Cytotoxicity of a trial resin composite liner containing TiK2F6 on rat dental pulp cells

The aim of this study was to assess the toxicological responses of a resin composite containing TiK2F6 and NaF in rat dental pulp cells. Trial resin composite liners were made, containing 3 wt% fluorides (TiK2F6 or NaF). These specimens were immersed in 5 ml of cell culture medium supplemented at 37 degrees C for 24 hours. The eluates were used for the experiments. We judged the cytotoxicity of the samples by the cell viability. The original elute solution was serially diluted and then the medium was exchanged for the dilute medium. The cell viability at 1, 2 or 5 days after commencement of re-culturing was calculated. The viability of cells in the eluate from the resin composite liners containing TiK2F6 and NaF decreased with time. The cytotoxicity of TiK2F6 was weaker than that of NaF at all times.     

Clinical pathology study of lingual carcinoma treatment with CDDP-AMS microcapsules through lingual artery]

11 patients with lingual carcinoma were treated by artery chemoembolization with 100 mg CDDP-AMS microcapsules (CDDP 13.6 mg) through lingual artery, and the average diameter of microcapsules was 56.3 microns. There was no obvious carcinoma cell or carcinoma tissue in pathologic specimens of the tissue after 4 weeks of treatment. After 5-6 weeks of chemoembolization, the clinical tumor ulcer disappeared, but it was difficult to judge the change of the tumor because of local fiber tissue. After 6 months, by observation of 4 patients whose tumors had not been excised, it was found that the infiltuation mass of primary carcinoma disappeared and tongue body became soft. It suggests that artery chemoembolization with CDDP-AMS microcapsules is an efficient way of lingual carcinoma treatment.     

Gingival fibroblast response to cyclosporin A and transforming growth factor β1

This study investigates a potential role for TGFβ₁ in the pathogenesis of cyclosporin A-induced gingival overgrowth (CsA-OG). TGFβ₁ was localized immunohistochemically in the connective tissue of both normal gingiva and CsA-OG. Intense staining for TGFβ₁ was detected at the tips of the dermal papillae of the overgrown gingiva. In addition, fibroblasts derived from healthy gingiva and fibroblasts derived from CsA-OG were cultured both as monolayers or embedded in a 3D-collagen gel. Fibroblast activity was monitored in terms of protein and collagen production in the presence of (i) 1 ng/ml TGFβ₁ (ii) 500 ng/ml CsA, or (iii) 500 ng/ml CsA and 1 ng/ml TGFβ₁. In monolayer culture TGFβ₁ significantly increased protein and collagen production in all cell strains (p<0.05); however, there was no difference in response between fibroblasts from overgrown and healthy tissue. The production of both protein and collagen was significantly lower in the presence of the combination of CsA and TGFβ₁ when compared with the maximal stimulation produced by TGFβ₁ alone. In gel, TGFβ₁ significantly elevated matrix production by all overgrown cell strains (p<0.05) but had little or no effect on the normal cell strains. The combination of CsA and TGFβ₁ in gel cultures reduced protein and collagen production by overgrown cell strains compared with TGFβ¹ alone. It is concluded that the cellular activity of gingival fibroblasts is dependant on culture conditions and that fibroblasts derived from overgrown gingival tissue are more responsive to TGFβ₁ than normal gingival fibroblasts when cultured in type I collagen gel.     

Allergic skin reactions provoked by a root canal disinfectant with reduced formaldehyde concentration

Abstract. The immunogenic potential of a root canal disinfectant (FA 6/25) with a reduced formaldehyde concentration (one-third of that in Formocresol) was studied after application to one incisor tooth per guinea-pig, both presensitized and non-presensitized. Skin reaction after occlusive patch testing was studied. Several indications were found that the disinfectant caused an allergic reaction.     

Daily variations in occlusal contacts

In this study the location and severity of occlusal contacts in the morning and evening on 3 separate days were recorded for 10 women. Biofeedback therapy was used after evening recordings to encourage muscle relaxation. The findings suggest that occlusion and occlusal contacts change throughout the day and depend on the physical state of the masticatory muscles and the mental state of the patient. Although this conclusion is understandable, its effects on the philosophies of occlusal rehabilitation are questionable. Further studies are needed to evaluate the significance of the contact variations in occlusal restorations placed at different times.     

Odontoblast metabolism in rats deficient in vitamin D and calcium. II. Changes in activities of alkaline phosphatases.

Rats were fed a low calcium diet deficient in vitamin D for 14 days. Changes in alkaline phosphatase activities in odontoblasts dissected out from incisor teeth were studied biochemically. A strong increase in pNPP-ase, PPi-ase, total ATP-degradation and Ca2+- ATPase was observed in the deficient animals compared with animals fed a control diet.     

Activation of the complement system by some gram-positive oral bacteria.

Actinomyces viscosus 19246, T₁₄V and T₁₄AV, Streptococcus mutans and Streptococcus sanguis consumed complement in vitro. Complement (C) profile analysis revealed that C₄ and C_3–9 were consumed concomitantly in unadsorbed human serum. In serum from which naturally occurring agglutinating antibodies had been removed, the same microorganisms caused C_3–9 consumption in the absence of a demonstrable loss of C₄ activity. Congenitally C₄-deficient guinea-pig serum (C₄D) supported a similar consumption of C_3–9. The Gram-positive plaque microorganisms tested activated serum complement by the classical as well as the alternate pathways. Dental plaque microorganisms may cause a similar activation of gingival crevicular fluid complement in vivo, thus resulting in complement-mediated inflammatory processes.