Clinical characteristics and salivary biomarkers of burning mouth syndrome.

OBJECTIVES: To investigate the clinical characteristics and salivary biomarkers in each type of burning mouth syndrome (BMS) patients. MATERIALS AND METHODS: Ninety-eight postmenopausal female patients with BMS were included. Fifty and 21 patients were assigned to the primary and secondary groups, respectively. Twenty-seven patients with both primary and secondary characteristics were assigned to the intermediate group. Comprehensive clinical characteristics and salivary biomarkers were analyzed. RESULTS: Significant differences in age, proportion of hyposalivator patients based on unstimulated whole saliva (UWS), symptom distribution, severties of burning sensation and effect of oral complaints in daily life (Eff-life), and positive symptom distress index (PSDI) were observed among the three groups. The primary group had significant higher UWS flow rate, fewer UWS hyposalivator proportions, and lesser severity of Eff-life than the secondary group. The intermediate group had significantly greater intensities of burning sensation and Eff-life and higher PSDI score than did the primary group. The primary group had significantly higher cortisol and dehydroepiandrosterone (DHEA) levels in stimulated whole saliva than did the secondary group. CONCLUSIONS: This study's findings show that clinical characteristics differentiate each BMS type. Cortisol and DHEA levels are potential salivary biomarkers for discriminating between the primary and secondary types of BMS.

The teaching of geriatric dentistry in South Korean dental schools.

OBJECTIVE: The purpose of this study was to investigate the curriculum of geriatric dentistry for undergraduates in Korean dental schools. BACKGROUND: For development purposes, it was necessary to compare geriatric dentistry education programmes in South Korea to programmes in the United States and Europe. METHODS: The most recent curriculum and related information on geriatric dentistry at the undergraduate level in all 11 dental schools in South Korea were collected by both official letter and e-mail. A symposium for gathering expert opinions to improve geriatric dentistry education in South Korea was also held. The collected data were analysed, and the expert opinions at the symposium were summarised. RESULTS: Six of 11 schools had a didactic course as compulsory and three schools as elective. The course was usually conducted as a form of integrated lectures, and the level of standardisation of lecture content was very low. There were no topics for older people who cannot access dental clinics due to functional frailty or disability. No dental school-affiliated hospitals had an independent department for geriatric dentistry. No schools provided clinical teaching for geriatric dentistry. There were no outreach programmes for geriatric dentistry. CONCLUSIONS: The educational curriculum for geriatric dentistry in South Korea was insufficient to cope with social and demographic changes. Curriculum content should include clinical practice education and needs to be focused on frail and dependent older adult patients. An essential educational curriculum and core competency for geriatric dentistry should be prepared.

Changes in the lesion surface suggesting transformation of oral potentially malignant disorders to malignancy - a report of eight cases.

BACKGROUND: In the case of oral potentially malignant disorders (OPMD), the possibility of malignant transformation of the lesion necessitates a decision on the need for an additional biopsy at each visit. Among many clinical characteristics, change on the lesion surface is one of the important factors that determine the need for additional biopsy at each visit. The purpose of the study was to provide information on the characteristics of lesions related to malignant transformation during the follow-up period of OPMD. METHODS: Eight patients (four men and four women) with OPMD that transformed into malignancy during long-term follow-up were included and their mean age was 65.8 ± 12.4 years. Clinical information and histopathological diagnosis were investigated at the initial visit and during the long-term follow-up period. The focus was on information on changes on the lesion surface at the time the lesion was confirmed to be malignant. The period from initial diagnosis to dysplasia and from dysplasia to malignancy was also investigated. RESULTS: The OPMD diagnoses were oral lichen planus or oral lichenoid lesions (n = 2), oral leukoplakia (n = 5), and hyperplastic candidiasis (n = 1). During the follow-up period of the lesions, when dysplasia was obtained by additional biopsy, changes in the lesions consisted of an increase in the size of the white or red area. The lesion surface of the OPMD showed verrucous, papillary, exophytic, corrugated, and ulcerative changes at the time of malignancy diagnosis. The period for the initial lesion to become dysplasia, from dysplasia to malignancy, and from the initial lesion to malignancy was very variable. CONCLUSIONS: Attention should be paid to verrucous, papillary, exophytic, corrugated, and ulcerative changes on the lesion surface of OPMD. Considering that the period for OPMD to become malignant is highly variable, a longer follow-up of the lesion is necessary.

