|Year : 2015 | Volume
| Issue : 4 | Page : 549-552
A comparative study of long-term effect of tobacco on resting whole mouth salivary flow rate and pH
Sabarni Chakrabarty, Shilpa Patil, Satheesha Reddy Hanumantha Bandalore, Ramamurthy Thyganareddy Kempegowda, Shivu, Shubha Pewa
Department of Oral Medicine and Radiology, AECS Maaruti College of Dental Sciences and Research Centre, Bengaluru, Karnataka, India
|Date of Submission||14-Sep-2015|
|Date of Acceptance||10-Mar-2016|
|Date of Web Publication||19-Aug-2016|
Dr. Sabarni Chakrabarty
Santara Magan Place, Flat No 01, Princess Block, Hulimavu Tank Bund Road, Doddakamanahalli, Bengaluru 560 076, Karnataka
Source of Support: None, Conflict of Interest: None
| Abstract|| |
Introduction: The taste receptors responsible for salivary secretion are constantly being affected by the harmful by-products of tobacco, and it is believed that tobacco usage on a long-term basis can decrease the sensitivity of taste receptors leading to decreased salivary reflex. It is hypothesized that long-term tobacco usage might lead to altered taste receptors' response, changing the salivary flow rate (SFR). Unstimulated whole mouth SFR and salivary pH play an important role in the causation of various oral changes and conditions. Aims: The aim of this study is to determine the effects of long-term use of tobacco on SFR and salivary pH and the oral and dental health among tobacco chewers, smokers, and control group. Settings and Design: Cross-sectional study. Materials and Methods: The study comprised a total of 90 patients who were grouped into smokers (group A), smokeless tobacco chewers (group B), and controls (group C). Each group consisted of 30 healthy male adults. Resting whole mouth saliva was collected from every patient; SFR was calculated and then salivary pH was assessed using the salivary pH strips, depending on the color change of the indicator paper strip when compared with a color chart. Statistical Analysis Used: Data were analyzed using the Statistical Package for Social Service (SPSS) computer software. Student's t-test, analysis of variance (ANOVA), and Z-test were applied to assess between-group differences. Results: The mean (±SD) SFR was found to be 0.77 (±0.23) ml/min for group A, 0.63 (±0.16) ml/min for group B, and 1.08 (±0.08) ml/min for group C, and on comparing the groups, the result was significant. The mean (±SD) pH was found to be 6.8 (±0.20) for group A, 6.65 (±0.30) for group B, and 7.06 (±0.23) for group C and was also found to be significant on comparison. Conclusions: It is concluded from this experimental study on long-term tobacco users that smokeless and smoked forms of tobacco adversely affect salivary reflex, salivary secretion, and salivary pH, with the smokeless form being more harmful than the smoked form of tobacco. The effect of tobacco on long-term usage can lead to vulnerable changes in the oral mucosa and dental structures.
Keywords: Salivary flow rate, salivary pH, tobacco
|How to cite this article:|
Chakrabarty S, Patil S, Bandalore SR, Kempegowda RT, Shivu, Pewa S. A comparative study of long-term effect of tobacco on resting whole mouth salivary flow rate and pH. J Indian Acad Oral Med Radiol 2015;27:549-52
|How to cite this URL:|
Chakrabarty S, Patil S, Bandalore SR, Kempegowda RT, Shivu, Pewa S. A comparative study of long-term effect of tobacco on resting whole mouth salivary flow rate and pH. J Indian Acad Oral Med Radiol [serial online] 2015 [cited 2020 Sep 22];27:549-52. Available from: http://www.jiaomr.in/text.asp?2015/27/4/549/188759
| Introduction|| |
Salivary fluid is an exocrine secretion of the three pairs of salivary glands, namely, the parotid, the submandibular, and the sublingual, along with that of numerous minor salivary glands.  It is an important body fluid consisting of a variety of constituents which play an essential role in maintaining oral health. It is necessary for growth and maturation of taste buds, protection and lubrication of the oral mucosa, maintenance of integrity of enamel by tooth remineralization, stimulation, dilution, and cleaning, pH balance, and phonation.  It has been used as a source of non-invasive investigation of various body parameters as it is the most easily accessible fluid in the human body. 
