Tooth dental drill

The glass polyalkenoate cement uniquely combines translucency with the ability to bond to untreated tooth material and bone. Indeed, the only other cement to possess translucency is the dental silicate cement, while the zinc polycarboxylate cement is the only other adhesive cement. It is also an agent for the sustained release of fluoride. For these reasons the glass polyalkenoate cement has many applications in dentistry as well as being a candidate bone cement. Its translucency makes it a favoured material both for the restoration of front teeth and to cement translucent porcelain teeth and veneers. Its adhesive quality reduces and sometimes eliminates the need for the use of the dental drill. The release of fluoride from this cement protects neighbouring tooth material from the ravages of dental decay. New clinical techniques have been devised to exploit the unique characteristics of the material (McLean Wilson, 1977a,b,c Wilson McLean, 1988 Mount, 1990). 

Archaeological teeth samples were mechanically cleaned by abrasion with a Patterson NC-350 dental drill equipped with an inverted-cone caibide burr (White burrs HP-59 type 2 class 2). This removed any adhering otganic matter or contaminants as well as the outermost layers of tooth enamel, which are most susceptible to diagenetic contamination (44, 48). Approximately 5-10 mg of tooth enamel were then removed with a Patterson NC-350 dental drill equipped with a carbide burr. 

In order to carry out the various processes involved in dental repair, the tooth generally has to be cut with some sort of instrument. This is usually a rotary bur of the so-called dental drill. The cutting process results in the formation of a layer known as the smear layer on the surface of the tooth (O Fig. 56.1). The smear layer is thin, typically 1-2 pm deep, and is very tenacious. It consists of mineral phase embedded in denatured collagen, and is essentially material with a less ordered structure than uncut enamel or dentin. 

The clinical technique known as Atraumatic Restorative Treatment (ART) has been developed since the mid-1980s in response to dental clinical needs in Third World countries. It is an important application of adhesive dental materials, specifically conventional glass-ionomer cements, and would not be possible without this type of adhesive material (Frencken et al. 2004). ART involves the removal of carious tooth tissue with hand instruments rather than conventional dental drills. These hand-held instruments are formed as spoon-shaped excavators, and come in graded sizes. 

In addition to these features of lack of caries management and a ruthless policy of tooth extraction, low- and middle-income countries typically have unreliable or non-existent electrical power supplies. This means that electrically driven drills and burs cannot be used in routine clinical dentistry. The high price of such dental units is a further problem in low- and middle-income countries and contributes to their relative scarcity. 

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