982 D3000 new imprint Word template Vol 13, No 1 (2025) ISSN 2167-8677 (online) DOI 10.5195/d3000.2025.982 http://dentistry3000.pitt.edu Relationship between Soft Drink Consumption and Salivary pH Noah Najim Osman, Hozan Ahmed Abdulkhalik Private Prac*ce, Colorado, USA Abstract Objec7ve: To evaluate the associaFon between soI drink consumpFon, salivary pH changes, and self-reported oral health in a diverse populaFon. Material and Methods: 1,471 parFci- pants were recruited from urban and rural communiFes. A structured quesFonnaire was uF- lized to collect demographic, beverage consumpFon, oral hygiene, and perceived oral health data. Salivary pH was assessed at baseline and at mulFple Fme points (0 to 60 minutes) aIer consumpFon of five popular soI drinks (Pepsi, Coca-Cola, Seven Up, Mirinda, and Shani) us- ing a calibrated digital pH device. Data were entered into SPSS and staFsFcal analysis was performed using chi-square and the LSD tests. Results: Most parFcipants were young adults aged 26–35 years (32.5%) and were female (90.4%). Pepsi was the most frequently consumed soI drink (35.5%), and 35.4% reported daily intake. All soI drinks tested caused a staFsFcally significant decrease in salivary pH immediately following consumpFon, with minimum values achieved within 10 minutes aIer consumpFon. The minimum pH values for all the soI drink tested ranged between 5.12–5.21 and returned to near baseline values at 60 minutes. Thirty- one percent of survey respondents reported caries, and 21.2% reported staining or calcifica- Fons. Despite 94.4% of respondents reporFng brushing their teeth regularly, regular con- sumpFon of a soI drink remains high. Conclusion: There is a strong effect of soI drink con- sumpFon on salivary pH, creaFng relevant condiFons for enamel demineralizaFon and caries formaFon. High-frequency intake of acidic beverages is sFll a substanFally high-risk factor for caries, regardless of a good level of oral hygiene behavior. Public health interven- Fons for promoFng educaFonal public health strategies targeFng youth about important issues related to soI drink consumpFon should work to significantly reduce consumpFon of soI drinks and promote healthier alternaFves. Open Access Cita%on: Osman NN, et al. (2025) Rela%onship between So= Drink Consump%on and Salivary pH. Den%stry 3000. 1:a001 doi:10.5195/d3000.2025.982 Received: July 6, 2025 Accepted: July 6, 2025 Published: August 21, 2025 Copyright: ©2025 Osman NN, et al. This is an open ac- cess ar%cle licensed under a Crea%ve Commons ATribu- %on Work 4.0 United States License. Email: nawrozt1979@gmail.com Introduc)on Soft drinks have been increasingly identified as an important mediator of the effects on oral health by primarily changes to the sali- vary pH, as well as shifts in the oral microbi- ome. The soft drink, especially those contain- ing high levels of sugars and acids, can de- crease the salivary pH, causing deminerali- zation of the enamel and stimulating the growth of acidogenic bacteria such as Strep- tococcus mutans, leading to an elevated risk of dental caries, as well as gingivitis and other diseases of the oral cavity. Both the type and consumption of soft drinks, as well as other oral hygiene habits such as brushing teeth, is critical to the associated oral health risk. From a significant amount of published literature and evidence, regularly consuming sugary beverages is strongly correlated with dental caries and erosion, especially in young adults and adolescents, who are the most likely to consume high amounts of these drinks [1]. In addition, the pH of saliva is relevant for oral health. Enamel is retained, and oral mi- croorganisms are regulated in a neutral-to- slightly alkaline salivary pH. Relatedly, fre- quent and extended contact of acidic bever- ages can prolong the time that the salivary pH is below neutral, which is highly condu- cive for enamel degradation and the poten- tial shift in microbial composition (dysbiosis). Research has shown that