Apical Surgery

Question 1

What is apical surgery also know as?

Answer 1

Endodontic surgery / root end surgery / apicoectomy

Question 2

How would we deal with a perforation/resorption repair?

Answer 2

Open a flap and close with GIC

Question 3

What is involved in a hemisection?

Answer 3

Cutting a tooth in half (PREMOLARISATION- cutting a molar to split it, making it look like 2 premolars)

Question 4

What does trephination involve?

Answer 4

A hole in bone is made to release accumulated tissue exudate, increasing healing

Question 5

What does decompression involve?

Answer 5

Placing a surgical drain to rid cystic fluid from a large lesion to shrink it

This makes a second surgery to remove granulation tissue much easier

Question 6

What does intentional reimplantation involve?

Answer 6

Extracting a tooth as atraumatically as possible, root fill the tooth and reimplant it.

Question 7

What is the difference between orthograde and retrograde?

Answer 7

Orthograde: Access the tooth through the crown
Retrograde: Access the tooth from root tip

Question 8

How do we assess failed endodontics?

Answer 8

1. Clinical and radiographic findings
2. Patient factors: medical, cooperation, motivation, consent
3. Oral factors: Maintenance, function, aesthetics, adjacent teeth
4. Tooth factors: Coronal seal, quality of RCT, access to canal/root end/structures

Question 9

How can we gauge whether an apex of a tooth is close to any nerves?

Answer 9

Take a CBCT scan

Question 10

What affects success of Endodontic surgery?

Answer 10

Depends on tooth and operator experience

Lower success rates if pre treated edodontically

Coronal seal quality is VERY important

• None surgical treatment is better than surgical treatment - it is a final approach

Question 11

What is apical surgery? IN SIMPLE TERMS

Answer 11

In simple terms:
1. Cleaning out tissue at the top of the tooth
2. Chop off tip from root
3. Put in filling material
4. Stitch up and wait for healing

Question 12

Stages of apical surgery in detail?

Answer 12

1. Identify region to be managed
2. Determine flap design
3. Once flap raised, identify lesion and apex. Then curettage of apical tissue (be sure to send for biopsy as occasionally apical infection can be cancer)
4. Root end resection - tip of root with abnormal anatomy removed with high speed surgical handpiece
5. Root end filling materials- instrumentation
6. Would closure
7. Post-op care and review

Question 13

What do we do if there is bone impeding access to the apical part of tooth?

Answer 13

We do an osteoectomy to remove the bone.
Often there will be a fenestration in the bone (resorbed cortical plate) to guide where to widen the it.

Must use plenty of irrigation to reduce heat generation, preventing bone necrosis

Question 14

What factors must we compromise between in flap design?

Answer 14

1. Access
2. Vision
3. Recession (hence why we usually extend flap to roughly the teeth either side)

Question 15

What factors affect flap design?

Answer 15

1. Size and site of lesion - must not incise over lesion
2. Presence of crowns/veneers - risk of recession
3. Depth of sulcus/vestibule
4. Presence of frena/bony prominences/thin tissue biotypes/muscle attachments (cutting through it can cause muscle weakness)

Question 16

Types of flap designs?

Answer 16

1. Full muco-periosteal flaps - from gingival margin to sulcus
   -triangular: 2 sided flap - 1 vertical relieving incision (how we surgically extract teeth)
   -rectangular: two vertical relieving incisions
   -trapezoid: two angled vertical relieving incisions
2. Limited mucoperiosteal flaps
   -submarginal AKA Ochsenbein–Luebke flap: Cut at junction between keratinised and non-keratinised tissue to minimise recession.
   -papilla base: two vertical realising incisions connected by horizontal incision at papilla base (do over submarginal if lesion is larger)

SEE DIAGRAMS ON NOTES

Question 17

Why would we use a full mucoperiosteal flap?

Answer 17

1. Easy to reflect and reposition
2. Easy access to lesion
3. Good healing
   BUT may lead to post-op recession so ideally leave 3mm of gingivae from margin.

Question 18

Why would we use a limited mucoperiosteal flap?

Answer 18

1. Avoids recession
2. Easy reference points for reattachment
3. Limited scarring

Question 19

Why might a flap result in scarring?

Answer 19

If the suture to close it isn’t well done

Question 20

What part of a flap should you suture first?

Answer 20

Base of contour first (see diagrams - slide 30)

Question 21

Which needles should we use to suture flaps?

Answer 21

Small needles because gingival is tighter so reduces risk of tearing tissue

Question 22

Where are lesions usually situated in lateral incisors?

Answer 22

Distally

Question 23

How do we describe a lesion that once excised, leaves no palatal cortical tissue left?

Answer 23

Through and through

Healing processes are more difficult to achieve in these lesions

Question 24

How do we do a root end resection

Answer 24

1. Usually with a bur
2. Tip of root removed - studies show apical 3mm have most accessory anatomy/abnormal anatomy and area that is most difficult to clean
3. Done at a 90 degree angle - historically did 45 degrees to facilitate vision of root end for prep and filling but now we have better microsurgical techniques that allow for a biologically better option (the 90 degree option)
4. Small class 1 cavity made into tip of tooth (root dentine) to remove around 3mm of GP to be filled

Question 25

Why is tip of root chopped off at 90 degrees better than 45 degrees?

Answer 25

Much less exposure of dentinal tubules if resected at 90 but this can be hard especially in lower incisor region (imagine the positioning of the bur in that area!)

Question 26

What are micro mirrors used for?

Answer 26

Allows vision of tooth tip - we can cut root at right angles

Question 27

What are Peizon tips used for?

