Influence of novel resin monomer on viability of L-929 mouse fibroblasts in vitro.

We have previously synthesized a novel acrylic resin monomer, methacryloyloxyethyl methyl succinate (TA). The aim of this in vitro study, therefore, was to examine its influence on cell viability using L-929 mouse fibroblasts and then compare the results with MMA, EMA, and LMA. Medium containing each monomer was changed every 15 minutes as some monomers were volatile. After one hour of exposure, these mediums were replaced with a normal medium and cells were further incubated for 72 hours. IC50 value for each monomer was determined, and chronological cell viability and cytomorphologic observation were evaluated. Viability was impaired in a dose-dependent manner. All monomers, except TA, tended to correlate between molecular weight and cell viability. On the other hand, TA showed excellent viability and did not impair growth abruptly. These results thus demonstrated that cellular damage by TA was much lower than that by other monomers.

Effects of scaling and root planing on the amounts of interleukin-1 and interleukin-1 receptor antagonist and the mRNA expression of interleukin-1beta in gingival crevicular fluid and gingival tissues.

OBJECTIVE: The purpose of this study was to evaluate the relationship between the clinical changes after non-surgical periodontal therapy and interleukin 1 (IL-1) in gingival crevicular fluid (GCF) and gingival tissues from patients with chronic periodontitis. BACKGROUND: The inflammatory responses mediated by IL-1 play an important role in periodontal tissue destruction. Although numerous studies have attempted to elucidate the dynamic movement involved in chronic periodontitis, the results have often conflicted. Such discrepancies may have been due to the inability to determine clinical disease activity. METHODS: Seven patients with chronic periodontitis were examined. The severity of periodontal inflammation was expressed using clinical parameters before and after a scaling and root planing (SRP) procedure. The amounts and concentrations of IL-1alpha, IL-1beta and IL-1 receptor antagonist in GCF were measured by enzyme-linked immunosorbent assay (ELISA) and IL-1 activity index was calculated. A needle biopsy in matching gingival tissues was also performed before and after the SRP procedure. The localization and mRNA expression of IL-1beta were determined using histological methods. RESULTS: Clinical parameters improved slightly after the SRP procedure. Only the probing pocket depth (PPD) was reduced significantly (p < 0.05). However, the amount of IL-1beta in GCF was slightly increased. The localization and mRNA expression of IL-1beta could still be observed after the SRP procedure. Therefore, none of the clinical parameters showed a high sensitivity or specificity for evaluating subgingival inflammation. CONCLUSION: These observations suggest that IL-1 is effective for evaluating in detail the state of subgingival inflammation.