Novel fluoride rechargeable dental composites containing MgAl and CaAl layered double hydroxide (LDH).

Objective: This study aims to incorporate 2:1 MgAl and 2:1 CaAl layered double hydroxides (LDHs) in experimental dental-composites to render them fluoride rechargeable. The effect of LDH on fluoride absorption and release, and their physico-mechanical properties are investigated.

Methods: 2:1 CaAl and 2:1 MgAl LDH-composite discs prepared with 0, 10 and 30wt% LDH were charged with fluoride (48h) and transferred to deionized water (DW)/artificial saliva (AS).

Layered Double Hydroxide Fluoride Release in Dental Applications: A Systematic Review.

This systematic review appraises studies conducted with layered double hydroxides (LDHs) for fluoride release in dentistry. LDH has been used as antacids, water purification in removing excess fluoride in drinking water and drug delivery. It has great potential for controlled fluoride release in dentistry, e.

Development of a novel bioactive glass for air-abrasion to selectively remove orthodontic adhesives.

Objectives: To develop a novel, bioactive glass for removing residual orthodontic adhesive via air-abrasion, following bracket debonding, and to evaluate its effectiveness against a proprietary bioactive glass 45S5(Sylc™)-air-abrasion, and a slow-speed tungsten carbide (TC) bur.

Materials And Methods: Three glasses were prepared and their bioactivity was proved. One novel glass (QMAT3) was selected due to its appropriate hardness, lower than that of enamel/45S5(Sylc™).

The properties of experimental resin-modified glass-ionomer luting cements (RMGICs) containing novel monomers.

Objectives: To investigate working and setting times, compressive fracture strength (CFS), compressive modulus (CM), three-point flexure strength (TFS) and tensile flexure modulus (TFM) of commercial, control and experimental RMGICs.

Methods: RelyX Luting (RX, 3M-ESPE) and Fuji Plus (FP, GC), two control home liquids and eight new liquid compositions (F1-F4 and R1-R4) comprising different percentages of the monomer HPM (hydroxypropyl-methacrylate) and/or THFM (tetrahydrofurfuryl-methacrylate) with the original monomer HEMA (2-hydroxyethyl-methacrylate) were used in this study. The polymerization was initiated chemically (using benzene sulfonic acid sodium-salt in FP powder and potassium persulfate/ascorbic acid in RX powder).

The effect of bioactive glasses on enamel remineralization: A systematic review.

Introduction/objectives: To evaluate the effectiveness of bioactive glasses in promoting enamel remineralization.

Data: An electronic search with a complementary gray literature search for in vivo and in vitro research. No language restrictions were applied.

Development of experimental resin modified glass ionomer cements (RMGICs) with reduced water uptake and dimensional change.

Objective: To investigate water uptake, desorption, diffusion coefficient, solubility and dimensional changes of four experimental RMGICs in deionized water (DW) and artificial saliva (AS), and compare with two commercial RMGICs and control home liquids based on the two commercial materials used.

Methods: Two commercial RMGICs, RelyX Luting (RX, 3M ESPE) and Fuji Plus (FP, GC), two control home liquids and four new liquid compositions (F1, F2, R1, R2) comprising different percentages of the monomer THFM (tetrahydrofurfuryl-methacrylate) with the original monomer HEMA (2-hydroxyethyl-methacrylate) were used in this study. Home and experimental liquids were mixed with the corresponding commercial powder.

A study to investigate and compare the physicomechanical properties of experimental and commercial temporary crown and bridge materials.

Objectives: To develop two experimental temporary crown and bridge materials with improved physicomechanical properties.

Methods: Commercial materials: Trim (TR, monomethacrylate, Bosworth) and Quicktemp2 (QT, dimethacrylate, Schottlander).

Experimental Materials: isobutyl methacrylate/poly(ethyl methacrylate) (IBMA/PEM) and n-butyl methacrylate/PEM (nBMA/PEM), both monomethacrylates.

Delivery of macromolecules across oral mucosa from polymeric hydrogels is enhanced by electrophoresis (iontophoresis).

Objective: To develop polymeric hydrogel delivery systems for iontophorseis transfer of large molecules across buccal (porcine) mucosa.

Methods: Three hydrogels (PVA, HPMC and PVA/HPMC) were prepared as stable gels (7 mm diameter/1.5 mm thick).

Electrically induced transport of macromolecules through oral buccal mucosa.

Objective: To investigate the feasibility of iontophoretic delivery of large molecules across buccal mucosa, and to establish its potential for enhanced drug delivery.

Methods: Qualitative (6h) and quantitative (8 and 36 h) assessment of porcine buccal mucosa, using a diffusion cell in vitro model, was carried out by fluorescent microscopy and UV/Vis spectroscopy respectively, with four fluorescently-labeled model species (3 and 10 kDa dextrans, 12 kDa parvalbumin and 66 kDa bovine serum albumin, BSA). Passive and iontophoresis parameters were obtained.

Some aspects of the formulation of alginate dental impression materials--setting characteristics and mechanical properties.

Objective: To study the role of the various components of alginate dental impression materials.

Methods: Experimental materials were formulated and their physical properties characterized and compared to commercially available counterparts (Neocolloid, Palgat Plus and Blueprint Cremix). Properties examined were: dimensional stability and weight change in water and artificial saliva; setting behavior; Shore A hardness and tear energy.

The effect of disinfecting solutions on the dimensional stability of dental alginate impression materials.

Objectives: Dimensional changes occur in set dental alginate impression materials when immersed in disinfecting solutions. In this contribution the dimensional changes of two alginates in two disinfecting solutions, and for two specimen thicknesses, have been studied. The results were analyzed theoretically.

An experimental and theoretical study of the effect of sample thickness on the Shore hardness of elastomers.

Objective: The Shore hardness test is a quick and convenient way to measure hardness of elastomers. The test specifies that the specimen should be at least 6mm thick; however, published work in the literature indicates that workers often use much thinner samples. The aim of this study was to investigate the effect of thickness on the measured hardness of a range of dental elastomers and develop a theoretical relationship to predict the effect.

The relationship between Shore hardness of elastomeric dental materials and Young's modulus.

Objectives: Hardness of elastomers can be directly related to Young's modulus, a relationship that was investigated in detail by Gent in a paper in 1958. The aim of this study was to test this relationship for 13 dental elastomers (12 silicone and 1 polyether) using the equation derived by Gent and one from BS 903 (1950) that accounts for departures at low values.

Methods: The dental elastomers were subjected to tensile testing and Shore A scale hardness measurements.

NMR imaging of the diffusion of water at 310 K into semi-IPNs of PEM and poly(HEMA-co-THFMA) with and without chlorhexidine diacetate.

Magnetic resonance imaging has been used to monitor the diffusion of water at 310 K into a series of semi-IPNs of poly(ethyl methacrylate), PEM, and copolymers of 2-hydroxyethyl methacrylate, HEMA, and tetrahydrofurfuryl methacrylate, THFMA. The diffusion was found to be well described by a Fickian kinetic model in the early stages of the water sorption process, and the diffusion coefficients were found to be slightly smaller than those for the copolymers of HEMA and THFMA, P(HEMA-co-THFMA), containing the same mole fraction of HEMA in the matrix. A second stage sorption process was identified in the later stage of water sorption by the PEM/PTHFMA semi-IPN and for the systems containing a P(HEMA-co-THFMA) component with a mole fraction HEMA of 0.