Description
In this collection we will review many important informations for dental students
Study Set Content:
Endodontics
Course Review
Enoch Ng, DDS 2014
-
Apexification
o
Induce calcified barrier in root with open apex for tooth with necrotic pulp
o
Often blunting of root end with little/no length increase
o
Clean/shape tooth and remove debris to create favourable environment for forming barrier
Use CaOH to induce hard tissue to help prevent overfill
o
Indications
Necrotic tooth with open apex
Compliant patient willing to return for multiple appointments
Restorable tooth
o
Technique
Rubber dam, local anesthesia
Access – large to accommodate larger instruments
Length determination from radiographs
Irrigation with NaOCl
Ca(OH)
2
delivered to working length
Lasting provisional with excellent seal
Recall patient every 3 months to wash out Ca(OH)
2
and inspect calcified barrier
Treatment may take 9-24 months
Obturate with gutta percha, permanent coronal restoration
o
Apical barrier
Blockage of apical foramen, may be an induced hard tissue or artificial material
May use single visit and create barrier with MTA
-
Revascularization
o
Promote revascularization of immature permanent tooth with infected necrotic pulp and apical
periodontitis or abscess – remove pathosis and induce angiogenesis in canal
o
Minimal/no mechanical instrumentation
o
Copious antiseptic irrigation of canals with disinfection by triple antibiotic
Has been shown radiographically to induce increased canal wall thickening via hard tissue and
continued root development
o
Indications
Same as apexification
Endodontics
Course Review
Enoch Ng, DDS 2014
o
Technique
Visit 1
Local anesthetic, rubber dam
Remove caries
Careful determination of radiographic working length
Irrigation with NaOCl – little/no instrumentation of the walls
Placement of antibiotic paste
Coronal seal with cavit/irm
Visit 2
Local anesthetic, rubber dam
Irrigate with NaOCl, rinse sterile saline
Dry canals with paper points
Induce bleeding with file beyond WL
Place moist cotton pellet below CEJ to induce clotting
Place MTA against clot, seal with glass ionomer, place final restoration
Objectives of vital permanent tooth with incomplete root growth
-
Maintain vitality, allow completion of root growth
-
Increased dentin wall formation
Summary
-
Reversible Pulpitis
o
Indirect pulp cap
o
Direct pulp cap
o
Pulpotomy
-
Necrosis
o
Open apex
Revascularization, revitalization
Apexification
o
Closed
Pulpectomy
Endodontics
Course Review
Enoch Ng, DDS 2014
Temporization, Restoration, Internal Bleaching
Intracanal Medicaments
o
Ca(OH)
2
Intra-appointment canal dressing
High pH inhibits bacterial growth, deactivates toxins
Supports apical healing
Prevents re-infection
o
Calasept, pulpdent, vitapex, ultracal
-
Place after instrumented to WL, place tip 1-2mm short of WL
-
Do not place in wet canal, do not bind tip, practice before depositing in canal
Temporary Restoration
-
Obtain fluid tight seal, maintain occlusal and proximal contacts
Cavit
-
Slight expansion (seals margins)
o
Water absorption, expansion
-
Non-vital teeth only
-
Class I preps
-
Minimum thickness 3.5mm for seal
-
Seal lasts <3 weeks
IRM
-
ZnO powder mixed with eugenol
o
Better compressive strength
o
Antimicrobial properties
-
Marginal ridges not intact
-
Long than 3 weeks if used as part of “double seal”
-
Procedure
o
Final NaOCl rinse
o
Dry canals with paper points
o
Place Ca(OH)
2
o
Place small dry cotton pellet
o
Place double seal temporary restoration, use incremental (not blog) technique
-
RMGIC – Fuji
o
Long term temporization
o
Expensive, rebuild areas to control coronal leakage prior to treatment
o
Remove caries
matrix band
place cotton pellet
place fuji
light cure
adjust occlusion
Restorations of Endo Treated Teeth
-
Protect from fracture, prevent reinfection, replace missing structure
-
Placement of final restoration is FINAL STEP in RCT
-
Biggest factor of long term prognosis = remaining dentin amount
o
No restorative material can substitute for intact dentin
o
Is tooth restorable? Determine before RCT
o
Anterior – <½ residual tooth or remaining walls <1mm on ¾ of tooth circumference, need post and core
o
Posterior – walls >3-4mm from chamber floor, >1.5-2mm thick only need core, <60% tooth left = post
-
Successful debridement and apical sealing essential for restoration of non-vital tooth
-
