Evaluation of the pressure distribution and correlated factors affecting pressure on maxillary edentulous ridge impression

• Main Authors: Jia-Jang Sheu, 許家彰
• Other Authors: 王若松
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/12514070172640931443

碩士 === 國立臺灣大學 === 臨床牙醫學研究所 === 95 === Introduction: When fabricating a complete denture for an edentulous patient, impression of edentulous ridge is the key of success in initial stage. There are different concepts in which impression is taken under different conditions based on the different theories. The scholar of the different theory advocated that by altering the tray design and the selection of impression material, impressions of edentulous ridge can be taken under expected conditions to reach mucostatic, functional or selective pressure impressions; however, we need exact evidences for these clinical practice. Objectives: The purpose of this in vitro study was to evaluate the influence of ridge height and tray design on the impression pressure generated upon oral mucosa. Methods: Standardized maxillary edentulous resin models of 5 different alveolar ridge heights from 2 to 10mm with 2mm increment were made. On each model, 20 different individual resin trays were fabricated with a combination of 4 different relief space (1, 2, 3, 4mm thickness) and 5 different relief holes (0, 2, 4, 6, 8mm diameter). Polyether impressions were then performed 5 times with each individual tray on the corresponding model. The pressure change on alveolar mucosa of four regions: molar(A), incisor(B), premolar(C), and palate(D) were detected by pressure sensor and recorded with 10 Hz sampling frequency for 5 minutes. Initial and ending pressures were analyzed with multiple regression analysis. Results: The results revealed that the pressure was distinctively different at the four regions. The initial pressures were positively correlated with alveolar ridge regions B (FB) and ridge height(R), and they were negatively correlated with alveolar ridge regions D (FD), alveolar ridge regions A (FA), and relief space thickness (S) (P < 0.01). But they were rarely correlated with relief hole size (H); The ending pressures were positively correlated with alveolar ridge regions B (FB) and ridge height(R), and they were negatively correlated with alveolar ridge regions D (FD), alveolar ridge regions A (FA), relief space thickness (S), and relief hole size (H) (P < 0.01). The initial and ending pressures could be expressed by multiple regression analysis. Conclusions: The pressures during impression were obviously influenced by the alveolar ridge region, the height of alveolar ridge and tray designs including the thickness of relief space and the size of relief hole.