April 6, 2023

This paid piece is sponsored by Siouxland Oral & Maxillofacial Surgery.

In February, we focused on an introduction to loading forces and how they can negatively affect dental implants. One way to compensate for the negative forces of overloading is to connect implants together or to simply have more implants. This is the scenario when replacing posterior teeth with dental implants.

Typically, people have first and second molars for chewing their food, also known as the 6-year and 12-year molars. When you lose these teeth, you start to chew your food with your front teeth and pre-molar teeth.

Unfortunately, these particular teeth are just not up to the task long term. In this scenario, the risk of fracturing the anterior teeth goes up. If you try to compensate by replacing these anterior teeth with implants, then the implants also will fail for the same reasons.

The posterior teeth protect the anterior teeth. Therefore, if you are missing posterior teeth, replacing them with dental implants will help protect the anterior teeth. Posterior bite forces are very strong and subject the implants to a lot of force. If you are missing both of your molars, it is best to restore the area with two or three implants depending on the amount of room available.

Ideally, we like to use three implants because we can offset the middle implant so that the three implants are not in a straight line but rather form a triangle. When you use the triangle configuration and connect the implants together, you make the implants more resistant to the lateral forces of chewing, clenching and grinding.

The downside to this approach is that it is a lot harder to clean around the dental implants, so you may have to see your hygienist three of four times a year instead of once or twice.

The way the lab designs the shape of the actual crowns also plays a role in how easy it is to clean around the implants. It’s a balance between being able to clean the prosthetic and around the implants and how the gum tissue adapts around the prosthetic crowns. Sometimes for posterior crowns on implants, we must accept that there will be a gap between the gum tissue and the crown so that the prosthetic has the proper form for cleaning.

We also often get the question of using two implants to replace three teeth like you would for a three-unit bridge on natural teeth to replace a single tooth. Can implants be used the same way? The answer is yes in limited scenarios because of the overloading problem. An implant bridge is an especially bad idea if the prosthetic goes around a curve. A good example would be to replace the canine tooth, the premolar behind it and the lateral incisor infant of it with two implants and a bridge.

Curved bridges in the mouth have the same problems that curved bridges for car traffic have. How many curved bridges for car traffic have you seen? Not elevated roads but true bridges — only a handful exist in the world. That gives you a sense of the engineering problems encountered and shared between real-life bridges and prosthetic bridges in your mouth.

We also strongly recommend that you ask your dentist to make you a night guard. If you do clench or grind at night, the night guard will redistribute the forces over many teeth or implants and decrease the destructive forces applied to any one area. It’s not a perfect solution, and some people still overload their implants, but a night guard helps the vast majority of people with dental implants. If you have dentures supported by implants, connecting them with a bar serves the same function as a night guard.

This is a nice segue into “teeth in a day.” The “teeth in a day” concept, also known as “all-on-four” or “all-on-x,” uses a temporary acrylic prosthetic to connect several implants together from one side of the mouth to the other, known as cross arch stabilization. This temporary prosthetic stays in place for six to nine months while everything heals and the implants bond to the bone. After that time period, the final prosthetic is made of stronger, more durable materials.

The TV ads make it sound like quite a simple thing, but truly it is not — especially if done correctly. There’s a lot of complex treatment planning, surgery, prosthetic fitting and diligence that goes into this form of treatment.

To learn more about Siouxland Oral & Maxillofacial Surgery, go to siouxlandoralsurgery.com.

Understanding dental implants can help find the best approach for you