Sealing of coronal restoration vital to long term tooth health
o
97% of endo treated teeth retained after 8 years
o
85% of failed teeth did not have proper final restoration
Endodontics
Course Review
Enoch Ng, DDS 2014
Effect of NSRCT on Dentin
-
Pulpless = 9% less moisture, does not lead to progressive changes in biomechanical dentin properties
-
Insignificant changes to punch shear strength, load to fracture, toughness
-
Slight changes to microhardness
-
Nonvital dentin NOT more brittle than vital dentin
o
Cumulative loss of tooth structure from caries, trauma, restoration, endo procedure more critical
o
Strength of dentin directly related to remaining dentin within root and coronal structure
-
Intact tooth able to deform under loads – physiologic loading causes deformation with complete elastic recovery
o
Loss of central core of tooth structure = elastic recovery doesn’t take place
-
Access prep
o
Reduces tooth stiffness 5%
o
MOD prep (loss of marginal ridges) – reduces tooth stiffness 60%
o
Loss of inner cuspal slopes that unite/support tooth increases potential fracture
-
Well-constructed coronal restoration as important as obturation
o
Full cuspal coverage, partial coverage
o
Amalgam, composite resin
o
Glass ionomer – not for occlusal restorations
Restorations
-
Posterior RCT tooth with cuspal coverage
o
5mm sound tooth structure from crest of bone to tooth margin
2mm ferrule (prevent tooth fracture), 3mm biologic width
-
Previous Crown with occlusal access
o
Amalgam, composite
-
Caries
o
Amalgam, composite
-
Composite Restorations (tooth with porcelain crown)
o
Etch porcelain with 10% HF for 1 min, rinse
o
Etch dentin with 37% phosphoric acid 15-20s, rinse
o
Dry, apply silane, prime and bond, light cure
o
Place flowable composite, place composite incrementally (2mm), light cure
o
Finish and polish, adjust occlusion
-
Amalgam coronal-radicular restoration
o
2mm amalgam placed into each canal and through pulp chamber
o
Requires crown coverage
o
After 4 years, 0% failure
Intracoronal Barriers
-
Gutta percha exposure can be completely contaminated within 3 days
-
Retreat if gutta percha exposed >30 days
-
Orifice barriers vital to long term success
o
Countersink orifice with System B
o
Clean orifices/pulpal floor with ^OH
o
Place temp/permanent orifice barrier over orifices and pulpal floor
o
1-2mm glass ionomer significantly reduces microleakage
Endodontics
Course Review
Enoch Ng, DDS 2014
Posts
-
Aid in retention of core/restoration
-
Weaken tooth structure (loss of dentin) – they do NOT strengthen tooth
-
Increases likelihood of tooth fracture and perforation
-
Post length = crown height, or ½ root length
-
Remove gutta percha with heated instrument
-
No post has achieved fluid tight seal – 5mm gutta percha should remain for apical seal
-
Use smallest post possible – 1.5mm dentin surrounding post on all sides
-
Knowledge of root anatomy essential for successful post placement
o
Mx incisors – sufficient bulk to support post
o
Mx canines – wide facial/lingually
o
Mx premolars – roots curve distally, taper rapidly, buccal root has canal invagination 83%
Place post in palatal canal
o
Mx molars – 85% palatal canals curve facially
Not visible radiographically, but invaginations on facial aspect of palatal canal
o
Mn incisors – higher success without post/core, thin mesial/distally
Invaginations common, multiple roots common
o
Mn premolars – lingual inclination of roots (caution for facial perforations)
o
Mn molars – roots thin mesial/distally, invaginations are common, danger zone
Place post in distal canal
-
Success rate
o
Anteriors – no advantage for coronal coverage – composites work equally well
o
Posteriors – no advantage for posts – coronal coverage increases success rate
o
Exception – RPD patients
-
Types of Posts
o
Threaded – most retentive, causes root fracture
o
Tapered – least retentive, most dentin conservative
o
Parallel – middle ground
o
Bonded fiber – conservative prep, 1 visit placement
Post length can be conservative, bond aids in retention/seal
Favorable fractures
Isolation with rubber dam still needed
o
Cast posts
Impossible to exclude bacteria during temporization period
Unfavorable fractures
Fabrication nearly impossible while maintaining isolation
Posts Summary
-
Case selection – know anatomy, keep dentin removal to minimum, anticipate potential complications
-
Posts should be reserved for limited clinical scenarios