sali- vary pH drops in a soft drink trial after con- sumption and gradually returns to baseline values in varying timeframes depending on individual salivary buffering capacity and oral hygiene [2,3]. Hot drinks (e.g., tea and coffee) can alter oral conditions as well, with noted effects that are not as substantial as an acidic beverage. While tea alone has health benefits due to polyphenols, these benefits could quickly be invalidated if sugar or any artificial sweet- ener is added. Overall, the study of both hot and soft beverages has been linked to stain- ing, erosion of dental structure, and unset- tling oral health conditions [1]. RelaFonship between SoI Drink ConsumpFon and Salivary pH Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.982 http://dentistry3000.pitt.edu 2 The current study examines a relationship between soft drink consumption, changes in salivary pH values, and oral health through an extensive survey and clinical assessment. It also looks at how demographics – age, gen- der, residence, and educational level can af- fect beverage preferences and oral health-re- lated behaviors. This study's Qindings high- light the current dietary habits of people, particularly the health impacts of soft drink consumption, emphasizing the need for pre- ventative measures, and for public health ac- tions to mitigate the risk of dental diseases attributable to soft drink consumption. Material and Methods This study aimed to investigate the relation- ship between consumption of soft drinks, changes in salivary pH, and oral health sta- tus. A questionnaire-based survey combined with clinical measurements of salivary pH assessed this relationship. Study design and subjects This cross-sectional study included 1,471 subjects. Participants were recruited from a variety of locations: Baghdad, other gover- norates, and rural areas. To obtain a wide va- riety of socio-demographic backgrounds, the study population had diversity in gender, age, educational level, and location. Partici- pation was voluntary, and all subjects gave informed consent. Survey Questionnaire A structured questionnaire was used to elicit detailed information regarding demographic data (age, gender, educational level, resi- dence), consumption of soft and hot drinks (types and frequency), oral hygiene habits (frequency and method of tooth brushing), self-reported oral health conditions (caries, gingivitis, calciQications, staining), and sys- temic health conditions of interest (diabetes, hypertension, and others). The survey also included questions regarding participants' inclination to abstain from soft and hot drinks, and what they perceived to occur the oral cavity after ingestion. Collections of samples The product to be used is a 350 ml can of soft drink (Pepsi, Cola, Seven, Mirinda) and Shani (By Baghdad Company). A sample of saliva will be placed in a urine cup or the nearest container of a similar size and shape. The soft drink can will be consumed, rinsing Qirst, then swallowing it while collecting the saliva in different periods (immediately after drinking and then after 10, 20, 30, 40, 50 and 60 minutes) for later pH measurement. Measurement of saliva pH Salivary pH was measured using a calibrated digital pH meter (ISOLAB Laborgeräte GmbH, Wertheim, Germany). Carbonation occurs, when pressurized carbon dioxide (CO₂) is infused into liquids, producing car- bonic acid and raises dissolved levels of CO₂. A typical carbonated soft drink is composed of approximately 94% water and falls be- tween the pH of 2.5 and 3.5, which therefore is an acidic drink. The carbonation, or partial pressure of the CO₂, determines the level of acidity of the beverage. Typically, soft drinks are carbonated at atmospheric pressures of about 2.5, which would generate high levels of dissolved CO₂ and a pH of about 3.7. Con- versely, atmospheric pressure levels of CO₂ in a soft drink would decrease the levels of dissolved CO₂, causing the pH to increase to- wards 5.7. Therefore, the