Periradicular apical lesion of endodontic origin Therapeutic
- DEFINITION OF OSTEOCEMENTOGENIC THERAPY
Conservative treatment intervention which allows the definitive, surgical and medicinal elimination of the infectious and necrotic focus
healing of the periodontal ligament and alveolar bone as well as cemental closure of the apex
Healing of the periodontal ligament will allow it to resume its normal functions: proprioception, cementogenesis and osteogenesis .
The apical orifice will eventually become completely obliterated by cementum and the resorbed bone will remodel itself, filling the loss of substance.
2- Anatomophysiological reminder of the periapical region
At the apical level we find several terms to define this region among the following:
The anatomical apex: what we call the apical dome or the vertex in simpler terms is the apical end.
On this anatomical apex we find the apical foramen which is the opening of the canal at the apical level
The radiographic apex: it is the anatomical apex on an X-ray, otherwise explained it is the intersection of an instrument introduced into the canal with the root surface on an X-ray.
Periradicular apical lesion of endodontic origin Therapeutic
Periradicular apical lesion of endodontic origin Therapeutic
- Principles of osteocementogenic therapy:
Conservative treatment of pulp gangrene with or without apical periodontitis consists of:
To remove gangrenous tissues (necrotic and infected) and to disinfect the entire pulp cavity to sterilize it. To make impossible the life and development of germs that could persist. To make impossible the further development of any new microbial flora in this cavity.
1. Remove gangrene:
It is necessary to remove:
Microscopic elements: microbes.
Chemical bodies: toxins, enzymes and degradation products.
Macroscopic elements: this is the organic matter represented by dead tissues destroyed in part or in whole.
These elements are located in the main canal, secondary canal and in the canaliculi.
Gangrene removal must be twofold:
-Instrumental, mechanical, it is curettage, “root canal trimming”
– Chemical, it is “disinfection”
2) Make impossible the life and development of germs which could persist:
If it is well executed the first time, a second trimming is not necessary; but the chemical action can be renewed if it is thought that it has not carried well into the most remote spaces, or if the chemical activity does not seem to be the most total:
hence the possibility of a 2nd disinfection session.
hence, even better, the need to use disinfectant processes that reach germs everywhere, inside the endoodontic cavity.
3) Make it impossible for any new flora to develop:
This new flora develops in the event that disinfection has not been done properly. This flora can come from one end or the other of the pulp cavity.
On the apical side: any bacteremic state in the blood circulation of the periodontal ligament can allow anchoritic fixation of germs in the canal; to avoid this, cemental closure is desirable.
The canal obturation must involve the entire length of the canal and must be perfectly hermetic and watertight.
On the coronary side:
Due to the lack of hermeticity of the coronal obturation, the oral microbial flora can reach the periapex and maintain a “latent microbism” which is not tolerable today.
Therefore, the coronal obturation must be hermetic, just like the canal obturation.
4- Indications and contraindications
Periapical lesions follow the same indications as those of other endodontic treatments: that is to say, apart from a few general contraindications that pose a certain risk to the patient, they have no limitations. All periapical lesions apart from large cysts of the mandible or maxilla, and certain periodontal lesions at the terminal stage, can and should be treated with a percentage of favorable results that exceeds 90%.
In the presence of a periapical lesion , the only factors that can lead to extraction are the ignorance and unwillingness of the practitioner or the patient. It is well understood that endodontic surgery compensates for certain impossibilities of conventional treatment.
5-DIFFERENT THERAPIES: 5.1 TREATMENT OF CHRONIC PERIAPICAL LESIONS
Chronic apical syndrome corresponds to all apical lesions discovered by routine radiological examinations and presenting no clinical signs, i.e. from reactive condensing osteitis and apical lesions ranging from simple desmodontal enlargement to established granuloma.
In this case, we are faced with an infected canal with a periapical region in a chronic inflammatory state. If there are no acute manifestations, it is because a certain balance has been created between the microbial irritant from the canal and the body’s defenses. The only acceptable attitude is therefore:
Not to inoculate the periapex by too rapid penetration of the instruments, which should in no case exceed the apical limit,
Not to modify the intracanal bacterial balance, by promoting the preferential growth of certain strains which would cause an acute outbreak: abundant and effective irrigation of the canal is the only solution to this problem
Surgical strategy
Except for the apical limits, the treatment of the canal obeys the general rules of canal preparation, with some nuances that it is good to remember and knowing that the mass sealing of the entire canal system takes on even more importance here.
