Orthodontics II Laboratory/Midterm PDF

ORTHODONTICS II LABORATORY / MIDTERM AND FINALS – FIRST TERM 4TH YEAR LESSON 1: ORTHODONTIC MATERIALS Instruments & Pliers BAND CUTTING SCISSORS Brackets...

ORTHODONTICS II LABORATORY / MIDTERM AND FINALS – FIRST TERM 4TH YEAR LESSON 1: ORTHODONTIC MATERIALS Instruments & Pliers BAND CUTTING SCISSORS Brackets Available in either straight or curved pattern, and Wires long and short cutting edge pattern It is made from especially hardened stainless ORTHODONTIC INSTRUMENTS & PLIERS steel with tungsten carbide inert cutting tip FEATURES OF ORTHODONTIC INSTRUMENTS Purpose: for cutting thin metal bands or band material FEATURE & RATIONALE Stainless steel extremely corrosion material resistant Tungsten carbide stiffer and denser tips steel Gold brazing for longer instrument life Serration on for grip MERSHON BAND PUSHER working ends improvement Handle is cylindrical and working end is serrated Bow out handles comfortable A hollow anatomically formed grip handle handling makes the band pusher light Rounded tips for patient comfort The serrated rectangular tip provides a good and safety transfer of force when positioning bands Purpose: used to push bands so as to seat them and/or adapt them to the exact contour of the CLASSIFICATION OF ORTHODONTIC PLIERS / teeth INSTRUMENTS INSTRUMENTS USED FOR PLACEMENT OF SEPARATORS o Separator Placement Plier BAND PREPARATION INSTRUMENTS o Band Cutting Scissors o Mershon Band Pusher o Nylon Band Seater o Band Crimping Plier BAND REMOVING PLIER NYLON BAND SEATER o Posterior Band Removing Plier Generally made of high impact plastics or wood The biting surface is a tin inlay. Its shape may be SEPARATOR PLACEMENT PLIER round, square, or triangular (allows easy access Made of stainless steel with sprint back action to interproximal area) with a serrated surface Barrel-shaped tip prevents slippage of the finish module, reduces the risk of tissue damage Purpose: for patient to bite on the surface with Angled beaks facilitate easier placement of the tin inlay tip resting on the lug or the band elastic separators in posterior areas edge Purpose: for expanding elastic separators or separating rings before positioning them interdentally DE LUNA, FIONA YSABELLA Z. | 1  BAND CRIMPING PLIER Purpose: to contour the gingival surface of preformed bands to provide better tooth anatomy DIRECT BONDING BRACKET HOLDER With reverse action type handle wherein the beak opens up upon pressing the handle Beaks are diamond shaped with serrations to grip the bracket POSTERIOR BAND REMOVING PLIER Flat end of the handle used to press the bracket Purpose: to remove posterior metal bands with into position for bonding maximum patient comfort Purpose: holds any type of bracket CLASSIFICATION OF ORTHODONTIC PLIERS / INSTRUMENTS BRACKET POSITIONING INSTRUMENTS BRACKET REMOVING PLIER o Boone gauge the wide tip wedge between both the edges of o Bracket positioning height gauge the base of the bracket and the tooth surface, o Direct bonding bracket holder easily lifting off the bracket BRACKET REMOVING PLIER Available in two forms: o Anterior Bracket Removing Plier o Straight: for anterior debonding o Posterior Bracket Removing Plier o 60 degrees angled tip: for posterior Purpose: for removing bonded brackets BOONE GAUGE most frequently used bracket positioning aid Accurately measures height of bracket placement from the incisal edge Purpose: simplifies seating the bracket on the teeth with exactly the right distance between bracket slot and incisal edge with pencil lid or metal tips CLASSIFICATION OF ORTHODONTIC PLIERS / INSTRUMENTS WIRE CUTTING INSTRUMENTS o Pin & Ligature Wire Cutter o Distal end wire cutter o Heavy wire cutter PIN & LIGATURE WIRE CUTTER designed for accuracy right to the tip, for smooth BRACKET POSITIONING HEIGHT GAUGE cutting of soft ligature wires and lock pins and accurately measures height of bracket elastomerics placement from the incisal edge Purpose: used on ligatures or wires not more