Furcation Classes in Periodontal Disease

Furcation Involvement Classification

• Class I (initial): horizontal loss of periodontal tissue (PD) support not exceeding 1/3 of the width of the tooth
• Class II (partial): horizontal loss of PD tissue support exceeding 1/3 of the width of the tooth but not encompassing the total width of the furcation area
• Class III (total) denotes horizontal “through and through” destruction of the PD tissues in the furcation area
• Class IV: gingiva recession, exposing the furcation opening clinically

Diagnosis

• Examination includes clinical probing and radiographic analysis
• Probing: using graduated curved periodontal Probe, explorers or small curettes (Fig7)
• Special furcation probes (Naber probes) are available with millimeter indications
• Clinical examination of furcas on proximal tooth surfaces may be more difficult due to neighboring teeth and contact area
• Mesial furcation should be probed from the palatal aspect of the tooth, while the furca in the distal surface is probed from either the buccal or the palatal aspect (Figs 7-8)

Radiographic Analysis

• Radiographs must be obtained to confirm findings made during probing of a furcation-involved tooth
• Examination includes both paralleling “periapical” and vertical “bite-wing” radiographs
• Location of the interdental bone and bone level within the root complex should be examined (Fig9)

Situations of Inconsistent Findings

• Clinical probing and radiographs may show inconsistent findings
• Localized but extensive attachment loss within the root complex of a maxillary molar may not appear in the radiograph due to superimposition of the palatal root and remaining bone structures (Fig10)

Differential Diagnosis

• A lesion in the inter-radicular space of a multi-rooted tooth may be associated with problems originating from the root canal or occlusal overload
• Pulpal pathosis may cause a lesion in the periodontal tissues of the furcation
• Vitality of the affected tooth must be tested to differentiate between plaque-associated and pulpal pathosis lesions

Treatment Options

• Root resection/Separation: sectioning of the root complex and maintenance of all roots
• Root resection: removal of one or more roots from a multi-rooted tooth to allow access to the furcation area for cleaning (Fig3.A)
• Tooth division: indicated for extensive furcation involvement of lower molars where bone loss around both roots is similar
• Hemisection: indicated for furcation involvement of lower molars where there is extensive bone resorption around one of the roots (Fig3C)

Factors in Selecting Root to be Retained

• Amount of supporting tissues remaining around the various roots
• Stability of the individual roots
• Root and root canal anatomy with respect to endodontic and restorative treatment procedures
• Periapical condition of the roots
• Position of the various teeth (roots) in the alveolar process in relation to adjacent and opposing teeth
• Oral hygiene of the patient
• General health of the patient
• Neighboring teeth should be healthy

Guided Tissue Regeneration (GTR) Techniques

• Aim: formation of new connective tissue attachment consisting of periodontal ligament fibers embedded into bone & cementum
• Barrier membrane adapted to fit over the defect & the root of the tooth to guide fibroblast cell of periodontal ligament to contact the root surface during healing (Fig4)
• Membranes: non-resorbable and bioresorbable

Bone Substitute Materials or Bone Grafting

• Autogenous bone grafting: grafts transferred from one position to another within the same individual
• Allografts: grafts transferred between genetically dissimilar members of the same species
• Xenografts: grafts taken from a donor of another species
• Alloplastic materials: synthetic or inorganic implant materials used as substitutes for bone grafts
• Examples: hydroxyapatite, tricalcium phosphate
• Combinations of GTR with bone grafts have been shown to have some advantages over either technique used alone