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89 Cards in this Set
- Front
- Back
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Association between bacterial and apical periodontitis
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Willoughby Dayton Miller
- Found bacteria in three basic morphologies |
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Routes of Root canal infection
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- Caries
- Restorative procedures - Trauma induced fractures - Scaling and root planing |
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Three basic reactions to protect pulp
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- Decrease in dentin permeability
- Tertiary dentin formation - Inflammatory and immune reactions |
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Dentinal tubule diameter
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Largest near pulp and smallest in periphery near enamel or dentin
0.9-2.5 nanometer - Entirely compatible with cell diameter of most oral bacterial species. 0.2 - 0.7 nano-meter |
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Delay of bacterial invasion
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- Outward movement of dentinal fluid and tubular contents in vital teeth
- Dentinal sclerosis beneath a carious lesion - Tertiary dentin - Smear layer - Intratubular deposition of fibrinogen |
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Odontoblast movement
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Dehydration, cold, and osmosis moves process outward
- Only heat moves process inward |
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Problems in pulpal ability to respond to external irritants
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- Enclosed in noncompliant environment
- Lacks sufficient collateral circulation |
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Degree of physical irritation caused by procedure
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Heat - 10deg caused 15% irreversible pulpitis. 20deg rise caused 60% irreversible pulpitis
Dessication - During cavity and crown prep, odontoblastic nuclei are aspirated into dentinal tubules and cause pulpal inflammation Vibration |
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Types of Endodontic infections
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Intraradicular infection
- Caused by microorganisms colonizing the root canal system and can be subdivided into three categories - Primary infection - Secondary: 2ndary to intervention - Persistent: Caused by microbes that were members of a primary or secondary infection and has resisted intracanal antimicrobial procedures |
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Most common bacteria found in failed root canals
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Enterococcus Faecalis
Others: F. Nucleatum Prevotella species |
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Sources of nutrients for bacteria
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- Necrotic pulp tissue
- Proteins and glycoproteins from tissue fluids and exudate that seep into root canal system via apical and lateral foramens - Saliva that coronally penetrate into root canal - Products of bacterial metabolism |
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The big three
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Kakehashi - Germ free rat studies
Moller - Same as Kakehashi but on monkies Sundqvist - Evaluated pulpal status after trauma. Cannot perpetuate without bacteria. |
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Split dam technique
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Two holes can be punched one for the clamped tooth and one for the tooth anterior to treatment tooth
- Cut dam in between with scissors - Place clamp on posterior tooth then stretch mesially to anterior tooth and held in place with wedjets cord, floss, or piece of dam |
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When to use split dam technique
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Insufficient tooth structure
Porcelain crowns Veneers |
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Restorative procedures to isolate severely broken down teeth
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Copper band
Orthodontic band Temporary crown - Can be cemented over the remaining natural crown to help retain clamp |
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Smear Layer
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- Created by us during instrumentation
- Composed of organic and inorganic material - Serves as nutrient source for residual bacteria and occludes dentinal tubules causing microleakage |
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Peters
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35% of root canal systems remain untouched by instruments
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Purpose of Irrigation
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- Lubrication and helps to keep debris in suspension
- Mechanically inaccessible areas - Digestion of tissue |
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Properties of an idea irrigant
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- Antibacterial
- Dissolves organic tissue - Lubricates canal - Removes smear layer - Non-toxic and non-allergenic to healthy tissue. |
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Appropriate and Inappropriate irrigants
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Appropriate
NaOCl - Sodium Hypochlorite EDTA CHX - Chlorhexidine MTAD - Doxycycline, citric acid, Tween 80 Q-mix Inappropriate Saline Sterile water Local Peroxide |
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NaOCl
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Antibacterial
Dissolves ORGANIC tissue - 6% full strength, 5.25% active - pH 12-13 - DOES NOT remove smear layer entirely |
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EDTA
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Chelating agent that works on inorganic materials
- pH 7 - Removed smear layer - Most effective when used with NaOCl |
