I have a slap tear in my shoulder. is it possible for the tear to heal on its own without a surgery or is surgery theonly way to go? are there any long term effects?

Yes: This is a tear to the glenoid cartiledge. It can repair without surgery however it may take up to 6 months.

No and maybe: No you do not need surgery if you are not locking or catching you can try pt, but if you continue to have pain or start locking then you need surgery to prevent destroying your joint.

Depends: Slap lesions don't heal on their own. There is good data to support that. Not all slap lesions need surgery. If you have no pain or other symptoms nothing needs to be done. If you have pain try physical therapy first. If that fails, you may need surgery to repair your labrum, or tenodese (cut and reimplant in a different location) your biceps tendon. Choice depends on age, activity level etc.

Won't Heal on Own: Although it won't heal on its own it isn't clear from your question whether you are having any symptoms. Learn more here: http://www.Theshouldercenter.Com/labrum-tear-slap-lesion.Htm.