Effect of denture adhesives on masticatory performance: Multicenter randomized controlled trial.

PURPOSE: The purpose of this study is to investigate the effects of denture adhesives on masticatory performance via a 10-center, parallel, randomized, controlled trial of complete denture wearers in Japan. METHODS: The trial was conducted between September 2013 and October 2016. The inclusion criteria were complete edentulism, willingness to undergo new complete denture treatment, and willingness to return for recall treatment. The exclusion criteria were age 90 years or older, presence of severe systemic illness, inability to understand the questionnaires, wearing metal base complete dentures, denture adhesive user, wearing prosthetics for maxillofacial defects, wearing complete dentures with tissue conditioners, and severe xerostomia. Randomization of the powder-type denture adhesive (powder), cream-type denture adhesive (cream), and control (saline) groups was performed using a sealed envelope system. Masticatory performance was measured using color-changeable chewing gum. Intervention blinding was not feasible. RESULTS: Sixty-seven control, 69 powder, and 64 cream participants are analyzed using the intention-to-treat principle. The participants in all groups show significantly improved masticatory performance at post-intervention (paired t-test with Bonferroni correction P < 0.0001). However, no significant difference in masticatory performance is detected among the three groups (one-way analysis of variance). A significant negative correlation between pre- and post-changes in masticatory performance and intraoral condition scores is observed (Pearson's correlation coefficient, P < 0.0001). CONCLUSIONS: Although denture adhesives improved the masticatory performance of complete denture wearers, their clinical effects are comparable to those of saline solution. The use of denture adhesives is more effective in complete denture wearers with unsatisfactory intraoral conditions.

Effects of denture adhesives on denture retention and occlusal forces in complete denture wearers: A multicenter, randomized controlled trial.

PURPOSE: This study aimed to determine the effects of denture adhesives on denture retention and occlusal force in complete denture wearers in a multicenter, randomized, parallel-group controlled trial. METHODS: Two hundred edentulous patients wearing complete dentures were allocated to three groups: powder-type denture adhesive, cream-type denture adhesive, and control (saline solution). Denture adhesives and saline solution were applied to the dentures for 4 days. The retentive force of the dentures and occlusal force were measured using a force transducer occlusal force meter at baseline and after 4 days of intervention. In addition to between-group comparisons, subgroup analyses of denture retention and occlusal force were performed based on the level of difficulty of the edentulism treatment. The levels were ranked as I (easy), II, III, and IV (difficult). RESULTS: Cream-type denture adhesives significantly improved the retentive force of the dentures (P<0.01) and occlusal force (P<0.05), with no significant differences between baseline and post-intervention forces in the powder-type denture adhesive and control groups. In within-group comparisons, cream-type denture adhesives improved both the retentive and occlusal forces at Level II (P<0.05), and powder-type denture adhesives improved the occlusal force at Level II (P<0.01). CONCLUSIONS: Application of cream-type denture adhesives effectively improves the denture retention and occlusal force in complete denture wearers with a moderate degree of difficulty during edentulism treatment.

Multivariate analysis reveals oral health-related quality of life of complete denture wearers with denture adhesives: a multicenter randomized controlled trial.

Purpose To investigate the difference in improvement of oral health-related quality of life (OHR-QoL) depending on the oral and denture conditions of a complete denture wearer when using a cream or powder type denture adhesive in a 10-center parallel randomized clinical trial.Methods Two hundred edentulous subjects who wore complete dentures were allocated to each of the three groups according to denture adhesive type: cream, powder, and control (saline solution). The materials were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention were collected. OHR-QoL was assessed using the Japanese version of the modified Oral Health Impact Profile for Edentulous Patients (OHIP-EDENT-J) scale for outcome. Multivariate analysis was used to investigate improvements in OHR-QoL according to participant characteristics among complete denture wearers using these materials.Results OHIP-EDENT-J scores were significantly decreased in all groups after the intervention (p < 0.05); however, there were no statistically significant differences among the groups. Multiple logistic regression analysis revealed a significant association between the vertical height of the maxillary and mandibular alveolar ridge and OHIP-EDENT-J scores in the cream-type denture adhesive group. In contrast, there were no significant association between participant characteristics and OHIP-EDENT-J scores in the powder-type adhesive and control groups.Conclusions The use of denture adhesives could improve OHR-QoL for complete denture wearers. The cream-type denture adhesives may be expected to improve OHR-QoL in patients with poor residual ridge conditions compared with patients with good residual ridge conditions.