Treatment outcomes and related clinical characteristics in patients with burning mouth syndrome.

OBJECTIVES: To evaluate the treatment outcomes of medication therapies in patients with burning mouth syndrome (BMS) and to identify the clinical characteristics that may affect the efficacy of prescribed medications. METHODS: This is a retrospective study of 769 patients with oral burning sensations. Of these patients, 420 patients diagnosed as the primary BMS received an "Initial Approach" that involved a detailed explanation about its etiopathophysiology, self-care instruction, and use of an oral lubricant. Neuropathic medications were prescribed for 277 patients who did not respond to the initial approach. Clinical characteristics, prescribed medications, and changes in intensity of oral symptoms were reviewed. RESULTS: Clonazepam was administered as the first-line medication. Alpha-lipoic acid (ALA), gabapentin, and nortriptyline were commonly administered in combination with clonazepam. More than two-thirds of the patients reported a marked improvement in oral symptoms after treatments with combination of neuropathic medications and ALA. The efficacies of the initial approach and clonazepam had significant positive associations with the initial intensity of oral symptoms and significant negative associations with depression. CONCLUSIONS: Clonazepam therapy in combination with appropriate medications was effective for managing patients with BMS. The initial intensity of oral symptoms and psychological status were significantly associated with treatment outcomes.

Oral health-related quality of life and associated factors in patients with burning mouth syndrome.

OBJECTIVE: The purpose of this study was to assess oral health-related quality of life (OHRQoL) in patients with burning mouth syndrome (BMS) and to identify clinical factors associated with OHRQoL. METHODS: Fifty-seven patients with BMS (56.4 ± 10.7 years) participated in the study. Patients underwent oral examination, laboratory tests, psychological evaluation, measurement of salivary flow rates and evaluation of clinical characteristics using a BMS questionnaire. The OHRQoL of patients was assessed using the Oral Health Impact Profile-14 (OHIP-14). RESULTS: The OHIP-14 score for patients with BMS was 38.6 ± 12.8. Patients had higher scores for the psychological discomfort and physical pain dimensions of the OHIP-14. The intensity of taste disturbance or xerostomia symptoms (ß = 0.464, P < .001), worry about symptoms (ß = 0.307, P = .020), and results of psychological evaluation (ß = 0.311, P = .026) were significantly associated with OHIP-14 score. Multiple linear regression showed that the intensity of taste disturbance or xerostomia symptoms was significantly associated with decreased OHRQoL (ß = 0.637, P = .026). CONCLUSIONS: This study suggests that severity of taste disturbance or xerostomia is an important factor that influences OHRQoL in patients with BMS.

Developing a clinical presentation dental education model and a pilot test.

INTRODUCTION: Accurate clinical decision-making of dentists should be based on their knowledge and experience. In the past 10 years, interest in competency-based dentistry education has rapidly increased, but there has been little attention paid to methods of improving dental education competency. The purpose of this study was to develop a clinical presentation education model that provides opportunities for students to practice problem-solving from the moment they greet the patient so that students can obtain the practical experience of competency-based education and the effectiveness of this model can be confirmed through pilot test. METHODS: This article is divided two parts: First, developing the clinical presentation dental education model (CPDEM) and Second, a pilot study adopted CPDEM. To confirm the effectiveness of this model, the students' satisfaction, their perception of self-achievement were analysed. RESULTS: Clinical presentation dental education model has been developed to provide practice-related education experience and provide linkage between basic science and clinical science. The result of applying this education model to 10 students as a pilot test was shown an overall high satisfaction level. In addition, self-achievement students' reported of all intended competencies was higher than for non-participating students of this model. CONCLUSIONS: This study focuses on practical education centring on clinical presentation. This model could get a meaningful and realistic experiences through the practice using clinical presentation of patients, use their metacognition for organizing and memorizing the patient's case by using concept map. It can be used as a future instructional method to enhance students' competency.

