Purpose: The purpose of the present study was to investigate the bond strength of an indirect composite material to a magnetic stainless steel alloy.

Materials and Methods: The surfaces of machined magnetic stainless steel alloy specimens were abraded with 600-grit silicon carbide paper and then grouped according to the type of surface treatment given: 1) without preparation, 2) tribochemical silica coating, 3) air abrasion with 50 µm alumina, 4) tribochemical silica coating and application of opaque resin, 5) air abrasion and application of a metal conditioner for base metal alloys, and 6) air abrasion, application of a metal conditioner and opaque resin. An indirect composite material (Estenia C&B) was then applied to the treated surfaces of the alloy and polymerized. The specimens in groups 2-6 were thermocycled up to 10,000 cycles. The specimens in groups 5 and 6 were thermocycled up to 20,000 cycles. The shear bond strengths were determined using a universal testing machine.

Results: All of the cylindrical columns of the indirect composite material in group 1 debonded before their shear bond strengths could be determined. Group 6 exhibited the greatest bond strength, followed by group 5, compared to the other groups before thermocycling (p<0.05). The bond strengths of groups 3-6 did not decrease after thermocycling (p>0.05), whereas those of group 2 significantly decreased (p<0.05).

Conclusion: Significant improvement in the bond durability of an indirect composite material to a magnetic stainless steel alloy was achieved by alumina air abrasion and the application of a metal conditioner for base metal alloys and opaque resin, followed by pre-polymerization.

This article describes the chairside and laboratory procedures utilized to create the functionally compatible border region of a complete denture with good retention and that causes no pain using a dynamic impression material and autopolymerizing pour-type denture base resin.

Purpose: To develop a new selective culture medium specifically for Streptococcus anginosus.

Materials and Methods: Three antibiotics, sulphamethazine (s), aztreonam (a), and bacitracin (b), were tested by adding to Tryptic Soy (TS) agar at different concentrations. Initially, sulphamethazine (1.0 mg/mL) and aztreonam (0.2 mg/mL) were added to TS agar to obtain TS-sa agar. In total, 24 strains of oral bacteria including three clinical S. anginosus isolates were used during the entire study. A minimal inhibitory concentration (MIC) test was performed by using 96-well plate to determine the optimal bacitracin concentration for the selective medium for S. anginosus under anaerobic condition at 37ºC for 48 hours. Finally, bacitracin was added at a concentration of 2.0 U/mL to TS-sa agar to prepare TS-sab agar medium and selectivity was tested using all 24 strains of bacteria.

Results: Most strains of S. anginosus could grow on the TS-sab agar medium but other bacteria except for S. intermedius and S. sobrinus could not be detected on this medium. S. intermedius and S. sobrinus occasionally showed some growth on TS-sab agar medium with low detection rate. Although some clinical isolates of S. anginosus were not enriched like other strains of S. anginosus, a remarkable enhancement was achieved in this study in the development of a selective culture medium for S. anginosus.

Conclusion: TS-sab may serve as a remarkably improved semi-selective culture medium for S. anginosus. Continued studies are required to improve the selectivity specific for S. anginosus.

This article describes the clinical course of a repaired resin-bonded fixed partial denture (RB-FPD). A posterior FPD cast from silver-palladium-copper-gold alloy (Castwell M.C. 12) was applied to a 27-year-old male patient. A three unit FPD with wrap-around retainers was fabricated. After try-in, the framework surface to be bonded was air-abraded with alumina. The FPD was then treated with a single liquid priming agent (V-Primer), and bonded with a tri-n-butylborane (TBB) initiated adhesive resin (Super Bond Opaque). Sixteen years after seating, fracture of the molar abutment occurred at the bucco-distal cusp and distal marginal ridge around and under the retainer. The fractured area was reduced with a diamond rotary cutting instrument and an inlay cavity was prepared. The cavity preparation was restored with the same system as the RB-FPD. After an observation period of 23 years and six months, the original FPD was functioning satisfactorily. The materials and bonding technique reported here are applicable as an option for a minimally invasive fixed prosthodontic treatment.