Journal of Indian Society of Pedodontics and Preventive Dentistry
Journal of Indian Society of Pedodontics and Preventive Dentistry
                                                   Official journal of the Indian Society of Pedodontics and Preventive Dentistry                           
Year : 2013  |  Volume : 31  |  Issue : 4  |  Page : 240--244

Comparative evaluation of the effects of xylitol and sugar-free chewing gums on salivary and dental plaque pH in children

Shikhar Kumar1, Suma H. P. Sogi2, KR Indushekar3,  
1 Department of Pediatric Dentistry, UCMS and GTB Hospital, Delhi, India
2 Department of Pediatric Dentistry, KLE University, Belgaum, Karnataka, India
3 Department of Pedodontics and Preventive Dentistry, Sudha Rastogi College of Dental Sciences & Research Institute, Faridabad, Haryana, India

Correspondence Address:
Shikhar Kumar
Department of Pediatric Dentistry, UCMS & GTB Hospital, Delhi - 110 095


This research paper primarily focuses on the importance of use of xylitol among school children. Purpose: The purpose of this paper is to evaluate the salivary and dental plaque pH changes after consumption of sugared and sugar-free (xylitol) chewing gums in children. Materials and Methods: A total of 30 school children were selected for this study and were divided into two equal groups and given both chewing gums for the experiment. Results: Children consuming the sugar-free (xylitol) chewing gum showed a marked increase in the pH of saliva and plaque when compared to their counterpart. All these values had a significant difference of P 0.0001. Conclusion: Xylitol is a safe all-natural sweetener which helps to reduce tooth decay. It plays a unique role in preventive strategies for better health.

How to cite this article:
Kumar S, Sogi SH, Indushekar K R. Comparative evaluation of the effects of xylitol and sugar-free chewing gums on salivary and dental plaque pH in children.J Indian Soc Pedod Prev Dent 2013;31:240-244

How to cite this URL:
Kumar S, Sogi SH, Indushekar K R. Comparative evaluation of the effects of xylitol and sugar-free chewing gums on salivary and dental plaque pH in children. J Indian Soc Pedod Prev Dent [serial online] 2013 [cited 2020 Sep 18 ];31:240-244
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Full Text

 Relevance of this Study To Jid

Xylitol has been proved to be an essential substitute to routine sugars. It not only helps in maintaining the pH of saliva and plaque, but also helps in reduction of oral microorganisms. The study will help in overall dental awareness among every individual and in all age group by creating an inclination toward sugar-free substitutes, i.e., xylitol.


Dental caries is a multifactorial disease in which diet plays a major etiologic factor. One of the most dominant roles is played by the ingestion of sugars in the caries etiology. Different strategies to combat caries have been used over the years. However, a prerequisite is that effective measures should be available and feasible for the high-risk individuals. [1]

Over the past few years, the prevalence of dental caries seems to have increased possibly as a result of more consumption of sugared items including sweets and other such products. Attempts to quit consuming high amounts of sugar also failed frequently. Xylitol has been used as a substitute for refined white sugar for more than 30 years. Xylitol has been approved by the Food and Drug Administration since the 1960's and is safe to use for children. Since then, it has been commonly used as a sweetener in various food and food products. [2]

It is thought to have an inhibitory action on the major causative bacteria in dental caries, Streptococcus mutans. [3] Xylitol can decrease lactic acid production in dental plaque, resulting in a higher plaque pH and can also promote an ecological shift, resulting in a less cariogenic environment. Xylitol is a common ingredient in sugar-free tablets, chewing gum, dentifrice, oral rinses and tooth pastes. Chewing gum with xylitol has received special attention, since mechanical cleaning, together with saliva stimulation, is very likely to give further benefits over and above the antibacterial effects of the polyol. [4]

The present study was done to know the variations in the pH of both saliva and dental plaque, before and after consumption of sugared and sugar-free (xylitol) chewing gums in children, which could further help in the reduction of caries formation.


To compare the salivary pH changes before and after consumption of sugared and sugar-free (xylitol) chewing gum.To compare the dental plaque pH changes before and after consumption of sugared and sugar-free (xylitol) chewing gum.

