I was prescribed ibuprofen and amoxicillin after my tooth extraction,for the pass 3 days everything was ok until when i woke up and my urine was dark brown and i have dull pain in my left side,is this a sign of acute liver failure? i'm worried?

Don't worry, you probably do not have acute liver failure. One of the most common causes of dark colored urine is dehydration. Certain foods and medications can also result in a darker color. If you aren't normally hydrated you may also develop kidney stones. Hydrate and see you physician if the pain persists. Here's some more info: https://www.goodrx.com/health-topic/urology/brown-pee-health

The Dentist or Oral Surgeon that did your extraction is responsible for your post-surgical care. He/she may want to refer you to your Physician or a medical facility for evaluation. Dark urine may indicate dehydration. Other than not hydrating properly after your surgery, Dark urine, extracted tooth, and your prescribed medications, are not related.