Endodontic surgery

Endodontic surgery

1. Introduction :

Endodontic surgery is a discipline that is inseparable from a good knowledge of the practice of orthograde endodontics. Indeed, a certain number of clinical situations

require the use of the latter the establishment of the indication of the surgical act and the

Compliance with the surgical protocol determines the success and progress towards healing of the initial lesions.

2. Definitions:

Endodontic surgery cannot be described as oral surgery in the traditional sense of the term; rather, it is defined as a genuine “endodontic treatment by reflection of a surgical flap”.

• Apical surgery can be defined as access to the apex by surgical means for therapeutic purposes.

3. Purpose of endodontic surgery:

The aim of endodontic surgery is to seal the endodontium, at any accessible level of the root of a tooth, and to complete it, if necessary, by curettage of the

periapex and/or a lateroradicular area, in order to rid them of a foreign body, an apex fragment, granular or cystic tissue.

4. Indications and contraindications for endodontic surgery:
5. Indications:

Endodontic surgery is mainly indicated in cases:

• persistence of symptoms (exploratory surgery)
• radiological failure of adequate orthograde treatment
• iatrogenic perforation – fractured instruments not accessible by conventional means
• iatrogenic excess with persistence of symptoms
• of waterproof channels with LIPOE b- Contraindications :

1. Local contraindications:

They are linked to the intrinsic value of the tooth. The unfavorable criteria are:

• a total coronary collapse
• poor condition of the periodontium
• insufficient length of the residual root
• a high vertical and horizontal fracture

2. Regional contraindications:

The essential conditions being accessibility and visibility, any event which could hinder these two imperatives is a contraindication. This includes:

• at the skin level: scar…;
• at the muscular level: excessive tone of the orbicularis muscles, microstomia
• at the pathological level: chronic cheilitis, scleroderma;
• at the bone level: significant thickness of the cortices (bony palate, external oblique line);
• at the oral level: limited mouth opening range, unfavorable for root access.

3. General contraindications:

• For patients falling into the category of strict medical contraindications
  • patient at risk of category A infective endocarditis,
  • patient who has undergone cervicofacial irradiation,
  • patient taking bisphosphonates,
  • malignant hypertension)

Surgery is strictly contraindicated, as it risks endangering their general health.

• For medical contraindications Relative: In practice the risk will be assessed by the dentist during the consultation and in agreement with the doctors concerned. Most of the time surgery can be performed on these patients with specific precautions for each situation (antibiotic prophylaxis)

5. periapical surgery:

Operating protocol:

1. Anesthesia:

The anesthesia has only one particularity, it is periapical and subperiosteal in order to facilitate the next step: the detachment of the full-thickness flap:

• the anesthetic solution contains a vasoconstrictor (adrenaline 1/100,000);
• the cartridge is warmed before use
• the injection is slow
• infiltration is tracer for significant lesions

2. The incision:

The rules to follow are:

• the type of incision is chosen according to:
  • of the seat and the nature of the intervention
  • the condition of the fibromucosa (thickness, keratinization)
  • of the state of the periodontium
  • suture possibilities
• the scalpel is oriented perpendicularly, or slightly obliquely in relation to the bone table; it always maintains bone contact
• it is necessary to avoid returning to an incision
• the incision should preferably be made in the keratinized gingiva
• you must follow a path in a depression (between two roots) and not on a bony eminence (root relief, fenestration)
• the incision must be able to be modified during the operation

3. Incision outline:

Triangular incision:

The outline is made up of two lines

• a horizontal incision, which can be intra- or extrasulcular
• a vertical discharge incision, between the reliefs of two acinars, and respecting the papilla.

The specific features of the intrasulcular incision are as follows:

• it allows to correct a slight gum recession
• it allows to regularize an alveolar crestal contour
• it allows the initiation of guided tissue regeneration (GTR).

The special features of the extrasulcular incision Luebke-Oshenbein flap are:

• it respects the possible prosthetic cervical limits, when they are correct

; when the embrasures are insufficient between the single prosthetic teeth.

• This type of incision is delicate and requires a careful periodontal examination in order to

to assess the depth of the sulcus and the presence of pockets, revealing pathological dehiscences

• The horizontal incision is located at least 1 mm from the sulcus, in the gum

keratinized and is scalloped, that is to say that it follows a path parallel to the gingival contour at the

4. Flap detachment:

All detachers used in surgery are suitable

5. Flap management

The flap is loaded onto a retractor. There are many different types, varying in shape and size. It all depends on the size of the flap to be held. All of these retractors are derived from the Farabeuf retractor, and are more or less miniaturized.