Various drugs such as antihypertensives, anticholinergics, diuretics, psychoactive substances, antihistaminics, and conditions such as nutritional, metabolic, neurological abnormalities, and post surgery alter the salivary constituents, thereby altering the salivary parameters like salivary flow rate (SFR), buffering capacity, and salivary pH.  Early diagnosis and intervention are required in various oral, pharyngeal, and esophageal disorders; neoplastic, metabolic, nutritional, inflammatory, genetic, and autoimmune conditions; and disorders of the nervous system, which can affect the salivary gland function. ,
Unstimulated whole saliva is a mixture of secretions that enter the mouth without any exogenous stimuli.  Unstimulated whole SFRs were found to be about 0.3-0.5 ml/min in healthy individuals, , whereas stimulated SFR can be as high as 10 ml/min. Usually, the SFRs are 0.3 ml/min when unstimulated, but rise to 1.5-2.0 ml/min when stimulated, and the flow rate is negligible during night. ,
It is believed that tobacco usage on a long-term basis can decrease the sensitivity of taste receptors, leading to decreased salivary reflex. It is hypothesized that long-term tobacco usage might lead to altered taste receptors' response, changing the SFR. Unstimulated whole mouth SFR and salivary pH play an important role in the causation of various oral changes and conditions. ,,, Nicotine is the main ingredient of tobacco which leads to altered secretion of saliva by acting on specific cholinergic receptors in the brain and other organs and causing neural activation.  Few studies have shown an increase in SFR in the short-term usage, but the long-term effect of tobacco use on pH and SFR is still not clear. So, this study was carried out to assess the effects of long-term tobacco usage on pH and SFR in tobacco chewers and smokers compared with controls.
| Materials and Methods|| |
The subjects of the study were selected from the patients visiting AECS Maaruti College of Dental Sciences and Research Centre, Bangalore and institutional ethical committee approval was obtained before commencement of the study. The study had been conducted over a period of 10 months. Subjects in the present study comprised healthy adults who were divided into three groups (30 in each group). Groups A and B comprised subjects consuming tobacco for 5-7 years or more.
Group A: Smoke form (30 males)
Group B: Smokeless form (30 males)
Group C: Healthy control (30 males).
The subjects were matched with respect to age (20-45 years) and the duration of smoking (5-7 years or more). The exclusion criteria were age over 45 years, alcohol consumption, consumption of tobacco in a combined form (smoke and smokeless form), history of any other habits, history of radiotherapy to the head and neck region, patients with systemic or salivary gland diseases or under any medications, history of trauma to the head and neck, denture wearers, and patients with any oral lesions. Each subject was briefed about the procedure before sampling and asked to wash his mouth gargling with plain water. ,,, Then a written informed consent was taken from each patient and a case history was taken which was followed by a careful oral examination. Unstimulated whole mouth saliva was then obtained from each patient and SFR was calculated in ml/min for 5 min and salivary pH was determined using specific salivary pH strips. 
Saliva was collected between 9:00 a.m. and 12:00 p.m. to avoid diurnal variation. The patients were asked not to eat, drink, or rinse their mouth or smoke or chew 1 h before and during the entire procedure. After seating the patients in the dental chair, they were instructed to spit in a graduated container continuously for 5 min. Patients were requested not to speak or swallow during the procedure.
After saliva collection, the SFR was measured and the mean SFR was calculated in ml/min. Then, salivary pH was measured using specific salivary pH indicator strips as follows. After measuring the SFR, unstimulated whole mouth saliva was taken in a watch glass and the specific indicator strip was dipped in it and pH was assessed depending on the color change of the indicator paper strip when compared with a color chart. The instructions of the manufacturer were followed while measuring salivary pH. The corresponding value was considered as the salivary pH. 
| Results|| |
The subjects in our study were in the age group 20-45 years. The mean age (±SD) in group A was 32.6 (±5.27), in group B was 32.06 (±5.58), and in group C was 31.96 (±6.88); on comparing the groups, a non-significant difference was obtained (F = 0.101, P = 0.903). Subjects of groups A and B consumed tobacco for 7 years or more, with the mean (±SD) duration, consumption, and frequency of habit being 9.75 (±3.24), 9 (±4.17 pieces/day), and 7 (±0.68) in group A and 10.12 (±2.75), 2 (±0.2 packets/day), and 8 (±0.60) in group B, respectively.
