Лако-красочные материалы — производство

The shortcomings of the unfilled acrylic resins as luting agents were emphasized in Section II. B.7, and for similar reasons, these clear acrylics have failed to establish themselves as restorative materials. The composite resins on the other hand, after a lengthy development period have come to be recognized as one of the most useful and […]

Although prevalently used as luting and cavity-lining cements, the glass ionomers play a moderate part as cavity-filling materials, largely on the strength of their adhesion to the enamel and dentin of the tooth structure, the polyacid components participating in ionic bond formation with calcium cations of the hydroxyapatite in addition to undergoing weak ionic and/or […]

In addition to certain biological requirements, such as cariostatic properties and lack of pulp irritability or systemic toxicity, a filling material should possess low water absorption and should not dissolve in the oral fluids. The dimensional changes (generally involving contraction) on hardening of the material should be minimal so as to preclude tensile and/or shear […]

While dental amalgam is still the most widely used cavity filling material for the direct restoration of defects in posterior teeth, the retention of amalgam filling is due entirely to macromechanical containment in the undercut cavity. The same holds true for the silicate filling materials, which have for many decades been used for anterior restoration. […]

Although originally used as direct filling materials, the glass ionomer (GI) cements have since proven their worth in a number of different dental applications, including the pre­viously discussed luting of restorations. Their use as cavity base and lining materials has increased rapidly in recent years, and in this area the glass ionomers have established themselves […]

Once again, one is dealing here with a class of materials described in Section II. B.5 as luting agents, and indeed the only major difference compared to luting agents is that of consistency, the polycarboxylates used as cavity base or lining materials having a higher viscosity as a consequence of a higher concentration of the […]

The compositional and performance features of the zinc oxide-eugenol and zinc oxide- ortho-ethoxybenzoic acid cements were dealt with in Sections II. B.3 and II. B.4. While employed for temporary luting and filling, the ZOE materials find their major use in cavity lining. The fundamentally weak cement materials are usually reinforced for this purpose with poly(methyl […]

The zinc phosphate materials, discussed in Section II. B.1 as luting agents, are also in use for cavity lining. The major difference, compared to the luting cements, is the more putty­like consistency required for base or lining purposes and brought about by increasing the powder/liquid ratio to, maximally, 3.2g/mL. A cement of this composition sets […]

One of the oldest lining materials in use, calcium hydroxide cement still enjoys some popularity in this field, although in a vastly modified form. It has antibacterial properties, is biocompatible, and promotes pulp recovery and regrowth of dentin. In the original form used—namely, as a suspension of calcium hydroxide in water—it yielded cements too weak […]

In the process of hardening, the overlying filling material may exert considerable pressure on the liner. Additional forces, mostly compressive in nature, will be transmitted to the liner through the hardened restorative as the completed restoration is subjected to the stresses of mastication. To prevent liner deformation and flow under the packing load in the […]