endo Flashcards
what is stochastic effects of radiation?
there is no threshold dose below which stochastic effects do not occur and that the probability of experiencing these effects is proportional to the dose of radiation absorbed
(EDTA) full name +MOA
[ ] EDTA and duration before final rinse with… (with [ ]) ?
disadv
Role of Chelating and Decalcifying Agents [EDTA]
Ethylenediamine Tetraacetic Acid
removal of smear layer + enlargement of dentinal tubule [inorganic components, leaves organic tissue intact- thus NaOCL is necessary]
17% EDTA-1minute then->final rinse-NaOCl
Concentration ranges from 0.5% to 5.25%, with a common concentration being 2.5% to decrease potential toxicity while maintaining tissue dissolving and antimicrobial activity.
> 10mins - excessive removal of periTub. + intratubular dentine
1 Smear Layer Removal: improving canal cleanliness.
2 Enhancing Irrigation: - increase the efficacy of irrigants in disinfecting the root canal system.
3 Prevent apical compaction of debris.
4 Facilitating Obturation: The removal of the smear layer and opening of tubules allow for better adaptation of obturation materials and potentially stronger bonding of sealers.
pARAchloroaniLINE [PCA]- what is it?So what?
now what mx?
formation of insoluble brownish precipitate when NaOCL and CHX are combined in RCS.
Interfere with seal of obturation.
Mx: by drying canal with paper points or using saline as intermediate irrigant
NaOCL mechanism of action
-mechanical fx
-chemical action… by breaking down…
Adv4x
Disadv
mechanical flushing of debri out of canal and dissolves vital and necrotic tissue by breaking down proteins into amino acids.
Adv - 1 Antimicrobial, 2 lubricant by mechanical flushing debri 3 inexpensive 4 easily available
Disadv- hight toxic- must avoid extrusion
main Aims of Access Cavity Preparation: 5x
1 Remove all caries and defective restorations.
2 Locate and gain direct access to all root canal orifices.
3 Debride the pulp chamber (remove chamber roof and all coronal pulp tissue)- outline form.
4 Conserve tooth structure
5 Creates straight line access of instruments to apical 1/3 of the root; instrumentation and disinfection+ reduce procedural errors
Objectives of Access Cavity Preparation:
Biological Objectives: 2x
Mechanical Objectives: 6x
Biological Objectives:
1aRemove all infected material and caries.
2b Facilitate a good coronal seal to guard against oral contaminants.
Mechanical Objectives:
1Locate the pulp chamber and root canal orifices.
2 Ensure ease of operation and convenience for the operator.
3 Create an ideal outline form: Include the whole pulp chamber, avoiding overextension to conserve tooth structure.
4 Remove the roof of the pulp chamber and pulp horns.
5 St line access + smooth and gradually flare canal walls for effective debris removal and instrument placement.
6 Avoid procedural errors - ledging, transportation and perforation.
Anticurvature Filing
vs
Circumferential
Filing
used during coronal flaring- preserve furcal wall
Selectively removes dentine on bulky wall
+protecting inner furcal wall and coronal to the curvature- prevent strip perforation
vs
file is placed and withdrawn in a directional
manner sequentially [m,b,d,l]- lower incisors
Smear LayerComposition… that accumulate on..
Contamination:
Importance of Removal Before Obturation:
2x
organic pulpal materials and inorganic dental debris that accumulate on radicular canal wall
Contaminated with bacteria and metabolic by-products.
1Prevents sealer contact with canal wall.
2Used as a substrate for sustained growth of any microorganisms still in the dental tubules.
zipping is …
zipping is procedural error with apical transportation in curved canal+ shape of the canal is altered at the apex [elbow-zip formation],
torsional fatigue dt… and ….
cyclic fatigue -….
binding of file to canal - breakage of file at the tip
didnt bind - keep rotating and break over time
Apical Transportation …
inadvertent redirection of the canal’s natural path to a new location on the external root surface,
a result of instrumenting beyond the natural terminus of the canal.
H-type files knwn as…
feature: ……angle of blade edge and … of flute makes it…
usage limitation: only cuts on …. and used for …
not suitable for …. actions bcz can cause instruments to …
primary use- 3x
risk 2x
Hedstrom Files
Features: wide angle of the blade edge
depth of the flute -> sharpest files.
Usage Limitation: Only cuts on withdrawal and is exclusively for filing; not suitable for reaming or rotating actions as these can cause instrument fracture.
Primary Uses:
Filing dentinal walls.
Differentiating canal paths in multi-rooted teeth on radiographs (used alongside K-files).
Removing gutta-percha during retreatment/post preparation.
Risks:
Thoughtless insertion can lead to apical ledging.
Excessive filing may result in mid-root perforation.
