When Your Sinus Gets in the Way of Successful Implant Placement

When Your Sinus Gets in the Way of Successful Dental Implant Placement

Successful placement of implants in the posterior maxilla could potentially be compromised by the lack of vertical dimension between the alveolar crest and the floor of the maxillary sinus. Typically, 10mm of vertical bone is required for predictable implant success (Misch 1987) although success can be achieved with less than 20 mm (Fugazzoto 2007). Moreover, bone density in the posterior maxilla is often poor, which could lead to complications during implant fixation. To address these problems, maxillary sinus elevation surgery was developed to increase the amount of bone available for implant placement.

Lateral Window Sinus Lift: A Sinus Augmentation Technique

Implant placement can be performed simultaneously with the sinus elevation procedure or following a healing period that can last

6-9 months. Immediate placement during sinus elevation reduces overall healing time and eliminates another surgical procedure, which can be desirable to patients. The decision to place an implant during sinus augmentation is dependent on the presence of adequate bone volume and quality to provide for initial stability of the implant. Rosen and colleagues (1999) recommended at least 5mm of native bone for immediate implant placement during sinus augmentation. However, more recent studies have found that implant stability can be achieved with less than 5mm (Peleg 2006).

Lateral Window Sinus Augmentation: The lateral approach involves a modified Caldwell-Luc operation to gain access to the sinus cavity. A bony window is created in the lateral maxillary wall, the Schneiderian membrane is elevated, and bone grafting material is a combination of autogenous bone and allograft. An absorbable collagen membrane is placed between the bone graft and the membrane as well as over the bony window.

This technique is usually the preferred method of sinus elevation in situations of poor bone quality and minimal residual bone height because it allows for direct visualization and accurate bone placement and volume at the position of the implant. Also, tearing of the membrane can be easily treated, minimizing contamination of the graft during healing.

For more information about Sinus Augmentation (Lift) procedures or Dental Implant Procedures, contact Joseph R. Nemeth, DDS and Associates at 248.357.3100 or via email at jodi@drnemeth.com. You may also want to visit the practice website at http://www.drnemeth.com.

Basic Principles of Michigan Dental Implants

Understanding the basic principles of Implant Dentistry can make your decision about whether or not a Dental Implant is right for you much simpler. A well informed patient will know how to ask the right questions and better make an informed decision.

General Considerations:

• An implant is a man-made replacement for a tooth root.


• Because of their very unique design, they become securely attached to the jawbone through a process called osseointegration.


• After a waiting period that allows the bone to heal around the implant, final restorations are screwed or cemented onto the implant or implant component.


• The final restoration is made utilizing procedures that are very similar to traditional crown and bridge dentistry.


• With Michigan Dental Implants, it is possible to replace a single tooth, multiple teeth, or an entire arch of teeth.


• For patients who are faced with losing all of their teeth, implant dentistry provides a tooth-replacement option that is much more stable and permanent than removable dentures or partials.

Implant Composition

• Implants are constructed from titanium.


• Titanium is a lightweight, soft, noncorroding metal.


• The surface of the titanium forms a natural ceramic coating when exposed to oxygen which enables bones cells to attach to it.


• Since bone cells react better to titanium surfaces that are rough, most implants are put through a roughening process by the manufacturer.


• To enhance bone healing, implants are sometimes coated with hydroxyapatite.


• Implants are often threaded. In order to enhance implant placement and stability, thread shape and pitch are carefully calculated to help transfer biting force to the surrounding bone.

Osseointegration

• Osseointegration describes the attachment of bone to the surface of an implant.


• Observation of an osseointegrated implant under a microscope reveals that bone attaches to the implant surface, but not in a continuous fashion. There are areas of direct contact separated by marrow spaces; therefore, only 40%-50% of the implant is in contact with bone.


• Surface treatment, such as a hydroxyapatite coating, work to increase the bone/implant contact.


• Under clinical observation, an osseointegrated implant will feel solid with no present mobility.


• When an implant fails to osseointegrate, slight mobility is noted. In such cases the bone surface is separated from the implant surface by a thin fibrous membrane which may be visible with careful x-ray analysis.


• A waiting period is required for successful osseointegration to occur because a complex series of events must occur.
  

