Explained by Oral & Maxillofacial Surgeon Dr Ali Direnç Ulaşan – Bursa, Turkey

If you have many missing teeth or very weak teeth and you are researching full-mouth implants, you will see terms like:

All-on-4

All-on-6

Full arch on implants

Angled implants or tilted implants

It is normal to feel confused and ask:

“What does All-on-4 actually mean?”

“What are these angled implants – are they safe?”

“When is All-on-4 enough, and when should I have more implants?”

As an oral & maxillofacial surgeon at Milim Dental in Bursa, Turkey,

Dr Ali Direnç Ulaşan plans and performs both All-on-4 and “more than four” (All-on-6 / All-on-X) treatments for local and international patients.

This article will explain in clear language:

What All-on-4 is and how angled implants work

Why tilting implants is often an advantage, not a problem

When All-on-4 is a good choice for a full arch

When we recommend more than 4 implants instead

How we decide which concept is most suitable for you

1. What Is All-on-4?

All-on-4 is a full-arch implant concept where:

4 dental implants are placed in one jaw (upper or lower)

A fixed bridge with usually 10–12 teeth is attached to these implants

Two implants are placed near the front (usually straight)

Two implants are placed further back and tilted (angled) to use available bone

The goal is to:

Give you fixed teeth (not removable like classic dentures)

Use a limited number of implants

Avoid big bone grafts in many cases

Often allow immediate loading (a fixed temporary bridge soon after surgery, in selected cases)

It is a smart way to rehabilitate patients who have:

Many missing teeth

Poor remaining teeth that must be extracted

Bone loss in the back of the jaws

A strong wish for fixed teeth as quickly as safely possible

2. What Are Angled (Tilted) Implants in All-on-4?

The phrase “angled implants” can sound worrying at first. Many patients think:

“A straight implant must be stronger… if it is tilted, won’t it be weaker?”

In reality, tilted implants are part of the design, not a mistake.

Why Do We Tilt Implants in All-on-4?

In the upper jaw, the back areas are often close to the maxillary sinus.

In the lower jaw, the back areas are close to the inferior alveolar nerve.

If we tried to place long, straight implants vertically in these areas:

We could touch the sinus or nerve (not acceptable)

Or we would have to use very short implants in shallow bone

Instead, in the All-on-4 concept, we:

Place the back implants at an angle, usually 30–45 degrees

Anchor them in better quality bone towards the front or side

Keep a safe distance from sinus and nerve

Support a long bridge using fewer implants

Imagine putting the legs of a table slightly angled outwards –

the table can be very stable if the angles are designed on purpose.

Are Angled Implants Weak or Unsafe?

When planned correctly by an implant team and placed by an experienced oral & maxillofacial surgeon like Dr Ali Direnç Ulaşan, angled implants:

Are not weaker than straight implants

Can actually increase the distance between front and back support (better distribution of chewing forces)

Help avoid extensive bone grafting or sinus lifting in many cases

The key is:

Proper 3D planning (CBCT scans, digital software)

Correct implant length, diameter and angulation

Correct design of the metal framework or zirconia bridge that connects the implants

Angled implants are a tool in advanced implantology – not a compromise.

3. When Is All-on-4 a Good Option?

All-on-4 is not a “magic solution for everyone”, but it is an excellent choice in many situations.

At Milim Dental Bursa, we often recommend All-on-4 (or a very similar 4-implant concept) when:

3.1 The Jaw Has Limited Posterior Bone

You have lost bone in the back part of the jaw (near molars)

There are sinuses (upper jaw) or nerves (lower jaw) close by

Bone grafting or sinus lifting would be possible but you prefer to avoid big surgeries

By tilting the back implants, we can:

Use the available front and side bone

Avoid grafts in many cases

Still place a full-length bridge from front to molar region

3.2 You Want Fixed Teeth with Fewer Implants

Some patients:

Are tired of removable dentures

Want fixed teeth but also want to limit cost and surgical complexity

All-on-4:

Uses 4 implants instead of 6–8

Can be more cost-effective

Can be completed in fewer surgical steps in suitable cases

3.3 You Are Edentulous or “Hopeless Dentition”

All-on-4 is ideal for:

Patients who already have no teeth in an arch

Patients whose remaining teeth are so damaged (decay, gum disease, fractures) that they must all be removed

In these cases, we can often:

Extract the remaining teeth

Place 4 implants

Fix a temporary bridge onto those implants (immediate loading), when stability and conditions allow

Later, after healing, this temporary bridge is replaced with a definitive zirconia or hybrid bridge.

3.4 You Need a Predictable, Efficient Treatment

All-on-4 has been studied for many years and, when done correctly, shows:

High success rates

Good long-term stability

Efficient use of available bone

For many full-arch cases, it is a well-balanced compromise between:

Biology (bone, gum health)

Mechanics (force distribution)

Cost and complexity

4. When Is It Better to Use More Than 4 Implants? (All-on-6 / All-on-X)

Now the other side of your question:

“When is All-on-4 enough, and when do we prefer more implants?”

At Milim Dental Bursa, we move towards All-on-6 or more in several situations.