carbonation of each beverage affects their respective acid- ity. In this clinical trial, we examined the impact of consumption of soft drinks on salivary pH. We selected 5 widely available soft drinks— Pepsi, Coca-Cola, Seven Up, Mirinda, and Shani—and conducted a salivary pH assess- ment. Salivary pH assessments were taken at baseline (i.e., prior to consumption) and af- ter consumption at 0, 10, 20, 30, 40, 50, and 60 minutes. Saliva samples were collected using sterile containers and pH measure- ments were taken immediately using the dig- ital pH meter to provide accuracy and relia- bility. Statistical Analysis The Statistical Packages for Social Sciences - SPSS (2019) program was utilized to exam- ine the effect of different factors on study pa- rameters (percentage). To compare percent- ages (0.05 and 0.01 probabilities) chi-square test of independence was used to determine signiQicance. The least signiQicant difference (LSD) test was used to make comparisons in means in this research. Results In total, 1,471 participants were recruited and surveyed as part of the study. Age de- mographics indicated that the largest age group was in the 26–35-year range (32.5%), followed by the 15–25-year age cohort (24.6%). Most participants were female (90.4%) from Baghdad (67.5%). While 35.8% had obtained a bachelor's degree, there were also many students (25.6%) as shown in Table 1. Soft Drink Consumption Patterns Pepsi was the most consumed soft drink (35.5%) followed by Coca-Cola (24.2%), Seven Up (10.8%), Mirinda (7.3%) and diet drinks (11.7%). The frequency of soft drink consumption indicated that 35.4% reported one time per day and 31.7% reported an- other frequency. Tooth brushing habits were reported by 94.4% of participants and 39.4% reported they would abstain from soft and hot drinks upon advice as seen in Table 2. Hot Drink Consumption Tea was the most common type of hot drink (50%), coffee ranked second (22.2%), and Nescafé ranked third (20.8%). When asked how many times they drank hot drinks, 40.7% reported only once a day. When asked what their preferred drink was, 30.7% pre- ferred juices, 28.3% preferred hot drinks, 25.6% preferred soft drinks as outlined in Table 3. Oral Hygiene and Perceived Oral Health When asked about the frequency of tooth brushing, 41.7% stated once a day and 40.4% stated twice a day. When asked about cleaning methods, 54.9% stated toothpaste and 42.5% stated toothpicks. About 34.1% indicated that they noticed an altered mouth sensation after consumption of soft or hot drinks, while 35.4% were unsure. In terms of oral health conditions, 58.7% rated their oral health as fair and 28.4% as good. Caries was reported by 31.6% of participants, while 21.2% reported calciQications and staining. 8.6% reported gingivitis. Most participants (77.7%) reported no chronic diseases. Effect of Soft Drinks on Salivary pH All the tested soft drinks showed a signiQi- cant reduction in salivary pH immediately af- ter consumption (P≤0.05). The drinks that are tested (Coke, Pepsi, Seven Up, Mirinda, and Shani) all showed a rapid decline to their lower levels within ten minutes (pH of 5.12 to 5.21). After ten minutes of consumption, salivary pH begins to display gradual signs of recovery over the next hour to restore sali- vary pH within range of baseline, wherein pH at 60 minutes returns to baseline slightly above 7.0. Out of all drinks, although Shani produced the greatest pH Qluctuations between base- line and at the 60-minute mark, statistical analysis between spikes in pH was also max- imized document through LSD test. Of bever- age comparisons made, Shani (7.19) and Mirinda (7.15) exhibited the greatest pH re- covery at the 60-minute observation period as documented in Table 4. Discussion The current study provides evidence regard- ing the relationship between soft drink con- sumption, salivary pH changes, and self-re- ported oral health conditions in sizeable and diverse samples. The association between RelaFonship between SoI