Enzymes as denture cleansers.

It was the purpose of the study to test the efficiency of dextranase, mutanase, and protease in removing denture plaque. The study group comprised 100 denture-wearers with denture stomatitis. The enzymes were dispensed as dissolvent tablets either in pure or in mixed preparations. Placebo tablets and Steradent, a commercial denture cleanser, were used as control tablets. The following parameters were studied: the amount of denture plaque, the degree of palatal erythema, and the concentration of yeast cells and inflammatory cells in mucosal and denture smears. The study was designed and carried out as a double-blind study. The dissolvent tablets containing the enzymes in mixed preparations were more effective than the tablets containing the pure enzymes, the placebo tablets, or the Steradent tablets. The beneficial effect of the mixed enzyme preparations included a significant reduction of the amount of denture plaque and an improvement of the clinical condition of the palatal mucosa.     

A 3-months''study of enzymes as denture cleansers

It was the purpose of the study to test the efficacy of dissolvent tablets containing mutanase and protease in removing denture plaque. The study group consisted of forty institutionalized geriatric denture wearers, who were assigned randomly into an enzyme group and a placebo group. Enzyme tablets and placebo for denture soaking were administered by the nurses. The dentures were immersed for 15 min once daily for three months. The amount of denture plaque, the clinical condition of the palatal mucosa, and the concentration of yeasts and bacteria in mucosal and denture smears were recorded before, during, and after the experimental period. The study was designed and carried out as a double-blind study. After denture soaking for six weeks a significant reduction of the amount of denture plaque and improvement of the clinical condition of the palatal mucosa was recorded. After denture soaking for twelve weeks the conditions had improved further when comparing the enzyme group with the placebo group.     

Reduction of formation of denture plaque by a protease (Alcalase)

The efficacy of a protease preparation (Alcalase, Novo, Denmark) in preventing accumulation of plaque on the fitting surface of complete upper dentures was examined in a double-blind study. Seventeen denture wearers with clinically healthy oral mucosae participated in the study. The protease was dispensed in dissolvent tablets containing 15, 30, 60, 100, 300, 500, or 1000 mg of the enzyme. Enzyme tablets or placebo tablets were dissolved in 150 ml water at 50 degrees C, and the dentures were soaked once daily for 15 min. Denture soaking was performed with or without brushing. The study consisted of 14 1-week periods. At the start of each period the dentures were cleaned by brushing until they showed no visible plaque after staining. At the end of each period plaque was stained and the dentures were photographed. The photographs were projected, and the percentage area of the fitting surface showing plaque deposits was scored with 10% intervals. Statistical analysis showed that there was a significant reduction of plaque scores with increasing enzyme concentration. The most marked reduction in plaque formation was seen when mechanical cleansing was combined with immersion in a 500-mg enzyme solution. At a concentration of 300 mg (or more) the enzyme immersion was as efficient as mechanical cleansing in preventing denture plaque accumulation.     

Denture plaque and palatal mucosa in denture stomatitis: scanning electron microscopic and microbiologic study

Denture plaque is an etiologic factor in denture stomatitis. In this study, denture and mucosa samples from nine patients were examined in the SEM and processed for microbiologic cultures. Denture plaque in patients with denture stomatitis showed a considerable thickness containing cocci, filaments, rods, yeasts, and desquamated epithelial cells. Some microorganisms were revealed in the connective tissue in one patient and phagocytizing polymorphonuclear leukocytes were found in the palatal mucosa of the patients with denture stomatitis.     

Chlorhexidine gel and Steradent employed in cleaning dentures.

