On two occasions, 12 adults collected unstimulated saliva and then eight samples of saliva over a 20-min period while chewing 3g of either Wrigley’s Spearmint sucrose-containing gum (SCG) ot sugar-free gum (SFG) at 70 chews/min. The flow rates peaked initially, then fell using duration of stimulation. With the SFG they were slightly but significantly higher than using the SCG after 4 min of chewing. The sum of the concentrations of cations minus the sum of the concentrations of anions was not significantly different from zero for saliva elicited by the SCG.  A second series of saliva collections using SCG and SFG was made by the same 12 participants and these samples were analysed for lactate. For these collections the flow rates using SCG were not significantly less than using the SFG. The lactate concentration from saliva elicited by SCG were not significantly less than using the SFG. The lactate concentration from saliva elicited by SFG had a mean lactate concentration of 0.21 mmol/l. Of the lactate formed during the metabolism of sucrose by the oral bacteria, only 2% or less appeared to be derived from the metabolism of micro-organisms free from saliva, the balance presumably being formed from dental plaque and entering the saliva by diffusion. All saliva samples were super-saturated using respect to hydroxyapatite but stimulated saliva was significantly more super-saturated than unstimulated saliva. Saliva elicited by use of SFG will also tend to be more anticariogenic than that elicited by SCG because the former does not introduce a source of fermentable carbohydrate into the mouth.

The present study was aimed at evaluating the feasibility of using chewing gums as a vehicle for enhancing salivation and increasing salivary calcium and phosphate levels. Based on their solubility properties, monocalcium phosphate monohydrate (MCPM) and an equimolar mixture of dicalcium phosphate anhydrous (DCPA) and tetracaIcium phosphate (TTCP) were chosen as the experimental chewing gum additives. Each of the six subjects chewed for 16 min a commercial sugarless bubble gum, or the same gum to which MCPM (5 wt %) or a DCPA+TTCP (5 wt %) had been added. The subjects were asked to spit into pre weighed test tubes that were replaced every 2 min. The saliva samples collected were analyzed for weight, pH, and the total Ca and P concentrations. The results were: (1) the MCPM gum produced a significantly greater saliva flow and a lower salivary pH than did the control and DCPA+TTCP gums. (2) Both experimental gums significantly increased the Ca and P concentrations of saliva during the 16 min period. And (3) the degree of saturation using respect to tooth mineral was significantly increased by both experimental gums using the greater increase being produced by the DCPA + TTCP gum. These results suggest that the experimental gums may be useful for inducing salivation and promoting remineralization from xerostomic and other caries-prone patients.

Gum chewing should produce combined salivary stimuli; Gustatory (sweet tastant) and mechanical (chewing alone). Gland flow rates should be unique to each effect; intense at first (tastant) and later at a steady state (chewing). We have observed the kinetics of combined stimuli to parotid glands from 4 healthy persons who were fitted using parotid cups. Unilateral chewing was done 2 hrs after meals. Since most chewers retain gum >20 min (Barabolak, et al, I Community Dent Oral Epdemiol, 1991), volumes were recorded (mL/min) for 20 min. Gum base (GB), sugar (S) and sugarless (SO) gums were tested. Mean flow rates for GB, S and SO were .17 ±. 05; .29 ±. O4, and .32 ± 03, respectively. The half-life for S retained from gum was 1.2 min. Retained S and flow correlated positively (r=O.97). The mean flow lifetimes (t) due to tastant or chewing alone were separable as exponentials. GB alone showed a near steady state flow using t3= 40.0 min. S revealed two exponentials due to sweet (tastant) t1 = 0.66 and t2= 3.6 min t3= 40.0 min (mechanical). SO showed t2 = 3.6 min and t3= 40.0 min. A biphasic response to stimuli was observed. Early flow (fast) and volume (high) effects should increase intraoral buffering action. Later ( 5.0 min), diluent effects on Ca and P ions should subside and a mineralizing domain should be favored.