Drink ConsumpFon and Salivary pH Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.982 http://dentistry3000.pitt.edu 3 soft drink consumption and salivary pH was not subtle; soft drink consumption resulted in a statistically signiQicant effect on salivary pH, with the greatest drop evident immedi- ately following the drink and subsequently returning to baseline levels after a period of approximately 60 minutes. The results are consistent with those exhibited in the Stephan curve; a well-established observa- tion reporting how the consumption of fer- mentable carbohydrates causes rapid de- clines in both plaque and salivary pH to lev- els that promote demineralization of enamel and caries formation [4]. The changes in pH at all three time points in this study aligns with previous Qindings by Kantovitz et al. (2010) [2], and Johansson et al. (2012) [3]. The authors noted similarly rapid changes in pH after soft drink use and equally gradual return to baseline pH related to the buffering nature of saliva. Overall, all the drinks tested in this study (Pepsi, Coca- Cola, Seven Up, Mirinda, and Shani) pro- duced signiQicant drops in pH levels, with the lowest levels occurring at approximately ten minutes post-consumption. This highlights the very high erosive potential of carbonated and acidic soft drinks, supporting existing evidence as noted in earlier studies linking high sugar beverages to enamel erosion [1] and risk for caries. The high levels of regular consumption re- ported among participants, along with lim- ited awareness of alcohol effects on oral health, raises the possibility of impaired oral health on some level for this population. While most study participants reported some level of tooth brushing, the reported prevalence of caries (31.6%) and calciQica- tions/staining (21.2%) may suggest self-re- porting did not accurately represent oral hy- giene measures, as the ability for these measures to overcome repeated acid chal- lenges from soft drink consumption may be limited. Existing studies support this notion, which show that habitual consumption of sugary and acidic beverages can outpace the natural remineralization, leading to an over- all loss of enamel [5]. Demographics of the current study sug- gested young adults (26–35 years) and stu- dents dominated the soft drink consump- tion, this aligns with global evidence which suggests younger populations report in- creased intake of sugar-sweetened bever- ages (SSBs) [6]. This is a signiQicant indicator of the need for targeted public health initia- tives, especially as 39.4% of participants said they would stop drinking soft drinks if ad- vised. Therefore, recommendations for health information or a behavioral aspect could be an impactful measure. Notably, Shani and Mirinda achieved the highest pH recovery at 60 minutes. This may be due to differences in drink composition, carbonation, or Qlavor additives that might have different effects on salivary stimulation and buffering capacity. Further studies that look at the actual acid levels and the buffer- ing capacities of various drinks would help clarify this [7]. This study primarily illustrated that many subjects reported consuming hot drinks, such as tea and coffee, every day. Despite tea having polyphenols that may have antimi- crobial effects [8], adding sugar to tea and consuming these drinks as frequently may cancel out any protective role and add to acid exposure and staining. In conclusion, these results support earlier evidence that dietary intake habits—primar- ily frequent consumption of acidic soft drinks—factor in daily eating and drinking behaviors which pose a signiQicant risk to dental health and drop salivary pH to below the critical pH for enamel demineralization [9]. As dentists and oral health professionals we should advocate for public health initia- tives which would insist on reducing SSB in- take frequency, highlighting water and un- sweetened alternatives, promoting timely tooth brushing after sugary