-
Bonded fiber posts under RDI is preferred
Restoration Summary
-
Rubber dam isolation, conservative tooth structure removal
-
Intact anteriors don’t need a crown (can use composite), but posteriors do require cuspal coverage
Endodontics
Course Review
Enoch Ng, DDS 2014
Internal Bleaching
-
2 types of discolorations
o
Extrinsic – arising in enamel – coffee, tea, wine, etc
Can be removed via prophy or external bleaching
o
Intrinsic – originating within pulp chamber/dentin – pulp degeneration causing hemoglobin breakdown
Causes
Pulpal degeneration
Caries
Systemic drugs
Sealer/gutta percha
Bleaching Materials
HOOH – 5-35%
Carbamide peroxide – 10-15%
Sodium perborate – powder mixed with HOOH or H
2
O
-
Walking Bleach Technique
o
Realistic expectations – inform patient desired shade may not be achieved
o
Take pre-op shade
o
Rubber dam isolation
o
Remove restoration and pulp horns, don’t remove excess dentin
o
Remove 3mm GP apical to CEJ, remove remaining sealer with ^OH/CP
o
Place 2-3mm barrier – Cavit, IRM, GI, or composite
Looks like a bobsled run/ski slope
Gutta Percha is NOT effective barrier to bleaching agent
o
Mix sodium perborate with distilled water or anesthetic
o
Place with amalgam carrier, place temporary
o
Recall every 7-14 days, if unsatisfactory repeat procedure (short acid etch to open dentinal tubules)
Don’t leave bleach in tooth long, risk of resorption
-
Prognosis
o
50% successful
o
29% acceptable
o
21% failure
o
7% resorption
Hydroxyl radicals diffuse through dentinal tubules breaking down periodontal tissue, causes
external cervical root resorption
Higher incidence of resorption when Superoxol used with heat
Superoxol = 30% HOOH
High diffusion through dentinal tubules
Place barrier directly on top of GP
Do NOT use heat
Do NOT use sodium perborate for superoxol
Endodontics
Course Review
Enoch Ng, DDS 2014
Outcomes and Complications
Treatment Factors affecting Healing
-
Iatrogenic factors
o
Blocked canals – debris packed into apex
Use rotary motion rather than push/pull motion
Keep canal wet, frequent irrigation – 1-2mL between files
Remove coronal restorations
Recapitulate with small file 0.5-1mm beyond WL
o
Ledges – from incorrect WL and curved canals
Get corrected WL ASAP
Always recapitulate
Use copious irrigation
Caution with gates glidden drills and increased file sizes
o
Separated files – torsional or fatigue failure
Prevention
Prepare adequate glide path
Never force and instrument, control rotary torque
Keep canal wet
Inspect files, don’t overuse files
Proper case selection
Removal
Location affects prognosis
Magnification, ultrasonics
Instruments threaded into dentin are harder to remove
Fatigue failure – friction is less, easier to remove
Legal responsibility to inform patient, documentation in chart
Non-removal
Bypass, leave in place and monitor
Consider how far along instrumentation was when separation occurred, new diagnosis
Prognosis if fractured instrument left in tooth is not significantly reduced
o
Missed Canals
o
Perforation
Mechanical/pathologic communication between root canal system and external tooth surface
Secondary perio inflammation involvement causing attachment loss
Bacterial infection from root canal or perio tissues prevents healing
Most common cause of root canal failure – best prognosis if perforation sealed immediately
Types – coronal, furcal, strip, apical, zip
Prevention
-
Know anatomy, carefully assess tooth angulation
and dimensions
-
Access slowly, take radiographs as needed
-
Caution with crowned, narrow, or calcified teeth
-
Explore cervical root morphology
Repair
-
MTA – biocompatible, good compressive strength,
less leakage than amalgam or IRM
-
Mix powder with sterile water, deliver to site
-
Condense with hand pluggers
-
Repeat until sealed, place moist cotton pellet and
temporary restoration, allow to set
Endodontics
Course Review
Enoch Ng, DDS 2014
Apical Healing
-
Clinically healed
o
No tenderness to percussion or palpation, no sinus tracts, no swelling
o
Normal mobility, properly restored
o
Radiographically healed
Normal PDL and lamina dura, absence of resorption and radiolucency
o
Histologically healed
No inflammation, restoration of PDL fibers, cementum and osseous repair, no resorption
-
Clinical Failure
o
Any symptoms
Evaluating outcomes
o
Peak healing time at 1 years
Radiographic healing at 1 year is good sign
o
