INTER-RADICULAR LESIONS Therapeutics
I-Introduction:
The furcation zone of multirooted teeth is a unique region in the periodontal structures, presenting specific characteristics and particular clinical and therapeutic challenges. When periodontitis sets in, affected teeth are characterized by deep pocket formation and a periodontal destruction process that is accompanied by both vertical and interradicular attachment and bone loss. Deep pockets in molars are frequently associated with a combination of horizontal interradicular involvement, craters, and intrabony defects on one or more roots.
Diagnosis of interradicular lesion is quite difficult. The use of clinical and radiographic tools to assess horizontal involvement is essential for diagnosis, prognosis and treatment planning of compromised molar.
II-Definitions:
1- The furcation zone (the cervical trunk) : according to EASLEY DRENNAM
This is the area delimited at its upper part by the enamel-cement junction, in its lower part by the point of divergence and separation of the roots; the surface of this area varies according to the coronal and radicular morphology. We can speak of bifurcation (two roots like the mandibular molars and the first upper premolars) or trifurcation (3 roots like the upper molars).
2-The inter-radicular zone or region:
It is delimited at its upper part by the most inclined furcation zone and laterally by the root walls
3- The inter-radicular lesion:
It is a loss of substance located between the roots of multi-radicular teeth, with bone lysis in the coronoapical direction, and in the vestibulo-lingual direction of the inter-radicular septum.
III-Etiological factors:
1-The main triggering factor:
Bacterial biofilm is the main factor in periodontal lesions leading in some cases to the formation of a periodontal pocket and bone lysis.
2-Predisposing factors:
2-1-Anatomical and histological factors
- Distance from the furcation to the enamel-cement junction line: The higher the furcation is in the coronal direction, the greater the chances of invasion of this furcation will be in the context of generalized periodontitis;
- Root shape and location: Implantation of the tooth between the bony tables can create risk areas where bacterial or traumatic inflammation will promote loss of attachment; the furcations of the first mandibular molars are very close to the external bony tables (root proximities)
- The periodontal ligament in this area is loose
- Enamel projection: The connective fibers cannot anchor themselves in the enamel surface, resulting in epithelial adhesion with a more or less long junctional epithelium
- Enamel beads.
INTER-RADICULAR LESIONS Therapeutics
2-2- defective restorations.
3-Other Factors:
- Endodontic pathology: any endodontic pathology that can open through the lateral or accessory canals, because the diameter of these canals is greater than the diameter of the bacterial germs.
- Perforation of the pulp floor
- Presence of extensive caries;
- Poorly conducted extraction of maxillary wisdom teeth exposing the disto-palatal furcation of the second molars.
- Presence of occlusal trauma.
IV – Diagnostic methods:
1-Clinical examination:
In addition to a detailed clinical examination; exploration of the furcations is carried out using a curved probe with a blunt tip (NABERS type).
– For the lower molars, the approach is vestibular and lingual.
– Concerning the upper molars, the examination is vestibular, mesial and distal.
Examination of the mesial and distal divisions is preferably done through palatal access.
2-Radiological examination :
An X-ray examination will give us essential additional information.
– The loss of bone substance forms a radiolucent zone of variable size.
– Early bone lesions may not be seen, but in most cases the radiographic image provides evidence. In fact, it is the only tool to reliably determine the height of the alveolar bone crest.
– It also allows us to know the number and shape of the roots, their degree of separation and divergence
– Cone beam or cone beam computed tomography (CBCT) examination allows bone damage to be visualized under different sections and with a 3D reconstruction.
IV-Classifications of interradicular lesions
1-Glickman classification :
Class I: initial lesion
Supra-bony pocket, reaching the soft tissue; there is slight bone loss at the furcation area. Visible change on X-ray is rare, as bone loss is minimal
Class II: partial injury
Bone is destroyed at one or more surfaces of the furcation, but some periodontal tissue remains intact, allowing only partial penetration of the probe.
Class III: total injury
The furcation may be obstructed by the gingiva but the bone has been destroyed to a significant degree to allow full passage of a probe in a vetibulolingual direction. Radiography reveals marked bone lysis.
Class IV: pronounced total lesion
Like the 3rd stage, the interradicular bone is completely destroyed, but with denudation making the furcation opening visible.
2-Hamp, Nyman & Lindhe classification (1975):
Initial lesion: horizontal destruction of periodontal tissues not exceeding 1/3 of the width of the tooth;
Partial lesion: horizontal destruction of periodontal tissues exceeding 1/3 of the width of the tooth, but without reaching the entire width of the interradicular space;
Total lesion: horizontal destruction throughout the periodontal tissues at the level of the interradicular space.
3- Tarnow and Fletcher classification (1984)
Completed the horizontal classification of HAMP in the vertical direction by adding the vertical measurement of attachment loss with subclass lesions (A, B, C)
Sub Class A: vertical bone defect 1 to 3mm
Sub Class B: vertical bone defect 4 to 6mm
Sub Class C: vertical bone defect > 7m
4-Meyer classification:
He considers the inter-radicular lesion in relation to the adjacent bone context. He adds to this millimeter penetration of the probe a radiological assessment of the adjacent bone, assimilating an inter-radicular lesion to an interdental bone lesion.
Interradicular supraosseous lesion: interradicular bone level is located coronal to the proximal bone.