and acidic drink consumption along with activities such as chewing gum to stimulate saliva production and counteract acid attacks [10]. The limitations of this study would be the fact that we only relied on self-reported oral health data, which may have underestimated or overestimated the actual presence of dis- ease, as well that this study did note account for actual tooth brushing behavior. Future work should consider looking at di- rect microbial shifts using microbiome se- quencing to better connect salivary pH changes with speciQic bacterial Qluctuations. Periodic studies as compared to longitudinal studies would help understand the causal ef- fects of soft drink habits and cumulative enamel loss. Conclusions In conclusion, our Qindings show that fre- quent consumption of soft drinks is sufQi- cient to lower salivary pH to levels that are conducive to enamel demineralization and dental caries. Our study complements exist- ing studies showing the popular carbonated soft drinks Pepsi, Coca-Cola Seven Up, Mirinda, and Shani elicit a rapid lowering of salivary pH with recovery occurring on aver- age within one hour which is like the Stephan Curve. The high prevalence of caries and staining in this study and the individual re- ported oral hygiene practices reQlect the inability of physical tooth-brushing alone to offset frequent acid exposure from soft drinks. The results of our study illustrate the need for a targeted public health education and public health practice aimed at behavior change with consumers, especially for those most frequent soft drink consumers (young adults and students). The good news is that there is opportunity to reduce the amount soft drink consumption, sustain positive bev- erage choices, and raise awareness of risks to dents erosion and caries. Future studies should explore the relationship of frequency soft drink consumption, salivary buffering capacity, and the oral microbiome changes within the design to inform better preven- tive strategies. These results underscore the limitations of conventional retreatment using rotary Qiles and highlight the importance of chemical support, especially when dealing with bioc- eramic sealers. The use of 20% citric acid, particularly with ultrasonic activation, emerges as a clinically viable and effective supplement to mechanical retreatment tech- niques. The study supports integrating these protocols into routine retreatment proce- dures to enhance debridement and improve clinical outcomes. References 1. Moynihan P, Kelly S. Effect on caries of restrict- ing sugars intake: systematic review to inform WHO guidelines. J Dent Res. 2014;93(1):8-18. 2. Kantovitz, K. R., Pascon, F. M., Rontani, R. M. P., Gavião, M. B. D. (2010). Caries risk assessment in schoolchildren using a reduced Cariogram model. Caries Research. 3. Johansson AK, Lingström P, Imfeld T, Birkhed D. Influence of drinking method on tooth surface pH during exposure to beverages in situ. Caries Res. 2012;38(2):156-161. 4. Stephan, R. M. (1944). Changes in hydrogen-ion concentration on tooth surfaces and in carious le- sions. Journal of the American Dental Association. 5. Zero, D. T. (2004). Sugars—The arch criminal? Caries Research. 6. Han, E., Powell, L. M. (2013). Consumption pat- terns of sugar-sweetened beverages in the United States. Journal of the Academy of Nutrition and Di- etetics. 7. Hara, A. T., Zero, D. T. (2010). The caries environ- ment: Saliva, pellicle, diet, and hard tissue ultra- structure. Dental Clinics of North America. 8. da Silva, M. A. L., et al. (2019). Polyphenols and their beneIits on oral health: A review. International Journal of Dentistry. 9. Featherstone, J. D. B. (2000). The science and practice of caries prevention. Journal of the Ameri- can Dental Association. 