Endodontic surgery.
- Surgical treatment of endodontic pathology should be discussed only when the therapeutic is impossible.
- Before selecting a surgical method of treatment, must be identified the cause of the preceding failure.
- Modern periapical surgery in it's arsenal has operating microscopes, microsurgical instruments and specific materials for retrograde filling.
- Any surgical treatment should be conduct under the constant supervision and should be brought to an end.
Though traditional dentistry should be the preferred method of endodontic disease, there are cases when however is needed a dental surgery. If the attempt to solve the existing problems through the therapeutic means failed, the physician should make every effort to establish why it happened. Dental surgery is indicated only in cases if it is established that therapeutic treatment is either impossible or useless.The indications for endodontic surgery.
Though operations of dental surgery carried out mainly in the case of unsuccessful therapeutic treatment, there are other indications. Dental surgery may be necessary to create a drainage biopsy of the defect; remove any defects and perforations of the tooth root, amputation of one of the roots multirooted tooth, when due to technical reasons one of the roots can't be cured successfully.
Biopsy of periapical center.
One of the specific indications for endodontic surgery - doubts about the nature of the source of degradation. The contents should be completely excised and sent for histological examination.
Root apex resection (apicectomy).
The term of apicectomy denotes only one of the stages of the operation. The main purpose is to seal the canal system by sealing the apical foramen of the periodontium. To do this - it is necessary to reject the apical part of the root to provide access to the canal. Root apex resection is not a self-interference, but the only additional measure for orthograde treatment (dental surgery).
This is for two reasons. Firstly, the chance to seal all the lateral branches of the main canal that connect it with the periodontium by the method of retrograde filling is minimal. Secondly, the coverage area of a filling material in such a case should be larger. Thereby the long-term prognosis will become worse, as all the filling materials to some extent make an irritating effect on the surrounding tissue.
Indications for resection of the apex.
Improvement of the methods of surgical dentistry in the treatment of canals reduced the need for periapical surgery. Cases - seemingly obvious candidates for endodontic surgery may yield to conventional treatment with a thorough understanding of the etiology of disease. Once the decision about the operation with the methods of dental surgery is accepted, you should weigh the chances of success. The basic is a good access and review of the surgical field, otherwise the end result will be counterproductive.
The decision to the operation can be taken if the root canal treatment has failed and re-treatment with the therapeutic method may not be effective. There are several reasons why a traditional therapeutic treatment is unsuccessful. But basically it is an inadequate cleaning and sealing of the canal system. Some filling materials can be very difficult to remove, such as hardening pastes. Sometimes the failures are due to anatomical features. For example, it is impossible to seal the apical delta. An attempt to retreatment by an orthograde access may fail because of inability to pass the canal. Thus, the endodontic surgery and retrograde filling ensure the sealed closure of the apical opening.
Filling material, moved out of the apex may also condition the unfortunate result, as it is an indirect sign of inadequate apical seal. At the same time the decay products that are contained in the apex can penetrate into the space between the root filling and canal wall. In addition, filling materials themselves can be a strong irritant and cause various complications.
Problems that arise during the therapeutic treating of canals.
During the traditional therapeutic treatment of canals can be problems. The reasons may be the following:
- Open apical hole
- The presence of a pin in the canal that is hard to extract
- An unusual configuration of the canal
- The presence of an additional canal
- Obliteration of canals
- A fragment of the tool in the canal
Open apical hole.
Teeth affected before the end of the formation of the root, you must first attempt to treat by the traditional way. If the pulp is vital - then a coronal part of the pulp is removed and the remaining root vital part of the pulp is covered with calcium hydroxide to allow the root to continue their development (apex-genesis). If the pulp becomes inflamed irreversibly, then the root of it is removed and the canal filled with calcium hydroxide to give the opportunity to complete the formation of the root and the apical foramen (ApexiFication).
However, if the treatment fails, it may be necessary for surgical intervention. It will allow to achieve apical hermetic after the sealing of the orthograde canal.
The presence of the pin in the canal.
Endodontic surgery may be indicated for teeth with symptomatic periapical hotbeds, when the actual construction of pins are in satisfactory condition, and the main part of the canal is well sealed. However, success depends on the reliability of the obturation the canal system. Therefore, if there is any doubt, it is better to remove the crown and pin and conduct orthograde treatment without surgery, thereby providing a firm basis for further restoration. However, removing the pin tumbler constructions does not always go without problems.
You should estimate the length and shape of the pin, the strength of the remaining tooth tissues, and, if it is possible, the type of the cement that was used for the fixation . Unreasonable use of force during the removal of the pin can lead to fracture of the root and tooth loss.
The unusual configuration of the canal.
Processing the canals with intricate morphology may be impossible. Similarly, under-developed apical delta, a complete cleaning, shaping and obturation of the canal may not be possible and in addition to the orthograde may require the surgical intervention.
