Large-Scale Fabrication of Boron Nitride Nanosheets and Their Utilization in Polymeric Composites with Improved Thermal and Mechanical Properties

Oral surgery, oral medicine, oral pathology, oral radiology and endodontics

Metal‐Based Nanomaterials in Biomedical Applications: Antimicrobial Activity and Cytotoxicity Aspects

Strategies to prevent hydrolytic degradation of the hybrid layer—A review

The sol-gel process

/pdf/errors-in-light-emitting-diodes-positioning-when-curing-bulk-1qlmycxu3k.pdf

Errors in light-emitting diodes positioning when curing bulk fill and incremental composites: impact on properties after aging

Avaliação da dureza superficial de cimentos resinosos após cimentação de pinos de fibra de vidro

Physicochemical and biological properties of experimental dental adhesives doped with a guanidine-based polymer: an in vitro study

The aim of this study was to evaluate the effect of a light source on nanohardness, elastic modulus, water sorption and solubility of a composite resin. Four curing units were used, three of which had an LED and another had a halogen source. The resin composite Z250 (3M ESPE) was used for all tests. For water sorption and solubility, five resin disks were made (15 mm in diameter and 1 mm thick), and these were polymerized for 20 seconds at nine different points (1 in the center and 8 around). For nanohardness and elastic modulus evaluation, 20 cylinders (5 for each group) were made with a bipartite steel matrix (6.0 mm diameter and 4.0 mm thick). The results of this study showed that the group polymerized with the Radii light-curing unit presented less water sorption than other curing units (p < 0.05). No statistical difference between units was found in nanohardness in 1mm-thick specimens. However, decreased nanohardness was shown at higher resin composite depth (p < 0.05). A Pearson correlation showed a strong positive relationship between nanohardness and elastic modulus for all groups and depths. The light source affects the water sorption, nanohardness and elastic modulus of composite resins.

/pdf/effect-of-light-sources-on-nanohardness-elastic-modulus-and-43q0phwq0g.pdf

Effect of light sources on nanohardness, elastic modulus and water sorption of a composite resin

Fixed orthodontic appliances may lead to biofilm accumulation around them that may increase caries risk. This study aimed to evaluate the influence of quaternary ammonium methacrylates (QAMs) on the physicochemical properties, cytotoxicity, and antibacterial activity of adhesive resins for orthodontic purposes. Methodology: A base resin was prepared with a comonomer blend and photoinitiator/co-initiator system. Two different QAMs were added to the base adhesive: dimethylaminododecyl methacrylate at 5 wt.% (DMADDM) or dimethylaminohexadecyl methacrylate (DMAHDM) at 10 wt.%. The base adhesive, without QAMs, (GC) and the commercial Transbond™ XT Primer 3M (GT) were used as control. The resins were tested immediately and after six months of aging in the water regarding the antibacterial activity and shear bond strength (SBS). The antibacterial activity was tested against Streptococcus mutans via metabolic activity assay (MTT test). The groups were also tested for the degree of conversion (DC) and cytotoxicity against keratinocytes. Results: The resins containing QAM showed antibacterial activity compared to the commercial material by immediately reducing the metabolic activity by about 60%. However, the antibacterial activity decreased after aging (p 0.05) and DC (p>0.05). The incorporation of DMADDM and DMAHDM significantly reduced the keratinocyte viability compared to the GT and GC groups (p<0.05). Conclusion: Both adhesives with QAMs showed a significant reduction in bacterial metabolic activity, but this effect decreased after water aging. Lower cell viability was observed for the group with the longer alkyl chain-QAM, without significant differences for the bonding ability and degree of conversion. The addition of QAMs in adhesives may affect the keratinocytes viability, and the aging effects maybe decrease the bacterial activity of QAM-doped materials.

/pdf/physicochemical-properties-and-biological-effects-of-505rlm2zfh.pdf

Physicochemical properties and biological effects of quaternary ammonium methacrylates in an experimental adhesive resin for bonding orthodontic brackets.

Fabrício Mezzomo Collares

Papers

Errors in light-emitting diodes positioning when curing bulk fill and incremental composites: impact on properties after aging

Avaliação da dureza superficial de cimentos resinosos após cimentação de pinos de fibra de vidro

Physicochemical and biological properties of experimental dental adhesives doped with a guanidine-based polymer: an in vitro study

Effect of light sources on nanohardness, elastic modulus and water sorption of a composite resin

Physicochemical properties and biological effects of quaternary ammonium methacrylates in an experimental adhesive resin for bonding orthodontic brackets.