What is dentinal fluid?
the lymph or fluid of dentin, which appears on the surface of freshly cut dentin, especially in young teeth; it is a transudate of extracellular fluid, mainly cytoplasm of odontoblastic processes, from the dental pulp via the dentinal tubules. Synonym(s): dental lymph.
What is hypersensitivity theory?
The theory states that dentine hypersensitivity is caused by movement of the dentinal tubule contents. Various stimuli alter the flow and pressure of the tubule fluid and thus by hydrodynamic action these changes are detected by the mechanoreceptors surrounding the odontoblast processes.
What produces dentinal fluid?
Stimuli, including air blasts, cold, and hypertonic sugars (“sweets”), can produce dentinal tubule fluid movement (Fig. 2–2). Movement of this fluid results in stimulation of nociceptive nerve fibers located on the pulpal side of the dentinal tubules.
Why do we feel pain heat cold etc in your teeth?
Tooth sensitivity triggered by heat or cold tends to occur when a tooth’s outer protective layer, the enamel, has worn down. Enamel covers the parts of a tooth above the gums. A loss of enamel can expose the sensitive dentin of the tooth, the layer below the enamel that allows heat and cold to stimulate nerves.
What is Interglobular dentin?
Interglobular dentine (IGD) is an area of poorly mineralized dentine matrix. It has been reported that there is an association between the retraction of odontoblast processes (OP) and the formation of IGD. A variation of the extent of OP has been described depending on the region of the tooth and age.
What causes dental hypersensitivity?
Sensitive teeth are typically the result of worn tooth enamel or exposed tooth roots. Sometimes, however, tooth discomfort is caused by other factors, such as a cavity, a cracked or chipped tooth, a worn filling, or gum disease.
Which of the following teeth are most affected by hypersensitivity?
All teeth are susceptible but canines and premolars are the most affected.
What do dentinal tubules contain?
The dentin tubules contain an arm-like soft tissue extension, the odontoblast process, and fluid composed mainly of various proteins.
Why are dentinal tubules S shaped?
The “s”-shaped curvature of dentinal tubules indicates the course taken by the odontoblasts during dentinogenesis. This “s”-shaped curvature results from crowding of the odontoblasts as they move from the periphery toward the center of the pulp.
Why do teeth hurt at night?
The main reason why toothaches are more painful at night is our sleeping position. Laying down causes more blood rush to our heads, putting extra pressure on sensitive areas, such as our mouths. We don’t feel that throbbing sensation as much during the day because we’re mostly standing or sitting.
What is thermomechanical pulp?
Thermomechanical pulp (TMP) is mainly used for mechanical printing papers such as newsprints as well as uncoated and coated magazine papers. The invention and development of thermomechanical pulping process in the 1970’s rapidly changed the structure of the world’s pulp and paper industry.
What is the pulp of a tooth?
The pulp is the part in the center of a tooth made up of living connective tissue and cells called odontoblasts. The pulp is a part of the dentin–pulp complex (endodontium). The vitality of the dentin-pulp complex, both during health and after injury, depends on pulp cell activity and the signaling processes…
What are the two types of mechanical pulps?
Two major mechanical pulps are thermomechanical pulp (TMP) and groundwood pulp (GW). In the TMP process, wood is chipped and then fed into large steam-heated refiners where the chips are squeezed and fiberized between two steel disks.
Why is the energy consumption of thermomechanical pulping so high?
The high energy consumption of thermomechanical pulping and ineffectiveness of the refining process probably derives from having a too low frictional force that heats pulp and evaporates water without any changes in the fibre structure.