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CHX
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Substantivity
- Does not remove smear layer and does not dissolve tissue - Produces a red percipitate PCA when mixed with NaOCl |
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Ways to increase efficacy
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Volume
Concentration Adding energy Replenishing solution Time of contact Surfactant Canal preparation |
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How to irrigate
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NaOCl during instrumentation
Evacuate EDTA for 1 min Evacuate NaOCl for 1 min Evacuate Sterile saline Dry |
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Three components of trigeminal pain system
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Detection
Processing Perception |
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Peripheral Sensitization
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Neuropeptides
Inflammatory mediators Allodynia - Painful response to normally nonpainful stimuli Hyperalgesia - Heightened response to painful stimuli |
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Sprouting
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C-fibers will physically produce additional terminals
- Intensifies peripheral sensitization and contributes to hyperalgesia |
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TTXr
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Tetrodotoxin resistant receptors
- Increased expression during periods of inflammation - Hinders ability of anesthetic |
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Processing of pain stimuli
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Action potential arrives at medullary dorsal horn of subnucleus caudalis
- May cause Hyperalgesia, Analgesia, Interpreted Second order neurons cross midline and project to the thalamus via trigeminothalamic tract |
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Non-narcotic Analgesics
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NSAIDS - COX-1 and 2 inhibitors
Acetaminophen - Possible action at COX-3 *NSAIDS are contraindicated in patients with peptic ulcers and asprin sensitivity |
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Opioid analgesics
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Activates Mu receptor mainly in CNS and inhibits transmission of nociceptive signals from trigeminal nucleus to higher brain regions. Decreased output
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Corticosteroids
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Inhibits formation of arachidonic acid by locking COX pathway
- Inhibits vasodilation and migration of PMNs |
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3D's of Pain management
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Diagnosis
Dental treatment Drugs |
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Prescription treatment plan
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Mild pain - NSAIDs or Acetaminophen
Moderate pain - NSAIDS/Acetaminophen combo Severe pain - NSAID/Acetaminophen/Opioid |
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Local anesthetic mechanism of action
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Blocks sodium channels by partitioning into two types
- Uncharged basic form that crosses cell membranes - Charged acidic form that binds to inner pore of the sodium channel |
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Lidocaine & mepivicaine
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2% Lidocaine is red with 13 maximum allowable carpules
3% Mepivicaine is Tan with 7 Maximum allowable carpules |
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Mandibular Anesthesia
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Failure of IAN block ranges from 35% for lateral incisor, to 60% for 1st premolar and 1st molar
All patients reported profound lip numbness. Therefore, lip numbness cannot be used to predict pulpal anesthesia |
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Mannitol
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Hyperosmotic sugar solution that is thought to temporarily disrupt the perineurium allowing anesthetic to gain entry
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Diagnostic measures used to locate canals
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- Multiple pretreatment radiographs
- Troughing grooves with ultrasonic tips - Staining the chamber floor with methylene blue dye - Performing sodium hypochlorite champagne bubble test |
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Lingual Shoulder
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Lingual shelf of dentin that extends from cingulum to a point 2mm apical to the orifice
- Use a safety tipped bur or Gates-Glidden bur - Should flare orifices so that they are continuous with the walls of the access prep |
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Boundary limitations
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- Look at bitewings to determine the M-D Boundary limitations
- Mesial boundary is usually a line connecting the mesial cusp tips. Rarely find pulp chambers beyond this point - Distal boundary for maxilla is oblique ridge. Line connecting central grooves for mandibular molars |
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Maxillary First Molar pulp anatomy
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- Pulp chamber is widest in B-L direction
- 4 pulp horns are present - Pulp chambers cervical outline form is rhomboid or teardrop in shape - MB angle is acute, DB angle is obtuse, and Palatal is right angled |
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Maxillary First molar roots
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Palatal root Longest and largest
- Can have 1-3 Canals - Often curves buccally at apical 1/3 - Flat and ribbon-like wider in the M-D direction DB root is conical and may have 1 or 2 canals - Oval at orifice and becomes round as it approaches apical 1/3 MB root can have 1-3 canals - Concavity on distal aspect of MB root - MB2 is generally located mesial or directly in a line between MB1 and palatal orifices - Ledge of dentin covers Mb-2 |
