First of all, keep in mind that I am unable to diagnose you because I am unable to examine you, this forum is for educational purposes.
The symptoms that you describe are non-specific, and may respresent a range of pathologies. I am not sure what tests were conducted to diagnose a peripheral polyneuropathy, but this is an uncommon diagnosis to have with only 5 days of symptoms. Rapid onset of weakness such as you describe can occur with conditions such as Guillian Barre Syndrome (GBS), inflammmatory myopathies, toxic neuropathy and spinal cord dieseases. The reflexes are sometimes preserved in early GBS then disappear as the disease progresses. I would recommend a lumbar puncture to evaluate for GBS (associated with a high CSF protein), MRI of your cervical/thoracic spine) and some blood work including CPK, Aldolase, ESR, CRP, B12, TSH, HGB-A1C, glucose tolerance test, monoclonal protein screen, heavy metal screen and paraneoplastic panel. For dentist it is important to test B12 since nitrous oxide (laughing gas) can cause an acute B12 deficiency.
Without further information, it is impossible to predict when your hands will begin to recover. If your diagnosis is GBS, it will depend on you getting appropriate treatment. If your diagnosis is diabetic polyneuropathy (the most common form) it may not get better, but the symptoms can be controlled. I would recommend that you see a neurologist that specializes in neuromuscular diseases.
I hope this has been helpful.