It was the purpose of the study to test the efficacy of brushing with a 1% chlorhexidine gel or a commercial solution cleanser (Steradent) in preventing formation of plaque on the fitting surface of new dentures. The study group consisted of 74 denture wearers with denture stomatitis who were assigned randomly to one of four treatment groups, testing either the chlorhexidine gel, a placebo gel, Steradent, or a placebo solution. The experiment was started immediately after denture treatment was completed. The experimental period was 1 month. The amount of denture plaque, the clinical condition of the palatal mucosa, and the concentration of yeasts in mucosal and denture smears were recorded while the patients used their original dentures and after the experimental period. Plaque had formed on all new dentures but to a smaller extent in the groups testing the chlorhexidine gel or the placebo gel. The study does not provide any obvious evidence of a chemical effect of chlorhexidine gel or Steradent as a means to prevent formation of microbial plaque on the mucosal surface of maxillary complete dentures.     

Clinical effects of glazing denture acrylic resin bases using an ultraviolet curing method

Control of denture plaque accumulation is essential to obtain and maintain a healthy oral mucosa in denture wearers. The present study was designed to study the effect on denture plaque accumulation and denture stomatitis of coating the fitting denture surface by a glaze. Twenty-one subjects wearing complete dentures participated in the study. Glazing of the denture surface was performed using a Perma Cure System. Plaque accumulation was studied clinically and using a semiquantitative microbiologic technique. Plaque accumulation on the glazed and the non-glazed halves of the fitting denture surface was compared after 1 wk. There was significantly less plaque on the glazed half of the denture (P less than 0.001), and the calculated number of CFU of bacteria/cm2 was significantly lower from the test area of the glazed half than from the test area of the non-glazed half of the denture (P less than 0.001). When the patients were re-examined 1 month after the entire fitting denture surface had been glazed plaque scores, yeast scores and number of CFU of bacteria/cm2 were not significantly different from those observed before glazing. There was a reduction of the erythema of the palatal mucosa in 14/19 patients with denture-induced stomatitis. The study indicates that coating of the fitting denture surface by a glaze may be a means to improve denture cleanliness; however, the present glazing system should be further developed to produce a more uniform glazing.     

Clinical effects of glazing denture acrylic resin bases using an ultraviolet curing method

Abstract – Control of denture plaque accumulation is essential to obtain and maintain a healthy oral mucosa in denture wearers. The present study was designed to study the effect on denture plaque accumulation and denture stomatitis of coating the fitting denture surface by a glaze. Twenty-one subjects wearing complete dentures participated in the study. Glazing of the denture surface was performed using a Perma Cure System. Plaque accumulation was studied clinically and using a semiquantitative microbiologic technique. Plaque accumulation on the glazed and the non-glazed halves of the fitting denture surface was compared after 1 wk. There was significantly less plaque on the glazed half of the denture ( P <0.001), and the calculated number of CFU of bacteria/cm² was significantly lower from the test area of the glazed half than from the test area, of the non-glazed half of the denture ( P <0.001). When the patients were reexamined 1 month after the entire fitting denture surface bad been glazed plaque scores, yeast scores and number of CFU of bacteria/cm² were not significantly different from those observed before glazing. There was a reduction of the erythema of the palatal mucosa in 14/19 patients with denture-induced stomatitis. The study indicates that coating of the fitting denture surface by a glaze may be a means to improve denture cleanliness; however, the present glazing system should be further developed to produce a more uniform glazing.     

Assessment of denture plaque pH in subjects with and without denture stomatitis

abstract — To evaluate the "resting" pH and induced pH changes in denture plaque, soft deposits were collected from the fitting surface of the denture, pooled and suspended in water. Plaque pH was determined with microelectrode equipment before and after mouth rinsing with a sucrose solution. A characteristic level in the "resting" pH of denture plaque was found in most of 12 subjects tested. pH values below the baseline level were recorded for more than 2 h after a rinse. The pH depressions were more pronounced in maxillary than in mandibular plaque. Further, the pH minima tended to be lower in subjects with denture stomatitis than in. controls. No clear relationship could be established between the "resting" pH and the concentration of Candida hyphae in denture smears or palatal inflammation.     

