Note 11 - Segment and Geographic Data - Summary of Operations by Geographic Area (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Product sales, net	$ 2,924,707	$ 1,811,386
Dental Segment [Member]
Product sales, net	2,856,658	1,803,586
Medical Segment [Member]
Product sales, net	71,050	7,800
Domestic [Member]
Product sales, net	997,058	720,391
Domestic [Member] | Dental Segment [Member]
Product sales, net	988,908	720,391
Domestic [Member] | Medical Segment [Member]
Product sales, net	8,150
Domestic [Member] | Instruments [Member]
Product sales, net	176,016	525
Domestic [Member] | Instruments [Member] | Dental Segment [Member]
Product sales, net	176,016	525
Domestic [Member] | Instruments [Member] | Medical Segment [Member]
Product sales, net
Domestic [Member] | Handpieces [Member]
Product sales, net	803,134	697,360
Domestic [Member] | Handpieces [Member] | Dental Segment [Member]
Product sales, net	794,984	697,360
Domestic [Member] | Handpieces [Member] | Medical Segment [Member]
Product sales, net	8,150
Domestic [Member] | Accessories [Member]
Product sales, net	17,908	22,506
Domestic [Member] | Accessories [Member] | Dental Segment [Member]
Product sales, net	17,908	22,506
Domestic [Member] | Accessories [Member] | Medical Segment [Member]
Product sales, net
Rest of World [Member] | Instruments [Member]
Product sales, net	425,755	250,104
Rest of World [Member] | Instruments [Member] | Dental Segment [Member]
Product sales, net	383,255	242,504
Rest of World [Member] | Instruments [Member] | Medical Segment [Member]
Product sales, net	42,500	7,600
Rest of World [Member] | Handpieces [Member]
Product sales, net	974,934	830,408
Rest of World [Member] | Handpieces [Member] | Dental Segment [Member]
Product sales, net	954,534	830,208
Rest of World [Member] | Handpieces [Member] | Medical Segment [Member]
Product sales, net	20,400	200
Rest of World [Member] | Accessories [Member]
Product sales, net	20,560	10,483
Rest of World [Member] | Accessories [Member] | Dental Segment [Member]
Product sales, net	20,560	10,483
Rest of World [Member] | Accessories [Member] | Medical Segment [Member]
Product sales, net
International [Member]
Product sales, net	1,421,249	1,090,995
International [Member] | Dental Segment [Member]
Product sales, net	1,358,349	1,083,195
International [Member] | Medical Segment [Member]
Product sales, net	62,900	7,800
CHINA
Product sales, net	506,400
CHINA | Dental Segment [Member]
Product sales, net	506,400
CHINA | Medical Segment [Member]
Product sales, net
CHINA | Handpieces [Member]
Product sales, net	356,400
CHINA | Handpieces [Member] | Dental Segment [Member]
Product sales, net	356,400
CHINA | Handpieces [Member] | Medical Segment [Member]
Product sales, net
CHINA | Devices [Member]
Product sales, net	150,000
CHINA | Devices [Member] | Dental Segment [Member]
Product sales, net	150,000
CHINA | Devices [Member] | Medical Segment [Member]
Product sales, net
CHINA | Other Products [Member]
Product sales, net
CHINA | Other Products [Member] | Dental Segment [Member]
Product sales, net
CHINA | Other Products [Member] | Medical Segment [Member]
Product sales, net