Intra-Oral Variations in Total Plaque Fluoride Related to Plaque pH

Abstract

The aim of the present investigation was to study intra-oral variations in total plaque fluoride, and to examine whether such variations were related to plaque pH. Five orthodontic patients abstained from oral hygiene and daily fluoride rinsing for 2 days. Resting and fermenting plaque pH was measured with a touch micro-electrode at 14–21 localized sites on bonded vestibular tooth surfaces in each subject. Plaque samples from the same sites were analysed with a fluoride micro-electrode. A wide range of plaque pH values and fluoride concentrations were observed. In all subjects plaque pH and total fluoride levels were lower at upper than at lower front teeth. A direct log-linear relationship existed between total fluoride and fermenting plaque pH. In 4 of the 5 subjects this relationship was statistically significant (p < 0.05) and quite strong (adjusted R² 0.2–0.5, Beta 0.5–0.7). The study shows significant intra-oral variations in total plaque fluoride related to plaque pH.

Prevalence of cariogenic streptococci on incisor brackets detected by polymerase chain reaction

“…This could also explain why the maxillary incisors are more affected by enamel demineralization and white spot formation than the mandibular incisors during orthodontic treatment. 20 Two-way ANOVA showed no significant relationship between the prevalence of both streptococci and the oral hygiene indexes (Table II). This means that oral hygiene status was not strongly associated with cariogenic streptococci in this area.…”

“…This result is consistent with another study that showed that MS is more prevalent in the anterior region of the maxillary arch than in the mandibular arch. 20 This might be explained by the presence of major salivary glands, which clear the mandibular anterior portion more rapidly than the maxillary portion because of easy access of saliva. The maxillary anterior region is located far from the major salivary glands and appears to receive little saliva.…”

CaF₂ Formation: Cariostatic Properties and Factors of Enhancing the Effect

“…Such a slow-releasing CaF 2 could be beneficial in sites with low oral clearance. In such locations, a low pH may develop with a rapid loss of free fluoride and reduced long-term effect of topical fluoride application [Arneberg et al, 1997]. This offers a possible explanation of the high prevalence of white spot lesions on bonded upper anterior teeth in spite of regular fluoride exposure during fixed orthodontic therapy.…”

Effect of pH, fluoride and hydrofluoric acid concentration on ion release from NiTi wires with various coatings

“…Design of fixed orthodontic appliance enables retention of plaque which reflects in rapid change in microbial composition; with increase in acidogenic Streptococcus and Lactobacilles species 8,9) . Lactic acid is the metabolic product that keeps the pH of the plaque low (in 24 h plaque pH is 4.8) 9,10) ; also, during longer inactive periods (e.g.…”

“…Lactic acid is the metabolic product that keeps the pH of the plaque low (in 24 h plaque pH is 4.8) 9,10) ; also, during longer inactive periods (e.g. sleeping) the pH of saliva is below 5, as well as after food intake (increase in bacterial metabolism also causes drop of the pH of saliva below 5) 11,12) .…”