*5.3. Voltage-Gated Potassium Channels*

Patch-clamp recording revealed the presence of the voltage-gated potassium channel (KV channel) in cultured human dental pulp cells [175] and in human odontoblasts [73]. Calcium-activated potassium (KCa) channels that display mechanosensitivity are also present in odontoblast cells [30,31,176], and their concentration at the apical pole of odontoblasts could have relevance in the sensory transduction process of teeth [73].

#### **6. Conclusions**

Tooth pain greatly undermines patient quality of life. Tooth pain arises from distinct mechanisms from other pain types because of the unique neurochemical properties and anatomical structure of dense innervation and vascularization under hard tissue. The physiology of tooth pain involves the complex orchestration of ion channels introduced in this review (Table 1). Still, the present understanding is vague. Many questions remain, such as how mechanosensitive ion channels involved in tooth pain are molecular identified, whether odontoblasts function as primary sensory cells, and, if so, how they provide signals to underlying nerves. Elucidating these questions will provide the basis for understanding tooth pain and can lead to the development of therapeutics specifically targeting tooth pain.


**Table 1.** Tabular summary of ion channels expressed in dental pain sensory system and their functions.


**Table 1.** *Cont.*

**Funding:** This work was supported by the National Research Foundation of Korea (NRF) grant (NRF-2018R1D1A1B07049067, NRF-2017M3C7A1025602 and NRF-2015R1A1A1A05027503) funded by the Korean government.

**Conflicts of Interest:** The authors declare no conflict of interest. All authors approved the final manuscript.

#### **References**


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