Evaluation of stress biomarkers and electrolytes in saliva of patients undergoing fixed orthodontic treatment.

BACKGROUND: The aim of this study was to test the hypothesis that treatment with orthodontic appliances evokes significant functional limitations and emotional stress, which can be detected by salivary biomarkers. METHODS: Twenty subjects (10 men and 10 women) who underwent orthodontic treatment were included in this prospective study. Saliva was sampled for detection of alpha-amylase activity and cortisol levels at three different times: before bracket placement (T0), 24 hours after archwire placement (T1), and 30 days after archwire placement (T2). The saliva electrolytes concentrations of calcium, phosphorus, magnesium, sodium and potassium were also evaluated. Moreover, the possible functional limitations of the appliances were evaluated by a masticatory performance test and pain experience registration. All variables were compared with those in a control group with normal occlusion. RESULTS: The orthodontic patients exhibited a significant increase in emotional stress as detected by the alpha-amylase activity at T1, the period in which patients reported the higher values of pain and exhibited the lower masticatory performance indices. The basal salivary cortisol was not affect by the treatment and the main change detected in electrolyte concentration was a sodium reduction, when these patients were compared to controls. CONCLUSIONS: The present data indicate that orthodontic patients are under emotional stress only during the period of higher pain experience, which could also disrupt the masticatory performance. However, these alterations were not correlated with a single measurement of stress-related biomarkers in saliva, suggesting that these solitary endocrine measurements are not adequate to predict the temporary pain and masticatory limitation experimented by patients undergoing orthodontic treatment.

In situ Effect of Arginine-Containing Dentifrice on Plaque Composition and on Enamel Demineralization under Distinct Cariogenic Conditions.

There is limited evidence that arginine-containing fluoridated dentifrices (AFD) have a better anticaries effect than regular fluoridated dentifrices (FD), especially in subjects at a higher risk for caries development. This study aimed to assess the effect of AFD on enamel demineralization and on the microbial and biochemical compositions of biofilm formed under different frequencies of sucrose exposure. It consisted of an in situ split-mouth design, where 12 adult volunteers who used FD for at least 2 months prior to the beginning of this study wore acrylic palatal appliances containing 4 bovine enamel specimens (1 pair at each side of the appliance) during 2 phases of 14 days each. FD slurry (3×/day) and 20% sucrose solution (4× and 8×/day) were dripped on the specimens during the first experimental phase. The same volunteers then used AFD during a 2-month washout period, followed by a second experimental phase where the AFD slurry and sucrose solution were applied onto a new subset of specimens. The percentage of enamel surface hardness loss (%SHL), the lesion depth (LD), the integrated mineral loss (IML), microbial counts on biofilms, the biomass, and inorganic and insoluble extracellular polysaccharide (IEPS) biofilm concentrations were determined. Higher %SHL, biomass, and IEPS and lower fluoride values were found at sucrose 8×/day exposure. Lower IEPS were found in the presence of AFD compared to FD. Similar %SHL, LD, and IML values were found between FD and AFD, irrespectively of the cariogenic challenge. The results suggest that AFD have an anticaries effect similar to that of regular FD.

Salivary secretory IgA concentration and dental caries in children with Down syndrome.

PURPOSE: To evaluate the relationship between salivary secretory immunoglobulin A (sIgA) concentration and dental caries in children with Down syndrome (DS) and compare it with findings in non-DS children. METHODS: The sample comprised 61 DS children and 52 non-DS children, aged 6 to 14 years. Caries experience, plaque index (PI), and gingival bleeding index (GBI) were recorded. Saliva samples were collected from all children. Total salivary sIgA concentrations were determined using an enzymatic assay method. RESULTS: Caries experience in primary and permanent dentitions were similar in DS and non-DS children. However, PI and GBI values were significantly lower in DS compared to non-DS children. DS children had higher salivary sIgA concentrations compared to non-DS children. No difference in sIgA concentration was observed between children with and without caries experience in either group. CONCLUSIONS: DS children have higher salivary sIgA concentrations than non-DS children. However, this finding did not correlate with caries experience in the study population.

Cariogenic Potential of Sucrose Associated with Maltodextrin on Dental Enamel.

