Table of Contents
- 1 How long can alginate impressions be stored?
- 2 How quickly and why should an irreversible hydrocolloid impression be poured?
- 3 How do you preserve alginate impressions?
- 4 What happens if an alginate impression is stored in water?
- 5 Should you pour the gypsum immediately after taking impression?
- 6 What is an irreversible hydrocolloid?
- 7 When do you use reversible hydrocolloid impression material?
- 8 What can an irreversible hydrocolloid be used for?
How long can alginate impressions be stored?
The results showed significant differences between the alginates; however, no differences in dimensional accuracy were found among the different storage times of alginate impression. Conclusions: It can be concluded that the alginate impressions can be stored for up to 5 days.
How quickly and why should an irreversible hydrocolloid impression be poured?
2, 12, 23, 24, 25Other researchers have stated that in order to achieve the best results, dental irreversible hydrocolloid impressions should be poured after 10 minutes to avoid distortion from initial expansion and elastic deformation, but prior to 1 hour to avoid distortion from irreversible hydrocolloid contraction …
How is a poured hydrocolloid impression stored?
Because it is not always possible to pour the impression immediately in routine clinical practice, all irreversible hydrocolloid materials studied could be stored in a zip-lock plastic bag for upto 1 h without any significant distortion.
What happens if you store the impression for after an hour before you pour the cast stone?
However, if you allow the impression material to remain in contact with the stone for more than a few hours, it becomes chalky, and as the alginate dries out, it becomes stiff and will tend to break off teeth as well. Bottom line: The casts should be removed, ideally, between 1-3 hours after pour-up.
How do you preserve alginate impressions?
For maximum accuracy alginate impressions should be poured up in the model material as soon as possible. If for some reason they cannot be prepared directly, they should be stored in 100 relative humidity in a plastic bag or wrapped in a damp (but not wringing-wet) paper towel.
What happens if an alginate impression is stored in water?
If an alginate impression is stored in water or in a soaked paper towel, the alginate will absorb the additional water and expand. This property is called: imbibition.
How do you store dental casts?
Keep the plastic liner closed and wrapped tightly when not in use or transfer bulk material to smaller, sealed lid containers. Stone or plaster bins: place only the amount used in a day and reload for the next day’s use. Use sealed containers in dental offices especially. Do not store opened powder in drawers.
How do you store alginate?
Should you pour the gypsum immediately after taking impression?
The impression should be poured immediately after mixing. Pouring the impression should be completed within the working time. The gypsum begins to crystallize at the end of the working stage. No further work can be carried out because fine details can no longer be accurately reproduced after setting begins.
What is an irreversible hydrocolloid?
A hydrosol of alginic acid whose physical state is changed by an irreversible chemical reaction, forming insoluble calcium alginate. This substance is called alginate or dental alginate. Alginate is used in dentistry as a primary impression material. Synonym: alginate.
Does alginate expire?
Properly stored at room temperature (73°F/ 23°C) in a low humidity environment (below 50% RH), these products have a shelf life of 18 months from date of manufacture in unopened containers.
How long keep dental records?
How long do we have to keep dental records? In general, clinical and financial records, as well as radiographs, consultation reports, and drug and lab prescriptions must be maintained for at least ten years after the date of the last entry in the patient’s record.
When do you use reversible hydrocolloid impression material?
These materials are temperature sensitive, changing from liquid to solid at different temperatures, so they are often used with special water-cooled trays in order to capture the most accurate impressions. Because of the reversible nature of these materials, models should be poured immediately after the impression is taken.
What can an irreversible hydrocolloid be used for?
Irreversible hydrocolloid can be used in preliminary impressions, provisional crown-and-bridge impressions, study models, opposing dentition impressions. Alginates are used for impressions in orthodontic models, sports mouth guards, and bleaching trays; and more.
When to add reversible materials to an impression?
Because of the reversible nature of these materials, models should be poured immediately after the impression is taken. These materials work well because of their natural hydrophilicity and the fact that the material does not need to be mixed prior to being added to the impression tray.
Which is the oldest dental impression material still in use?
Among the oldest dental impression materials still in use, reversible hydrocolloid impression materials are formulated with agar and effectively solidify from their liquid state to a solid gel state in the mouth to capture a highly accurate impression.