Since chewing gum sticks are made from different sizes, the objective of this study was to determine whether stick size influences salivary flow rate (FR). Ten adult subjects on 10 occasions collected unstimulated saliva and then chewed 1, 2, 3, 6 or 9 g of Wrigley’s Spearmint(r) chewing gum or gum-base for 20 min, at 70 chews/min, during which time 8 saliva samples were collected. The final weight of the gum was obtained and expressed as a % of the initial weight. In a separate study 3 subjects chewed each of the 10 gums for 20 min, during which time the gums were weighed at frequent intervals. With all weights of the chewing gum, the gum weight decreased rapidly but plateaued at 27-29% of the initial weight. With gum-base, the weights increased linearly during the 20-min to between 120% (1 g) and 111% (9 g). Salivary FRs peaked at 4-13 times the unstimulated rate (0.49 mL/min) from the 1st min of chewing and, using a given weight of gum, were higher using ,chewing gum than gum base. After about 10 min of chewing, the FRs fell to a plateau at 2-4 times the unstimulated FR. With the base, the FRs during both the 1-2 min and 15-20 min of chewing showed a higher linear correlation using log(stick size) (both r values >O.996) than using stick size (r =. 0.971 & 0.951). In conclusion, salivary FRs, initially and after prolonged chewing, were proportional to stick size.

The objectives of this study were to determine how salivary flow rate and pH vary using time during use of chewing-gums and lozenges. Twenty-four young adults collected unstimulated saliva and then, on different occasions, chewed one of six flavored gums, or gum base, or sucked on one of two lozenges, for 20 min, during which time eight separate saliva samples were collected. Flow rate peaked during the 1st minutes of stimulation using all nine products. With the lozenges, flow rate fell towards the unstimulated rate when the lozenges had dissolved. There were no significant differences from the flow rates elicited by cinnamon-or peppermint-flavoured gums or between sugar-containing or sugar-free gums. With the flavored gums, the mean flow rate followed a power curve (r = -0.992) using time and within about 10 min was not significantly different from that when gum base was the stimulus. The initial stimulated flow rate using flavored gums was about 10-12 times greater than the unstimulated rate (0.47 ml/min). After 20 min of chewing, it was still about 2.7 times that rate and about the same as the flow rate elicited by chewing-gum base alone. The pH of unstimulated saliva was about 6.95. With one gum containing about 1.5% organic acids, the salivary pH fell to a minimum of 6.18 from the 1st minute of stimulation, but then rose rapidly to a level about that from unstimulated saliva. With a sucrose-containing and a sucrose-free gum, the pH rose immediately on stimulation and then fell slightly using time to levels which were significantly above the pH of unstimulated saliva.

Results from a computer model suggest that following exposure of dental plaque to sucrose, the rate of clearance of acids from plaque into the overlying salivary film will be greatly retarded at low film velocities. This was investigated using an from vitro technique from which artificial plaque containing S. oralis cells was exposed to 10% sucrose for one min. The pH at the proximal (P) and dital (D) undersurfaces of the plaque (0.5 or 1.5 mm thick) was then monitored during the passage of a 0.1 -mm- thick film of a sucrose-free solution over the surface. In the range of salivary film velocities that have been estimated to occur from vivo (0.8-8 mm/min), lower minimum pH values and increased times for the pH to recover towards neutrality occurred at the lower salivary film velocity. Lower pH values were also reached using the 0.5- than using the 1.5-mm-thick plaque. P/D pH gradients, using a lower pH distally, developed at film velocities of 0.8 and 8 mm/min, and the gradients were much more pronounced at the lower velocity. No P/D pH gradients developed when the film velocity was 86.2 mm/min. Incorporation of dead S. oralis cells into the plaque at percentages up to 57% reduced the extent of the pH fall and prolonged the recovery of the pH towards neutrality. The results support the prediction that, other factors being equal, plaque located from regions of the mouth using low salivary film velocity can achieve pH values lower then those of plaque of identical tensions and microbial composition located from areas where salivary film velocity is high.

