An in vitro study on the selection of surfactants for removal of cream denture adhesives from dentures and their application to denture cleaners.

Purpose Denture adhesives improve the stability of incompatible dentures; however, complete removal of adhesives after use is difficult. Only a few studies have focused on the removal of denture adhesives. Hence, this study aimed to assess the efficacy of surfactants in removing cream denture adhesives from acrylic resin materials.Methods Solutions of twelve surfactants with various hydrophilic-lipophilic balance (HLB) values were prepared. Two cream denture adhesives, colored for visualization, were spread onto transparent acrylic resin plates. After immersion into surfactant solutions, the effects of the surfactants on residual adhesives were evaluated. We also investigated the effect of denture cleaners (with or without the surfactants) on the removability of adhesives and artificial oily dirt, and their effects on the surface properties of denture materials. The obtained data were analyzed using appropriate statistical methods.Results Five surfactants [BT-5, BL-4.2, BT-7, BT-9, and Triton X-100 (TX)] with HLB values in the 10.5-13.5 range effectively removed adhesives. Addition of BT-9 and TX (HLB=13.5) to denture cleaners improved the adhesives' removal. Furthermore, the addition of TX to the cleaners did not interfere with the removal of artificial oily dirt and did not damage the denture materials' surface.Conclusions Surfactants with HLB values in the 10.5-13.5 range are suitable for removal of cream denture adhesives from acrylic resin materials. In particular, TX (HLB=13.5) efficiently removes adhesives without damaging denture materials or impairing original detergency.

Effects of Denture Cleaning Regimens on the Quantity of Candida on Dentures: A Cross-Sectional Survey on Nursing Home Residents.

Oral care involving a denture cleaning regimen is important for reducing the incidence of systemic diseases. However, limited information is currently available on denture cleaning frequencies and regimens. Therefore, the present study investigated the relationship between the number of Candida spp. present on the complete dentures of nursing home residents and cleaning regimens. Residents were surveyed to assess their denture cleaning methods. Plaque was collected by applying a sterile swab to the mucosal surface of each examined complete denture worn by 77 residents, and the Candida spp. collected were cultured, identified, and quantified. The relationship between denture cleaning regimens and the quantity of Candida spp. was investigated. Correlation and multivariable analyses revealed that the strongest factor influencing the number of Candida spp. on dentures was the frequency of use of denture cleansers. The number of Candida spp. was the lowest on dentures cleaned daily with a denture cleanser. The present results demonstrated that the daily use of a denture cleanser effectively controlled the adherence of Candida spp. to dentures. Oral and other healthcare providers need to provide instructions on and assist nursing home residents with the daily care of dentures, using denture cleansers, including the environment where cleaning is performed.

Properties and characteristics of foam denture cleaners as denture adhesive removers.

The need for denture adhesives is increasing worldwide, but few denture-care products target denture adhesive users. Foam denture cleaners have been recently marketed to assist brush denture cleaning, but there is a lack of objective evaluation. In this study, we compared the detergency of denture adhesives using six commercial foam-denture cleaners. For removing the adhesives, most of the tested cleaners were effective in immersion experiments, and three cleaners were more effective in the denture cleaning experiment compared to control water. However, only one could effectively remove the slime that is derived from the adhesive and detergency of artificial dirt. The surface roughnesses of the denture base and the relining material revealed that prolonged immersion in some cleaners could be affected. The results suggest that different commercial foam denture cleaners have different detergency levels, and that some cleaners may affect the properties of denture materials upon long-term use.

Fabrication of a movable obturator following maxillary reconstruction with slit-shaped fenestration.

Extensive maxillary resection has generally been reconstructed with free skin flaps. Because drooping of the transferred flap causes instability of the obturator prosthesis, maxillary reconstruction often incorporates a slit-shaped oronasal fenestration. Although obturator prostheses for edentulous patients are stabilized with the help of oronasal slits, those for dentate patients are unstable because of flap mobility, resulting in a harmful lateral force exerted on the abutment teeth, causing dislodging of the denture. This report evaluates the benefits of a movable obturator prosthesis for a 60-year-old dentulous patient with maxillary sinus carcinoma. The patient underwent left-sided total maxillectomy, and the defect was reconstructed with a slit-shaped fenestration using a rectus abdominis flap. A conventional obturator prosthesis was inserted; however, drooping of the flap caused instability of the obturator, resulting in nasal regurgitation and fracture of the clasp. To solve this problem, we designed an obturator prosthesis with a movable connection consisting of a ball attachment (patrix) in the metal base and a socket (matrix) in the obturator, which acted as a stress breaker against the harmful force exerted by the flap. Application of this movable obturator prosthesis was a useful solution for a compromising situation created by the surgical procedure. No clinical disorders were observed at the 3-year follow-up.