Pre-operative apical periodontitis – may take up to 4 years to completely heal
o
Recall periods case specific, but all should be monitored 3-12 months postop
-
Clinically
o
Patient’s symptoms
o
Clinical exam
Percussion, palpation, mobility
Perio probings, sinus tract
o
Evaluating restoration
Proper cuspal coverage
-
Radiographically
o
Periapical and CBCT radiography
o
Pre and post-op lesion size
-
Histologically
o
25% of radiographically normal teeth are histologically inflamed
o
100% of teeth with radiographic apical radiolucency are histologically inflamed
Factors Affecting Healing
-
Multi-rooted teeth lower healing rates than single rooted teeth
-
Vital pulp > necrotic pulp
-
Larger lesions have lower healing
o
<5mm = 87%, >10mm = 73%
-
Presence of lesion gives 13% less healing
-
Preparation technique – adequate debridement and irrigation, flared preparation > stepback
-
Multivisit RCT with Ca(OH)
2
= 10% increased healing
-
Cavit temporary >3.5mm thick, good for 3 weeks only
-
Significant microleakage after >3days exposure to artificial saliva
-
Exposed GP root filling recontaminated by saliva in less than 30 days
-
For long term healing, quality of coronal seal > quality of obturation
-
History of radiation – 91% healing with RCT, no cases of osteoradionecrosis
-
Diabetes significantly decreases healing of RCT with a lesion
-
Smokers have lower healing rates
-
Age/gender do not affect outcomes
Endodontics
Course Review
Enoch Ng, DDS 2014
Non-Surgical Outcomes
-
Multifactorial, not all factors can be IDed
-
Should try to ID as many factors as possible pre-op, during op, post-op
o
Prognosis can change due to additional findings or iatrogenic damage
-
Keep patient informed
Overall healing from initial therapy
-
Complete healing = 83-86%
-
Incomplete healing = 86-91%
-
Functionally retained = 95%
-
97% NSRCT teeth retained after 8 years
-
85% extracted teeth did not have a crown
Overall healing from retreatment therapy
-
Complete healing = 80-82%
-
Incomplete healing = 86%
-
Functionally retained = 94%
-
98% healing if retreatment is due to defective
filling, much lower if due to persistent
radiolucency
Surgical Outcomes
-
74% healing rate over 4-8 years
-
91% functionally retained
-
Microsurgery = 91.5% healing at 5-7 years
-
Success rates for endo and implants are equal
o
Smoking only factor to significantly affect both
Non-Healing of RCT
-
Consider etiology
-
Address restorability
-
Options
o
No treatment
o
Retreatment
o
Apical surgery
o
Extraction (with or without replacement)
-
Symptomatic patients – POOR PAST
o
Perforation
o
Obturation
o
Overfill
o
Root Canal Missed
o
Periodontal Disease
o
Another tooth
o
Split tooth
o
Trauma (occlusion)
Microbiology
-
E. faecalis – 22-77% of post-treatment apical periodontitis cases
o
Resistant to intracanal medicaments
o
Tolerates pH up to 11.5, can survive prolonged starvation
o
May grow as monoinfection, can create biofilms, can undergo genetic mutation inside biofilms
-
Actinomyces – extraradicular colonies
o
Symptoms – multiple sinus tracts, extraoral sinus tracts, yellow “sulfur granules”
o
Can perpetuate apical inflammation even after ideal NSRCT, must be treated surgically
-
Fungi
-
Dentinal Tubule sequalae
o
Serves as a reservoir for microbes
Endodontics
Course Review
Enoch Ng, DDS 2014
Non-microbial Causes
-
Cysts – pathologic epithelium lined pocket filled with fluid and necrotic debris
bay cyst (pocket cyst) – cyst is connected to and opens into apex of canal
true cyst
residual cyst
o
Controversial whether will heal after NSRCT
o
Incidence – 5-55%, more current literature indicates 15-17% prevalence
o
Radiographs NOT diagnostic for cystic vs noncystic lesions
o
Suspect cyst if lesion > 200mm
2
-
Foreign Body Reaction
o
Extruded GP – delayed healing of apical tissues
o
Paper points
o
Amalgam
o
Sealer
o
Extruded Ca(OH)
2
-
Scars – very uncommon
o
Occasionally (2-6%) unresolved apical radiolucency may be a scar
o
Can only be determined histologically
Summary
-
Endo therapy = healing 82-94%
o
Dependent on pre-treatment and treatment factors
-
Persistant PA lesions caused by
o
Persisting intraradicular infection
o
Extraradicular infection, plaques, biofilms
o
Extruded RCT filling/other materials
o
Cysts
o
Scars
-
Treat microbes
-
Consider POORPAST for residual symptoms
-
Appreciate RCT complexity – know when to refer
-
Control your materials
-
