A. Inadequate mixing
B. Air bubbles
C. Too rapid polymerization
D. Incomplete polymerization caused by premature removal from mouth
Related Mcqs:
- Rough and irregular surface produced on the impression is because of ?
A. Improper application of pressure during impression making
B. Air incorporated during mixing
C. Too rapid polymerization
D. Presence of moisture in impression area - Rough and irregular surface produced on the impression is because of_______________?
A. Air incorporated during mixing
B. Improper application of pressure during impression making
C. Presence of excessive saliva in impression area
D. Due to improper ratio of polymer and monomer - The American dental association (ADA) specification number for non-aqueous elastomeric dental impression material is______________?
A. 19
B. 20
C. 21
D. 26 - Which of the following is not true about elastomeric impression ?
A. Single mix material have higher viscosity
B. Shear thinning is related to viscosity of non phase impression material
C. Improper mixing of material can cause permanent deformation of impression
D. Putty – wash technique of impression reduces dimensional change of setting - Dimensional stability of elastomeric impression material can be given in descending order as_____________?
A. Polysulphide > polyether > Condensation silicone > Addition silicone
B. polyether > Condensation silicone > Polysulphide > Addition silicone
C. Addition silicone > polyether > Polysulphide > Condensation silicone
D. Addition silicone> Condensation silicone > Polysulphide > polyether - Which of the following best describes the working time of elastomeric impression material ?
A. After the start of appearing elastic properties of impression material
B. Just after the start of appearing elastic properties of impression material
C. Just before the start of appearing elastic properties of impression material
D. Loss of luster of impression material - What is the minimum thickness of the elastomeric impression material for an accurate impression_______________?
A. 2 mm
B. 2-4 mm
C. Greater than 3 mm
D. Maximum in the area of operation - Alginate impression material is similar to Agar-agar impression material in the following respect________________?
A. Gelation increase in both on increase in temperature
B. Mixing time is increased to reduce the setting time
C. Deformation during removal of impression occurs due to distortion of gel fibers
D. Both can be re-used for fresh impressions - Best impression material to be used for securing impression after crown preparation_______________?
A. Alginate
B. Agar
C. Elastome
D. Zno paste - Agar impression materials differ from alginate impression materials in that the former sets by_______________?
A. Mechanical action of saliva
B. Physical change
C. Evolution
D. Chemical change