Food intake and oral health status of inpatients with dysphagia in acute care settings.

Adequate oral status and functional assessments are important for dysphagia rehabilitation in acute care inpatient settings, especially to establish individualised oral intake. However, the association between food intake levels and oral function has not been elucidated in acute care inpatients. This cross-sectional study clarified the association between oral intake levels and the oral status/function of patients with dysphagia admitted to acute care settings. Admitted patients aged ≥40 years (n = 459; men: 288; mean age: 70.8 ± 12.0) examined at the Department of Dysphagia Rehabilitation at the Iwate Medical University Hospital from April 2007 to March 2014 were included. The oral health status was evaluated by the tongue coating, oral dryness severity, plaque control, posterior occlusal support and a repetitive saliva swallowing test (RSST). Dysphagia severity was determined from the Dysphagia Severity Scale. Oral intake levels were evaluated using the Functional Oral Intake Scale (FOIS) at the time of the initial dental examination (FOIS-I), and they were re-evaluated after the revision of levels according to the participants' general condition and oral health status (FOIS-R). Divergence between FOIS-I and FOIS-R was noted in >40% patients. Multiple regression analysis showed significant associations between FOIS-R and consciousness level, activities of daily living, tongue coating, RSST and posterior occlusal support. Patients with dysphagia in acute care settings require detailed assessments of their oral status and function, including swallowing, to determine the most suitable feeding methods and dental interventions to improve oral intake levels.

Effects of denture adhesives on growth and morphological transformation of Candida albicans.

PURPOSE: We investigated the effects of denture adhesives (cream (Cr), powder (Po), and cushion (Cu)) on growth and adhesive-related morphological transformation of Candida albicans. For this purpose, the numbers of adherent C. albicans, hyphae-specific gene expressions, and the SEM images were examined. METHODS: Acrylic resin blocks were prepared as controls (Co). Cr, Po, and Cu were thinly spread on the surface of the resin block.C. albicans suspension was seeded on the specimens and incubated at 4 °C for 2 h. The numbers of C. albicans adhering to each specimen at each incubation time period (1, 2, 3, 6, 12, and 24 h) were quantified using real-time RT-PCR. The hyphae-specific genes expressions were examined. The surface of each specimen was observed under the SEM to detect the transformation to the hyphal form. RESULTS: The initial adhesion rates in all groups were not statistically significant. The numbers of C. albicans adhering increased with time in all groups, and those adhering to the Cr, Po, and Cu were significantly greater than that adhering to the Co. In the Cr and Po, the hyphal-specific genes expressions were higher after incubation for 6 h. The transformation to the hyphal form was identified in the Cr and Po after incubation for 6 and 12 h. CONCLUSIONS: The denture adhesives used in this study accelerated the growth of C. albicans. Moreover, the early transformation to the hyphal form on the Cr- and Po-type adhesives was observed, suggesting that we should carefully use Cr- and Po-type adhesives.

Oral mucosa pressure caused by mandibular implant overdenture with different types of attachments.

PURPOSE: To determine the appropriate attachment and design of a denture base for mandibular implant overdenture (IOD), the oral mucosa pressure caused by mandibular implant overdentures was measured using edentulous jaw models with various attachments. METHODS: An experimental edentulous mandibular model with a 1.5-mm thick artificial oral mucosa was used. Two implants were placed at the area equivalent to the bilateral canines of an experimental jaw model. Locator attachments (LA), ball attachments (BA), magnetic attachments (MA), and round-bar attachments (R-BA) were fabricated. Six miniature pressure sensors were placed at the bilateral buccal premolar regions, bilateral buccal shelves, and bilateral lingual molar regions. A precision universal testing machine was used to apply dynamic repetitive loads of 50N. The load points were the center of the model, which should represent bilateral mastication on both sides (bilateral load), and were equivalent to the left first molar, which should represent unilateral mastication (unilateral load). Statistical analysis was performed using one-way analysis of variance. Multiple comparisons were then performed using the Bonferroni post hoc test. P<0.05 was considered statistically significant. RESULTS: Under the bilateral load condition, the lower oral mucosa pressure value with BA was measured, compared to other attachments at all measurement sites. Under the unilateral load condition, the oral mucosa pressure value of BA was smaller than the other attachments at the measurement site on the loading side. CONCLUSIONS: BA has exerted the greatest effects on support and bracing, suggesting that, BA is suitable for reducing oral mucosa pressure during mastication.