than Purpose: simplifies seating the bracket on the 0.015mm in diameter teeth with exactly the right distance between bracket slot and incisal edge DE LUNA, FIONA YSABELLA Z. | 2  DELA ROSA ARCH CONTOURING PLIER has guiding grooves for forming round and square arches 0.016” to 0.022” Purpose: used to accentuate the curvature in the arch wire DISTAL END WIRE CUTTER Is capable of cutting archwires up to 0.022 x 0.028” both intraoral and extraoral method Has a “safety” mechanism to hold the cut archwire so it does not fall intro the patient’s BIRD BEAK PLIER mouth an extremely versatile utility plier designed for Purpose: used exclusively to cut the distal end of working round wire up to 0.030” in diameter the wire protruding out of the molar tubes Purpose: used to bend appliance and orthodontic wires HEAVY WIRE CUTTER Heavier and larger than the pin & ligature wire JARABAK LIGHT WIRE PLIER cutter longer and more gradually tapered beaks than Purpose: used to cut all wires up to 0.020 round the bird beak pliers It comes with or without serrations on its flat beak Purpose: used for arch form and spring preparations; may be used for hard wires up to 0.020” diameter CLASSIFICATION OF ORTHODONTIC PLIERS / INSTRUMENTS ARCH FORMING INSTRUMENTS o Turret o Dela Rosa Arch Contouring Plier o Bird Beak Plier o Jaraback light wire plier CLASSIFICATION OF ORTHODONTIC PLIERS / INSTRUMENTS TURRET UTILITY PLIER the wire slotter body is made of stainless steel o Howe plier Available in different versions and colors - blue, o Weingart Universal black, gold, purple, green depending on torque o Three-prong plier adjustments and wire size OTHERS Purpose: used for preparation of archwires with o Mathieu Needle Holder or without torque adjustment HOWE PLIER Purpose: used to hold arch wires and to seat individual anterior bands in place DE LUNA, FIONA YSABELLA Z. | 3  IDENTIFICATION SYSTEM WEINGART UNIVERSAL PLIER color code quadrant where you will place the the bend in the beak facilitates easy grasping of quadrant the archwire and guiding into buccal tubes By quadrant with a removable colour coded dot Capable of bending wires up to 0.020” diameter for easy selection Purpose: used to guide and move the archwire Yellow = 1st Quadrant in and out of placement and used to bend the Yellow part / colored part dapat nasa distal part end of archwires ng ngipin VERTICAL SCRIBE LINE for easy and accurate placement on the long axis GENEROUS UNDER TIE-WING AREA for easy ligation THREE-PRONG PLIER SMOOTH FACIAL CONTOURS Has three precision aligned tips, which ensures for maximum patient comfort consistent bends in lingual bars and wires Allows a V-shaped bending curve 80 GAUGE FOUL MESH BASE Purpose: used for the activation or adjustment of for increased bond strength appliances like quadhelix appliance At the back of bracket Where we put the cement TORQUE IN BASE for precise level slot lineup during the finishing phase METAL INJECTION MOULDING (MIM) MATHIEU NEEDLE HOLDER Technique for accurate bracket structure has a convenient and practical design that is ideal for ligation INTEGRATED BALL HOOK Its serrated tips allow better gripping of the thin for easy engagement of elastics ligatures and elastomeric modules Purpose: used for the placement of ligatures and THE BRACKET MATERIAL MUST BE: elastomeric modules Hygienic, nontoxic Resistant to corrosion Must resist forces applied to it by the wire Esthetic Not absorb water Not be discolored by oral liquids Have minimal bracket-wire friction ORTHODONTIC BRACKETS BASED ON MATERIAL, BRACKET CAN BE BROADLY GROUPED AS: A. Metal bracket o Stainless steel 316 and 318 type o Low nickel SS (stainless steel) 2205 o Nickel free pure titanium/titanium alloy (Ti-6A1- 4V) o Cobalt-chromium o Gold-brackets B. Non-metal brackets o Plastic brackets o Porcelain brackets o Polycarbonate brackets o Polycarbonate brackets with metal slots DE LUNA, FIONA YSABELLA Z. | 4  MANUFACTURING METHODS OF METAL BRACKETS METAL BRACKETS Most of the conventional metal