Dr. Nitin Tomar

Reader, Dept. Of Periodontology

Subharti Dental College and Hospital, SVSU, Meerut

CONTENTS Introduction Defination Clinical features Microscopic features Terminology Anatomy Classification Anatomic considerations Etiology of furcation invasions Diagnosis Epidemiology

Treatment scaling and rootplaning obliteration of furcation gingivectomy/apically positioned flap furcationplasty tunnel proceedure resective periodontal proceedures regenerative proceedures tooth extraction prognostic factors conclusion

Molars are the tooth type demonstrating the highest rate of

periodontal destruction in untreated disease and suffer the highest

frequency of loss for periodontal reasons. Furcation involvement

is defined as bone resorption and attachment loss in the

interradicular space that results from plaque-associated

periodontal disease. Such a condition is reported to considerably

increase the risk for tooth loss. Therefore, furcation defects

represent a formidable problem in the treatment of periodontal

disease, principally related to the complex and irregular anatomy

of furcations..

Moreover, the responsiveness to therapy may be complicated

by the presence of a greater radicular surface potentially

offered to bacterial toxins and calculus buildup ,as compared to

defects surrounding single-rooted teeth. Once the lesion has

established, the discrepancy in extent between the root surfaces

and the periodontal soft tissues facing the bacterial insult may

be responsible for a reduced healing response. Finally, the

distal location in the arch and the difficult access may

conceivably impair both self-performed and professional

plaque control procedures in the furcation area, limiting their

effectiveness

Definition :

The term Furcation involvement refers to the invasion of the bifurcation and trifurcation of multi-rooted teeth by periodontal disease.

Glossary of periodonlal terms defines Furcation as "the area of a multi-rooted tooth where the roots diverge". It defines a furcation invasion as the "pathologic resorption of bone within a Furcation”.

The mandibular first molars - most common sites and maxillary premolars - least common

increases with age.

Clinical Features

Microscopic Features

Terminology : Root complex is the portion

of a tooth that is located

apical of the cementoenamel

junction (CEJ) i.e., the

portion that normally is

covered with a root

cementum

root trunk

root cone

The furcation is the area located between individual root cones and it refers to the anatomic area of a mulrirooted tooth where the roots divide or diverge from the common root trunk.

roof which is the base of the root trunk and contains bifurcation ridge.

flute -usually concave or grooving of the root trunk, extending from the cervical line and blending into the actual furca.

inter-radicular area or the area of the root separation or furcation chamber,

Furcation entrance the transitional area between the undivided and the divided part of the root.

Furcation fornix is the roof of the furcation.

Degree of separation : the

angle of separation between

two roots (cones).

Divergence : is the distance

between two roots

Coefficient of separation : the

length of the root cones in

relation to the length of the

root complex.

Anatomy

Maxillary molars:

The first and second molars

most often have three roots.

The mesiobuccal root is

normally vertically

positioned while the

distobuccal and the palatal

roots are inclined.

The cross sections of the

distobuccal and the palatal

roots are generally circular.

The distal surface -

mesiobuccal root - concavity

which is about 0.3 mm deep

(Bower 1979) - "hour-glass"

configuration.

The first molar has a shorter root trunk than the second molar.

In the first molar the mesial furcation entrance - 3 mm from buccal - 3.5 mm and the distal - 5 mm apical of CEJ (Abrams & Trachtenberg 1974, Rosenberg 1988).

Furcation fornix is inclined - the mesiodistal plane.

The buccal furcation entrance is narrower than its distal & mesial counterparts.

The degree of separation between the roots and their divergence - 1 > 2 > 3 molar.

Maxillary premolars

In about 40% of cases the maxillary first premolars have two root cones.

A concavity- 0.5 mm deep- buccal root.

located in the middle or in the apical third of the root complex.

The mean distance between CEJ and the furcation entrance - 8 mm.

The width of the furcation entrance - 0.7 mm.

Mandibular molars

First and second molars the root complex almost always includes two root cones.

The mesial root is larger than the distal.

The mesial root has a position which is mainly vertical while the distal root projects distally.

The root trunk of the first molar is often shorter than the trunk of the second molar.

The lingual entrance - apical of CEJ (> 4 mm) than the buccal entrance (> 3 mm).

Furcation fornix is inclined in the buccolingual direction.

Buccal furcation entrance - < 0.75 mm wide & lingual entrance - > 0.75 mm in most cases (Bower 1979).

The degree of separation & divergence between the roots decreases from the first to the third molar

Classification

Glickman (1958)

Staffileno (1969)

Goldman and Cohen's (1980)

Heins & Canter (1968)

Easley & Drennan’s classification (1969)

Hamp et al (1975)

Lindhe & Nyman (1975)

Ramjford & Ash (1979)

Riccheti (1982)

Lindhe (1983)

Eskow and Kapin (1984)

Tarnow & Fletcher (1984)

Fedi (1985)

Hamp and Nyrnan (1989)

Basaraba (1990)

Hou et al (1998)

Glickman (1958) Grade-I: When there is soft-tissue lesion or pocket extending into the flute

of the furcation, but the inter-radicular bone is intact. This involvement of the periodontium in the furcation area is without manifested radiographic evidence of bone loss.

Grade-II: Loss of inter-radicular bone & pocket formation of varying depths into the furcation but not completely through the opposite side of the tooth.

