European Journal of Prosthodontics and Restorative Dentistry
- Cover Date:
- March 2006
- Print ISSN:
- 0965-7452
- Vol:
- 14
- Issue:
- 1
Film thickness and rheological properties of luting agents for crown cementation
Abstract - The ï¬lm thickness and rheological properties [viscosity and tan δ], of different resin based crown and bridge luting agents, including Panavia 21, Superbond, All Bond C&B Cement, Variolink were compared with zinc phosphate cement. A modiï¬cation of the method in ISO 9917 (1991) and a controlled stress rheometer were used to monitor the changes in the ï¬lm thickness and rheological properties respectively. For each material, the ï¬lm thickness and rheological characteristics were determined at 60s after start of mixing and then made at regular intervals until immediately before the material was set. For the initial ï¬lm thickness, the difference among the values for Varionk, Superbond and zinc phosphate cement was not signiï¬cant (P>0.05), and less than 25µm. The values for All Bond C&B Cement and Panavia 21 were at least twice that of the other materials tested. All Bond C&B Cement produced the highest ï¬lm thickness value at both the initial period and at 240s. Regarding viscosity, Superbond had the lowest initial value but the highest value at 240s. Variolink gave the highest initial value of viscosity, but the differences in the initial values among the other materials were small. During the whole period of testing, zinc phosphate cement gave the highest values of tan δ, and Panavia 21 showed no signiï¬cant change in any of the measured properties. The methods were able to distinguish the behaviour of different cement materials. Some resin cements produce larger than optimal values of ï¬lm thickness and in some cases this is related to a rapid increase in viscosity after mixing. It is expected that differences in the ability of cements to form thin ï¬lms will affect the seating of cemented restorations.
KEY WORDS: Rheological, luting cementations, crowns
- Article Price
- £15.00
- Institution Article Price
- £
- Page Start
- 23
- Page End
- 27
- Authors
- Saad A Osman, John F. McCabe
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- Title
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- Pg. End
- Effect of Five Staining Solutions on the Colour Stability of Two Acrylics and Three Composite Resins Based Provisional Restorations
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- Surface Microhardness of a Resin Composite: a Comparison of a Tungsten Halogen and a LED Light Curing Unit, in vitro
- 7
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- The effect of cooking method upon the titratable acidity of a popular vegetarian dish – Scope for reducing its erosive potential?
- 28
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