Objectives: The purpose of this study was to simultaneously determine the impact of exposure times and incremental resin composite overlaying thickness on the cure kinetics of a light activated composite and a dentin adhesive at selected depths of a simulated restoration.
Methods: Levels and kinetics of polymerization of a light activated resin composite (Z250, 3M-ESPE) and dentin adhesive (Excite, Ivoclar) cured with a halogen light unit (Demetron, Kerr, USA) operating at low/medium intensity (500 mW/cm2) for different exposure durations (20 and 60 s) were measured at selected depths (0.3, 0.6 and 1mm) using a modified calorimetric analyzer (DSC 25, METLLER-TOLEDO).
Results: Final polymerization levels of materials up to 1mm through the composite are not significantly different while the light shielding effect of incremental resin composite overlaying progressively reduces their reaction rates.
Significance: Prolonged irradiation time at low/medium energies is effective for proper conversion of a resin composite and dentin adhesive; 60 s irradiation time provides the maximum obtainable conversion through the dental resin composite for thicknesses up to 1mm.
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http://dx.doi.org/10.1016/j.dental.2004.09.012 | DOI Listing |
Syst Rev
January 2025
Conservative Dentistry Department, Faculty of Dentistry, Mansoura University, Mansoura, Postal Code, 35516, Egypt.
Background: Hydrophilic monomer 2-hydroxyethyl methacrylate (HEMA)-free adhesive systems are gaining increasing popularity nowadays. Although the addition of HEMA to dental adhesives improves dentin wettability and resin diffusion into demineralized collagen fibrils, HEMA's high hydrophilicity can lead to hydrolytic degradation of the adhesive interface. Thus, HEMA-free adhesive systems have been developed.
View Article and Find Full Text PDFInt Dent J
January 2025
Biomaterials Science, Division of Dentistry, School of Medical Sciences, University of Manchester, Manchester, UK.
Introduction And Aims: This study aimed to investigate the efficacy of 3 bleaching methods on stained polymer-based CAD/CAM blocks in terms of surface roughness, hardness stability, discolouration reduction and susceptibility to re-staining following bleaching.
Methods: Two-mm-thick slabs (N = 128) were prepared from CeraSmart (CS), Grandio Blocs (GB), Vita Enamic (VE), and direct resin composite GrandioSO (RC). Coffee-stained specimens (n = 8) were subdivided into bleaching (BL) groups: in-office bleaching (OB), home bleaching (HB), whitening mouthwash (MW), and a control group with 14-day storage in water (CL).
Sci Rep
January 2025
Stomatology Hospital, School of Stomatology, Zhejiang University School of Medicine, Hangzhou, 310000, China.
Direct resin restoration has been widely used to restore the tooth defect for its convenience and minimal invasion. However, the accuracy of the final contour of class II restoration is often unpredictable and quite technique-sensitive due to the limitation of traditional matrix band system. In this study, the authors developed a novel matrix band system using shape memory polymer (SMP), which possessed two reversible shapes including digitized permanent shape to reproduce anatomical proximal contour and programmable temporary shape for clinical practice and reservation.
View Article and Find Full Text PDFJ Dent
January 2025
State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, Key Laboratory of Oral Biomedicine Ministry of Education, Hubei Key Laboratory of Stomatology, School & Hospital of Stomatology, Wuhan University, Wuhan 430079, China. Electronic address:
Objectives: Highly translucent yttria-stabilized zirconia (YSZ) has become more popular due to its enhanced aesthetics. This study aimed to evaluate the influence of traditional air abrasion and a new etching and cleaning agent, Multi Etchant, on the mechanical performance, optical properties, and bond strength of highly translucent zirconia.
Methods: Specimens of 6YSZ, 5YSZ, 4YSZ&5YSZ, and conventional 3YSZ were fabricated and underwent different surface treatments, including as milled, air abrasion, and Multi Etchant.
J 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.
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