The therapy aims to achieve: trimming, disinfection and obturation of the canal system
- CANAL TRIM
a) Definition; It is the surgical removal, using endodontic instruments, of all necrotic and infected soft tissues until the complete exposure of the dentinal surface of the canal wall, which must become hard and clean.
Periradicular apical lesion of endodontic origin Therapeutic
b) Objectives of trimming; The main objectives of root canal trimming are as follows:
• First eliminate the very large microbial layer of germs located on the walls of the canal, their favorite place of residence.
• Open and gape the tubules so that the antiseptics can penetrate the dentine and sterilize it
c) Surgical technique; Trimming is done using an instrument, it is therefore a mechanical action, it will be done over the entire length of the canal from its cameral orifice to its apical orifice and corresponds to scraping the walls of the canal.
Trimming will be done as the initial penetration progresses, then the canal preparation; all the principles and steps of canal preparation must be followed, however:
The apical limit; In most cases, the pathological resorption of the tissues of the apical third of the canal, cementum and dentin, leads to the destruction of the cemento-dentin junction; the apical limit of preparation and canal obturation will therefore correspond to the foraminal outlet.
Degree of enlargement and elimination of bacterial load; Infected teeth the layer that must be eliminated (pre-dentin + a few microns of infected dentin) extends over approximately 30/100mm.
It is therefore obvious that in this case the enlargement will have to be pushed up to thirty hundredths or more, that is 5 numbers or more than the first instrument which penetrated to the apex.
B CANAL DISINFECTION
a) Definition; The concept of canal disinfection is based on two ideas:
-Prevention of iatrogenic infectious risks
-Treatment of the root canal infection itself
CANAL DISINFECTION;
Objectives : To make the development of pathogenic endocanal flora impossible
Elimination of the endodontic smear layer which strongly adheres to the canal walls, it is necessary to use solutions acting on organic and inorganic debris
Complete the role of canal debridement by evacuating debris outside the canal.
- TYPES OF CANAL DISINFECTION
Immediate disinfection : “irrigation” ; This is the action of eliminating by washing with an irrigation solution all organic, mineral debris and micro-organisms detached and suspended by the instrumentation
Among the wide range of available or recommended irrigation agents we have: sodium hypochlorite, hydrogen peroxide, sodium dioxide, physiological water, etc.
Periradicular apical lesion of endodontic origin Therapeutic
Intermediate disinfection: Temporary medication is essential to achieve the most complete disinfection possible of the canal network for several reasons:
-The existence of a canal network inaccessible to mechanical and chemical preparation
-The duration of endodontic treatments, often too short for the antimicrobial action of sodium hypochlorite to be maximal
-The presence of bacteria and especially toxins in the dentinal tubules.
The most commonly used disinfectant is calcium hydroxide; some local antibiotics and corticosteroids can also be used.
C CANAL OBTURATION; This is the last step of simple osteocementogenic therapy.
Any canal filling is intended to maintain the therapeutic result obtained by the elimination of organic debris and micro-organisms contained in the canal.
Regardless of the material or method used, the canal must meet certain criteria before it can be considered suitable for a filling.
Authorized opinions consider that the following conditions must be met, namely:
Absence of periapical symptoms
No excessive exudation from the canal
No bad smell
Perfectly dry canal
Negative cultures
And to do this, the obturation must achieve a real, hermetic seal of the canal system, by placing a dense and trimentionally stable obturation mass.
In the case of fistulated apical periodontitis, it will be necessary to fill in the same session.
In the case of non-fistulized periodontitis, good disinfection will be necessary in order to be able to seal it later.
5.2 TREATMENT of acute apical syndrome ; Acute apical syndrome means all apical lesions presenting inflammatory or infectious phenomena at the time of treatment, i.e. suppurative periodontitis, acute apical abscess and recurrent abscesses. An emergency strategy will therefore be applied to them, it being understood that the rest of the treatment is subject to the same conditions and requirements as the treatment of chronic lesions.
a) Acute serous apical periodontitis:
Treatment consists of:
open the tooth,
make the access cavity
immediate trimming and disinfection of the root canal(s),
a root canal filling with calcium hydroxide.
