Complete Mucostatic Impression: A New Attempt

Digital denture with mucostatic base and functional borders: A cast-free digital technique

Digital complete dentures fabricated using a mucostatic impression, like intraoral scans, are desirable for their beneficial effect on long-term residual ridge stability but may have less retention than those fabricated with a mucocompressive impression. Border molding procedure may improve initial retention, thus favoring adaptation to new dentures, especially in cases where neuromuscular dysfunctions may diminish the patient's ability to cope with adapting to existing motor patterns or learn new ones. However, a mucocompressive impression may cause higher residual ridge resorption, thus resulting in a retention decrease over time. A desirable combination would be a digital denture with a mucostatic intaglio surface obtained from intraoral scans and functional borders. A cast-free digital workflow for that is demonstrated in this technical report.

Digital beading for a CAD-CAM framework for an implant-supported overdenture: A dental technique

The analog technique of making bead lines for a metal superstructure framework for the maxillary implant-supported overdenture is created by scribing shallow grooves on the surface of a definitive gypsum cast. This report describes a digital technique that uses computer-aided design and computer-aided manufacturing technology to make dental bead lines on an intraoral impression without using the gypsum cast.

Microstrain Analysis of Selective Pressure Techniques for Mandibular Complete Denture Impression: An In Vivo Study

Aim

The present in vivo study was undertaken for microstrain analysis of the selective pressure impression technique using strain gauges in mandibular complete denture impression.

Methodology

Ten completely edentulous patients undergoing complete denture treatment were selected for the study. For each patient, mandibular casts were made, and two custom trays were fabricated on the mandibular cast. These mandibular trays were divided into two groups: those with mandibular impressions made in the custom tray with the use of a spacer (MST) and those without a spacer (MWS). For each patient, a primary impression was made by using an impression compound. After that, the primary cast was obtained, and the custom tray was fabricated by using auto polymerizing resin. Then strain gauges were attached to the particular areas of the tray. The customized tray with zinc oxide eugenol impression material was seated in the patient's mouth for the final impression. The strain produced during impression making at different areas was recorded by a multi-channel (six) strain amplifier and data logger (8-channel digital strain indicator NIC, Jaipur, India). The data obtained were subjected to statistical analysis using an independent t-test (for quantitative data within two groups). The level of significance was set at p=0.05 (p<0.05-significant, p<0.01-highly significant, p<0.0001-very highly significant).

Results

The comparison of the percentage of microstrain produced at the relief area with and without spacer tray design showed a statistically significant (p=0.001) result with a greater number of percentages of microstrain among those without spacers (94.19) than with spacer (72.09) tray design.

Conclusion

The use of a tray with relief for selective pressure impression of an edentulous mandible resulted in a desirable pressure distribution at the alveolar crests and buccal shelves.

Custom double tray for a special impression technique for flabby maxillary residual ridge: Case report

The construction of a removable dental prosthesis for patients with compromised residual alveolar ridges is a challenge for prosthodontists. Flabby anterior ridges and hypermobile tissues in completely edentulous arches require special considerations during prosthetic management, especially when natural dentations remain on the opposite side. Previous studies have revealed that the displacement of flabby tissue can be reduced during impressions by controlling the applied forces via changes in factors such as the tray design, scraping of impression trays, impression material, window technique, and seating velocity of the impressions. However, there may still be some forces applied during impression or there is no even space because there are no trays supporting the vinyl polysiloxane (VPS) impression material in the open window area. Using a custom double tray with even gap between these trays and injecting light body impression material may eliminate these forces and provide accuracy due to even space for the impression material. This article is a clinical report of a patient who presented with an anterior flabby maxillary edentulous ridge opposing the remaining anterior natural teeth. A custom double tray was fabricated using the principle of the window technique. The gap between the double trays allows mucostatic impressions of flabby ridge tissue to be made with accuracy. The maxillary single denture, which was made with a custom double tray, satisfied the patient.

Management of the flabby ridge using a modified window technique and polyvinylsiloxane impression material

Flabby ridge is a common clinical finding affecting the alveolar ridges of the mandibular or maxillary arches. The anterior region of maxilla is the most affected area in edentulous patients. Dentures on flabby ridges have compromised stability, support, and retention unless adequate measures for its management are employed. Methods applied for flabby ridge management, include surgical removal and augmentation, special impression techniques, balanced distribution of occlusal loads and implant therapy. Special impressions often involve window technique for static impression of flabby area, which present multiple challenges. The purpose of this technique report is to present a modified window technique for the impression of anterior maxillary flabby tissues for improved and controlled application of polyvinylsiloxane impression material that are routinely available in dental practice.

Functional Impressions in Complete Denture and Overdenture Treatment

Tooth loss can cause loss of occlusal, masticatory, esthetic, physiognomic, phonetic and psychosocial function of patients. The most frequently used treatment method of completely edentulous patients and patients with a small number of remaining teeth are complete dentures or overdentures. One of the most important clinical and laboratory procedures in their fabrication is functional impression taking. The aim of this paper was to present procedures of taking functional impressions in fabrication of complete dentures and overdentures, using standardized techniques and materials. An accurate functional impression together with other correctly performed clinical and laboratory procedures ensure good retention and stability of dentures, which is a precondition for restoring patients' lost functions.

Management of excessive movable tissue: a modified impression technique

Excessive movable tissue is a challenge in complete denture prosthetics. A modified impression technique is presented with polyvinyl siloxane impression material and a custom tray with relief areas and perforations in the area of the excessive movable tissue.