All on 6 Dental Implants in Vijayawada | A Case Study

People nowadays are opting for faster treatment times. Gone are the days when patients could wait three months to get their implants loaded. Due to the complexity of life and lifestyle changes, many are seeking fixed teeth within a week. Most of these patients are from abroad or planning to travel soon.

In such cases, the dentist should choose the most suitable option based on the patient's needs and comfort. The first and foremost option is the all-on-6 with pterygoids.

In this blog, I will discuss all-on-6 with pterygoids. I will present a case I did today as an example for clarity. This approach will help explain the procedure using a real case.

What is an All-on-6 with Pterygoids?

The all-on-6 with pterygoids is an advanced version of the all-on-6 procedure. It involves bicortical engagement, which is essential for predictable immediate loading. In this method, four implants engage the jawbone and the nasal floor (anterior implants). Two implants engage the jawbone and the pterygoid plate of the sphenoid bone. This bicortical nature allows the implants to achieve massive torque, often exceeding 70 Ncm. Therefore, immediate loading is possible, eliminating the need to wait three months after implant placement.

Please examine this X-ray of our patient to appreciate the nasal floor and pterygoid engagements.

Why Do Many Clinics Prefer Unicortical Engagement?

Unicortical engagement is simpler and less demanding for surgeons. It involves engaging the first cortical bone, known as the near cortical. The second cortical is referred to as the far cortical. Engaging the first cortical is easier as it requires smaller implants that remain entirely in the jawbone and do not engage the nasal floor.

In cases where there is no bone, especially in the posterior maxilla, many clinics claim that implants and fixed teeth are not possible. They often suggest removable dentures as the only option.

These clinics rarely attempt to engage the pterygoid bone when the posterior jawbone is lost. However, the pterygoid bone is dense and resistant to resorption. Pterygoid implants offer excellent long-term survival rates, as documented in recent studies, with a success rate exceeding 98 percent. Many dentists avoid engaging the second cortex, leading them to reject cases due to insufficient bone quantity or quality. They often suggest waiting three months for fixed teeth after placing implants.

Interestingly, 100 percent of practicing orthopedic surgeons use bicortical fixation as the standard for surgery. In contrast, only 10 percent of dentists adopt it as the standard for implant surgeries.

Why is Bicortical Engagement the Best Option for You?

The bone typically has two cortices: the first cortex (near cortex) and the second cortex (far cortex). The second cortical bone is dense and less susceptible to infection and resorption, making it a stable cortex.

Surgeons should prefer engaging this quality bone. The stable cortices significantly enhance the primary stability of an implant, making it eligible for immediate loading. Additionally, this approach dramatically increases the long-term success rate.

Orthopedic surgeons never overlook far cortical engagement. Numerous studies indicate that bicortical engagement in dental implants correlates with long-term success and stability.

At Your Dentist Dental Hospital, located in Vijayawada, Andhra Pradesh, we always utilize bicortical engagements in our daily practice of all-on-6 dental implants. Almost all cases we handle are loaded within a week, similar to practices in the United States or the United Kingdom. Developed countries predominantly use bicortical engagement for implant placement, ensuring patients receive teeth within a week.

Here are a few studies you can research further, published in reputable international journals:

1. Hsu et al., 2016: “Comparison of Initial Implant Stability of Implants Placed Using Bicortical Fixation, Indirect Sinus Elevation, and Unicortical Fixation.” This study supports the idea that bicortical fixation can improve initial stability and allow the use of longer implants.

   
   

2. Mantovani et al., 2018: “Influence of Cortical Bone Anchorage on the Primary Stability of Dental Implants.” This paper found that insertion torque values and ISQ were influenced by cortical bone contact, supporting the idea that cortical engagement improves primary stability.

   
   

3. Pałka et al., 2019: “Immediately Loaded Bicortical Implants Inserted in Fresh Extraction and Healed Sites…” This clinical study reported cumulative survival rates of 99.3% at 12 months, 98.6% at 24 months, and 97.0% at 35 months for immediately loaded bicortically anchored implants.

   
   

4. Di Stefano et al., 2021: “Stability of Dental Implants and Thickness of Cortical Bone: Clinical Research and Future Perspectives. A Systematic Review.”

   
   

5. Rues et al., 2021: “Effect of Bone Quality and Quantity on the Primary Stability of Dental Implants in a Simulated Bicortical Placement.” This study found that primary stability increased with higher bone mineral density and greater overall cortical bone thickness.

   
   

6. Javed & Romanos, 2010: “The Role of Primary Stability for Successful Immediate Loading of Dental Implants. A Literature Review.”

   
   

How Do Pterygoid Implants Provide a Biomechanical Advantage for All-on-6?

Pterygoid implants offer a significant biomechanical advantage for all-on-6 procedures. They allow for the placement of the most distal support much farther posteriorly, changing the force system of the entire prosthesis. Clinical reviews describe pterygoid implants as effective in avoiding cantilevers and improving biomechanical stability in the atrophic maxilla.

Here are the practical biomechanical advantages:

1. Increased Anteroposterior Spread: Placing the posterior implant in the pterygomaxillary region moves the terminal support distally. A wider A-P spread improves load distribution of the prosthesis, contributing to better outcomes in maxillary full-arch prostheses.

   
   

2. Reduced or Eliminated Distal Cantilever Length: This is a significant advantage. In standard upper full-mouth implants without posterior support, the molar region often becomes a cantilever. Cantilevers increase bending moments on distal implants, prosthetic screws, frameworks, and crestal bone. Literature notes that distal cantilevers can raise mechanical risk, while pterygoid implants help avoid these cantilevers.

   
   

3. Better Supported Arch: Without pterygoids, posterior occlusal forces act farther from the terminal implant, causing the framework to behave like a long lever arm. Pterygoid implants shift the point of posterior support backward, reducing torque on anterior implants and lessening stress concentration at the crestal bone of anterior implants.

   
   

4. Improved Posterior Occlusal Support: A maxillary full-arch performs better when posterior loading is carried by actual posterior fixtures rather than a long distal extension. This stability is especially beneficial during mastication, particularly for stronger biters or patients with broader arches.

   
   

5. Preservation of Favorable Force Pathway: The maxilla often has poorer bone quality, making long cantilevers less desirable. A systematic review found that in maxillary fixed prostheses, the all-on-6 implant group experienced less marginal bone loss than the all-on-4 implant group. Anteroposterior implant distribution is crucial for survival, supporting the notion that an all-on-6 benefits from both the number and placement of implants.

   
   

In summary, pterygoid implants enhance the biomechanical strength of an all-on-6 by providing posterior support, increasing A-P spread, reducing cantilever length, lowering bending moments on the framework and implants, and improving posterior load sharing.

All-on-6 Dental Implants in Vijayawada

Dr. Edara Surendranath is well-versed in placing pterygoid implants, boasting an almost 98 percent success rate. This expertise is why we at Your Dentist, led by Dr. Surendranath, confidently accept cases that others may reject due to insufficient bone.

Managing Angulations in Implants

We manage angulations using multi-unit abutments, which come in various angulations to counter the implant angulation and provide a stable, straight platform for prostheses.

At Your Dentist Dental Hospital, Dr. Surendranath and his team always use multi-unit abutments for every case, despite their higher cost compared to standard abutments.

Moreover, multi-unit abutments allow us to offer patients screw-retained teeth sets. Options include screw-retained DMLS, screw-retained zirconium, or screw-retained hybrid dentures. Any screw-retained option starts with a multi-unit abutment.