14 Endo Access

Question: Endo Access Prep

Answer: 1. Law of Symmetry

2. Law of Centrality

3. Law of Concentricity

4. Law of Color Change

5. 3 Laws of Orifice Location

==================================================

Question: The Laws of location of canal orifices

Answer: -Triangular outline form

-Middle 1/3 of Lingual Surface

-Removal of Lingual shelf for straight line access to the canal system

==================================================

Question: Maxillary Incisor Access Preps

Answer: -Ovoid in outline form

-Centered in the crown

==================================================

Question: Premolar Access Preps

Answer: -Triangular or Trapezoidal in outline form

-Confined to the mesial triangular pit and central fossa

==================================================

Question: Maxillary Molar Access Preps

Answer: -Ovoid in outline form

-Middle 1/3 of Lingual surface

==================================================

Question: Mandibular Incisor Access Preps

Answer: -Rectangular or Trapezoidal in outline form

-Outline form determined by canal anatomy

==================================================

Question: Mandibular Molar Access Preps

Answer: 1. Pulpal & Periradicular diagnosis

2. Evaluate for Restorability

3. Proper isolation

==================================================

Question: Tx Planning & Evaluation for Restorability

Answer: -Provides dry, clean, isolated field

-Protects pt from aspiration/swallowing risks (ie. instruments or operating materials)

-Reduces cross contamination risk

-Intraoral soft tissues retracted & protected

-Endo Standard of Care

==================================================

Question: Rubber Dam Utilization

Answer: Estimated Depth of Access that can be determined by:

-Superimpose highspeed handpiece & bur

-Digital radiograph measure feature

-Millimeter ruler

==================================================

Question: EDA

Answer: -Establish complete access for instrumentation

-Determined by size of chamber

-Determined by shape of chamber

-# & curvature of the canals

==================================================

Question: Outline Form

(Access Prep)

Answer: -Unobstructed access to the canal orifice

-Straight line access to all canals

==================================================

Question: Convenience Form

(Access Prep)

Answer: -Apical Constriction

-Apical Foramen

-True Apex

==================================================

Question: Working Length Determination

(Apical Canal Prep)

Answer: -The apical portion of the root canal having the narrowest diameter

-Position may vary but is usually 0.5-1.0mm short of the center of the apical foramen

==================================================

Question: Apical Constriction

Answer: The main apical opening of the root canal

==================================================

Question: Apical Foramen

Answer: The tip or end of the root as determined morphologically (anatomic apex), or radiographically (radiographic apex)

==================================================

Question: True Apex

Answer: An electronic instrument used to assist in determining the root canal working length or perforation

-Operates on the principles of resistance, frequency or impedance

==================================================

Question: Root ZX Apex Locator

Answer: -A technique where the apical portion of the canal is maintained free of debris by recapitulation with a small file through the apical foramen

-Initial canal negotiation establishes canal patency with a small diameter hand file

-Recapitulation

==================================================

Question: Apical Patency

Answer: -The distance from a coronal reference point at which canal preparation and obturation should terminate

==================================================

Question: Working Length

Answer: -Establish a glide-path in each canal to a #20/.02 hand file to working length

-Enhances file centering ability of handfiles and engine driven instruments

==================================================

Question: Glide Path

Answer: -Variable

-Master apical file

==================================================

Question: Degree of Apical Enlargement

Answer: The largest file used to the full working length of the completely prepared root canal

==================================================

Question: Master Apical File

Answer: -Chemomechanical Debridement

-Hand files & Engine driven instruments

-Irrigants

-Root canal systems must be cleaned & shaped — cleaned of their organic remnants and shaped to receive a 3AD hemetic filling of the entire root canal space

-Accessibility of the contaminated root canal areas is key to disinfecting efficacy

==================================================

Question: Cleaning & Shaping

Answer: Use of chemicals for irrigation of the root canal, demineralization of dentin, dissolution of pulp tissues and neutralization of bacterial products and toxins

-Used in conjunction with biomechanicalprep (use of rotary and/or hand instruments to expose, clean, enlarge & shape the pulp canal space)

==================================================

Question: Chemomechanical Debridement

Answer: -To adhere to biologic principles regarding the extent of radicular preparation into the root canal system and understanding that complete removal of pulpal remnants will increase endo success

==================================================

Question: Biomechanical instrumentation

Answer: -Avoid instrument separation

-Unwinding of the flutes

-Prevention is key!!

-Straight line access

-Coronal preflaring

==================================================

Question: Profile NiTi Instruments

Answer: 1. Pluggers

2. Spreaders

==================================================

Question: Engine Driven Instruments

Answer: -Vertical Condensation

-Heat transfer

==================================================

Question: Instruments for Obturation

Answer: -Lateral Condensation

==================================================

Question: Pluggers

Answer: -Hold, arrange & clean small instruments

-Ideal for files, pluggers and spreaders

-Antibacterial polyurethane foam

-Saves time

-Built in ruler

-Medicaments

==================================================

Question: Spreaders

Answer: -NaOCl irrigant of choice

-Passive irrigation

-Side venting needle

==================================================

Question: Endo Foam Sponge Organizer

Answer: -NaOCl

-5.25%

Clorox or liquid shock

==================================================

Question: Irrigation Syringe

Answer: -Mechanical flushing of debris

-Dissolves vital & necrotic tissue

-Antimicrobial action

-Readily available

-Inexpensive

==================================================

Question: Irrigation

Answer: -Facilitate file manipulation

-Aid in initial canal negotiation

-Reduce tortional forces

-Composed of EDTA, Urea Peroxide & Propylene glycol in a base of Carbowax

-Effervescent effect of NaOCl and Urea peroxide

-Removes inorganic ions from tooth structure

-Lubricates, emulsifies and holds debris in suspension

==================================================

Question: Passive Irrigation

Answer: -Easily introduced into the canal

-Seal canal laterally & apically

-No shrinkage after insertion

-Impervious to moisture

-Bacteriocidal or discourage bacterial growth

-Radiopaque

-Not stain tooth structure

-Non irritating to periapical tissues or affect the tooth structure

-Be sterile or easily sterilized

-Be easily removed from the root canal system

==================================================

Question: Canal Lubricants

Answer: 1. Master Apical File

2. Master Apical Cone

3. Placement verified by radiograph

4. Master Apical Cone & spreader placement

5. Accessory cone placement

6. Process repeated

7. Cones removed at orifice with heat & vertically compacted

8. Remaining canals are obturated in same manner

-Final radiograph with canals properly obturated

==================================================

Question: Desirable Properties of Obturating Materials

Answer: Canal obturation may be delayed for 1+ visits after prep to give time for medicaments sealed into the canals to reduce or eliminate the microbial population and for the pts signs (especially in complex cases)

-Pt symptoms?

-Pulp & Periradicular status?

-Degree of difficulty?

-Number of appts?

Teeth with little or no problems can be prepared & filled in 1 appt

==================================================

Question: Lateral Compaction

(Obturation)

Answer: Conclusion:

-Success based on periapical health associated with roots following 1 RCTx (83%) or 2 RCTx (80%) was similar, wit h10 factors having a common effect on both, whilst the 11th factor (EDTA as an additional irrigant) had different effects on the 2 txs

==================================================