Non Surgical Management Of Teeth With Periapical Pathosis Endodontic surgery is certainly not a recent innovation . Incision and drainage efforts for the relief of swelling and pain are known to have been performed in the 4th century and were in practice until more definitive techniques were introduced in the 19th century . As endodontic concepts improved, polarizing disagreement developed as to its importance and necessity. As a result of the careful evaluation of clinical practice and with the maturation of the field of endodontics, it has become apparent that it is no longer appropriate for a dentist to take a firm and stubborn stand in relation to endodontic surgery. The time has long passed for “never surgery” or “always surgery”, two conflicting schools of thought to be supportable in clinical practice or theory. Surgery is not always a necessary step in endo, but it is an integral part of endo therapy. It is necessary to correct the established view that sees conservative endo as opposed to surgical endodontics. Surgical removal of perapical tissue is attended by complete tissue repair in the great majority of cases. The resection of periapically involved teeth has come to be universally accepted as one of the most effective means of eradicating residual infection that may have remained in the periapical tissues. In order to understand the purpose of root resection more thoroughly, we must become familiar with the etiology of periapical pathosis. 1- Trauma, from overinstrumentation, will cause injury to the periapical tissue, with or without the presence of microorganisms. 2- Infection, which has broken down the defensive forces within the canal, will cause periapical inflammation. 3- Tissue irritating drugs used in treating canals will result in damage to the periapical tissues.The amount of irritation produced is directly proportional to the size of the apical foramen, the nature of the drug, and the length of time it has remained in the canal. 4- Irritation resulting from interchange of foreign proteins accumulating in poorly filled canals. 5- Mechanical irritation resulting from excess root filling may cause bone resorption in the periapical region during masticatory movement. The hollow tube experiment : Rickert & Dickson studied the tissue tolerance of various types of root canal filling materials. They found that non-irritating substances, like silver, gold and gutta-percha, showed no foreign body reaction when sealed into the peritonium of the rabbit. However when porous substances such as wood, or hollow glass or platinum tubes were used, an extensive inflammatory zone was noted at each end of the hollow tube. This didn’t happen with solid tubes of the same materials. This may account for the tissue reaction around the apices of teeth whose canals are sterilized , but improperly filled. Periapical tissue fluids will accumulate in the empty space in the canal, stagnate, and later escape into the surrounding periapical tissues where they act as irritating products of protein degradation. The mountain pass concept!!! (Kronfeld 1955): The bacteria in the root canal can be compared to an army waiting behind high, inaccessible mountains, the walls of the canal. Through the mountain pass the apical foramen, this army tries to invade the plain beyond the pass, the periodonal tissue and the rest of the body. Another army in the plain guards the pass, the granulation tissue, which tries to prevent the mountain army from progressing farther. The defending army is represented by the white blood cells and other cells of the granulation tissue. Naturally the soldiers of the defending army are grouped closely around the opening of the pass through which the enemy is trying to come; for the same reason the white blood cells accumulate near the opening of the apical foramen. For a long time there may be no action. Occasionally, a few soldiers of the mountain army descend through the pass, the apical foramen, but they are usually captured and destroyed by the defenders, the white blood cells. Then suddenly the mountain army makes a mass attack and a battle occurs. Such a battle between invading bacteria and body tissues is known as acute inflammation. The outcome of this battle may vary!!! The bacteria may win and invade the plain; then the clinical manifestations are an acute periapical abscess, or even a general septic infection. Or the defenders (WBCS) may be successful; they may overcome the invading bacteria, and afterwards the rest of the mountain army will again be confined to the canal, for which the WBCS have no access. If the attacking mountain army, the bacteria, are eliminated, either by: - extraction of the tooth, or by - sterilization of the root canal, the defending army is no longer needed!!! The granulations shrink, and the soldiers, the WBCS, leave and return into the general circulation. This explains why the apical granulation tissue disappears after extraction or after successful RCT. So the granuloma is a defense against spread of infection. It is this tissue with its newly formed capillaries, which constitutes the granulation tissue by which repair of open wounds, abscess cavities, etc.., takes place. Definition of granuloma & granulation tissue!! A granuloma is an inflammatory exudate composed of polymorphonuculear leukocytes, lymphocytes, plasma cells and histiocytes. These are defense cells with antibacterial and antitoxic properties. Granulation tissue is a tissue of repair composed of newly formed capillaries, fibroblasts, and inflammatory cells. This concept is of fundamental importance in the way we should look at the idea of root resection, which is surgical removal of the natural defensive and reparative mechanism. On the other hand, if we cleaned the canal out of bacteria, no further irritation is present and proliferation of blood capillaries and fibroblasts take place inside the granuloma to form granulation tissue, which is the first step to affect repair. Bacteriologic status of periapical tissues following treatment!! Hedman ( 1951) carried out bacterial examination of periapical tissues of teeth with periapical rarifaction. He used sterile canula through which seven sterile wires, bent at different angles, were inserted at different angles in the periapical area, to take bacteriologic cultures from the periapical lesion. He concluded that : 1- In a large percentage of cases of infected pulp, involved teeth with periapical pathosis, the periapical tissues were infected. 2- After complete pulp canal cleaning, in which negative canal cultures were obtained, the infection in the periapical tissues was resolved without residual infected foci. Before that experiment it was impossible to take cultures from the periapical lesion to determine its sterility. It was for that reason that doubt existed about the efficacy of RCT in healing of periapical lesions without root resection. And resection was thought of as the only way of resolving periapical infection. That’s to say because they couldn’t take cultures to relate the idea. The fact that bacteria cannot be recovered from the periapical tissues, after the sterility of the canal has been established, demonstrates the effectiveness of the defensive function of the cells in the periapical granuloma. Root resection or apical curettage removes the tissues which nature has laid down as a defense and reparative tissue. By removing it, the return to normal bone is considerably retarded. This is in agreement with the mountain pass concept of Kronfeld. However it must be understood that not all radiolucent areas are infected. If the concepts by Hedman and Kronfeld are correct, osteogenesis should occur when the cause of periapical pathosis is eliminated. The following factors are no longer considered to be automatic indications for surgery: - An extensive periapical radiolucency. - Cystic involvement. - Failure of root canal therapy. - A fractured instrument in the apical 1/3 of the canal. - Iatrogenic root perforations. - Crater-shaped resorption of the apex. - An incompletely developed apex. - Overfilling of the root canal. - A horizontal fracture of the root apex with pulpal necrosis. - Persistent positive cultures. The current practice is to remove the canal contents and obturate. The current concept: In summary, the role of surgery has changed dramatically with the maturation of the field of endodontics. The current concept is to treat a tooth nonsurgically and to follow the progress of therapy by periodic clinical and radiographic examination. Bacteria in the periapical lesions: Recent studies have shown that some bacteria can live in the periapical area without being present in the canal. Some bacterial species like Enterococcus fecalis have this ability. Other types like strains of Actinomyces Israeli form a bacterial biofilm on the outer root surface which canot be phagocytized by the tissues. These findings explain why post treatment disease occur in some cases that were properly cleaned and obturated.
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