If antibiotics treat acne and iradicate pus why wouldn't it do the same for periodontal gum abscess that does not involve tooth root? always incise?

Incision needed: A periodontal abscess is extremely destructive, and if not treated promptly, can quickly result in irreversible damage to the surrounding ligaments and bone, ultimately causing you to lose the tooth. The primary goal of treatment is to drain the infection; usually accomplish eds by carefully scraping the pocket lining. Antibiotics may be helpful in eradicating the infection.

Depend on size: The decision on whether to incise a lesion or not depends on the clinical impression by your doctor of the abscess at the time of treatment. Often you need a combination of antibiotics and incision. In the mouth it's a little different than treating acne due to the environment the abscess is in.

Treat the cause: Treat the cause , not symptoms... Periodontal abscess is caused be bacterial colonization in a deep periodontal pocket and should be treated with debridement (scaling and root planing) followed by antibiotics . In persistent case, laser may be used. Cause of the pocket development should also be address ( food impaction due to open contact).

ACNE: Your premise is wrong. Antibiotics do not treat acne and they certainly do not clear leukocytosis (pus).Antibiotics can be used to affect bacterial load not the body's reaction to the bacteria.