Dental Implant Crown Dropped Out!

Dental Implant Crown Dropped Out!

Regardless if you have a cement or screw-retained dental implant crown, a common complication is that the crown may sometimes come off. So what should you do if your dental implant crown dropped out?

In the case of cemented crowns, the problem could be due to one of four possibilities. The first is the cementation of the crown onto the dental implant abutment. Under normal usage, the forces exerted on the implant crown during function may lead to failure of the cement layer. This layer holds the crown onto the implant abutment. Assuming that the dental abutment and crown have been designed correctly, the crown and the implant can be cleaned. The crown can then be recemented.

Sometimes the implant abutments are not designed with sufficient retenton and resistance form. This is usually is due to the walls of the implant abutments being too short or too tapered. The implant crown cannot securely grip the implant abutment.

In these instances, if the crown is recemented, it will just fall out again. The implant abutments need to be properly redesigned and remade. A new dental implant crown will also be needed.

Another possibility is that the implant abutment screw connecting the abutment to the implant fixture may break. If the screw fragment can be removed from the implant fixture, and the dental implant crown and the implant fixture are not damaged, a new implant abutment screw can be inserted, and the implant abutment securely bolted to the implant fixture.

The last possibility is that the dental implant crown split into two or more parts. In this situation, a new implant crown will need to be fabricated and delivered to the patient.

For screw-retained crowns, the failure can also take place at one of three points. Firstly, the implant abutment screw can fracture, leading to dislodgment of the dental implant crown. Similar as to with the cemented implant crowns, if the crown and the implant fixture are undamaged, the implant abutment screw can be replaced.

If a titanium base is used, it may debond from the implant crown. If the crown is intact, the crown and the titanium base can be cleaned and bonded together again. If the crown has damaged, it will need to be remade.

Lastly, the implant crown may have suffered a catastrophic fracture. A new implant crown would need to be fabricated and inserted.

If you are experiencing a problem with your implant crown, Contact Us to schedule an appointment to learn what treatment options are available to you.

Abutment Screw Fracture

Abutment Screw Fracture

The dental implant fixture is connected to the implant-retained crown or implant abutment with a retaining screw, know as the implant abutment screw. This is usually a titanium or stainless steel screw that is tightened to a particular torque value. This is known as the Preload or clamping force on the implant abutment screw.

After the dental implant and crown has been in function for a period of time, this retaining screw is subjected to vertical and lateral forces, that may result in the implant abutment screw loosening, or being damaged and breaking. If the implant abutment screw fractures, the implant crown will drop out.

When this happens, part of the implant abutment screw may be still embedded within the dental implant fixture. Sometimes this can be removed easily by turning the broken fragment with an explorer or ultrasonic scaler. If this does not work, most implant systems will have a screw removal kit that can be used to retrieve the fractured implant abutment screw that is custom designed for this purpose.

Fig. 1 Fractured Abutment screw in Implant Fixture.

Fig. 2 Implant Crown with Broken Abutment Screw

Fig. 3 Intact Abutment Screw

Fig. 4 Fractured Abutment Screw removed from Fixture

If the implant abutment screw can be removed without damaging the internal screw threads of the implant fixture, the dental implant crown can be reconnected to the implant fixture and a new implant abutment screw inserted and tightended to the appropriate preload.

However, if the screw threads are damaged, a replacement screw cannot be used. Some implant systems allow for the implant fixtured to be retapped, and a rescue implant abutment screw, which has a slightly larger diameter, can be used to secure the implant crown.

If such an option is not available, then a custom post can be fabricated, as is done with root canal treated teeth. This post is then cemented into the implant fixture, and a crown is cememnted onto it.

If this is not possible, the implant will need to be surgically removed. After a period of healing, a new dental implant fixture is inserted in the same position. Once fusion of the dental implant fixture to the jaw bone has occured, a new implant crown can be fabricated. This process usually takes 6-8 months to be completed.

If you are facing a similar issue with one of your dental implants, Contact Us for a comprehensive examination. We will assess your specific issue and inform you of the treatment options that are available to you.

Fig. 5 Cast Post Core in Implant Fixture

Implant Crown Chipped

Implant Crown Chipped

Imagine you are having lunch, you take a bite and your dental implant crown chipped! What do you do now?The good news is that you should not experience any sensitivity or pain as there are no nerves in the dental implant.

If the chip is relative minor, the sharp porcelain where the fracture occured can be trimmed down, either with a drill or a sand paper disc. This is a relatively quick and painless fix. You should be in and out of the dental office in no time at all.

If the porcelain fracture in your dental implant crown is larger, and you managed to retrieve the fractured ceramic, the fractured portion can be bonded back onto your crown. This is not the ideal option, but it can be done during the same dental visit.

The procedure can either be done in your mouth, without the need to remove the dental implant crown, or outside your mouth. The deciding factor would be how well the implant crown can be isolated to perform the bonding procedure.

The fractured porcelain is microetched, cleaned and conditioned. An adhesive bonding agent is then used to connect the two pieces of porcelain together.

If the implant crown chip is larger, or if you were not able to retain the fractured fragment, then things get a little more complicated. New porcelain can be added to your existing crown - if it can be removed without being damaged.

