Patient Complaints & Problems with ALL ON 4 Dental Implants Singapore

Written by Dr Samintharaj Kumar


Millions of people globally have missing or have broken down teeth. One of the many different implant treatment options that they may have includes the “All On 4”. Prior to me returning to Singapore in 2013 this was not a common procedure. At current time in 2018, we are seeing more and more patients having this procedure done by their dentists.

The "All on 4" procedure was invented by Dr Paulo Malo in the 1990s in Portugal. Four to six implants are placed in the jaw bone to support an acrylic or zirconia bridge which predictably restores patient’s chewing function and smile. As per the MALO Protocol, the posterior implants are tilted to avoid anatomical features and thus may not need lengthy bone grafting or sinus lift procedures. Due to the safety profile published in the literature of a 98.2% success rate, it is widely accepted as the gold standard for full mouth implants.

The“All On 4” or “All On 6” is implant based full mouth reconstruction which requires teamwork and coordination with a high-quality dental laboratory that makes the final teeth for the patient. The original MALO Protocol has been published in the literature and is free domain knowledge. However this implant treatment is technique sensitive and the success of the treatment depends on proper initial treatment planning, the expertise of the treating dentists and cooperation between the surgeon, restoring dentist and the dental laboratory.

Along with the increasing popularity of the All on 4, patient complaints also have similarly increased.

Recently I examined a patient who came to me with an All on 4 bridge that had completely broken loose inside his mouth. A detailed examination showed that all the gold screws connecting the prosthesis to the denture had broken. Worse, one dental implant was clearly failing based on the x-ray. The All on 4 bridge was of poor quality and it lacked key design features as originally described by Dr Paulo Malo. As Director for MALO DENTAL Singapore, I have come across many similar patient complaints like lack of aesthetics, unpleasant smile, problems with chewing, bridge fracture and poor hygiene designs for All on 4 bridges, all of them leading to failures and patient dissatisfaction.

Problems with Poor Treatment Planning

Poor treatment planning prior to the surgery is a recipe for failure. Additionally, if the restorative dentist is not involved in the treatment planning or fails to spend the time needed for proper treatment planning or fail to communicate with the surgeon, implant placement can be compromised. These problems will negatively impact the restorative phase of the treatment and they are not easy to correct later in the treatment phase. Simply put, it is far much more difficult to treat a case after the case has been partially treated by another dentist. I remember another case of an elderly gentleman who had been to another country for treatment and was told he was going to get the All on 4 treatment done. When he woke after the general anaesthetic, he was told that the treatment could not be done but instead dental implants and bone grafts had been done. He rushed to MALO DENTAL in Singapore for an urgent opinion and was rehabilitated with a fixed bridge within 3 days of seeing me. This would have been avoided by proper treatment planning with CT scans and proper analysis.

The position of dental implants in this All on 4 procedure has a very important role on the All on 4 temporary bridge and final bridge durability. Cantilevers or unsupported teeth beyond the implants can break off due to excessive stress. Too much stress on the implants due to poor treatment planning can lead to bone loss and implant failures. These problems are worse in patients with a history of teeth grinding or bruxism. Proper treatment planning must be done to overcome the grinding forces of bruxism - which is a very challenging condition for any dentist to handle.

Problems with the All On 4 restorative process

Transitioning from a temporary All on 4 bridge to a final bridge is a highly technically demanding process with numerous stages. The restorative dentist must pay close attention to all the steps involved in this process and work with the dental lab at every stage. Should these steps not be followed through or insufficient patient trials are not completed, the final bridge may not be aesthetically and functionally adequate for the patient. Poor bridge design will lead to poor chewing, poor smile aesthetics and in many occasions a bridge that is too thick and makes it difficult to speak. At MALO DENTAL, for the final bridge, we frequently make another temporary bridge - this time with all the correct desired measurements and expectations. This transitional bridge is called the MALO DENTAL All Acrylic Bridge and the final bridge will be a replica of this should the patient be happy with this.

Poor Construction of All on 4 bridges

Every dentist knows that not all dental laboratories are same and the quality of the final All on 4 bridge is directly related to this. The restoring dentist must ensure that the bridge is constructed correctly with high-quality materials selected for the bridge. The design of the All on 4 bridge must avoid food collecting inside. Sharp edges and ledges must be avoided with the bridge being silky smooth to the touch of the tongue. Also, original implant parts and screws must be used to avoid mechanical failures of the bridge. Your All on 4 dentists must advise you to use a WaterPik daily. In addition to toothbrushing, the WaterPik is the secret as to how the All on 4 bridge can be kept clean. The design of the All on 4 bridge - regardless of whether it is temporary or not, must allow easy everyday cleaning. If it cannot be kept clean easily, the design of the bridge has to be altered.

Type of materials used for the construction of the All on 4 bridge

All patients must be aware of the limitations of materials and the costs related to All on 4 bridge construction. The final MALO All On 4 bridges are made with Acrylic or Zirconia, the choice may be made based on cost or clinical limitations. The Acrylic bridge tends to wear faster. However, the Zirconia or MALO Ceramic Bridge is a much harder wearing material and aesthetically superior. The Ceramic Bridges are stunningly thin compared to the Acrylic Bridge. However, the ceramic layer may chip or fracture, especially if the biting forces (occlusion) is not analysed and adjusted.

At MALO DENTAL Singapore we avoid using PMMA for the temporary bridge as PMMA is a porous material that is prone to stains. Stains can hoard bacteria.

Patient Expectations

Most of the ALL ON 4 patients would not have had full teeth for a long time. With the All on 4 procedure is done in a single day, this suddenly introduces a foreign object into the mouth that patient must get slowly adjusted to. There are some inherent problems with the implant-supported full arch denture that patient must be aware of. Natural teeth have nerves and it has proprioception which allows teeth to protect themselves from pressure and excessive forces. Dental implants do not have proprioception and thus they lack this protective mechanism. Hence any bite problems may be exacerbated leading to bridges chipping or failure. Patients are advised to eat slowly and carefully and thus develop a safe chewing pattern and chewing muscle memory with their new All on 4 teeth.

Remember that All on 4 bridge teeth do not come out of the gum-like natural teeth. The patient may feel that the new All on 4 bridge is bulky and that is always touching the cheek and tongue. There is an adjustment period and patient must slowly get used to the prosthesis in the mouth.

Caring for your All on 4 teeth

Routine care includes water flossing with a Waterpik and super floss to avoid food accumulation under the bridge. We stress that 4-6 month hygiene appointments to clean the gum around the implant areas is crucial to avoid dental implant failure. Some patients will be advised to wear a soft night guard to protect the bridge at night.

The gold screws supporting the bridge on the implants will work harden and fatigue over time. Patients are advised to go to the restoring dentist and remove the small gold screws and replace them with original new screws every few years.


At MALO DENTAL Singapore the All on 4 bridge is done on the same day as the Dental Implant Surgery. Same Day Teeth is what Dr Paulo Malo sought to achieve. This is the result which is expected at any MALO DENTAL globally.



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