brackets are STAMPED BRACKETS made up of stainless steel o this process feeds sheet metal into a press Low cost where a tool and die form it into a metal part Sufficient strength to withstand forces of o Almost routinely used until the prescription deformations straight wire appliances were introduced Resistance to corrosion due to chromium Excellent formability and good mechanical CAST BRACKETS properties o molten metal is poured into a pre-made mold The stainless steel of 316 and 318- type steel is o More accurate and durable used for manufacturing orthodontic brackets o Clearly are superior so most the brackets and with 18-8 SS formulation (18% chromium and 8% tubes for contemporary appliances now are nickel) castings Stainless steel brackets have been in extensive use and have shown reasonable strength, bio- NON METALLIC BRACKETS acceptability and proven track record of clinical tooth colored or clear brackets acceptability However, it has 2 disadvantages: PLASTIC BRACKETS o Not aesthetic initially made of polycarbonate and plastic o May release nickel and chrome into the oral molding powder (Plexiglas) environment It is useful only when complex tooth movements ▪ If nickel is leached from orthodontic are not required appliances, Type IV hypersensitivity reaction Disadvantages OF NON-METALLIC BRACKETS: can occur. (Type IV hypersensitivity is like 1. Staining and Discoloration contact dermatitis) 2. Fragile (breaks under stress) 3. Poor dimensional stability (arch wire slot) NICKEL 4. Friction between plastic bracket and metal most brackets currently used are made of archwire austenitic (more anti corrosion) stainless steel containing 18% chrome and 8% nickel The significant nickel content of stainless steel can induce mucosal allergic reactions About 10% of the population have some degree of nickel sensitivity GOLD CERAMIC BRACKETS was abandoned as a metal alternative because made of monocrystalline and polycrystalline of its performance and cost ceramic material Durable & stain-resistant TITANIUM Can be custom-molded for individual teeth AS AN ALTERNATIVE TO STAINLESS STEEL Dimensionally stable high success rate in bonding DISADVANTAGES: Resilient than steel and absorbs impact better 1. Fracture tendencies Nickel-free content 2. Friction with bracket slots Hypoallergenic properties 3. Wear on teeth contacting a bracket Biocompatible 4. Enamel damage during debonding FRACTURES OCCUR IN TWO WAYS: Modern edgewise appliances uses brackets or 1. Loss of part of the brackets during archwire tubes that are custom-made for each tooth, with changes or eating the goal of minimizing the number of bends in 2. Cracking of the bracket when torque forces are archwires need to produce an ideal applied arrangement of the teeth, hence, the “straight wire” name. DE LUNA, FIONA YSABELLA Z. | 5  A new design of the ceramic bracket is ORTHODONTIC WIRES borrowed from the design of the metal Archwires are the base wires, which are reinforced plastic brackets in which a metal slot engaged in brackets of the various appliance is incorporated in ceramic bracket. This is to systems reduce friction between bracket and wire Used to provide a proper arch form and/or Another feature of this appliance is the ease of provide a stable base to which the auxiliaries debonding (bracket removal) via a vertical can be attached to generate the tooth moving scribe line placed in the base of the bracket forces SELF - LIGATING BRACKETS MANUFACTURING OF ORTHODONTIC WIRES They have a built-in metal face, which can be The starting point: casting of an ingot having the opened and closed appropriate alloy composition. ACTIVE - have a sliding sprint clip, which This ingot is then subjected to a series of encroaches on the slot from the labial aspect, mechanical reduction operations until the cross potentially placing an active force on the section is sufficiently small for wire drawing archwire. Slot Depth between 0.0175” - 0.020” PASSIVE - have a slide that opens and closes The elastic behavior of ang material is defined in vertically and creates a passive labial surface to terms of its stress - strain response to an external the slot with no intention to invade the slot. Slot load Depth approx. 