Effect of denture adhesives on oral moisture: A multicenter randomized controlled trial.

PURPOSE: The purpose of this study was to investigate the effect of denture adhesives on oral moisture in a 10-center parallel randomized clinical trial. METHODS: Two hundred edentulous subjects wearing complete dentures were allocated into three groups: cream-type adhesive, powder-type adhesive and control groups. The adhesives (and saline solution in the control group) were applied to the mucosal surface of the dentures for 4 days, and baseline data and data after the intervention for eight meals over 4 days were obtained. For the main outcome, oral moisture was measured with a moisture checking device. Secondary outcomes were denture satisfaction, masticatory performance, denture retention, and occlusal force. In addition to between-group and within-group comparisons of oral moisture, investigations for secondary outcomes were undertaken in subgroups classified according to the degree of oral moisture at baseline (normal subgroup and dry mouth subgroup). Intention-to-treat analysis was also performed. RESULTS: Between-group and within-group comparisons of oral moisture showed no significant differences. The cream-type and powder-type denture adhesives were significantly effective in the dry mouth group for denture satisfaction ratings of ability to masticate, stability, retention, and comfort of mandibular dentures (p<0.05). The masticatory performance and retentive force of the dry mouth denture adhesive using groups were significantly improved after intervention (p<0.05). CONCLUSIONS: The oral moisture of complete denture wearers was not influenced by the use of denture adhesives. Our findings showed that denture adhesives improved subjective denture satisfaction, masticatory performance, and retention for complete denture patients with oral dryness.

Effects of tooth loss on brain structure: a voxel-based morphometry study.

PURPOSE: One of the most prominent issues in a super-aging society is the rapid increase in dementia patients. Cross-sectional studies in dentistry have indicated that patients with dementia have worse oral health compared to healthy people. The purpose of this study was to clarify the influence of tooth loss on brain structure by comparing the volumes of gray matter (GM) and white matter (WM) between edentulous and dentulous subjects. METHODS: Subjects were recruited from the Denture Clinic at Iwate Medical University Hospital Dental Center. Experiments were performed on edentulous (5 males, 8 females, 81.8±1.24years) and dentulous subjects (4 males, 7 females, 77.1±4.25years). Patients with dementia were excluded from this study. Brain volumes of GM and WM in edentulous and dentulous subjects were compared using intracranial volume, age, gender and history of hypertension as covariates. Analyzed brain areas were identified by transforming the Montreal Neurological Institute coordinate into the anatomical coordinate in edentulous subjects. RESULTS: The analysis of WM structural images found no morphological differences between dentulous and edentulous subjects. However, significant atrophy of GM was observed in the hippocampus, caudate nucleus and temporal pole of the right hemisphere in edentulous subjects. CONCLUSIONS: The results of this study suggest that tooth loss was a causal factor for volume reduction in brain areas related to memory, learning and cognition.

Study protocol for a multi-center, randomized controlled trial to develop Japanese denture adhesive guidelines for patients with complete dentures: the Denture Adhesive Guideline trial: study protocol for a randomized controlled trial.

