Statistical analysis of salivary pH changes after the intake of black tea and yerba maté supplemented with sweeteners.

Many studies have demonstrated the effect of various beverages on hard tissues of the mouth. Sugar consumption has also been avoided because it is associated with caries activity, and artificial sweetener research has been promoted. In this paper, data about the buffer capacity of black tea and yerba mate supplemented with sugar or one of two artificial sweeteners (Barny diet and NutraSweet) were examined. Salivary pH variations after the ingestion of both infusions were statistically analysed. A factorial design of four variables (Infusion, Sweetener, Concentration and Time) and their effects were considered independently and combined. The addition of sucrose lowered the pH of the infusions while black tea showed a greater buffer capacity than yerba mate. Significant differences (p < 0.0001) were obtained when salivary pH values were compared between infusions supplemented with sugar or artificial sweeteners. When a factorial design was used to examine differences between Barny diet and NutraSweet, no significant two- or three-way interactions could be observed. This statistical analysis showed a small significant variation in salivary pH after the ingestion of black tea or yerba mate with sugar but not with artificial sweeteners at the recommended concentrations.

Analysis of dental health education activity carried out by dentistry students.

During their career, students of dentistry acquire techniques which they will employ later on their patients. Since the health of these patients and society itself cannot be left exclusively to the professional activity of these future dentist, an experimental extra-class experience was carried out with pupils from primary and secondary schools. The students gave the pupils presentations on Nutrition, Calcium and Phosphorus and Caries. The aim of this study was to evaluate: a) the influence of society on the teaching process, and training during the first university year, and b) epidemiologic aspects. Our results indicated that 32.2% of the primary and 15.6 % of the secondary school pupils were unfamiliar with the disciplines presented by the students. According to the evaluations 78.1% of the primary and 94.0% of the secondary school pupils achieved or exceeded the minimum requirements considered necessary for correct nutritional and oral health habits. Evaluations of the students demonstrated that the students who had participated in the activity did not have knowledge superior to that of non-participating students. Therefore this experience can be considered an exercise in utilizing human resources for primary prevention rather than an innovative methodology which improves the teaching-learning process. It also seems recommendable in view of the low cost of the exercise.

Effect of lactobacilli and antibiotics on E. coli urinary infections in mice.

Urinary antibiotic treatments usually affect the normal urethral flora. This work was developed in order to evaluate whether Lactobacillus fermentum CRL 1058 could reduce urinary tract infections (UTI) produced by uropathogenic Escherichia coli in mice treated with antimicrobial agents. Animals were inoculated intra-urethrically with agarose beads containing lactobacilli, and were challenged with E. coli. Ampicillin (13 mg/kg/dose) was administered orally. The number of microorganisms present at different days was evaluated in the urogenital tract. Serum inflammatory and systemic immune response were also registered. The use of 5 doses of ampicillin after 3 doses of lactobacilli in agarose beads significantly affected the viability of lactic acid bacteria, while the amount of E. coli was not altered. Lactate dehidrogenase (LDH) activity and anti-E. coli antibody levels showed no statistically significant difference between the challenged and non-challenged mice. Lactobacilli reinoculation and 3 doses of ampicillin proved to be a moderately effective treatment since a smaller amount of E. coli was recovered from the organs of treated mice than from the controls. The reinforcement of lactobacilli, administered on the 9th day, produced a faster elimination of the pathogen. The ampicillin dose used allowed lactobacilli permanence in the urinary tract, and caused the elimination of the pathogen. Serum LDH values seemed to show an inflammatory immune response. No successful preventive results could be achieved. We can conclude that lactobacilli and adequately low doses of ampicillin have a positive effect on the treatment of E. coli in this UTI model.