Retention Of Maxillary Denture Research Articles

Measurement of oral status and treatment need among subjects with dental prostheses: Are the measures less reliable than the prostheses? Part I: Oral status in removable prosthodontics

Indices used to measure the oral status of removable dental prostheses generally do not conform to criteria essential to high-quality measures. Existing indices fail to meet accepted standards of reliability and validity, and most lack specified training protocols, use ambiguous terminology, are limited to nominal, ordinal, or dichotomous level data, and require high levels of observer inference. As a result it is virtually impossible to compare one study with another, to combine data from more than one study to broaden the results obtained, and even to collect longitudinal data without being able to rule out examiner drift. More successful measures, in particular for vertical dimension of occlusion, maxillary denture retention, and arch size and shape, hold promise for future developments in research data collection and quality assessment. These improvements, combined with a growing awareness of the importance of measuring nondental factors, should lead to more reliable, valid measures of need for treatment.

上顎総義歯の床下における気圧の動態 Ｉ 維持力との関係

Dynamics of atmospheric pressure under the maxillary complete denture, and their relations with the denture retention influenced by the factors such as the denture seating force, the saliva viscosity and the postdamming, were investigated on the simulation models. The following results were obtained. 1. The atmospheric pressure under the denture became higher than the external one by the denture insertion, and increased during the denture seating, and decreased by the removing force of denture and furthermore became lower than external one by continuous application of its force, and at all became equal to the external one when the denture separated from the basal seat. 2. Greater seating force brought about greater positive pressure and less negative pressure. 3. Higher viscosity of saliva and the postdamming brought about greater positive and negative pressures. 4. Both of greater seating force and higher viscosity of saliva brought about greater retentive force. 5. The postdamming was useful for the maxillary posterior border seal. 6. The atmospheric pressure under the denture base seems not to relate directly to the maxillary denture retention in the static condition but to reveal the status of peripheral seal.

Clinical evaluation of complete denture therapy: Examiner consistency

Criteria were developed to clinically evaluate denture base stability and retention. Six completely edentulous subjects participated in the study. Each patient was treated with two sets of complete dentures. Six prosthodontists who were not involved in the patients' treatment evaluated the stability and retention of each denture at the delivery appointment and weekly for the following 2 weeks by means of criteria in a standardized form. Evaluation of stability and retention for maxillary and mandibular complete dentures worn during weeks 1 and 2 were compared with the evaluations made at the delivery appointment for each denture. In tabulation of the data, the criteria considered reliable were mandibular denture retention, maxillary denture retention evaluated unilaterally, and maxillary denture stability. In each category most examiners rated the judgments the same or better when compared with the delivery appointment data for each patient.

The role of saliva in retention of maxillary complete dentures

In this study maxillary denture retention was influenced by the salivary volume between the denture base and the mucous membrane. An optimum intervening salivary volume, at which the greatest retention was developed, was also observed. It was observed from determination of electric resistance of palatal mucous membrane that inward and outward flow of intervening saliva was greater in the denture with poor retention than in the one with good retention. Moreover, when the salivary volume between the denture base and mucous membrane was optimum the salivary flow under the denture was minimum.