Dental implants are usually not the only option for tooth replacement, but they are a great option for many reasons. Here is how dental implants stack up against other options for tooth replacement.
Dental Implants vs. No Tooth Replacement
Comparing getting a dental implant with not replacing a missing tooth at all, avoiding tooth replacement is obviously less expensive. You could have your tooth extracted and then just let the area heal into regular gum tissue. However, you aren't guaranteed that the gap will stay as is. Your other teeth might use this as a reason to shift in place, and then you could end up with various gaps in between your teeth. The cost for orthodontics might end up being more expensive than getting a dental implant to cover that space.
Dental Implants vs. Partial Dentures
You could also choose to get partial dentures that could cover multiple tooth gaps. If you have lost multiple teeth at a time, it could make sense to get the partial denture to avoid the expense of having multiple dental implants put in place. That can be an expensive proposition. But you could also choose to get some same-day implants, which are a temporary form of implant to cover the tooth gap. Then, when you have the financing available, you could replace the temporary dental implant(s) with the appropriate treatment.
Dental Bridges vs. Dental Implants
Dental bridges might be recommended to patients with an otherwise healthy set of teeth. A dental bridge uses the structure of adjacent teeth to keep it in place, so it does require your dentist to evaluate the condition of your teeth surrounding a missing tooth. While dental bridges are fairly strong, there is some risk of the bridge causing issues if it breaks away from the surrounding teeth, taking some enamel with it.
As you can see, dental implants are a better treatment method than many of the other, lower cost options for tooth replacement. As for the flaws of dental implants themselves, one of the potential downsides is the risk of implant failure. While not common, it's possible that the dental implant post will not heal correctly with your jawbone and, thus, not provide a stable post for an implant crown. But in this case, your dentist is likely to work with you to default back to one of the other treatment options, so there is little risk.