Gold Standard for Endodontic Obturation materials
list types of materials
Advantages first option: 5x PMRLtS
Gutta-Percha > silver pts
1 Plasticity: Adapts well to irregularities in prepared canals when compacted.
2 Manipulation: easy to handle and manipulate for complex obturation techniques.
3 Removability: Can be partially or totally removed from the canal for post placement or retreatment.
4 Low Toxicity and is nearly inert when in contact with connective tissue.
5 Sterilization: Self-sterilizing properties; does not support bacterial growth. Contaminated cones can be sterilized predictably with 1% or greater sodium hypochlorite for 1 minute.
Disadvantages: gp 3X
HOW TO OVERCOME?
1 Adhesion: Lacks adhesion to dentin.
2 Elasticity: Slight rebound effect, which may cause pulling away from canal walls.
3 Shrinkage: GP shrinks upon cooling.
Marked shrinkage when mixed w/- chloroform[solvent].
Sealer Use:
Purpose: Fills and seals gap between the GP cones and between GP and the canal wall.
reciprocal induction in tooth formation..
reciprocal induction IEE release GF to [dental papilla] pulp cells to dy/dx to odontoblast-> dentine-> +IEE chg to ameloblast->enamel
[enamel] Epithelial-mesenchymal [dentine] interactions core processes of tooth formation
pharmacological methods other than LA
rely on… medication to decrease…3x
eg..
Pre emptive analgesia 1hr prior to procedure
adjunctive medication to decrease anxiety and response to potentially painful stimuli
during tx and ensure have better experience.
Eg. inhalation Nitrous oxide, oral BZD (eg. Triazolam has fast onset and relatively short T1/2,
lipophilic in nature and can be given sublingually for rapid absorption)- adults/ iv sedation Midazolam
Trephination, ie…… by ….. and is [indicated or CI?] post pulpectomy
artificial fisulation by creating an opening through mucosa and bone is not useful and Contraindicated
MEDICATION POST OP ANALGESICS FOR ENDO
ibuprofen 400mg 4X/day. First dose taken
before loss of LA -> by the clock 6hrly -> PRN
If severe pain, take 650-1000mg of paracetamol b/n
doses of ibuprofen (synergistic effect)
If NSAID CI, PCM 1g 4x/day and 60mg codeine
3x diff dx of pain on biting- what method to test?
Tooth Slooth/Wedge test used to differentiate a cracked tooth from fractured cusp/ split tooth
1 Cracked tooth: no movement (Torabinejad: positive
pain on release of biting force)
2 Fractured cusp: will break off under slight pressure
with no further mobility
3 Split tooth: mobility that extends below the CEJ
Prevention of propagation of cracked tooth with 3X
Removal of pulpal symptoms with cracked tooth Happens when 3x
1Orthodontic band
2 occlusal adjst to remove occl forces
3 Provisional crown
1 Often cuspal protection provides relief
2 occl adjstmt
3 If necessary, pulp extirpation/ rct
root end surgery/apicectomy is ….grade tx VS ….GRADE in Re-RCT
retrograde vs orthograde in RE-RCT
blocked canal mx:
prevention:
Do not increase force on the file as it may lead to ledge formation or instrumentation separation
-Attempt negotiation with RC prep
Practice recapitulation between each successive enlarging instrument regardless of the C&S
technique (ie, taking a smaller file to correct WL to loosen accumulation debris followed by flushing
with 1-2ml of irrigant)
Avoid compaction of tissue at apical end
RC prep made of…. helps…
glycol, urea peroxide and EDTA in a special water-soluble base
helps remove calcifications and lubricates canal
ferrule effect: important to preserve…. and … to create…. for..
… -… mm +ve effect on … resistance.
thickness of dentinal walls…. mm [minimum]
incomplete vs complete lack
no coronal structure…mx by
Preserving sound coronal and radicular tooth structure to create a ferrule effect is crucial for longevity of restored teeth.
1.5- to 2-mm of ferrule has a positive effect
on fracture resistance. Residual dentinal walls are expected to be at least 1mm thick. An incomplete ferrule is considered to be a better
option than a complete lack of ferrule.
In teeth with no coronal structure orthodontic extrusion should be considered rather than surgical crown lengthening.
Biologic Width is
do not… to ….
This distance can be
corrected with
distance from the depth of the gingival sulcus to the crest of the bone (relatively constant 2.04 mm*) JE 0.97mm; CT attachment =1.07mm.
violate to prevent chronic inflammation, attachment loss, or bone loss, which is
one of the keys for tooth and dental
restoration longevity
crown lengthening/ gingivectomy or
orthodontic extrusion. * Schmidt et al 2013; JClinPerio
post characteristics 3x
Post diameter should be minimal and <1/3 of the root diameter
Tapered post prep prevents the risk of creating a step at the apical post space but may
predispose to wedging and root fracture
Parallel posts provide greater retention than tapered posts and do not wedge
Cause Extrusion in Endodontics 2x
s/s 2x + 1x
1 Forceful Expression: Usually involves sodium hypochlorite, Irrigants can penetrate periapicular tissues.
2 Needle Positioning: Can occur from wedging the needle in the canal or out a perforation.
Symptoms/Signs (S/S):
1 Pain:Sudden,prolonged,+ sharp pain/ discomfort
2 Swelling: Rapid, diffuse swelling following the incident.
3 Potentially life-threatening due to cytotoxicity.
Prevention extrusion:
1 Needle Placement+depth: Use loose placement of irrigating needle, short of WL+Rubber stop; x bind
2 Irrigation Technique: Employ careful irrigation with light pressure; m/m to Agitate irrigant. endoactivator hand held sonic / ultrasonic …
3 Equipment: Use a perforated needle with a side port and rounded tip to minimize risk.
4 CBCT if see IADN is near to apices of roots -lower7’s - consider to refer
Management (Mx) NaOL accident: 3
- Initial management to alleviate symptoms. Analgesics and possibly antibiotics.