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Maxillary First molar access cavity
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Generally Rhomboid in shape
- Should not extend into mesial marginal ridge - Can invade mesial part of oblique ridge but should not penetrate through it |
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Maxillary second molar
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MB canal orifice is more mesial and buccal than 1st molar
DB orifice approaches mid-point between MB and P orifices |
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Mandibular 1st molar
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Trapezoid pulp chamber floor with 4 horns
- Mesial usually has 2 roots while Distal may have 2. DL root, if present, has an apical hook towards the buccal - Distal surface of mesial root and mesial surface of distal root have concavities that makes dentin wall thin - MB canal has greatest curvature esp in the BL direction |
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Types of Dentin
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Mantle - First formed dentin immediately subjacent to enamel or cementum
Circumpulpal - Formed after layer of mantle dentin Pre-dentin - Unmineralized matrix between odontoblasts that ultimately forms new dentin Developmental Primary dentin - Forms during tooth development Secondary dentin - Formed after root is fully developed Peritubular dentin - Lines dentinal tubules. Most calcified Intertubular dentin - Lies between peritubular dentin. Accounts for bulk |
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Dentinal tubules numbers and sizes
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Density of tubules are higher in coronal dentin and higher closer to pulp
Diameter of tubules decreases as you move away from pulp |
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Instrumentation pain
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Pulpal nerve fibers have potential to resist necrosis
- C fibers may be present in degenerating pulps - So instrumentation of non-vital teeth can cause pain |
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Pain pathway from tooth
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Maxilla - Ant/Mid/Post superior alveolar nerve -> V2 -> Trigeminal ganglion -> Synapse on Subnucleus Caudalis -> Secondary neurons travel via trigeminothalamic tract to thalamus -> Nerves project to cortex
Mandible IAN -> V3 -> Synapse on the medullary dorsal horn of the subnucleus caudalis -> Secondary neuron travels along trigeminothalamic tract to thalamus -> Nerves project to cortex |
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Throbbing pain
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Is a result of stretching of nociceptors surrounding pulpal vasculature due to heart contraction
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Benefits of Crown Down
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- Initiates cleaning from coronal to apical 1/3
- Gives full tactile awareness in apical 1/3 - Enhances irrigation efficiency - Minimizes pushing irritants into periradicular region |
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Hand files
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16mm of cutting flutes
- 3 diff lengths 21,25,31mm - Pink is 6 file - Grey is 8 file - Purple is 10 file - White 15 - Yellow 20 - RBGB - All hand file have a taper of 0.02mm |
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Stainless Steel Properties
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Corrosion resistant - Different grades
Separation resistant Flexible Biocompatible |
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Nickel Titanium
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Corrosion resistant
Strong More flexible than stainless steel Biocompatible Has shape memory More expensive than stainless steel |
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Objectives for access cavity preparations
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- Achieve straight line access
- Locate all canal orifices - Conserve sound tooth structure |
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How to make Apex locator more accurate
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- Connect probe after you turn it on so that it can calibrate correctly
- Steel Wool to remove oxidized layer - When battery strength gets below 50%, change the batteries |
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Rotary files types and colors
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Yellow - 20 Series
Blue - 30 Series Black - 40 Series - All have 0.10, 0.08, 0.06, and 0.04 tapers. Accessory files - Green 0.35 - Yellow 0.50 - Green 0.70 All have 0.12 taper Stopper colors - RGBYB - Red: 0.04 - Green: 0.06 - Blue: 0.08 - Yellow 0.10 - Black: 0.12 Accessory files |
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Antibiotics Prophylaxis
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Amoxicillin: 2g
Clindamycin: 600mg Azithromycin or Clarithromycin: 500mg |
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Virtucci canals
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1 Wein 1
21 Wein 2 121 2 Virtucci 4 is Wein 3 12 Virtucci 5 is Wein 4 212 1212 3 |
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Keys to avoid mistakes
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- Cusp tip to floor - 6mm
- Roof of chamber to floor - 2mm max, 1.5mm in mand - Floor to furcation - 3mm |
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Gates Glidden drills
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#1- 0.5mm
#2- 0.7mm etc - Usually when cutting with a gates glidden drill, you're cutting a hole minimum of 1 size larger |
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Access Sequence
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Penetration
Enlargement Refinement |
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Miller
Kakehashi Moeller Sundqvist |
Miller - Described association between bacterial and apical periodontitis. ID'd bacteria and showed that they area all different in each 1/3 of root