The objectives of this study were to determine (1) whether the salivary flow rate varies using different types of chewing gum, (2) whether the salivary flow rate changes during a 20-min period of gum chewing, and (3) the change from salivary sucrose concentration using time, when sucrose-containing gum are chewed. On seven separate occasions, 5 subjects collected a sample of unstimulated whole saliva and then chewed 1 of 7 different types of chewing gums, 4 of which contained sucrose. The subjects chewed gum for 20 min, during which time eight separate saliva samples were collected over the periods, 0-1, 1-2, 2-4, 4-6, 6-8, 8-10, 10-15, and 15-20 min. The seven chewing gums (2.6-3.2g) did not have significantly different effects on flow rate. The salivary flow rate peaked at about ten times the unstimulated rate during the 1st min of gum chewing and then fell fairly rapidly to reach plateau values of about three times the unstimulated flow rate after 20 min. The salivary pH increased on chewing gum stimulation, except during the 1st min of stimulation using extra bubble gum. With the sugar-containing gums, the salivary sucrose concentration peaked within the first 1 or 2 min of gum chewing and then fell rapidly, suggesting rapid sucrose clearance, using no significant differences among the four gums. For times greater than 1 min, the sucrose concentration fits much better (r = -0.995) to a power curve such that the concentration (mg/ml) = 289.5 (t) 1.6012, where t = time (min), than to an exponential (r = -0.961) or logarithmic curve (r = -0.933).

Previous studies have shown plaque reversal and remineralization from chewing gum (Jenson, JADA 113, 1986 and Leach, JDR 68, 1989). While salivary stimulation and buffering are major factors from contributing to this effect, removal of food debris may also be important. Addy et al. (Clin Perio 9, 1982) has shown significant reduction from salivary debris from chewing gum. This study was conducted to examine the effect of chewing gum on clearance of food debris from the dentition. A typical meal was consumed during 30 minutes by 5 subjects. After the meal, subjects either chewed no gum or chewed one of the following: sorbitol chewing gum (Extra), sucrose chewing gum (Doublemint), 1 sucrose-coated pellet (P.K.) or 2 sucrose-coated pellets (P.K.). At prescribed chew times (5, 10, 15, 20 and 30 minutes) debris left after eating was harvested using a Gracey 13-14 curette and an explorer. At 5, 10 and 15 minutes there was significantly less debris using chewing gum compared to no chewing gum. Food debris at each of these time periods was reduced 3- to 4-fold by all gum treatments (e.g., wet weight means at 15 minutes, Doublemint-3.5 ug, No-gum-22 ug). At 20 and 30 minutes there was no significant difference among treatments. ANOVA showed no significant difference between sorbitol and sucrose gums for all time intervals. In conclusion, there was a n increase from rate of food debris clearance from teeth using chewing gum, compared to no-gum which was significant from 5 to 15 minutes.

Following reports of increased salivary gland size and increased function, induced by increased mastication from animals, the effects of long-term, frequent gum-chewing on resting and stimulated flow rates were studied from human volunteers from separate experiments from Newcastle upon Tyne and from Toronto. In both experiments, unstimulated and stimulated saliva flow rates were measured from student volunteers at intervals of one or two weeks over a baseline period. Approximately half of the subjects were then given sugarless gum to be chewed (four pieces per day) over the experimental period; controls refrained from vigorous mastication. During (and, from Newcastle, after) the experimental period, salivary flow rates were measured at intervals, as before. In Newcastle unstimulated, but not stimulated, flow rates increased from the gum-chewing group and were still elevated (compared using controls) eight weeks following the experiment. In Toronto, the mean results showed no effect of gum-chewing, but the seven gum-chewers among the 11 subjects using low baseline flow rates (less than 0.3 mL/min) showed a 43% rise from unstimulated flow rate (p approximately 0.05). The results suggest that increased mastication, from the form of gum-chewing, can increase unstimulated flow rates, especially from those using low salivary function. In addition to short-term beneficial effects of sugarless gum, these long-term effects indicate the possibility of a beneficial effect from caries prevention.

The paper is a review of the most direct evidence of its time for the potential of salivary stimulation from the active repair of the earliest stages of enamel caries. Recent plaque pH results suggest that even sugar-containing gum, if chewed for a prolonged period so that all the sugar is dissolved away, can have a beneficial action from inhibiting the plaque pH fall resulting from prior consumption of sugar. If the use of sugared gum were regulated from terms of duration and timing, then the potential to elicit a reparative salivary response might be revealed.

