The aim of restorative and esthetic dentistry is to restore the decayed or missing part of the teeth with a bio-compatible material that matches natural enamel in appearance and physical characteristics and maintain occlusal anatomy to promote proper oral function. Dental ceramic technology is one of the fastest growing areas of dental material research and development. The past decades have seen the development of several new groups of ceramics.

An emergency is an unforeseen circumstance calling for immediate action.Life threatening emergencies can and do occur in the practice of dentistry.They may happen to anyone, the dental patient, the doctor, members of the dental office staff, even a person who is simply waiting to accompany a patient home from the dental office. Although life threatening emergency situations does not occur frequently with in the typical dental practice, a number of factors may increase the rate at which these incidents arise.

In today's fast paced world, patients are requesting for treatment modalities requiring minimum time. This has created interest in clinicians to study the advisability & efficacy of root canal therapy in one visit. In general, attitudes and concepts concerning proven, time-tested treatment procedures are very slow and difficult to change in the health professions. We are often reluctant to abandon predictable treatment procedures because we fear a change to some new treatment modality may not result in the same outcome or rate of success we have come to expect.

The smear layer has become a force to be reckoned with during the last decade. Most dentists now know it exists but are often puzzled as to whether or not they should cope with it. Since the smear layer has been recognized, dentists have come to realize that they must renew their acquaintance with the science of dental materials so they can understand the relationships of the products they work with to the smear layer.

Bonding of restorative materials to hard dental tissues would be impossible without the use of acid solutions. It is the effect of these various acid solutions and pretreatments that results in the hard dental tissues being characterized by numerous microscopic porosities, which allows the resin to readily wet the surface and penetrate into these micro porosities. Once the resin penetrates into these micro porosities it can be polymerized to a form a mechanical bond to the hard dental tissues.

Die Verklebung von Restaurationsmaterialien auf Zahnhartsubstanz wäre ohne die Verwendung von Säurelösungen unmöglich. Die Wirkung dieser verschiedenen sauren Lösungen und Vorbehandlungen führt dazu, dass das Zahnhartgewebe durch zahlreiche mikroskopische Porositäten gekennzeichnet ist, die es dem Harz ermöglichen, die Oberfläche leicht zu benetzen und in diese Mikroporositäten einzudringen. Sobald der Kunststoff in diese Mikroporositäten eingedrungen ist, kann er polymerisiert werden, um eine mechanische Verbindung mit dem Zahnhartgewebe einzugehen.

Le collage des matériaux de restauration sur les tissus dentaires durs serait impossible sans l'utilisation de solutions acides. C'est l'effet de ces diverses solutions acides et de ces prétraitements qui fait que les tissus dentaires durs sont caractérisés par de nombreuses porosités microscopiques, ce qui permet à la résine de mouiller facilement la surface et de pénétrer dans ces microporosités. Une fois que la résine a pénétré dans ces microporosités, elle peut être polymérisée pour former une liaison mécanique avec les tissus dentaires durs.

The concept of minimum intervention dentistry has been well accepted and should be based on five generally accepted principles: scientifically orientated caries diagnosis of early lesions including adequate diagnostic devices; disease control by reduction of cariogenic bacteria/modification of the oral flora and patient education; remineralization of the earliest lesions; minimum surgical intervention of cavitated lesions; and repair in favor of replacement of defective restorations.