BACKGROUND: Denture adhesives, characterized as medical products in 1935 by the American Dental Association, have been considered useful adjuncts for improving denture retention and stability. However, many dentists in Japan are hesitant to acknowledge denture adhesives in daily practice because of the stereotype that dentures should be inherently stable, without the aid of adhesives. The aim of this study is to verify the efficacy of denture adhesives to establish guidelines for Japanese users. The null hypothesis is that the application of denture adhesives, including the cream and powder types, or a control (isotonic sodium chloride solution) would not produce different outcomes nor would they differentially improve the set outcomes between baseline and day 4 post-application. METHODS: This ten-center, randomized controlled trial with parallel groups is ongoing. Three hundred edentulous patients with complete dentures will be allocated to three groups (cream-type adhesive, powder-type adhesive, and control groups). The participants will wear their dentures with the denture adhesive for 4 days, including during eight meals (three breakfasts, two lunches, and three dinners). The baseline measurements and final measurements for the denture adhesives will be performed on the first day and after breakfast on the fourth day. The primary outcome is a general satisfaction rating for the denture. The secondary outcomes are denture satisfaction ratings for various denture functions, occlusal bite force, resistance to dislodgement, masticatory performance, perceived chewing ability, and oral health-related quality of life. Between-subjects comparisons among the three groups and within-subjects comparisons of the pre- and post-intervention measurements will be performed. Furthermore, a multiple regression analysis will be performed. The main analyses will be based on the intention-to-treat principle. A sample size of 100 subjects per group, including an assumed dropout rate of 10 %, will be required to achieve 80 % power with a 5 % alpha level. DISCUSSION: This randomized clinical trial will provide information about denture adhesives to complete denture wearers, prosthodontic educators, and dentists in Japan. We believe this new evidence on denture adhesive use from Japan will aid dentists in their daily practice even in other countries. TRIAL REGISTRATION: ClinicalTrials.gov NCT01712802 . Registered on 17 October 2012.

Wearing complete dentures is associated with changes in the three-dimensional shape of the oropharynx in edentulous older people that affect swallowing.

OBJECTIVE: To investigate the effects of wearing complete dentures on pharyngeal shape for swallowing in edentulous older people. BACKGROUND: In the absence of complete dentures, edentulous older people often lose the occlusal support necessary to position the mandible, which leads to an anterosuperior shift of the mandible during swallowing. This may result in pharyngeal shape changes effecting swallowing function in older people. However, the details of this phenomenon are currently unclear. MATERIALS AND METHODS: Participants were 17 older edentulous volunteers. Cone-beam computed tomography imaging was performed with the participant in the seated position and wearing (i) both maxillary and mandibular dentures, (ii) maxillary dentures only and (iii) no dentures. During imaging, participants were instructed to keep their mouth closed to the mandibular position determined in advance during swallowing for each denture-wearing condition. The volume, height and average cross-sectional area of the velopharynx and oropharynx were measured, and the positions of the epiglottis and mandible were recorded. RESULTS: While the vertical height of the oral cavity and pharynx significantly decreased, the volume and average cross-sectional area of the oropharynx significantly increased when dentures were not worn (p < 0.01). The absence of dentures caused an anterosuperior shift of the mandible when swallowing and drew the epiglottis forward, resulting in expansion of the oropharynx where the tongue base forms the anterior wall. CONCLUSION: The absence of dentures results in anatomical changes in oropharyngeal shape that may exacerbate the pharyngeal expansion caused by ageing and reduce the swallowing reserve.

Chemistry and biosynthesis of isoprenylated flavonoids from Japanese mulberry tree.

Many isoprenylated flavonoids have been isolated from Japanese mulberry tree (Moraceae). Among them, kuwanons G (1) and H (2) were the first isolated active substances exhibiting a hypotensive effect. These compounds are considered to be formed through an enzymatic Diels-Alder type reaction between an isoprenyl portion of an isoprenylphenol as the diene and an alpha, beta-double bond of chalcone as the dienophile. The absolute configurations of these Diels-Alder type adducts were confirmed by three different methods. The stereochemistries of the adducts were consistent with those of ones in the Diels-Alder reaction involving exo- and endo-addition. Some strains of Morus alba callus tissues have a high productivity of mulberry Diels-Alder type adducts, such as chalcomoracin (3) and kuwanon J (4). The biosynthetic studies of the mulberry Diels-Alder type adducts have been carried out with the aid of the cell strain. Chalcomoracin (3) and kuwanon J (4) were proved to be enzymatic Diels-Alder type reaction products by the administration experiments with O-methylchalcone derivatives. Furthermore, for the isoprenoid biosynthesis of prenylflavonoids in Morus alba callus tissues by administration of [1,3-(13)C(2)]- and [2-(13)C]-glycerol, a novel way through the junction of glycolysis and pentose-phosphate cycle was proved. Two independent isoprenoid biosynthetic pathways, that for sterols and that for isoprenoid-phenols, operate in the Morus alba cell cultures. The former is susceptible to compactin (ML-236) and the latter resists to compactin in the cell cultures, respectively.

