Saturday, April 18, 2009
Dental Implants in the Smile Zone- Keys for Success
Loss of a front tooth, whether due to an accident or decay, can be a very traumatic experience for a person. Dental implant is a great treatment option for replacement. However the front teeth and the surrounding smile zone present unique challenges that make therapy in this area amongst the most difficult to do. It requires the most expertise in both diagnostic and technical protocols. Here are the 5 key principles every patient should know, on how to achieve great results with Dental Implants in the Smile Zone.
Historically, patients had either a bridge or denture to replace their missing teeth. While a bridge offered satisfactory aesthetic results, it was too invasive and damaging to adjacent teeth due to the required preparation or ‘cutting down’. And a denture was aesthetically unpleasing, and difficult to wear and chew with; and often resulted in further damages to other teeth and supporting bone.
Dental implants have 98% + success rate, and are now the mainstay in teeth replacement therapy. But the aesthetic zone in the upper front area presents unique challenges which must be carefully addressed by the clinicians for optimal results.
Here is the problem: Loss of a tooth results in significant shrinkage of bone and overlying gum tissue in the region of the front incisors and canines. Also there can be additional remodeling and shrinkage after implant placement or grafting procedures . All of this, if not addressed, will result in an uneven gum line, poor aesthetics, difficult cleansing, and even failure of the implant in the long run. So here are the 5 key principles in achieving a result that you will love:
1) ‘Fail to Plan’; ‘Plan to Fail’
During the Initial Diagnosis and Planning, both the surgeon and the restorative dentist must collaborate closely and evaluate the following: Bone and Gum tissue level and thickness; Periodontal health; Smile line; and the position of other teeth. This requires x-rays or other imaging techniques, detailed examination, and study models which are all vital to a proper diagnosis. Study models can further be used for simulation of the final crowns, fabrication of a temporary prosthesis for the patient and making a special guide aiding the surgeon during implant placement. The surgeon and the restorative dentist, each with expertise in their field, should then review the gathered information and design a collaborative detailed plan to achieve a patient’s realistic goals. This plan, along with impending challenges, possible solutions, and associated risk factors should be throughly be discussed with the patient. Team communication is vital to executing the plan and ultimate success.
2) Preserve the foundation
Extraction of a tooth consistently results in loss of bone and the overlying gum tissue . This can easily be prevented by making sure that the surgeon grafts the site at the time of the extraction. Preserving the bone also maintains the overlying gum tissue, therefore creating a healthy foundation for the implant and its crown. The graft materials most often used for this type of procedure are calcified granules supplied in individual containers and it is rarely necessary to obtain it from the patient in form of actual bone. These materials promote bone healing in an extraction socket and minimize its shrinkage. Another way to preserve the foundation is placement of the implant at time of the extraction. This is known as ‘immediate implant’ and can be done predictably in appropriate sites. Finally, the temporary prosthesis, whether removable like a flipper or fixed like a bonded temporary crown, needs to be carefully shaped to guide the gum tissue during its healing.
3)Precise positioning of the implant by surgeon
With a healthy foundation, the surgeon can now place the dental implant. But it is most crucial that the implant is positioned properly in all dimensions including Height, width, and depth, and angulation. A poorly positioned implant is grounds for disaster and results in poor aesthetics and function. A simple rule is “To Never Place an Implant in Wrong Position”. This is accomplished by using a surgical guide made on study models or by using Cat scan generated computer planning. While the actual placement of a dental implant is simple, safe positioning and handling of the supporting tissue can be complex and should be performed by an experienced and skilled clinician.
4) Shaping the gum tissue
During the implant healing, the gum tissue architecture is further designed by placement of a temporary crown on the implant. This is one of the most crucial steps and is often overlooked or rushed. It is the only way to create the desired gum tissue level and shape as well as providing a patient a ‘glance’ of what the final crown will look like. In some situations and if appropriate, an immediate temporary crown may be placed on the same day as the implant. Otherwise it maybe placed several weeks later. Either way, the temporary crown should be left in place for 3-4 months to ‘design’ the proper gum tissue architecture as well as give patient the opportunity to provide feedback on its appearance and comfort.
5) Final Crown
The temporary crown provides a lot information that can be used to make the final crown look more natural, comfortable, and pleasing to the patient. Depending on the smile line, gum tissue thickness, and its shape, the restorative dentist may decide to use metal or ceramic extensions to support the final crown. Known as abutments, these extensions must have proper contour to create a natural and healthy gum line and crown. In the smile zone, it is crucial to use customized abutments that are fabricated in a laboratory, and not use ‘off-the-shelf’ abutments which are reshaped chair side by the restorative dentist. It is the use of customized abutments that allow optimal gum tissue architecture, aesthetics, and crown fit. The final crown itself may be made of either porcelain with underlying metal or completely out of ceramic material. This decision must be made by the restorative dentist based on aesthetic requirements of that specific patient. Finally it is important to use a quality laboratory and technicians who understand the demands of implants in the aesthetic zone and can work closely with the restorative dentist to make high quality crowns.
Losing a front tooth is a devastating experience for most people altering their self image, confidence, and social interactions. Dental implants offer a great solution for replacement however must be performed carefully by clinicians who have in-depth understanding of its challenges, biology, and the strict protocols required for optimal success.
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