Oral health-related quality of life and associated factors in patients with xerostomia.

OBJECTIVE: This study aimed to investigate clinical and demographic factors associated with oral health-related quality of life (OHRQoL) in patients with xerostomia. METHODS: Forty-one patients (55.2 ± 13.8 years) with xerostomia as a chief complaint participated in the study. Comprehensive information about clinical and demographic characteristics of the patients with xerostomia, xerostomia-related symptoms and behaviours, and xerostomia-associated complaints was investigated using a xerostomia questionnaire. Flow rates of unstimulated and stimulated whole saliva were measured. The Oral Health Impact Profile-14 (OHIP-14) score was used to assess the OHRQoL of patients. The relationships between various factors and the OHIP-14 score were assessed by simple and multiple linear regression analyses. RESULTS: The OHIP-14 score of patients with xerostomia was high (44.3 ± 13.2). Characteristics of the patients with xerostomia associated with high OHIP-14 score were the intensity of xerostomia-related symptoms, frequency of xerostomia-related behaviours and the presence of speaking difficulty. Results from multiple linear regressions found that self-reported amount of saliva in usual, everyday life (ß = 0.622, p = 0.012) and the presence of a speaking difficulty (ß = 0.348, p = 0.014) had significant adversely affected the OHRQoL in patients with xerostomia. CONCLUSIONS: Subjective perceptions of the amount of saliva in the mouth and the experience of speaking difficulty affected the OHRQoL in patients with xerostomia.

Relationships between gustatory function tests.

OBJECTIVES: To investigate the relationships among four different gustatory function tests in healthy young adults: electrogustometry (EGM), filter paper disk (FPD), whole-mouth, and taste strip methods. The relationships of the results of gustatory function tests with salivary flow rate were also investigated. METHODS: Sixty healthy young adults (30 men, 26.9 ± 4.7 years; 30 women, 25.7 ± 4.6 years) who did not have disorders or conditions related with gustatory function were included. Four different gustatory function tests using the EGM, FPD, whole-mouth, and taste strip methods were performed in each participant with 2- to 3-day intervals between tests. The flow rates of unstimulated and stimulated whole saliva were measured. RESULTS: There were no significant differences between sexes in all the examined gustatory function tests. The levels of correlations between the gustatory function tests were low. The EGM threshold correlated with the taste score of the FPD method in the chorda tympani nerve area. Different chemical gustatory function tests did not correlate significantly in any of the four taste qualities. Salivary flow rates did not correlate with taste perception. CONCLUSIONS: The correlations between gustatory function tests were weak. A significant correlation was found between the results of EGM and FPD methods in the chorda tympani nerve area.

Viscosities of mixtures of hyaluronic acids with different molecular weights and their effects on enzymatic activities of lysozyme and peroxidase.

OBJECTIVES: To investigate the viscosity values of mixtures of hyaluronic acids with different molecular weights and the effects of these mixtures on the enzymatic activities of lysozyme and peroxidase. MATERIALS AND METHODS: Mixtures of high molecular weight (1 or 2 MDa) and low molecular weight (10 or 100 kDa) hyaluronic acids at different concentrations were used for viscosity measurements. Hyaluronic acid mixtures showing viscosity values similar to those of human whole saliva were used for enzyme experiments in solution and on hydroxyapatite surface. Hen egg-white lysozyme, bovine lactoperoxidase, and human whole saliva were used as enzyme sources. Lysozyme activity was measured by hydrolysis of fluorescein-labeled Micrococcus lysodeikticus. Peroxidase activity was measured by oxidation of fluorogenic 2',7'-dichlorofluorescein to fluorescing 2',7'-dichlorofluorescein. RESULTS: The mixtures of 1 MDa (0.5 mg/mL) or 2 MDa (0.2 mg/mL) hyaluronic acid with 10 kDa (2.0 mg/mL) or 100 kDa (0.1 mg/mL) hyaluronic acid had viscosity values similar to those of human whole saliva at shear rates, reflecting normal oral functions. Compared with single molecular weight hyaluronic acids, these mixtures showed viscosity values more similar to those of human whole saliva. The mixtures inhibited lysozyme and peroxidase activities on the hydroxyapatite surfaces; however, the degree of inhibition did not differ from that of hyaluronic acid of 1 or 2 MDa only. CONCLUSIONS: Compared with single molecular weight hyaluronic acids, hyaluronic acid mixtures showed viscosity values more similar to those of human whole saliva, without additional inhibitory effects on lysozyme and peroxidase activities. CLINICAL RELEVANCE: Hyaluronic acid mixtures offer distinct advantages for the development of saliva substitutes.

