Furcation and tissue regeneration

• What is furcation involvement?

  extension of periodontitis with connective tissue loss in a vertical and horizontal direction between the roots of multi-rooted teeth
• How are furcation's detected?

  • Clinically
  • Radiographically

  
• How do you detect furcation involvement?

  • measure each individually for every furcation entrance
  • pocket measuring probe or (Nabers) furcation probe
• What probe is used for curvatures?

  Nabers

  
• Who classified Furcation's?

  Hamp et al (1975)
• What is Grade 1?

  loss of periodontal support < 1/3 of tooth width
• What is Grade 2?

  loss of periodontal support > 1/3 of tooth width but not through and through
• What is Grade 3?

  Through and through destruction
• What are anatomical considerations for furcation involvement?

  • tooth type (eg canine, molar)
  • root number/morphology
  • root trunk morphology
• How many furcation entrances do upper molars have?

  3
• Can there be four or five rooted maxillary molars?

  YES!

  
• What are the furcation entrances for maxillary molars?

  
• What are some anatomical considerations when looking at furcation's?

  • Multi rooted teeth usually situated posteriorly (difficult access)

  • Posterior teeth have broad contact points (impede access)

  • Mesial and distal restorations are adjacent to the furcation entrances (margin position and finish are critical )

  
• What are some altered anatomical features to consider?

  - Pearls/spurs

  - Grooves
• What is the canine fossa?

  Can complicate RSD

  
• What is the anatomy of the upper molar?

  • Buccal furcation is accessed from the buccal aspect

  • Mesio buccal root is broad. Therefore the mesial furcation entrance tends to be accessed from the mesio palatal aspect.

  • The palatal root tends to be situated slightly distally and due to its greater diameter the distal furcation tends to be accessed from the distobuccal aspect

  
• What are examples of 3 rooted premolars?

  
• What is the anatomy of the maxillary premolars?

  
• How many roots do the lower molars have?

  
• Can Mandibular molars have 3 roots?

  Yes!

  
• What is the anatomy of the Mandibular molars?

  
• Canines and incisors have more than one....

  ...root and therefore have a furcation entrance!

  
• How large are furcation entrances?

  • 60% of furcation entrances are less than 0.75mm

  
  

  • Blade width of Gracey curette is 0.75mm

  
• What can be found inside a furcation?

  Concavities

  Maxillary molars

  • MB root 94% (0.3mm deep)

  • DB root 31%

  • Palatal root 17%Mandibular molars

  • Mesial root 100% (0.7mm deep)

  • Distal root 99% (0.5mm deep)
• What is the average depth of the concavity in a premolar?

  
• What are the two main objectives of treatment of furcation's?

  1. Elimination of microbial plaque from the affected root complex.

  
  

  2. Facilitation of adequate self-performed plaque control
• What is the non surgical treatment of furcation lesions?

  - OHI with focused attention to interdental and subgingival plaque removal

  
  

  - Supra/sub gingival scaling

  
  

  - Root surface debridement

  
• How can furcation's be made cleansable?

  • Surgically remove or reposition soft tissue to expose furcation

  
  

  • Re-contour furcation (Furcoplasty)[class I/II]

  
• How can furcation's be opened?

  Open the furcation:

  - Tunnelling

  (Class II/III)

  - Root amputation

  (Class II/III)

  -Hemisection

  (Class II/III)

  - Premolarise

  (Class II/III)
• Can a furcation be closed?

  Yes!! Guided Tissue Regeneration [class I/II furcation defects]

  • Buccal/lingual lower molars

  • Buccal upper molars

  
• What happens when furcation involved teeth are extracted?

  • Extensive attachment loss

  • Inability to provide anatomy that allows optimal OH measures

  • Preservation of the tooth would otherwise represent a risk factor for the long-term prognosis of the overall treatment
• What is guided tissue regeneration?

  Connective Tissue Attachment

  • Control of movement of cell populations

  • Osseo-conduction: matrix/scaffold onto which bone may form

  • Osseo-induction: progenitor cells of the surrounding recipient bed to form new bone
• What cells are involved in the healing process in tissue regeneration?

  • epithelial cells - rapid proliferation
  • connective tissue fibroblasts - rapid proliferation
  • osteoblasts - slow proliferation
  • periodontal ligaments fibroblasts - slow proliferation
• What need to happen for the regeneration of the periodontal ligament?


  • Periodontal ligament fibroblasts need to colonise root surface first for regeneration of periodontal ligament
  • Osteoclasts need to colonise area before epithelial cells and connective tissue fibroblasts for bone to regenerate

  
• How is connective tissue reattached?

  • Control of movement of cell populations

  • Osseo-conduction: Architectural matrix/scaffold onto which bone may form

  • Osseo-induction: Induction of progenitor cells of the surrounding recipient bed to form new bone

  
• What is the role of the membranein guided tissue regeneration?

  • Creates space
  • Blood clot stabilisation
  • Cell occlusion (epithelium & gingival connective tissue)
  • Cell population (Periodontal ligament fibroblasts & osteoblasts)
  • Epithelial proliferation greatest 1st 14 days
  • PDL and osteoblasts migration peaks 2-7 days falls to normal 3-4 weeks

  
• What membranes are used in guided tissue regeneration?

  From barrier membrane, either:

  • non-degradable: millipore filter, E-PTFE
  • degradable: collagen, polylactic acid, polyglycolic acid, PLA/PLG Copolymers, Oxidised cellulose
• Features of non-degradable membranes?

  • Disadvantage is that a second surgical procedure is required in order to remove it six weeks after placement

  • Demanding and time consuming procedure

  • If recession takes place during healing they can become contaminated
• Features of Degradable membranes?

  • Easier to place

  • no second procedure to remove them

  • biocompatible and non-irritant

  • However, they have unpredictable degradation sometimes causing perforation halting regeneration
• What are uses of guided tissue regeneration?

  - Two/three walled infrabony defects

  - most predictably in class 2 lesions

  - aiming for bone regeneration prior to implant placement