Yes. Sperm counts caused by varicocoele's (dilated scrotal blood vessels), fallopian tubes can be sometime "unblocked", closed cervices (stenosis) can be opened surgically, and ovulation induced. Those are some examples of reversible infertility.
What is Question? If you want a "permanent contraceptive" that is "reversible" then we really do not have one. "permanent" contraception can sometimes be reversed like tubal ligation or vasectomy, but the success rates are considerably lower than normal fertility. We have very effective contraception (less than 1% failure) if you think you may want more children. Chat with your doc about options.