Status and treatment of denture stomatitis patients: a 1-year follow-up study

Abstract – The material comprised 48 patients, 19 exhibiting atropiiic and 29 hyperplastic denture stomatitis. Twenty-seven patients with healthy mucosa served as a reference group. Past history, resilience of the mucosa, denture function and scores of palatal erythema, plaque and yeasts were recorded. The therapeutic program included new dentures, surgical and nystatin treatment, hygienic instruction and nutritional advice. The results concerning past history showed significantly more smokers, more patients with recurrent urinary tract infections in combination with prolonged antibiotic therapy, and more patients wearing their dentures at night in the denture stomatitis group. Nystatin treatment did not affect the healing of palatal erythema evaluated after 1 year. The treatment program evaluated after 1 year resuhed in complete healing of the rnucosa in 50% of patients. The remaining 50% had persisting erythema of varying intensity. The unhealed cases showed significantly more yeasts and. plaque on the denture base compared to the healed patients and the reference group. An evaluation of factors common to failure of healing is presented.     

Denture cleansing: A comparison of two methods

A paste brushing method (Complete) and soaking in either of two denture cleanser tablet solutions (Efferdent or Polident) were compared for denture cleansing effectiveness as measured by plaque level. The 12-week product use period with weekly evaluations allowed an assessment of plaque reaccumulation on the denture surface as well as the effect of a single cleansing event and the contribution of bleaching to the total plaque-cleansing activity.The paste/brushing method was consistently the more effective procedure for removal of denture plaque. However, the bleaching effects of the effervescent tablets could be useful in an overall denture hygiene program.     

Carboxylic acids and pH of denture plaque in patients with denture stomatitis

Denture stomatitis (DS) is the commonest form of oral Candida infection. Although it has been suggested that the acidic conditions prevailing beneath maxillary dentures may potentiate palatal inflammation associated with DS, little is known about the pH and carboxylic acids of denture plaque in subjects with and without the disease. Therefore, qualitative and quantitative analyses of short-chain carboxylic acids and pH of maxillary denture plaque of ten patients and nine controls were performed. Gram-stained smears of plaque revealed numerous yeasts in the DS plaque while yeasts were absent in control plaque. Acetate, lactate, propionate, succinate, formate and pyruvate were present in descending order of concentration in all plaque samples. DS plaque was more acidic and contained significantly lower concentrations of lactate ions than control plaque. These results imply that the carboxylic acids produced by the microflora of denture plaque may be aetiologically involved in the pathogenesis of denture stomatitis.     

Clinico-pathological study on denture stomatitis

The clinical and pathological study was performed in order to determine the histopathological and cytoimmunological characteristics of denture stomatitis. All specimens were biopsy materials from seventeen patients with denture stomatitis. Normal palatal mucosae from ten patients served as the control. In addition to the usual staining methods, naphtol AS-D chloroacetate esterase stain and peroxidase-antiperoxidase method were used to detect mast cells and plasma cells. Denture stomatitis could be divided into atrophic and hyperplastic types. The former showed a smooth and atrophic mucosa. The latter showed a large number of exophytic projections which were composed of marked acanthosis and submucosal fibrosis, and was further subdivided into granular and papillary subtype according to the size of projections. In the present study, there were six cases of the atrophic type, and eleven cases of the hyperplastic type (consisting of seven granular and four papillary subtypes). The hyperplastic type was more frequently observed in patients with partial dentures compared with complete dentures and was associated frequently with ill fitting of the denture base as well as agglutination of denture plaque. Cytoimmunological study revealed that there was a pronounced increase of plasma cells, especially IgG- and IgA-producing cells, and a moderate increase of lymphocytes as well as mast cells in both types of denture stomatitis. Mast cells were always noted in the area with marked plasma cell infiltration, suggesting an intimate relation between both cells. These findings suggest that the immunological reactions play some role in the pathogenesis of denture stomatitis.     