Triterpenoids from Peganum nigellastrum.

Two triterpenoids were isolated from the roots of Peganum nigellastrum Bunge. Their structures were elucidated as 3alpha-acetoxy-27-trans-caffeoyloxyolean-12-en-28-oic acid methyl ester (1) and 3-oxotirucalla-7, 24-dien-21-oic acid (2) on the basis of spectroscopic evidence. 1 is a new triterpene ester and 2 is a known compound isolated for the first time from genus Peganum.

A new 2-arylbenzofuran from the root bark of Chinese Morus cathayana.

A new 2-arylbenzofuran, sanggenofuran B (3',5'-dihydroxy-6-methoxy-4'-prenyl-2-arylbenzofuran), from the root bark of Chinese Morus cathayana is reported.

Hypoglycemic effect of Egyptian Morus alba root bark extract: effect on diabetes and lipid peroxidation of streptozotocin-induced diabetic rats.

The hypoglycemic activity of the flavonoids rich fraction of 70% alcohol extract of the Egyptian Morus alba root bark (MRBF-3) was evaluated after its oral administration to streptozotocin-induced diabetic rats. Diabetes was induced by injection of 60 mg kg(-1) i.p. The administration of MRBF-3 to streptozotocin (STZ)-diabetic rats for 10 days in a dose of 200 and 400 mg kg(-1)day(-1) was not significant. However, administration of MRBF-3 for 10 days (600 mg kg(-1)day(-1)) significantly reduced the amount of the glucose from control level (379+/-9 mg/dl) to a lower level (155+/-8 mg/dl) and significantly increased the insulin level from control (10.8+/-0.3 microU/ml) to a high level (15.6+/-0.3 microU/ml). The measurement of produced lipid peroxides (expressed as the amount of thiobarbituric acid (TBA) reactive substance, nmol TBARS/ml serum) indicated antiperoxidative activity of MRBF-3. The oral administration of MRBF-3 to STZ-diabetic rats significantly decreased the lipid peroxides from 6.3+/-0.8 to 5.1+/-0.7 nmol TBARS/ml serum. The phytochemical investigation of MRBF-3 resulted in the isolation of four hydrophobic flavonoids with one or two isoprenoid groups (log P=5-9): morusin, cyclomorusin, neocyclomorusin, and kuwanon E, a 2-arylbenzofuran, moracin M, and two triterpenes, betulinic acid and methyl ursolate. The data obtained from this study revealed that MRBF-3 may protect pancreatic beta cells from degeneration and diminish lipid peroxidation. However, this is the first biological screening of the Egyptian Morus alba root bark; further future merit studies including clinical study will be necessary in order to confirm the results obtained from this study.

Novel quinazoline-quinoline alkaloids with cytotoxic and DNA topoisomerase II inhibitory activities.

Two new synthetic analogues of luotonins A and F, 7-acetylaminoluotonin A (6) and 3-[3H(quinazolino-4-one)]quinoline (7) were synthesized. The new analogues, along with four natural quinazoline-quinoline alkaloids, luotonins A (1), B (2), E (3), F (4) and a synthetic deoxoluotonin F (5), showed cytotoxic activity (IC(50) 1.8-40.0 microg/mL) and DNA topoisomerase II inhibition at a concentration of 25 microM.

Preliminary evaluation of antinephritis and radical scavenging activities of glabridin from Glycyrrhiza glabra.

