Linear setting expansion of different gypsum products
RSBO (Impr.)
;
12(1): 61-67, Jan.-Mar. 2015.
Article
in English
| LILACS
| ID: lil-782786
ABSTRACT
Introduction:
Stone casts are used in dentistry to allow the confection of indirect restorations. Thus, gypsum dimensional stability is fundamental in order to achieve a precise fit between dental structure and restorative material.Objective:
The purpose of the present study was to evaluate the hygroscopic linear expansion of commercially available gypsum products. Material andmethods:
Fifteen dental stones were analyzed (4 type II, 5 type III, 4 type IV and 2 type V), with n = 5. One hundred grams of each gypsum product were mixed following the respective manufacturers' recommendations for powder/water ratio and poured into a V-shape mold, connected to an expansion-measuring device. The hygroscopic expansion was evaluated during 120 min and the collected data was converted into percentage and compared to initial dimensions of the specimen.Results:
All type II and V dental stones showed expansion values compatible to the ADA and ISO recommendations. Considering type III stones, only Rutenium 3 was compatible with the recommendations. For type IV, only Durone IV showed expansion values higher than that recommended by ADA, but lower than that of ISO recommendations.Conclusion:
The hygroscopic linear expansion of gypsum products should be periodically controlled in order to ensure their precision and reliability to dental practice.
Full text:
Available
Index:
LILACS (Americas)
Type of study:
Practice guideline
Language:
English
Journal:
RSBO (Impr.)
Journal subject:
Dentistry
Year:
2015
Type:
Article
Affiliation country:
Brazil
Institution/Affiliation country:
University of São Paulo/BR
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