Dental implants are an investment. There's the financial cost, and the fact that the implant requires surgery, recovery time, and diligence while the implant is being incorporated into your jaw (which is a mechanism known as osseointegration). If you're informed that your dental implant might require some form of protection, it's in your best interests to follow this advice. Fortunately, this protection doesn't require much effort on your part, and you can literally do it in your sleep.
Any recommended protection is to prevent implant overloading, which is more or less what it sounds like. It's the process by which a dental implant is exposed to excessive force (bite pressure) and essentially becomes overloaded. This can lead to bone loss (as the implant is forced further into the alveolar bone in which it's anchored), in addition to soft tissue damage around the implant. Also, the prosthetic tooth attached to the implant might crack or chip. In extremely rare cases, the implant itself (the titanium alloy bolt inserted into your jaw) can fracture, but this is generally only possible due to blunt force trauma caused by an accident.
Implant overloading is a concern during osseointegration, which is the most delicate part of the overall process. This can be avoided by strictly adhering to your aftercare instructions, which largely pertain to your diet—meaning you must be careful what you eat during osseointegration while taking care to only chew on the unaffected side of your mouth. Even if your implant has been fitted with a temporary prosthetic crown, this doesn't have the same functionality (ability to withstand bite pressure) as a natural tooth or the permanent crown that will be added post-osseointegration. However, some patients will continue to be at risk of implant overloading—even when the implant has completely healed.
Protecting Your Implant
Patients who grind their teeth (a condition called bruxism) can inadvertently cause implant overloading. During waking hours, it can be relatively simple to refrain from this behavior. However, the majority of your grinding may take place while you sleep, and you have little control over your actions—actions that can contribute to implant overloading. This is where that extra protection enters the picture. Your dentist might recommend a bite guard. This is a customized thermoplastic aligner that's worn over your teeth (usually only on your upper or lower dental arch) while you sleep, creating a barrier that prevents your teeth from grinding together.
A bite guard is a wonderfully simple solution and can be extremely effective at protecting your implant (as well as your other teeth). And in protecting your implant, you're also protecting your investment.