Epidemiological investigation of caries prevalence in first grade school children in Rhineland-Palatinate, Germany.

INTRODUCTION: The annual examination of first graders' oral health as stipulated by law aimed to reach every child in Rhineland-Palatinate (Germany) in their first year of school. We intended to evaluate the first graders' oral health based on the examination data for 2013/2014. METHODS: Instructed examiners measured the d3mft(deciduous)/D3MFT(permanent) index according to World Health Organization criteria in 25,020 predominantly 6-7 year-old first-grade school children. Only caries affecting dentin was diagnosed; no radiography or fiber-transillumination was used. Out of the d3mft value, the "Significant Caries Index" (SiC) was calculated. This index identifies the dmft score of the third of the population with the highest caries experience. Descriptive analysis was performed. RESULTS: Out of the the examined children, 60.9% were caries free. Mean d3mft score was 1.28 ± 2.27 while the mean SiC was 3.73 ± 2.51. A distinctly higher d3mft was found in the decidous molars compared to the front teeth. Boys were significantly more caries-experienced than girls (p < 0.001). CONCLUSION: The results of this study confirm the lasting trend towards decreasing caries prevalence in children starting school found in previous cross-sectional studies. This trend was observed in the high-risk group (obtained by SiC) as well as in the entire study population. Particular attention in caries prophylaxis should be paid to the primary molars.

Cell cycle association and hypoxia regulation of excision repair cross complementation group 1 protein (ERCC1) in tumor cells of head and neck cancer.

Excision repair cross complementation group 1 (ERCC1) is a key component of homologous recombination-based repair of interstrand DNA cross-links (ICLs). As a consequence, ERCC1 mediates resistance to mitomycin C (MMC) and platinum chemotherapeutic agents and may predict treatment failure. Clinical response to MMC or cisplatin (CDDP)-based radiochemotherapy (RCT) was assessed in 106 head and neck squamous cell carcinoma (HNSCC) patients and correlated with cell nuclear immunoreactivity of the mouse monoclonal (clone: 8 F1) ERCC1 antibody in tumor tissue samples. BEAS-2B epithelial and Detroit 562 pharyngeal squamous carcinoma cells were treated with CDDP, MMC, and 5-fluorouracil (5-FU) at 50 % growth inhibitory (IC-50) concentrations. ERCC1 protein synthesis was compared with cell cycle distribution using combined immunocytochemistry and flow cytometry. ERCC1 messenger RNA (mRNA) and protein expression was investigated in normoxic and hypoxic conditions in Detroit 562 cells. Clinically, the nonresponder revealed significantly lower HNSCC tissue ERCC1 immunoreactivity than the responder (p = 0.0064) or control normal mucosa, which led to further mechanistic investigations. In vitro, control cells and cells treated with cytotoxic agents showed increasing ERCC1 levels from the G1 through S and G2 phases of the cell cycle. In CDDP-treated cells, ERCC1 mRNA and protein expression increased. Under hypoxic conditions, ERCC1 gene expression significantly decreased. Although ERCC1(+) cells show increased chemoresistance, they might be particularly radiosensitive, representing G2 cell cycle phase and less hypoxic. ERCC1 expression might be indirectly related with some conditions important for RCT treatment, but it is not a clear predictor for its failure in HNSCC patients.