Would vitamin b5 (pantothenic acid) help in bruxism?

Unlikely: Try stress relieving methods and a mouth splint that your dentist can make for you. Also, patients with sleep apnea tend to have bruxism. If you suspect you have sleep apnea consult your doctor for a sleep study.

Bruxism management: There are no studies that support the efficacy of vitamin B-5 in bruxism management. Various approaches to the management of bruxism include: oral appliances, medications and behavioral interventions.

See a TMJ/TMD Dr.: Someone may grind their teeth for a number of reasons. Often, the problem occurs because the muscles of the face and jaw are trying to get the teeth in a comfortable position. The muscles may be in spasm, you may have a tmj/tmd problem, stress, infection. Best to see a dentist asap. Often the cause is difficult to determine, so may have to treat the symptoms with a mouthpiece.