Quantitative relationship between yeasts and bacteria in denture-induced stomatitis

Abstract – Quantitative cultural studies of yeasts and bacteria were made from 7-day-old denture plaque accumulated on pieces of self-adhesive tape stuck on the fitting surface of the maxillary denture in 17 edentulous subjects with healthy oral mucosa and in 27 patients affected with denture-induced stomatitis. Significantly higher numbers of yeasts and bacteria were cultured in the stomatitis patients than in the controls. This indicates that the rate of plaque formation is increased in patients with denture-induced stomatitis. Yeasts usually constituted less than 1% of the anaerobic bacterial counts, but the percentage of yeasts was significantly higher in the stomatitis patients than in the controls. There was a significant correlation between initially high yeast counts and improvement of the clinical condition of the palatal mucosa following antimycotic treatment. In some patients only bacteria were grown and antimycotic treatment had no effect. The study supported the contention that yeast antigens and toxins of denture plaque are significant factors in initiation and maintenance of denture-induced stomatitis. However, bacteria may also be involved as pathogens.     

The Langerhans cell density of palatal epithelium in denture and non-denture wearers, as correlated with other parameters of the palatal mucosa

A quantitative histological investigation was carried out on biopsy specimens taken from patients suffering from denture sore mouth. The results were compared with those obtained in investigations on denture and non-denture wearers. The sections were studied by standardized quantitative morphometric methods. After 4 years the denture bearing palatal epithelium from both groups, normal denture wearers and the patients suffering from denture sore mouth did not show changes in mean thickness of the epithelium as compared with the controls. The mitotic index in denture bearing epithelium from patients suffering from denture sore mouth was three times lower than in the epithelium of the normal denture wearers. The number of Langerhans cells correlated with the mitotic indices of the group of denture wearers and non-denture wearers. The group of denture sore mouth patients showing a low mitotic index showed a high number of Langerhans cells in their palatal epithelium. The three groups of patients investigated did not show differences in density of mast cells in the lamina propria of their palatal epithelium.     

Plaque accumulation following the wearing of different types of removable partial dentures

A group of forty-five patients took part in a study to assess the effects of wearing partial dentures upon the accumulation of plaque in the mouth in the absence of oral hygiene. The wearing of a partial denture resulted in a significant increase in plaque accumulation and this increase was the result of a significant increase in both buccal and lingual plaque. Furthermore in a group of ten patients a small, but significant, increase in plaque occurred in the opposing arch during the wearing of the dentures. The accumulation of plaque on the buccal aspect of the teeth appeared unrelated to the type of denture worn. However, significantly more plaque accumulated on the lingual aspect of all the teeth in those patients wearing lower plate dentures as opposed to lower bar dentures. In the 3 day study periods only a small increase in plaque occurred on the palatal aspect of the upper anterior teeth not covered by any part of the partial denture and no significant increase occurred on the lingual aspect of the lower anterior teeth not covered by the partial denture. A highly significant increase occurred on the lingual aspect of lower anterior teeth covered by the lingual plate of the partial denture. Overall the wearing of a denture day and night resulted in more plaque accumulation compared with day only wearing of dentures. However considering the denture types this significant increase was not apparent in the lower plate dentures. The results provide further evidence of the potentially adverse effect partial dentures may have upon the supporting structures of the teeth when oral hygiene procedures carried out by the patient are inadequate.     

上颌钛制腭托全口义齿临床应用的回顾性研究

目的：探讨纯钛作为全口义齿上颌腭托材料在口腔内长期应用后的临床效果。方法：选择由同一全口义齿专家多次镶配全口义齿的患者11例，最后一副义齿为钛制上颌腭托，进行满意度问卷调查及义齿检查。结果：采用传统PMMA制作的全口义齿的重做原因，主要是上颌基托折裂(72．7％)，其次为不舒适(27．3％)和固位差(27．3％)，改用钛制腭托义齿后，平均戴用2．95年未出现折裂；72．8％的患者认为钛制腭托义齿优于PMMA腭托义齿，主要表现在异物感小，固位好，舒适，质轻，可以改善口干症状，18．2％的患者认为两种义齿使用效果不存在明显差别。钛制义齿磨光面45．4％出现色素沉着，27．2％颜色变暗。腭部粘膜未见明显炎症。在咀嚼功能、发苦、冷热刺激的敏感性及味觉方面两种材料义齿没有明显差别。结论：全口义齿上颌腭托采用纯钛制作，其抗折性能、舒适性优于传统PMMA，但长期应用后，部分腭托磨光面出现色素沉着及颜色变暗，对固位及适合性的影响因受个人因素、义齿制作质量的影响，有待进一步研究。     

