ABSTRACT
Aim: Several new irreversible hydrocolloid formulations have recently become available with claims of an improved dimensional stability by the manufacturers. The aim of this study was to evaluate the accuracy of casts made from alginate impression materials poured immediately and after specific storage periods. Methods and Materials: Three alginates were tested Zelgan (Dental Products of India), DMC Algitex (Dental manufacturing & marketing Company) and A1 Alginate (occlusion products of India). A special stainless steel die representing a crown preparation was used to obtain impressions. These impressions were poured at different time intervals i.e immediately after a lapse of 5 minutes, 15 minutes, 30 minutes & 1 hour. Impressions were stored in a three different environments i.e. Air, water & 100% humidity. The casts were made & data were analyzed. Results: The dimensional stability of the alginate impressions was both material & time dependent. Conclusion: The dimensional stability of the alginate impressions is influenced by the selected materials and the storage time. An atmosphere of 100% humidity appears to be best storage medium. Clinical Significance: Alginate impressions should generally be poured immediately . Longer the period of storage more significant dimensional changes were observed.
ABSTRACT
Rehabilitation of hemimaxillectomy patients can be challenging. The most common prosthetic treatment problem with such patients is, getting adequate retention, stability and support. The size and location of the defect usually influences the amount of impairment and difficulty in prosthetic rehabilitation. Obturator prosthesis is commonly used as an effective means for rehabilitating hemimaxillectomy cases. In cases of maxillary defect, obtaining satisfactory retention, stability & biocompatibility in the definitive obturator prosthesis can be elusive. Resilient denture materials are extremely useful in retaining the prosthesis, which obturates the maxillary defects. This clinical report describes making of flexible obturator prosthesis with modified buccal flange on unresected side as a means of indirect retention. This approach provides excellent mouldability, light weight & strength of the prosthesis to increase the retention, stability and comfort.