Genetic diversity of gamma-hexachlorocyclohexane-degrading sphingomonads isolated from a single experimental field

Aim:  To determine the effect of the surface roughness of denture acrylic on the attachment of Streptococcus oralis .
Methods and Results:  Roughened denture acrylic samples were assessed for bacterial attachment, over time, using microscopy. The area of the image covered by bacteria was calculated and converted into a percentage of the total area sampled. The results showed an increasing bacterial coverage with time of incubation and increasing roughness. Differences were seen between heat cured acrylic and cold cured acrylic.
Conclusion:  This study successfully demonstrated a system for the assessment of the amount of attached bacteria on denture acrylic varying roughness. The system was able to discern the difference in surface area coverage by attached bacteria over a roughness range relevant to brushing dentures with dentifrices.
Significance and Impact of Study:  This study provides strong support for the scratches caused by brushing dentures with dentifrice encouraging bacterial attachment. This is likely to have a significant effect on efficacy of denture cleaning, general hygiene and biofilm re-formation between cleaning regimens and may indicate that alternative low abrasive cleaners, such as antimicrobial denture-cleaning tablets, offer a more appropriate regimen.     

HPLC法测定牙膏中柚皮苷的含量

建立了高效液相色谱测定牙膏中柚皮苷含量的方法。采用的色谱条件:Hypersil BDS C18色谱柱(250 mm×4.6 mm,5μm);柱温为40℃;以水(A相)和乙腈(B相),梯度洗脱程序为:0～15 min,10%～100%B;流速为1.0 mL/min;检测波长为283 nm;进样量为20μL。结果表明,柚皮苷的质量浓度在14.55～116.40μg/mL范围内与峰面积呈良好的线性关系(r=0.9999),平均加标回收率为97.56%。该方法稳定、准确,重现性好,可作为牙膏中柚皮苷的含量测定和质量控制方法。     

Effect of commercial herbal toothpastes and mouth rinses on the prevention of enamel demineralization using a microcosm biofilm model

Abstract

This work evaluated the effects of commercial toothpastes and mouth rinses containing natural/herbal agents on biofilm viability, extracellular polysaccharide (EPS) production and on enamel demineralization in vitro. Microcosm biofilm was produced on bovine enamel for 5?days and treated daily with: Orgânico natural^® (toothpaste/mouth rinse), Boni Natural Menta &; Malaleuca^® (toothpaste/mouth rinse), Propolis &; Myrrh^® (toothpaste), Colgate Total 12 Clean Mint^® (toothpaste, positive control), Malvatricin^® Plus (mouth rinse), PerioGard^® (mouth rinse, positive control) or PBS (negative control). Tom’s Propolis &; Myrrh^® and Colgate Total 12^® toothpastes and Malvatricin^® Plus and PerioGard^® mouth rinses significantly reduced biofilm viability (p?® had significant effects on biofilm thickness and EPS. Despite the indication that Tom’s Propolis &; Myrrh^® significantly reduced lesion depth, only Colgate Total 12^® significantly reduced mineral loss. Malvatricin^® Plus significantly reduced mineral loss and lesion depth, as did PerioGard^®. Some herbal products, Malvatricin^® Plus and Tom’s Propolis &; Myrrh^®, showed anticaries effects.     

In vitro antioxidant activities of antioxidant-enriched toothpastes

Several forms of periodontal diseases (PD) are often associated with modified phagocytosing leukocytes and contemporary free radical production. Host antioxidant defenses could benefit from toothpastes used as adjuncts to counteract plaque-associated bacteria. The aim of the present study was to determine possible antioxidant activity (AA) of 12 differently antioxidant-enriched toothpastes, regardless of their efficacy as antimicrobial agents. Toothpastes were enriched alternatively with sodium ascorbyl phosphate, α-tocopherol acetate, pycnogenol, allantoin and methyl salycilate or a mixture of these. AA was tested in a cell-free system with a ABTS-decolorization assay improved by means of a flow injection analysis device. Comet assay, using NCTC 2544 keratinocytes, was performed to test if it was possible to identify any protection against in vitro DNA fragmentation provoked by a challenge with H₂O₂ in cultures pre-incubated with toothpaste extracts.

