Purpose: To verify the effects of five candidates for oral probiotics on Haemophilus influenzae and to more characterize the effects of Lactobacillus crispatus YIT 12319 (L.c1).

Materials and Methods: Cell free culture supernatants (CFCSs) were acquired from cultures of the clinical isolates (oral probiotic candidate bacteria). Two laboratory strains of H. influenzae (type b and non-typeable) were freshly cultured in Muller-Hinton broth medium. A paired competition assay was performed using each clinical isolate versus one of the two H. influenzae strains on culture plates. Antibacterial effects of all unprocessed CFCSs, neutralized CFCSs, and an ammonium sulfate precipitate of the CFCSs against H. influenzae were determined using a radial diffusion assay. The bactericidal effect of L.c1 CFCS was also verified using a colony formation assay. Furthermore, the organic acids produced by L.c1 were analyzed using HPLC.

Results: L.c1 displayed uninterrupted growth by suppressing the growth of both stains of H. influenzae equally, while the results for the rest of the clinical isolates were inconsistent. Only unprocessed CFCS of L.c1 clearly inhibited the growth of H. influenzae strains and showed potentially strong bactericidal effects. Reasonable amounts of lactic acid, acetic acid, succinic acid, and propionic acid were detected by HPLC.

Conclusion: The effects of L.c1 on H. influenzae strains observed in this study will serve as important supporting evidence for the potential use of lactobacillus species as probiotics. In addition, the growth appeared to be inhibited by the organic acids produced by L.c1.

Purpose: The aim of this study was to observe marginal sealing and resin composite adaptation to cavity walls using the dye penetration test and environmental scanning electron microscope.

Materials and Methods: Cylindrical cavities were prepared on cervical regions of teeth. Teeth were restored with Clearfil Liner Bond 2V adhesive and filled with Clearfil Photo Bright or Palfique Estelite resin composites. These resin composites were cured with a conventional light-curing method. After thermal cycling, the specimens were subjected to the dye penetration test to evaluate marginal sealing and resin composites adaptation to the cavity walls. These resin-tooth interfaces were then observed using environmental scanning electron microscope.

Results: Enamel crack formation was observed in all specimens. Gap formation between the resin composite and cavity walls was observed for both resin composites.

Conclusion: Environmental scanning electron microscope showed high enamel crack formation for both resin composites after light curing. Enamel cracks were located at 25-100 μm from the resin-enamel interface on environmental scanning electron microscope observations. Enamel cracks were observed in the enamel surface to the dentin-enamel junction. Environmental scanning electron microscope showed cavity wall gap formation in the dentin-adhesive interface or resin-adhesive interface.

Indirect composite material and metallic framework are chemo-mechanically bonded with adhesive systems. This technical report describes a fundamental bonding technique for silver-palladium-copper-gold alloy. The procedure reported here is applicable in fabrication of both single restorations and fixed dental prostheses.