Restore, follow up, keep patient informed
Endodontics
Course Review
Enoch Ng, DDS 2014
Dentoalveolar Trauma
-
Bye age 14, 25% of kids will have an injury involving permanent teeth
-
80% trauma for 7-15y/o kids is to incisors Mx and Mn
-
Pulps of young permanent dentition is large – good blood supply, better repair potential
o
May interrupt growth of immature teeth, resulting in thin weak teeth
-
Goal – to maintain pulpal vitality
Consequences
-
Structure of the tooth
-
Surrounding PDL
-
Vascular and nerve supply
-
Surrounding bone
-
Damage related to extent of displacement from original anatomic position
-
Management can be multidisciplinary
Med History
-
BP, pulse, temp, respiration
-
Medical conditions, allergies
o
Neurologic conditions – CNS eval, Glasgow coma scale
-
Drug interactions
-
Tetanus immunizations
Clinical Exam
-
Soft tissue, facial skeletal
-
Teeth and supporting structures
o
Mobility
o
Displacement
o
Perio damage
o
Pulpal injury
-
Radiographic exam
o
4 different radiographs, with attention to:
o
Dimension of root canal space
o
Degree of apical closure
o
Proximity of fracture to pulp
o
Proximity of fracture to alveolar crest
Dental Injuries
-
Enamel infraction
o
If necessary, etching and sealing with resin – prevent discoloration
o
No recall necessary unless associated with other trauma
-
Enamel fracture
o
Bond fractured piece back onto tooth, or restore with composite
o
3 radiographs (PA, occlusal, off angle) to rule out luxation injury or fracture
o
Recall 6-8 weeks, 1 year
-
Crown fracture without pulp involvement
o
Bond fractured piece, provisional with GI, or permanent with composite resin
o
3 radiographs (PA, occlusal, off angle) to rule out luxation injury or fracture
o
Radiographs of lip/cheek lacerations – search for tooth fragments or foreign material
o
Recall 6-8 weeks, 1 year
-
Crown fracture with pulp involvement
o
Immature tooth with open apex – preserve vital pulp to secure further root development
Pulp capping, partial pulpotomy, use Ca(OH)
2
or white MTA
o
Mature tooth with closed apex – NSRCT
Endodontics
Course Review
Enoch Ng, DDS 2014
-
Crown root fracture
o
Prognosis depends on apical extent of fracture into attachment apparatus
Pick any of these possible treatments
Fragment removal (pulpotomy)
Fragment removal and gingivectomy
Orthodontic extrusion
Surgical extrusion
Decoronation
Extraction
-
Root fracture
o
Reposition coronal segment of tooth
o
Flexible split for 4 weeks – for cervical fractures, split for 4 months
o
Soft diet for 1 week – good OH, soft bristle brush, chlorhexidine rinse
o
Recall 6-8 weeks, 4 months, 6 months, 1 year (annually for 5 years)
o
NSRCT of coronal segment if pulp necrosis occurs
-
Horizontal Root Fracture
o
More cervical = bad
o
Pulpal necrosis 25% of the time
o
Rigid split for 12 weeks, monitor pulp vitality
o
Hard tissue induction at fracture site, then RCT of coronal segment
Techniques
-
VPT (vital pulp therapy)
Pulp capping
Partial pulpotomy
Cervical pulpotomy
o
Goal – preserve pulp tissue
-
Cvek technique
o
Remove inflamed tissue 2mm below exposure site with water cooled small diamond
Place Ca(OH)
2
liner, restore with acid-etch technique
o
<24hrs – pulp capping – 80% success
o
>24hrs – partial pulpotomy – 94-96% success
o
>72hrs – cervical pulptomy – 75% success
Healing of Root Fractures
-
Calcified tissue
-
Connective tissue
-
Bone and CT
-
Non-union with GT
Dental Injuries
-
Fracture of Alveolar Process
o
Reposition and flexible splint for 4 weeks
o
Monitor pulp vitality
o
Recall 4 weeks, 6-8 weeks, 6 months, 1 year (annually for 5 years)
Remove splint at 4 weeks, take clinical and radiographic exam to check healing
Endodontics
Course Review
Enoch Ng, DDS 2014
-
Luxation
o
Concussion – injury to tooth without increased mobility or displacement, pain on percussion
No treatment, soft food for 1 week, good OH
Recall 4 weeks, 6-8 weeks, 1 year
o
Subluxation – no displacement, but increased mobility and bleeding of gingival sulcus
No treatment to flexible splint for 2 weeks, adjust occlusion
Soft food for 1 week, good OH
Recall 4 weeks, 6-8 weeks, 1 year
o
Lateral luxation – displacement non-axially with labial or lingual alveolar bone fracture
Reposition tooth AND displaced bone with finger pressure and forceps
Splint for 4 weeks (resin or wire composite)
Recall 4 weeks, 6-8 weeks, 6 months, 1 year (annually for 5 years)
