Expulsion mechanism of xylitol 5-phosphate in Streptococcus mutans

The expulsion mechanism of xylitol 5-phosphate in Streptococcus mutans ATCC 25175 was studied using resting cells incubated in the presence of 14 C-xylitol. The expulsion appeared to be a two-step process: xylitol 5-phosphate was first hydrolyzed to xylitol and inorganic phosphate, and the xylitol was subsequently expelled from the cells. The dephosphorylation step appeared to be energy-requiring and it was most likely associated with a phosphatase which was active on xylitol 5-phosphate. Two to three successive cultivations of the cells in the presence of 6% xylitol increased this enzyme activity 4.3-fold. These results are in accordance with the presence of an energy-dependent xylitol 5-phosphate cycle in S. mutans , which is regulated by exogenous xylitol.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71776/1/j.1600-0722.1990.tb00949.x.pd

Oral health and orofacial pain in older people with dementia: a systematic review with focus on dental hard tissues

Objective: The aim of this review was to provide a systematic overview including a quality assessment of studies about oral health and orofacial pain in older people with dementia, compared to older people without dementia. Methods: A systematic literature search was performed in PubMed, CINAHL, and the Cochrane Library. The following search terms were used: dementia and oral health or stomatognathic disease. The quality assessment of the included articles was performed using the Newcastle-Ottawa Scale (NOS). Results: The search yielded 527 articles, of which 37 were included for the quality assessment and quantitative overview. The median NOS score of the included studies was 5, and the mean was 4.9 (SD 2.2). The heterogeneity between the studies was considered too large to perform a meta-analysis. An equivalent prevalence of orofacial pain, number of teeth present, decayed missing filled teeth index, edentulousness percentage, and denture use was found for both groups. However, the presence of caries and retained roots was higher in older people with dementia than in those without. Conclusions: Older people with dementia have worse oral health, with more retained roots and coronal and root caries, when compared to older people without dementia. Little research focused on orofacial pain in older people with dementia. Clinical relevance: The current state of oral health in older people with dementia could be improved with oral care education of caretakers and regular professional dental care