Short dental implants are exactly what the name suggests they are — dental implants shorter than conventional implants. That is about the only attribute which differentiates them.
In general, dental implants shorter than 7mm in height are considered short dental implants, although varying definitions have been followed over different periods of time.
How do dental implants work?
A brief detour into how dental implants have been tested and used over the years is necessary at this point. Traditionally, the idea was to put in the biggest and widest possible dental implant in the available bone so that it would be strong enough to withstand chewing forces.
In areas where the bone height was considered insufficient, additional surgeries were performed to try and place a long implant. This increases the cost, time of treatment, and the invasiveness of the procedure for the patient — putting dental implants squarely out of reach for many.
Short implants are very versatile
Short implants can work in situations where conventional implants just do not fit. Areas where teeth used to be that have suffered a lot of bone loss can be rehabilitated with the use of short implants without performing any other additional surgery. This means no sinus lifts, no bone grafting, no nerve lateralization, and no other complex procedures to get dental implants.
Are short implants as strong as conventional implants?
This is where the controversy comes in. A few studies carried out on short dental implants early in the development of dental implant treatment protocols found them to last less long be more prone to failure as compared to longer implants.
Over the last few decades, though, that thinking has changed.
Short implants have been studied with better protocols and patient selection, leading to much better results in scientific studies. Data now indicates that short implants have a survival rate very similar to conventional implants (short and long term) and are able to perform the same function as other implants as well.
One of the golden rules of dentistry has been adhering to the crown:implant ratio while planning fixed replacements. This basically dictates that the roots cannot be overloaded with crowns or bridges to avoid failure.
This rule was followed for bridges where the teeth were providing the support and then adopted without change for dental implants. For short implants, this rule was being broken, something considered to oppose good dental practices.
The current view looks at crown:implant ratio a bit differently for dental implants, since shorter implants can be made wider to try and increase the total surface area in contact with the bone. Dental implants also have a different type of connection to the bone, one which some researchers believe leaves some room for flexibility when it comes to the crown:root ratio.
Biggest advantages of short implants
Do short dental implants come with any disadvantages?
There are definitely some limitations to the use of short dental implants and they must be considered carefully before treatment.
Almost all dental implants have been found to undergo a little bit of bone loss over the course of years. This can be as less as 0.5mm per year. In the case of conventional implants, there is a lot more bone to work with as compared to short dental implants. Even a little bit of bone loss in short dental implants can be associated with a lot more complications.
Case selection is also very important when it comes to providing treatment with short dental implants. People who have strong chewing forces are not good candidates for these implants.
More short dental implants need to be inserted into the jaw bone to try and support a big prosthesis. For patients, that may actually end up adding to the overall costs in some cases. The front areas of the jaw, where the amount of bone is compromised, sometimes needs bone regeneration surgery for proper support of the soft structures of the face and thus short dental implants don’t really serve a purpose there.