Juxta-osseous inter-radicular lesion: inter-radicular bone level is located at the same level as the proximal bone.
Infraosseous interradicular lesion: interradicular bone level is located apically to the proximal bone.
5-The Universal Classification:
The extent of furcation damage is expressed in 3 degrees depending on the extent of horizontal tissue destruction within the inter-radicular space.
Class I: horizontal attachment loss up to 3mm
Class II: horizontal attachment loss greater than 3mm
Class III: total loss of horizontal attachment allowing the probe to pass through
V- The therapeutic approach to inter-radicular lesions:
1-Objectives of the processing:
– Perform correct debridement by accessing the root surfaces following an intervention under visual control
– elimination of pockets;
– Establishment, at the level of the dento-gingival region, of a morphology which facilitates the correct performance of hygiene care by the patient.
2-The criteria for choosing the treatment plan:
- According to class (universal classification)
- Survey of pockets of the sector concerned
- Character of lysis at the proximal and inter-radicular levels
- Root anatomy: height of the root trunk, width of the interradicular space
3- The different therapies: according to the universal classification
3-1- Class I:
– Scaling with root planing
-Periodontal curettage: to eliminate suprabony pockets.
-Gingivectomy/gingivoplasty: Can make it possible to eliminate the periodontal pocket and facilitate plaque control by the patient.
– Odontoplasty:
Which consists of a remodeling by rotary instrument of the root with the aim of widening the entrance of a furcation or eliminating an overhanging crown allowing better hygiene and good plaque control.
INTER-RADICULAR LESIONS Therapeutics
Operating protocol
- Mucoperiosteal flap is reclined
- Removal of soft and hard bacterial deposits as well as inflammatory tissue located at the furcation level
- Coronoplasty, i.e. removal of dental substance at the furcation area in order to widen the inter-radicular invagination at the root base and reduce the horizontal depth of the lesion. Care must be taken not to remove too much dental substance during odontoplasty because in the event of excess the risk of increasing root sensitivity will increase.
– Flap operation: apically displaced flap, modified WIDMAN flap
3-1- Class II:
– Debridement treatment as for class 1
– Odontoplasty
– Osteoplasty ; If the furcation tunnel diameter is narrow or access to the furcation is restricted, osteoplasty may be necessary, so the alveolar bone of the interradicular region is then remodeled to give a deflecting gingivo-osseous architecture improving oral hygiene by the patient
– Tunneling :
This technique consists of opening and enlarging the interradicular space; that is to say, transforming a class 2 into a class 3 allowing the passage of an interdental brush.
This technique is mainly recommended for mandibular molars, when the roots are divergent with a wide interradicular bony septum.
After flap detachment and DSR and removal of granulation tissue, the interradicular region is widened by removing part of the interradicular bone to allow the passage of a brush for the maintenance of hygiene by the patient.
The alveolar ridge is remodeled and some of the interdental bone mesial and distal to the tooth is removed to achieve a flat contour of bone at the level of the tooth in question.
During maintenance exposed surfaces should be treated with topical applications of Chlorhexidine and fluoride varnishes, as there is a marked risk of root sensitivity and development of carious lesions on roots exposed at the level of artificially created tunnels.
– Flap operation : Modified Widman flap, apically displaced flap.
– Regenerative techniques:
*Bone grafts with or without membrane: autograft
*Guided tissue regeneration
*The use of enamel matrix proteins in cases of grade II disease on mandibular molars also significantly improves clinical outcomes.
3-2-Class III treatment:
– Scaling with root planing
– Odontoplasty
– Osteoplasty
– Tunneling
– Root amputation:
- Definition :
Root amputation consists of removing a root from a multi-rooted tooth without affecting the coronal part of the tooth.
- Indications:
- Bone loss affecting one or more roots that cannot be treated by regeneration
- Severe gingival recession (presence of bone dehiscence) Recurrent endo-periodontal infections
- Deep caries in the root or in the inter-root space
- Contraindications
- General
- Apex Fusions
- Furcation too apical
- Interradicular lesions of maxillary premolars
- Fused roots
- Unable to restore preserved roots
- Absence of occlusofunctional role
- Operating protocol:
1. Endodontic treatment
2. Surgical therapy
- A mucoperiosteal flap is reclined
- Using the contra-angle + fissure bur, cut the root at its source and extract it.
- Perform coronal remodeling to allow easy passage of instruments
- Perform osteoplasty
- Scaling and planing of root surfaces, cleaning of the area, repositioning of the flap and placement of a surgical dressing.
3. Functional restoration:
These teeth can remain in place for a long time or be included in fixed reconstructions. The occlusion must be particularly well adjusted.
– Hemisection:
- Definition
Consists of performing a total coronal section of a tooth in order to create coronal-radicular stumps.
– Extraction
When attachment loss is so extensive that no roots can be maintained or treatment will not result in anatomy that permits hygiene control, tooth extraction should be considered.
Good oral hygiene is essential to prevent cavities and gum disease.
Regular scaling at the dentist helps remove plaque and maintain a healthy mouth.
Dental implant placement is a long-term solution to replace a missing tooth.
Dental X-rays help diagnose problems that are invisible to the naked eye, such as tooth decay.
The dentist uses local anesthesia to minimize pain during dental treatment.