Most sufferers of back pain arrive at the chiropractic offices in the middle of conditions that began months or even years before the pain began. Perhaps it was a car accident, perhaps a habitual postural issue like crossing your legs, perhaps a fall down the stairs when you were a child. A problem that began so long ago cannot be fixed overnight. I like to say, "You've had a ten year head start on me. I'll need a month to catch up."
The dentist might be able to solve the problem quickly by removing the tooth. That solution is not practical for the back, however. Every time you have a back ache, I won't be able to remove a vertebrae. The subluxation is a complex anatomical mechanism, and something that complex cannot be fixed simply. The only practical solution is to slowly help the body heal, restore muscle balance, restore nerve communication, and so forth. Even pain pills may dull the pain initially, but you'll have to return to them again and again if the underlying problem isn't fixed (add to that the list of side effects found on every over-the-counter medication and your health issues may have multiplied).
The long-recommended chiropractic course of patience has been validated by yet another research study. If chiropractic care for chronic low back pain is ended once the pain has been relieved (but before the source of the symptoms has been solved), then the patient is almost certain to get the pain again within a year. Here's a quote from a news article about the study:
Source: Dynamic Chiropractic
...The study suggests patients with low back pain of at least six months duration experience greater improvement following one month (12 treatments) of spinal manipulative therapy followed by "maintenance spinal manipulation" every two weeks for nine months than subjects who receive one month of SMT only (12 treatments) or 12 treatments of sham SMT for one month. Patients in the manipulation and manipulation-plus-maintenance groups improved with respect to pain and disability after one month compared to the sham group, but after 10 months, only the group receiving maintenance care reported significant improvement, whereas the one-month-only group's pain and disability scores had returned "near to their pretreatment level."