The phenomenon of degeneration and regeneration of nerves pulp

The process of de-and regeneration Innervate the teeth alveolar nerves are not in the field of view of the practitioner, meanwhile with them constantly have to face in the clinic. Injuries (mainly fractures), neoplasms, osteomyelitis, operational intervention at the jaws, sinusitis usually accompanied by damage to the respective alveolar nerves. Especially often have to deal with injuries of nizhnelenskoe mandibular nerve in anesthesia and the removal of the lower teeth. Much less (but more often than is commonly thought) observed infectious neuritis alveolar nerves.
In all these cases are degenerative processes in the nerves, which are accompanied by pronounced inflammatory and degenerative phenomena in the relevant sections of tooth-jaw system. As degenerative processes in the nerves are replaced by regenerative, pathological phenomena in the relevant tissues (except, of course, irreversible) gradually wane. All the above applies, of course, and to the pulp. That is why a clear understanding of how processes are de - and regeneration of nerves in the pulp, the ability to trace the dynamics of these processes are highly important, as it allows the doctor to intervene and accelerate the processes reinnervation is detected and thus prevent irreversible changes in the pulp and therapeutic measures at our disposal).
The problem of degeneration and regeneration affection of peripheral nervous system devoted great literature. However, the study of these processes in the alveolar, and especially in dental nerves paid very little attention. On this question there are only fragmentary information.
Burning out of gasserv site in cats and dogs, I. M. oksman (1947) after 48 h after the operation was observed in the nerves of the pulp appearance vacuoles and varicose swelling along the axis of the cylinder and a more intense color. Only single fiber was at the stage of disintegration. Through 51-64 h comes typical villerusa degeneration of the vast majority of nerve fibers; makunia shell break into the ovoid. Through 96-120 h after injury visible resorption process collapsed nerve fibers. But among them you can see the subtle nerve fibers that are only in the stage of irritation. The author believes that these fibers are sympathetic to (walking, therefore, directly from cervical edge of the trunk).
P. I. gehrke (1947) produced one - and bilateral transection signalvaluerole nerve puppies. In the first day after surgery, the author observed increased argentophile nerve fibers pulp and periodontitis. On the second day during axial cylinders appeared varicose thickening and vacuoles. On the 4th day marked the nerve fibers disintegration; on the 14th day - full resorption of decay products in the pulp of teeth. On the 16th day was observed growing in the nerve fibers of the scar in the peripheral segment damaged nerve. On the 30th day of the recycling fibres were found in the pulp premolar.
Most in detail the process of de-and nerve regeneration pulp after transection signalvaluerole nerve traced Century A. Kuritsyna (1959). After 6 h after the operation in the nerve fibers of the pulp and periodontal the author observed changes in the form of increased argentifolii and education varicose swelling along the axis of the cylinder. Within the next 6 hours describes the changes in the axial cylinders was increasing and at the same time, he noted the collapse of the fragments axial cylinders most of the nerve endings and preterminal fibers as in the pulp and the tissues. In makalnyh fibre pulp and periodontal marked paler than normal, color and appearance of bulges in the course of fibers (which is considered to be the sign of irritation). After 24 hours in the terminal and preterminal nerve fibers pulp was observed resorption process of the decay products of axial cylinders. Part of small makalnyh fibers is by this time in a stage of disintegration. In larger determined narrowings caused by the collapse of the axial cylinders.
In the next day was observed almost complete collapse of the axial cylinders and makalnyh shells in the nerve bundles pulp. Among them met only a few thin nerve fibers under irritation. Well seen resorption of decay products in the terminal and preterminal fibers. A complete resorption ended in 1-1,5 weeks after surgery.
Two weeks begins neurotization pulp and periodontitis. Reinnervation of spreading gradually from 5 posterior tooth to the cutter. After 3 weeks in 5 main tooth already visible Mature makunia fiber with highly visible interceptions Ranvier and thin makunia nerve fibers in the fourth and even the third indigenous teeth. On the 30th day the number of regenerated nerve fibers increases. Increases and their diameter. Most of the fibers covered maketime shells with distinct interceptions Ranvier. In the pulp and periodontal molars by this time already visible nerve endings. After 1.5-2 months after the operation the number and diameter makalnyh nerve fibers continue to grow, but do not reach the normal level. Nervous same end almost fully restored. Through 90-120 days regenerated nerve fibers and the number and diameter of close to normal (except cutter).
Denervation, coming after transection signalvaluerole nerve, as already indicated, leads to inflammatory and dystrophic processes in innervated the region. The same processes are observed in the pulp. After 6 h after surgery, blood vessels pulp and periodontal dramatically expanded and filled with blood. In the next 6 hours are determined by the swelling of the pulp and periodontal and low infiltration their cells. After 24 h marked the stasis of blood in the vessels of the pulp and periodontitis, as well as increased swelling and infiltration of connective tissue cells (with a predominance of lymphocytes). In the next day swelling and infiltration of lymphocytes, is particularly well expressed in the base and top of the pulp, is increasing. After 3-5 days the expansion and full blood vessels in the pulp and periodontal continue to hold. Infiltration of lymphocytes pulp is growing, clumps of lymphoid become rounded. In isolated cases in the pulp is detected net atrophy with the formation of the parietal vacuoles in the layer of odontoblasts. On the 7th - 10th day vasodilatation in the pulp and periodontal keeps, tissue swelling and infiltration of lymphocytes are saved. In some cases in the pulp of teeth formation occurs in large wall cavity surrounded by connective tissue capsule. Inside the cavity are liquid, degenerative altered cells pulp and leukocytes.
On 14-21 day after surgery continue to see a sharp dilation of blood vessels, connective tissue swelling and infiltration her lymphocytes. On the 30th day come a slight narrowing of the blood vessels and reduce infiltration of connective tissue lymphocytes.
With the onset of reinnervation is detected pulp and periodontal come reduction of the diameter of the blood vessels, decrease swelling and infiltration of white cells of the connective tissue (C. A. Kuritsyn, 1959).