Operative dentistry is the art and science- Lect. 1

Operative dentistry is the art and science of the diagnosis, treatment, and prognosis of defects of teeth that do not require full coverage restorations for correction. Such treatment should result in the restoration of proper tooth form, function, and esthetics while maintaining the physiologic integrity of the teeth in harmonious relationship with the adjacent hard and soft tissues, all of which should enhance the general health and welfare of the patient (The art and science of operative dentistry / senior editor, Clifford M. Sturdevant; co-editors, Theodore M. Roberson, Harald O. Heymann, John R. Sturdevant. 3rd ed. c1995).Operative dentistry is the art and science of the diagnosis, treatment, and prognosis of defects of teeth that do not require full coverage restorations for correction. Such treatment should result in the restoration of proper tooth form, function, and esthetics while maintaining the physiologic integrity of the teeth in harmonious relationship with the adjacent hard and soft tissues, all of which should enhance the general health and welfare of the patient (The art and science of operative dentistry / senior editor, Clifford M. Sturdevant; co-editors, Theodore M. Roberson, Harald O. Heymann, John R. Sturdevant. 3rd ed. c1995).
G. V. Black: (Chicago, Illinois 1836-1915)
In the first decade of the twentieth century an American dentist and teacher, G. V. Black, established principles governing the design of cavities and suggested steps in their preparation. He based these principles on what was known at the time about the natural history of caries and the restorative materials available. Since his principles have now been so extensively modified, and since many conditions in addition to caries are treated operatively, no further reference will be made to Black’s principles. Black also described a classification of carious lesions which is still widely used in dental schools. However, this classification is now regarded as incomplete in that it does not include root caries and secondary caries. Also, it does not include non-carious lesions, which are treated in the same way as carious lesions.
Cavity preparation: The mechanical alteration of a defective, injured, or diseased tooth in order to best receive a restorative material which will re-establish a healthy state for the tooth including esthetic corrections where indicated, along with normal form and function. Axial wall an axial wall is an internal wall parallel with the long axis of the tooth. Pulpal wall a pulpal wall is an internal wall that is perpendicular to the long axis tooth and occlusal of pulp.
When is a restoration needed?
One of the most important reasons for placing a restoration is to aid plaque control. Other reasons where a restoration may be needed include:
• the tooth is sensitive to hot, cold, and sweet.
• the pulp is endangered.
• previous attempts to arrest the lesion have failed and there is evidence that the lesion is progressing.
• function is impaired.
• drifting is likely through loss of contact point.
• the carious lesion is unsightly.
Dental amalgam:
Amalgam is an alloy of mercury with silver and other metals such as tin and copper to give a set material which does not adhere to tooth structure and therefore needs to be retained within the cavity by mechanical means. Although amalgam does not adhere to the tooth surface, it has been shown that there is a reduction in micro-leakage around amalgam restorations over a period of time, and this is attributed to corrosion products forming at the tooth– amalgam interface. Amalgam is condensed into a cavity with more force than other materials and this must be resisted by the design of the cavity preparation. Until now the concept has been to remove diseased hard tissue and replace it with little more than a plug in a hole. Plastic restorations are used intracoronally. Materials include amalgam, resin composite, glass ionomer less commonly resin modified glass ionomers and cermets, although their frequency of use is increasing. Placement of a satisfactory restoration requires sound cavity preparation. These materials require considerably less amount of tooth preparation. But their success is limited due