Antinephritis activity of glabridin, a pyranoisoflavan isolated from Glycyrrhiza glabra, was evaluated after its oral administration to mice with glomerular disease (Masugi-nephritis) by measuring the urinary protein excretion, total cholesterol, serum creatinine and blood urea nitrogen levels. Administration of glabridin for 10 days (30 mg kg(-1) day(-1)) reduced the amount of urinary protein excretion from control level (100+/-23 mg/day) to a significantly lower level (47+/-4 mg/day). ESR spectroscopy demonstrated that glabridin neither produced radical, nor affected the radical intensity of sodium ascorbate, suggesting the lack of correlation between the antinephritis activity and radical scavenging activity.

Antinephritis and radical scavenging activity of prenylflavonoids.

Antinephritis activity of 5 prenylflavonoids similar to glabridin (1-5), isolated from Morus alba, Artocarpus communis, Glycyrrhiza uralensis and G. inflata, was evaluated in mice with glomerular disease (Masugi-nephritis). Oral administrations of artonin E (2) or licochalcone A (4) for 10 days (30 mg kg(-1) day(-1)) reduced the amount of urinary protein excretion compared to nephritic mice. ESR spectroscopy demonstrated that morusin (1) and licorisoflavan A (5) increased the radical intensity of sodium ascorbate by about two times. Morusin, licoricidin (3), licochalcone A and licorisoflavan A showed weak scavenging activity against superoxide anion radical.

Antifungal agents from the roots of Cudrania cochinchinensis against Candida, Cryptococcus, and Aspergillus species.

Bioassay-guided fractionation resulted in the isolation of four antifungal agents from the roots of Cudrania cochinchinensis. Two of these were new compounds, cudraxanthone S [1, 1,3,5,6-tetrahydroxy-2-(1,1-dimethyl-2-propenyl)xanthone] and cudraflavanone B (2, 2',4',5,7-tetrahydroxy-6-prenylflavanone). The remaining two compounds were known compounds, toxyloxanthone C (3) and wighteone (4). Among these compounds, 1, 3, and 4 exhibited antifungal activities against Cryptococcus neoformans, Aspergillusfumigatus, and A. nidulans (MICs = 2-8 microg/mL). Compounds 1 and 3 also showed antifungal activity against Candida glabrata (MICs = 4-8 microg/mL).

Antimicrobial activity of licorice flavonoids against methicillin-resistant Staphylococcus aureus.

Nineteen flavonoids isolated from licorice (Glycyrrhiza glabra, G. inflata and G. uralensis) were tested for their antimicrobial activities against methicillin sensitive Staphylococcus aureus, methicillin resistant S. aureus, Micrococcus luteus, Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa.

Anti-Helicobacter pylori flavonoids from licorice extract.

Licorice is the most used crude drug in Kampo medicines (traditional Chinese medicines modified in Japan). The extract of the medicinal plant is also used as the basis of anti-ulcer medicines for treatment of peptic ulcer. Among the chemical constituents of the plant, glabridin and glabrene (components of Glycyrrhiza glabra), licochalcone A (G. inflata), licoricidin and licoisoflavone B (G. uralensis) exhibited inhibitory activity against the growth of Helicobacter pylori in vitro. These flavonoids also showed anti-H. pylori activity against a clarithromycin (CLAR) and amoxicillin (AMOX)-resistant strain. We also investigated the methanol extract of G. uralensis. From the extract, three new isoflavonoids (3-arylcoumarin, pterocarpan, and isoflavan) with a pyran ring, gancaonols A[bond]C, were isolated together with 15 known flavonoids. Among these compounds, vestitol, licoricone, 1-methoxyphaseollidin and gancaonol C exhibited anti-H. pylori activity against the CLAR and AMOX-resistant strain as well as four CLAR (AMOX)-sensitive strains. Glycyrin, formononetin, isolicoflavonol, glyasperin D, 6,8-diprenylorobol, gancaonin I, dihydrolicoisoflavone A, and gancaonol B possessed weaker anti-H. pylori activity. These compounds may be useful chemopreventive agents for peptic ulcer or gastric cancer in H. pylori-infected individuals.