The patient will be seen a few days later to continue the rest of the therapy.
b) Acute suppurative apical periodontitis:
Emergency treatment: Establishing drainage is the only important step in emergency treatment.
It will most often be established by trans-canal route and it is only in cases where it is impossible to clear the canal that we will resort to bone trepanation, at the level of the apex of the tooth (endodontic surgery).
Antibiotic coverage is exceptionally necessary and, most often, analgesics and anti-inflammatories will be sufficient to ensure the patient’s comfort, after drainage and sub-occlusion of the tooth.
Apart from this general precaution, it is a good idea, when opening the pulp chamber, to wedge the painful tooth in its socket between the left thumb and index finger,
After opening the pulp chamber and draining the canal, a question arises:
Should we leave the tooth open or not?
If there is time to thoroughly debride and disinfect the canal, the tooth should be closed when the inflammatory exudate or suppuration has dried up.
If there is not enough time to ensure effective paring, or if suppuration persists, the tooth should be left open for 24 hours at the most; this time is sufficient for proper drainage.
Currently it is recommended to perform a root canal filling with calcium hydroxide and temporarily close the tooth, with antibiotic coverage and monitoring after 24 and 48 hours.
After restoring clinical silence, a routine treatment is practiced, it is the treatment of PAC
It consists of a root canal trimming and disinfection followed by a hermetic and three-dimensional root canal obturation.
c) Acute apical abscess and
recurrent abscess: Emergency treatment: is carried out as previously by establishing drainage, with one difference being that the incision of the suppurative collection must be systematic if it is clean.
The tooth will be left open for 24 hours,
If the importance of the case requires it, antibiotic coverage will be established.
In this case, all arrangements will be made to complete the treatment, including sealing, before the end of the antibiotic therapy which may be extended by 1 or 2 days.
After achieving clinical silence, routine treatment is performed.
If, despite all the preparation maneuvers, a perfectly dry canal is not obtained, the canal(s) will be filled with calcium hydroxide for 1 week, which can be renewed for another week.
Then the definitive canal filling is carried out.
- Special points ; Some atypical situations may be encountered during the treatment of periapical lesions and a certain number of questions may arise outside of the classic treatment schemes.
Inflammatory flare-up during treatment of a chronic lesion
It will most often occur due to septic inoculation of the lesion, by instrumental overshoot or due to insufficient antisepsis, leading to the preferential proliferation of a resistant strain. We are then brought back to the case of acute apical periodontitis, but we will refrain from leaving it open. A second canal debridement will generally be sufficient by controlling the parameters of the preparation (working length) and by looking for a possible additional canal.
Infectious episode during the treatment of a chronic lesion; Antibiotic therapy will be used and, since the canal is already prepared, after 24 hours of drainage, this treatment can be completed or renewed for eight days if calcium hydroxide is necessary. This accident is fortunately rare.
Inflammatory or infectious episodes that do not respond to repeated treatments:
In this case, the cause must be sought, and it will most often be a forgotten canal: incisors, canines, mandibular premolars, maxillary premolars, mesio-vestibular root of the first maxillary molars. It may also be a particularly virulent germ. Enterococci do not respond to any of the antiseptics used in dentistry and no antibiotic except Chloramphenicol. In this extremely rare case, a solution of chloramphenicol ear drops may be instilled into the canal as an exception, if the inflammation does not respond to several successive attempts by conventional means.
Creation of an artificial fistula; It is only justified in the event of major complications after sealing the canal. It will be performed under anesthesia with caution and after having incised and retracted the mucosa to avoid tearing it.
In these cases, preservation of the dental organ is only possible through endodontic surgery, which completes the orthograde procedure.
It also allows for the management of situations made complex by different factors, such as complex and risky prosthetic suprastructures to dismantle, or even factors of iatrogenic origin, such as lacerations, root perforations or the presence of fragments of fractured instruments in the canals and preventing access to their apical third.
Surgical endodontics is really the last chance to be able to keep the tooth in the arch.
Endodontic surgery should be considered as a rational extension of endodontic therapy and not as a radical technique.
