POC device for rapid oral pH determination based on a smartphone platform.

Salivary pH serves as a valuable and useful diagnostic marker for periodontal disease, as it not only plays a critical role in disease prevention but also in its development. Typically, saliva sampling is collected by draining and spitting it into collection tubes or using swabs. In this study, we have developed a Point-of-Care (POC) device for in situ determination of oral pH without the need for complex instruments, relying solely on a smartphone as the detection device. Our system utilizes a non-toxic vegetable colourimetric indicator, immobilized on a chitosan membrane located on a disposable stick, enabling direct sampling within the buccal cavity. An ad hoc designed 3D-printed attachment is used to ensure accurate positioning and alignment of the stick, as well as isolation from external lighting conditions. A custom-developed smartphone application captures and automatically processes the image of the sensing membrane, providing the salivary pH results. After optimizing the cocktail composition, the developed sensors demonstrated the capacity to determine pH within a range of 5.4 to 8.1 with a remarkable precision of 0.6%, achieving a very short analysis time of just 1 min. A stability study conducted on the sensing membranes revealed a lifetime of 50 days. To validate the performance of our analytical device, we compared its results against those obtained from a calibrated pH-meter, using a group of individuals. The device exhibited an average error of 2.4% when compared with the pH-meter results, confirming its reliability and accuracy.

Does salivary pH affect postoperative sore throat in the head-down position of general anesthesia?

BACKGROUND: Tracheal intubation sometimes causes postoperative sore throat (POST) due to laryngeal damage. However, clinical observations suggest that the environment of the oral cavity may also affect POST. OBJECTIVE: The purpose of this study was to investigate whether salivary pH in the oral cavity affects POST. METHODS: After obtaining ethical approval, informed consent was obtained from all patients. Patients who underwent surgery in the supine position were enrolled as the control group. Patients who underwent laparoscopic surgery in the head-down position were enrolled as the intervention group. Immediately before both groups of patients were anaesthetised, expelled saliva was collected, and salivary pH was measured. Immediately postoperatively, the same measurement was carried out before the patient regained consciousness. The primary outcome was the change in salivary pH. The secondary outcome was POST. In our study, POST was defined as pharyngeal and swallowing pain in the glossopharyngeal and superior laryngeal nerves. The normal distribution of pH was tested using the Shapiro-Wilk test followed by analysis using repeated-measurements and one-way analysis of variance. Statistical significance was set at p < .05. RESULTS: A total of 62 patients were enrolled, of whom two were excluded based on the exclusion criteria. Salivary pH in the intervention group was significantly lower than that in the control group. Five patients had POST in the intervention group, whereas none had POST in the control group had POST. CONCLUSION: Acidotic-shifted saliva is considered one of the causes of POST.

Impact of perinatal HIV exposure and infection on salivary properties among Nigerian children.

BACKGROUND: There is growing evidence that perinatal HIV infection and exposure affect salivary pH and flow rate in children in most parts of the world, but not against the background of caries and the African demographic. This study aimed to evaluate the impact of HIV infection as well as exposure on salivary properties and their influence upon the dental caries experience among school-aged children in Nigeria. METHOD: This cross-sectional study assessed the salivary flow rates and salivary pH of HIV infected and exposed school-aged (4-11) children receiving care at a Nigerian tertiary hospital. A total of 266 consenting participants which comprised of three groups as follows: (1) HIV Infected (HI) (n = 87), (2) HIV Exposed and Uninfected (HEU) (n = 82) and (3) HIV Unexposed and Uninfected (HUU) (n = 97) were recruited for the study. Questionnaires completed by parents/guardians were used for data collection. Three calibrated dentists performed oral examinations for dental caries. International Caries Detection and Assessment Scores (ICDAS) was used and presented as dmft/DMFT. Salivary pH was measured using MColourpHast™ pH indicator strips, while salivary flow rate was determined by collecting unstimulated whole saliva using the suction method. Data analysis relied on comparative statistics to determine the correlation between HIV exposure and infection on salivary pH and flow rates. RESULT: Across the groups, (HI, HEU, and HUU) mean pH of the HI was significantly less than that of HEU and HUU. Similarly, there was a statistically significant difference in the SFR across the three groups (p = 0.004). Other variables such as gender, age and oral hygiene status expressed by the gingival inflammatory scores had no significant influence on the pH and SFR of study participants. There was a rather unexpected positive correlation of DMFT of HI and HEU groups with increasing salivary flow rate; though, the relationship was weak and not significant. CONCLUSION: Perinatal HIV exposure and infection significantly impact salivary pH and flow rate among school-aged children in Nigeria. The findings of this study imply that HIV infection influenced the salivary pH, while HIV maternal exposure (without infection) impacted salivary flow rates when compared to the controls.

