Antimicrobial action of natural substances on oral bacteria

The antimicrobial action of natural substances was investigated in vitro against oral bacteria including Streptococcus sp., Actinomyces sp., Actinobacillus sp., Bacteroides sp., Capnocytophaga sp., Eikenella sp., Fusobacterium sp. and Propionibacterium sp. Among the natural substances tested, hinokitiol was the most inhibitory to oral bacteria. Cinnamon bark oil, papua-mace extracts, and clove bud oil in spice extracts were also inhibitory against many oral bacteria. Egg white lysozyme exhibited antimicrobial action against the periodontitis associated bacteria.     

Chondrosarcoma of the mandible. Report of case and a survey of 23 cases in the Japanese literature

A huge chondrosarcoma of the mandible (80 X 95 X 100 mm in size) with extension into the infratemporal fossa is described. The tumour was successfully treated by surgical removal and postoperative irradiation. A survey of the Japanese literature revealed 23 cases of chondrosarcoma with involvement of the mandible. The tumours occurred equally in males and females whose mean age was 38 years. The molar region was the site of predilection. The most common symptom was swelling and it was accompanied by pain in 7 cases and paraesthesia in 5 cases. Radiographically, the lesions were quite variable and with the exception of 3 cases in which information was not available, they consisted of a combination of irregular radiopacity and radiolucency in 9 cases, whereas the predominant feature was radiopacity in 6 cases and radiolucency in 4 cases. There was no radiographical abnormality in 2 cases. Root resorption of adjacent teeth was noted in 3 of 6 cases where information existed. Computed tomography was thought to be quite valuable in determining the nature and extent of the tumour. Although an elevation of serum alkaline phosphatase was observed in our case, results of laboratory tests were mostly of no diagnostic significance. Surgical removal was employed in 22 cases alone or in conjunction with irradiation and/or chemotherapy. Of 14 cases on whom information was available, local recurrence occurred in 6 cases in which radiotherapy was not given and distant metastasis in 2 of 10 cases on whom information was available. Of 20 patients on whom information was available on the postoperative course, 7 patients died 5 months to 6 years after the primary treatment.     

Molecular basis of salivary proline-rich protein and peptide synthesis: cell-free translations and processing of human and macaque statherin mRNAs and partial amino acid sequence of their signal peptides

Acidic proline-rich phosphoproteins and phosphopeptides are abundant components of parotid and submandibular salivary secretions in man and in the subhuman primate, Macaca fascicularis. The major acidic proline-rich proteins and the proline-rich phosphopeptide, statherin, of man and macaques have been shown to be potent inhibitors of calcium phosphate precipitation and are thought to function in the oral environment by maintaining saliva supersaturated with respect to calcium phosphate salts. Little is known about the biosynthesis of these proline-rich phosphoproteins and peptides, and the aim of the present work was to determine the structural relationship between statherin precursors and native human and macaque statherin. RNA was isolated from human submandibular gland, and poly(A+) mRNA was selected by affinity chromatography on oligo(dT) cellulose and translated in a reticulocyte lysate. Electrophoretic analysis of the translation products revealed that this mRNA directed the synthesis of a large number of polypeptides with Mrs ranging from 5000 to 70,000. Immunoprecipitates, prepared with an antiserum directed against human statherin, contained a single component with a Mr of 7800, approximately 2000 daltons larger than native statherin. Radiosequencing of the in vitro precursor of statherin in immunoprecipitates demonstrated the presence of a 19-residue signal peptide. These results suggest that statherin is derived from a unique structural gene, and does not result from proteolytic processing of a large polyprotein precursor.     

Colonization of the human oral cavity by a strain of Streptococcus mutans

Streptococcus mutans strain JH1001 produces a bacteriocin that can kill virtually all other strains of this micro-organism. The ability of JH1001 to colonize the human oral cavity was tested in a study involving five subjects and three different infection regimens, all of which involved multiple exposures to large numbers of organisms. Two and one-half years after infection, JH1001 was found to have persistently colonized three of the subjects. The indigenous S. mutans in one subject were reduced below the level of detection. Levels of (total) S. mutans and S. sanguis were not affected in persistently colonized subjects. Mutants of indigenous S. mutans resistant to the bacteriocin were not observed. The results indicate the importance of host variability and infection regimen for superinfection by this strain of S. mutans. The efficient replacement of indigenous S. mutans by JH1001 in one subject lends support to the eventual application of replacement therapy to the prevention of dental caries.     

Cytotoxicity of Epiphany and Resilon with a root model

AIM: To record the cytotoxicity of Resilon and Epiphany (Pentron clinical technologies, Wallingford, CT, USA) using a root model. METHODOLOGY: Thirty teeth with single roots were sectioned at the enamel-cementum junction, the root canals prepared and each root then sterilized before filling with the lateral condensation technique using one of three filling materials (n = 10 per group): Resilon and Epiphany, Sealite (Septodont, Pierre Rolland, Merignac, France) and gutta-percha, Roekoseal Automix (Coltène/Whaledent, Langenau, Germany) and gutta-percha. The roots were stored at 37 degrees C in an incubator to allow for setting of the root filling materials. The apices of the roots were dipped in 1 mL of MEM culture medium for 1, 2, 7 and 30 days renewing the medium every day. After 24 h contact between the medium and the filled roots, the medium was used to measure the cytotoxicity on mouse fibroblasts L 929 with the MTT assay that recorded the mitochondrial activity of the target cells. An additional test according to ISO 10993-5 standards was undertaken to compare Resilon and Epiphany. RESULTS: The root model showed no statistically significant differences between the sealers at 7 and 30 days (NS). Epiphany and Resilon were the most cytotoxic materials at 1 and 2 days (P < 0.001). Unlike Epiphany, Resilon was not cytotoxic when tested according to ISO 10993-5 standards. CONCLUSIONS: The cytotoxicity of Resilon + Epiphany, due mainly to Epiphany, decreased after 2 days to reach a level comparable with commonly used root canal sealers.