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INTRODUCTION: The aim of the present study was to determine the antimicrobial effect of various gel formulations on plaque formation; different tooth gels were compared to a toothpaste containing comparable antimicrobial ingredients with regard to its microbiocidal activity. The study was conducted under the assumption, that a chief requirement for the prevention of plaque formation is the combination of mechanical removal and antimicrobial activity, and not the sole capability of mechanical plaque removal. METHODS: Ledermix(®) fluoride gel as commercially available with preservative, and without preservative and perfume oils, Elmex(®) gelée, and Meridol(®) toothpaste were tested in a standardized in-vitro test modification of the quantitative suspension test EN 1040. Instead of testing in a suspension, the respective product was directly placed on a standardized contaminated sterile stainless steel disk without adding any bio-burden. 50% egg yolk in Aqua dest. was used as a neutralizer. RESULTS: Within 1 min, Elmex(®) gelée showed a RF >5 log(10) against S. pyogenes and S. sanguinis. Against S. mutans, a log(10) RF of ≥5 was achieved after 2 min, against C. albicans after 5 min, and against P. aeruginosa after 10 min S. aureus was the most difficult organisms to be reduced. After an application time of 10 min, only a log(10) RF of 2.4 was achieved. Ledermix exceeded the antimicrobial efficacy of Elmex(®) gelée against S. mutans and C. albicans and was already effective against these organisms after 1 min, but did not show the same antimicrobial efficacy as Elmex(®) gelée against P. aeruginosa. Similar to Elmex(®) gelée, a required reduction of >5 log(10) for antimicrobials under no organic challenge was not achieved against S. aureus. Ledermix(®) fluoride gel without preservatives and Ledermix(®) fluoride gel without preservatives and perfume oil did not show the antimicrobial efficacy of the standard Ledermix(®) fluoride gel formulation, indicating that the observed antimicrobial efficacy is chiefly based on the preservative, and possibly the perfume oil. Compared to the tested gels, Meridol(®) toothpaste was less effective and reached any antimicrobial effect >5 log(10) only against S. sanguinis after 10 min. CONCLUSION: All unmodified tested gels showed an antimicrobial effect. Because no relevant antimicrobial efficacy against plaque forming bacteria was achieved within 2 min, in practice, an anti-plaque forming effect based on the antimicrobial action of gels cannot be assumed when used in the oral cavity. However, the results of the present study indicate that the antimicrobial efficacy of gels is determined by their formulation and that for the prevention of plaque formation the combination of mechanical removal and antimicrobial activity is not the chief requirement only, but a sustained antimicrobial effect may be of greater importance.
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OBJECTIVE: To determine if micrometastatic disease in the sentinel lymph node is a predictor of non-sentinel lymph node (non-SLN) involvement in breast cancer. SUMMARY BACKGROUND DATA: Sentinel lymph node biopsy (SLN) is an accepted alternative to axillary dissection in staging breast cancer. If the SLN contains metastatic foci, the standard recommendation is completion axillary node dissection (CAD). However, a large subset of patients with metastasis limited to the SLN is unnecessarily subjected to the morbidity of CAD. METHODS: A retrospective review of prospectively gathered breast cancer patients having SLN was conducted. Patients with metastasis to the SLN were selected for analysis. Various clinicopathologic features were analyzed for association with metastasis to the non-SLN. RESULTS: A total of 194 women underwent successful SLN dissection. Metastasis to the SLN was found in 48 patients (21 had micrometastases, 27 had macrometastases). Of those with micrometastases, 16 underwent CAD with 1 patient having metastasis to the non-SLN. In patients with macrometastases, 26 had CAD with 14 patients having non-SLN metastasis. Multivariable logistic regression identified only macrometastatic disease in the SLN as significantly associated with involvement of the non-SLN (P = 0.03). None of the patients with micrometastases, including those without CAD, has evidence of local recurrence to date (3-30 months). CONCLUSION: This study demonstrates that the incidence of non-SLN involvement is low in SLN that contains only micrometastatic foci and is within the accepted range of the false-negative rate of SLN. This suggests that a CAD may be omitted in patients with micrometastatic disease.