Instruments and techniques 4/26/2017 Dr. Mumena

4/26/2017

Tooth extraction instruments Two types of instruments for simple extraction of permanent teeth and extraction of all primary teeth, these are: Dental forceps Dental elevators They are all made to conform to ISO (International organization of Standards). 4/26/2017

Dental forceps Extraction instruments consisting of two blades with a joint to connect to the handle. Many designs available Designs fall into two groups: Forceps for the Maxillary teeth: Handle and beak of the forceps form more or less a straight line Forceps for the mandibular teeth: Handle form more or less a right angle with the beaks of the forceps 4/26/2017

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Dental forceps cont…. Choice of forceps depends on Morphology of the tooth Root anatomy Number of roots Extraction is a surgical approach care must be taken when extracting tooth (Aseptic technique) Instruments must be sterile before extraction 4/26/2017

Maxillary forceps Forceps for upper teeth have: Handles in the same long axis as the blades except for upper molars which is slightly sigmoid (Reason is to allow the beaks to align with long axis of the teeth) Anterior teeth (Incisors & Canines) and retained roots forceps have rounded tips Shorter blade forceps can be used for canines because of their bulkier roots than anteriors 4/26/2017

Maxillary forceps cont… Molar forceps have two broader blades One is pointed or beaked Recall morphology of maxillary molars (3 roots: 2 buccal roots, one palatal) Forceps are designed one for left side, another for right side) Forceps has beaked and smooth blades 4/26/2017

Maxillary molars cont… Beaked blade designed to fit into the trifurcation between mesiobuccal and distobuccal root (beak to cuccal Smooth blade designed to approximate closely to the palatal root 4/26/2017

Maxillary premolar forceps; Blades and handle not in a perfectly straight line Palatal and buccal lips of the blades consist of single curves that conform to the curvature of the root of the tooth. 4/26/2017

Maxillary anterior teeth: Blades and handle in pretty straight line. Inside of blades differ in that the palatal beak is slightly smaller and the area is also slightly smaller. 4/26/2017

Maxillary root forceps: Blade is thinner (securing small root fragment). Angle between blade and handle differ slightly depending on the specific design. 4/26/2017

Lower teeth forceps All the forceps have a straight handle at right angle to the blades The blade pattern for anterior teeth (Incisors & canines) is the same for the upper teeth They have rounded tips Forceps for molars recall anatomy (Two roots) Forceps have two beaked blades to fit between buccal and lingual root birfurcation (Mesial and Distal roots) 4/26/2017

Lower anterior forceps applied to one root of lower molars 4/26/2017

Mandibular forceps: Mandibular molar forceps: Both blades has protrusion/beaks to fit in between the two roots of molars. Variation in wisdom teeth: One for left 8 and one for right 8. Another design is cowhorn; beak has two conically bent parts that during extraction wedge in between the mesial and buccal roots (It is like the cow’s horn) 4/26/2017

Position of lower molar forceps beaks at the neck of tooth 4/26/2017

Use of forceps for extraction (Technique) Successful extraction technique depends on: Careful use of controlled force Obtaining adequate access to the tooth Creating unimpeded path of removal Degree of force is greater for molars than for the anterior teeth, care taken ensure that forceps blade shave close contact with root surface 4/26/2017

Use of forceps for extraction (Technique) Care taken: Intimate contact of the whole inner edge of the beak to the crown of the tooth is ideal (Correspond to the force applied). Cross sectional shape of the root governs the movement the operator has to make to achieve extraction with forceps in close contact 4/26/2017

Use of forceps for extraction (Technique) E.g. incisors are thinner mesiodistally then buccolingual (movement Movement should be in the plane the tooth is the strongest (labiolingually) 4/26/2017

Elevators Elevators are single bladed instrument used to aid extraction or complete extraction of tooth Uses: Luxation of tooth: widening periodontal ligament making tooth mobile Complete extraction of tooth or root: Elevate tooth out of socket using bone as fulcrum (Not tooth) There are many different types of elavators 4/26/2017

Elevators Two common example of elevator are Warwick james Coupland 4/26/2017

Warwick James elevators Have small operating hands Available as left, right & straight Tip inserted between the tooth root and the socket wall, Rotational movement applied 4/26/2017

Warwick James elevators 4/26/2017

Warwick James elevating retained primary roots 4/26/2017

Couplands Are available in straight pattern only Three sizes only available (1, 2 & 3) Can be used as bone chisels or to release periodontal membrane As chisel used to press gentle under the gingival margin of the tooth to be extracted Used in rotational manner 4/26/2017

Couplands 4/26/2017

Use of elevators Mechanical principles of elavator application are: Lever Wedge Wheel and axle 4/26/2017

Elevators as lever Elevator are used primarily as a lever A dental lever is a dental mechanism for transmitting a modest force, with the mechanical advantages of a long lever arm and a short effectors arm, into a small movement against great resistance. 4/26/2017

