Salvaging Periodontally Compromised Multi Rooted Teeth - Review and A Case Report.

INTRODUCTION

“Saving part of a tooth is better than removing it”

- FARRAR

“If three roots are better than two,

then two roots are better than one,

and one root is better than none”.

Inflammatory periodontal disease if left untreated results in attachment loss sufficient enough to affect the bifurcation and trifurcation of multirooted teeth. It is impossible to debride the furcation area by routine periodontal instrumentation and also routine home care methods cannot keep the furcation area free of plaque which may lead to further destruction and ultimately loss of tooth.

The objective of furcation treatment is to facilitate maintenance, prevent further attachment loss, obliterate furcation defect so that maintenance is possible. This involves a multi-disciplinary approach depending upon the type and severity of the defect. Hence the aim of this article is to describe the various periodontal and restorative treatment options available to salvage periodontally compromised molar teeth. This paper also reports one such procedure followed in a case which is explained in detail and few other similar cases restored by various restorative options.

CLASSIFICATION OF FURCATION:¹

Glickman (1958): gave the Horizontal classification, based on the horizontal loss of interdental bone:

• Grade I: Incipient Involvement into the flute of furcation with suprabony pockets and no inter-radicular bone loss.
• Grade II: Involvement extends under the roof of the furcation but not through and through.
• Grade III: A though and through loss of inter-radicular bone.
• Grade IV: A through and through loss of inter-radicular bone with total exposure of the furcation due to gingival recession.

A subclassification is necessary to permit a more accurate description and is an important indicator of prognosis.

Lindhe (1983): proposed antoher Horizontal classification:

• Grade I: Vertical destruction upto one third of the total interradicular height (1-3mm).
• Grade II: Vertical destruction reaching two-thirds of the interradicular height
• Grade III: Interradicular osseous destruction into or beyond the apical third (>7mm)

Tarnow and Fletcher (1984): proposed a Vertical classification based on vertical loss of interdental bone:

• Grade A : Vertical loss of 1 to 3mm.
• Grade B : Vertical loss of 4 to 6mm
• Grade C : Vertical loss of 7 or more mm.

Treatment methods are chosen to match the degree of involvement. Roentgenograms are necessary to gauge the degree of bone loss. Periodontal probes are useful for determining the probing depth in a vertical direction (pocket depth) but are less useful for determining the degree of horizontal involvement.

TREATMENT OPTIONS:¹

The major principle of treatment of involved furca is to eliminate the involvement. But not all the variety of methods available provide for elimination of the furcation. Some provide only for plaque removal; some reduce the susceptibility of the tooth to caries.

The treatment methods may include minimal preparations like odontoplasty or osteoplasty in the initial grades of involvement. In advanced grades of furcation involvement extensive procedures like root amputation, hemiseciton ,root separation, tunneling can be carried out to retain the tooth while extraction may be required when the above procedures are not feasible due to some contraindications.

Factors to be considered when deciding on a mode of therapy:

1. Degree of involvement

2. Crown root ratio

3. Length of root separation

4. Strategic value of the tooth or teeth in question

5. Root anatomy of the involved tooth.

6. Residual tooth mobility

7. Ability to eliminate the defect.

8. Endodontic therapy and complications.

9. Prosthetic requirements

10.Periodontal conditions of adjacent teeth

Management of degree I and mild degree II involvements:

Initial Preparation: Scaling and proper oral hygiene are the first treatment procedures.

Odontoplasty: is defined as the reshaping of a tooth. It can eliminate class I and mild class II furcation involvements. The fluted area of the tooth is reshaped by extending toward the occlusal surface. Odontoplasty should be used insidiously else will contribute to increased sensitivity.

Osteoplasty: Osteoplasty may be used with class I and class II involvements to tuck the gingival into the furcation to provide better gingival form as well as to eliminate sulcular depth. This procedure may be combined with odontoplasty.

Management of degree II and III furcation involvements:

Moderate and severe furcating involvements require additional methods of treatment when the desease process is not controlled by initial preparation. Such additional treatment methods include root amputation, tooth sectioning/ hemisection, root separation and tunnelling.

Root amputation²

Root amputation is the removal of one or more roots from a multirooted tooth. The primary benefit gained from root amputation is improved access.