Development of an Oral and Maxillofacial Frailty Index: A preliminary study.

OBJECTIVE: The purpose of this study is to develop an index to measure oral and maxillofacial frailty in older adults as an acceptable screening tool. METHODS: Three hundred adults (aged ≥ 50 years) participated in this study by telephone interview. Ten candidate items for the Oral and Maxillofacial Frailty Index (OMFI) and 20 matched detailed items for oral and maxillofacial functions were asked. Information about sociodemographic and oral health-related variables was also obtained. The test-retest reliability of the 10 candidate items was determined. Correlations of the 10 candidate items with the 20 detailed items or sociodemographic and oral health-related variables were analysed to test the validity of the candidate items. To suggest optimal items for the OMFI, five different models with different numbers of items were constructed and evaluated based on their associations with main variables. RESULTS: The overall internal consistency of the 10 candidate items was .704, and the Cronbach's alpha value of each item was .23-.55. The test-retest reliability was excellent. There were significant correlations between the 10 candidate and 20 matched detailed items. The score of the 10 candidate items was significantly different according to gender, education level and oral health-related variables. The final five items for the OMFI were difficulties in chewing, the necessity of water when eating dry food, difficulties in jaw or tongue movements, difficulties in speaking or pronunciation and difficulties in facial expression. CONCLUSIONS: The five items could be used as a screening tool for evaluating oral and maxillofacial frailty in older adults.

Blood contamination in salivary diagnostics: current methods and their limitations.

The use of saliva samples in clinical studies has increased. However, the diagnostic value of whole saliva is compromised in the presence of blood contamination, owing to the higher levels of analytes in blood compared with those in saliva. The aim of this study was to review the existing methods and their limitations for measuring the levels of blood contamination in saliva. A literature search was performed using Web of Science, SCOPUS, and PubMed databases and 49 articles dealing with salivary diagnostics and measurements of blood contamination were included. Five methods for measuring the degree of blood components in saliva were discussed, including "visual inspection", use of "strip for urinalysis", and detection of plasma proteins such as "hemoglobin", "albumin", and "transferrin". Each method has its limitations, and transferrin has been regarded as the most reliable and valid marker for blood contamination in saliva. However, transferrin in whole saliva may not be solely a product of blood, and its level in whole saliva can be influenced by several factors such as age, gonadal hormones, salivary flow rate, chewing performance, and oral microorganisms. In conclusion, when quantitatively analyzing whole saliva samples, the influence of blood contamination should be considered.

Clinical factors affecting salivary transferrin level, a marker of blood contamination in salivary analysis.

BACKGROUND: Diagnostic value of whole saliva may be compromised when blood contamination is present in saliva samples. Measuring transferrin level in saliva samples has been used for detecting the level of blood contamination in saliva. The aim of this study was to investigate the validity of transferrin as a proper biomarker for blood contamination in whole saliva. METHODS: Thirty younger (mean age: 25.9 ± 2.1 years) and twenty older (mean age: 65.1 ± 9.0 years) females were included. The index reflecting overall gingival inflammation (total gingival index), salivary flow rate, and salivary concentration and secretion rate of transferrin of each subject were analyzed. RESULTS: Salivary transferrin concentrations and secretion rates were higher in the younger females than in the older ones despite a lower total gingival index in the younger females. The total gingival index showed no significant correlations with the concentration or secretion rate of transferrin in either unstimulated or stimulated whole saliva of younger and older subjects. The salivary concentration of transferrin showed negative correlations with the flow rate of saliva in both the younger and older groups. There were significant positive correlations between the salivary concentrations and secretion rates of transferrin in both the younger and older groups. CONCLUSIONS: Salivary transferrin levels could be affected by other factors as well as the level of blood contamination. The influences of age, gonadal hormones, salivary flow rate, and chewing performance need to be considered when using the salivary level of transferrin as a blood contamination marker.