Grade-III: Complete loss of inter-radicular bone with radiographic evidence presenting a small triangular radiolucency at the furcation area. There is a pocket formation that is completely probable to the opposite side of the tooth. However, the furcation is not visible clinically.

Grade-lV: Same features as those of Grade III except that loss of periodontal attachment & gingival recession has made the furcation clearly visible to a clinical examination.

Glickman (1958)

Hamp et al (1975)

Degree I / class 1: represents horizontal attachment loss of less

than 3 mm within the furcation involvement.

Class-II: represents horizontal loss greater than 3 mm but not

encompassing the total width of the furcation.

Class-III: denotes horizontal through and through destruction.

This classification is similar to that described by Lindhe &

Nyman (1975).

Hamp et al (1975)

Eskow and Kapin (1984) - vertical loss in thirds of inter radicular

loss.

Tarnow & Fletcher (1984) – millimeters.

Subclass A: Vertical destruction to one third of the total inter

radicular height (1 to 3 mm).

Subclass B: Vertical destruction reaching two thirds of the inter

radicular height (4 to 6 mm).

Subclass C: Inter radicular osseous destruction into or beyond the

apical third (> 7 mm).

Anatomic considerations: 1) Root trunk length and Entrance width

2) Concavity of the inner surface of exposed roots

3) Degree of separation of the roots

4) Bifurcational ridges

5) Enamel projections

6)Accessory pulp canals

1) Root trunk length and Entrance width:

short root trunk – furcation become involved early in the

disease process.

long root trunk – furcation -invaded later - more difficult to

reach and instrument.

First molars generally have shorter root trunks than second

molars.

2) Concavity of the inner surface of exposed roots:

exhibit - an occluso-apical direction.

This may make instrumentation for calculus removal and root planing almost impossible.

First molars frequently have plaque harboring concavities, especially the mesiobuccal roots of maxillary molars and the mesial roots of mandibular molars. This may allow bacterial plaque, its toxins and ultimately calculus to penetrate for into the root surface making the removal difficult.

3) Degree of separation of the roots:

Wide separation of the roots improves access, thereby facilitating instrumentation.

First molar furcations are frequently wider than those of second molars.

4) Bifurcational ridges:

Buccal and lingual ridges were found in 63% of the mandibular molars. These ridges resulted in the roof of the furcation being located more coronally than the entrances.

5) Enamel projections:

AAP - enamel pearl is "a small focal mass of enamel formed apical to the CEJ", while enamel projection is "an extension of the cervical enamel margin either toward or into the root furcation area ".

Master & Hoskins (1964)

grade I, short CEP from CEJ

grade II, longer CEP and approaches the furcation area

grade III, CEP that extends directly into the furcation.

These occur in approximately 15% of molars. They favor plaque accumulation and must be removed to facilitate scaling and root planing.

6) Accessory pulp canals:

The presence of accessory pulpal canals in the furcation

area may extend pulpal inflammation to the furcation. 28% to

59% of the molar have been found to have accessory pulp

canals.

Etiology of furcation invasions Primary factor - Bacterial plaque

Predisposing factors - Anatomical considerations

Root concavities

Enamel pearls and projections

Accessory pulp canals

Bifurcation ridges

Location of furcation relative to CEJ

Location and diameter of furcation entrance

Extension of inflammatory periodontal disease

Isolated molar furcation invasions

Trauma from occlusion

Pulpal periodontal disease

iatrogenic cofactors

Root fractures involving furcations

Trauma from occlusion:

predisposing cofactor - more rapid formation of furcation involvement is controversial.

The molar furcation is unique compared with a single rooted tooth in that its periodontal ligament between the crest of the interfurcal bone & the dome of the furcation is aligned in a horizontal rather than a vertical plane. Thus, even slight increase in centric occlusal forces would have the same crushing effect on periodontal ligament as destructive, lateral forces on a PDL aligned in a vertical plane.

Because molar teeth are closer to the condyle the forces generated on them are much higher than those on more anterior teeth. Therefore, if trauma from occlusion combined with deeper inflammation in close proximity to a furcation results in rapid loss of attachment than from inflammation alone.

The greater susceptibility of molar teeth to traumatic forces could be a reason for the formation of an isolated furcation involvement.

Pulpal periodontal disease:

The high percentage of molar teeth with patent accessory canal opening into the furcation suggests that pulpal disease could be an initiating cofactor in the development of furcation involvement.

Furcation involvement - combined endodontic periodontic defect.

Accessory canals connecting the pulp chamber floor to the furcation have been found in 36% maxillary first molars, 12% of maxillary second molars, 32% of mandibular first molars and 24% of mandibular second molars.

latrogenic cofactors:

Overhanging restorations harbor - dental plaque - periodontal inflammation and attachment loss.

A study of molars with and without crowns and proximal restorations found that molars with restorations had a higher prevalence of furcation involvement and greater attachment loss than molars without furcation involvement.

Root fractures involving furcations:

Rapid, localized, alveolar bone loss is often seen associated

with vertical root fractures.

If these root fractures involve the trunk of a multi-rooted

molar and extend into a furcation, a rapidly forming isolated

furcation defect can result.

The prognosis for these situations is poor and usually results

in loss of the tooth.