Assessment and Correlation of Salivary Ca, Mg, and pH in Smokers and Non-Smokers with Generalized Chronic Periodontitis.

Background and Objectives: Diagnostic evaluation with the aid of biomarkers has reached newer heights to assess disease activity. Salivary calcium, magnesium, and pH are one of the biochemical parameters which can be helpful in assessing the progression of periodontal disease. Smokers are at topnotch threat for having oral diseases, predominantly periodontal diseases. The aim of this study was to assess the salivary calcium, magnesium, and pH levels in smokers compared with non-smokers with chronic periodontitis. Materials and Methods: The current study was conducted on 210 individuals affected with generalized chronic periodontitis, with the age group between 25 and 55 years. Based on their smoking habit, an equal number of patients were categorized into two groups; namely, group I consisted of non-smokers and group II consisted of smokers. The clinical parameters that were measured included Plaque Index (PI), Gingival Index (GI), Probing Pocket Depth (PPD), and Clinical Attachment Loss (CAL). The biochemical variables that were evaluated in the current study included salivary calcium, magnesium, and pH using an AVL9180 electrolyte analyzer (Roche, Germany). The gathered data were analyzed with an unpaired t test was using SPSS 20.0. Results: A statistically significant higher PPD (p < 0.01), CAL (p < 0.05), and salivary calcium levels (p < 0.001) were observed in the smokers' compared with their non-smoking counterparts. Among the biochemical parameters, calcium showed a significantly (p < 0.001) higher level in smokers (5.79 ± 1.76) in contrast to non-smokers (3.87 ± 1.03). Additionally, a significant negative correlation (p < 0.05) between calcium and PPD was observed in non-smokers, whereas a non-significant inverse relation (p > 0.05) was seen in smokers. Conclusions: The present study indicates that the salivary calcium level can be a potential biochemical parameter to assess the progression of periodontal disease in smokers and non-smokers. Within the limitations of the current study, the salivary biomarkers appear to have an essential role in the identification and indication of the status of periodontal diseases.

Caries-related salivary parameters and oral microbial flora in patients with type 1 diabetes: A meta-analysis.

OBJECTIVES: This study aimed to conduct a meta-analysis by synthesising the outcomes of studies that investigated the relationship between type 1 diabetes (T1D) and salivary flow rate (SFR), salivary pH (SpH), salivary buffer capacity (SBC), streptococcus Mutans (SM), and lactobacillus (LB) counts. MATERIAL AND METHODS: The PRISMA statement guide was followed for the meta-analysis. Electronic databases were searched, and study selection and data collection processes were performed. The risks of bias in individual studies and across studies were assessed. Mean differences (MD) and Odds Ratio (OR) were used to measure the effect estimates in the comparisons. RESULTS: 29 studies were included in the qualitative and quantitative syntheses. Significantly higher SFR (MD = -0.22, CI: -0.26, -0.18; p < 0.001) and SpH (MD = -0.59, CI: -0.81, -0.36; p < 0.001) were observed in the healthy individuals than T1D individuals. No significant difference was observed among groups in terms of SBC (MD = 0.10, CI: -0.46,0.66; p = 0.73). An increased odds ratio of SM counts were observed regarding the T1D (OR = 3.09, 95% CI: 1.16, 8.20; p = 0.02). No association was found between LB counts and T1D (OR = 2.15, 95% CI: 0.38, 11.98; p = 0.38). CONCLUSIONS: Subjects with T1D have a significantly lesser SFR and SpH than healthy individuals. But no significant difference is available in terms of SBC. Lower SM counts were observed in individuals with T1D, while no association was observed regarding LB counts. The tendency to dental caries is more likely in subjects with T1D due to lower SFR, SpH, and higher SM.

Association between asthma and caries-related salivary factors: a meta-analysis.

