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Biomedical subjects

E C Combe

Publications and source records attributed to E C Combe.

At least 91 records · Page 5Linked to original sources
PubMed1981

Reaction of the exposed pulps to new cements containing calcium hydroxide.

The biologic properties of three newly developed cements containing calcium hydroxide were evaluated and compared with those of polycarboxylate cement and Dycal by application of the cements in direct contact with rat pulps. The newly developed cements were biologically acceptable and induced pulpal healing by formation of secondary dentin. Dycal elicited mild pulp inflammation, followed by slow dentin formation. Although polycarboxylate cement induced a very mild pulpal reaction, healing took place via the formation of thin irregular, poorly formed dentin bridges over a long period.

Acrylic Resins↗
PubMed1981

The rheological properties of polyelectrolyte cements. I. polycarboxylates.

The rheological behaviour of six setting carboxylate cements was studied by capillary techniques in the shear rate of 0.65-65 s-1 and the cements were found to behave as power law fluids. All cements became dilatant as setting progressed and the kinetics of apparent viscosity increase, were found to follow an exponential function of time, exp (mt), with m congruent to 0.5.

Acrylic Resins↗
PubMed1981

The rheological properties of polyelectrolyte cements II. Glass ionomers.

The rheological properties of two glass ionomer cements, ASPA and Fuji have been investigated. The viscosities of the liquid components of these systems have been found to be Newtonian up to a shear rate of 140 s-1 with values of 0.80 N m-2 s for ASPA and 1.8 N m-2 for Fuji. Capillary viscometry techniques have been employed to study the rheological changes accompanying setting. Both cements appear to behave as power law fluids, becoming progressively dilatant as setting proceeds. The apparent viscosities of the two systems are approximately equivalent displaying values of the order of 50 N m-2 s, at a shear rate of unity shortly after mixing.

Chemical Phenomena↗
PubMed1980

Capillary rheology of two composite resin systems.

The rheological properties of two commercial resin systems, Isopast and Cosmic, were studied in the shear rate range 0.65-65 s-1 by capillary techniques. Isopast represents a low inorganic filled composite, whereas Cosmic is a conventionally filled system whose resin matrix resembles that of Isopast. All components of both systems obeyed power law dependence of shear stress as a function of shear rate according to the relation 1n tau = 1n K + n 1n gamma; values of n for Cosmic catalyst and paste and Isopast paste were of the order of 0.6 whereas Isopast catalyst was of the order of 0.3. Setting systems obeyed a power law relationship during the working time with an exponent n congruent to 0.7-1.0. Accordingly the systems appear pseudoplastic in component form and slightly pseudoplastic to near Newtonian after mixing.

Chemical Phenomena↗
PubMed1980

Adhesion of periodontal dressings to enamel in vitro.

Adhesion to enamel is an important aspect of periodontal dressing retention. Details of tensile and shear bond strengths are presented for three dressing materials and a positive polycarboxylate control, and the data are discussed with regard to optimum levels of retention. A level of 2 MN/m2 is suggested for shear bond strength, and 1 MN/m2 for tensile bond strength, under the test conditions employed.

Acrylates↗