Remove splint at 4 weeks, take clinical and radiographic exam to check healing
o
Extrusion – axial displacement with intact alveolar bone socket
Reposition tooth, flexible split 2 weeks (resin or wire composite)
Soft food 1 week, good OH, splint removal after 2 weeks
Recall 4 weeks, 6-8 weeks, 1 year (annually for 5 years)
o
Intrusion – displacement of tooth into alveolar bone with fracture of alveolar bone
Primary or immature permanent tooth – spontaneous eruption
Orthodontic or surgical repositioning followed by RCT
o
Luxation Outcomes
Concussion – 2% PN
Subluxation – 12-20% PN
Lateral/extrusive – 50-75% PN
Intrusive – 96-100% PN
Pulp calcification – 20-25%
Root resorption – 5-15%
-
Avulsion – complete displacement of tooth out of socket, socket is empty or filled with coagulant
Complications – damage and drying of PDL, pulpal necrosis
Consider – time out of mouth, open apex, storage medium (HBSS, milk, saline, saliva, water)
o
Drying time of PDL > 2hrs – all cells are dead
Medical history, tetanus booster
Antibiotic therapy
o
<12y/o – Pen V 25-50mg/kg body weight QID for 7 days
o
>12y/o – 100mg doxycycline BID for 7 days
or
Pen V 500mg QID for 7 days
Root end development (open apex)
Root surface conditioning
o
Citric acid soaking – removes necrotic tissue
o
Doxycycline soaking – kills bacteria, promotes revascularization
o
2-4% NaF soaking – makes root resistant to resorption
o
Reposition tooth
o
Physiologic split for 2 weeks
0.015-0.030 ortho wire, resin bonded, 20-30# nylon fishing line
o
Remove pulp within 7-10 days, Ca(OH)
2
medicate canal
o
Obturate when no signs of resorption
o
Recall to monitor signs of resorption (surface, inflammatory, replacement)
Endodontics
Course Review
Enoch Ng, DDS 2014
Retreatment
Retreatment Outcomes
Nonsurgical – 73%
Surgical – 57%
2
nd
nonsurgical – 47%
Replantation – 41%
Overall – 65%
Nonsurgical retreatment – 75%
Surgical retreatment – 59%
Surgery after NSRCT retreatment – 80%
Phases I and II
-
81% healed
-
93% functional
Phases III and IV
-
82% healed
-
86% improved
-
94% functional
Etiology of Non-Healing
o
89% of NSRCT teeth by endo specialists retained after 5 years
-
Inadequate seal
o
Coronally – leaky crown/filling
o
Apically – poor obturation/condensation, short fill, overextended fill
o
Perforation – untreated/leaky mechanical perforation in chamber floor/canal
o
Resorption
-
Untreated/contaminated canal space
o
Non-negotiable canal – dilacerations, ledge, calcification
o
Inadequate instrumentation
o
Lateral canal
o
Missed canal
-
Separate instruments/fragments
o
May block cleaning and sealing of canal system
-
Vertical root fracture
-
Trauma – resorption, fracture, avulsion
Indications of Non-Healing
-
Sporadic, vague symptoms
-
Widened PDL space
-
Static radiolucency/slight repair
-
Voids in obturation in apical 1/3
-
Overfill beyond anatomic apex
Causes of Non-Healing
-
Periodontal involvement
-
Host factors
o
Non-odontogenic pathology
o
Systemic conditions (diabetes)
-
Misdiagnosis – another tooth is the etiology
Surgical Considerations
-
Inability to reach/seal apex through canal
-
Unable to remove old canal filling
-
Unable to remove post or other canal obstructions
-
Severe apical perforation/zip
Endodontics
Course Review
Enoch Ng, DDS 2014
Non-Surgical Retreatment
-
Gain access to canal system and reach apical foramen via removal/bypass of obturation materials from canal
-
Patient usually has high outcome expectations
-
Requires greater clinical skill than original NSRCT treatment
-
Canal Obstructions – posts, separated instruments
o
Reduce retention – loosen with ultrasonics, twist/pull out post, relieve dentin in coronal portion of canal
o
Directly cut out post/instrument
o
Hazards
Perforation while attempting to ditch around post
Root fracture upon removal
Excessive temperature generation/root perforation while trying to cut through post
o
Separated Instruments/carrier systems removal
Technically difficult, requires special equipment
Access – cannot remove what you cannot reach
Visualization – usually can remove what you can see, optimal magnification and illumination
Operating microscope or high powered loupes with light
Microsurgical forceps
Stieglitz pliers
Endo extractor kit
-
Obturation materials – pastes, semi-solid materials, solid materials, carrier systems
o
Original obturation materials
54% GP
21% pastes/cements
19% silver points
2.4% combination
2.2% broken instruments