Indications for root amputation:³

1. Severe and disproportionate attachment loss around the affected root.

2. Furcation defects that can be eliminated by root amputation.

3. Improved prognosis for adjacent teeth.

4. Retention of a tooth with strategic value.

5. Elimination of an endodontically untreatable root.

6. Elimination of cracked or deeply fissured roots.

7. Pockets in areas of root proximity of adjacent multi rooted teeth.

8. Recession exposing most or all of a root in a multi rooted tooth.

9. Inoperable root caries.

Contraindication of root resection:³

1. Fused roots (along their length or at their apices).

2. Roots in acutely close proximity.

3. Inability to utilize treated tooth in an approximate restoration.

4. Inability to treat tooth endodontically.

5. If patient is not co-operative.

Timing of Endodontic Treatment:⁴

Ideally, endodontic therapy should precede amputation. Sometimes the initial periodontal endodontic lesion will heal, precluding the need for root amputation. Where an amputation is planned, amalgam may be placed in the canal of the root to be amputated to permit contouring. When the therapist is uncertain as to which root will be amputated, or when a combined periodontal - endodontic lesion is suspected, all canals should be filled.

Factors determining selection for root amputation include:

I. Bone levels in the furcation

ii. Accessibility for plaque removal

iii. Root proximity

iv. Position of the root in the arch

v. Root morphology vi. Endodontic complications

Root Selection:⁵

Normally, the root with the greatest bone loss should be considered for amputation. In maxillary molars, removal of any root will improve access to the furcation. E.g.: Removal of a mesiobuccal root, provide access for removal of plaque on remaining roots.

In mandibular molars, hemisection eliminates the furcation. In either case the prognosis of the remaining roots is improved. Root amputation is facilitated by divergent roots. When roots do not diverge or are partially fused, amputation is complicated or impossible, when distobuccal root of the maxillary first molar contacts or is close to the mesiobuccal root of the second molar, removal of the distobuccal root is preferred. Access to both teeth and their prognosis are improved. The buccal roots of maxillary molars are more centrally located in the arch, in line with the premolars, and therefore are more readily crowned and used as abutments than the palatal root. Removal of a buccal root makes maintenance of a furcation more difficult.

Root surface area should be considered before a root is amputated. In maxillary molars distobuccal roots provide the least support and should be considered preferentially for amputation over the palatal and mesiobuccal roots, which provide approximately equal support. When removal of a palatal or mesiobuccal root is considered, the arch postion favours the retention of the mesiobuccal root, however access for plaque control is complicated by a distal concavity. Access to this area (proximal surface of molars) is improved by palatal root amputation.

Mandibular molar roots are approximately the same size, although the mesial root is slightly larger. However, the concavities on the mesial root are less accessible for plaque removal. The two narrow gulp canals of the mesial root are more difficult to treat endodontically than the single, larger canal on the distal root. Post and core restorations are more easily constructed on the distal root.

Root perforation, cracked roots, and non-negotiable canals are indications for amputation.

The positive treatment outcome at the root resected ,furcation involved teeth as well as at the non-furcation involved teeth is probably the consequence of the reestablishment of a tissue morphology favourable for oral hygiene and careful plaque control by the patients. 

Procedure:¹ After the flap is elevated and soft tissue is debrided, amputation of the root is accomplished with a tapered carbide or diamond bur in a high speed hand piece. The cut is designed to contour the root trunk and crown while separating the root from the tooth. The initial cut is mode at the expense of the root being amputated. The root is carefully elevated and removed without placing pressure on the remaining tooth. The root trunk is then shaped to ideal contour, this includes removal of spurs and contouring of the root trunk to eliminate inaccessible portion of the furcation. If a palatal root is amputated the buccolingual width of the crown should be narrowed from the lingual surface of the approximate width of a premolar.

Remaining roots should be planed and osteoplasty completed to enhance pocket elimination and flap closure. Sutures are used to maintain flap adaptation and a dressing is placed as desired. Where needed, a restoration is placed to seal the exposed root canal.

Vital Root Amputation:

Vital root amputation may be performed with the intention of maintaining pulp vitality or with the intention of completing endodontic therapy subsequently. Vital amputation may be done when removal of a root has not been planned but is considered necessary during periodontal surgery. Unexpected patterns of bone loss, root fracture, root caries, external resorption, and root anomalies may require vital root amputation during periodontal surgery. There is little or no pain for about a month after surgery. Capping of the exposed pulp stump is not necessary if a root canal filling will be placed post operatively. The patient may experience discomfort to hot or cold stimuli, and pulp polyps may develop in the area of exposure. The primary disadvantage is the increased difficulty in gaining profound anesthesia for subsequent pulp extirpation.

Long-term maintenance of pulp vitality requires pulp capping at the time of root amputation. A small preparation is made in the exposed root canal with an inverted cone bur. The pulp is capped with calcium hydroxide followed by an amalgam restoration. A success rate of 70% over 5 years has been reported.

However, endodontic therapy before or immediately after root amputation remains the present treatment of choice .

