For your hometown dental clinic experience:
Take a letter on the clinic letter head mentioning your duties, salary, the time period you served etc , to be signed by the owner with his contact details etc
Take a salary certificate on clinic letterhead
Attach your IT return (it should have included the payments received from this clinic)
Attach a your declaration that these are small time clinic and do not issue a formal appointment letters, reliving letter etc
CIC may visit, call the people you mentions here. Or they may call you for interview etc. Do not manuplate with any facts or figures
You should mention your teaching experience, however it does not help in qualifying your application as dentist.
They ask for appointment letter which mentioned duty hours, salary, period of job.
About giving info about teaching experience, they not want teachers if he will mention that he is teaching somewhere then he cannot show that he is a full time worker somewhere .
they clkearly stated that part time job working experience should not be counted.