Source 30

To date, the most dependable mode of plaque control is mechanical cleaning with a toothbrush and other oral hygiene aids.1 Unfortunately, the majority of people are unable or unwilling to realize the need to spend time to remove plaque adequately from all tooth surfaces.2 Barnes et al.3 suggested that chewing-gum may serve as an effective oral hygiene device when brushing may not be possible. Sugar-free gums are simple, inexpensive and are readily available. Studies have shown that daily chewing-gum has beneficial effects. It increases salivary flow, raises the pH of plaque and saliva,4,5 reduces oral malodor6 and is effective for stain removal.7 Very few studies have examined the antiplaque effect of sugar-free chewing-gum and the results of these studies were variable. Some studies showed the antiplaque effect of chewing-gum,3,8,9 but other studies suggested that chewing sugar-free gum can reduce occlusal plaque but has no plaque inhibitory effect on smooth surfaces.10–12 Imfeld4 stated that chewing-gum can result in some reduction of debris, but little or no reduction of plaque. Variations on study design and methodology, as well as on the composition of the tested chewing-gum make it difficult to support or refute the antiplaque property of chewing-gum.
Fundamentally, the use of dental floss or interproximal brush appears to provide an adjunct effect on interdental hygiene when associated with tooth brushing.13 However, the main problems with all interdental cleaning methods are the individuals manual dexterity and motivation.14,15 For that reason, there is a tendency to look for other simpler options for cleaning interdental areas.
There is little information in the literature regarding the effect of gum chewing on interdental debris indicating that this topic remains unexplored. However, one study tried to assess the effect of chewing gum on salivary debris by having volunteers chew liquorice cakes and, after 10 minutes, collecting saliva samples with and without chewing the gum. A 50% reduction in the wet weight of liquorice debris in the saliva was recorded post-gum chewing.11 For the chewing-gum studies, the trend has been to study the preventive action10 of the gum in the absence of tooth brushing and other oral hygiene practices employing a 4 or 5 day plaque regrowth model.12–14 The results of these studies were disappointing and showed no significant antiplaque effect on the buccal and lingual surfaces. Hence, it was felt that there is a need to study the effect of chewing-gum as an adjunct to tooth brushing and also to assess the therapeutic action of the chewing-gum on established plaque and interdental debris.
The aim of the study was to evaluate the effect of chewing sugar-free gum in addition to tooth brushing on dental plaque and interdental debris. The null hypothesis was that chewing sugar-free gum after meals in addition to tooth brushing would not effectively remove dental plaque and interdental debris.
Brushing is the most effective method in cleaning the teeth. Nevertheless, toothbrush can remove only 71-86% of deposits from tooth surfaces and 60-74% from the accessible proximal surfaces.17 Hence, this study was conducted to evaluate whether chewing sugar-free gum twice a day after meals can add any supplemental value to brushing the teeth in reducing surface plaque and interdental debris. At the end of study, half of the null hypothesis was accepted; this half stated that chewing sugar-free gum after meals along with daily tooth brush has no effect on established plaque. But, the second half of null hypothesis (no effect of chewing sugar-free gum on interdental debris) was rejected. The absence of anti-plaque effect of chewing gum on buccal and lingual surfaces is in consensus with the earlier study reports.10–12 The participants in these studies had to refrain from daily brushing their teeth and used only chewing-gum as an oral hygiene aid. This suggests that chewing a piece of gum alone or as an adjunct to brushing the teeth is not beneficial for reducing the plaque. However, the anti-debris result is in consensus with the study done by Addy et al.11 Given the fact that most people brush for only one minute or less18,19 and the use of interdental cleansing aids have reduced patients’ compliance,13 effective dental plaque removal from proximal surfaces of teeth does not seem to be realistic for most people. Thus, under these circumstances, chewing a piece of gum can serve as an effective adjunct along with brushing to have the interdental spaces free from debris. The small difference between interdental debris scores at the end of control phase (B10) and ten days after chewing gum (T11) was not significant and probably over a period of time as the individual is used to chewing, the difference could be significantly larger.
The interesting outcome of this study that chewing gum was effective in removing the interdental debris but not the established surface plaque, supports the idea that the debris which is loosely bound in the interdental spaces, might be removed by the increased salivary flow which is stimulated by chewing the gum4,5 but that is not true for dental plaque, which is firmly adhered to the tooth surface. Ozcan et al.7 indicated that as the bolus of gum is softened by chewing and moved around the mouth, its texture and mechanical action may reduce the plaque and pellicle and thus, stain formation. Recalling that only one pellet of gum was used and considering the gum shrinkage while chewing, there is a possibility that the small-sized gum bolus hampered the mechanical property of plaque removal in our study. Hence, this may be indicative that for effective mechanical action of plaque removal by the gum, more than one pellet are needed to be chewed at a time. Holgerson et al.9 and Mouton et al.20 have previously confirmed the antiplaque effect of chewing gum. They conducted their study with a kind of sugar free gum containing xylitol as a sweetener which is an active ingredient unlike aspartame used as the sweetener in the present study. It is shown that xylitol reduces the formation of dental plaque and inhibits the growth of streptococcus mutans. It is non-cariogenic and can decrease lactic acid production in dental plaque which results in higher pH of the plaque.4,9 However, whether this difference in the gum base has been attributed to the absence of an anti-plaque effect in this study, remains unanswered and needs confirmation with future comparative studies.
The novel approach of this study was to evaluate the effect of chewing gum on interdental debris accumulation, which has not been done earlier. Also, a self-designed interdental debris index was used in this study. This index is simple and provides consistent results since evaluation is based on binary system: presence or absence of the debris. In previous studies, authors used Oral Hygiene Index-Simplified which is the best suited assessment tool for assessment of debris and calculus.9 The assessment tool for plaque used in the present study was Personal Hygiene Performance Index (PHP-M). Though the assessment is based on only 6 index teeth, it can yield reliable data in evaluating the difference in visible plaque; its well defined criteria for both tooth selection and scoring make it an index that can be determined fairly rapidly and consistently.16
One can question why a randomized control cross-over study with a wash out period was not a chosen study design and why there was a difference in the duration of study phase and that of control phase? However, considering the time limitation, the best suitable study design was chosen; a non-randomized, controlled before and after study design (here the study group was its own control), which eliminated virtually all group differences21 and gave the advantage of 24 participants for both study and control groups vis-à-vis 12 participants in the study and control groups, if the study was a randomized controlled trial in the ideal setting. The compliance in the study was good. On personal communication with the participants, it was noted that chewing the gum after meals produced a fresh feeling in the mouth. They also reported an increased salivary flow in their mouths. None of them reported any serious adverse effects like muscle fatigue or pain in their temporomandibular joints after chewing the gum for 30 minutes twice a day. There was no control over the individual chewing style (chewing force, chewing frequency and unilateral or bilateral chewing) which can influence the study results. The sample was a cohort of dental students, whose oral hygiene can be considered more superior compared to the general population and hence, this may reduce the external validity of the study. This was a short term evaluation study and only one brand of the chewing gum was used. Hence, the results need to be carefully interpreted.

Within the limits of the present study, the results of this short term evaluation study indicated that chew chewing sugar-free gum after meals, in addition to daily tooth brushing reduced the interdental debris but had no effect on buccal and lingual established plaque.

It is interesting that gum that brushing and chewing gum after a meal can reduce interdental debris. I thought that this might be good for a developing country because gum is cheap, easily accessible, and often desired. The only downside is that chewing gum or water rinsing does not reduce the plaque count in the mouth. It sounded like a good alternative in a country that may not be accustomed to brushing their teeth, but it looks like gum chewing will not make the cut.