4.1 Young Patients with Strong Chewing Forces

If you are relatively young

You have strong bone and a very powerful bite

Or you have a history of bruxism (teeth grinding / clenching)

then spreading the load over more implants can:

Reduce stress on each implant

Decrease the risk of mechanical complications (screw loosening, fractures)

Provide greater redundancy if one implant has a problem in the future

In these cases, All-on-6 or even more implants may be recommended, especially in the upper jaw.

4.2 Good Bone Volume and Quality

If CBCT shows that:

You have enough height and width of bone in several regions

There is space to safely place more implants without complicated grafting

then adding implants can give:

More stability for the bridge

Better support for long spans

Possible segmentation of the prosthesis for easier repair

There is no rule that says “4 is always best”.

In some jaws, 5, 6 or more implants provide a more comfortable margin of safety.

4.3 Very Long Arches and Large Chewing Surfaces

When we plan:

Full arch rehabilitation with posterior molars included

Wide arches with a large distance from left to right

having more than 4 implants may improve:

Distribution of forces

Support under the back teeth

Long-term function, especially for heavier patients or those who eat very hard foods

4.4 Combination with Zygomatic or Pterygoid Implants

In extremely resorbed upper jaws, we sometimes combine regular implants with:

Zygomatic implants (anchored in the cheekbone)

Or pterygoid implants (towards the back of the maxilla)

These advanced techniques naturally involve more than 4 total anchorage points, even though the philosophy is still “All-on-X” – a fixed full arch on a limited number of strategically placed implants.

This level of treatment absolutely requires an experienced oral & maxillofacial surgeon like Dr Ali Direnç Ulaşan and a clinic equipped with full 3D planning and surgical infrastructure.

5. All-on-4 vs More Implants: How Do We Decide for You?

There is no universal rule like “All-on-4 is always enough” or “All-on-6 is always better”.

At Milim Dental in Bursa, we make this decision individually using a structured approach.

5.1 Detailed Diagnosis

We start with:

Full medical and dental history

Examination of existing teeth, gums, bite, jaw joints

Panoramic X-ray and CBCT (3D scan)

We evaluate:

Bone volume (height, width, density) in each region

Sinus and nerve positions

Smile line and aesthetic demands

Space for prosthetic materials (zirconia, hybrid, etc.)

5.2 Risk Factors

We consider:

Age

Smoking

Diabetes and other systemic conditions

History of gum disease

Bruxism (night grinding)

More risk factors may push us to increase the number of implants and to design the prosthesis in a way that is easier to clean and maintain.

5.3 Your Expectations and Budget

We also listen to you:

Do you strongly prefer fixed teeth only, no removable options?

Are you okay with a semi-fixed overdenture if it is very stable?

What is your budget range?

Sometimes:

For one patient, the perfect compromise is a fixed All-on-4.

For another, it is safer and smarter to plan All-on-6.

For a third, health or finances indicate implant overdentures instead.

The important point is that the choice is not random; it is based on:

Anatomy

Biology

Mechanics

And your personal situation

6. Are More Implants Always Safer?

It might sound logical that:

“If 4 implants are good, 6 or 8 must always be better.”

But this is not always true. There is a balance.

Too many implants placed too close together in limited bone can:

Compromise blood supply between implants

Increase the risk of hygiene problems (too many small gaps to clean)

Make surgery and prosthetics more complex than necessary

All-on-4 is successful because:

The implants are placed in strategic positions

The distal implants are angled to maximise support

The prosthetic framework is designed to bridge these supports efficiently

The goal is not to place “as many implants as possible”, but to place the right number in the right positions, and then design a bridge that works harmoniously with your bone, muscles, joints and lifestyle.

7. Key Takeaways – All-on-4 and Angled Implants vs More Implants

Let’s summarise your original questions:

“What are angled implants in All-on-4?”

They are intentionally tilted implants at the back of the jaw.

They avoid sinuses and nerves by anchoring in better anterior or lateral bone.

When planned properly, they are strong and safe, not a compromise.

“When is All-on-4 enough?”

All-on-4 is often ideal when:

You have significant bone loss at the back of the jaws

You want fixed teeth with fewer implants and often fewer surgeries

You are edentulous or have hopeless teeth in one arch

You want an efficient, proven full-arch solution without extensive grafting

“When do we prefer more implants (All-on-6 / All-on-X)?”

We recommend more implants when:

You are young with strong chewing forces or bruxism

You have good bone volume that can safely accept extra implants

The arch is wide and we want even more support under back teeth

We are combining standard implants with zygomatic or pterygoid implants in extreme bone loss cases

8. What Should You Do If You Are Considering All-on-4 in Bursa or Turkey?

If you are thinking about:

All-on-4, All-on-6 or another full-arch implant concept

Fixed teeth instead of removable dentures

Getting treatment in Bursa, Turkey

the most important step is a full, honest evaluation.

At Milim Dental, oral & maxillofacial surgeon Dr Ali Direnç Ulaşan and the team will:

Analyse your bone and health in 3D

Explain All-on-4 vs more implants in your specific case

Show you what is possible for function and aesthetics

Help you choose a plan that is safe, realistic and long-term

So instead of trying to decide alone “Is All-on-4 enough for me, or do I need more implants?”, let a specialist team look at your jaws, your health and your expectations – and build a treatment plan made exactly for you.