The mean (±SD) SFR was found to be 0.77 (±0.23) ml/min for group A, 0.63 (±0.16) ml/min for group B, and 1.08 (±0.08) ml/min for group C, and on comparing the groups, the result was significant. The mean (±SD) pH was found to be 6.8 (±0.20) for group A, 6.65 (±0.30) for group B, and 7.06 (±0.23) for group C and was also found to be significant on comparison. So, a significant relation was obtained when the mean salivary pH [Table 1] and Graph 1 and the mean SFR [Table 1] and Graph 2 were compared between the groups [Table 2].
|Table 1: Individual comparison of age, salivary flow rate (ml/min) for 5 min, and salivary pH between the groups |
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|Table 2: Comparison between the salivary flow rate (ml/min) for 5 min and salivary pH |
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| Discussion|| |
The salivary flow and composition alter greatly under different conditions as salivary secretion is a complex process.  The salivary flow and protein secretion in unstimulated whole saliva depend on the sizes of the parotid and submandibular glands, i.e. the larger the sizes of the glands, the faster will be the salivary flow and protein secretion. It is hypothesized that the salivary secretion from the glands is generally elicited in response to stimulation of the autonomic innervations to the glands or because of the drugs mimicking the actions of autonomic innervations. 
Saliva, being the first biological fluid, is exposed to the harmful constituents of tobacco, both smoked and smokeless forms, which leads to various structural and functional changes. The taste receptors responsible for salivary secretion are constantly being affected by the harmful by-products of tobacco.  Saliva is composed of various glycoproteins, peptides, electrolytes, and lipids having antioxidant, antimicrobial, buffering, remineralization of tooth, and tissue repair activities.  Therefore, altered unstimulated whole mouth SFR and salivary pH have an important role in the causation of various oral changes and conditions. 
In our study, the mean (±SD) SFR was found to be 0.77 (±0.23) in group A, 0.63 (±0.16) in group B, and 1.08 (±0.18) in group C. On comparing the groups, a significant result was noted (F = 39.47114785, P = 8.209E-13). The noticeable decrease in SFR in group A and group B patients is most likely because of the effect of nicotine on the taste nerve apparatus.  Khan et al. noticed that some patients developed tolerance to the long-term effects of smoking.  Some studies also have shown that cigarette smoking would cause a noticeable short-term increase in SFRs, whereas the long-term effects of tobacco use are still not clear. 
In our present study, it was observed that the mean (±SD) salivary pH of whole saliva was 6.8 (±0.20) in group A, 6.65 (±0.30) in group B, and 7.06 (±0.23) in group C. So, in this study, the salivary pH was found to be lower, i.e. more acidic in tobacco smokers and tobacco chewers than in controls, and the difference was statistically significant (F = 39.47 P = 8.209E-13). Group B subjects had the lowest salivary pH because of the use of lime in smokeless form, which reacts with the bicarbonate buffering system causing loss of bicarbonate, thereby turning the saliva more acidic. As the electrolytes and ions interact with the buffering systems of saliva, the pH is altered. 
Khan et al. also found a lower salivary pH in smokers than in non-smokers,  which was consistent with the findings of the present study. Rooban et al.  had found a mean pH of 6.77 in non-chewers and in those who had the habit of chewing raw areca nut, the mean pH was lower than the non-chewers (acidic). In contrast, in 1980, Reddy et al. observed no alteration in salivary pH between chewers and non-chewers.  This difference was probably due to the amount of tobacco, lime, and few other components. Lime used in paan and betel quid was said to react with the buffering system of saliva because of the high acidic content of lime, or can cause a free radical injury thereby altering the pH. 
| Conclusion|| |
It is concluded from this experimental study on long-term tobacco users that smokeless and smoked forms of tobacco adversely affect salivary reflex, salivary secretion, and salivary pH, with the smokeless form being more harmful than the smoked form of tobacco. The effect of tobacco on long-term usage can lead to vulnerable changes in the oral mucosa and dental structures.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2]