2 Patient Reassurance
3 Follow-Up: Recall to observe and monitor the patient’s recovery. / kiv referral
Intraappointment Emergencies: Causative iatrogenic Factors6x and host factors4x
factors reduce flare up incidence 2x
post tx/ undected crack
- Irritants within the Pulp System: Bacteria and by-products/ Necrotic pulp tissue- Inadequate Debridement of the canal.// LEAKY TD
- Operator-Controlled (Iatrogenic) Factors: MIOE
2i Missed canals/complex RCS
2ii. IC medication not used b/n visits
2iii OCC-Hyperocclusion in the temporary restoration.
2iv Extrusion -bacteria BEYOND apex.
2v extrusion use of intra-canal irrigants/ medicaments[Nicolau syndrome-purplish discolouration]. - Host Factors Influencing Emergencies
Pain History: with preoperative pain are more likely to experience a flare-up.
PA Pathology initially
Tx History: Retreated teeth show a higher incidence of flare-ups.
Systemic Health: Patients with allergies report higher flare-up rates. - factors that reduce flare ups
Presence of a sinus tract decreases the incidence of flare-up.Lower incidence in mandibular teeth.
qs to ask to know emergency or not 8x
disrupt [qof life -daily activities]; duration -hrs or days; drugs taken-any relief; then ; location, onset, aggravating factors/reliefing factors; character [describe sharp, dull etc]; feverish/malaise?
manage this endo emergency:
pain reflief
clinical evaluation
tx revision
f/up and completion
education
-
Immediate Pain Relief:
- Prescribe appropriate analgesics to manage the pain. Non-steroidal anti-inflammatory drugs (NSAIDs), ibuprofen 400mg qds PRN//with pcm 1g -synergistic effect are usually effective but consider the patient’s medical history.
- If possible, see the patient as soon as possible for clinical evaluation.
-
Clinical Evaluation:
- Perform a thorough clinical examination including percussion, palpation, and mobility tests to assess the severity and extent of the inflammation or infection.
- Re-evaluate the tooth with radiographic examination to assess any changes since the last visit, such as signs of periapical radiopacity indicating extrusion/PARL
-REASSURANCE
-
Treatment Revision:
- Under appropriate local anesthesia- long acting marcaine, reopen the tooth to relieve pressure from gases/exudates accumulated inside the pulp chamber or canal.
- Carefully clean and irrigate the canal using sodium hypochlorite or another suitable irrigation solution to reduce microbial load. Use minimal instrumentation to avoid further irritation.
- If significant over-instrumentation or a procedural accident (like a perforation) is identified, address it accordingly with appropriate materials MTA.
- Apply an intracanal medicament with antimicrobial properties, such as calcium hydroxide, to help reduce inflammation and bacterial levels.
- Temporarily seal the tooth to prevent bacterial ingress.
-
Follow-up and Completion:
- Schedule a follow-up visit in a few days to reassess pain and inflammation. If the symptoms have subsided, proceed with the next steps of endodontic treatment, such as obturation (filling of the canal).
- Educate the patient on signs of worsening conditions and ensure she understands when to seek immediate care.
-
Patient Education and Prevention:
- Explain to the patient the importance of following post-operative instructions, including oral hygiene practices and avoiding chewing on the affected side to prevent further irritation or injury.
- Discuss the prognosis of the tooth and possible outcomes of the treatment to set realistic expectations.
INTERNAL INFLAMMATORY ROOT RESORPTION
alteration of Rdgphc… angle area is in …. rshlp…
vs EXTERNAL INFLAMMATORY ROOT RESORPTION
horizontal angle
constant relationship to pulp space
vs
with external resorption the
Rlucent area shift with diff angle of Xray taken
Pulp Obliteration Overview
Incidence: Common In: 4x
visible on radiographs as early as …
Appearance:… discoloration dt
Etiology:
1Teeth with an open apex (>0.7mm radiographically).
2 Teeth that have undergone extrusive/lateral luxation injuries and have been rigidly splinted.
Detection: Usually visible on radiographs as early as 3-12 months post-injury.
Yellowish-brown discoloration due to thickened and less translucent coronal dentine.
Etiology: not fully understood. Likely a consequence of nerve supply damage leading to uncontrolled reparative dentine production.
OR Blood clot formation in the pulp post-injury create a nidus for calcification if the pulp remains vital.