Furcation involvement and guided tissue regeneration

• Definition of furcation involvement?

  Extension of periodontitis with connective tissue loss in a vertical and horizontal direction between the roots of multi rooted teeth
• Detecting furcations

  Measure individually for each individual furcation entrance with a furcation probe, eg. nabbers
• Who wrote the furcation classification?

  HAMP et al 1975
• Furcation classification

  1 = loss of perio support 1/3 tooth width

  2 = loss of perio support MORE than 1/3 tooth width but not through and through

  3 = through and through
• What anatomical considerations are there?

  • tooth type
  • root number and morphology
  • Root trunk and morphology

  
• Upper molars ?

  • 6.7.8 have 3 root which are: MB, DB and P
  • 3 furcation entrances
  • 0.4% have 4 roots
  • Usually 3-5mm from CEJ
• Fused roots?

  • upper molars
  • Difficult to clean and debride the grooves
• Anatomical considerations for multi rooted teeth?

  • usually more posterior = difficult access
  • Broad contact points = impede access
  • M and D restorations are adjacent to furcation entrances = margin positions and finishes are critical
• Anatomical considerations for altered anatomical features?

  • pearls
  • Spurs
  • Grooves
• Anatomical considerations for canine fossa

  an external root surface concavity, can play a role in early involvement of pocket formation
• Upper molar furcation access?

  Buccal root = furcation buccally

  MB root = broader, furcation accessed mesio palatally

  Palatal root = usually situated distally, larger diameter, access furcation via DB aspect

  
• Maxillary premolars ?

  • 40% 2 roots which are buccal and palatal
  • Furcation is usually in the middle or apical 1/3 of root complex
  • 3-6% have 3 roots
• max premolars 3 entrances are

  7mm from CEJ
• Lower molars ?

  • 6,7,8 have 2 roots which are M and D
  • 1.4 - 7.5% have 3 roots
  • furcation entrances 3-4 mm from CEJ
• Can canines and incisors have more than one root and so a furcation entrance?

  YES!
• Maxillary molar furcation entrance widths

  Mesial > distal > buccal
• Mandibular molar furcation entrance widths

  Lingual > buccal
• How wide are furcation entrances ?

  60% less than 0.75mm
• Why is the width of a furcation entrance a problem?

  60% of entrances are less than 0.75mm and the blade of the graceys is 0.75mm
• Concavities inside furcations of maxillary molars ?

  • MB root 94% (0.3mm deep)
  • Palatal root 17%
  • DB root 31%
• Concavities inside furcations of mandibular molars?

  • Mesial root 100% (0.7mm deep)
  • Distal root 99% (0.5mm deep)
• Concavities of premolars

  • canine fossa
  • Buccal root 0.5mm deep
• Aims of Tx?

  1. eliminate microbial plaque from the affected root complex
  2. Facilitation of self performed plaque control
• Non surgical Tx of furcation Lesions?

  • OHI w focussed attention to ID and subgingival plaque
  • PMPR
  • RSD
• surgical Tx of furcation Lesions can be done by two general principles?


  • surgically removing or repositioning of soft tissue to expose furcation
  • Re contour furcations "furcoplasty" in class 1/2
• Surgical options for opening furcation to make cleansable?

  1. tunnelling in class 2 and 3
  2. Root amputation in class 2 and 3
  3. Hemisection in class 2 and 3
  4. Premolarisation in class 2 or 3
• Closing the furcation?

  Guided tissue regeneration in class 1/2 defects

  • buccal and lingual of lower molars
  • buccal of upper molars
• XLA of furcation involved teeth ?

  • those with +++ attachment loss
  • Inability to provide anatomy that allows for optimal OH
  • keeping tooth = RF for long term prognosis of overall Tx
• Tissue healing

  via RSD and surgical resection of pocket lining
• Tissue healing with root interface occurs via

  long junctional epithelium formation +/- connective tissue in the base of the defect
• What cells are involved in the healing process?

  epithelial cells = rapid proliferation

  CT Fibroblasts = rapid proliferation

  Osteoblasts = slow proliferation

  PDL fibroblasts = slow proliferation
• How do cells carry out the healing process?

  1. PDL fibroblasts need to colonised root surface for regeneration of PDL
  2. Osteoclasts need to colonise are BEFORE epithelial cells and CT fibroblasts to allow bone regen

  AKA : slow proliferating cells --> quick
• Connective tissue attachment?

  • control of movement of cell pop:
  • 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
• Membrane role in healing ?

  • creates space
  • stabilises blood clot
  • Cell occlusion = ep and gingival CT
  • Cell population = PDL fibroblasts and osteoclasts
• When is epithelial proliferation greatest

  first 2 weeks
• PDL and osteoblast migration peaks and falls when ?

  2-7 day peak and falls to normal at 3-4 weeks
• What membrane types are used in GTR

  All are barrier membranes which are broken into non degradable and degradable. Each have many options seen below

  
• Non degradable membranes?

  • 2 surgical procedures needed to place and remove 6 weeks later
  • Demanding and time consuming
  • Recession takes place during healing so they can become contaminated
• Degradable membranes ?

  • easier to place
  • Dont need secondary procedure to remove
  • V biocompatible
  • Non irritant
  • Unpredictable degradation profile can lead to perforation and halting of regen
• Uses of GTR?

  1. 2 or 3 walls infrabony defects
  2. Tx of furcation defects in class 2 lesions
  3. Alveolar ridge defects aiming for bone regen before implant placements