Salivary flow rate

Single local dose of 5-20 Gy to various salivary glands Dose-dependent decrease in salivary flow rate and sodium composition of saliva at 10 Gy and higher, changes were irreversible 46... 

Stimulation of saliva production is under sympathetic and parasympathetic control. Parasympathetic stimulation produces a serous watery secretion, whereas sympathetic stimulation produces much thicker saliva. Drug delivery systems, therefore, should not be placed over a duct or adjacent to a salivary duct, as this may dislodge the retentive system or may result in excessive wash-out of the drug or rapid dissolution/erosion of the delivery system making it difficult to achieve high local drug concentrations. If a retentive system is placed over salivary ducts, the reduced salivary flow rate may produce less or no mucus which is required for the proper attachment of a mucoadhesive delivery device. 

Reuterving CO, Reuterving G, Hagg E, Ericson T. Salivary flow rate and salivary glucose concentration in patients with diabetes mellitus influence of severity of diabetes. Diabetes Metabolism 1987, 13, 457 -62. 

Lu, C., L.C. Anderson, M.S. Morgan and R.A. Fenske (1997b). Correspondence of Salivary and Plasma Concentrations of Atrazine in Rats under Variable Salivary Flow Rate and Plasma Concentration, J. Toxicol. Environ. Health, 52, 317-329. 

The astringency sensation is felt differently by different tasters (Gawel et al. 2001) probably due to differences in individuals saliva, namely its protein composition (Lesschaeve and Noble 2005 Horne et al. 2002). Recently, a study concerning the characterization of basic PRPs in thirteen normal adults has demonstrated that the protein IB9 was only detected in nine adults saliva, while IB7 was not detected at all (Messana et al. 2004). The salivary flow rate was also described as a factor that varies between subjects and can affect astringency perception (Lesschaeve... 

Yarat A, Akyiiz S, Koc L, Erdem H, EmekU N. Salivary sialic acide, protein, salivary flow rate, pH, buffeming capacity and caries indices in subjects with Down s syndrome. J. Dent. 1999 27 115-118. 

A major portion of saliva is composed of water (99%) and has a pH of 6.5-7.S depending on the flow rate and location.An increase in the salivary flow rate leads to the secretion of watery saliva. Stimulated salivary secretion affects the film thickness and aids in easy migration of test compounds from one region of the mouth to another. Salivary pH is also important because passive diffusion of unionized drug is the major mechanism of oral absorption. ... 

Consensus Oral health effects of products that increase salivary flow rate. J Amer Dent Assoc 1988 116 757-759. 

Rampant caries group (RC group) DMFT > 15, who had significantly reduced salivary flow rate and had received radiation therapy or were patients diagnosed with Sjogren s syndrome. All patients complained of a dry mouth. 

CP group generally healthy with normal salivary flow rate, DMFT > 10, with active caries. 

Lacomte P, Dawes C The influence of salivary flow rate on diffusion of potassium chloride from artificial plaque at different sites in the mouth. J Dent Res 1987 66 1614-1618. 

Very little research has been carried out on the rates of diffusion of substances into or from dental plaque in vivo. Primosch et al. (1986) studied topical fluoride distribution in the oral cavity and rates of clearance following different methods of dissolution of fluoride tablets. They found that after the chewing, sucking, or passive dissolution of the tablets, fluoride was not evenly distributed in the mouth, and that retention of fluoride was reduced by increased salivary flow rate. Thus, it would seem likely that the rate of renewal of the film of saliva over plaque must influence diffusion rates into and from plaque. 

The half-times in the mouth varied with locations and with salivary flow rate, as shown in Fig. 5 When the flow rate was unstimulated, the shortest halftimes occurred in the LALi site and the longest in the UAB site. In both groups, the difference was significant at... 

Fig. 5. Half-time when salivary flow rate is unstimulated...

Nursing bottle caries (Fig.6) is a specific form of rampant decay on the buccal surface of the upper anterior primary teeth. Some etiological factors, such as the types of microorganisms, tooth structure, and diet, have been reported, but there is little information about the influence of the salivary flow rate. 

Very little research has been carried out on the salivary flow rate or salivary clearance in children. Although the average thicJcness of the salivary film covering teeth and oral mucosa in children is essentially identical with values reported for adults, marked differences were found between children and adults for such parameters as unstimulated and stimulated whole-salivary flow rates, the volume of saliva in the mouth before and after swallowing, and the surface area of the mouth. 

Mean unstnnulated salivary flow rates were 0.47 0.2 ml/min. 

Table 1. Half-times (mean + SD) and salivary flow rates when salivary flow was unstimulated...

Effect of salivary flow rate on fluoride retention in the mouth 2.4.1 Aim... 

Salivary clearance rates in different parts of the mouth are known to vary. The clearance half-times on the buccal surfaces of the upper anterior teeth were the longest of any site in the mouth. These show that the saliva secreted into the oral cavity is not perfectly mixed. Weatherell et al (1986) reports the difference by the fluoride distribution in the mouth after fluoride rinsing. Duckworth and Morgan (1991) and Heath et al. (2001) have also reported oral fluoride retention after use of fluoride rinse. These researches demonstrate the mechanism of the salivary clearance reported by Dawes (1983). According to Lear et al (1965), the salivary flow rate in the sleep is almost similar to the zero, but there are few reports the clearance of the fluoride in the sleep. 

Fig. 14. An extraoral device for salivary flow rate study.

Heath, K, Singh, V., Logan, R., McIntyre. J.(2001). Analysis of fluoride levels retained intraorally or ingested following routine clinical applications of topacal fluoride products. Australian Dental Journal, Vol.46, No. 1, pp.24-31, ISSN 00450421 LagerlSf, F., Dawes, C.(1984). The volume of saliva in the mouth before and after swallowing, Journal of Dental Research, Vol.63, No.5, p>p. 618-621, ISSN 0022-0345 Lecomte, R, Dawes, C.(1987).The influence of salivary flow rate on diffusion of pwtassium chloride from artificial plaque at different sites in the mouth. Journal of Dental Research, Vol.66, No.ll, pp.1614-1618, ISSN... 

Watanabe, S. Dawes, C.(1992) Salivary flow rate and salivary film thickness in five-year-oldchildren. Journal of Dental Research, Vol.69, No.5, pp. 1150-1153 0003-9969... 

Eating disorders are also associated with tooth erosion [112], Specifically, buUinic patients are likely to suffer from erosion, with the palatal surfaces of the maxillary incisors, canines and pre-molars being most serious affected [113], This is because of their behavioural pattern of regurgitating food, which is acidified by strong acid from the stomach (HCl). Bulimics, who are typically young females, generally have low salivary flow rates, and are frequently found to have increased tooth sensitivity both to low temperatures and to touch [113],... 

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