DIAGNOSIS

Clinical diagnosis

Radiographic diagnosis

Differential diagnosis

CLINICAL DIAGNOSIS:

Cardinal symptoms:

Redness and swelling

increased temperature

pain and loss of function

In advanced cases, the close topography of the roots of a multirooted tooth may even promote the development of a painful periodontal abscess.

may be perceived elongated and mobile which

may result in impaired function.

increased bleeding tendency upon gentle probing

or occasional suppuration

specific for inter radicular periodontitis.

Clinical probing:

accessible for examination using a curved graduated periodontal probe, an explorer or a small curette.

In maxillary molars - mesial furcation should be probed from the palatal aspect of the tooth.

The distal furcation entrance of the maxillary molar - probed from either the buccal or the palatal aspect of the tooth.

Straight periodontal probes are used clinically to determine the height and width of furcation involvement - less useful for determining the degree of horizontal involvement.

Tibbetts (1969) recommended the use of a curette to negotiate the curve of furca and Carranza (1979) advocated the use of a curved Cowhorn explorer or Nabers probe.

Carranza stated that furcas can best be evaluated with a curved Nabers probe.

The probing of vertical attachment loss on the roots adjacent

to furcation involvement is also important. Vertical attachment

loss on the adjacent roots should be probed at the furcation line

angle of each root, angling the probe somewhat into the furca.

To determine the bone contours associated with furcation

involvement more accurately, transgingival probing or bone

sounding can be accomplished through anesthetized soft tissues.

This technique has been shown to yield accurate

measurements when compared with those made at the time of

open flap surgery (Greenberg 1976).

ATTACHMENT LOSS:

A more specific feature of the furcation lesion is the development of horizontal attachment loss which means that the pocket has a lateral extension. The molar furcations present a complex anatomical configuration that makes recording pocket depths and attachment levels more difficult. Also the clinical probing is generally hampered by the soft tissues bordering the areas to be probed.

Clinical attachment levels are usually measured with a straight_probe.

It is obvious that a straight probe would not be able to reach_the_fhll_extent of furcation defect because the initial vertical pocket curves horizontally into the furca.

curved Nabers probe or a fine curete is very useful. The curvature of these instruments allows them to be passed under the roof of the furca and to measure the horizontal and vertical degree of involvement.

Carranza stated that furcas can best be evaluated with a curved Nabers #2 probe. Also there are calibrated furcation probe ZA - 2 with calibrations in 2 mm increments, ZA - 3 with calibrations in 3 -mm increments.

Tal (1982) described a probe which permits direct

measurements of the depth of the furcal defects. It consists of a

millimeter scale and a flexible metal spring tube ensheathing a

rigid stilleto, 0.3 mm thick.

The probe should be directed along the hard surface

demarcating the furcation in order to avoid deviation into the

furcal soft tissues. The buccal furca of the maxillary molars and

the buccal and lingual furcas of the mandibular molars are

normally accessible for examination by clinical probing.

The clinical examination of furcas on the approximal tooth surfaces may be more difficult when neighboring teeth are present, especially if the contact area between the teeth is large. This is particularly the case in maxillary molars.

The clinical examination of maxillary premolars is often difficult due to limited access for probing. It may not always be possible - until flap is raised in an explorative (surgical) procedure in the area.

The probing of vertical attachment loss on the roots adjacent to furcaticn involvement is also important. Traditionally, before searching for Furcation invasions, probing of the periodontal tissues is exerted at 4 sites of every tooth present, mesiobuccally midbuccally, distobuccally and midlingually (Nyman and Lindhe, 1997). In case of probing only 4 sites, lesions at the mesiopalatal furcations of 1st and 2nd maxillary molars or at upper premolars may be overlooked. Kuhner and Raetzke (1991) stressed that especially at maxillary molars, 6 measurements per tooth provide considerable more information on the extent of the disease than 4 measurements.

Radiographs:

Furcation involvements are often first detected on radiographs if they have been made before probing measurements are obtained.

Maxillary furcations are not readily seen in radiographs taken at right angles to the teeth and suggested that better visualization of the furcations is possible by varying the angle of the beam.

They recommend using a film holder to allow the use of long cone, right angle techniques.

Lateral and vertical x-ray beam deviation can grossly distort the furcation image leading to false interpretations.

Glickman found that clinically significant tissue changes in the furcation often are not detected by radiographs.

On x-ray films of maxillary molars, a small, triangular, radiolucent shadow is sometimes seen over the mesial or distal roots in the proximal furcation areas, which has been called furcation arrow.

The association of this image with deep grade II or grade III FI was significant compared with uninvolved furcations, but the arrow was not seen in more than half of the sites with a deep grade II FI and in slightly less than half of grade III sites. Thus, it appears that radiographs alone do not detect FI with any predictable accuracy and that probing the furcation area is necessary to confirm the presence & severity of FI.

Three diagnostic criteria suggested to assist in radiographic detection of furcation involvement:

1) The slight radiographic change in the furcation area should be investigated clinically, especially if there is bone loss on adjacent roots.

2) Diminished radiodensity in the furcation area in which outlines of bony trabeculae are visible suggests furcation involvement.

3) Whenever there is marked bone loss in relation to a single molar root, it may be assumed that the furcation is also involved.

Differential diagnosis :

A lesion in the inter radicular space of a multi-rooted teeth may be associated with problems originating from the root canal or be the result of occlusal overload.

In order to difference between the two lesions the vitality of the affected tooth must always be tested. If the tooth is vital, a plaque-associated lesion should be suspected. If the tooth is non vital, the furcation involvement may have an endodontic origin & in such case proper endodontic treatment must always precede periodontal therapy.

