Provided that anesthesia with vasoconstrictor not used and as long as dentin impact remains open, there will be a slow continuous outflow of the fluid along the dentinal tubules (0.4 |jl/min/cm2) (Fig. 2.16). It has been estimated that in some tube can be emptied and refilled ten times a day (12).
Restorative procedures implemented by the dental management of caries, fractures and loss of teeth may not be done without injury pulp. It is primarily the cutting action, which cause irritation of the tooth pulp, releasing the frictional heat using rotary tools. Because the thermal conductivity of the dentin is low, mainly lips that harm. Critical to this effect is insufficient water for irrigation (Fig. 2.15). Direct heat injury, as a rule, does not arise, if the procedure is performed far from the pulp. In addition, the frequent beating tooth incorrectly center tools can cause traumatic effects. All of these injuries produce neurovascular responses nature similar to those described above.
Functionally, a unique dentin odontoblast device acts as a Converter of various external stimuli moderate intensity. This allows the tissue components of the peripheral pulp to be informed properly. Thus, in intact healthy tooth limited cold incentive or elastic deformation of the dentin due to sudden heavy load on the tooth transformed into a minute and rapid movements of the dentinal fluid (14). Such motions excite the surrounding nerves, resulting in a quick reflex conclusion reaction, which is immediately after a brief, sharp pain, alerting the individual to the further care. This is an important signal of the system of protecting teeth from overload, leading to the crown or root fractures chewing forces, for example (59).
It is assumed that the odontoblasts and nerve endings, especially in the period of teeth, have a high energy demand. This may be true in Mature teeth. Consequently, despite the limited collateral circulation, peripheral pulp well-vascularized. Blood flow in young adults pulp at rest, during the relatively high compared to other tissues of the oral cavity (50).
Dentin-cellulose complex is uniquely organized for offset microbial threats from caries, as well as other violations external hard fabrics of a tooth in the oral environment. While permeable for bacterial elements by virtue of the dentinal tubules, dentin, however, performs an important function filter significance pulp immune protection. First of all, two mechanisms to account for this effect: (i) peripherally directional flow of dentinal fluid, and (ii) the absorption of bacteria and bacterial macromolecules for the internal walls of tubules (63). Thus, dentin can moderate the impact of harmful elements cellulose, allowing it to adapt and to organize an effective immune response.
Current knowledge of cardiovascular architecture pulp greatly influenced the use of micro-vascular cast method (Fig. 2.11) (68). This technique allows resin to fill in even the smallest capillaries pulp. Vascular cast then it turns out that after corrosive surrounding tissues, may be considered in the scanning electron microscope.
The pulp of a tooth nerves control the pain. Due to its peptide content they also play important functions in inflammatory events and subsequent recovery of tissues (Fig. 2.10). Furthermore, they control the dentin formation (Fig. 2.10).
There are two types of nerve fibers that transmit pain:-fiber to conduct rapid and sharp pains and belong to the myelinated group, while the C-fibers are involved in a dull aching pain and thinner, and unmyelinated.
After injuries and irritation (e.g.. restorative procedures or progressing rapidly caries), the main odontoblasts can die. Because these cells postmitotic cells, they are not capable of regeneration through cell division. New dentin however, could be formed. Such dentinal repair appears through the activities of the so-called repair odontoblasts or secondary odontoblasts. The predecessor of these cells is thought that the population of postnatal stem cells, which are present in the pulp and paper tissue is correct (22). After their recruitment and regulation, mineralizing matrix lay down on the dentinal wall. Repair of the secondary odontoblasts may also against the corresponding wound-healing agent used for the treatment of direct impact of the pulp (see Chapter 4). Consequently, the new generation odontoblast-like cells, capable of making new dentin locally, may develop in the flesh after injury.
Original odontoblasts, here also referred to as primary odontoblasts, produce dentin as in the period of teeth, and after the completion of the formation of root. The fact that intratubular cellular processes remain makes dentin tubular in nature. Thanks to the continued function odontoblasts, the pulp of the tooth space is gradually narrowed over time and old individuals can become so small that endodontic treatment is difficult.
The most recognized function odontoblasts is the formation and maintenance of the dentin. Like many other fabrics-supporting cells, odontoblasts also contribute to the host defense. Aligning the periphery of pulp cellular expansion into the dentin they are thus in a unique position of being the first cell of the face and respond to the harmful elements input dentin of the oral environment (Fig. 2.4).