10. Touger-Decker, R., van Loveren, C. (2003). Sug- ars and dental caries. American Journal of Clinical Nutrition. RelaFonship between SoI Drink ConsumpFon and Salivary pH Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.982 http://dentistry3000.pitt.edu 4 Table 1. Sample studied. Chi-Square (P-value) Percentage Number of Response Questionnaire Age group (year) 164.27 (0.0001) 24.6 362 15-25 32.5 479 26-35 8.9 131 36-45 5.2 74 46-55 2.4 36 56-65 26.4 389 Undefined -- 100 1471 Total Education 271.02 (0.0001) 25.6 377 Student 35.8 526 Bachelor’s 7.6 110 Master’s 4.6 68 Doctorate 2.8 42 Others 23.6 348 Undefined -- 100 1471 Total Residence 284.93 (0.0001) 67.5 992 Baghdad 26.9 394 other governorates 1.8 19 Villages and countryside 3.8 47 Others -- 100 1471 Total Gender 8.2 119 Male RelaFonship between SoI Drink ConsumpFon and Salivary pH Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.982 http://dentistry3000.pitt.edu 5 168.55 (0.0001) 90.4 1330 Female 1.4 22 Undefined -- 100 1471 Total Table 2. Soft drink consumption. Chi-Square (P-vale) Soft drinks (N and percentage) 351.28 (0.0001) 35.5 523 Pepsi 24.2 357 Coca cola 7.3 108 Miranda 10.5 151 Seven up 10.8 159 Diet drinks 11.7 173 Others -- 100 1471 Total you drink soft drinksHow often do (N and percentage) 276.09 (0.0001) 35.4 522 once a day 9.5 140 twice a day 3.8 56 three a day 1.3 15 four a day 1.1 17 more than five a day 31.7 467 others 17.2 254 undefined -- %10 1471 Total Do you brush teethyour (N and percentage) 359.82 (0.0001) 94.4 1389 Yes 3.3 50 No 2.3 32 Undefined 100 1471 Total -- If you were asked to abstain from soft and hot drinks, would you abstain from doing so (N and percentage) 39.4 581 Yes RelaFonship between SoI Drink ConsumpFon and Salivary pH Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.982 http://dentistry3000.pitt.edu 6 291.37 (0.0001) 20.8 305 No 39.3 577 Maybe 0.5 8 Undefined 100 1471 Total Table 3. Hot drink consumption. Chi-Square (P-value) percentage number of responses Questionnaire hot drinks 189.66 (0.0001) 50 736 Tea 3.2 46 Green tea 22.2 327 Coffee 20.8 306 Nscafe 3.8 56 Others -- 100 1471 Total how often do you drink hot drinks 192.52 (0.0001) 40.7 600 Once a day 24.3 354 Twice a day 13.9 205 Three a day 4.4 65 Four a day 2.9 43 More than five a day 13.8 204 Others -- 100 1471 Total what is your favorite drink 368.09 (0.0001) 25.6 378 Soft drink 28.3 416 Hot drink 30.7 451 Juices 15.4 226 Others -- 100 1471 Total How often do you brush your teeth RelaFonship between SoI Drink ConsumpFon and Salivary pH Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.982 http://dentistry3000.pitt.edu 7 -- 279.36 (0.0001) 41.7 614 Once a day 40.4 593 Twice a day 6.7 100 Three a day 4.9 73 After every meal 6.3 91 Other -- 100 1471 Total What do you use to clean your teeth 407.61 (0.0001) 54.9 809 Toothpaste 0.6 9 Mouthwash 1.4 19 Dental floss 0.6 8 Tooth pick 42.5 626 Other 100 1471 Total Did you feel a change in your mouth after drinking soft or hot drinks -- 359.63 (0.0001) 34.1 502 Yes 28.1 414 No 35.4% 522 Maybe 2.4 33 Others 100 1471 Total What is the condition of your teeth 392.74 (0.0001) 28.4 419 Good 58.7 864 Fair 11.7 173 Poor 1.2 15 Others -- 100 1471 Total What cases do you have below 347.21 (0.0001) 31.6 465 Caries 8.6 127 Gingivitis 21.2 311 Calcifications and staining RelaFonship between SoI Drink ConsumpFon and Salivary pH Vol 13, No 1 (2025) DOI 10.5195/d3000.2025.982 http://dentistry3000.pitt.edu 8 38.6 568 Other -- 100 1471 Total ?Do you have a chronic disease 539.02 (0.0001) 2.3 34 Pressure diseases 1.0 16 Diabetes 1.2 16 Heart disease 5.2 75 Respiratory system diseases 3.6 54 Gastrointestinal diseases 77.7 1143 No 9.0 133 Other -- 100 1471 Total Table 4. Effect of soft drink and time on PH. Soft drink name pH value before after 0 min after 10 after 20 after 30 after 40 after 50 after 60 L.S.D. Pepsi 7.08 6.81 5.17 5.33 5.81 6.23 6.77 7.13 1.079 * Cola 7.09 6.77 5.15 5.28 5.79 6.15 6.71 7.12 1.164 * Seven 7.18 6.69 5.21 5.31 5.69 6.09 6.69 7.14 1.195 * Mirinda 7.19 6.83 5.16 5.25 5.83 6.18 6.80 7.15 1.085 * Shani 7.02 6.80 5.12 5.27 5.87 6.71 6.82 7.19 1.256 * L.S.D. 0.327 NS 0.308 NS 0.298 NS 0.271 NS 0.266 NS 0.502 * 0.326 NS 0.273 NS --- * (P≤0.05).