In fact, endodontic therapy may resolve the inflammatory lesion, soft & hard tissue healing occur & the furcation defect disappear. If signs of healing of a furcation defect fail to appear within 2 months following endodontic treatment, the furcation involvement is probably associated with marginal periodontitis.

Trauma from occlusion :

Forces elicited by occlusal interferences eg; bruxers and clenchers may cause inflammation and tissue destruction or adaptation within the inter radicular area of a multi-rooted tooth.

In such a tooth a radiolucency may be seen in the radiograph of the root complex. The tooth may exhibit increased mobility. Probing however fails to detect in involvement of the furcation.

In this particular situation, occlusal adjustment must always precede periodontal therapy. If the defects seen within the root complex are of "occlusal" origin, the tooth will become stabilized and the defects disappear within weeks following correction of the occlusal overload.

EPIDEMIOLOGY

In untreated periodontitis, the majority of sites losing

attachment are Molars (Lindhe et al 1989).

Molars represent the tooth type responding least favorable to

therapy (Kaldahl et a 1990. Loos et al 1989. Nordland et al 1987).

Molars are at greater risk for extraction compared with other

tooth types (Goldman et al 1986. Hirschfeld and Wasserman

1978. McFall 1982, Wood et al 1989).

The greater rate of mortality observed with molars may

partly be explained by the presence of furcations.

Maxillary molars are more frequently affected than mandibular molars.

Furcation involvement is more frequently detected in smokers (720/o) than in non-smokers (36%).

Molars with crowns or proximal restorations have significantly higher percentages of furcation involvement (52-63%) compared with molars without -restorations (39%) (Wang et al 1993).

TREATMENT

The major principle of treatment of involved furcas is to eliminate the etiologic factor, the furcation perse, whenever possible and to create a predictably maintainable environment. The prognosis and modality of therapy for multirooted tooth with loss of periodontal attachment in the inter radicular area depends on the following factors.‘

1. The extent of lost attachment apparatus in a horizontal and vertical direction within the furca and the number of furcas involved in a multi rooted tooth.

2. The degree of internal furcation involvement within a maxillary molar.

3. Morphology of the inter radicular septum.

4. The length, number, shape and divergence of the roots.

5. The dimension of the root trunk and relationship of the level of the inter radicular septum to adjacent osseous structures.

6. Relationship and level of the adjacent osseous and soft tissues.

7. Root proximity to the adjacent teeth.

8. Access to the denuded inter radicular area to plaque control procedures.

9. Tooth vitality

10. Apical extent of root caries

11. Strategic importance of the tooth.

12. Tooth mobility

13. Quality of prior endodontic therapy

14. Restorative requirements for the tooth and case

15. Occlusion and interarch relationship

16. Anatomic considerations such as the external oblique ridge

and tori.

17. Tooth inclination and position relative to basal bone

18. Etiology of lesion i.e. pulpal, periodontal, combined or

iatrogenic.

Three broad strategies of furcation therapy are:

I. Maintenance of the existing Furcation:

Scaling and root planing

Obstruction of the Furcation

II. Increasing access to the Furcation:

Gingivectoiny/Apical positioned flap

Odontoplasty .

Osteoplasty/ostectomy

III. Elimination of the Furcation

Root amputation/ Tooth resection

Bicuspidization

Different therapeutic alternatives are available relative to different degrees of involvement

Degree of involvement Therapy

grade I Scaling and curettage/gingivectomy odontoplasty

Furcation plasty

grade II degree1 closed scaling and rootplaning

Openscaling and rootplaning with replaced flaps

Furcation operation

degree II closed scaling and rootplaning

Openscaling and rootplaning with replaced flaps

Creating a grade IV tunnel

Tunnel preparation

GTR

Root resection

Grade III closed scaling and rootplaning

Openscaling and rootplaning with replaced

flaps

Creating a grade IV tunnel

Tunnel preparation

GTR

Root resection

SCALING AND ROOT PLANING :

It can be closed or open.

I Non- surgical/Closed scaling and Root Planing:

sufficient for Grade I and shallow Grade II furcations.

Healing must result in a furcation morphology that is optimal for good patient plaque control, otherwise other therapeutic methods must be used.

Closed scaling and root planing may be the treatment of choice if surgery is contraindicated for medical or psychological reasons.

II Surgical/Open Scaling and Root planing:

If sufficient subgingival access is not possible with a closed

approach, for furcated molars with deep lesions, then open scaling

using flap procedure such as modified widman flap yields more

effective calculus removal with Furcation involvement.

Thus replaced flap results in some pocket reduction by

formation of a long junctional epithelial adhesion.

Fleischer et al (I989) demonstrated that level of experience play an important role in furcation debridement, especially with closed debridement.

Maria et al (1986), Parashis et al (1993) and Fleischer et al showed more effective calculus removal achieved with open than closed scaling and root planing.

Using clinical parameters, Kalkwarf et al (1988), Schroer et al (1991) and Wang et al (1994) didn’t observed any advantage of open debridement over closed.

The type of instruments used also plays a significant role in more thorough furcation debridement (Fleischer et al 1989). Ultrasonic tips and curets have been found to be equally effective in wide furcations, but ultrasonic tips were more effective in narrow ones (Matia et al 1986).

