Evaluating IL-2 levels in human pulp tissue.

In murine and human CD4+ T cell populations, there are three subpopulations of T helper cell types. Hahn et al. demonstrated the ratio of CD4/ CD8 + cells significantly increases in inflamed dental pulps compared with normal pulps. Elevated levels of interleukin (IL)-2 have been detected in inflamed dental pulps and the level of IL-2 could be used as a marker for inflammation. In this study, levels of IL-2 were evaluated by using a human IL-2 cytokine assay kit on 80 samples of freshly extracted human pulp tissue. Applying standard diagnostic procedures, the tissue samples were clinically categorized into one of three experimental groups. The results demonstrated that there were no significant differences between the concentrations of IL-2 in any of the experimental groups. Our findings are different from results reported previously. Further investigation is warranted to determine if a correlation exists between the concentration of IL-2 or other interleukins and the degree of inflammation present in the dental pulp.

Generation of site-appropriate tissue by a living cellular sheet in the treatment of mucogingival defects.

BACKGROUND: Generation of site-appropriate tissue in the oral cavity includes the restoration of the correct anatomic type, amount, and distribution of the tissue. This study is a post hoc analysis of data collected during previously published results from two randomized clinical trials of a living cellular sheet (LCS; allogenic cultured keratinocytes and fibroblasts in bovine collagen) versus a free gingival graft (FGG), evaluating their ability to augment keratinized tissue or gingiva. METHODS: Post hoc histologic and clinical (photographic) comparisons of the outcomes of treatment were performed on histologic and photographic data gathered in the two randomized clinical trials. RESULTS: Histologic findings showed that LCS-treated sites resembled gingiva rather than alveolar mucosa. Photographic analysis indicated that LCS treatment resulted in more site-appropriate tissue than FGG in terms of tissue color, with adjacent untreated tissue, absence of scar formation or keloid-like appearance, and mucogingival junction alignment. CONCLUSION: Treatment of mucogingival defects with LCS resulted in the generation of tissue that is more site appropriate than tissue transplanted from the palate.

Microbial diversity of biofilms in dental unit water systems.

We investigated the microbial diversity of biofilms found in dental unit water systems (DUWS) by three methods. The first was microscopic examination by scanning electron microscopy (SEM), acridine orange staining, and fluorescent in situ hybridization (FISH). Most bacteria present in the biofilm were viable. FISH detected the beta and gamma, but not the alpha, subclasses of Proteobacteria: In the second method, 55 cultivated biofilm isolates were identified with the Biolog system, fatty acid analysis, and 16S ribosomal DNA (rDNA) sequencing. Only 16S identified all 55 isolates, which represented 13 genera. The most common organisms, as shown by analyses of 16S rDNA, belonged to the genera Afipia (28%) and Sphingomonas (16%). The third method was a culture-independent direct amplification and sequencing of 165 subclones from community biofilm 16S rDNA. This method revealed 40 genera: the most common ones included Leptospira (20%), Sphingomonas (14%), Bacillus (7%), Escherichia (6%), Geobacter (5%), and Pseudomonas (5%). Some of these organisms may be opportunistic pathogens. Our results have demonstrated that a biofilm in a health care setting may harbor a vast diversity of organisms. The results also reflect the limitations of culture-based techniques to detect and identify bacteria. Although this is the greatest diversity reported in DUWS biofilms, other genera may have been missed. Using a technique based on jackknife subsampling, we projected that a 25-fold increase in the number of subclones sequenced would approximately double the number of genera observed, reflecting the richness and high diversity of microbial communities in these biofilms.