Answer 27

Used to prepare class 1 cavity

Question 28

How do we do a root end preparation?

Answer 28

1. Retropreparation using ultrasonic tip to remove 2-3mm of GP 2. Pack root filling (MTA or other bio ceramic cement) into retro prep cavity

Question 29

What material did they use historically as a root filling?

Answer 29

Amalgam but can lead to amalgam tattoos

Question 30

How can we improve vision field to allow easy MTA packing?

Answer 30

Pack a gauze saturated with adrenaline to reduce bleeding

Question 31

How can we spot through and through resorption on a radiograph?

Answer 31

Area is really black, no bone (otherwise it is just radiolucent)- see slide 54

Question 32

What are the success rates of root filling materials?

Answer 32

Amalgam: 75% Reinforced eugenol cements (IRM/ Super EBA) : 90-95% MTA: 95-97%

Question 33

What are the properties of MTA?

Answer 33

1. Slowly sets in moisture 2. High pH - antimicrobial 3. Good sealing ability and biocompatible 4. Osteoconductive: bone can grow directly on MTA 5. Osteoinductive: induces bone growth onto its surface Disadvantages: Hard to use, its like packing wet sand but they have put in a plasticiser to combat this Very expensive

Question 34

What colour did MTA used to be and what colour is it now?

Answer 34

Used to be grey like amalgam, now it is white

Question 35

What are the indications for apical surgery?

Answer 35

1. Remove source of infection of Endodontics origin where this isn't possible non-surgically 2. Repair damage (pathological or iatrogenic) that can't be accessed non-surgically 3. Extruded material with no symptoms, can remove 4. Need a sample of apical tissue for biopsy 5. Assess teeth where a definitive diagnosis cannot be made without direct visual access

Question 36

What are the indications for re-treatment (non-surgical)?

Answer 36

1. Persisting symptoms/signs 2. Inadequate cleaning, shaping or obturation 3. Missing canals 4. Poor coronal seal/replacement of coronal restoration

Question 37

What are the contraindications of apical surgery?

Answer 37

- In most cases non-surgical pre-treatment have better prognosis 1. Poor operator experience 2. Patient factors (Medical-complex/Psychological- nerves as it can get quite stressful) 3. Access to surgical site ( Lower incisors: hard to reach apical area/ Frenum high: hard to get it flat/ canine: long tooth/upper 6: palatally risk of sinus/limited mouth opening: hard to access posterior teeth) 4. Local anatomical factors- sinus, nerves and vessels 5. Poor restorative or periodontal prognosis

Question 38

Advantages of orthograde approach?

Answer 38

Allows us to kill microbes in the root canal system with irrigant Allows clear access to all of the root canal system We can use magnification to view extra canals Avoids surgical procedure Randomised controlled trials shows it has the highest success rates

Question 39

Disadvantages of orthograde approach?

Answer 39

Longer treatment times/ may require multiple visits There is a risk of root fracture (especially if we have to remove a post) Highly dependent on the skill of the operator More expensive

Question 40

How would we close the wound after the procedure

Answer 40

We place the flap back to either: 1. Where we removed the flap from 2. Slightly coronal to where we removed the flap (recession takes it back to original place) We can use sling or oblique sutures

Question 41

What pre-operative factors affect outcome?

Answer 41

1. AGE 2. Sex - males heal better 3. Health- eg diabetics have worse healing 4. Tooth location- anterior better bc easy access 5. Clinical signs/symptoms: symptomatic/sinuses reduce change of success 6.Size of lesions 7. Bone loss- limited support 8. Coronal seal- no coronal seal reduces success 9. Resurgery- less success bc resecting more of the tooth means less root, less support, more perio issues

Question 42

Intra-operative factors affecting outcome?

Answer 42

1. Degree of bevel/level of resection - 90 degrees is best 2. Retrograde prep method- ultrasonics better than straight bur 3. Retrograde root filling/material - MTA> amalgam 4. Haemostatic agent - better vision 5. Magnification 6. Bone grafting- if not much bone there however we tend to avoid doing this as we want to regenerate natural bony infill

Question 43

Why would we do apical surgery even if we are planning on getting rid of the tooth eventually?

Answer 43

Pre-implant theory: By doing apical surgery, we encourage the generation of natural bone. This means that even if we extend the tooth's life by only a few years, we increase the bone levels we would've otherwise had, making implants a more viable option for patients later down the line.

Question 44

Why does classic literature suggest apical surgery success rates are lower?

Answer 44

They do not reflect contemporary methods (90 degrees instead of the old 45 degrees etc) and we have better idea of case selection/ knowledge of why endo txt fails.

Question 45

What issues could you encounter with doing surgery on anterior maxillary teeth?

Answer 45

o Apex of lateral tend to lie deep if the teeth are proclined o Canines are long teeth, so the apex is at the side of your nose

Question 46

What issues could you encounter with doing surgery on anterior mandibular teeth?

Answer 46

o The apex tends to lie deep & difficult to get to o Have to be mindful of mentalis

Question 47

What issues could you encounter with doing surgery on posterior mandibular teeth?

Answer 47

o ID nerve can tend to cause an issue o Have to be mindful of buccinator

Question 48

What issues could you encounter with doing surgery on posterior maxillary teeth?

Answer 48

o The sinus can get in the way o Palatal roots are difficult to access o The zygomatic buttress can tend to get in the way

Question 49

Signs of a successful surgery?

Answer 49

Absence of symptoms No sinus tract No loss of function Soft tissue healing Bony infill If these are reached within 4 years = success