Many of the buzz words you may have heard lately refer to the topic of implant dentistry: All-On-Four, Teeth In A Day, Permanent Tooth Replacement, and Immediate Tooth Replacement. Essentially, a dental implant is a device usually made of titanium, which is placed into your jawbone to permanently replace the root of a missing tooth. Once accomplished, the implant integrates or “fuses” to your bone and creates a firm foundation upon which a crown that actually looks and feels like a real tooth, is affixed. If you’re considering implants, you may have been told by your dentist that you need a sinus lift. It sounds pretty scary, right? In fact, it’s a very logical and straightforward process. But before I go into the details of a sinus lift, it’s important to understand a little bit about dental implants.
Many factors contribute to the success of an implant including, but not limited to, your general health, the overall health of your remaining teeth (if any remain), and the amount of bone you have. One truism in implant dentistry is this: You must have a sufficient amount of healthy bone in the first place to avoid implant failure. In order to support an implant during eating, and to ensure its long-term success, the volume and density of bone must be adequate.
A Sinus Lift Changes Everything
For decades, dentists were at a loss about what to do for patients who don’t have enough bone to support an implant. When a tooth falls out or is removed, bone loss around the remaining socket occurs at a very fast rate. And, if the missing teeth were lost due to periodontal/gum disease, then the volume of bone at the time of actual tooth loss was already reduced. According to The American Academy of Periodontology, “Undergoing sinus lift surgery has been shown to greatly increase your chances for successful implants that can last for years to come.”
Think of a dental implant as a fence post. Let’s say you want to build a strong, sturdy fence that will stand up to strong wind and wear and tear. You’re going to need to use a strong fence post. Moreover, the deeper you place your post into the ground and the firmness of the ground itself will determine the strength of your fence. It’s the same with dental implants. Placing an implant into weak bone is a recipe for failure.
Fortunately, new surgical techniques have evolved. When combined with advances in biotechnology and our greater understanding of wound healing, have yielded tremendous advancements in implant dentistry. Bone grafting today makes implant placement not only possible in patients previously thought untreatable, but it also makes long-term success highly predictable.
Sinus Lift Demystified
So back to the scary notion of a sinus lift. Let me take the mystery out of it for you. A sinus lift (clinically referred to as a sinus elevation and bone augmentation) is a procedure that has grown out of the latest thinking and research in implant dentistry. It makes it possible for people to get implants who until now were never candidates.
But first, what exactly are sinuses? Sinuses are air-filled sacks that surround your nasal cavity that work very hard for you. They filter and moisturize the air you breathe and because they are filled with air, they lighten the weight of the head, add resonance to your voice, and help protect your vital facial structures from trauma. They can also be a nuisance when inflamed or infected due to allergies or bacteria.
We all have four pairs of sinuses, the largest of which are the maxillary sinuses which are located near the orbit of the eye underneath your cheek and generally just above the roots of your upper premolars and molars. Sometimes the roots of these teeth sit within the sinus wall. That explains why sinus congestion sometimes feels like a toothache.
The maxillary sinus is very special to the implant surgeon because of its strategic location above your upper back teeth. That’s because when upper back teeth are missing, a significant amount of bone is usually lost. And if your upper back teeth are missing for a long period of time, not only will you lose more bone, but through a process called pneumatization, your sinus can expand into the area once occupied by the roots of your missing teeth. This leaves even less bone into which your dentist can place an implant.
Try to think of your maxillary sinus cavity as a cave. Now, imagine a balloon is inflated inside the cave to a point where the balloon and the rock walls touch. That is, in essence, what your maxillary sinus is. It’s an air sac or “balloon” that lies within the hollow boney walls of your sinus cavity.
A sinus lift “pushes” the bottom part of the balloon away from your bone and creates a space that your dentist can fill with bone tissue using bone grafting. This procedure ultimately creates enough bone that it can receive anywhere from one to several dental implants! Now you can see why sinus lifts have revolutionized implant dentistry.
Two Approaches to Performing a Sinus Lift
There are basically two approaches to executing a sinus lift, both of which I can perform right in my office if the need arises: the lateral wall approach and the crestal approach.
The lateral wall (also called lateral window) approach to sinus lift involves making an incision in your gum and lifting the tissue away from the underlying bone where the roots of your upper teeth once resided. A window is carefully prepared within your bone to reveal the underlying sinus membrane, which is then gently (very gently) teased away from the walls of your sinus cavity until sufficient space has been created for a bone graft. Your sinus proper is not entered but merely pushed away to create space for the graft.
Once grafted, the window is covered with a special collagen membrane that allows the window to heal with new boney encasement. Your gum is gently sutured back into place and your healing is monitored for six to twelve months, at which time your implants can be placed.
The crestal approach, on the other hand, allows for your sinus membrane to be lifted through the same site that will receive the dental implant and is done at the same time that your implant is placed. The crestal approach is much more conservative as it involves a very small incision and less bone and tissue manipulation than the lateral wall approach. And, since your implant is placed at the same time as the sinus lift, you’ll require only one surgical session instead of two.
The crestal approach that I use prepares your existing bone to receive an implant. Therefore, you must have enough bone present to stabilize the implant during the healing phase. During the crestal lift procedure, preparation of the implant involves exposing the sinus membrane at the top of the implant site. Hydraulic pressure using saline solution is used to tease the membrane up and free and bone graft material is placed within the implant preparation and pressed into the implant site (also called the osteotomy).
The crestal approach sinus lift procedure concludes with the placement of your implant At least six months healing and monitoring is required before the implants can be restored.
Sinus Lift in a Nutshell
Your upper jaw can provide your dentist with a reservoir of space that can be “filled” with bone graft to predictably create a substantial foundation for dental implants. This reservoir is called the maxillary sinus.
The two techniques under the “sinus lift umbrella” are the lateral wall approach and the crestal approach. The lateral wall approach is used when your dentist finds it necessary to generate an abundance of new bone to receive your implant.
The crestal approach is less invasive and requires shorter overall treatment and healing time. Although you’ll have to lay low for a little while on your gymnastics and down dogs, crestal is the preferred method when enough bone is already present for your implant to be placed on the same day. It’s not uncommon for my patients to go back to work on the same day as their sinus lift.
While every patient responds differently to surgical treatment, the potential for post-operative discomfort or pain is far greater with the lateral wall approach than with the crestal approach.
Which sinus lift approach is right for you? That will depend upon your anatomical and restorative needs. However, I believe that less is more and whenever possible, I’ll opt for the crestal approach.
The motto in my practice is: “Perform the least invasive procedure that will yield the desired result.”