OBJECTIVES: This meta-analysis aimed to examine the comprehensive conclusive evidence of association between asthma and caries-related salivary factors including salivary pH (SpH), salivary flow rate (SFR), salivary buffer capacity (SBC), and other salivary components. METHODS: Electronic databases (Web of Science, PubMed, Scopus, Cochrane Library, and Open Gray databases) were searched for relevant studies. After screening, studies were selected and data were collected from each study. The risk of bias in individual studies and across studies was evaluated. Mean differences (MD) were used to measure the effect estimates in the comparisons of SFR, SpH, SBC, and other salivary components. Additional analyses, namely sensitivity, subgroup, and Grades of Recommendation, Assessment, Development, and Evaluation analyses, were also conducted. RESULTS: Eighteen and fourteen studies were included in the qualitative and quantitative synthesis, respectively. Significantly higher SFR (MD = -0.3, 95% CI [-0.39, -0.2], p < 0.001) and SpH (MD = -0.25, 95% CI [-0.45, -0.05], p = 0.01) were found in the reference group compared to the group with asthma. A significant difference in SBC was found only for unstimulated saliva (MD = -0.20, 95% CI [-0.24, -0.15], p < 0.001). No significant associations were found between asthma and other salivary components (p > 0.05). CONCLUSIONS: Notwithstanding the limitations of this study, the evidence showed that SFR whether stimulated or unstimulated was significantly reduced in asthma patients. SBC and SpH were significantly reduced in asthma patients only when saliva was unstimulated. No evidence was found regarding the association between asthma and other salivary components.

Memory decline in older individuals predicts an objective indicator of oral health: findings from the Sydney Memory and Ageing Study.

BACKGROUND: Growing evidence suggests that there is an association between poor oral health and cognitive function in late adulthood. However, most studies to date have relied on cross-sectional research methods that do not permit inferences about the temporality of any association. Moreover, the few longitudinal studies that do exist have typically relied on small samples and quite limited cognitive or oral health assessments. The aim of the present study was therefore designed to provide the first direct evaluation of whether cognitive function is predictive of poor oral health in older adults. METHODS: This longitudinal research included data from 339 participants aged 70 years or older from The Sydney Memory and Ageing Study (MAS), a large cohort of healthy community-dwelling older adults. Cognitive function was assessed using a battery of tests at baseline (Wave 1) in 2005 and six years later (Wave 4) in 2011. In 2015 (Wave 6), participants were assessed for oral health using the Oral Health Assessment Tool (OHAT), number of functional occluding pairs of natural teeth and sublingual resting saliva pH (SRSpH). Ordinal least squares regression analysis was used to model the effect of cognitive function on total OHAT score, and binomial logistic regression used for SRSpH and occluding pairs of functional teeth. RESULTS: Two models were tested. In the partially adjusted model, age, gender and years of education were included. The fully adjusted model additionally included medical conditions, general health, depression, smoking, alcohol consumption, functionality, and dental care utilization. The key finding to emerge was that a six-year change in memory (from Wave 1 to Wave 4) was associated with lower sublingual resting saliva pH at Wave 6 in partially (Odds Ratio (OR) = 0.65) and fully adjusted model (OR = 0.63). CONCLUSIONS: This longitudinal study provides further evidence that a relationship between cognitive function and oral health exists, and also points to this relationship potentially being bi-directional, as previous evidence suggests. The findings from the study also suggest that older adults who present with greater than normal memory decline at an earlier point in life were more likely to experience poor oral health when this was evaluated at a later time-point, four years later.

LIMITED EVIDENCE SUGGESTS THAT END STAGE KIDNEY DISEASE AND HEMODIALYSIS MAY IMPACT SALIVARY FLOW RATE AND COMPOSITION.

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION: Rodrigues RP, Vidigal MT, Vieira WA, Nascimento GG, Sabino-Silva R, Blumenberg C, Siqueira MF, Siqueira WL, Paranhos LR. Salivary changes in chronic kidney disease and in patients undergoing hemodialysis: a systematic review and meta-analysis. Journal of Nephrology. 2022 Mar 2:1-29. SOURCE OF FUNDING: The work has been partially funded by CAPES-Finance Code 001. The authors have also acknowledged The Brazilian National Council for Scientific and Technological Development (CNPq) and Minas Gerais State Agency for Research and Development, Brazil (FAPEMIG) for the support. TYPE OF STUDY/DESIGN: Systematic review with meta-analysis of data.

Differences in perceived intra-oral dryness in various dry-mouth patients as determined using the Regional Oral Dryness Inventory.

