What is reverse curve in tooth preparation?
REVERSE CURVE When the direction of the mesiofacial wall is parallel to the direction of the enamel rods, thus creating a ‘s’ shaped curve in the proximal outline. It is created to: Provide butt joint in the preparation margin.
Which bur is used for Class 2 cavity preparation?
Most of the shaping of the cavity is done using Aerator and Diamond cutting burs such as Round bur, Inverted Cone bur, Straight fissure bur, Tapered Fissure Bur and Tungsten Carbide Burs.
How do you prepare a Class 2 cavity?
Continue to Class II Amalgam Restoration
- Obtain proper isolation of the tooth (e.g. rubber dam, isovac/isolite, etc.)
- Place the bur in the most mesial portion of the preparation outline, orient the bur 5º mesially, and brush upward to create occlusal divergence at the proximal wall of the dovetail.
What is recurrent caries?
Recurrent caries is a primary caries lesion next to a pre-existing filling. It usually forms cervically and interproximally due to plaque stagnation. 3. Recurrent caries is potentially serious as once dentine is reached it can spread rapidly.
What is axial wall depth?
6. The axial wall is 0.5-0.8 mm into dentin. 7. The reverse curve preserves the triangular ridge and facilitates the formation of a 90 degree angle between the proximal walls and the tangent of the proximal surface.
What is dovetail in cavity preparation?
dove·tail. (dŭv’tāl), A widened portion of a cavity preparation usually established to increase the retention and resistance form.
What is a bevel in dentistry?
Bevels are given at various angles depending on the type of material used for restoration and the purpose the material serves. Definition of Bevel: “Any abrupt incline between the 2 surfaces of a prepared tooth or between the cavity wall and the cavosurface margins in the prepared cavity”
What is line angle and point angle?
For purposes of description, the crowns and roots of teeth have been divided into thirds, and junctions of the crown surfaces are described as line angles and point angles. Line angle and point angle are used only as descriptive terms to indicate a location. …
Which amalgam is used in dental filling?
Approximately half of a dental amalgam filling is liquid mercury and the other half is a powdered alloy of silver, tin, and copper. Mercury is used to bind the alloy particles together into a strong, durable, and solid filling.
What is creep in dentistry?
Creep. Creep in dental amalgams refers to the gradual change in shape of the restoration from compression by the opposing dentition during chewing or by pressure from adjacent teeth. It was a phenomenon associated with the gamma-2 phase seen with low-copper alloys (about 6%) and resulted in deterioration of the margins …