Additional channels.
Modern endodontic techniques should help to form canal adequately, thus providing the opportunity to carry out an ample irrigation with a solution of sodium hypochlorite over the entire volume of the root canal system. Unfortunately the infected decay can sometimes remain in the lateral and additional canals. Although you can try to make an orthograde revision, surgery may be the only option, especially if these canals form the apical delta, which can be liquidated by resection.
Obliteration of the canals.
Long existing processes lead to the deposition of the secondary dentin with a consequent reduction in size of the pulp chamber and root canals. Even more deep sclerotic changes may occur in the teeth after the trauma. An irreversible asymptomatic pulpitis may lead eventually to sclerosis of the canal system. The channels are then almost completely obliterated, and ultimately may be impossible to identify the canal, even with the help of the thinnest instruments. Under such conditions long search for the canal can lead to damage and excessive reduce of the root, up to perforation. Thus the periradicular surgery becomes the only alternative to removal.
Fragments of tools in the canals.
Break off a tool in the canal does not necessarily lead to failure. If it is possible, they should be removed. If this is impossible, then it is worth trying to seal the rest of the canal with the instrument inside. The need for surgical intervention occurs only when symptoms remains or radiologically detected no recovery.
Surgical treatment may be needed to eliminate the defects on the surface of the root that have arisen as to cause of disease and to iatrogenic causes. The two main indications are the following:
Perforations.
First, if there is a possibility should be used orthograde access for closing perforations, ideally - by using mineral trioxide aggregate (MTA). If this is not practicable, the canal must be thoroughly cleaned and filled with calcium hydroxide paste to dehydrate it and give the tissues time for recovery. Then the prepared space of the canal should be sealed by the conventional methods. Perforation due to errors in tooling, can usually be cured by orthograde access if there is generally a convenient approach.
However, with the continuing symptoms or bone resorption or extensive perforation may be necessary surgical intervention.
The outer root resorption.
An internal root resorption should try to cure by the orthograde access. If the resorptive process perforated the root to the periodontal ligament, to restore the root and effective sealing may require surgical intervention. Some types of external resorption at the early stages are amenable to surgical treatment, if there is the operational access to the area of resorption.
Amputation of the root or root hemisection.
Endodontic surgery of the lateral parts of the teeth is more complicated in comparison with interventions in the teeth in the anterior part. For this reason, may be considered simplified methods of amputation and hemisection of the roots. Changes in methods of treatment of endodontic and periodontal diseases in recent years have significantly improved the prognosis for such treatments. The main indications are - endodontic, periodontal and reconstructive surgery. The operation of tooth root amputation consists in removing entirely one of the roots of multirooted tooth, and the crown remains intact. Hemisection -is the separation of the tooth, often in the cheek-tongue plane. Usually the part of tooth is removed, but sometimes both segments are left. This can take place if the disease affects only the area of bifurcation. However, the problems of restoration after such treatment are essential. For this reason, the prognosis is mainly unfavorable.
Anamnesis of patients.
Although there are few absolute contraindications to endodontic surgery, it is necessary to conduct medical records carefully. Most often, heart disease, diabetes, disorders of the blood, the debilitating disease and the treatment with the steroid hormones can be the cause for contraindications to surgery. And, if however it is planned, under such conditions may require special preparations.
It should be also analyzed psychological aspects. As a rule, during the intervention is preferred local anesthesia, but patients with the expressed feeling of fear may wish to all surgical procedures were performed under general anesthesia. The choice of anesthetic is caused by type of surgical intervention, group affiliation of the tooth and the complexity of access.
The presence of rheumatic fever is not a contraindication to endodontic surgery, if it is held under the cover of an appropriate antibiotic. If you have any doubts about the patient's ability to transfer any surgical intervention, it is always necessary to consult the appropriate specialist.
Should decide whether it is worth to save the tooth and how important it is for the entire treatment plan. Attention should be paid to the general condition of the mouth, both soft and hard tissues, quality of restorations of the concerned teeth, evaluate the impact of planned interventions on periodontal condition. The presence of bone defects will affect on the size and shape of cutting flap. Impact radiograph will help to receive full information for assessing the status of the tooth, but sometimes required more than one radiograph to analyze the situation from different angles. There should be clearly identified at least 3 mm surrounding to the apex tissues. It should assess the shape of the root, paying attention to unusual twists, the number of apical pores open at the apex as to the factors that are relevant to the operation.
If you have a fistula it should be visualized by x-ray with the entered gutta-percha pin. Access from the cheek or tongue is always preferable, because the palatal approach is complex and should be used only in exceptional cases. One of key factors is responsible for success or failure of the operation - the experience of the surgeon. You should always keep in mind the possibility of referring the patient to the specialist, especially in complex cases.