Kakehashi - Germ free rats Moeller - Monkeys Sundqvist - Humans |
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Ways to increase efficacy
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Volume
Concentration Time of contact Can add energy by heating it Surfactant |
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Mepivacaine
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3%
- No epi - Tan cartrige - 5.5 avg max dose |
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Reversing agent
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Phentolamine Mesylate
- aka Oraverse - 0.4mg per cartridge |
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Obturate to CDJ 0.5mm from apex
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Cutler
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Root rocator is 96% accurate
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Shabahang
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How to use root zx locator & tips
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- Has a port wire with 2 connectors. Lip clip and file clip
- Lip clip connects to white port and is attached to opposite side mandible. - File clip attaches to grey port and clips to the file to confirm WL using Stainless steel file - If battery is <50%, recharge battery - Use triple zero steel wool to clean off clip connector to keep it working well - Do not plug wire into port until unit is turned on. Otherwise will be calibrated to last patient |
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Hand and Rotary file lengths
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Handfile
- 21, 25, 31 Rotary - 17, 21, 25, 30 |
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Step back technique
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Coffae and Brilliant
- Go to working length with 1 size, then increase size and go to 1mm short of working length and continue - Time consuming, fatiguing, can get zips, strips, and ledges |
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Morgan
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Crown Down technique
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Length measurement after coronal enlargement
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Ibarola
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Canals avg 9-15mm from orifice to apex
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Cliff Ruddle
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Orifice is at level of CEJ
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Rankow
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Endo motors
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GT and plain pro-files run at 300rpm
- Except accessory files which run at 500 rpm |
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Objective of Obturation
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Seal from canal orifice to apical constriction all of the tissue spaces vacated by the preceding instrumentation and irrigation
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Obturation material requirements
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Easily inserted
Easily retrieved Flows readily Non toxic Dimensionally stable |
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Factors for Success of treatment
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Ingle myth: Success is directly related to obturation
Moller fact: Success of treatment is directly related to quality of shaping and cleaning Other factors: - Skill of operator - Materials and their use - Radiographic interpretation - Restoration of tooth and health of supporting periodontium |
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Why seal the canal
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- Create coronal and apical barrier
- Sequester remaining bacteria - Promote and preserve apical healing |
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Obturation methods
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Cold - Lateral condensation
Warm - Heat softened gutta percha. Warm lateral compaction, vertical compaction, continuous wave, thermo-mechanical Others - Pastes. Not often used, not accepted and may have arsenic |
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Ideal root canal
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- Filling of entire space as close as possible to CDJ
- Movement of little to no filling materials beyond tooth into PA tissues - Radiographically dense fill with absence of voids - Shape should reflect tapered funnel with same shape as external root shape |
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Phases of Gutta Percha
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Beta phase - Cold
Alpha phase - Heated phase. Sticky and flows. Can be compacted. - Sealer/cement is necessary. Acts as lubricant and makes gutta percha stick to dentin |
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Sealer at the school
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Thermaseal
- Resin sealer that has 2 parts of 50/50 mix - Compared to old sealers with eugenol |
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Contemporary sealers
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ZOE, Silicone, CaOH, Resin, etc
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Tugback
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Use master cone of gutta percha with same size and numbering of MAF
- When master cone binds at apical segment its good. But binding down all the way is not good |
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Cold compaction technique
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- Clean, shape, and disinfect
- Fit master cone with tug back to working length - Dry canals - Place minimal sealer on master cone - Place spreader in canal to resistance - D-11-T - Wiggle spreader back and forth 3 times before taking it out of canal - Clean spreader with alcohol to prevent sticking - Place accessory cone 20/02 in space provided by spreader - Repeat as necessary. - Sear off cones with heated instruments at the orifice - Condence with appropriate plugger |