Quantitative relationship between yeast and bacteria in denture-induced stomatitis

Quantitative cultural studies of yeasts and bacteria were made from 7-day-old denture plaque accumulate on pieces of self-adhesive tape stuck on the fitting surface of the maxillary denture in 17 edentulous subjects with healthy oral mucosa and in 27 patients affected with denture-induced stomatitis. Significantly higher numbers of yeasts and bacteria were cultured in the stomatitis patients than in the controls. This indicates that the rate of plaque formation is increased in patients with denture-induced stomatitis. Yeasts usually constituted less than 1% of the anaerobic bacterial counts, but the percentage of yeasts was significantly higher in the stomatitis patients than in the controls. There was a significant correlation between initially higher yeast counts and improvement of the clinical condition of the palatal mucosa following antimycotic treatment. In some patients only bacteria were grown and antimycotic treatment had no effect. The study supported the contention that yeast antigens and toxins of denture plaque are significant factors in initiation and maintenance of denture-induced stomatitis. However, bacteria may also be involved as pathogens.     

Assessment of denture plaque pH in subjects with and without denture stomatitis.

To evaluate the "resting" pH and induced pH changes in denture plaque, soft deposits were collected from the fitting surface of the denture, pooled and suspended in water. Plaque pH was determined with microelectrode equipment before and after mouth rinsing with a sucrose solution. A characteristic level in the "resting" pH of denture plaque was found in most of 12 subjects tested. pH values below the baseline level were recorded for more than 2 h after a rinse. The pH depressions were more pronounced in maxillary than in mandibular plaque. Further, the pH minima tended to be lower in subjects with denture stomatitis than in controls. No clear relationship could be established between the "resting" pH and the concentration of Candida hyphae in denture smears or palatal inflammation.     

不同材质的义齿基托对修复效果影响的分析

目的：应用复制义齿技术制作不同材质基托,研究义齿基托材料对义齿功能发挥的影响。方法选取符合纳入标准的多数牙缺失的患者,采用复制义齿技术制作不同基托材质(纯钛、钴铬合金和树脂基托)的义齿各10件。分别对3组义齿修复体进行重量等指标的比较观察,评价固位力等初戴效果。结果经过实际测量,在义齿重量方面,上颌的纯钛组与钴铬组有明显差异（P<0.05）。从患者评价方面,初戴时大多数患者感觉纯钛组义齿异物感小,固位好,质轻;金属基托从异物感和语言方面似乎更适应患者的心理要求。结论由于解剖位置和金属材料特性的原因,口腔修复材料选择时需要考虑义齿的修复效果,并不完全取决于材料的密度。     

复制义齿技术在研究全口义齿语音功能中的应用

目的：探讨应用复制义齿技术制作全口义齿,并分析初戴前后义齿基托对语音功能的影响。方法：选取符合纳入标准的患者,采用复制义齿技术基托置换的方法制作全口义齿,以患者主观自评和客观的汉语语音清晰度方法,分别测试3种基托全口义齿在初戴前、后的语音功能。结果：应用复制义齿技术可以减少影响研究义齿发音的因素;3组义齿初戴时,语音清晰程度统计分析结果,塑胶基托与金属基托间差异有统计学意义（P〈0.05）,钴铬和纯钛基托两组间无明显差异。结论：义齿基托厚度较基托材质对患者语音功能的影响更大,患者的主观感觉与实际语音功能恢复有时并不一致。