Elevators as lever When a dental elevator is used for tooth extraction, a purchase point and a dental crane pick can be used to elevate the tooth or a tooth root from the socket. The small, straight dental elevator is frequently used to help mobilize teeth in a similar fashion without the preparation of a purchase point. 4/26/2017

Elevators as a wedge Used as a wedge Dental forceps is useful for the extraction of teeth in several different ways. First, the beaks of the dental extraction forceps are usually narrow at their tips; they broaden as they go superiorly. There should be a conscious effort made to force the tips of the dental forceps into the periodontal ligament space to expand the bone and force the tooth out of the dental socket 4/26/2017

Elevators as a wedge The wedge principle is useful when a straight dental elevator is used to luxate a tooth from its socket. A small dental elevator is forced into the periodontal ligament space, which displaces the root toward the occlusion and therefore out of the socket 4/26/2017

Elevators used as a wheel and axle This is most closely identified with the triangular, or pennant- shaped dental elevator. When one root of a multiple-rooted tooth is left in the alveolar process, the pennant-shaped dental elevator is positioned into the socket and turned. The dental handle then serves as the axle and the tip of the triangular elevator acts as wheel and engages and elevates the tooth root from the socket. 4/26/2017

Dental forceps Principles of dental forceps use The primary dental instrument used to remove a tooth from the alveolar process is the extraction dental forceps. Dental elevators may help in the luxation of a tooth, But the instrument that does most of the work are the dental forceps. 4/26/2017

Principles of dental forceps use The goals of dental forceps use are two-folds: expansion of the bony socket by use of the wedge- shaped beaks of the forceps and the movements of the tooth itself with the forceps, and removal of the tooth from the socket, sometimes with the use of dental microscopes. 4/26/2017

Tooth extraction: The removal of teeth from the alveolar process employs the use of several mechanical principles and simple machines: the lever, wedges, and the wheel and axle Instruments for removing the tooth from the alveolar process (socket): Dental extraction forceps (different types) Dental elevators (different types) 4/26/2017

Principles of dental forceps use There are five major motions that the forceps can apply to luxate the teeth and expand the bony socket: Apical pressure. Buccal pressure. Lingual pressure. Rotational pressure. Tractional forces. 4/26/2017

Apical pressure. Results in minimal movement of the tooth in an apical direction and expansion of the tooth socket by the insertion of the beaks down into the periodontal ligament space. Thus apical pressure of the forceps on the tooth causes bony expansion. A second major accomplishment of apical pressure with the extraction forceps is that the fulcrum, the center of the tooth’s rotation, is places more apically. 4/26/2017

Apical pressure Since the tooth is moving in response to the force placed on it by the forceps, the forceps becomes the instrument of expansion. If the fulcrum is high, their is a larger amount of force on the apical region of the tooth, which increases the chance of fracturing the root. If the beaks of the forceps are forced a bit into the periodontal ligament space, the center of rotation is moved apical, which results in greater movement of the expansion forces at the crest of the ridge and less force moving the apex of the tooth lingually. This process decreases the chance for apical root fracture. 4/26/2017

Buccal pressure. Buccal pressure results in expansion of the buccal plate, particularly at the crest of the ridge. It is important to remember that although buccal pressure causes expansion forces at the crest of the ridge, It also cause lingual apical pressure. 4/26/2017

Lingual pressure. Lingual pressure is similar to the concept of buccal pressure but is aimed at expanding the lingual crestal born, at the same time, avoiding excessive pressure on the buccal apical bone. 4/26/2017

Rotational pressure. Rotational pressure, as the name implies, rotates the tooth, which cause some internal expansion of the tooth, which causes some internal expansion of the tooth socket. The teeth with single conical roots, such as the maxillary incisors and mandibular premolars whose roots are not curved, are most amenable to luxation and bony expansion by this technique. Teeth that have other than conical roots or that have multiple roots-especially if those roots are curved- are more likely to fracture when using this type of pressure. 4/26/2017

Tractional forces. Tractional forces are useful for delivering the tooth from the socket once adequate bony expansion is achieved. Tractional forces should be limited to the final portion of the extraction process and should be gentle. 4/26/2017

Conclusion: there are a variety of forces that can be used to remove teeth. A strong apical force is always useful and should be applied whenever forceps are adapted to the tooth. Most teeth are removed by a combination of buccal and lingual forces. 4/26/2017

Conclusion Since maxillary buccal bone is usually thinner and the palatal bone is a thicker cortical bone, maxillary teeth are usually removed by strong; buccal forces and less vigorous palatal forces. 4/26/2017

Conclusion In the mandible the buccal bone is thinner from the midline posterior to the area of the molars. The incisors, canines and premolars are removed primarily as a result of strong buccal force and less vigorous lingual pressure. The mandibular molar teeth has stronger buccal bone and usually require stronger lingual pressure that the other teeth in the mouth. 4/26/2017

Conclusion Rotational forces are useful for single rooted teeth that have conical roots and no severe curvatures at the root end. The maxillary incisors, particularly the central incisors and the mandibular premolars especially the second premolars, are most amenable to rotational forces 4/26/2017