The influence of dentures on nasalance values in speech.

OBJECTIVE: The purpose of this study was to investigate the effects of maxillary dentures on nasalance values in normal elderly individuals. DESIGN: A three-factor within-subjects experimental design was employed to analyze the nasalance scores obtained. PARTICIPANTS: Twenty English-speaking women aged 61 to 81 years, who wore complete maxillary dentures, participated in the study. INTERVENTION: A Nasometer was used to collect nasalance data. Participants read three standard passages aloud, three times each, in two conditions: with and without their maxillary dentures. RESULTS: Results revealed that nasalance values were significantly lower with the maxillary dentures removed (p<.01), although the difference in nasalance between the two denture conditions averaged no more than 2%. Nasalance scores obtained both with and without maxillary dentures fell within one standard deviation of the mean for a reference group of comparably aged English-speaking women. CONCLUSIONS: The results suggest that the existing collection of normal reference data for nasalance may be safely used for elderly individuals regardless of their status with respect to natural or prosthetic maxillary dentition.     

The impact of falling rates of edentulism

PURPOSE: The aim of this study was to investigate the impact of both population age changes and falling edentulism rate on the denture market in three European countries. MATERIALS AND METHODS: Detailed information on the rate of edentulism for only three European countries (Finland, Sweden, and the UK) was available. For the UK and Sweden, published predicted rates of edentulism for the future decades were used, whereas predictions for Finland were computed using published edentulism rates. Edentulousness in one jaw was also predicted and included in the computation. Demographic projections were taken from government agency websites. RESULTS: The denture market will decrease in the three countries. Sweden, where edentulism is already low, will experience the largest percentage decrease (60%) over 20 years, but, in absolute number, the change will be of smaller magnitude than that in the UK and Finland. The range of projections for Finland was large, reflecting the difficulty of predicting trends with incomplete information. Within the limitations of this study's design, the impact of population age changes will not increase the denture market in Europe, even with the most pessimistic projections for edentulism rate. CONCLUSION: The complete denture market in Europe will fall despite changing age demographics. The falling rates are large enough to markedly affect future patterns of treatment provision and training.     

Rehabilitation of maxillary edentulism with implant-supported milled-bar prostheses

Implantology has allowed more options for rehabilitation of complete and partially edentulous patients. The professional should describe all possible alternatives to the patient, addressing all the positive and negative aspects of each possibility, such as treatment time, complexity of surgical procedures, and the final cost. The patient should select the best cost-benefit relationship because fixed prostheses are often not the option of choice for the patient. The aim of this article is to present one possible treatment option for the completely edentulous patient by use of implants to support and retain a removable complete or partial prosthesis. The clinical situations were rehabilitated by the use of a milled bar screwed to the implants to support a removable prosthesis with attachments and a milled metallic groove, which provide many advantages to the patient.     

Investigation of preferred viscosity of irreversible hydrocolloid on preliminary impression for edentulism

This study aims to investigate the preferred viscosity of irreversible hydrocolloid used in the preliminary impression for edentulism. Thirteen modalities of irreversible hydrocolloid were prepared by changing the W/P ratio. Discrimination test for the preferred viscosity was performed on 11 prosthodontists (10.4+/-5.3 years of prosthetic experience). The parameter of discrimination test (P%) was calculated as the ratio of the number of adequate tests to the total number of tests. The P% and apparent viscosity coefficient (eta a) values measured by rheometer demonstrated good correlation (Y = -35.8X2 + 118.4X - 22.8, r=0.86, p<0.01). Prosthodontists could judge the preferred viscosity based on their clinical experiences. On the preliminary impression for edentulism, the preferred viscosity demonstrated in vitro using a polyurethane maxilla model was 1.21 x 10(3) Pa x s.     

The aesthetic and functional restoration in the case of partial edentulism in young patients

The absence of teeth in youths can be due to congenital absence, traumas, caries and periodontitis. The loss of a tooth in growing patients can cause both aesthetic-functional and psychological problems, particularly if the teeth of the anterior region are involved. When there is the loss of a dental element in a teenager it is necessary to provide a quick suitable therapeutic solution, which will be different in comparison to an adult because of the changes related to the growth of the maxillary bones. The aim of this paper is the analysis of the several therapies which can be carried out on young patients with partial edentulism, paying particular attention to the conditions and the indications which allow an implant prosthesis restoration.     

附着体在末端游离缺损中的应用和基础研究

末端游离缺损修复一直是修复界研究的热点，随着新技术、新材料的不断出现，附着体在口腔修复中的应用正不断深入，它不仅增进美观，改善基牙的应力分布，提高咀嚼效能，还使牙列缺损的修复多样化。本文就附着体在末端游离缺损中的应用 基础研究作一综述。     

Influence of mandibular free-end partial edentulism on the force exerted on maxillary anterior teeth

PurposeThe purpose of this study was to determine the influence of mandibular free-end partial edentulism and the wearing of removable partial dentures in the partially edentulous area on the force exerted on maxillary anterior teeth.MethodsA commercially available jaw model with exchangeable teeth was used. Seven experimental conditions of mandibular free-end edentulism were set up and a distal extension removable partial denture to replace missing posterior teeth was fabricated. Strain gauges were attached to the root surface of the maxillary left central incisor, canine, first premolar and first molar, and the force exerted on them was calculated based on the calibration coefficient. An occlusal load of 49 N was applied and the forces were compared with the Kruskal–Wallis test (P < 0.05).ResultsThe force exerted on the maxillary anterior teeth increased significantly as the number of remaining teeth decreased. The force exerted on the maxillary anterior teeth decreased significantly with use of a removable partial denture.ConclusionsWhen the number of remaining teeth decreases in mandibular free-end partial edentulism, the burden on the maxillary anterior teeth increases. Our findings suggest that for patients with mandibular free-end partial edentulism, wearing a removable partial denture is effective in preserving the remaining teeth by reducing excessive stress.     

The influence of design and production on the structural integrity of tensile test specimens and stated values for mechanical properties

Two sizes of tensile test specimens were produced, the smaller of them by several techniques each incorporating a particular casting variable. All castings were subsequently subjected to radiographic evaluation and mechanical testing. An attempt has been made to relate the application of each variable to the degree of metal integrity produced in the specimens and ultimately to mechanical behaviour.     

Association of edentulism and diet and nutrition in US adults

Dental status and its relationship to diet and nutritional status have been little explored. In this study of a representative sample of the US civilian, non-institutionalized population (NHANES III), we predicted that the intake of nutritious foods, dietary fiber, and levels of biochemical analytes would be lower, even after adjusting for potential social and behavioral factors, among those who were edentulous and wore complete dentures than for those who had all their natural teeth. Multivariate analyses indicated that intake of carrots and tossed salads among denture-wearers was, respectively, 2.1 and 1.5 times less than for the fully dentate (p < 0.0001), and dietary fiber intake was 1.2 times less (p < 0.05). Serum levels of beta carotene (9.8 microg/dL), folate (4.7 ng/dL), and vitamin C (0.87 mg/dL) were also lower among denture-wearers (p < 0.05). Intakes of some nutrient-rich foods and beta carotene, folate, and vitamin C serum levels were significantly lower in denture-wearers.