According to Bowers (1979) in 58% of upper and lower first molars, the furcation entrance diameter is narrower (<0.75 mm) than the width of conventional periodontal curette. Hence the use of curettes alone would result in inadequate debridement of many furcation areas .

Leon and Vogel (1987) reported that the use of ultrasonic scalers was more effective than hand scaling in close debridement of advanced furcations.

The large dimensions of conventional ultrasonic-tips inhibit entry into the furcation in some cases. So many new designs of furcation tips were designed and developed and were shown invitro to be superior to conventional sonic/ultrasonic inserts with greater accessibility and ease of instrumentation in furcation areas

Demarco furcation curette

Oda and Ishikawa (1989) designed a new ultrasonic scaler tip made of acid resistant stainless steel. The end of the tip was spherical (0.8 mm in diameter) to protect the root surfaces and soft tissue injury and improve contact with the root surfaces. The tip was in the shape of a spiral with a radius of curvature of about 9 mm and were available in clockwise and anticlockwise direction.

Kocher et al (1998) developed a sonic sealer set with diamond coated ellipsoid luminal tips (bud shaped tips) with length 3 mm. diameter 1.5 mm. Diamond grit size 45 µm. They had a shaft design similar to a gracey 13/14.

Parashis et al (1993) used a rotary diamond bur to remove calculus deposits in the furcation area after surgical exposure. This method was found to be best in removing calculus from furcations, especially in the flute areas and when the furcation entrance measured <2.4 mm.

Scaling and root planing produce good clinical results during initial stages (Grade I) of furcation involvement. However long term clinical studies have shown unfavourable results of conservative non-surgical and surgical therapy in deep furcation involvement.

Because of the difficulty in performing adequate debridement in furcations by mechanical means, many chemotherapeutic agents have been, used as adjunct locally.

Needleman and Watts (1989): 1% metronidazole gel irrigation

Nylund and Egelberg (1990): 50 mg/ml Tetracycline irrigation every 2nd week for 3 months.

Minabe et al (1991): Tetracycline immobilized in a cross-linked collagen film.

Tonetti et al (1998): Tetracycline impregnated fibers.

did not have any significant advantage, contrary to irrigation, a slow sustained release of Tetracycline exerted a significant adjunctive effect, but only for the first 3 months.

Tracey M. Vest (1999) - reported that administration of

postsurgical antibiotics did not produce statistically superior

osseous healing of Class II furcation defects.

Del Peloso Ribeiro E (2006) - reported that use of

topically applied povidone-iodine (polyvinylpyrrolidone and

iodine [PVP-I] as an adjunct to subgingival instrumentation

does not provide additional benefits.

OBLITERATION OF THE FURCATION - OCCLUSIVE BARRIER

filling of advanced furcation defects - biocompatible material - anatomic niches - bacteria accumulate..

Potential advantages of an occlusive barrier:

Easy to place.

Doesn’t require a suture for stability.

Elimination of a second stage procedure

Epithelial attachment.

Doesn’t require complete coverage by the gingival flap

Bacteriostatic.

Lower cost.

No chance of transmission of viral infection.

Different materials which have been used:

Amalgam

Polymer – reinforced zinc oxide eugenol

Resin ionomer cement

Glass ionomer cement

Van Swol et al (1989) showed that when compared

to amalgam, the tissue reponse was far superior to glass ionomer.

Charles R. Anderegg (2000) - showed that teeth with hopeless prognosis might be retained by decreasing probing depths, bleeding upon probing, and mobility when furcation areas are sealed with a resinionomer

The use of an occlusive barriers has potential use in the treatment of maxillary molar furcation defects because regenerative treatment of maxillary molars are more difficult due to the multiple root anatomy and multiple furcation entrances.

Technique of using glass ionomer or resin ionomer to eliminate furcation defects.

A study by Reddy KP, concluded that glass ionomer restorative material may be effective as an occlusal barrier when treating maxillary molar

compound matrix - lingual aspect prior to packing the glass-ionomer cement.

patients - placed on a 3 month maintenance schedule

INCREASING ACCESS TO THE FURCATION :

Gingivectomy/Apical Positioned Flap :

Reducing or eliminating the soft tissue pockets over the

furcation region increases access for plaque control and allows

resolution of periodontal inflammation.

Gingivectomy or apically repositioned flaps may be used.

FURCATION OPERATION/FURCATIONPLASTY :

Odontoplasty i.e. removal of tooth substance in the furcation area in order to widen a narrow entrance of the furca and to reduce the horizontal depth of the involvement.

Osteoplasty - recontouring of bony defects in the furcation area, if indicated.

Repositioning and suturing of the flap

The purpose of the procedure is to establish a condition in the dentogingival region which facilitates self performed plaque control. It results in the establishment of a soft tissue papilia which covers the entrance to the inter-radicular periodontal tissues.

Tunnel Procedure :

intentional creation of a Class III furcation -

entrance accessible for oral hygiene procedure.

very conservative approach.

objective - cleaning the furcal area by the patient

using an interdental tooth brush.

main advantage - avoidance of prosthetic

reconstruction and endodontic therapy.

It can be utilized only when the furcation entrance

dimension is wide enough and coronally located to

allow for an easy utilization of cleaning devices. A

degree of divergence longer than 30" is required.

implemented sometimes in maxillary molars (Hellden et al 1989).In this situation, however one of the three roots may have to be resected to improve accessibility to the furcation area.

