Denis M. O'Mullane

Comparison of the efficacies of disinfectants to control microbial contamination in dental unit water systems in general dental practices across the European union

ABSTRACT Water delivered by dental unit water systems (DUWS) in general dental practices can harbor high numbers of bacteria, including opportunistic pathogens. Biofilms on tubing within DUWS provide a reservoir for microorganisms and should be controlled. This study compared disinfection products for their ability to meet the American Dental Associations guideline of <200 CFU · ml−1 for DUWS water. Alpron, BioBlue, Dentosept, Oxygenal, Sanosil, Sterilex Ultra, and Ster4Spray were tested in DUWS (n = 134) in Denmark, Germany, Greece, Ireland, The Netherlands, Spain, and the United Kingdom. Weekly water samples were tested for total viable counts (TVCs) on yeast extract agar, and, where possible, the effects of products on established biofilm (TVCs) were measured. A 4- to 5-week baseline measurement period was followed by 6 to 8 weeks of disinfection (intermittent or continuous product application). DUWS water TVCs before disinfection ranged from 0 to 5.41 log CFU · ml−1. Disinfectants achieved reductions in the median water TVC ranging from 0.69 (Ster4Spray) to 3.11 (Dentosept) log CFU · ml−1, although occasional high values (up to 4.88 log CFU · ml−1) occurred with all products. Before treatment, 64% of all baseline samples exceeded American Dental Association guidelines, compared to only 17% following commencement of treatment; where tested, biofilm TVCs were reduced to below detectable levels. The antimicrobial efficacies of products varied (e.g., 91% of water samples from DUWS treated with Dentosept or Oxygenal met American Dental Association guidelines, compared to 60% of those treated with Ster4Spray). Overall, the continuously applied products performed better than those applied intermittently. The most effective products were Dentosept and Oxygenal, although Dentosept gave the most consistent and sustained antimicrobial effect over time.

A lacticin 3147 enriched food ingredient reduces Streptococcus mutans isolated from the human oral cavity in saliva

Aims:  To isolate and characterise Streptococcus mutans from Irish saliva samples and to assess their sensitivity to a food‐grade preparation of the lantibiotic, lacticin 3147, produced by Lactococcus lactis DPC3147.

Critique of the review of 'Water fluoridation for the prevention of dental caries' published by the Cochrane Collaboration in 2015.

The Cochrane Review on water fluoridation for the prevention of dental caries was published in 2015 and attracted considerable interest and comment, especially in countries with extensive water fluoridation programmes. The Review had two objectives: (i) to evaluate the effects of water fluoridation (artificial or natural) on the prevention of dental caries, and (ii) to evaluate the effects of water fluoridation (artificial or natural) on dental fluorosis. The authors concluded, inter alia, that there was very little contemporary evidence, meeting the Reviews inclusion criteria, that evaluated the effectiveness of water fluoridation for the prevention of dental caries. The purpose of this critique is to examine the conduct of the above Review, and to put it into context in the wider body of evidence regarding the effectiveness of water fluoridation. While the overall conclusion that water fluoridation is effective in caries prevention agrees with previous reviews, many important public health questions could not be answered by the Review because of the restrictive criteria used to judge adequacy of study design and risk of bias. The potential benefits of using wider criteria in order to achieve a fuller understanding of the effectiveness of water fluoridation are discussed.