6. Transosseous trepanation:

This is the most delicate step in terms of saving tissue and the risk of target error.

1. Where to trepan?

• Regarding pathological markers:
• when the lesion has started the perforation of the bone table, internal or external, the

This often makes it easier to spot this lesion; the lesion thins the cortex, which takes on a dark color.

• Regarding anatomical landmarks:
• the cortex can reveal the relief of the root, a report of the length of the root concerned on the bone determines the apex
• when the bone cortex is intact

This situation obviously makes the approach more difficult.

The X-ray allows the length of the tooth to be estimated and allows the following to be estimated:

• the position of the apices;
• the level of resection of the apices required.
• Trephination can be performed using a round perforating burr, the size of which depends on the extent of the lesion, under irrigation with physiological saline and simultaneous suction. A surgical Zeckreya burr, with an active tip, mounted on a turbine can also be used.

A series of surgical burs can be used: The three burs mainly used are:

• the ball bur, mounted on a handpiece (surgical bur diameter 06 or 08, in tungsten carbide)
• the 1171 bur mounted on a surgical handpiece
• the L 151 and L 151-L burrs which allow both osteotomy and apical resection.

7. Curettage of the lesion:

There are many types of curettes, varying in shape and size. It is best to use flat curettes rather than hollow curettes (Hemingway).

Gracey curettes and dental excavators, which come in different shapes and sizes, allow access to difficult areas.

8. Apex section: apical resection

• The apex can either be sectioned to the desired height using a Zeckrya bur, or reduced from the apex to the intended level using the Zeckrya bur or a round bur of appropriate diameter.
• Always under simultaneous irrigation and suction.
• The section plane, for biomechanical reasons, is as perpendicular as possible to the axis of the root

1. Inspection of the bone cavity:

• Absence of apex: allows you to check the following elements:

• the absence of residual pathological tissue;
• the absence of debris (mineral, metallic, organic)
• the presence of one or more foramina
• the presence of an isthmus
• helps control bleeding

9. Apical filling cavity:

The shape of the apical cavity depends on the material inserted, the accessibility to the apex, the technical possibility of creating this cavity and of filling it.

1. Materials needed:

inserts, of various shapes, diameters and lengths to cope with a large number of situations. Their surface condition can be smooth, rough or covered with diamond particles

2. Method :

The foramina, the straight or curved isthmuses (C-shaped canal) are approached using three movements

:

• an axial movement, along the canal over 3-4 mm, resting on its walls
• a back and forth movement in the case of isthmuses
• a circular movement.

These three movements make it possible to obtain a cavity homothetic to the initial cavity (round, figure 8-shaped, oval, rectilinear or curved)

3. Highlighting the canal system:

After resecting the apical portion of the tooth, the root canal system is exposed. The surface of the resection is examined under an operating microscope using a 17 probe and a micro mirror.

10. Hemostasis:
    1. By chemical processes:

• tamponade of the bone cavity using a vasoconstrictor (1/100,000 adrenaline anesthetic).
• Using a solution containing ferric sulfate which ensures better hemostasis, but requires cleaning of the bone cavity

2. By mechanical processes, such as:

• the compress soaked in vasoconstrictor left in situ,
• cellulose with or without fibrin,
• surgical wax (Bone Wax®),
• Coalgan® composed of calcium alginate.

11. Filling material:

The placement of a filling material is a crucial step in endodontic surgery. It is essential to place a physical barrier to prevent the passage of bacteria and their endotoxins to the periapex.

IRM® (De Trey), Super-EBA® (Bothworth) and MTA (ProRoot MTA®, Dentsply Maillefer; MTA Angelus®, Angelus) which seem to better meet the requirements of modern endodontic surgery.

1. IRM® and Super-EBA®:

• IRM® is composed of a powder (zinc oxide + 2% polymethacrylate and hydroxyapatite) and a liquid (eugenol and acetic acid).
• Super-EBA® is also a mixture of a powder (zinc oxide reinforced with aluminum oxide and natural resins) and a liquid (eugenol and ethoxybenzoic acid).