0.028” STRESS o Internal distribution of the load, defined as force per unit area STRAIN o Internal distortion produced by the load, defined as deflection per unit length DIRECTIONS OF FORCES RELATED TO STRESS AND STRAIN If there is an increase in the length of a piece of TYPES: metal due to stress, this is referred to as Tensile 1. Spring Clip Strain. Tension 2. Retaining Clip 3. Rigid Clip If there is a reduction in length, this is referred to The principal advantage of a rigid clip is the as Compressive Strain. Compression reduction of friction between the wire and Shear Strain is the bending or twisting of wires. bracket - Shear (arrows magkapatong) o Speed Bracket Spring Clip – Active For orthodontic purposes, three major properties of beam materials are critical in defining their clinical usefulness: 1. Strength - a force value, that is a measure of the maximum possible load. Greatest force a wire o SmartClip Bracket Retaining Spring – Passive can sustain or deliver. 2. Stiffness (or its inverse springiness) - the rate of force delivery require for a unit activation. Proportional to the modulus of elasticity and o Damon Bracket Rigid Clip – Passive cross section of a given wire. The measurement of force required to deform the material. 3. Range - maximum amount of elastic activation before the onset of a permanent or plastic deformation. Determined from the 0.1% offset point on the force-deflection diagram. Kung hanggang san kaya ng wire na di siya permanently madadamage. CHARACTERISTICS OF ORTHODONTIC WIRES Large Springback Low stiffness DE LUNA, FIONA YSABELLA Z. | 6  High formability YIELD STRENGTH High stored energy The stress at which a material exhibits a specified Low surface friction limiting deviation from proportionality of stress to Biocompatibility and environmental stability strain Capability to be welded or soldered to auxiliaries The property that represent the stress value at or attachments which a small amount of plastic deformation occurred SPRINGBACK The wire will not return to the original state after maximum elastic deflection or working range the deformation It is also a measure of how far a wire can be deflected without causing permanent TENSILE STRENGTH deformation The maximum stress that a material can Related to the ratio of yield strength (YA) to the withstand before failure in tension modulus of elasticity (E) of the material (YS/E). The wire will not return to its original shape, but clinically useful springback will occur unless the STIFFNESS OR LOAD DEFLECTION RATE failure point is reached. This is the force magnitude delivered by an appliance and is proportional to the modulus of PROPORTIONAL LIMIT elasticity (E). the highest stress at which stress is directly Measurement of material’s elasticity and its proportional to strain resistance to deformation. FORMABILITY high formability provides the ability to bend a wire into desired configurations such as loops, coils, etc. without fracturing the wire. MODULUS OF RESILIENCE this property signifies the energy storing capacity of the wire It is represented by the area under the line describing elastic deformation of the wire. How well the wire can handle the force without deformation. FRICTION The preferred wire material for moving teeth relative to the wire should produce the least amount of friction at the bracket/wire interface. Excessive friction can result in loss of anchorage or binding accompanied by little or no tooth movement. BIOCOMPABILITY AND ENVIRONMENTAL STABILITY Biocompatibility includes resistance to corrosion and tissue tolerant to elements of the wire. WELDABILITY / JOINABILITY the ability to attach auxiliaries to wires by soldering or welding A filler metal may or may not be used to join the work pieces DE LUNA, FIONA YSABELLA Z. | 7