Note 10 - Segment and Geographic Data - Summary of Operations by Geographic Area (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Product sales, net	$ 1,648,368	$ 2,425,738	$ 4,349,270	$ 5,350,445
Dental Segment [Member]
Product sales, net	1,609,768	2,404,738	4,303,120	5,258,395
Medical Segment [Member]
Product sales, net	38,600	21,000	46,150	92,050
Domestic [Member]
Product sales, net	997,782	1,000,642	1,949,019	1,997,700
Domestic [Member] | Dental Segment [Member]
Product sales, net	979,182	1,000,642	1,922,869	1,989,550
Domestic [Member] | Medical Segment [Member]
Product sales, net	18,600	0	26,150	8,150
Rest of World [Member]
Product sales, net	650,586	899,760	2,040,287	2,320,409
Rest of World [Member] | Dental Segment [Member]
Product sales, net	630,586	878,760	2,020,287	2,236,509
Rest of World [Member] | Medical Segment [Member]
Product sales, net	20,000	21,000	20,000	83,900
CHINA
Product sales, net	0	525,336	359,964	1,032,336
CHINA | Dental Segment [Member]
Product sales, net	0	525,336	359,964	1,032,336
CHINA | Medical Segment [Member]
Product sales, net	0	0	0	0
Instruments [Member] | Domestic [Member]
Product sales, net	155,028	178,752	277,996	354,768
Instruments [Member] | Domestic [Member] | Dental Segment [Member]
Product sales, net	155,028	178,752	277,996	354,768
Instruments [Member] | Domestic [Member] | Medical Segment [Member]
Product sales, net	0	0	0	0
Instruments [Member] | Rest of World [Member]
Product sales, net	160,814	172,088	614,374	597,841
Instruments [Member] | Rest of World [Member] | Dental Segment [Member]
Product sales, net	160,814	156,588	614,374	539,841
Instruments [Member] | Rest of World [Member] | Medical Segment [Member]
Product sales, net	0	15,500	0	58,000
Instruments [Member] | CHINA
Product sales, net	0	78,000	0	228,000
Instruments [Member] | CHINA | Dental Segment [Member]
Product sales, net	0	78,000	0	228,000
Instruments [Member] | CHINA | Medical Segment [Member]
Product sales, net	0	0	0	0
Handpieces [Member] | Domestic [Member]
Product sales, net	820,133	802,916	1,623,542	1,606,050
Handpieces [Member] | Domestic [Member] | Dental Segment [Member]
Product sales, net	801,533	802,916	1,597,392	1,597,900
Handpieces [Member] | Domestic [Member] | Medical Segment [Member]
Product sales, net	18,600	0	26,150	8,150
Handpieces [Member] | Rest of World [Member]
Product sales, net	479,799	715,124	1,403,751	1,689,459
Handpieces [Member] | Rest of World [Member] | Dental Segment [Member]
Product sales, net	459,799	709,624	1,383,751	1,663,559
Handpieces [Member] | Rest of World [Member] | Medical Segment [Member]
Product sales, net	20,000	5,500	20,000	25,900
Handpieces [Member] | CHINA
Product sales, net	0	447,336	359,964	804,336
Handpieces [Member] | CHINA | Dental Segment [Member]
Product sales, net	0	447,336	359,964	804,336
Handpieces [Member] | CHINA | Medical Segment [Member]
Product sales, net	0	0	0	0
Accessories [Member] | Domestic [Member]
Product sales, net	22,621	18,974	47,481	36,882
Accessories [Member] | Domestic [Member] | Dental Segment [Member]
Product sales, net	22,621	18,974	47,481	36,882
Accessories [Member] | Domestic [Member] | Medical Segment [Member]
Product sales, net	0	0	0	0
Accessories [Member] | Rest of World [Member]
Product sales, net	9,973	12,548	22,162	33,109
Accessories [Member] | Rest of World [Member] | Dental Segment [Member]
Product sales, net	9,973	12,548	22,162	33,109
Accessories [Member] | Rest of World [Member] | Medical Segment [Member]
Product sales, net	0	0	0
Accessories [Member] | CHINA
Product sales, net	0	0	0	0
Accessories [Member] | CHINA | Dental Segment [Member]
Product sales, net	0	0	0	0
Accessories [Member] | CHINA | Medical Segment [Member]
Product sales, net	$ 0	$ 0	$ 0	$ 0