervical margin relocation; Group II used a highly viscous glass ionomer; Group III used a highly-filled injectable resin composite; Group IV used a resin-modified glass ionomer; and Group V used a bioactive ionic resin.
BMC Oral Health
January 2025
Faculty of Dentistry, Department of Endodontics, Ondokuz Mayis University, Samsun, Kurupelit, 55139, Turkey.
Background: The aim was to evaluate the stresses in teeth, with external root resorption (ERR) restored with different materials using finite element analysis (FEA).
Methods: In this study, a Micro-CT scan was conducted on a prepared maxillary central tooth. DICOM-compatible images obtained from the sections were converted into stereolithography format using Ctan software.
Sci Rep
January 2025
Department of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, 600077, India.
Polydopamine (PD), inspired by the wet adhesion mechanism of mussel foot proteins, has emerged as a promising adhesive material with wide-ranging applications. This study aimed to compare the adhesive properties of PD and Glass Ionomer Cement (GIC) on enamel and dentin substrates, evaluating PD's potential as an alternative adhesive in dental practice. A total of 120 human premolars were prepared, with 80 teeth allocated for Scanning Electron Microscopy (SEM) analysis and 40 teeth reserved for shear bond strength testing.
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