Innovative two-part impression technique for an extensive maxillary defect

Patients reporting with large maxillary defects pose great difficulty in prosthodontic practice. After thorough history and clinical examination, prosthetic rehabilitation of these patients usually starts with an impression. In such cases conventional single step impression technique solely may not give the desired results. If the defect is of large size then impression making becomes difficult and complicated procedure. Therefore, conventional impression technique can be modified according to the needs and requirements. This report describes a modified and innovative technique of making impression in two parts, which can be withdrawn from mouth in two segments and easily reoriented outside the mouth

Disinfection of irreversible hydrocolloid impression material: effect on linear dimensional stability

The dental impressions contaminated with saliva and/or blood must be considered source of infection, with the potential of transmitting disease to the dentists, auxiliary personnel and laboratory technicians. The cross infection control measures must follow while handling these impressions or casts without compromising on their dimensional stability. The objective of this study was to evaluate the linear dimensional stability of irreversible hydrocolloid [alginate] when it is disinfected with 0.5% NaOCl by immersion and incorporation methods. This was Quasi Experimental study. One-hundred-seventeen [117] impressions were made out of which Fifty-seven [57] were not included in the study. Impressions were made by non-probability purposive sampling technique. Casts were made from the impressions. Measurements of the casts at three specific points were carried out using measurement guiding template through screw gauge and were recorded. In this study Sodium Hypochlorite 0.5% was used as disinfectant material for irreversible hydrocolloid. Immersion disinfection of irreversible hydrocolloid in 0.5% Sodium Hypochlorite showed statistically significant effect on its linear dimensional stability [p<0.05]. On the other hand, incorporation of Sodium Hypochlorite 0.5% in irreversible hydrocolloid as a water substitute was not practical, as it resulted in detachment of material from the impression tray. Disinfection of irreversible hydrocolloid by immersion method results in linear dimensional instability of the material and by incorporation method it is not possible