Only toothpastes containing sodium ascorbyl phosphate displayed clear AA with I₅₀ values ranging between 50 and 80?mg of toothpaste/ml water. COMET analysis of cells challenged with H₂O₂ in presence of toothpaste extracts revealed a limited protection exerted by sodium ascorbyl phosphate. The results described herein indicate that toothpastes containing sodium ascorbyl phosphate possess AA. All the data were obtained in systems in vitro and the demonstration of in vivo AA is desirable. These findings could be useful in the treatment and maintenance of some forms of PD and should be considered when arranging new toothpaste formulations.     

Clinical reversal of root caries using ozone, double-blind, randomised, controlled 18-month trial

Objective : To assess the effect of an ozone delivery system, combined with the daily use of a remineralising patient kit, on the clinical severity of non‐cavitated leathery primary root carious lesions (PRCL's), in an older population group. Design : Atotal of 89 subjects, (age range 60–82, mean ± SD, 70.8 ± 6 years), each with two leathery PRCL's, were recruited. The two lesions in each subject were randomly assigned for treatment with ozone or air, in a double‐blind design, in a general dental practice. Subjects were recalled at three, six, 12 and 18 months. Lesions were clinically recorded at each visit as soft, leathery or hard, scored with a validated root caries severity index. Results : There were no observed adverse events. After three months, in the ozone‐treated group, 61 PRCL's (69%) had become hard and none had deteriorated, whilst in the control group, four PRCL's (4%) had become worse (p<0.01). At the six‐month recall, in the ozone group, seven PRCL's (8%) remained leathery, the remaining 82 (92%) PRCL's had become hard, whilst in the control group, 10 PRCL's had become worse (11%) and one had become hard (p<0.01). At 12 and 18 months, 87 Subjects attended. In the ozone group at 12 months, two PRCL's remained leathery, compared to 85 (98%) that had hardened, whilst in the control group 21 (24%) of the PRCL's had progressed from leathery to soft, i.e. became worse, 65 PRCL's (75%) were still leathery, and one remained hard (p<0.01). At 18 months, 87 (100%) of ozone‐treated PRCL's had arrested, whilst in the control group, 32 lesions (37%) of the PRCL's had worsened from leathery to soft (p<0.01), 54 (62%) PRCL's remained leathery and only one of the control PRCL's had reversed (p<0.01). Conclusions : Leathery non‐cavitated primary root caries can be arrested non‐operatively with ozone and remineralising products. This treatment regime is an effective alternative to conventional “drilling and filling”.     

中药白芨在牙膏中的应用研究

根据中药白芨具有抗菌消炎、敛疮止血的功能,通过水提醇沉提取及与丹皮酚制成包合物后,将其应用于牙膏中,性温、刺激小、安全无毒,可用于防治口腔溃疡、咽喉肿痛、牙周炎、牙龈炎、防龋、口腔异味等口腔和牙科疾病,符合回归自然、崇尚绿色的发展趋势。     

A comparison of four home-care fluoride programs on the caries incidence in the elderly

Objective : To estimate the caries preventive effect of 4 fluoride programs over 2 years in the elderly. Setting : The Public Dental Clinics of Balsta and Knivsta and the Faculty of Odontology in Göteborg, Sweden Subjects : One hundred and sixty-four individuals, aged 60 years and older (mean age 71.5 years) who were considered to be at risk from caries. Design : The participants were randomly assigned either to: 1) rinse twice a day with a 0.05% NaF solution (n=49; rinsing group), 2) suck twice a day on a 1.66 mg NaF tablet (n=51; tablet group). 3) brush their teeth three times a day using a toothpaste slurry rinsing technique (n=32; slurry group), or 4) brush their teeth in their usual manner (n=32; control group). The participants in all 4 groups used a fluoride toothpaste (containing 0.32% NaF) at least twice daily. Results : No new carious lesions were found in 67% of the participants in the rinsing, 43% in the tablet, 25% in the slurry and 16% in the control group over the 2 years. The mean (± SD) 2-year caries increment was 0.8±1.4, 1.4±1.7, 1.9±1.9 and 2.3±2.1 DFS in the rinsing, tablet, slurry and control groups, respectively; it was significantly lower in the rinsing than in the control group (p<0.01). A lower incidence of DFS was also found in the tablet group than in the slurry group, but only for the lingual surfaces (p<0.05). Conclusion : The type of fluoride program may be of importance in the reduction of new caries lesions in an older population.