 Materials and Methods

The study was conducted in the Department of Pedodontics and Preventive Dentistry, KLE VK Institute of Dental Sciences, Belgaum. 30 school children were selected from the out-patient department between the age group of 10 and 12 years and equally divided into two different groups, Group A (15 children) and Group B (15 children). Group A children were subjected to sugared chewing gum (Happydent White Chewing Gum) and Group B children were subjected to sugar-free chewing gum (Happydent White Xylit Chewing Gum), manufactured by Perfetti Van Melle, Italy.

Inclusion criteria

Children whose chronological age was between 10 and 12 years with zero "dft" score.Children who were healthy (without any medical problems) and who were not under any kind of medications.

Exclusion criteria

Any child who did not fulfill any of the above criteria was excluded from the study.


An informed consent was obtained from the parents and ethical clearance was obtained prior to the start of the study. All children in Group A were first asked to report to the Department by 8:30 a.m., after finishing their daily routine of brushing and having breakfast. Oral prophylaxis was explained and then performed on all the children. The children were instructed not to practice any kind of oral hygiene measures for the next 48 h.

After 48 h, the children were again asked to report to the Department at 8:30 a.m. on an empty stomach, to avoid any kind of pH changes due to intake of food.

They were then asked to rinse their mouth with water for a minute to get rid of any food debris. They were then asked to expectorate the saliva (2 ml) in a sterile test tube. The desired volume (2 ml) of saliva was required so that the bulb of the measuring electrode could dip sufficiently into the saliva samples for pH measurements.

The saliva samples collected were then subjected for the pH measurements. The values displayed digitally were taken as control values.

Then, the plaque samples were collected from buccal and palatal surfaces of the maxillary teeth; and buccal and lingual surfaces of the mandibular teeth with the help of a sterile spoon excavator. These plaque samples were then dispersed in a test tube containing double de-ionized distilled water.

The dental plaque samples that were obtained were then subjected to pH measurements. The values displayed digitally were taken as control values.

Then the children were given 1 pellet of sugared chewing gum to chew for 10 min. After 10 min the chewing gum was discarded. The saliva and the dental plaque samples were then collected immediately by the same procedure as mentioned earlier and up to 1 h at a time interval of 15, 30and 60 min. Following this, the collected saliva and the dental plaque samples were subjected to pH measurements. The values displayed digitally were taken as experimental values.

After this, a thorough oral prophylaxis was done for all the children of Group A. The children were then given proper oral hygiene instructions and oral hygiene measures were reinforced in them. Similarly, the above mentioned entire procedure was carried out in all the selected 15 children of Group B (all the children were given 1 pellet of sugar-free chewing gum instead of sugared chewing gum).

The pH values were assessed with the help of a pH meter (Toshniwal Inst. Mfg. Pvt. Ltd. Ajmer) [Figure 1]. The pH meter was standardized using a standard protocol under the supervision of a pharmacy staff prior to pH measurement.{Figure 1}


In Group A (sugared chewing gum), there was a significant decrease in the pH of saliva and plaque samples [Table 1] and [Table 2]. All this value had a significant difference of P ≤ 0.0001. In Group B (sugar-free chewing gum), there was a significant increase in the pH of saliva and plaque samples [Table 3] and [Table 4]. All these values had a significant difference of P ≤ 0.0001.{Table 1}{Table 2}{Table 3}{Table 4}

Student's paired t-test was used to compare the pH values of saliva and plaque within the same groupand Student's t-test was used to compare the difference between both groups. Results showed a significant difference in both the comparisons.

A comparison was also made between Group A and Group B by using Student's t-test. There was no significant difference in the pH value at initial 2 time intervals. But later, as the time increased, there was a significant change in the pH [Table 5].{Table 5}


Chewing gums are made of natural or synthetic materials. The main constituent is the gum resin or the gum base. It also contains some amount of preservatives, flavoring and sweetening agents like sucrose (sugared chewing gums). The only exception can be of a sugar substitute, i.e., xylitol as a sweetening agent instead of sucrose. Clinical evidence shows that the use of sugar-free chewing gum does not lead to caries, presumably because the sugar substitutes used do not lead to the production in plaque of metabolic acids at a rate sufficient to cause a fall in pH and to attack the teeth. [5]

In addition, consumption of sugared chewing gum, on the other hand may lead to a rapid fall in the salivary and dental plaque pH leading to an increase in salivary microorganisms. Sugared chewing gums also leads to the addition of lots of calories [6] because the body is able to absorb these sweeteners, which are not possible with sugar substitutes (xylitol).