OBJECTIVES: Recently, it was shown that the Regional Oral Dryness Inventory (RODI) could determine differences in dry-mouth perception at different intra-oral locations. The main aim of this study was to determine whether the RODI might help to discriminate between various causes of oral dryness in dry-mouth patients. The second aim was to ascertain whether the RODI could become an additional diagnostic tool in dry-mouth patients. MATERIALS AND METHODS: Data were collected retrospectively from patients who visited a specialized saliva clinic. Salivary flow rates, Xerostomia Inventory scores, and RODI scores were extracted from the medical records. Patients were stratified into subgroups according to their health status. RESULTS: Five hundred twenty-eight patients participated in this study (mean age of 59.6 ± 16.0 years; 68.4% female). Specific patient groups differed with regard to the region of the mouth they experienced as the most and least dry. The posterior palate was the area perceived as most dry by controls and Sjögren patients. In patients using limited or multiple medications, it was the anterior tongue. RODI scores also differed significantly among dry-mouth patient groups: whereas controls and patients using limited medication had the lowest RODI scores and experienced less intra-oral dryness, Sjögren patients had the highest RODI scores. CONCLUSION: Our use of the RODI questionnaire showed that perceived intra-oral dryness differed between the various dry-mouth patients. CLINICAL RELEVANCE: The RODI can be a valuable clinical diagnostic tool in dry-mouth diagnostics, in which it can be used to discriminate between the various causes of oral dryness in patients.

Physiological and Immunological Changes Associated with Oral Microbiota When Using a Thermoplastic Retainer.

Background: The study examined the oral microbiota, physiological and immunological changes in patients using thermoplastic retainers during three months of use. Methods: The study included several steps. Firstly, 10 swabs were collected from the buccal and palatal surfaces of the teeth of the patients, approximately 2 mL of saliva was collected from the same patients and 2 mL of saliva was collected from 10 healthy people to measure the pH and secretory IgA level. This was followed by the isolation and identfication of the bacterial isolates in the patient samples. Then, isolate susceptibility toward chlorhexidine (CHX) and their adhesion ability to thermoplastic retainer surfaces was measured. In addition to that the study estimated the numbers of Lactobacillus and Streptooccus mutans colonies during three months and finally, a comparsion of pH acidity and IgA level between the patients and healthy people was performed. The results showed the predominant bacteria during the three months were Lactobacillus spp. and Streptococcus spp. followed by different rates of other bacteria. Raoultella ornithinolytica showed more resistance to CHX while Lactobacillus spp. showed more sensitivity. Streptococcus mutans colony levels were higher than Lactobacillus spp. colonies during the three months, also S. mutans had the highest value in adherence to retainer thermoplastic. Finally, pH acidity showed a highly significant difference (p ≤ 0.05) in the third month, like IgA levels (p ≤ 0.05). Conclusions: According to the results obtained from the current study, the researchers noted that the thermoplastic retainers helped change the oral cavity environment.

The association between changes of gustatory function and changes of salivary parameters: A pilot study.

OBJECTIVE: The aim of the pilot study was to explore which of the salivary parameters best reflects improvement or deterioration of taste function. METHODS: A total of 14 patients were included. Taste ability was measured using taste strips and patients rated their symptom strength using visual analogue scales. Salivary parameters (flow rate, total proteins, proteolysis, catalase, total anti-oxidative capacity [TAC], carbonic anhydrase VI [caVI], and pH) were determined and the Beck Depression Inventory (BDI) was administered. All these parameters were measured twice with a one-year interval to acquire the changes of data. RESULTS: Patients with decreased taste function exhibited a decrease in salivary proteolysis and caVI, and an increase in salivary total protein. Patients with increased taste function also showed an increase in salivary total protein. Δ Salivary flow rate was negatively correlated with Δ taste strip scores. Δ Salivary pH was significantly lower in patients with increased taste function compared to patients with decreased taste function. Δ BDI was positively correlated with both Δ symptoms ratings. Across all patients, symptom ratings decreased while salivary total protein increased; salivary flow rate, proteolysis and caVI decreased significantly compared with baseline. CONCLUSIONS: The present longitudinal results suggest that changes of both taste function and taste complaints were accompanied by changes in salivary parameters, indicating that salivary parameters have the potential to be useful in the diagnosis of patients with qualitative taste disorders.

Salivary pH changes under the effect of stainless steel versus elastomeric ligatures in fixed orthodontic patients: a single-center, randomized controlled clinical trial.