Endodontic surgery technique.
1. Preoperative preparation
2. Anesthesia and hemostasis
3. Manipulation of the soft tissues
4. Manipulation of the hard tissues
5. curettage
6. Resection of the apex
7. Dissection of the retrograde cavity
8. retrograde filling
9. Muco-periosteal return of the flap into place and suturing
Preoperative preparation.
Although for the most endodontic operations prophylactic antibiotics are not required, the systemic administration of antibiotics may sometimes be necessary to prevent any possible inflammatory events before the operation. It is recommended to assign rinsing with chlorhexidine 0.05%, along with non-steroidal anti-inflammatory drugs (NSAIDs) on the day before the surgery.
Anesthesia.
Local anesthesia is the method of choice. Although troubled patients who can't be controlled with premedication of tranquillizers may be required intravenous anesthesia. At the time of injection with local anesthesia also provided the hemostasis, so required for quality endodontic operation. After the ointment anesthesia, an anesthetic containing epinephrine at a ratio of at least 1:80000, slowly injected into the area surrounding to the operating field. Local anesthetics due to their composition usually provide the proper hemostasis. On the lower jaw, in addition to the infiltration of tissue of the surgical field, should be done an inferior alveolar nerve block. On the upper jaw the palate should be well infiltrate to block the large palatine nerve. In the incisal papilla and in the canal should be also injected a sufficient amount of anesthetic solution to block the nasal-palantine nerve. Local anesthetic should be injected at least 8 minutes before the operation, to have anesthesia been achieved the proper depth and the maximal hemostasis.Manipulation of the soft tissues.
The shape of the flap should provide an unobstructed view of the operative field and to provide free work with the tools. Should consider the following points:
1. The cut should be clear that the flap could be tilted without damaging the edges.
2. The flap should always be full and distributed to a gingival sulcus. Periodontal tissues must be healthy, as any existing disease will negatively affect the healing process.
3. The blood supply of the flap and surrounding tissues should be sufficient to prevent the necrosis after the operation.
4. The boundaries of the flap should lie above the healthy bone and never have to cross any cavities, otherwise the sutures will disperse and recovery will run with the complications.
5. Supporting cuts should be vertical and should not be run over any bony elevations, such as bone elevation in the canine, as healing will be poor, especially in the presence of bone defects.
There are several types of flap, and, although the choice may depend on the size of the source of the destruction, periodontal status, state of the coronal part of the tooth, it usually depends on the preferences of the surgeon.
Full muco-periosteal flap
This type of flap provides the best access to the operating field and may be rectangular with the mesial and distal vertical relaxing incision and triangular, with a vertical incision. The last often provides the best access to the apex of anterior teeth, although the interventions on the posterior teeth distal relaxing incision is not always necessary, moreover, he can make it difficult to suture the wound in the confined space of the mouth. Vertical relaxing incision is carried out at the same angle relative to the gingival edge and that the axis of the tooth, thus capturing the gingival papilla. Horizontal incision is carried out at the gingival margin. Then the flap is gently tilted with raspatory, by peeling the periosteum from the bone.
Semilunar flap.
This is type of flap, when the incision is made in a semi-circle, starting at the apex of adjacent teeth, through attached gingiva and ending near the apex of the tooth on the opposite side. Mentioned only in historical perspective and is not recommended for use. Its main disadvantage is the scarring that invariably accompanies this kind of flap. However, the problems often occur when cutting line passes over a bony defect in cases when in fact the boundaries are wider than planned before the operation.
The flap of Lubke Ohenbeyna (Luebke-Ochsenbein).
This type of flap was designed to avoid some disadvantages of the semilunar flap.
Vertical incision is carried out from the distal side of the adjacent tooth down to a point separated from the gingival margin for 4.0 mm. Horizontal incision is made serrated, repeating the contours of the gingival margin, passing through the attached gingiva to the distal side of the adjacent tooth on the opposite side. The cut should always be extended for the other side of the curb up to distal part of the central or lateral incisor in order to avoid vertical cuts passing through a curb.
The flap provides an excellent overview of the operative field. However, the disadvantage is that the edges of the bone cavity may cross the line of incision, similar to how it can be in the semilunar flap. You must first verify the absence of periodontal pockets in the otherwise an unfavorable outcome is guaranteed.
The aim in this form of flap is to preserve the integrity of the gingival margin if there are artificial crowns on the teeth. Scarring in this type of flap can also be a problem. No matter what form of the cut is used, lifted flap should be protected from injury during the operation.
Manipulation on the hard tissues.
