A new method for assessment of marginal sealability of dental restorations.

A new testing system was developed for assessment of marginal sealability of dental restorations. It was constructed with a thermocycle loading line and a leakage detecting line partitioned from each other by the restoration under evaluation. The hot and cold solutions of rhodamine B as a tracer were alternately circulated in the thermocycle loading line by the switching of six solenoid valves.

Adsorption of 2-hydroxyethyl methacrylate on dentin from aqueous solution.

The adsorption of 2-hydroxyethyl methacrylate (HEMA) on bovine dentin from aqueous solution was examined to clarify the priming effects of HEMA on dentin bonding. HEMA adsorption was characterized by: (1) slow attainment of equilibrium at higher concentrations (after 72 h); (2) a linear isotherm with a maximum possible adsorption, where an abrupt horizontal plateau occurred; (3) the large adsorption of ca. 2.

[The surface degradation of various light-cured composite resins by thermal cycling].

The durability of four commercially available light-cured composite resins was investigated by thermal cycling, GR containing inorganic fillers treated with the graft polymerization of acryl ester, LF inorganic fillers treated with a silane coupling agent, PC silanized inorganic fillers and organic composite fillers, and the MFR-type SI containing the organic composite fillers. These materials were given 10,000, 30,000 and 50,000 thermal cycles (4 degrees C-60 degrees C) and the deterioration of materials by thermal cycling was evaluated by the measurement of the mechanical properties and the SEM observations of the surface of the thermocycled materials. Compressive strength and bending elastic moduli for all materials did not change greatly by thermal cycling.

[Effects of tooth surface treatment with the acid solutions containing metal chloride on the bond strength of a self-curing resin].

We evaluated the use of aqueous solutions containing an acid and metal chloride as a tooth surface pretreating agent. Nineteen solutions containing 10% acetic (AA), citric (CA), lactic (LA) or phosphoric acid (PA) and/or 0.11 M aluminum (Al), cupric (Cu) or ferric chloride (Fe) were prepared.

[Effects of monomer compositions on the bond strength of experimental light-cured 3-MBA resins to tooth substrates].

An adhesion promoting monomer of 3-methacryloyloxybenzoic acid (3-MBA) was utilized as an ingredient of experimental dental photocurable bonding resins. Effects of the monomer compositions of the resins on the bond strength to tooth substrates were examined. The bond strength of the light-cured resin was enhanced by the addition of 3-MBA.