Note 4 - Inventories (Details Textual) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Inventory Write-down			$ (2,061)
Slow Moving Medical Finished Goods [Member]
Inventory Valuation Reserves, Ending Balance	$ 450,000	450,000		$ 450,000
Slow Moving Dental Finished Goods [Member]
Inventory Valuation Reserves, Ending Balance	9,500	$ 9,500		$ 318,000
Inventory Write-down	$ 308,000