BACKGROUND: Fluctuations in pH of saliva during a prolonged treatment course influences the enamel demineralization progress, which is one of the complications of fixed orthodontic treatment. This randomized clinical trial aimed to evaluate and compare the short-term effects of stainless steel (SS) versus elastomeric (EM) ligatures on salivary pH in patients scheduled for fixed orthodontic treatment. METHODS: Seventy participants were enrolled in the study (54 female, 16 male) aged 19-36 years who met specific inclusion criteria. They were randomly selected and allocated into two equal groups through computer-generated randomization. All patients received fixed orthodontic treatment using conventional orthodontic brackets. Two commonly used archwire ligature methods were used: SS and EMs. An unstimulated (resting) salivary sample was collected before tying of the ligatures at T0 (baseline), 2 weeks, 6 (weeks), and 12 (weeks). Salivary pH was measured using a digital pH meter. The level of significance was set at p value < 0.05. RESULTS: The salivary pH level was stable between T0 and T1 (6.72 ± 0.14), then significantly and progressively increased from T1 to T2 (6.78 ± 0.13) and from T2 to T3 (6.81 ± 0.14) with (p < 0.05) in the SS group. In the EM group, the salivary pH level was significantly decreased in all follow-up periods; T0 (6.77 ± 0.16), T1 (6.72 ± 0.14), T2 (6.67 ± 0.13) and T3 (6.64 ± 0.13). CONCLUSION: The EM ligatures showed a significant decrease in salivary pH to an unfavorable level, which increased the risk of enamel demineralization. Therefore, EMs as ligature material is preferably should not be recommended in patients with high caries index or inadequate oral hygiene. Trial registration ANZCTR.org. (ACTRN12618001647224) http://www.anzctr.org.au/ACTRN12618001647224.aspx . Registration Date: 5/10/2018, "Retrospectively registered".

Dimethylaminododecyl methacrylate inhibits Candida albicans and oropharyngeal candidiasis in a pH-dependent manner.

The prevalence of stomatitis, especially that caused by Candida albicans, has highlighted the need for new antifungal agents. We previously found that a type of quaternary ammonium salts, dimethylaminododecyl methacrylate (DMADDM), incorporated in dental materials inhibited the growth and hyphal development of C. albicans. However, how the quaternary ammonium salts inhibited the fungal pathogens and whether the oral condition, such as salivary pH variation under different diseases, can affect the antimicrobial capacity of quaternary ammonium salts is unknown. This study evaluated the antifungal effects of DMADDM at different pH in vitro and in vivo. A pH-dependent antifungal effect of DMADDM was observed in planktonic and biofilm growth. DMADDM enhanced antifungal activity at alkaline pH. Two pH-regulated genes (PHR1/PHR2) of C. albicans were correlated with the pH-dependent antifungal effects of DMADDM. The PHR1/PHR2 genes and pH values regulated the zeta potential of C. albicans, which then influenced the binding between C. albicans cells and DMADDM. The pH-dependent antifungal activity of DMADDM was then substantiated in a murine oropharyngeal candidiasis model. We directly demonstrated that the antifungal abilities of quaternary ammonium salts relied on the cell zeta potential which affected the binding between fungal cells and quaternary ammonium salts. These findings suggest a new antifungal mechanism of quaternary ammonium under different pH and that DMADDM can be a potential antifungal agent applied in dental materials and stomatitis therapy.Key Points • DMADDM has stronger antifungal activity in alkaline than in acidic pH conditions. • The pH values and pH-regulated genes can affect the zeta potential of fungal cells. • Zeta potential of fungal cells directly affect the binding between DMADDM and cells. Graphical abstract Schematic diagram of the antifungal activities of DMADDM at different pH values.

Investigation of carbonic anhydrase 6 gene polymorphism rs2274327 in relation to the oral health status and salivary composition in type 2 diabetic patients.