Maltodextrin is a hydrolysate of cornstarch and has been widely used in the food industry associated with sucrose. The addition of starch can increase the cariogenic potential of sucrose; however, there are sparse data regarding the cariogenicity of sucrose associated with maltodextrin. Therefore, the aim of this study was to test in situ if maltodextrin could increase the cariogenic potential of sucrose. This was an in situ, randomized, crossover, split-mouth, and double-blind study. Volunteers wore palatal appliances containing bovine enamel blocks for 2 periods of 14 days. They dripped the following solutions on the enamel blocks 8 times per day: deionized distilled water (DDW), maltodextrin (M), sucrose + maltodextrin (S+M), or sucrose (S). At the end of each experimental period, biofilms were collected and analyzed for microbiological (mutans streptococci, lactobacilli, and total microorganisms counts) and biochemical (calcium, inorganic phosphate, fluoride, and insoluble extracellular polysaccharides concentrations) compositions. The enamel demineralization was assessed by microhardness. Treatments S and S+M resulted in a lower inorganic composition and higher concentration of insoluble extracellular polysaccharides in the biofilms, and higher enamel mineral loss compared to DDW and M. It can be concluded that the cariogenic potential of sucrose is not changed when this carbohydrate is associated with maltodextrin (dextrose equivalent 13-17).

Impact of Bariatric Surgery on the Saliva of Patients with Morbid Obesity.

BACKGROUND: The oral condition of obese patients may change following bariatric surgery owing to adverse effects that cause alterations in the oral cavity. The aim of this study was to evaluate the impact of bariatric surgery on the saliva of patients with morbid obesity. METHODS: Whole saliva samples were collected from 27 patients with morbid obesity (BMI >40 kg/m(2)), prior to and 6 months after bariatric surgery. Stimulated salivary flow rate, pH, buffering capacity, and microbial levels of mutans streptococci, Lactobacillus spp., and Candida albicans were analyzed from saliva. RESULTS: Values of all salivary variables before and after bariatric surgery were within the normal range, except for the level of C. albicans, which was elevated at both times. An increase in the level of mutans streptococci was observed after bariatric surgery (p < 0.05). CONCLUSIONS: The results suggest that the salivary levels of mutans streptococci increase following bariatric surgery in morbidly obese patients.

Biochemical composition of carious dentin and different layers of sound dentin.

The aim of this study was to evaluate the concentrations of calcium (Ca), inorganic phosphate (Pi) and fluoride (F) in carious dentin and in different layers of sound dentin. The samples examined were 52 permanent teeth (26 sound and 26 carious), which were subjected to two experiments to assess the mineral content of: 1) two layers (internal and external) of sound dentin and 2) sound and carious dentin. Ca and Pi were analyzed using a colorimetric method with arsenazo III (C22H18As2N4O14S2) and molybdate reagents, and F was analyzed using a specific electrode. A non-parametric test, the Mann-Whitney test, was used to verify differences between groups. Sound dentin showed a higher concentration of fluoride in the internal layer than in the external layer (P = 0.03), but no inter-layer differences in Ca or Pi concentration were evident. Lower concentrations of Ca, Pi and F were observed in carious dentin than in sound dentin (P < 0.05). The results of this study suggest that the internal layer of sound dentin has a higher fluoride content than the external layer, and that carious dentin has lower concentrations of Ca, Pi and F than sound dentin.

Effect of the widespread use of fluorides on the occurrence of hidden caries in children.

BACKGROUND: It has been suggested that the widespread use of fluorides could interfere in the prevalence of clinically undetected occlusal dentine caries. AIM: The objective of this study was to determine the role of public water fluoridation and fluoride dentifrice on the prevalence of hidden caries in 8-10-year-old children. DESIGN: Clinical and radiographic data on schoolchildren collected in an epidemiologic study in Porto Alegre, Brazil, at two moments, 1975 (n = 228) and 1996 (n = 213), were analysed. Only the first permanent molars were studied. Only children of the 1996 examinations had benefited from fluoridated water soon after birth and had regular access to fluoride dentifrices. The criterion applied for hidden caries, when data from 1975 to 1996 were compared, was clinical sound surfaces that presented a radiolucent zone in the dentine. RESULTS: The prevalence of clinically sound surfaces and percentage of hidden caries was 0.51 and 26.4% in 1975 and 2.67 and 12.9% in 1996, respectively. The prevalence of hidden caries differed statistically between the two periods (P < 0.05). CONCLUSIONS: The results do indicate that the widespread use of fluoride via public water supply and dentifrices decreases the prevalence of hidden caries.