The All-on-4 dental implantation method is an excellent option for patients who have lost teeth or whose teeth need to be removed due to root infection, trauma, or decay. This method is a good alternative to removable dentures and is suitable even when all teeth are missing.
Let us explain this technology in more detail and review a real patient case treated at YAREMA DENTAL clinic.
Yarema Miklosh, chief doctor, prosthodontist, gnathologist
What Are All-on-4 Dental Implants?
If all or several teeth need to be replaced, the All-on-4 implantation method is a suitable option. Instead of replacing each individual tooth with implants, only 4 implants per arch are placed. This provides a restoration that is not only functional and aesthetic, but also durable.
According to the scientific article “The Prosthodontic Concept of All-on-4 Dental Implants” published in PubMed Central, the All-on-4 method has shown very good results: after 5 years, 93% of patients maintain successful function, and the implants themselves integrate successfully in 98% of cases.
“All-on-4 is a system of 4 implants where the posterior implants are placed at an angle to reduce load and avoid complex surgeries. Success depends not on the angle, but on proper force distribution and minimization of leverage. The method has a high success rate but critically depends on technique and occlusion.”
These four implants are inserted into the jawbone, and a full-arch hybrid prosthesis is fabricated and attached to the four implant posts. This prosthesis cannot be removed unless a dentist uses special instruments during annual preventive check-ups.
This is an excellent solution for patients who have lost all their teeth, as well as for those whose teeth are deteriorating. It is important to remember that the procedure requires sufficient bone volume, so if there is a bone deficiency, treatment may need to begin with bone grafting. Scientific studies state that the recommended minimum bone width should be 5 mm, and the height at least 10 mm.
Advantages and Disadvantages of All-on-4
Advantages:
- quick implant placement;
- the ability to eat foods of any hardness, just like with natural teeth;
- the appearance of implants is indistinguishable from natural teeth;
- easy and convenient oral hygiene maintenance.
Disadvantages:
- temporary speech difficulties;
- residual pain and discomfort during healing;
- possible implant rejection, since not every implant may integrate into the gums and bone.
Patient’s Complaint and the Treatment Decision
Initial oral condition: worn prosthetic restorations and inflamed gums.
The patient complained about the poor condition of the front teeth, which caused psychological discomfort. The doctors assessed the condition of the gums, mucosa, bite, and bone using CBCT scanning.
They found that the area of the upper front teeth was in poor condition: the teeth were highly mobile, and there were old infections after root canal treatment. Therefore, the prognosis for preserving these teeth was poor.
The treatment plan included:
- extraction of 5 teeth (12, 11, 21, 22, 23);
- preparation of the bone and gums for implantation;
- implant placement;
- installation of a temporary prosthesis so that the patient would not experience psychological discomfort and could eat soft foods.
Why Was This Comprehensive Treatment Chosen?
This comprehensive protocol is possible only if the patient is in good general health, has satisfactory oral hygiene, and has no severe systemic contraindications such as uncontrolled diabetes, acute infections, uncontrolled bruxism, or serious immune deficiencies.
If such factors are present, the treatment protocol requires correction or postponement.
Clinical Indications and Contraindications
Indications:
- insufficient structure in the anterior part of the jaw for traditional restoration;
- damaged teeth with an unfavorable prognosis;
- high aesthetic demands (psychological discomfort caused by missing teeth);
- the possibility of achieving primary implant stability (dense multicortical bone and favorable anatomy);
- the presence of an adequate level of oral hygiene.
Contraindications:
- acute inflammatory conditions of the oral cavity;
- uncontrolled systemic diseases (diabetes mellitus, connective tissue diseases);
- severe periodontitis;
- the patient’s failure to comply with oral hygiene requirements and inability to follow recommendations;
- pronounced bruxism;
- lack of sufficient bone mass for implant stabilization.
Initial radiographic condition: multiple restorations, loss of bone support, and poor dental condition.
The patient had the necessary indications and no contraindications.
Stage 1. Preparation
First, the patient underwent professional dental cleaning and was instructed to discontinue anticoagulants where possible in agreement with the physician.
If necessary, pre- and postoperative antibiotics were prescribed, most often amoxicillin 1000 mg one hour before surgery.