Fluoride And Caring for Children’s Teeth (FACCT): Clinical Fieldwork Protocol

Background: The reduction in dental caries seen between Irish national surveys of children’s oral health in 1984 and 2002 was accompanied by an increase in the prevalence of enamel fluorosis. To minimise the risk of enamel fluorosis in Irish children, in 2007, the level of fluoride in drinking water was reduced from 0.8-1.0 ppm to 0.6-0.8 ppm fluoride. Recommendations on the use of fluoride toothpastes in young children were issued in 2002. Fluoride and Caring for Children’s Teeth (FACCT) is a collaborative project between the Oral Health Services Research Centre, University College Cork and the Health Service Executive dental service, with funding from the Health Research Board. Aim: FACCT aims to evaluate the impact and the outcome of the change in community water fluoridation (CWF) policy (2007) on dental caries and enamel fluorosis in Irish schoolchildren, while also considering the change in policy on the use of fluoride toothpastes (2002). Methods/Design: A cross-sectional study with nested longitudinal study will be conducted in school year (SY) 2013-2014 by trained and calibrated dental examiners in primary schools in counties Dublin, Cork and Kerry for a representative sample of children born either prior to or post policy changes; age 12 (born 2001) and age 5, (born 2008). Five-year-olds will be followed-up when they are 8-year-olds (SY 2016-2017). The main explanatory variable will be fluoridation status of the children (lifetime exposure to CWF yes/no). Information about other explanatory variables will be collected via parent (of 5-, 8- and 12-year-olds) and child completed (8- and 12-year-olds only) questionnaires. The main outcomes will be dental caries (dmf/DMF Index), enamel fluorosis (Dean’s Index) and oral health-related quality of life (OHRQoL). Multivariate regression analyses will be used to determine the impact and outcome of the change in CWF policy on oral health outcomes controlling for other explanatory variables.

Strong association between water fluoride concentration and proportion of the population with dental fluorosis

Objective Does water fluoridation have negative effects? This objective was broken down into four sections: fluorosis, bone fracture and bone development effects, cancer, and other possible adverse effects.Data sources See page 37.Study selection A total of 88 studies met the inclusion criteria for fluorosis. All studies were level C, except one of level B. The mean validity score was only 2.8 out of 8.0.Data extraction and synthesis Because the studies used different indices to assess fluorosis, the percentage prevalence of fluorosis was the outcome of interest. Regression analysis was used to investigate the association of water fluoride level with the prevalence of dental fluorosis. A multilevel model was used to combine studies.Results Regression analysis showed a significant dose–response relationship for both methods of measuring the prevalence of fluorosis. The pooled estimate of the prevalence of fluorosis and fluorosis of aesthetic concern are shown in the Table 1 below.A rough approximation of the number of people who would have to be exposed to water fluoride levels of 1.0 ppm when compared with 0.4 ppm for one additional person to develop fluorosis of any level is six [95% confidence interval (CI), 4–21—the number needed to harm (NNH)]. This rises to 22 (95% CI, 14–28) for fluorosis of aesthetic concern. A sensitivity analysis of the regression analysis was conducted in which all data-points above 1.5 ppm were excluded it was suggested that the higher water fluoride levels could potentially force the regression line to show a relationship that may not actually exist for the lower levels of fluoride. The proportions predicted by this model are similar to the initial analysis but with wider CI (Table 2).An increase in the prevalence of fluorosis over time was not seen in this analysis of water fluoridation studies. While this finding is counterintuitive, no explanation is evident from the data.Conclusions These results show a strong association between water fluoride concentration and the proportion of the population with dental fluorosis.

Fluoride supplements useful but increase the risk of mild fluorosis

Objectives To investigate whether the regular use of fluoride supplements in non-fluoridated communities during the period of tooth development increases the risk of dental fluorosis.Data sources Medline search 1966–Sept 1997 (English only papers) using following key words: fluorosis, dental, fluoride, fluoride supplement or supplements, drop or drops, and tablet or tablets.Study selection Twenty-four studies that assessed the development of dental fluorosis in children who had used fluoride supplements were identified. Ten cross-sectional/case control studies and four follow-up studies had data that allowed a quantitative estimation of the risk of developing dental fluorosis in users of fluoride supplements. Ten studies were excluded.Results A consistent and strong association between the use of fluoride supplements and dental fluorosis was found. Meta-analyses of the cross-sectional/case-control studies estimated the odds ratio of dental fluorosis in users of fluoride supplements between 2.1 and 2.3 (95% C.I. 1.5–3.4).Conclusions In non-fluoridated communities, the use of fluoride supplements during the first 6 years of life is associated with a significant increase in the risk of developing a very mild to mild type of dental fluorosis.