OBJECTIVES: Considering that Galla chinensis extract (GCE) solution has a low pH, which might dissolve dental enamel, we investigated the effects of elevation of pH on GCE stability, and on its anti-caries properties. DESIGNS: Stability of GCE solutions, either in H(2)O (pH less than 4.0) or when buffered at pH 5.5, 7.0 and 10.0, was assessed from UV-VIS spectra. Inhibition of enamel demineralization was determined in a pH-cycling set up, comprising treatments with either GCE solutions or negative control buffers and acid and neutral buffer immersions. Demineralization was assessed by calcium in the acetate buffers. To determine antimicrobial properties, polymicrobial biofilms were formed after saliva inoculation on glass surfaces which were treated after 48 h. Treatment output parameters were lactic acid formation and viability, the latter by colony forming unit (CFU) counts. RESULTS: At pH 7.0 and higher GCE solutions changed colour and absorption spectra in UV-VIS, indicative of chemical changes. Regarding enamel demineralization, significant inhibitions (P<0.05) were found for all GCE treatments when compared with corresponding controls. In polymicrobial biofilms, GCE reduced the acid production, compared with the negative controls (P<0.05). However, this difference was only significant at the lower pH values. CONCLUSIONS: GCE solutions were unstable under neutral and alkaline conditions. pH did not significantly influence the inhibiting effect of GCE on enamel demineralization. However, GCE was not effective on polymicrobial biofilms at alkaline pH (8.5). To avoid enamel damage due to acidic treatment, GCE solutions should be used at about pH 5.5.
OBJECTIVES: Considering that Galla chinensis extract (GCE) solution has a low pH, which might dissolve dental enamel, we investigated the effects of elevation of pH on GCE stability, and on its anti-caries properties. DESIGNS: Stability of GCE solutions, either in H(2)O (pH less than 4.0) or when buffered at pH 5.5, 7.0 and 10.0, was assessed from UV-VIS spectra. Inhibition of enamel demineralization was determined in a pH-cycling set up, comprising treatments with either GCE solutions or negative control buffers and acid and neutral buffer immersions. Demineralization was assessed by calcium in the acetate buffers. To determine antimicrobial properties, polymicrobial biofilms were formed after saliva inoculation on glass surfaces which were treated after 48 h. Treatment output parameters were lactic acid formation and viability, the latter by colony forming unit (CFU) counts. RESULTS: At pH 7.0 and higher GCE solutions changed colour and absorption spectra in UV-VIS, indicative of chemical changes. Regarding enamel demineralization, significant inhibitions (P<0.05) were found for all GCE treatments when compared with corresponding controls. In polymicrobial biofilms, GCE reduced the acid production, compared with the negative controls (P<0.05). However, this difference was only significant at the lower pH values. CONCLUSIONS:GCE solutions were unstable under neutral and alkaline conditions. pH did not significantly influence the inhibiting effect of GCE on enamel demineralization. However, GCE was not effective on polymicrobial biofilms at alkaline pH (8.5). To avoid enamel damage due to acidic treatment, GCE solutions should be used at about pH 5.5.
Authors: Xuelian Huang; Christopher M Browngardt; Min Jiang; Sang-Joon Ahn; Robert A Burne; Marcelle M Nascimento Journal: Caries Res Date: 2017-12-20 Impact factor: 4.056
Authors: Xuelian Huang; Sara R Palmer; Sang-Joon Ahn; Vincent P Richards; Matthew L Williams; Marcelle M Nascimento; Robert A Burne Journal: Appl Environ Microbiol Date: 2016-01-29 Impact factor: 4.792
Authors: Xuelian Huang; Meng Deng; Mingdong Liu; Lei Cheng; R A M Exterkate; Jiyao Li; Xuedong Zhou; Jacob M Ten Cate Journal: Open Dent J Date: 2017-08-31