During surgery, bone is reshaped to obtain a scalloped morphology and the soft tissues are apically positioned, care must be taken that the space obtained under the roof of the furcation will allow proper plaque removal.

Surgical packs may be applied

Tunneled teeth appear to be at higher risk for the development of caries (Hellden et al 1989).

Furcations treated with resective osseous surgery for tunnel preparation are expected to result jn a slight loss in attachment as a consequence of the therapy.

RESECTIVE PERIODONTAL SURGERIES :

Resective techniques are designed to eliminate the morphological

characteristics and create an area conducive to good oral hygiene.

Root resection : The surgical removal of all or a portion of the root before or after endodontic treatment.

Root amputation: The removal of a root from a multi-rooted tooth.

Hemisection : The surgical separation of the roots in a multi rooted tooth, especially a mandibular molar through the furcation area in such a way that a root or roots may be surgically removed with the associated part of the crown.

The guidelines for periodontal therapy produced by the AAP in

1992 list only root resection and tooth hemisection as resective

treatment of multi-rooted teeth. Root separation is indicated as

the sectioning of the root complex and the maintenance of all.

INDICATIONS FOR ROOT RESECTION AND SEPARATION TREATMENT:

Periodontal Indications :

Severe bone loss affecting one or more roots untreatable with regenerative procedures.

Class II or Class III furcation invasions or involvements.

Severe recession or dehiscence of a root.

Endodontic or Conservative Indications :

Inability to successfully treat and fill a canal

Root fracture or root perforation

Severe root resorption

Root decay

Prosthetic Indications :

Severe root proximity inadequate for a proper embrasure space.

Root trunk fracture or decay with invasion of the biological width.

CONTRAINDICATIONS TO ROOT RESECTION AND SEPARATION

TREATMENT:

General contraindications to periodontal surgery

- Systemic factors

- Poor oral hygiene

Factors associated with local anatomy

- Fused roots

- Unfavorable tissue architecture

Endodontic factors :

- Retained roots endodontically untreatable

- Excessive endodontic instrumentation of retained roots

- Excessive deepening of pulp chamber floor

Restorative factors

- Internal root decay

- Presence of a cemented post in the remaining root

Strategic considerations

- Consider adjacent teeth available for conventional prosthetic restorstion

- Consider removable prosthesis

- Consider implants

Treatment planing criteria (Langer & coauthors, 1981) :

1) Use only teeth with large roots & clinical crowns

2) Avoid small isolated mandibular molars

3) Develop conservative endodontic access

4) Devote special attention to developing a proper occlusal

scheme

5) Provide continual maintenance care

failure of a root-resected tooth - endodontic or technical

complications.

Hence successful root resection therapy requires a careful

multidisciplinary approach including periodontal surgery,

conservative endodontic treatment and prosthetic reconstruction.

The 1989 World Workshop in Periodontics stated that root

resection therapy “is a procedure which should still remain as part

of the periodontal armamentarium” to treat very specific problems

which cannot be solved by any other therapeutic approach and

when the tooth in question has a very high strategic value.

Bicuspidization :

Separation of a two-rooted tooth (mandibular molar) &

restoration of the crown portion of each section has been

described to enhance plaque control & to convert the part of the

tooth most susceptible to caries attack (dentin & cementum in the

furcation) into metal.

Indication : Grade III furcation involvement & divergent

well supported roots.

Disadvantages : Time, expense & attention to detail required

for successful completion of the case.

Endodontic phase :

access opening - small as possible.

Since root fracture and restorative material failure is an important factor in the long term success of resected teeth, any operative procedure that removes intact coronal tooth structure or places excessive pressure within the canal is to be avoided, if possible.

Excessive preparation of the radicular canals and lateral condensation during the endodontic treatment should also be avoided.

Restorative phase : A foundation restoration is the part of the reconstruction that

replaces the missing coronal & radicular tooth structure before placement of a crown.

The purpose of this restoration is to provide proper restoration and

resistance for the subsequent full coverage restoration. It is generally suggested to accomplish crown build up with a

chemically cured composite, by using a dentin adhesive to improve the retention of the material.

In fact, an amalgam restoration may detach more easily after root

separation: further more, when the tooth section is carried out with an open flap amalgam tattoos may occur.

The type of margin of the full coverage restoration is also significant.

Given the limited width of the residual roots, tooth structure showing knife edge finding lines are frequently required to avoid excessive removal of residual root structure.

Surgical phase :

Root separation and resection in the periodontal patients has

been generally described as part of pocket elimination resective

osseous surgery.

Carnevale et al (1995) and Basten et al (1996) suggest that

bone recontouring to recreate a positive architecture and apically

positioned flaps must be employed in order to obtain an

environment conducive to good hygiene and easy dental care.

Failures were more frequent in maxillary resections (33%)

as compared with mandibular resections (23%). These

deficiencies were radiographically detectable in mandible but

detectable in only 38% of maxillary cases.

REGENERATIVE PROCEDURES:

Root conditioning combined with coronally advanced flap procedure.

Placement of bone grafts or bone substitute implants.

Use of organic or synthetic barrier membranes based on the principles of Guided Tissue Regeneration.

Root conditioning is intended to decontaminate, detoxify and demineralize the root surface, removing the smear layer and exposing collagen matrix.