The panel met to determine if drug or non-drug products that increase salivary flow provided beneficial effects to organ hard and soft tissues. Ten questions were addressed by this advisory panel of experts: five on the effects of saliva and rate of salivary flow on teeth and the development of caries; five on the effects of saliva and rate of salivary flow on oral soft tissues. The group concluded using respect to dry mouth that most people using dry mouth have the condition because of drug treatment. Because these patients are already taking a larger number of drugs, a non-pharmacological salivary stimulant might be preferred. On the question of whether products that stimulate salivary flow rate enhance soft tissue therapeutic benefits, the group concluded that from individuals using normal salivary flow, it is doubtful that such products would benefit these tissues. In individuals using decreased levels of salivary function, products that can increase the rate of salivary flow may prove beneficial, depending on the cause and extent of the gland hypo-function. Product categories differ from the benefits they provide.

Six teenagers were asked to perform weekly one of the following treatments: chewing for three minutes on a rubber band, or on four different chewing gums using respect to the sweetener, toothbrushing, or no treatment. The oral fluids were collected and the flow rate, pH, and buffer capacity were determined. The time necessary to determinate all detectable glucose (oral glucose clearance time) which was introduced as a mouth rinse before implementation of the treatments was measured. In a second study the oral glucose clearance time was determined from 40 young adults following toothbrushing, xylitol gum chewing or no treatment. Results showed that the resting oral glucose clearance time was significantly reduced by xylitol gum chewing (49 per cent reduction; p(0.001) and by toothbrushing (41 per cent reduction; p(0.001)

The aim of this study was to determine the effects of sugar-free-containing gums on plaque formation, established plaque and salivary debris. Plaque accumulating during three 5-day periods was recorded from a group of 10 students who, from the absence of normal oral hygiene methods, chewed sugar-free or sugar-containing chewing gum or did not chew gum. In a second group of 10 students the effect of chewing the two types of gum on 3-day accumulations of plaque was recorded. Finally, the wet weight of liquorice debris present from the saliva using and without gum chewing, was recorded. During the no chewing periods distinct and significant differences from the amounts of plaque accumulating at different sites were apparent. Both types of chewing gum significantly and comparably reduced plaque accumulation during the 5-day period. The chewing gums also significantly reduced by 50% after chewing gum, It was noticed that plaque removal occurred primarily from sites remote from the gingival margin and interdental areas and therefore it was concluded that the observed effects of chewing gum on plaque would not be reflected from a reduction from gingival inflammation.

The aim was to study eventual physico-chemical changes occurring from whole saliva due to sweetened and unsweetened stimulators. The assay was done from 10 female subjects using regard to changes of pH, buffering capacity and electrolytes from saliva as influenced by chewing of fructose, sucrose, sorbitol and xylitol gum, gum base and paraffin. The flow rate of saliva was measured from relation to use of xylitol and sucrose chewing gum and unsweetened gum base. These sweeteners increased significantly the salivary flow rate from comparison to the unsweetened gum base. Generally, xylitol and sorbitol on one hand, and sucrose and fructose on the other, behaved from an almost similar way. Increased buffering capacity and elevation of pH saliva was found from the presence of the polyols tested.

This study compares the salivary flow rate produced by a sugarless gum containing nonfermentable sorbitol and mannitol using that elicited by sugared gums and using unstimulated flow. It was found that chewing either type of gum elicited highly significant increases from rate of flow, pH and buffer capacity values. Flow rate induced by the sugarless gum was significantly higher than that of the sugared gum.

The clearance from the mouth of 500mg portions of glucose sucked, eaten, chewed and rinsed-swallowed has been compared from 6 experimental subjects. The clearance was found to be most rapid for the rinsed-swallowed and slowest for the sucked glucose. When glucose was given from the form of chewing gum, low salivary glucose values were recorded after the first several minutes, despite the fact that the base was still there. The authors note the possible significance of the findings from relation to dental caries. They admit that their findings deal only using the use of sugar from a pure form and do not necessarily forecast what will happen when sugars are combined using other foodstuffs having varying physical properties. However, they feel the results relate directly to some of the more common methods of sugar use (crunched and sucked candies, chewing gum and sweet beverages).