If the destructive process has destroyed the cortical plate, the localization of the source does not make any difficulty. However, if this haven't have happened previously, it is worth to measure the tooth on the radiograph. At first it may be used by a large round bur, heavily cooled by the water or saline. With help of it, small, shallow probe deepening are made to determine the location of the apex and the source of degradation. This must be done very carefully to avoid damaging the surface of the tooth root that is in close proximity. As an alternative way, with the spherical boron, cooling cut of cortical bone plate in the area of the proposed apex location can be done. The bone is cut off very lightly in order to reduce warming tissues and better visibility. Enough bone must be removed with the help of curettes and burs and until there will be a good visual control of the root apex.
Curettage.
The essence of this manipulation is to remove all granulations around the apex with curettes. Sometimes it is impossible to remove all pathological tissues until the tip of the root be resected.
When it is made the intervention on the periapical tissues, the pathological tissue in the hearth of destruction should be possible completely removed. However, the granulation in the periapical source have an extremely high reparative capacity and resistance to damage and if there is a chance of damage to other anatomical structures. This makes it easier, because technically it is very difficult to remove completely all the granulation, especially if they are tightly fused with the walls of the bone cavity.
Remote pathological tissues should be sent for histological examination with a detailed description of the clinical picture.
Root apex resection. (See separate article).
The aim of resection is to make this kind of root that the apical end of the canal was available for inspection and access in a retrograde dissection of the cavity. Approximately 3 mm root apex is removed, and this section will contain almost all the lateral canals.T here is no need to cut the apex to the level of the lower wall of the bone cavity. If it is removed large of the root the canal with a greater cross-sectional area will be available . This causes that the imposition of retrograde filling the large surface of filling material will be in contact with adjacent tissues, thereby reducing the chances for successful recovery. The number of remaining root length will be determinative for further prosthetic with bolted structures.
Carry out this procedure is recommended with using the zoom for more precise determination of the actual direction of the longitudinal axis, and for a detailed study of the root surface on the cut and the canal.
Preparation of the retrograde cavity.
Preparation of the root apex should ideally be carried out with the help a piezoelectric ultrasonic handpiece. One surface cavity is prepared, which includes the canal completely clearing up. Preparation should be done carefully to avoid excessive deepening of the cavity that will not allow to fill it tightly. Errors in the preparation will lead to that the formed cavity will be either overly or insufficiently deep.
Currently for the formation of the retrograde cavity is recommended to use specially designed ultrasonic nozzles at the piezoelectric tip.
They were first introduced in the early 90s of the twentieth century.
Retrograde filling.
Before injecting the retrograde filling material it is necessary to provide hemostasis. Dry, pre-soaked with epinephrine cotton balls can be placed into the bone cavity, hat in addition to hemostasis will prevent accidental removal of the material sealing the root canal. Bone wax or gauze turundas can also be used to isolate the root apex. If you use gauze turundas, you can soak it with saline, and after being placed into the wound covered with a dry cotton swab.
The excess of the filling material is easy to protect with moist gauze For filling must be used biocompatible materials. It is recommended to use stabilized zinc oxide-eugenol cements such as IRM (zinc oxide-eugenol cement modified polymethacrylates 20%) or Super EBA (modified methoxybenzoic acid).
The tip of the root should be dried with paper pins or with a weak stream of air, then the material can be placed on the transporter. After injecting and sealing in the cavity for further condensation and removal of the excess a wet cotton ball can be used .
No matter what material is used for restoration, it must carefully compacted in the cavity with a small plaggera, providing a tight adaptation of the material and then using the tool with the spherical working part the material is lapped at the edges, smoothing the boundaries of the restoration. The bone cavity is carefully processed to remove the chips and excess of the materials entered in it.
Stacking of the flap and suturing.
Once the retrograde filling is finished the final processing is carried out. Then the bone cavity is filled with the osteoplastic materials. The material that we recommend is Bio-Oss ® BIO-OSS is of the domestic Kollapol KP3-A. After filling with it the flap can be sutured. It must always be used a synthetic monofilament suture as preventing the entry of bacteria into the wound and promoting the better healing than using of silk. We do not recommend the use of resorbable suture material.The edges of the vertical aperient cuts are connected by single interrupted sutures. Gingival margin of the flap is placed neatly in the place and stitched with encircled sutured.
Immediately after the suturing the tissues should be tightly pressed with wet gauze for 5 minutes. Postoperative swelling can be reduced by imposing a long cold compress (crushed ice cubes is put in a plastic bag, wrapped in a clean, dry tissue) for up to 6 hours. Postoperative pain can be controlled by introducing of the long-acting local anesthetic at the end of intervention and by the appointment of non-steroidal anti-inflammatory drugs (NSAIDs).
Radiographs must be made immediately after the operation for comparison with images that will be made later to assess the recovery. Ideally around the resected root must be regenerated cement and bone material (if it is radiopaque). That success rate varies from 88% to 92%.
If the treatment was unsuccessful, before taking a second attempt of intervention, should determine the cause of the pre-failure. Repeated interventions have a lower success rate.