In another study, researchers had mothers chew xylitol gum 3 months after delivery until their children were 2 years old. The researchers found that children in the xylitol group had "a 70% reduction in cavities (dmf)". [7]

Xylitol has been used extensively to sweeten chewing gum and its properties have attracted considerable attention either as a bulk sweetener on its own or mixed with sorbitol in various proportions. It does not appear to be metabolized to form acid by any oral microorganism and indeed in vitro it is an antimetabolite, since on entering the cell it is phosphorylated to form an inhibitory compound. [8]

Xylitol in chewing gum is reported to reduce the proportions of mutans streptococci in plaque or saliva [9] and the amount of plaque [8],[10] present. Recent researches [11] confirms a plaque-reducing effect and suggests that the compound, having some chemical properties similar to sucrose, attracts and then "starves" harmful micro-organisms, allowing the mouth to remineralize damaged teeth with less interruption.

The results of this study tend to confirm the previous reports [12],[13] that consumption of sugar-free chewing gums (xylitol), over a period of time, leads to an increase in the alkaline pH of saliva and plaque from an acidic pH and thereby prevent decay to the teeth.

Park et al. reported the results of comparisons of the plaque pH effects of sugared and sugar-free chewing gum after an acidogenic challenge. Their preliminary report also suggested that when chewed for 20 min, both chewing gums reduced the fall in pH, but the sugar-free chewing gum was more effective than its counterpart. [14] The time for the collection of saliva was kept in the morning (8:30 a.m.) because there is a circadian variation in the flow rates of saliva from all the glands. The peaks of ion concentration are usually either in the early morning (6 a.m.-8 a.m.) or in the early evening (4 p.m.-8 p.m.). [15] So keeping that in mind, the time was kept in the morning to avoid any difficulty while collecting the saliva samples.

According to a study done by Dawes, the concentration of ions in the saliva keeps changing as the time progresses. Hence, in this study, saliva and dental plaque samples were taken at five different time intervals to record the variations in their pH values. [16] Another study has shown that both the chewing gums (sugar and sugar-free) can also enhance the remineralizing forces in the mouth leading to the repair of early white spot lesions. [17]

Previous studies [18],[19] have been done to assess the pH changes after consuming snacks or meals or juices only. But in the present study, there is a marked increase in the pH of saliva, only after chewing sugar-free chewing gum. Parallel studies [14],[20],[21] have been done to assess the reduction of S. mutans as a result of use of xylitol. There have been a universal agreement that the use of xylitol helps to prevent dental caries not only by increasing the pH of saliva and dental plaque, but also by reducing the number of salivary microorganisms present in the oral cavity.

Several studies [13] have shown that chewing gums containing xylitol can reduce caries incidence by a variable amount, when compared with a sucrose containing chewing gum or no chewing gum. Double-blind, placebo-controlled studies enrolling a total of almost 4000 children, have found that xylitol gum, candy or toothpaste can help prevent cavities. [22]

Holgerson et al. did a study [23] to investigate the short and long term effects of daily use of xylitol chewing gum on mutans streptococci and xylitol uptake in saliva. They found that consumption of xylitol could alter salivary microbial composition only during the intervention period, i.e., for a shorter period of time, but when consumed for longer time duration, i.e., for 6 months or more, there was no alteration in the salivary microbial composition.

Xylitol provides benefits in two ways as a sugar substitute and as an antimicrobial used at higher doses. It is non-acidogenic and non-cariogenic. When used properly, xylitol can help stop the formation of tooth decay (cariostatic). A recent study demonstrated that as a water additive for animals, xylitol was effective in reducing plaque and calculus accumulation in cats. [24]


As a means of caries prevention, xylitol chewing gum has proven to be a good way to promote dental health. Possibilities of further exploitation of these effects of sugar-free chewing gum, together with the specific benefits of xylitol, may offer hope in era of caries prevention and also add to the tools already available in prevention of caries formation.


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