Polymorphisms of interleukin-1ß and MUC7 genes in burning mouth syndrome.

OBJECTIVE: The objectives of the present study are to compare polymorphisms of the IL-1ß and MUC7 genes between patients with burning mouth syndrome (BMS) and controls and to investigate relationships between these polymorphisms and clinical characteristics in BMS patients. MATERIALS AND METHODS: Forty female BMS patients and 40 gender- and age-matched controls were included. Genomic DNA was extracted from saliva samples. Single-nucleotide polymorphisms of IL-1ß -511 and +3954 and variation in number of tandem repeat (VNTR) polymorphism of MUC7 were analyzed. Relationships between genotypic polymorphism data and clinical characteristics in BMS patients were also analyzed. RESULTS: There were no significant differences in the genotypes of IL-1ß -511 and +3954 and of MUC7 between the groups. There were no significant differences in symptom duration and intensity of BMS patients according to their IL-1ß and MUC7 genotypes. The T allele of IL-1ß -511 showed associations with psychometry results in BMS patients: paranoid ideation (P = 0.014), Global Severity Index (P = 0.025), and Positive Symptom Total (P = 0.008). CONCLUSIONS: The genotypic polymorphisms of IL-1ß -511 and +3954, and of MUC7 VNTR, had no direct associations with the development of BMS. However, the T allele of IL-1ß -511 may increase the risk of BMS by increasing psychological asthenia. CLINICAL RELEVANCE: The genotypic polymorphisms of IL-1ß -511 may increase the risk for the development of BMS by increasing psychological asthenia.

Oral manifestations in vitamin B12 deficiency patients with or without history of gastrectomy.

BACKGROUND: The purpose of this study was to compare clinical features of vitamin B12 deficiency patients with a history of gastrectomy to those without a history of gastrectomy. METHODS: Twenty-two patients with vitamin B12 deficiency were included. Patients' chief complaints, oral manifestations, blood examination results, and past medical histories were reviewed. RESULTS: Eleven patients had a history of gastrectomy and 11 did not. The chief complaint was glossodynia in all patients. No significant differences were observed between the two groups regarding age, sex, symptom duration, or plasma vitamin B12 level. Erythema and depapillation of the tongue were the most common findings, however less common among patients without a history of gastrectomy. Two patients with a history of gastrectomy and 5 patients without a history of gastrectomy had normal oral mucosa. Patients with a history of gastrectomy were more anemic. Oral symptoms of the majority of patients responded to antifungals and vitamin B12 replacement. The suggested etiologies for vitamin B12 deficiency in the patients without a history of gastrectomy were gastritis, medications, diet, autoimmunity, and early gastric cancer. CONCLUSIONS: Vitamin B12 deficiency and its associated etiological factors should be considered in patients with glossodynia, even those whose oral mucosa appears normal and who lack a history of gastrectomy.

Characteristics of men and premenopausal women with burning mouth symptoms: a case-control study.