Tooth sectioning/ hemisection.³

Sectioning is the surgical sectioning of a tooth into segments consisting of the root and overlying crown. An individual section may be extracted or retained. Hemisectioning generally applies to mandibular molars but may be performed on any multi- rooted tooth endodontic treatment is completed before sectioning is attempted. Hemisection is contraindicated in teeth where:

1. The remaining periodontal support is inadequate

2. The tooth cannot be treated endodontically

3. Adequate restoration of the remaining tooth including splinting cannot be performed Hemisection technique

After endodontic therapy is completed the pulp chamber can be filled with amalgam. When possible, hemisection can be completed without flap elevation. A flap is required when visibility is limited, bone loss is irregular, and osseous defects require access for treatment. A flap is elevated and granulation tissue removed to provide access for sectioning. The sectioning is done with a carbide bur or tapered diamond. The involved root is carefully extracted. The retained root is contoured to remove remnants of the furcation roof and to obtain a smooth, even contour. Minimal osteoplasty may be performed to enhance flap closure. Sutures and dressing are placed. Mobility may be increased after the operation. The occlusion should be relieved to reduce trauma. The tooth should become firm within 6 months. If the tooth doesn't become firm, splinting is necessary.

Root Separation³

Root separation is the process of dividing a mandibular molar into two separate teeth (bicuspidization). The rationale is that by separation of the roots, plaque control is enhanced, and the part of the tooth most susceptible to caries is changed from a dentin or cementum surface to a metallic one. The tooth fragments may be joined by one metallic restoration or converted into two separate teeth by the construction of two crowns. The procedure is indicated when there is a class III involvement, the tooth is a strategic tooth, and the roots are well supported and sufficiently separated from each other to allow construction of restorations. The procedure may be combined with osteoplasty to correct defective bone contour margins without overhangs, and creation of a new contact point or solder joints that permit adequate inter-radicular cleaning. Teeth with deep furcation defects and unaffected mesial and distal surfaces are poor candidates for sectioning.

Tunnelling:¹

Tunneling is a more rarely used procedure available for treatment of teeth with class II or III furcation involvement. The furcation is opened more widely to improve access for plaque control by proximal brushes, yarn, or pipe cleaners. Topical application of fluoride solutions may assist in caries control. Tunneling is generally limited to mandibular molars but may be combined with root amputation in maxillary molars. Odontoplasty can be used to raise the roof of the furcation for increased access for plaque removal. Tunneling should not be used in caries-prone individuals.

Prosthetic options⁶

Teeth with a resected root may be restored in a variety of ways. They may be involved in a treatment plan as single units, as fixed or removable partial denture abutments, or as vertical stops for an overdenture.

The most common types of restorations for teeth with resected roots involve retaining the remaining root restoring it as an individual tooth.(figure 4) and using the same as an abutment for a fixed or removable partial denture(figures 6& 7). Premolarisation involves restoring the individual roots of a molar with premolar occlusal morphology(figure 4) . A minimum treatment plan includes placement of amalgam in the root(s) and adjustment of occlusion. The segment retained following a hemisection can also be used as an overdenture abutment. (figure 8).⁷ The two segments may be restored either as individual crowns with occlusal morphology similar to premolars or as separate crowns rejoined occlusally with a molar occlusal morphology and a concave connector from one root to the other. In either case the contact area is maintained in occlusal one third making it accessible for proper oral hygiene maintenance(figure 5). Thus protecting  the caries prone area.⁸ The occlusal forces are controlled by minimizing the cuspal inclines on the resected molar crowns.⁹

A CASE REPORT

A 18 year old male patient reported to the clinic with pain on chewing from left side lower back tooth of the mouth. On intra oral examination, a large silver amalgam restoration was present in 36. IOPA radiograph of 36 revealed a frank involvement of the furcation roof (figure 1). First molar being a strategic tooth and considering the age of the patient we planned to save the tooth rather than extraction. The treatment plan involved hemisection and restoration of the mesial and distal segments with separate crowns. Therefore root canal treatment followed by post endodontic restoration with silver amalgam was conventionally carried out. A full thickness flap was raised under local anesthesia. A notch was placed on the crest of buccal cortical plate(figure 2). The sectioning was carried out beginning from buccal groove towards lingual dividing the tooth into halves. Enamel lip at the furcation is removed using a round end tapered bur. The flap is closed and sutures placed (figure 3). Tooth preparation is completed to receive premolarised crowns. An acrylic resin provisional restoration is provided to stabilize the tooth 6 segments against masticatory forces. The two segments of the sectioned molar were restored with premolarized crowns with contact area shifted to the occlusal one third allowing space for cleaning with an interdental brush (figure 4). Patient was recalled at regular intervals for evaluation.

CONCLUSION

With the knowledge of such things as normal radicular and periodontal anatomy, the disease process, and its effect on tissues, sequence of therapy, endodontic considerations, periodontal therapy and restorative principles, all create an interdisciplinary therapeutic network with tremendous overlapping of responsibilities. Preservation is always better than replacement.