Agents commonly used

- Citric acid

- Tetracycline HC1

- Fibronectin

- Others - EDTA, Detergents, Phosphoric acid, Bile salts.

Acid etching of the debrided planed root surface removes the smear layer on the denuded root surface and exposes Type I collagen chemotactic to fibroblasts.

Polson and Proye 1983 suggested that a fibrin linkage to the exposed collagen fibrils is a precursor to the connective tissue attachment. This fibrin network may serve to prevent apical migration of epithelium allowing migration of periodontal precursor cells to the root.

Crigger et al (1978), Nilveus et al (1980), Bogle et al (1981)- in their respective animal studies have demonstrated increased amounts of new connective tissue attachment in furcation defects following acid conditioning compared with non-acid treated control.

Klinge et al (1985) also noted that root resorption and

ankylosis may occur following citric acid conditioning.

Tetracycline HCl is absorbed to and subsequently desorbed

from conditioned radicular dentin. Antimicrobial activity is

maintained for at least 14 days (Stabholz et al 1993). Tetracycline

also inhibit neutrophils collagenase (Golub et al 1984).

Fibronectin is a glycoprotein component of the extra cellular

matrix its main function is the promotion of cell adhesion.

Aleo et al (1975) demonstrated enhanced fibroblast

attachment to freshly cleaned root surfaces following topical

application of fibronectin.

BONE GRAFTING :

The strong focus on bone formation as a prerequisite for new attachment formation has led to implantation of bone grafts or different types of bone substitutes into furcation defects.

i) Contain bone forming cells (osteogenesis)

ii) Serve as a scaffold for bone formation (osteoinduction) Matrix of the grafting material contains bone inductive substances (osteoinduction), Which would stimulate both the regrowth of alveolar bone and the formation of new attachment.

Schallhorn O.(1967) observed probing depth reduction and bone fill of degree II furcation objects following transplantation of illiac grafts.

Gantes et al (1988): dFDBA

Kenny et al (1988): Porous hydroxyapatite

Pepelassi et al (1991): Composite graft of tricalcium

posphate, plaster of paris and doxycycline

Yukna et al (1994): HTR

Bone replacement grafts alone have had limited

success in managing Class II and III furcation defects.

Problems associated with bone replacement grafts have

included graft containment, epithelial exclusion,

microbial contamination and variable inductivity of the

graft.

Tsao YP (2006) - reported that solvent-preserved,

mineralized human cancellous allograft, with or without collagen

membrane, can significantly improve bone fill in mandibular

Class II furcation defects. In addition, initial vertical defect depth

was found to be the only factor that was associated with a higher

probability of clinical improvement

Akbay (2005) – reported that autogenous PDL grafts has

potential in promoting healing of furcation lesions. This

preliminary study suggests that the use of PDL grafts may have

beneficial effects in the treatment of furcation defects.

GUIDED TISSUE REGENERATION:

Guided Tissue Regeneration is defined as procedure

attempting to regenerate lost periodontal structures through

differential tissue responses.

Barriers - excluding epithelium and gingival corium from

the root surface in the belief that they interface with regeneration.

Using GTR, Gottlow et al (1986) demonstrated clinical and

histological resolution of angular as well as furcation defects in

humans.

These barriers can be

absorbable/non-absorbable

natural/synthetic.

clinical indications - first mandibular molar with a Class II

furcation lesion.

Other furcation lesions in other areas of the mouth have also

been approached with this therapeutic principle, although

rendering different outcomes.

The first generation of GTR studies were carried out using

non-resorbable expanded polytetrafluoroethylene membranes.

Pontoriero et al (1988) clearly demonstrated significant

clinical attachment when this regenerative therapy was used.

Paul et al (1992) and Laurell et al (1994) used resorbable

barrier membranes namely bovine derived collagen membranes

and polylactic acid based membranes respectively, in the

treatment of Class II furcation defects.

resorbable membrane materials - avoidance of a second

surgical intervention and thus the prevention from exposure of the

newly formed tissue underneath the membrane.

GTR procedures in the treatment of furcation defects

demonstrate similar outcomes when different membrane barrier

materials were compared.

The placement of a barrier membrane for GTR in the

treatment of maxillary Class II furcations does not have any

benefit over the standard treatment (open flap debridement).

Pontoriero et al (1995) demonstrated that the location of the

maxillary furcation (buccal, mesial or lingual) does not change

the clinical outcome.

Sanz and Giovannoli (2000) - placement of a barrier membrane should not be indicated in the treatment of maxillary molars with furcation involvement.

Pontoriero et al (1989) observed that the use of ePTFE was less effective in the treatment of mandibular Class III furcations.

Eickholz P et al (2006)- reported horizontal clinical attachment level (CAL-H) gain achieved after GTR therapy in Class II furcations was stable after 10 years in 15 of 18 defects (83%). The study failed to show a statistically significant difference in stability of CAL-H gain between non-resorbable expanded polytetrafluoroethylene barrier (ePTFE; C) and the other a bioabsorbable (polyglactin 910; T)10 years after GTR therapy.

Lekovic et al (2003)- reported that the platelet-rich plasma

(PRP), bovine porous bone mineral (BPBM) and guided tissue

regeneration (GTR) combined technique is an effective modality

of regenerative treatment for mandibular grade II furcation

defects.

