8- bone surgery

What is bone surgery? Alveolar bone loss caused by periodontitis means? (3)

Procedure to change alveolar bone and fix deformities caused by the periodontal disease or by related factors, such as exostosis and extrusion

Irregular alveolar profile

Infrabony pockets that are difficult to instrument

No periodontal disease control

Why should you do bone recontouring?(3)

Sanitisable gum and alveolar contour

Solve angular defects and craters

Remove furcation defects

Indications for bone surgery?(3)

Changes in bone morphology and contour of gum

Persistent periodontal pockets

7 Considerations when doing bone surgery?

Bone support of each tooth

Destruction of the alveolar process

Prominences and exostoses

Anatomical spaces or compartments

Muscles and attachment level

Arteries (maxillary, lingual, sublingual, facial, etc.)

Nerves (cranial nerve V: maxillary, mandibula

2 types of bone surgery?

Additive osseous surgery - bone regeneration

Resective (subtractive) osseous surgery - bone recontouring/regularisation

What’s an osteoplasty?

Periodontal pocket eliminated

Remodelling of physiologic bone contour and overlying gingiva

Remodelled bone not part of supporting apparatus - no loss of tooth support

What’s a ostectomy?

Excision of part of supporting periodontal bone to eliminate perio pocket and establish gingival contour

Requires some loss of bone support- amount removed important

5 Indications of osteoplasty?

Deep interproximal pockets in posteriors with blunt bone crest, wavy and irregular contour

Pockets on Vb, L/Pt surfaces where bone resorption results from large walls (bi- and trifurcations)

Tipped 2nd molar due to missing 1st molar (deep V-shaped cut)

Pocket removal to prevent recurrent abscesses, even if a raised recession remains

Remove Vb and L concavities for better access for hygiene

3 Indications of ostectomy?

Interproximal bone craters —> the VB + L spines remain, and the interproximal portion disappears

Extremely deep interproximal pockets

Superficial infrabony pockets and those where reattachment attempts have failed

Anatomy of alveolar bone crest - what 4 types?

Ideal = interdental bone more coronal interproximally than on B/L + gradual curved slopes between interdental peaks

Flat = interdental and radicular bone at the same height

Positive = interdental bone higher than radicular bone

Negative = interdental bone more apical (lower) than radicular bone

4 Indications for resective bone surgery?

Infrabony pockets where bone removal achieved without sacrificing supporting bone

Deep proximal infrabony pockets requiring bone removal for pocket elimination

Suprabony pockets with irregular bone crest heights- recurrence

Bi- or trifurcations for thorough cleaning

3 Advantages of resective bone surgery

Prevents recurrence of infection and inflammation

Remodels alveolar crest

Restores fibres structure and function

4 Disadvantages/limitations of resective bone surgery?

Buccal recession

Reverse architecture

Sacrifice of Buccal bone

Inadequate interdental space between molars

What is an angular defect? Depends on?

bone profile lies obliquely to root profile leaving undermined groove along root, esp interdentally

Depend on number of bony walls

• 3 wall, 2 or 1

Circumferential defect

Circular wall of destruction

Bone/osseous craters

Concavities in interdental crest confined between B and L walls

2 circular defects connect

Hemiseptal defect

A crater that loses one of its external walls

Types of craters

CLASS 1 (2-3 mm): Normal- minimal reduction in PT

CLASS 2 (4-5 mm): Concave- minimal red in PT (2-3mm) and VB

CLASS 3 (6-7 mm): Advanced lesion- minimal red in VB, up to level of PT furcation (sacrifices support)

CLASS 4: Concave with very thin VB and PT walls- red similar to class 3 but with less volume

Root trunk (CEJ-Furcation)

Superficial craters (1-2 mm)—> SHORT trunk: 3 mm max/ 2 mm mand

Medium craters (3-4 mm) —> MEDIUM: 4 mm max/ 3 mm mand

Deep craters (+5 mm) —> LONG: +5 mm max/ + 4mm mand

Furcation grades

Grade 1- up to 3mm

2- over 3mm without passing through PT

3- through and through

Furcation Prognostic and contributing factors (4) + 6

• Anatomical characteristics

Furcation width

Root trunk length

Root concavities

Cervical enamel projections

Enamel pearls

Dentin and/or cementum bridges

• Difficult access for instrumentation

• Persistent microflora

• Unpredictable results

Treatment grade 1 furcation

SRP

Pocket elimination

Odontoplasty

Treatment furcation grade 2 (5)

Odontoplasty

Tunnelling

Root resection/amputaion

Guided tissue regeneration

Extraction

Treatment furcation grade 3

Tunnelling

Root resection/amputation

Extraction

What factors 8 influence treatment of furcation?

Degree of furcation involvement

Crown-root ratio

Root separation

Strategic value of the tooth

Residual mobility

Oral hygiene options

Long-term prognosis

Implant evaluacion