Presentation on theme: "Several systems of tooth notation are available, but the systems commonly used in the UK are the FDI (Federation Dentaire International) and Palmer systems."— Presentation transcript:
Several systems of tooth notation are available, but the systems commonly used in the UK are the FDI (Federation Dentaire International) and Palmer systems. Tooth notation
The mouth is divided into four quadrants and each quadrant is given a number, starting with the upper right quadrant and working in a clockwise direction. For example, the upper left quadrant is 2. The teeth are then allocated a number starting from the midline, so all central incisors are 1 and all third molars are 8. Therefore the lower right second premolar is 45. Permanent teeth: Right 18 17 16 15 14 13 12 11 21 22 23 24 25 26 27 28 Upper Lower 48 47 46 45 44 43 42 41 31 32 33 34 35 36 37 38 Left
In this system, sometimes called the Tzigmondy–Palmer system, the dentition is divided into quadrants and the teeth in each quadrant are numbered 1 to 8 starting at the midline. Each quadrant is separated by a vertical line for right and left and by a horizontal line for upper and lower. Thus |6 is the upper left ﬁrst molar in the permanent dentition. Permanent teeth: Right 8 7 6 5 4 3 2 1 | 1 2 3 4 5 6 7 8 Upper Lower 8 7 6 5 4 3 2 1 | 1 2 3 4 5 6 7 8 Left This system works well for hand-written notes but is more difﬁcult for computerised notes and printed letters and therefore the lines are sometimes replaced by two letters describing the quadrant, for example UR8 is the upper right third molar tooth.
Conventionally, cavities are prepared using a combination of hand instruments and rotary instruments. Hand instruments: (a) straight probe; (b) Briault probe; (c) excavator; (d) ball-ended plastic; (e) ﬂat plastic; (f) 1/2 Hollenbach; (g) amalgam plugger; (h) gingival Margin trimmer; (i) hatchet; (j) Teﬂon-coated composite instrument; (k) Teﬂon-coated composite instrument; (l) Amalgam carrier.
The slow-speed handpiece is driven either by com- pressed air or directly by an electric motor. The speed of the handpiece ranges from 0 to 40 000 rpm. The most efﬁcient cutting is achieved with a straight handpiece, but this is difﬁcult to use in the mouth and is therefore restricted to extraoral use, such as adjusting temporary crowns and dentures. The contra-angle handpiece is used for the removal of caries, polishing and ﬁnishing.
Straight handpiece Electric motor Contra-angled slow speed handpiece
The high-speed handpiece is driven by compressed air and is sometimes referred to as an air-turbine. It is used for cutting through enamel and dentine and removing previous restorations. It has a speed of 250 000–500 000 rpm and, to keep it cool, a water spray is directed at the cutting part of the bur which is held in the head of the handpiece by friction. A ﬁbreoptic light in the head of the handpiece aids visibility.
Most often called burs, but also available are wheels, discs, rubber points, rubber cups and stones Each has a particular function (cutting, polishing, ﬁnishing or caries removal) Are made from various materials (tungsten carbide, diamond and steel) Can have ﬂutes (the cutting edges) The end of the shank determines which handpiece the attachment will ﬁt into: Long straight shank – straight handpiece Latch grip – conventional type/slow speed handpiece Friction grip shank – air turbine handpiece/high speed handpiece Most often called burs, but also available are wheels, discs, rubber points, rubber cups and stones Each has a particular function (cutting, polishing, ﬁnishing or caries removal) Are made from various materials (tungsten carbide, diamond and steel) Can have ﬂutes (the cutting edges) The end of the shank determines which handpiece the attachment will ﬁt into: Long straight shank – straight handpiece Latch grip – conventional type/slow speed handpiece Friction grip shank – air turbine handpiece/high speed handpiece
Functions and precautions An amalgam capsule contains amalgam material (contents will vary depending on the manufacturer) Care must be taken when handling amalgam to prevent inhalation of vapours, skin absorption and inhalation of air-borne particles Amalgamator is used to titrate amalgam prior to use Amalgamators must have a plastic covering over the area where the amalgam is titrated for safety in case of displacement
When the pulp suffers irreversible pulpitis, the only way to retain the natural tooth is by complete removal of the pulp.
Functions and precautions Finger instruments Disposed of in the sharps’ container Used to remove the intact pulp ‘Barbs’ on the broach snag the pulp to facilitate removal They need to be used cautiously as they can bind and break in the canal Varieties Available in different sizes and widths
Function, features and precaution Finger instrument Colour coded by size. The 6 colours used most often are: size 15 (white); 20 (yellow);25 (red); 30 (blue); 35 (green); 40 (black). Also available in size 6 (pink), 8 (grey) and 10 (purple) Operator gradually increases the size of the ﬁle to smooth, shape and enlarge canal The larger the number of the ﬁle, the larger the diameter of the working end Disposed of in the sharps’ container Varieties Different lengths: 21mm, 25mm and 30mm Hedstrцm ﬁles, Flexoﬁles
Lentulo spiral ﬁller/rotary paste ﬁller Function and features Small ﬂexible instrument used to place materials into the canal Fits into the conventional handpiece Use with caution as it can be easily broken Different sizes available
Black’s classiﬁcation is as follows: ■ Class I: caries affecting pits and ﬁssures; commonly used to refer to caries affecting the occlusal surfaces of premolars and molars. ■ Class II: caries affecting the proximal(contact) surfaces of posterior teeth(molars and premolars). ■ Class III: caries affecting the proximal surfaces of anterior teeth(incisors, canines). ■ Class IV: caries affecting the proximal surfaces of anterior teeth and also including the incisal angle(cutting edge). ■ Class V: caries affecting the cervical surfaces. In some American issues we can find the additional VI class.Class VI – caries-resistant zones of teeth- cusps and equator of the tooth.