Donos N (2003) - reported that the histological evidence

suggest, that both GTR and EMD may result in true periodontal

regeneration, and suggest that this type of healing might be

favored by such treatments in comparison with flap surgery

GTR + BONE GRAFTING

PATIENT FACTORS INFLUENCING SUCCESSFUL REGENERATION

Each patient has a different healing potential that can directly influence the response to treatment.

The patient-related factors - negative influence on the regeneration - smoking, stress, diabetes mellitus, acquired immunodeficiency syndrome and other acute and debilitating diseases, and the presence of multiple deep periodontal pockets.

Age, gender and type of periodontal disease not play a major role in regenerative therapy.

Smoking.

Epidemiological and longitudinal studies have shown an increased prevalence of periodontal disease and progression rate among smokers compared to non-smokers.

associated with a reduced healing response following GTR treatment.

Ah et al. reported that smokers of more than 10 cigarettes a day respond less favorably to both conservative and surgical periodontal therapy than do non-smokers.

Kaldahl et al. noted that heavy smokers (>20 cigarettes per day) respond less favorably than light smokers (<20 cigarettes per day)..

Stress.

not yet been studied.

considered to be a possible risk factor for periodontal breakdown.

The proposed mechanisms for the negative periodontal effects of stress include neglect of oral hygiene, changes in diet, increase in smoking and other pathogenic oral behaviors, bruxism, alterations in gingival circulation, changes in saliva, endocrine imbalances and lowered host resistance.

Diabetes mellitus.

The diabetic's susceptibility to periodontal disease and impaired wound healing can affect response to periodontal therapies such as GTR.

Other systemic conditions.

A negative prognosis - anticipated in HIV-positive patients, rheumatoid arthritis, and other immune-complex diseases.

High doses of irradiation in patients with a history of head and neck tumors might be detrimental to the regenerative process

Presence of multiple deep periodontal pockets.

GTR - with low levels of pathogens in the oral

cavity.

Barrier membranes are at risk of becoming

contaminated within 3 min of intra-oral membrane

manipulation in individuals with multiple deep

periodontal pockets, bleeding on probing in other parts

of the dentition, and high subgingival levels of putative

periodontopathogens.

Research has shown a negative correlation between

bacterial contamination of the membrane and clinical

attachment gain .

LOCAL FACTORS INFLUENCING SUCCESSFUL REGENERATION

Furcal Anatomy

Defect Morphology

Thickness of Gingival Tissue:

Tooth Mobility - clinical relevance of mobility in

regenerative therapy has not yet been elucidated.

Machtei and Schallhorn recommended that very mobile teeth be splinted prior to GTR in class II furcation defects.

Trejo and Weltman recommended the splinting of hypermobile teeth to improve patient comfort during post-therapeutic healing.

However, the clinician must recognize progressing tooth mobility due to trauma, teeth under premature centric occlusal contact, and teeth under traumatic excursional interferences. Such occlusal discrepancies should be removed to minimize trauma and thus tooth mobility prior to regenerative therapy.

SURGICAL FACTORS INFLUENCING SUCCESSFUL REGENERATION

infection control

bone replacement grafts combined with barriers or GTR

alone

type of barrier

surgical technique

space maintenance under the barrier

membrane stability

POSTOPERATIVE FACTORS INFLUENCING

SUCCESSFUL REGENERATION

plaque control

membrane exposure

membrane retrieval

regular supportive periodontal care program

Machtei et al (1995) in his report on the evidence based treatment approach for regeneration, concluded that GTR in combination with or without bone replacement grafts was the treatment of choice for Class II furcation defects.

Combining osseous grafting with GTR enhance the response to membrane only therapy with bone formation via the inductive effects of the graft and supporting the membrane to a more optimal position in selective sites. Similarly the combination may enhance grafting only therapy in selective areas via better containment of the graft and epithelial exclusion.

TOOTH EXTRACTION: Earlier Saxe and Carmen (1969) had stated that the

indications for removal of a tooth with a Grade III furcal defects are:

1) The existence of an unopposed molar which is the terminal tooth in the arch.

2) A first molar with adjacent second premolar and second molar each with adequate bone support.

3) A solitary distal abutment tooth which exhibits mobility.

PROGNOSTIC FACTORS : McGuire and Nunn (1996) reported that the risk of

periodontitis progression in the Furcation lesions increases with the severity of the Furcation involvement

Wang et al (1994) noted that mobile furcated molars are at greater risk for loss of attachment in the furcation area.

Restorations (Wang H.L. et al 1993) and smoking habits (Mullaly et al 1996) have been shown to be positively correlated with the presence of furcation involvement. They may accelerate the rate of disease progression thus increasing the risk for exfoliation of furcated teeth.

Conclusion

One of the most important and at present unsolved problems

in clinical periodontology is the predictable successful treatment of

periodontitis-affected furcations of multirooted teeth. Since

several therapeutic approaches are proposed, i.e., conservative,

resective or regenerative, a proper diagnosis of these lesions is

demanding. The ideal management of the furcation, or for that

matter any periodontal disease, would be preventative & this

consists of controlling plaque and occlusal forces so that the

resistance and reparative capacity of the periodontium is not

exceeded.

Once the furcation area is involved with periodontal

disease, therapy is designed to definitively eliminate the

etiological factors and to establish a morphology at the

dento-gingival region, which facilitates proper tooth

cleaning by the patient. As to the mode of therapy, the

clinician must decide on the therapeutic approach, based

upon the needs & requirements of each patient on an

individual basis.

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