OBJECTIVE: The aim of the present study was to investigate the oral manifestations and salivary composition in type 2 diabetics with periodontitis and to evaluate their association with CA6 gene polymorphism rs2274327. METHODS: Oral examination was performed by a single periodontist for 300 type 2 diabetics. Whole unstimulated saliva and blood were collected. The salivary pH, buffer capacity and flow rate were later measured. Immunoglobulin A and electrolytes were assessed using an autoanalyzer. CA6 gene polymorphism rs2274327 was screened by PCR-RFLP assay. The statistical analysis was performed using the SPSS 20.0 version. RESULTS: The salivary pH, buffer capacity and flow rate were significantly lower in the patients carrying TT genotype compared to CC and CT genotype carriers (p < .05). Furthermore, the DMFT index, OHI-s, PI, PPD and CAL were significantly higher in the subjects with TT genotype (p < .05). Carrying at least one T allele seemed to increase the risk of dental caries (OR = 2.59, p < .001), xerostomia (OR = 2.11, p=.003) and taste impairment (OR = 1.97, p < .05). CONCLUSION: CA6 gene polymorphism rs2274327 seemed to increase the risk of developing, dental caries, periodontitis, xerostomia and taste impairment in type 2 diabetics.

Estimation of Proinflammatory Factors in the Saliva of Adult Patients with Cystic Fibrosis and Dental Caries.

Introduction: The available literature lacks data regarding the levels of resistin, lysozyme, lactoferrin, α-amylase activity, pH, and saliva buffer capacity, as well as oral health and hygiene in the group of adult patients with cystic fibrosis (CF). The aim of the research was to assess the selected saliva parameters in patients diagnosed with cystic fibrosis. Materials and methods: Examined group was composed of 40 patients diagnosed with CF, while the control group of 40 healthy individuals. Both groups underwent the same scheme of the assessment (DMT index, salivary pH, buffer capacity, analysis of total sialic acid, total protein estimation, lysozyme levels estimation, lactofferin levels measurement, α-amylase activity, estimation of the levels of resistin and TNF-α). Results: In the examined group, there were higher values of decayed teeth as well as values of sialic acid, total protein, lactoferrin, α-amylase, and TNF-α. However, mean lysozyme, and resistin levels, as well as pH and buffer capacity of the saliva, were lower. Conclusions: New diagnostic methods, including the evaluation of selected salivary biochemical parameters, may indicate the existence of factors predisposing to severe tooth decay in the study group. Appropriate preventive treatment to combat dental caries in adult patients with CF will significantly improve their comfort and life expectancy.

Sustaining elevated levels of nitrite in the oral cavity through consumption of nitrate-rich beetroot juice in young healthy adults reduces salivary pH.

BACKGROUND: Dietary inorganic nitrate (NO3-) and its reduced forms nitrite (NO2-) and nitric oxide (NO), respectively, are of critical importance for host defense in the oral cavity. High concentrations of salivary nitrate are linked to a lower prevalence of caries due to growth inhibition of cariogenic bacteria. OBJECTIVE: In-vitro studies suggest that the formation of antimicrobial NO results in an increase of the pH preventing erosion of tooth enamel. The purpose of this study was to prove this effect in-vivo. METHODS: In a randomized clinical study with 46 subjects we investigated whether NO3- rich beetroot juice exhibits a protective effect against caries by an increase of salivary pH. RESULTS: Our results show that, in comparison to a placebo group, consumption of beetroot juice that contains 4000 mg/L NO3- results in elevated levels of salivary NO2-, nitrite NO3-, and NO. Furthermore, we determined an increase of the mean pH of saliva from 7.0 to 7.5, confirming the anti-cariogenic effect of the used NO3--rich beetroot juice. CONCLUSIONS: Taken together, we have found that NO3--rich beetroot juice holds potential effects against dental caries by preventing acidification of human saliva. TRIAL REGISTRATION: C-87-15 (Ethics Commissions of Upper Austria).

Intraoral pH and temperature during sleep with and without mouth breathing.

To measure and compare the intraoral pH and temperature of individuals during sleep with and without mouth breathing. Ten healthy participants [mean age = 25·8 (± 4·3)] wore a custom-made appliance fitted with a pH probe and thermocouple for two sets of 48 h. Continuous pH and temperature measurements were taken from the palatal aspect of the upper central incisors. To simulate mouth breathing during sleep, participants wore a nose clip for two nights of the four, with the first group (n = 5) wearing the nose clip during the first night and the rest (n = 5) wearing the nose clip during the second night of sleep to balance any potential bias from the wearing sequence. Both qualitative and quantitative analyses were conducted. The mean intraoral pH during daytime was 7·3 (± 0·4) and during sleep was 7·0 (± 0·5). The mean intraoral pH during sleep with mouth breathing was 6·6 (± 0·5), which was statistically significant compared with the normal sleep condition (P < 0·01). The intraoral pH decreased slowly over the hours of sleep in all participants. When sleeping with forced mouth breathing, intraoral pH showed a greater fall over a longer period of time. The mean intraoral temperature was 33·1 °C (± 5·2) during daytime and 33·3 °C (± 6·1) during sleep, with no statistical significance between sleep with and without mouth breathing (P > 0·05). The results suggest that mouth breathing during sleep is related to a decrease in intraoral pH compared with normal breathing during sleep, and this has been proposed as a causal factor for dental erosion and caries.