For more information about Michigan Dental Implants visit the Joseph R. Nemeth, DDS & Associates website and submit your question online. The American Academy of Periodontology is also a helpful resource when deciding if you are a candidate for dental implants. Visit them on the web at http://www.perio.org/. Call (248) 357-3100 to schedule an appointment with our Dental Implant Specialist.

The Realities of Dental Implant Maintenance

Implant dentistry can effectively meet the restorative needs of both partially and fully edentulous patients. The five-year success rate is currrently in the 95 percent range for most implant cases. However, both the implants and the restorations they support can fail in response to local and systemic etiologic factors.

The ability to assess the reaction of the peri-implant tissues and to maintain their health is linked to improvements in the biology and mechanics that affect implant dentistry.

Implants are being fabricated from a variety of materials, and their surfaces are being modified to enhance integration . Furthermore, the restorative components are being revised to facilitate clinical procedures and to improve esthetics.

Traditional implant maintenance has in the past consisted of clinical assessment of placque control and radiographic evaluation of crestal bone levels. Additionally, it was important to determine the integrity of the connection of the prosthesis to the abutment to the implant body. However, the advent of single tooth and cemented restorations, early and immediate loading, the variety of abutment designs, and a shift in focus to more cosmetically-acceptable restorations has necessitated the development of changes in implant maintenance concepts.

To ensure the continued maintenance of optimum intraoral health, the dental team must understand how to assess the health of the peri-implant tissues, the alveolar bone housing, and the common restorative components associated with dental implants.

To learn more about dental implant maintenance, call 248.357.3100 or visit Dr. Joseph Nemeth & Associates on the web at http://www.drnemeth.com/.

Sinus Augmentation for Implant Planning in the Posterior Maxilla

Successful placement of implants in the posterior maxilla could potentially be compromised by the lack of vertical dimension between the alveolar crest and the floor of the maxillary sinus. Typically, 10 mm of vertical bone is required for predictable implant success (Misch, 1987) although success can be achieved with less than 10mm (Fugazzoto 2007). Moreover, bone density in the posterior maxilla is often poor, which could lead to complications during implant fixation. To address these problems, maxillary sinus elevation surgery was developed to increase the amount of bone available for implant placement.

Anatomy of the Maxillary Sinus

The maxillary sinus is pyramidal in shape and borders the nasal wall, floor of the orbit, and alveolar processes. The maxillary ostium, a non-physiologic drainage port, lies high on the medial wall and opens into the nasal cavity between the middle and lower nasal conchae. The average volume of a fully developed sinus is about 15ml, but the volume expands with age as the sinus pneumatizes. The sinus is lined with pseudostratified ciliated columnar epithelium that covers a loose, highly vascular, connective tissue. Beneath the connective tissue lies the periostium, which tightly approximates the bony wall. These structures - epithelium, connective tissue, and periosteum - are collectively referreced to as the Schneiderian membrane.

Indications and Contraindications for Sinus Augmentation

Prior to tooth loss, the sinus membrane maintains its position above the roots of the posterior maxillary teeth. Upon extraction, the sinus pneumatizes or expands unimpeded, reducing the over-all bone volume in the area. If less than 10mm of bone height remains after tooth loss, sinus augmentation should be considered to prevent implant placement from extending through the Schneiderian membrane. Contraindications may include uncontolled medical conditions, sinus pathology, acute or chronic sinusitis, heavy smoking, history of radiation therapy, and blood disorders. These patients may be at high risk of complication such as delayed wound healing or graft infection.

When used appropriately, sinus augmentation is an important tool for implant planning in the posterior maxilla. Predictable implant placement and restoration is possible for patients with minimal bone height, allowing for ideal treatment.

Interested in learning more about sinus augmentation? Contact the author of this article, Southfield Periodontist and Dental Implant Specialist, Dr. Amar Katranji at 248.357.3100 or visit Joseph R. Nemeth, DDS & Associates on the web at http://www.drnemeth.com/.

If you are a dentist and would like information about the Michigan Implant Study Club or any upcoming continuing education courses sponsored by Joseph R. Nemeth, DDS & Associates, visit the for dental professionals page of the website at http://www.drnemeth.com/forprofessionals.html.