2. MTA:

MTA (ProRoot MTA® and MTA Angelus®) is a powder whose reported composition is close to that of Portland cement.

• It is made up of fine hydrophilic particles of mineral oxides and bismuth oxide to improve its radiopacity.
• The main components are tricalcium silicates, tricalcium aluminates, tricalcium oxides and silicate oxides.

3. Placing the filling:
   1. For the MTA:

the implementation is more delicate and the protocol differs from the preparation of the material:

• when mixing, the liquid/powder proportions must be precise;
• the grinding time should be longer, 2-3 minutes
• the mixture obtained lacks consistency, it takes on the appearance of sugar or wet sand;
• the curing time is very long;
  • the product is placed in the cavity using the missing gun, which acts like an amalgam holder
  • the MTA is then trampled and then surfaced using a cotton ball moistened with physiological serum
• Cleaning the bone cavity is delicate and must be thorough because the material, which hardens over several hours, can easily be removed during grooming.

2. Root Repair Material(RRM)Putty:

• RRM Putty used in endodontic surgery since 2007, consists mainly of calcium silicate, calcium phosphate and zirconium oxide
• Hydroxyapatite, a product of the setting reaction, forms chemical bonds with the dentin ensuring the elimination of any residual space between the cement and the dentin walls .
• Hydration of the material upon penetration of hydrophilic nanoparticles to

the interior of the dentin tubules allows an expansion of the order of 0.2%, resulting in a watertight seal .

• This type of material has revolutionized apical surgery due to its highly hydrophilic character which allows it to adhere to root walls.
• In addition, fillings over several millimeters are now possible since the setting time is widely compatible, starting after 10 minutes and ending after 24 hours.
• These materials are marketed in pre-mixed form in a high viscosity paste version, which makes them easier to handle than MTA.

3. For MRI and EBA
   • the material is prepared by mixing the powder and the liquid so as to obtain a paste of firm consistency
   • a small portion of the dough is shaped into a cone 2-3 mm high;
   • the cone is placed on a mouth spatula, base against the spatula
   • the cone is introduced, by the tip, into the apical cavity then applied with the spatula
   • the material thus inserted is compacted using a micro rammer once hardened, after 1-2 minutes, it is smoothed with a burnisher
   • the section plane of the apex is surfaced using a Zekrya milling cutter, rotating at low speed, in order to obtain surface continuity
4. Cleaning the bone cavity:

the bone cavity is cleaned, swabbed using a compress soaked in Betadine®

• non-bleeding bone walls should be stimulated before suturing;

13. Suture:

By separate points

14. X-ray control:

It allows you to check the quality of the obturation

15. Post-operative care:

Post-operative care includes:

• broad-spectrum antibiotic therapy based on the patient’s medical profile
• an anti-inflammatory treatment , based on non-steroidal anti-inflammatory drugs (NSAIDs) whose dosage and indication always vary according to the patient’s medical profile. Analgesics are not necessary, NSAIDs at the prescribed dose are analgesic.
• However, in case of persistent pain, paracetamol can be prescribed up to 1 to 3 g/day.
• Mouthwashes are prescribed, as well as a surgical-type toothbrush.
• Suture removal can be performed between the 8th and 10th day after surgery. It is best not to remove sutures too late.
• Follow-up visits are scheduled and carried out at 1 month, 3 months, 6 months and 1 year in order to check the patient’s progress towards recovery.

6. Healing process:

• During the procedure, both soft and hard tissues are manipulated
• Soft tissues (periosteum, gingiva, periodontal ligament, and alveolar mucosa)
• Hard tissues (dentin, cementum, and bone)

a)  Soft tissue healing: encompasses several mechanisms

• Blood clotting: The clotting mechanism is important because it is based on the conversion of fibrinogen into fibrin. Under certain pressure, the clot appears as a thin layer.
• inflammation
• Connective tissue healing, along with maturation and remodeling, consists of forming a barrier made up of layers of epithelial cells.
• This layer migrates along the entire fibrin surface until it comes into contact with the epithelial cells at the opposite edge of the wound, thus forming an epithelial bridge
• Connective tissue components originate from fibroblasts that result from the differentiation of ectomesenchymal cells and are attracted to the wound site
• Adjacent blood vessels provide nutrients to fibroblasts and their precursors to manufacture initially type III collagen, followed by type 1 collagen

b) Healing of hard tissues:

• The hard tissue response is based on the presence of cells such as fibroblasts, osteoblasts and cementoblasts which produce the ground substance and contribute to the formation of the bone matrix
• The deposition of neocement by cementoblasts begins 12 days after surgery.
• Exposed dentin acts as an inductive force for cementum formation from the periphery to the center
• Bone healing begins with the proliferation of endosteal cells within the coagulum of the wound site
• After 12 to 14 days , the trabecular meshwork and osteocytes appear, leading to early maturation of the collagen matrix at around 30 days.
• This process occurs from the inside out and ends with the formation of mature lamellar bone, which is visible radiologically

7. Healing in endodontic surgery:

Healing, let us remember, is the return to normal of the function of the tooth, clinical silence and radiographic image showing the reconstruction of the four structures (cementum, desmodont, lamina dura, and bone), even if these images, as some authors believe, do not reflect a histological reality

Three categories now make it possible to define the criteria for success based on radiographic and clinical analysis:

• healing , i.e. absence of clinical signs and disappearance of the lesion on the X-ray;
• healing , i.e. absence of clinical signs accompanied by a reduction in the size of the lesion;
• failure , either persistence of the lesion or clinical signs

• After 12 to 14 days , the trabecular meshwork and osteocytes appear, leading to early maturation of the collagen matrix at around 30 days.
• This process occurs from the inside out and ends with the formation of mature lamellar bone, which is visible radiologically

8. Corrective surgery:

Designed to correct pathological or iatrogenic situations

• Directions:

1. root perforation (when preparing the access cavity, a canal, or preparing a root canal
2. Perforations following resorption
3. Root amputation, hemisection, and transformation of molars into premolars
   1. Root amputation:

• Is the resection of one or more roots of a multi-rooted tooth
• The affected root or roots are cut at the junction of the root and the crown
• It is performed by horizontal section to separate the root from the crown
• The integrity of the crown is preserved and the root segment is extracted

2. Root hemisection:

• Is the surgical division of a multi-rooted tooth.
• The division of the mandibular molars is vestibulolingual at the level of the root bifurcation
• The division of the maxillary molars is mesiodistal to the bifurcation with the palatal root
  • The defective root or roots or the one with affected periodontium and the corresponding coronal portion are then extracted.
  • It consists of vertically cutting the tooth from the crown to the inter-radicular region, which results in the separation of two hemidents (crown and root held on the arch).

3. Indications and contraindications for root amputation or hemisection:
   1. Indications:

• Periodontal disease resulting in severe bone loss around the roots or inter-radicular areas that cannot be recovered by periodontal surgery
• Compromised root treatment containing a fractured instrument, perforations, carious lesions, resorptions, vertical root fracture or calcified canals
• Preservation of one (or more) roots with their strategically important crown

2. Contraindications:

• Insufficient bone support
• Fusion or proximity of roots preventing any separation
• Need for a strong bridge abutment
• Inability to perform root canal treatment in the remaining root(s)

4. The transformation of a molar into a premolar:

• Is typically the surgical division of a mandibular molar while retaining both halves of the crown and root
• It consists of a vertical section through the crown to the inter-radicular region by means of a fissure burr
• The result is the complete separation of the roots and the creation of two separate crowns

1. Indications and contraindications for the transformation of a molar into a premolar:
   1. Indications:

• Perforation of the interradicular region
• Periodontal disease in the interradicular region
• Vestibulolingual cervical caries or fracture in the inter-radicular region

2. Contraindications:

• The distance between the floor of the pulp chamber and the external surface of the inter-radicular region is significant (thick floor)
• A hemi-tooth cannot be restored
• Periodontal disease
• Inability to perform root canal treatment in each hemident
• Fusion of roots
• severe periodontal disease

10. Conclusion :

Tooth extraction remains the last resort in the event of failure of endodontic treatments , endodontic surgery can compensate for cases of failure.

The healing process is long, but success depends on keeping the tooth in the arch.

Endodontic surgery

  Wisdom teeth can cause infections if not removed in time.
Dental crowns protect teeth weakened by cavities or fractures.
Inflamed gums can be a sign of gingivitis or periodontitis.
Clear aligners discreetly and comfortably correct teeth.
Modern dental fillings use biocompatible and aesthetic materials.
Interdental brushes remove food debris between teeth.
Adequate hydration helps maintain healthy saliva, which is essential for dental health.

Endodontic surgery