0.5% none (periradicular surgery without fill)
o
GP removal
Quality of condensation
Shape of root canal
Length of obturation material – short fill, overextension, etc
System B
Gates Gliddens, ProFiles, GPX
Removes GP quickly
Provides reservoir for solvent
Heat and hedstrom removal technique
o
Solvents
Chloroform
Methylchloroform, Eucalyptol, Halothane, Xylene, Rectified white turpentine
-
Existing restorations – crowns, abutments (FPD, RPD), core materials (amalgam, composite, GI)
Summary
-
Technically more difficult that original NSRCT
-
Special instruments, materials, techniques required
-
Healing outcome less than original treatment in older literature
Endodontics
Course Review
Enoch Ng, DDS 2014
Endodontic Surgery
Root End Resection
-
Most common cause for NSRCT failure, need for root end resection = incomplete cleansing of root canal system
-
Amount of root end resection
1mm 2mm 3mm
Apical ramifications 52%
78%
98%
Lateral canals
40%
86%
93%
-
Root End Surgery
o
Flap resection
o
Ostectomy
o
Root end resection – apicoectomy
o
Root end preparation – retro-prep
Class I prep – 3mm in depth
Centered in canal in along axis of tooth
Include all canals and isthmus area between canals
o
Root end filling – retro-filling
Materials – superEBA, IRM, amalgam, GP, ZOE, cavit, GIC, resin bonding agents, MTA
Best choices – MTA, IRM, superEBA
Hazardous material = Portland cement (75% by weight)
o
Root end finishing
o
Closure and suturing
Extraction replantation
o
Good candidates – straight root (some furcation)
o
Good/bad candidate – fused roots
o
Bad candidate – wide/dilacerated roots
-
Cut off 2-3mm off bottom of roots before reimplantation
Other Procedures
-
Root resection/horizontal root amputation – 4.5month postop
-
Repair of resorptive defect
-
Repair of procedural complications
-
Autotransplantation
-
Decompression of large apical lesions – syringe used to withdraw fluid
Advances in endo surgery
-
Dental operating microscope
-
Microsurgical instruments
-
Soft tissue management principles
-
Ultrasonic root end preparations
-
Improved root end filling materials
-
Regenerative techniques
Endodontics
Course Review
Enoch Ng, DDS 2014
Treatment Planning Considerations
-
Medical history
-
Dental history
-
Success of NSRCT or retreatment
-
Patient motivation/apprehension
-
Esthetics
o
Scarring
o
Exposure of crown margins
-
Clinical considerations
o
Dentition
Caries
Restorative deficiencies
Cracks
Sensitivity testing
o
Periodontal status
Probings/pocket depths
Recession
Width of attached gingiva
Health of gingiva – need good oral hygiene
Bone loss/furcations
Endo-perio lesions
o
Soft tissue
Muscle attachments and frenums
Sinus tracts
Pre-existing scar tissue
o
Anatomic structures
Height/depth of buccal vestibule
Height/depth of palate
Size of oral cavity, patients ability to open
Chin prominence, mandibular buccal plate
o
Radiographic considerations
Short roots, long roots
Presence/size of lesion
Mx sinus, Mn canal, mental foramen, buccal oblique ridge
Exostosis
o
Prosthodontic considerations
Presence of crowns/bridges
Type of post used
o
Restorative plan
Prognosis
-
Different studies give different results
IEJ 2000
IEG 2001
JOE 2009
JOE 2010
91.2% healed
88% healed
8% healing
4% non-healed
91.6% healed at 1 year post-op
74% healed
94% functional
Endodontics
Course Review
Enoch Ng, DDS 2014
Endo-Perio
Pulpal/Perio Communication
-
Dentinal tubules
-
Accessory canals
o
27.4% of teeth have accessory canals
Apical area – 17%
Middle third – 8.8%
Coronal third – 1.6%
o
28.4% molars (Mx and Mn) have accessory furcation canals
-
Apical foramina
-
Palatal groove
Pulpal Perio Disease
-
Bacterial infection of the pulp system induces significant inflammatory and immune response in apical tissues
-
Untreated endodontic disease may support an increase in:
o
Pocket depth
o
Bone loss
-
Perio treatment of teeth with pulpal necrosis and ARL resulted in delayed or impaired perio healing
-
If blood supply through apical foramen is intact, perio disease rarely jeopardizes vital function of pulp
-
Pulpal inflammation can come from exposure of lateral canals
-
Pulpal necrosis results from main apical foramen invaded by bacteria
-
Potential exists for S&RP to open dentinal tubules – indirectly induce localized pulpitis
-
Microorganisms found in infected root canals of caries-free teeth with advanced perio usually resemble those
