How do you prepare a Class 2 amalgam cavity?
Envision the cavity preparation outline and extent:
- Always keep the bur perpendicular to the long axis of the tooth.
- Follow the anatomical grooves of the tooth
- Leave a small “enamel shell” interproximally to protect the adjacent tooth from iatrogenic damage.
What is the ideal depth of the pulpal floor in the cavity preparation for amalgam?
A faciolingual width of no more than 1 to 1.5 mm and a depth of 1.5 to 2 mm are considered ideal, but this goal is subject to the extension of the caries. The pulpal floor, depending on the enamel thickness, is almost always in dentin (see Fig. 14-4, C).
What is the minimum cavity depth required for amalgam?
The minimum thickness for amalgam is 1.5mm, 1-2mm for cast metal and 2mm for porcelain.
How many point angles are there in a class II Mesio-occlusal cavity preparation?
For class II preparation (mesio-occlusal or disto-occlusal) 11 line angles and 6-point angles are as follows (Fig. 7.17). The following is the nomenclature for mesio-occlusal tooth preparation.
Why is Cavosurface angle 90 degrees?
Because enamel rods are perpendicular to the enamel surface ,the strongest enamel margin results in a cavosurface angle greater than 90 degrees.
What is a Class 2 dental restoration?
A Class II restoration has to recreate not only the natural contour of the tooth, but also the corresponding proximal contact. Many dentists consider this point, in particular, to be the most demanding part of the treatment.
How many line angles does a Class 2 cavity have?
For class II cavity preparation (mesioocclusal or disto-occlusal) 11 line angles and 6 point angles are as follows. The following is the nomenclature for mesio-occlusal cavity (Fig.
What is Cavosurface angle for amalgam?
Since long it has been thought that CSA for amalgam should be 90° to allow bulk of amalgam at the margin since it is brittle in nature, ; however, Elderton suggested that for wide cavities, cavosurface angle should be in the range of 105°to 115° permitting an amalgam margin angle (AMA) approaching 70°.
Which tooth would receive a Class 2 restoration?
Class II restorations in permanent molars and premolars; 4. Class V restorations in primary and permanent posterior teeth.
What should be the width of cavity preparation?
The dimensions of the cavity preparation: occlusal cavity depth: 1.5 mm, occlusal cavity floor mediodistal width: 2 mm; proximal box mediodistal width: 1 mm, axial wall height: 1 mm.
Why Vaseline is applied over GIC?
Similarly petroleum jelly also impedes the fluoride release, but to a very less extent. We suggest that in situations where the fluoride release property is more important than other properties it is better to coat the GIC with petroleum jelly or leave the restoration without any coating.
Why is Cavosurface margin 90 degrees for amalgam?
What is the ideal width of the isthmus?
The isthmus width is between 1/3 and ½ the labio-lingual intercuspal width of the tooth.
What is a Class II dental restoration?
Traditionally, Class II restorations were done with dental amalgam. Over the last 15 years, amalgam use has (obviously) sharply declined while composite use has risen higher and higher. Amalgam offered lots of advantages in Class II situations.
How many surfaces could a Class 2 restoration effect?
Potentially, a large Class II cavity may involve all five surfaces of molars. This occurs when there are carious lesions on both proximal surfaces and when the occlusal caries is extending buccally and lingually through the grooves.