Stage 2. Digital Planning
A CBCT scan confirmed sufficient bone volume. Then, the exact implant positions were digitally planned to ensure accurate placement according to the bite and to provide long-term function without overloading the bone.
Stage 3. Implant Selection
It was decided to place Straumann Bone Level Tapered (BLT) implants with a 4.1 mm diameter, but with different lengths depending on the tooth area:
- premolars — 4.1 × 14 mm, because there is more bone volume in this area;
- central incisors — slightly shorter implants 4.1 × 12 mm, because anatomically there is less available space there.
This choice was made because these implants:
- have a tapered shape, which provides better stability in the bone;
- have a special SLActive® surface, which helps them integrate faster and more reliably.
To connect the implants with the future prosthesis, standard RC abutments were used, which connect the dental implant to the prosthesis.
Stage 4. Tooth Extraction
Under sedation and local anesthesia, linear incisions were made to gain access; however, the tooth extractions were performed as atraumatically as possible.
The extraction sockets were thoroughly irrigated, cleaned, and prepared to ensure proper healing.
Stage 5. Implant Placement and Bone Grafting
The implants of the sizes mentioned above were then placed according to the pre-made surgical guide. The implants were inserted firmly and achieved strong primary stability in the bone immediately after placement.
At the same time, bone grafting was performed to restore and level the contour of the jawbone.
For this purpose, two types of grafting material were used:
- donor human bone;
- animal-derived bone.
To ensure proper integration and prevent displacement of the graft material, it was covered with a special protective membrane and fixed with small titanium pins.
Additionally, the contour of the bone near the front teeth was slightly corrected to avoid depressions or irregularities.
The soft tissue around the implants must be stable and sufficiently wide. To achieve this, either the patient’s own connective tissue from the palate (CTG) is grafted, or an artificial collagen material (CM) is used.
According to a study published on PubMed Central, the first option demonstrates better results.
The sequence of the procedure was as follows:
- tooth extraction;
- debridement (cleaning of the sockets, removal of infected/inflamed tissue and residual debris);
- implant placement;
- bone grafting;
- fixation;
- suturing of the gums.
Stage 6. Placement of the Temporary Prosthesis
One day after the surgery, a temporary prosthesis was placed: a titanium bar with an acrylic screw-retained provisional prosthesis attached to it.
The patient was advised to avoid chewing hard food with the front teeth and to follow a soft diet for the next 4–6 weeks.
After All-on-4 implantation: the implants have been placed and a bar-supported framework has been fixed for the full restoration of the dental arch.
Stage 7. Healing and Follow-Up
1 Week
After one week, the sutures were removed; the tissues appeared healthy and undamaged. There was slight swelling and mild discomfort, but this is an expected postoperative reaction.
The patient was reminded about gentle oral hygiene: rinsing with 0.12% chlorhexidine twice daily for 10 days to reduce the risk of infection. Analgesics were also recommended, as well as continuation of the antibiotic course.
1–2 Months
Evaluation of how the implants are integrating and how the temporary prosthesis is functioning. If necessary, it may be adjusted to ensure even load distribution.
3–6 Months
Clinical examination and assessment of tissue healing, as well as radiographic control. In case of stable osseointegration, final prosthetic rehabilitation is planned.
Since the temporary prosthesis was semi-removable, it may continue to be used until the fabrication of the permanent restoration, including a metal-ceramic or zirconia bar-supported construction.
Expected Results
After such a comprehensive protocol, a staged recovery is expected.
In the short-term perspective (up to 2 months), the prognosis is good if all instructions are properly followed: complete healing of the mucosa is expected, and successful integration of at least 3 out of 4 implants. Full integration of all implants is expected. Temporary minor complications may occur, such as swelling, bruising, and mild tissue sensitivity.
The combination of modern materials and technical craftsmanship makes it possible to create teeth that are impossible to distinguish from natural ones.
Within 3–6 months, the main goal is for the implants to firmly integrate into the bone and for the surrounding gums to become dense and healthy, allowing for placement of permanent teeth.
In the long-term perspective (2 years and more), the bone around the implants is expected to remain stable and not undergo significant resorption, provided proper care and regular dental check-ups are maintained.
As a result, the patient will receive strong front teeth that are almost indistinguishable from natural ones in both function and aesthetics.