Showing papers in "Dental Materials in 1993"

TL;DR: The effect of mixing-in of porosity slowed down and decreased the shrinkage stress development of light-initiated composites, and trying to find a comprehensive explanation for the differences in behavior of stress development in LC and CC composites was investigated.

TL;DR: The linometer offers an easy means for routine polymerization shrinkage determinations and therefore may be useful in evaluating new monomer systems for dental composites.

TL;DR: In vitro bond strengths of human enamel and dentin treated with five contaminants were measured and may be less sensitive to common forms of contamination than typically assumed.

TL;DR: The half-life of radicals in a light-cured inlay composite was determined at different temperatures, and the influence of different fillers and filler amounts on the stability of these radicals in light- cured experimental composites was investigated.

TL;DR: Light-activated cements were found to have a potential for releasing fluoride equivalent to that of conventional cements, and the amount and rate of release varied among cements.

TL;DR: Clinically, ultrasonic cleaning of sandblasted and tribochemically silica-coated alloys might improve resin bonding as loose surface particles are removed without relevant changes in composition.

TL;DR: It was concluded that maintaining a constant temperature environment (+ or - 0.02 degrees C) for the dilatometer during the shrinkage test was the most critical factor for successful application of the Dilatometer.

TL;DR: This study examined the effect of cavity size, hydration conditions and type of composite on cusp movement following placement of MOD composite restorations in vitro to observe differences in deflection of cusps with two different restorative materials.

TL;DR: It is indicated that saline, the most commonly used solution in dental materials research, may be unsuitable for use as a result of its effect on dentin permeability and bond strength.

TL;DR: A newly developed incremental mixing technique has been used to incorporate over 30 vol % chopped high performance polyethylene fiber into acrylic denture base resin that produced a substantial improvement in stiffness and impact strength and the mechanical properties were insensitive to notches that mimic anatomical features.

TL;DR: In this article, the authors used FT-Raman scattering to determine the degree of conversion of dental resins using linear calibration curves for the aromatic mixtures Bis-GMA/TEGDMA and Bisphenol-A/BEGDAMA using C = C/phi, and for the wholly aliphatic mixture EGDMA/EGDA using C= C/C = O.

TL;DR: The results from this study imply that glass ionomer restorations may act as intraoral devices for the controlled slow release of fluoride at sites at risk for recurrent caries.

TL;DR: Atomic force microscopy (AFM) was used in the examination of the early stages of acid treatment of dentin and appears to hold exceptional promise for the study of conditioning and priming agents for dentin bonding.

TL;DR: The shear bond strength of four dentin bonding systems which remove or modify the smear layer were measured in vivo in dog canine and molar teeth as a function of dentin depth.

TL;DR: Investigating the effect of different storage media on microleakage at the gingival margin of mixed Class V composite restorations found extracted teeth assigned for in vitro evaluation of dentin bonding agents should not be stored in formalin, probably a result of collagen cross-linking by formaldehyde.

TL;DR: The results suggest that crack-bridging is the most likely mechanism for the strengthening of ceramic dental restorations through surface treatments and cement coatings of the fracture-initiating surface.

TL;DR: It was found that 9 wt% microfiller loading produced the highest mean fracture toughness and the diametral tensile strength displayed only small differences for the range of microfilling content studied with mean values ranging from 42.1-49.6 MPa.

TL;DR: It can be assumed that both methods of welding are suitable for welding titanium, because laser welding is the more suitable technique in dentistry because of its lower thermal alteration of the workpieces.

TL;DR: The present study focused on the effects of argon pressure, mold venting, and investment permeability on the mold filling of titanium and the soundness of titanium castings.

TL;DR: It was found that not only were the Cr and Mo content of the alloys important for corrosion resistance, but the composition of the surface oxide as well was important as well.

TL;DR: The feasibility of preparing several new types of dental cements based on the interaction of water-soluble polymers with a self-setting calcium phosphate powder mixture is demonstrated.

TL;DR: The objective of this work was to develop copolymers of alicyclic spiroorthocarbonates and epoxies that would yield hard non-shrinking matrix resins suitable for formulating dental composites.

TL;DR: The influence of varying concentrations of two amine reducing agents commonly used in commercial light-cured composites, N,N-dimethyl-p-toluidine (DMPT) and 2-dimethylamino)ethyl methacrylate (DMAEMA), on the degree of conversion (DC), Knoop hardness, and compressive and transverse strengths of an unfilled light-Cured resin was investigated.

TL;DR: The effect of home-use topical fluorides on the surface integrity of two glass ionomers and a composite was studied using SEM and it was found that the APF and the non-proprietary gel had a significant effect on both Gl matrix and particles and on the composite particles.

TL;DR: The present study compared the compressive, tensile and flexural strengths of 26 commercial glass ionomer cements, which were evaluated 24 h after the beginning of the setting reaction in order to give a global estimation of their overall strength.

TL;DR: The purpose of the study reported here was to evaluate the fatigue parameters of a model experimental porcelain using dynamic fatigue testing, which makes use of several constant stressing rates to perform strength tests.

TL;DR: A new technique using standardized test facings was designed to evaluate interdental plaque accumulation on different restoration materials, and both ceramics and a bonding composite showed no significant differences compared to the natural tooth substance.

TL;DR: The results of the present study suggest that active prepolymerized primers may provide significant advantages over two-component systems in the repair of Ni-Cr porcelain fractures involving removal of the metal oxide layer.

TL;DR: The intermediate layer between a glass ionomer restoration and dentin was examined morphologically by scanning electron microscopy and Fourier transform infrared spectroscopy and showed that the intermediate layer is composed primarily of mineral fluoridated carbonatoapatite.

TL;DR: In this article, the in vitro performance of three visible light-cured glass ionomer liners with 2-HEMA was analyzed and significant correlations were detected between the optical properties of the liners and the top-bottom differences in the extent of conversion, as well as between the maximum marginal gap at the dentin/liner interface and the bond strength with dentin and composite.