8- bone surgery

What is bone surgery?

Procedure to change,alveolar bone and free it from deformities induced by the periodontal disease process or by related factors, such as exostosis and dental extrusion.

Alveolar bone loss caused by periodontitis means-

Irregular alveolar profile

Infrabony pockets that are difficult to instrument

No periodontal disease control

Why should you do bone recontouring?

Sanitise 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

Considerations for 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

Physiologic contour of bone and overlying gingiva remodelled

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

Indications of osteoplasty?

Deep interproximal pockets in posterior teeth with blunted bone crest, wavy and irregular contour

Pockets on Vb, lingual, and 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 lingual concavities for better access for hygiene

Indications of ostectomy?

Interproximal craters in bone —> the VB and LING spines remain, and the interproximal portion disappears

Extremely deep interproximal pockets

Superficial infrabony pockets and those where reattachment attempts have failed

Anatomy of bone and how it effects periodontal disease?

Ideal anatomy: more coronal on the interproximal surfaces than on the buccal and lingual surfaces, with gradually curved slopes between the interdental peaks.

Flat anatomy: interdental bone is at the same level as the radicular bone

Positive anatomy: radicular bone is apical to the interdental bone

Negative anatomy: interdental bone is located more apical than the radicular bone

Indications of bone surgery?

Intra alveolar pockets where bone removal doesn’t sacrifice useful bone o]for affected/adjacent tooth

Intra alveolar proximal pockets where bone removal is indispensable to eliminate pocket

Supra alveolar pockets with marked differences in crest bone height (favors recurrence)

Bi or trifurcations to enable thorough cleaning

Advantages of bone surgery

Prevents recurrence of infection and inflammation

Remodels alveolar crest

Restores fibres stricter and function

Disadvantages of 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

Bone/osseous craters

Concavities in interdental crest confined between B and L walls

Hemiseptal defect

A crate 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) —> LENGTH: +5 mm max/ + 4mm mand

Types of furcations

Grade 1- up to 3mm

2- over 3mm without passing through PT

3- through and through

Furcation Prognostic and contributing factors

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

Odontoplasty

Tunnelling

Root resection/amputaion

Guided tissue regeneration

Extraction

Treatment furcation grade 3

Tunnelling

Root resection/amputation

Extraction

What factors 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