Quiz 2 Flashcards
(32 cards)
What are the two fundamental principles of a root canal preparation and what do they mean?
- CLEANSE: Remove the canal contents, specifically infective microorganisms and necrotic or diseased tissue.
- SHAPE: Enlarge the natural canal space enough to facilitate medicaments and obturation.
What are the five universal principles of canal preparation?
I. Continuously tapering funnel from the apex to the access cavity.
II. Cross-sectional diameter should be narrower at every point apically.
III. The root canal preparation should flow with the shape of the original canal.
IV. The apical foramen should remain in its original position.
V. The apical opening should be kept as small as practical.
What are the four Biologic Objectives of Instrumentation?
- Confinement of instrumentation to the roots themselves
- No forcing of necrotic debris beyond the foramen
- Removal of all tissue from the root canal space.
- Creation of sufficient space for intra-canal medicaments
What are the 3 steps of Straight-Line Access?
- Find the Canal
- Negotiate, Explorer, Smooth
- Pre-Flare Coronal Canal
What are used to aid in the Apical Configuration Patency and Working Length?
TEX:
- Tactile Feel
- Electronic Apex Locator
- X -Ray Radiograph
What is it called when you go from small instruments to large and then large down to small to clean out the pulpal canal through the Glide Path?
- Step-Back Progressive
What is the technique used to take slow circular movements to debride the root? This is used for Mid-Root preparation along with what other technique?
- Balance Force Technique
- Crown-Down Technique
During an Apical Preparation, what two steps are used?
- Step-Back Progressive technique with hand files
- Rotary instrumentation
The Cutting Edges on a file are the positive or negative Rake Angles that cause chips in the dentin, what makes them different? What are the three things determine the size and shape of the dentin chips produced?
- Negative Rake Angle: Won’t take off any if in a forward direction.
- Positive Rake Angle: Will take off the most dentin.
- Rake angle, sharpness of blade, force applied.
What is the Rake Angles on a K-file? Hedstrom?
- K-File: Neutral/Slightly Negative rake angles.
- Hedstrom: Positive rake angles.
What generates the Force and Direction of the file to engage the canal wall from a manual hand filing standpoint and from a mechanical rotary filing standpoint, and what is the general shape of the cut?
- Manual hand filing: Clinician directed force, oval.
- Mechanical rotary filing: Taper of the file against the canal walls, circular.
Straight- Line Filing, Linear filing, Filing, Filing Circumferential, and Filing Scraping are examples of what? Clock-wise, Counter Clock-wise, Watch-winding, Reciprocating (back’n forth) Rotary are examples of what? What are the names of the combination of the two?
- Up/Down movement of cleaning the canal.
- Round ‘n Round movement of cleaning the canal.
- Balance Force and ¼ Turn ‘n Pull
What is the rotating clockwise as flutes engage dentin and what instruments are used for this? What is the binding of flutes and scraping out along dentinal walls and what instruments are used for this? What is moving the file from wall to wall while scraping and what instruments are used for this? What is placing, cut w/pressure (force) and remove and what instruments are used for this? What is the gently and repeatedly rotating instruments apically and what instruments are used for this?
- Reaming (REAMER, ROTARY)
- Filing (K-FILES, HEDSTROM FILES)
- Circumferential Filing (ALL but REAMERS)
- Balanced Force (K-FILES, REAMERS)
- Watch Winding/Twiddling (ALL)
Be able to locate and label the following on a picture: Apical Constriction, Minor Apical Diameter, Major Apical Diameter, and Apical Foramen?
- SLIDE 33
What is the unobstructed path from orifice to the terminus, this preparation defines the natural canal, has smooth walls and removes all or most of the pulp tissue?
- Glide Path
What are the 4 routes of Root Canal Infection?
- Dentinal Tubules: Smallest tubules are bigger than largest bacteria (.2 to .7 microns), invasion is more rapid in non-vital teeth.
- Direct Pulp Exposure
- Periodontal Disease (biofilms)
- Anachoresis (attraction of bacteria to an area)
Why is bacterial invasion more rapid in non-vital teeth than vital teeth?
- Outward flow of fluid, sclerosis of dentin beneath a carious lesion, reparative or reactionary dentin, smear layer, host defense molecules, impede bacteria, progression to the pulp.
What are the Microbes of Dental Decay? What are the Microbes of Periodontal Disease? What are the Microbes of Periapical Diseased Tissue? What are Microbes in Root Canal Treated Teeth?
- Dental Decay: Strep. Mutans
- Periodontal Disease: Gram-negative anaerobes.
- Periapical Diseased Tissue: Gram-positive
- Root Canal Treated Teeth: Enterococcus Faecalis (gram positive anaerobe)
What is a multicellular microbial community characterized by cells that are firmly attached to a surface and enmeshed in a self-produced matrix of extracellular polymeric substances (EPS)? Where are these located? What advantages does this have?
- Biofilm
- On the canal wall, lateral canals, apex of the root. **(larger periodontal lesion=higher prevalence of biofilms in apical canal)
- Improved communication, metabolic cooperation, protection from external threats.
What are simple-cells that float in a liquid medium (necrotic canal)? How can these be eliminated?
- Planktonic Microorganisms
- Can be eliminated with instruments and irrigants during treatment.
What are the 6 ideal properties of Irrigants? What is their general use? What is the general way to use Irrigants?
● Organictissuesolvent ● Inorganictissuesolvent ● Antimicrobialaction ● Nontoxic ● LowSurfacetension ● Lubricant - Use for Lavage, flushing debris, killing bacteria, softening dentin, chelation and lubrication of filing. - Syringe placement, agitation, sonic, ultrasonic activation.
How does Sodium Hypochlorite (NaOCl) work? Advantages? How to use? Precautions?
- Irrigant: Dissolves vital and necrotic tissue (inorganic tissues, soft tissues)
- Antimicrobial action, lubricating action and inexpensive.
- Concentration of .5-5.25% (toxicity decreases below 2.5%)
- Extrusion into the apical tissues can cause major tissue damage.
How does Ethylenediaminetetraacetic Acid (EDTA) work? Advantages?
- Irrigant: Works to remove inorganic components (hard tissue, enamel,calcification) and does not hurt organic tissues.
- Advantages: Demineralization/active removal of smear layer
How does Chlorhexidine (CHx) work? Advantages? Disadvantage?
- Irrigant: Has a broad-spectrum antimicrobial action.
- 2% kills bacteria as effectively as 5.25% Sodium hypochlorite.. Is very effective against Entero. Faecalis. Good in combination with NaOCl.
- Doest not remove smear layer.