Indications for endosurgical therapy;
Endodontics not possible
– accentuated root curvatures
– complex canal system
Instrumental fracture
Incomplete obturation (59% of failures with complications)
Excess of filling materials
Root perforation
Persistent clinical and radiological signs
Periradicular apical lesion of endodontic origin Therapeutic
Periradicular apical lesion of endodontic origin Therapeutic
Contraindications of endosurgical therapy:
They can be classified into 3 groups:
General CI; any general pathology
locoregional CI; inaccessibility to the surgical site
Limitation of mouth opening
Jugal muscle tone
Local; crown/root ratio must be taken into account
root fracture (fracture line located in the cervical or middle 1/3), extraction is also indicated.
A/ Complementary surgical endodontics
1 – Drainage incisions – cyst decompression; This is the immediate complement to endodontic treatment on teeth that have large lesions, asymptomatic or symptomatic, cooled by antibiotic therapy
An incision is made to allow drainage and evacuation of exudates under pressure; a drain can be left in place for 2 to 3 days but, in the vast majority of cases, the incision enlarged by the passage of curettes into the lesion is sufficient.
2 – Persistence of pain or lesions after properly conducted endodontic treatment; In the case of persistent failure after endodontic treatment or retreatment associated or not with complementary antibiotic therapy, surgery may become indicated if there is no sign of healing, or even if the appearance of signs of worsening of the disease, confirms the failure of the previous treatment. In this case, endodontic surgery is indeed a complementary treatment.
3 – Persistence of lesions or pain after treatment ; Complex canal anatomy can make conventional treatment insufficient. This is the case, for example, of certain canals of the mandibular C-shaped premolars or of areas inaccessible to instrumentation and irrigation solutions such as very curved canals, calcifications, resorptions, certain lateral canals, etc. All these non-disinfected areas can be the cause of endodontic failures.
Periradicular apical lesion of endodontic origin Therapeutic
B / Surgical endodontics from the outset ; This is the treatment of choice when all orthograde treatment options are impossible.
1- Apical curettage and apical resection:
2- apical resection
3- Coronal-radicular amputation and root amputation
1- Apical curettage and apical resection:
Apical curettage: corresponds to the elimination of potential pathological tissue from the bone cavity and it obeys 2 intentions:
Eliminate the area of irritation and contamination to which the body reacts.
. Periapical curettage is indicated in the following clinical situations, where the existing orthograde (or conventional) endodontic treatment is considered satisfactory:
Persistent fistula or periradicular inflammation
Foreign material present in the periradicular region and presents symptoms
Antibiotic premedication is the rule
The incision rules to follow are:
The type of incision is chosen based on:
From the seat and nature of the intervention
On the condition of the fibromucosa (thickness, keratinization)
On the state of the periodontium
Suture possibilities
Periradicular apical lesion of endodontic origin Therapeutic
Curettage of the lesion:
Once the pathological area is discovered, curettage of the inflamed tissues is started with the smallest curette. The biopsy bottle should be kept open to receive tissue samples for histopathological examination. If the lesion is very extensive, the larger curettes are used. Once the large pieces of tissue have been resected, the root tip is cleaned with a surgical curette or a periodontal curette (Gracey curettes and dental excavators, of different shapes and sizes, allow access to difficult areas), any excess gutta-percha and/or apical sealant is removed with an endodontic probe. An extra canal or root is checked.
Different resorbable or non-resorbable hemostatic materials have been proposed : Gelfoam, Surgicel, Avitene, Hemocollagène
Sutures:
Immediately after suturing, a damp compress should be slipped into the vestibule and the flap compressed for about ten minutes, in order to allow the formation of the finest possible clot between the internal face of the flap and the bone cortex.
The patient is reviewed at 3, 6 and 12 months for clinical and radiographic monitoring.
Checks will then be limited to once a year.
CONCLUSION: Apical periodontitis, a sequela of endodontic infection, is a pathology that is now well understood.
Inflammatory in nature, they reflect the dynamic fight between intracanal bacterial factors and periapical defense factors.
Self-healing is impossible and destruction of periapical tissues progresses until the endodontic infection is controlled.
The modern concept of PA treatment lies in the preservation of the tooth after disinfection of its endodontic system.
Surgical approach is only justified in limited cases which, due to microbial and/or structural specificities, are “refractory” to conventional first or second-line endodontic treatments.
The prognosis for apical periodontitis is good and the disappearance of the lesions is the rule given the potential for healing of the periapical tissues after resolution of the inflammation.