OBJECTIVES: To identify possible clinical differences between male, premenopausal, and postmenopausal female patients with burning mouth symptoms. BACKGROUND: Burning mouth symptoms are known to occur predominantly in postmenopausal women. In some rare cases, however, such symptoms may also appear in men and younger premenopausal women. There is no information on the characteristics of male and premenopausal female patients with burning mouth symptoms. METHODS: A total of 22 male patients (no age limit) and 19 relatively younger premenopausal female patients (age: ≤45 years) with a burning sensation in the mouth without any visible signs of oral mucosal diseases were included in the experimental groups. Sixty burning mouth patients (postmenopausal females, age: ≥50 years) without oral mucosal diseases were included as a typical older postmenopausal group for comparison. All individuals in the 3 groups were subjected to clinical evaluations including an interview, a comprehensive questionnaire, a simplified psychological evaluation (Symptom Checklist-90-Revision [SCL-90-R]), blood tests, and a measurement of salivary flow rate. RESULTS: The male group reported taste problems less commonly (40.9%, P = .009) and less severely (median visual analog scale [VAS] = 0.00, P = .004) than the postmenopausal group (73.3%, median VAS = 4.50). The younger premenopausal group complained of paresthesia more commonly (68.4%, P = .006) and more severely (median VAS = 0.50, P = .007) than the postmenopausal group (30.0%, median VAS = 0.00). The male group (81.8%) reported discomfort of the tongue less commonly than the postmenopausal group (100.0%, P = .004). The percentage of patients with a symptom triad of oral mucosal pain, dysguesia, and xerostomia was significantly higher in the premenopausal (73.7%, P = .005) and postmenopausal (60.0%, P = .012) groups than the male group (27.3%). The flow rate of unstimulated whole saliva was significantly higher in the premenopausal group (0.27 ± 0.18 mL/min) than the postmenopausal group (0.17 ± 0.16 mL/min, P = .006). None of the 9 symptom dimensions of the SCL-90-R were significantly different among the 3 groups. The percentage of patients with abnormal blood tests and taking medications due to comorbid diseases was the lowest in the premenopausal group. CONCLUSIONS: Male and premenopausal female patients with burning mouth symptoms showed different characteristics compared with typical postmenopausal female patients.

Yam tuber mucilage as a candidate substance for saliva substitute: in vitro study of its viscosity and influences on lysozyme and peroxidase activities.

OBJECTIVE: To investigate the viscosity of yam tuber mucilage (YTM) and its effects on lysozyme and peroxidase activities in solution phase and on surface phase. METHODS: Two kinds of YTM were extracted, one containing both protein and carbohydrate and the other containing mainly carbohydrate. Hen egg-white lysozyme and bovine lactoperoxidase were used as lysozyme and peroxidase sources, respectively. Viscosity was measured with a cone-and-plate digital viscometer. Lysozyme activity was determined using the turbidimetric method, and peroxidase activity was determined using the NbsSCN assay. Hydroxyapatite beads were used as a solid phase. RESULTS: The viscosity values of YTM followed a pattern of a non-Newtonian fluid. The carbohydrate concentration affected the viscosity values at all shear rates, while the protein concentration affected the viscosity values at low shear rates. It could be suggested that YTM composed of 1.0 mg/ml protein and 1.0 mg/ml carbohydrate has viscosity values similar to those of unstimulated whole saliva at shear rates present at routine oral functions. Hydroxyapatite-adsorbed YTM significantly increased the adsorption and subsequent enzymatic activities of lysozyme, but not those of peroxidase. CONCLUSIONS: Yam tuber mucilage has viscoelastic properties similar to those of human saliva and enhances the enzymatic activity of lysozyme on hydroxyapatite surfaces.

In Vitro Effects of Zinc Compounds on the Candidacidal Activities of Salivary Antimicrobials.

OBJECTIVE: This study aimed to investigate the effects of zinc compounds on the candidacidal activities of lysozyme and the peroxidase (PO) and glucose oxidase-mediated peroxidase (GO-PO) systems against Candida albicans. METHODS: Four zinc compounds were used: zinc chloride, gluconate, lactate, and sulphate. Three antimicrobial systems were used: hen egg-white lysozyme (HEWL), the PO system [bovine lactoperoxidase (bLPO), potassium thiocyanate, and hydrogen peroxide], and the GO-PO system (bLPO, potassium thiocyanate, glucose oxidase, and glucose). Three Candida albicans strains were used: ATCC 10231, 11006, and 18804. The candidacidal activity of each zinc compound-antimicrobial system mixture was compared with that of the zinc compound or antimicrobial system alone. RESULTS: The addition of zinc chloride and gluconate significantly (P < .05) increased the candidacidal activity of HEWL in the ATCC 10231 and 11006 strains. Regarding the PO system, the addition of zinc sulphate in the ATCC 10231 strain and of zinc chloride or gluconate in the ATCC 18804 strain significantly (P < .05) increased the candidacidal activity compared with the PO system alone. No significant changes were observed in the candidacidal activities of the mixture of each zinc compound and the GO-PO system compared with the GO-PO system alone for all three C. albicans strains. CONCLUSIONS: Although it depended on the type of zinc compound or strain, the addition of zinc compounds increased the candidacidal activities of antimicrobial enzymes against C. albicans compared with HEWL or the PO system alone. The introduction of zinc compounds into oral healthcare products containing antimicrobials could provide additional antifungal activity.

