Can any diseases be transmitted via pin pricks? i teach sewing and often prick myself with student's pins in which they have pricked themselves with.

Unlikely but possibl: There are blood borne diseases that can be spread by anything with infected blood that penetrates your skin. There are a lot of studies that assess that risk, and solid needles are very unlikely to spread disease. It is still important to not expose yourself to that risk. Keep in mind that the pins would have to penetrate deep enough to draw blood to be infective.