Dry mouth and denture plaque microflora in complete denture and palatal obturator prosthesis wearers.

OBJECTIVE AND BACKGROUND: The purpose of this study was to investigate the association of dry mouth with denture plaque microflora in patients with palatal obturator prostheses from the viewpoint of infection control. METHODS: Thirty palatal obturator prosthesis wearers were compared with 30 healthy maxillary complete denture wearers. Dry mouth was examined using a moisture-checking device and was diagnosed by the measured moisture levels. Denture plaque was collected by rubbing the mucosal surface of the denture with a swab; collected microorganisms were cultured and identified using culture-dependent methods. The number of colonising microorganisms and prevalence of microorganisms were examined according to the type of prostheses and presence of dry mouth using nonparametric tests and frequency analysis (α = 0.05). RESULTS: The prevalence of Candida spp. and Staphylococcus spp. in palatal obturator prostheses was significantly higher than that in complete dentures. In palatal obturator prostheses, the total number of colonising microorganisms showed no significant differences between the groups with and without dry mouth on each side of the prostheses. However, the prevalence of Candida spp. and Staphylococcus spp. in the group with dry mouth was significantly higher than that in the group without dry mouth. The number of microorganisms and moisture levels of palatal obturator prosthesis wearers showed a significantly negative correlation with Candida spp. and Staphylococcus spp., but a positive correlation with Neisseria spp. CONCLUSION: It was concluded that palatal obturator prosthesis wearers with a dry mouth have greater colonisation by Candida spp. and Staphylococcus spp. than do complete denture wearers.

Comparison of a saliva wetness tester and a moisture-checking device in patients with maxillary obturator prostheses.

OBJECTIVE: Examination of dry mouth in postoperative oral tumour patients should ideally be performed simply and quickly at the chair side. Moisture-checking devices and saliva wetness testers are available for such moisture measurement. Previous studies have reported that moisture-checking devices are useful to examine dry mouth in patients with maxillary obturator prostheses. However, because the measurement principles of saliva wetness testers differ from those of moisture-checking devices, diagnosis by the two devices may result in diagnostic disagreement. The purpose of the present study was to compare the usefulness of a saliva wetness tester with a moisture-checking device for patients with maxillary obturator prostheses. METHODS: Oral moisture was measured with a moisture-checking device and a saliva wetness tester in 30 subjects with maxillary obturator prostheses. These measurements were performed five times at the lingual mucosa, and mean values of each measurement were calculated. The reference value for moisture measurements with the moisture-checking device was 29%, and that with the saliva wetness tester was 3 mm. Subjects were classified as having dry mouth when their moisture measurements were less than the reference values. RESULTS: The diagnostic results of the saliva wetness tester were in agreement with those of the moisture-checking device. The respective moisture measurements showed a significant positive correlation (r=0.88, p<0.01). CONCLUSION: The results of the present study demonstrate that saliva wetness testers are as useful as moisture-checking devices to examine dry mouth in patients with maxillary obturator prostheses.

Survival of microorganisms on complete dentures following ultrasonic cleaning combined with immersion in peroxide-based cleanser solution.

OBJECTIVES: To compare ultrasonic cleaning combined with immersion in a commercially available peroxide-based cleanser solution (Polident(®) ) with other denture cleaning methods, we examined the quantity of micro-organisms that survived on dentures before and after various cleaning methods. SUBJECTS AND METHODS: One hundred complete dentures belonging to 50 nursing home residents (mean age, 84.6 years) were randomly assigned to five groups according to the cleaning method employed: (A) immersion in Polident(®) solution alone, (B) brushing with water, (C) ultrasonic cleaning with water, (D) method (A) followed by method (B) and (E) ultrasonic cleaning combined with immersion in Polident(®) solution. Before and after the dentures had been cleaned, denture biofilm was collected from the mucosal surface of each lateral half of the examined dentures. The collected micro-organisms were cultured, presumptively identified by standard methods and quantified. Comparisons between the five cleaning methods were carried out using the Kruskal-Wallis test and Dunn's multiple comparisons test. RESULTS: The denture cleaning methods involving the use of Polident(®) solution (methods A, D and E) were significantly more effective at denture disinfection than the other methods (p < 0.05); in particular, the quantity of Candida spp. was lowest after method E (median, 0.00; significantly lower than those observed after methods A, B and C; p < 0.05). CONCLUSION: It was concluded that ultrasonic cleaning combined with immersion in a peroxide-based cleanser solution effectively reduces the quantity of micro-organisms surviving on dentures and is a suitable method for elderly individuals who find brushing their dentures difficult.

