Co-relationships between glandular salivary flow rates and dental caries.

OBJECTIVE: This study was designed to evaluate the relationship of age, gender, ethnicity and salivary flow rates on dental caries in an adult population using data collected from the Oral Health San Antonio Longitudinal Study of Aging (OH: SALSA). BACKGROUND: Saliva is essential to maintain a healthy oral environment and diminished output can result in dental caries. Although gender and age play a role in the quantity of saliva, little is known about the interaction of age, gender and ethnicity on dental caries and salivary flow rates. MATERIALS AND METHODS: Data from the 1147 participants in the OH: SALSA were analysed. The dependent variables were the number of teeth with untreated coronal caries, number of teeth with root caries and the number of coronal and root surfaces with untreated caries. The independent variables were stimulated and unstimulated glandular salivary flow rates along with the age, sex and ethnicity (e.g. European or Mexican ancestry) of the participants. RESULTS: Coronal caries experience was greater in younger participants while root surface caries experience was greater in the older participants. Coronal caries was lower in the older age groups while the root caries experience increased. Men had a statistically significant (p < 0.02) higher experience of root caries than women. Values for unstimulated and stimulated parotid salivary flow rates showed no age difference and remained constant with age, whereas the age differences in the unstimulated and stimulated submandibular/sublingual salivary flow rates were significant. The mean number of teeth with coronal and root caries was higher in Mexican-Americans than in European-Americans. CONCLUSIONS: Over one-fourth of the adults between the ages of 60 and 79 have untreated root caries over one-third having untreated coronal caries. Lower salivary flow rates play a significant role in both the number of teeth and the number of surfaces developing caries in these adults. Women and individuals of European-American ancestry experience less caries.

Effect of serotype 5 adenoviral and serotype 2 adeno- associated viral vector-mediated gene transfer to salivary glands on the composition of saliva.

Key to the development of a useful clinical therapy is the minimization of side effects. Routine safety testing, however, does not provide information about the physiological status of many potentially useful gene transfer target sites. In this study, we evaluated the longitudinal effects of intrasalivary duct delivery of recombinant serotype 5 adenoviral (rAd5; 10(9)-10(10) particles/gland in rats) and recombinant serotype 2 adeno-associated viral (rAAV2; 10(8)-10(9) particles/gland in mice) vectors on salivary composition. Both vectors led to modest, transient alterations in several salivary components that thereafter returned to normal. The changes suggested two initial specific consequences of rAd5 and rAAV2 vector administration: (1) a modest breach of the mucosal barrier in the targeted glands, indicated by elevations in salivary albumin, total protein, and Na+ levels, and (2) an innate host response, indicated by transient elevations in either salivary lactoferrin and IgA levels (rAd5) or mucin (rAAV2). These studies are consistent with the notion that administration of modest doses of rAd5 and rAAV2 vectors to salivary glands for a therapeutic purpose can be accomplished without severe or permanent injury to the target tissue, or compromise to its essential exocrine physiological function.

Distinct pathways of ERK activation by the muscarinic agonists pilocarpine and carbachol in a human salivary cell line.

Cholinergic-muscarinic receptor agonists are used to alleviate mouth dryness, although the cellular signals mediating the actions of these agents on salivary glands have not been identified. We examined the activation of ERK1/2 by two muscarinic agonists, pilocarpine and carbachol, in a human salivary cell line (HSY). Immunoblot analysis revealed that both agonists induced transient activation of ERK1/2. Whereas pilocarpine induced phosphorylation of the epidermal growth factor (EGF) receptor, carbachol did not. Moreover, ERK activation by pilocarpine, but not carbachol, was abolished by the EGF receptor inhibitor AG-1478. Downregulation of PKC by prolonged treatment of cells with the phorbol ester PMA diminished carbachol-induced ERK phosphorylation but had no effect on pilocarpine responsiveness. Depletion of intracellular Ca2+ ([Ca2+]i by EGTA did not affect ERK activation by either agent. In contrast to carbachol, pilocarpine did not elicit [Ca2+]i mobilization in HSY cells. Treatment of cells with the muscarinic receptor subtype 3 (M3) antagonist N-(3-chloropropyl)-4-piperidnyl diphenylacetate decreased ERK responsiveness to both agents, whereas the subtype 1 (M1) antagonist pirenzepine reduced only the carbachol response. Stimulation of ERKs by pilocarpine was also decreased by M3, but not M1, receptor small interfering RNA. The Src inhibitor PP2 blocked pilocarpine-induced ERK activation and EGF receptor phosphorylation, without affecting ERK activation by carbachol. Our results demonstrate that the actions of pilocarpine and carbachol in salivary cells are mediated through two distinct signaling mechanisms-pilocarpine acting via M3 receptors and Src-dependent transactivation of EGF receptors, and carbachol via M1/M3 receptors and PKC-converging on the ERK pathway.

Interaction of age and specific saliva component output on caries.

BACKGROUND AND AIMS: The purpose of this study was to explore the relationship between individual salivary components, dental caries and age, utilizing the data from the Oral Health: San Antonio Longitudinal Study of Aging (OH:SALSA). METHODS: The study population comprised a well-defined stratified sample of 811 dentate men and women. Subjects were divided into four age groups from 35 to 75+ years old. Unstimulated and stimulated submandibular/sublingual saliva flow rates, unstimulated and stimulated parotid saliva flow rates, total protein, 6 individual proteins and 4 inorganic constituents were measured. Specific salivary components were lactoferrin, secretory IgA, albumin, lysozyme, mucin, cystatin, K+, Ca2+, Na+ and Cl-. Caries measurements were the DMFT Index for crowns and for roots, Tooth Health Index for crowns and roots, Tooth caries, Root caries and Tooth restoration. The data on saliva components were square root transformed for linearity prior to analysis. Analysis was carried out in two stages. Partial correlation was performed, in order to identify significant relationships between specific salivary components and caries measurements, controlling for age group. In the second stage, using caries measurement as the dependant variable, the effects of age, flow rate and specific salivary component output (product of flow rate and concentration) were examined. RESULTS: Significant associations were found between caries, age and specific individual submandibular/sublingual salivary proteins (lactoferrin, albumin, lysozyme, mucin and cystatin) and specific inorganic constituents (K+, Ca2+, Na+ and Cl-). CONCLUSIONS: Changes in submandibular/ sublingual salivary component output during aging are correlated with high caries prevalence. These changes in saliva components over age may represent caries risk indicators.