found in adjacent perio pockets
Endodontic Lesions
-
Endo lesions associated with inflamed/necrotic pulp with distinct etiology for pathosis
o
Caries, restorations, cracks, trauma, attrition, abrasion, erosion
-
Perio lesions usually associated with local factors that induce inflammation
o
Bacteria, plaque, calculus
-
Periodontal origin – generalized, broad lesions
-
Pulpal origin – narrow coronally, isolated
Glickman’s Classification
-
Grade I – engaged flutes – pocket formation into the flute of the furca, but interradicular bone intact
-
Grade II – engaged roof – loss of interradicular bone, pocket formation of varying depths into furca but not
completely through (dead end, cul de sac)
-
Grade III – probe thru – complete loss of interradicular bone with a pocket probable to opposite side of tooth
-
Grade IV – see thru – grade III with advanced gingival tissue recession that has made furca clearly visible during
clinical Exam
Endodontics
Course Review
Enoch Ng, DDS 2014
Lesion Classification
-
Primary endo
o
Inflamed/necrotic pulp
o
Possible isolated perio defect
o
Osseous destruction localized to involved tooth
o
Healing via regeneration of perio and osseous structures
o
Endo treatment only
-
Primary perio
o
Generalized bone loss
o
Local factors present
o
Healing usually via reattachment
o
Vital pulp
o
Perio treatment only
-
Primary endo with secondary perio
o
Endo disease caused a perio communication
o
Endo treat first, evaluate after 2 months, perio treat if needed
-
Primary perio with secondary endo
o
Perio disease, then necrotic pulp
o
Osseous destruction exposes dentinal tubules, accessory canals, apical foramen
o
Endo treat first, then perio treat 2 months later
-
Concomitant endo-perio
o
Endo and perio disease exist separately
o
Endo treat first, then perio treat 2 months later
-
True combined
o
Endo and perio lesions eventually joined at a position on the root
o
Endo treat first, then perio treat 2 months later
-
Summary
o
Endo treat completed before perio start
o
Perio treatment 2 months after endo, only if needed
o
Perio condition generally dictates overall prognosis
Longitudinal Tooth Fractures
-
Craze Lines
o
Confined to enamel – no discomfort
o
Natural or due to trauma – no treatment necessary, maybe for esthetics
-
Fractured Cusp
o
Lack of cusp support from weakened marginal ridge
o
Brief sharp pain on biting, variable cold sensitivity
o
Transillumination and bite tests to ID cusp
o
Pulp test, remove fractured segment, restore tooth
o
79% molar fractures
Mx – 66% buccal, 34% lingual
Mn – 75% lingual, 25% buccal
o
21% premolar fractures
Endodontics
Course Review
Enoch Ng, DDS 2014
-
Cracked Tooth
o
Incomplete fracture
o
May or may not involve pulp
o
Extends from occlusal to apical
o
Mesiodistal direction
o
Excursive interference precursor for fracture
o
Restored teeth 29x more likely to fracture than unrestored teeth
o
Dental History
Repeated occlusal adjustments with minimal/transient decrease in symptoms
Vague/elusive symptoms
Extensive restorative history
Parafunctional habits
History of cracked teeth, history of trauma
o
Subjective Exam
Episodic discomfort on biting
Patient remembering precipitating incident
Patient may not localize or ID tooth accurately
o
Clinical Exam
Visual – restoration integrity, marginal discoloration
Tactile exam with explorer
Perio probings – isolated defect
Percussion – might have sensitivity
Bite test – sensitive on bite or release
transillumination
o
Radiographics
Variable detection
Fractures not usually visible
o
Restoration removal
Allows access
Aids in placement of stain to determine extent of crack
Methylene blue = caries indicator helps visualize location, direction, extent of crack
Necessary to determine mobility of segments
o
Treatment
Cuspal coverage restorations may impede propagation of racks
Orthodontic bands
Occlusion reduction
Reduce height of non-functional cusps
Eliminate occlusal contacts on non-functional cusp
Re-contour outer incline of non-functional cusp
NSRCT when indicated by diagnosis – sensitivity testing shows pulpal damage is irreversible
Tooth prognosis decreases as crack propagation continues
21% of teeth with reversible pulpitis from cracks will require NSRCT in 6 months
Cuspal coverage = almost 0% failure
No cuspal coverage, composite restorations instead = 6% annual failure
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