Saliva characteristics, diet and carioreceptivity in dental students

The use of sugar by dental plaque microorganisms leads to acid formation from the bacteria metabolism, which determines a decrease of pH onto teeth surfaces. The value of the critical pH is 5.2-5.5. We aimed to evaluate the capacity of patients to change their diet towards caries prevention after acknowledging the values of saliva parameters (pH, buffer capacity).

A group of 52 subjects were clinically examined according to the International Caries Assessment and Detection System protocol. They were required to complete a diet questionnaire and salivary tests were made for the oral mucosa hydration level, pH, buffer capacity, salivary flow rate at rest and upon stimulation. 4 pre-calibrated 6th year students and 2 dentists performed the tests and the ICDAS examination. One week after the tests, the subjects were asked to complete the diet questionnaire again. The studied group consisted of students aged between 23-26 years, randomly selected among 6(th) year students of the Faculty of Dentistry from Cluj-Napoca.

The mean DMF-S index was 18.39. Most of the patients (65%) had a DMF-S index between 9 and 21. Just 2.5% had an index of 3, which was the lowest value recorded. 5% of the patients had a DMFS of 35, which was the maximal value recorded. The distribution of DMF-S was normal. 50% of the patients had no active caries. Even though most subjects (19.23%) had a pH within the normal interval, most of them were at the bottom value of the interval (6.8). Most subjects had a pH of 6.4, which is moderately acid. The mean pH was 6.7, therefore, a moderately acid one. The Pearson correlation coefficient between DMFS and pH was 0.255. A mild negative correlation (-0.275) was found between the cariogenic food and buffer capacity. A week later we noticed a statistically significant decrease of cariogenic foods and drinks in students with acid pH and with low buffer capacity.

A regular intake of cakes, bonbons and chocolate was reported by subjects who had a high DMF-S value and a low saliva buffer capacity. Only after the patients were aware of their caries risk, did they change their diet towards a non-cariogenic one, even though they had had the theoretical knowledge regarding caries prevention for at least 3 years. We conclude that the use of the chair-side salivary test should be highly recommended for cario-receptive patients.