Effect of dental care programme and fluoridation in the prevention of dental caries in asthmatic children.

OBJECTIVE: To investigate the effect of a regular dental care programme on the dental health of asthmatic children. METHODS: This prospective, controlled study was conducted at Dokuz Eylul University, Izmir, Turkey, between 2012 and 2014, and comprised asthmatic and non-asthmatic children between 4 and 16 years of age who used inhaler corticosteroid treatment for at least 1 year. Patients were examined for dental caries, gingival index, salivary flow rate, and salivary pH values at baseline, 6 months, and at the end of the first year. Demographic features and tooth-brushing habits of the asthmatic and non-asthmatic children were also analysed. SPSS 20 was used for data analysis. RESULTS: Of the 102 patients, there were 51(50%) each in asthmatic and non-asthmatic groups. Besides, 38(70.6%) participants were boys and 15(29.4%) were girls in the first group compared to 30(58.8%) boys and 21(41.2%) girls in the second group. The mean age was 11.16±3.10 years and 10.33±2.62 years, respectively, in the two groups. The number of asthmatic patients was 45(88.2%) in visit 2 and 37(72.5%) in visit 3, whereas the number of participants for the control group was 41(80.4%) in visit 2 and 36(70.4%) in visit 3. During the first visit, mean values for salivary pH and flow rate were 7.135 0.15 and 3.878 0.71 mL/min among asthma patients, and 7.158 0.14 and 4.684 0.50 among controls. In the first visit, the rate of gingivitis was 31(60.8%) in asthmatic children and 12(23.5%) in the control group. During the third visit, the rate was 4(11.1%) and 5(13.5%) among the two groups, respectively. CONCLUSIONS: Decreased salivary flow rates associated with the drugs used by asthmatic patients caused an increase in the rate of dental caries and gingival disorders.

Continuous measurement of intra-oral pH and temperature: development, validation of an appliance and a pilot study.

To describe a novel approach for continuous measurement of intra-oral pH and temperature in individuals carrying out normal daily activities over 24 h. We designed, validated and constructed a custom-made appliance fitted with a pH probe and a thermocouple. Six subjects wore the appliance over a 24-h period for two non-consecutive days, while the intra-oral pH and temperature were measured continuously and recorded. Intra-oral pH and temperature were very similar across different recording days, the difference being not statistically significant (P ≥ 0.14). There was a noticeable difference in the pattern of variation of pH between day and night. During the day, the mean pH was 7.3 (±0.4) and dropped markedly only after consumption of acidic food and drinks. The intra-oral pH decreased slowly during sleep with an average pH of 6.6 (±0.4) being recorded. The difference between day and night was statistically significant (P = 0.002). The mean intra-oral temperature was 33.9 °C (±0.9) during daytime and 35·9 °C (±0·5) during sleep (P = 0.013) with minor fluctuations occurring over 24 h. The continuous and simultaneous intra-oral pH and temperature measurement system described in this report is reliable, easy to construct, able to measure variables over a sustained period and may serve as a future diagnostic tool in a number of applications.

Oral manifestations in gastroesophageal reflux disease.

Many systemic diseases exert their influence on oral health. Among these, gastroesophageal reflux disease (GERD) is the most common. In this study, 100 patients who were previously diagnosed with GERD were examined following a 12-hour fast and evaluated in terms of the severity (grade) of the disease as well as any oral, dental, and/or salivary pH changes. Results found 11 patients with tooth erosion. These patients were older, and their average mean duration of GERD was longer in comparison to those without erosion. There was an inverse relationship between salivary pH and the GERD duration and grade of severity. As the GERD grade increased, the severity of tooth erosion increased. Patients with erosion also exhibited oral mucosal changes. Thus severe, long-term GERD was found to be potentially detrimental to oral soft tissues, dental structures, and salivary pH, whereas milder forms of the disease did not necessarily cause dental side effects.