Changes in lip forms on three-dimensional images with alteration of lip support and/or occlusal vertical dimension in complete denture wearers.

PURPOSE: This study aimed to examine changes in the lip form, oral fissure form and vermilion height of complete denture wearers resulting from altered occlusal vertical dimension (OVD) and/or lip support. METHODS: Three-dimensional facial images of 10 edentulous patients (four males and six females) when wearing six experimental record blocks (ExpRBs) with varying OVD and/or lip support were analyzed. Analysis was performed using three landmarks on the mid-line (labrale superius (ls), stomion (sto), and labrale inferius (li)) and two landmarks on the oral fissure (at points 20mm right and left of the midline (r-OFP and l-OFP, respectively)). Curvature of the oral fissure (COF) in the frontal view was evaluated by calculating the difference between sto and the average of r-OFP and l-OFP (avrl-OFP). The vermilion height in the frontal view was calculated as the distance from sto to ls and li. In 10 subjects, comparison between standard ExpRB and test ExpRBs with altered OVD and/or lip support was performed by calculating differences between these data. RESULTS: The ls, sto, and li landmarks changed with alteration of OVD and/or lip support, whereas avrl-OFP changed vertically with alteration of lip support and anteroposteriorly with alteration of OVD and/or lip support. COF and vermilion height were affected by alterations in OVD and/or lip support. CONCLUSION: Deficient OVD with extensive lip support can curve the oral fissure form upward, and deficient OVD with deficient lip support can reduce the vermilion height.

Relationship between symptoms of dryness and moisture levels in patients with maxillofacial prostheses.

PURPOSE: This study aimed to examine the relationship between symptoms of dry mouth and the moisture levels in patients with maxillofacial prostheses. METHODS: Dry mouth of 30 patients with maxillofacial prostheses was examined by direct measurement of oral moisture and subjective symptoms of dry mouth were surveyed using Kakinoki's questionnaire. Oral moisture was measured five times at each of the lingual mucosa and the right and left buccal mucosa using Moisture Checker Mucus and the mean value was calculated. Using a value of 29% as a reference, patients were classified as normal when the moisture value was 29%, or more, or with dry mouth if the value was when less than 29%. RESULTS: The moisture levels of the patients with subjective symptoms of dry mouth were significantly lower than those of the patients without symptoms of dry mouth at each of the lingual and buccal mucosa. The moisture level of the lingual mucosa was significantly lower than that of buccal mucosa in the group reporting subjective symptoms of dry mouth, but not in those without symptoms. CONCLUSION: These results suggest that the symptom of dry mouth is corresponding to the moisture level and the moisture level of the lingual mucosa is associated with symptoms of dryness in patients with maxillofacial prosthesis.

Relationship between medical treatment and oral dryness diagnosed by oral moisture-checking device in patients with maxillofacial prostheses.

PURPOSE: This study aimed to examine the relationship between oral dryness and medical treatment (medication, radiotherapy) for patients with maxillofacial prostheses. METHODS: Sixteen patients with maxillofacial prostheses were examined according to the following procedure. For evaluating oral dryness, oral moisture was measured at the lingual mucosa and the right and left buccal mucosa using a Moisture Checker Mucus. The mean value of each measurement was recorded as the moisture value (%). A value of 29% was used as a reference value to divide patients into a normal group and an oral dryness group. Patients with a moisture value of more than 29% were classified as normal. The clinical histories of the patients (including their current medication use and radiotherapy history-dose of radiation and period after radiation) were surveyed from their clinical records. Patients rated themselves on their feelings for oral dryness using a faces scale. RESULTS: The moisture value was significantly lower in the oral dryness group than the normal group. There was a significant difference in moisture values between the number of patients with and without radiotherapy, but not patients with and without medications. The moisture value had a significant negative correlation with the dose of radiation and a positive one with the period after radiation. The score of faces scale showed a significant negative correlation with moisture value. CONCLUSION: The patients with maxillofacial prostheses who had undergone radiotherapy need moisture retention because of oral dryness depending on the dose of radiation and the period after radiation.