Effects of preservatives on the activities of salivary enzymes.

OBJECTIVES: To investigate the effects of common preservatives used in oral health care products on the enzymatic activities of lysozyme, peroxidase, and α-amylase in-solution and on-hydroxyapatite surface phases. DESIGN: The preservatives used in this study were sodium benzoate, methylparaben, propylparaben, and benzalkonium chloride. Hen egg-white lysozyme, bovine lactoperoxidase, and α-amylase from Bacillus sp. served as sources of purified enzymes. Human unstimulated whole saliva was used as a source of salivary enzymes. Hydroxyapatite beads were used as the surface phase. The preservatives were incubated with purified enzymes or saliva samples in-solution or on-hydroxyapatite surface phases, respectively. Enzymatic activities of lysozyme, peroxidase, and α-amylase were measured by hydrolysis of fluorescein-labelled Micrococcus lysodeikticus, oxidation of fluorogenic 2',7'-dichlorofluorescin, and hydrolysis of fluorogenic starch, respectively. RESULTS: The effects of the preservatives on the enzymatic activities of lysozyme and peroxidase were more distinct in the saliva samples than purified substances, and in the in-solution phase than on-hydroxyapatite surface phase, and the opposite was true for α-amylase. The most significant result was apparent decrease in peroxidase activities caused by the parabens in the in-solution phase (P<0.05). Sodium benzoate and parabens inhibited lysozyme activity in the in-solution phase, but differently for the purified and salivary lysozymes. Parabens and benzalkonium chloride inhibited the enzymatic activity of α-amylase from Bacillus sp., not saliva samples, only on-hydroxyapatite surface (P<0.05). CONCLUSIONS: Each preservative affected the enzymatic activities of lysozyme, peroxidase, and α-amylase differently. Based on the effects on salivary enzymes, sodium benzoate or benzalkonium chloride was recommended as preservatives rather than parabens.

Effects of Zinc Compounds on the Enzymatic Activities of Lysozyme and Peroxidase and Their Antifungal Activities.

This study aimed to investigate the effects of zinc compounds on the enzymatic activities of lysozyme, peroxidase, and the glucose oxidase-mediated peroxidase (GO-PO) system and their antifungal activities. Four different zinc compounds (zinc chloride, gluconate, lactate, and sulfate) were incubated with hen egg-white lysozyme (HEWL), bovine lactoperoxidase (bLPO), the GO-PO system, and human unstimulated whole saliva in solution and on a hydroxyapatite surface. Enzymatic activities of lysozyme, peroxidase, and the GO-PO system were measured through the hydrolysis of Micrococcus lysodeikticus, oxidation of fluorogenic 2',7'-dichlorofluorescin, and glucose assay, respectively. Interactions between zinc and enzymes were analyzed by surface plasmon resonance (SPR). The minimum inhibitory concentration (MIC) and candidacidal activities of zinc compounds were examined against three Candida albicans strains. Zinc gluconate and sulfate significantly increased the enzymatic activities of salivary lysozyme in the solution assay and of HEWL and salivary lysozyme on the hydroxyapatite surface. However, all examined zinc compounds significantly decreased the enzymatic activities of bLPO and salivary peroxidase in solution and on the surface. SPR analyses revealed binding of zinc to lysozyme and peroxidase, with affinity differing according to the zinc compounds. The MIC of zinc compounds against C. albicans was 1.0-2.4 mM. Candidacidal activities were 17.7-38.8% and 23.7-47.0% at 1.0 and 10 mM concentrations, respectively. In conclusion, zinc compounds enhanced lysozyme activity but inhibited peroxidase activity. Zinc compounds exhibited concentration-dependent candidacidal activity against C. albicans. Zinc compounds are potential therapeutic agents for oral health, especially for geriatric patients.