The restoration would need to be removed and sent to the dental laboratory. If you need to have a replacement tooth in that position, you would either have to use your old provisional crown or have a new one made.

Once the crown has been repaired, it is reconnected to the dental implants in your mouth.

The worst case scenario is the that chip is too large, or there has been a catastrophic fracture of the crown. In this situation, the broken crown  has to be removed and a new dental implant crown fabricated.

Please Contact Us if this is a situation you are dealing with and you need help resolving it.

Managing Dental Implant Angle

Managing Dental Implant Angle

Is your dental implant angle off? you facing challenges with dental implants that are not in an ideal position? 

Whether the dental implant angle was a deliberate decision to avoid bone grafting or a surgical oversight, we understand the need for a solution.

Our expertise lies in compensating for misangulated implants prosthetically, using specialized components.

By carefully considering factors such as angulation, position within the bone, and implant depth, we can devise a bespoke plan to rectify the situation.

In more severe cases where the misalignment is substantial, implant removal procedures may be necessary, followed by grafting and healing.

Once the site is ready, we can place a new implant in a more optimal position and restore it to ideal function and aesthetics.

If the malignment is mild, a cemented restoration can be used to restore the clinical portion of the tooth. A ceramic or metal post is connected to the dental implant with a retaining screw, then a crown is fabricated to fit this abutment. This is similar to crowns which are done on teeth.

Care has to be taken during the cementation to ensure that all the excess cement is removed, to prevent the extra cement from causing infection under the gums.

The main disadvantage of a cemented crown is retrievability of the crown. Occassionally, the crown may need to be removed for maintenance of the implant. Cemented crowns sometimes cannot be removed without breaking, and a new crown might need to be fabricated.

Specialized parts known as angled multiunit abutments can occassiuonally be used to redirect the direction of the implant retention screw.

These come in predetermined angulations, resulting in some limitations to how much correction can be made.

The extra parts increase prosthetic complications as well as the cost of restoring the implant.

A more innovative solution has been the development of dynamic axes screws, such as the Dynamic Abutment. These sophisticated screws allow for engagement at an offset of up to 25 degrees. In most cases, this is sufficient to redirect the access hole from the outer surface of the crown to the inner surface.

They not only do not require additional restorative space, but do not require additional components. The conventional abutment screw is exchanged for the dynamic axis screw.

These can be used either as part of a conventional analog work flow, or as part of a integrated digital CAD/CAM workflow.

The reduced number of parts and the larger implant retaining screw also decrease the incidence of prosthetic problems.

These revolutionary screws have significantly impacted how these cases can be managed, reducing the number of implants that have to be removed and lowering the costs of restoring these cases.



Something Broke!

Something Broke!

One complication can occur with dental implants is that something broke. Fracture of the dental implant or the implant restoration is not as uncommon as you may think. So what should you do if you encounter a breakage?

Firstly, we need to determine where the breakage occurred. The fracture could be at several different places. The dental implant (or fixture) could have fractured. Or the screw connecting the implant crown to the fixture could have broken. The implant crown could have split or the veneer porcelain of the implant crown could have chipped off.

The necessary treatment will depend on the location of the breakage. Simple solutions could range from simply smoothening out the porcelain surface, to changing the retaining screw. Should a catastrophic fracture of the fixture occurred, this would require surgical removal of the broken implant and possible replacement after a period of healing.

Should you be unfortunate enough to have encountered a breakage, do not hesitate to contact us! In addtion, any information you can provide us regarding your dental implant will be most relevant.

We will perform a comprehensive examination, complete with the relevant dental imaging. Finally, once we diagnose what your specific issue is, we will let you know exactly what your problem is and what needs to be done fix it.




Implant Fracture – Flange Fracture – Case Study

Implant Fracture – Flange Fracture – Case Study

Michael* presented at our clinic complaining that the dental implant crown on the lower right side of his mouth  was rotating. The implant had been placed and restored 4 years previously. Clincial examination revealed the presence of a screw retained crown on #46 that had rotated anti-clockwise, resulting in a gap between #46 and 45. We did not initially suspect an dental implant fracture.

Radiographic examination revealed the presence of a gap between the impant crown and the fixture platform. There was angular bone loss on either side of the implant, but was more pronounced on the mesial aspect of the fixture.

There also appeared to be a delamination of part of the implant below the mesial part of the fixture platform. We had not expected that the rotation of the crown was due to an implant fracture.

The screw-retained implant crown was removed and the fixture platform was exposed. There was complete fracture of about 40% of the lip of the fixture platform flange on the mesial part of the implant.

There was also a partial implant fracture of about 20% on the lingual aspect of the implant fixture. A flap was raised and the fractured portion of the flange was removed and the fixture was smoothened.

The flap was closed with a resorable suture and the screw-retained crown was then reconnected and the occlusion was adjusted to ensure there was no uneven occlusal contacts.

The abutment screw was tightened to the torque prescribed by the manufacturer and the access cavity was filled.

The patient was aware the implant fracture severely afftected the prognosis of the dental implant, and the dental implant would need to be removed if another implant fracture occurred.

*Not his real name.