Periradicular Surgery Flashcards
What are the steps of management of failure?
- Monitor
- Attempt orthograde
retreatment - Periradicular surgery
- Extract
What are most periapical pathologies?
granuloma
What is periradicular surgery?
Surgical shortening of the root apex +/- retrograde sealing
What are the indications for surgery?
- Failure of previous endodontic treatment
If retreatment is not possible or will not correct the problem - Anatomical deviations
Prevent complete cleaning and obturation
Tortuous, curved roots, pulp stones, calcifications - Procedural errors
Ledges, blocks, perforations, breakages,
underfill, overfill - Exploratory surgery
Identification of root fractures
What are the contraindications of surgery?
- Anatomical factors
Proximity to neurovascular bundles - Inadequate periodontal support
- Non-restorable tooth
- Medical factors
Leukaemia, neutropenia, recent heart or cancer surgery
Postpone if recent MI or radiation treatment - Skill and ability of surgeon Referral of complex cases
What is microsurgery?
Surgery using operating microscopes and miniaturized precision instruments to perform intricate procedures on very small structures
What is the triad of endodontic microsurgery?
magnification
instruments
illumination
What do soft tissue elevators do?
– Designed to allow elevation of soft tissue from cortical bone with minimal trauma
– Thin sharp edges allows soft tissue to be elevated cleanly and completely
What are ultrasonic units made of and what are the vibrations?
– Vibrations 30 – 40 kHz
– Excitation of quartz or ceramic piezoelectric crystals
When should haemostatic control be achieved?
*Adequate haemostasis is absolutely essential
* Bone crypt must be examined at high magnification
* Haemostatic control
– Pre-operative
– Intra-operative
– Post-operative
What is included in the pre-operative phase?
LA and haemostasis
What LA is used?
2% lidocaine with vasoconstrictor 1:50 000 epinephrine
What are topical haemostatic agents used intra-operatively?
– Epinephrine pellets
* Most effective and economic
– Ferric sulphate
* Agglutination of blood proteins – forms a plug
* Cytotoxic, tissue necrosis
* Adverse effects on osseous healing
– Calcium sulphate
* Mechanically blocks open vessels
* Aids in bone regeneration
How can haemostasis be maintained after flap has been sutured?
– Finger pressure on a wet sterile gauze
What is a sulcular full thickness flap design?
– Horizontal and vertical incisions
– Vertical incisions follow line of tissue fibres and blood vessels
What is a mucogingival flap design?
– Crowned anterior teeth
– Scalloped incision in middle of attached gingiva at 45°
– Vertical relieving incisions
How should incisions be done?
- Interproximal papillae cut with mini blade following contour of tooth neck
- Vertical incisions must start at line angle and follow fibre line straight up
How is flap elevation done?
- Place elevator beneath gingivae at line angle
- Reflect apically with a slow, firm motion to prevent tearing
- Reflect periosteum completely to prevent bleeding
How is flap retraction done and why is it important?
- Stable and non-traumatic retraction
- Serrated tips give better anchorage
- Poor retraction is key factor in post-op swelling and transient paraesthesia
What is osteotomy?
Removal of cortical plate to expose root end
What should you look for to plan osteotomy?
– Assess length and curvature of roots using preoperative radiograph
– Look at proximity to adjacent teeth, mental foramen, mandibular nerve and sinus space
Why is smaller osteotomy better?
- A conservative osteotomy allows faster healing
- Larger osteotomy increases chances of fibrous healing
- Microscope use allows osteotomy dimensions to be minimised
– Root is a darker yellow colour
– Methylene blue demonstrates periodontal ligament
What are the clinical possibilities?
- Intact cortical plate with no radiographic lesion
- Intact cortical plate with a periapical lesion
- Fenestration through cortical plate leading to apex
Tips for osteotomy?
- Keep it as small as practicable
- Curettes are used to remove granulation tissue
- Lingual/palatal aspect may only be cleaned after root resection
What is root end resection?
3mm is resected perpendicular to long axis of tooth – Removes majority of lateral canals and ramifications
How is ultrasonic root end prep carried out?
- Carried out under low magnification
- Ultrasonic tip is positioned at apex
- Use copious coolant to a depth of 3mm
- Inspect with a micro-mirror at high magnification
– Remnants of gutta-percha
– Recondense gutta-percha
How can you clean and dry apical prep?
- Absorbent paper points
- Stropko device
– Pressure reduced to 10 psi to avoid air embolism
What should you inspect in the resected root surface?
- Isthmi
- C shaped canals
- Canal fins
- Apical micro-fractures
- Poorly adapted gutta-percha
What is the frequency of an isthmus in mesial roots of mandibular first molars?
70%
What is the clinical significance of the isthmus?
- Untreated isthmi are one of the main causes of surgical failure
- Identification is extremely important using microscope and micromirrors
- Ultrasonic preparation with KiS-1tip
What should root end filling do?
This should seal the apex so that bacteria or their products cannot enter or leave the canal
What are properties of root end filling materials?
– Well tolerated by apical tissues
– Bactericidal or bacteriostatic
– Adhere to tooth
– Dimensionally stable
– Easy to handle
– Do not stain
– Noncorrosive
– Do not dissolve
– Promote cementogenesis
– Radiopaque
Why should you not use amalgam for root end filling?
Poor clinical performance
– Sets slowly
– Biocompatibility
– Leakage
– Corrosion and staining
What makes up MTA?
Powder consisting of fine hydrophilic particles
– Tricalcium silicate
– Tricalcium aluminate
– Tricalcium oxide
– Silicate oxide
– Bismuth oxide
What are the advantages of MTA?
- Long setting time
- Superior sealing ability
- Moisture tolerant
- Radiopaque
- Excellent biocompatibility
- Regeneration of cementum
How should MTA be used?
- Protect bone crypt
- Mix powder with sterile water to putty
consistency - Carry to root end with a MTA gun or Dovgan carrier
- Use micropluggers/burnishers to lightly condense material
- Wipe off excess with a small moist cotton pellet
What are regenerative procedures used in periodontal surgery?
guided tissue regeneration
How should you reposition and suture the flap?
- Ensure correct position
- Apply a damp gauze with fingerpressure
- Place first suture at free end of flap
- Use interrupted sutures
– Ideally monofilament (e.g. Polypropylene or PTFE) - Remove sutures after 72 hours
When is bruising worse?
- Worse 3-4 days after procedure
- Often occurs distant from surgical site
What is paraesthesia and how can it occur?
- Abnormal sensation or numbness caused by impingement, handling, laceration or severance of a nerve
- Often transient caused by swelling as a result of inflammation
- Normal sensation returns in 4 weeks
What are other complications of surgery?
- Serious infection
– Rarely occurs
– Treated with antibiotics - Lacerations
– Prevent by application of Vaseline to lips
– Avoid careless elevation of flap - Maxillary sinus perforation
– Suturing of flap sufficient
What are the classifications of healing?
– Healed
– Incomplete healing (Scar) – Uncertain healing
– Failed
When should follow up occur after endodontic surgery?
Follow-up one year initially and then up to four years
What are prognostic factors that may affect result?
- Age
- Tooth Position
- Root-end filling material
- Presence of co-existing periodontal disease
- Apical seal
- Coronal seal
- Crypt size
What is always preferable to root end surgery?
retreatment
