Pressure Characteristics of Maxillary and Mandibular Edentulous Impressions: An In-vitro Study

Abstract

Introduction: One major factor that determines the stability and retention of prosthesis is the amount of pressure produced during final impression. The aim of the present study was to assess the pressure changes created during impression process by relief space, escape holes, and different seating velocity on a simulated maxillary and mandibular edentulous arch using light body polyvinyl siloxane impression material. Methodology: The present study was done on a total of 54 trays: 27 maxillary and 27 mandibular. Each tray had a specific combination of escape hole, relief space, and seating velocity. Impression was taken with Aquasil (light body polyvinyl siloxane). The variables assessed were relief space, escape holes, and seating velocity. Area chosen for the maxillary arch was midpalatine raphe and the area chosen for the mandibular arch was anterior ridge. Results: We found that greater the amount of relief space given, lesser was the pressure generated. Similarly, greater the dimension of escape holes, lesser was the pressure generated; in case of seating velocity, greater the seating velocity, more pressure was generated. Conclusion: All three factors i.e. relief space, escape holes, and seating velocity had an effect on the pressures exerted on denture supporting tissues.

Keywords

• Escape holes, polyvinyl siloxane, pressure generation, relief space, ridge resorption, seating velocity.