What Is Osseointegration?
Individuals may have heard the implant dentist use the word integration or fusion while discussing the options for using a dental implant to restore a missing tooth or teeth. The most crucial step in restoring or replacing a missing tooth or multiple teeth by implants is the osseointegrating ability of the dental implant to the underlying jaw bone. The science of osseointegration has not only widened the scope of treatment options for edentulous patients, but their consequences directly affect the general systemic health of the patient.
What Are the Current Concepts Surrounding Osseointegration?
In the last few decades, the dental profession, including general dentists and prosthodontists, has demonstrated different techniques and methods to compensate for tooth loss ranging from conventional crowns and bridges to removable or fixed partial dentures. However, an implant scores higher in terms of chewing efficiency and long-term restoration of oral health.
Osseointegration is considered successful when there is no movement between the implant and the bone it is in direct contact with. In other words, the implant is firmly anchored and has undergone stable fusion with the jawbone. While the term was originally used specifically for titanium metallic implants, the concept of osseointegration now extends to nearly all current and previously used biomaterials that can integrate with bone.
Recent evidence suggests that coated implants display more osteoinductive properties than uncoated implants, which demonstrate only more osteoconductive characteristics. Also, the coagulation-related proteins that attach predominantly to the titanium surface alongside the material's surface properties are shown to impact the regenerative process of the affected tissue.
What Is the Physiological Mechanism of Integration?
The main objective of developing recent biomaterials for any dental application is to improve the quality of osseointegration and considerably shorten the time needed to achieve integration. The designing of implants involves changes in the surface characteristics to obtain a good cellular response in the physiologic environment.
Incorporating osteoinductive elements more than osteoconductive elements is heralded by most implantologists as the best measure to achieve primary bone healing. Initially, blood is present only between the implant fixture and bone. However, then a blood clot forms. The blood clot is then transformed by phagocytic cells, such as polymorphonuclear leukocytes, lymphoid cells, macrophages, etc. Occlusal stresses also help stimulate the surrounding bone. As remodeling occurs, the osseointegrated fixtures can now withstand the tension of masticatory force or stress. The mechanism of osseointegration could be unpredictably affected by a pathological process that would not only cause inflammatory reactions in soft tissue (peri-mucositis) but subsequent bone loss around an osseointegrated implant (periimplantitis).
As a disease of the current era that correlates to long-term implant failure, peri-implantitis is defined as mainly a pathological condition characterized by clinical signs of inflammation such as bleeding on probing (BOP) with or without suppuration, an increase in peri-implant probing depths (PPD), and clinical attachment loss (CAL) that would be accomplished alongside radiographic bone loss with plaque accumulation.
In the three to six-month period of fusion between the implant and bone, the networks of collagen bundles surround the osteocyte cells and get inserted into glycoprotein layers. Research indicates that approximately a 100 Angstrom glycoprotein layer may be formed due to bone-implant contact. In addition, the Haversian bone also becomes well organized during this phase and forms osteon units.
What Is the Significance of an Implant Seal or Biologic Seal?
Current implant dentists have now recognized that for implants to be successful and survive for the long term in the otherwise hostile environment of the oral cavity, there has to be a productive biologic seal between the implant material and the jaw tissue or bone. Weinmann theorized the concept of a biological seal around implants.
More recently, Lavelle also emphasized the necessity for the attached gingiva to adapt to the integrated implant to provide a barrier against bacterial ingress and oral toxins into the space between implant posts and biologic tissues.
Dental implants are classified based on structure and bond contact. Whether endosteal, transosteal, or subperiosteal, they must still possess a superstructure or coronal portion, usually supported by a post.
This post must pass through the submucosal layer and the covering squamous epithelium into the gingival portion of the oral cavity. This is also known as the permucosal passage between the prosthetic part or attachment and the bony support of the implant.
This per mucosal zone is where initial tissue breaks down when the biological seal is affected. It begins as tissue breakdown and eventually causes tissue necrosis, which destroys the soft tissue or seals around the implant. The biological seal is vital in preventing peri-implantitis or implant infections, as it remains a pivotal factor in dental implant longevity.
A proper seal is a physiologic barrier that would be effective against the potential ingress of toxins, bacterial plaque, or oral debris. Still, it can also be protective against any other harmful substances that contact the implant in the oral cavity. Foreign body agents, known initiators of tissue and cell injury, must be prevented from entering the typical physiologic environment for bone stabilization. Only that can cause the implant to fuse successfully.
What Is the Purpose of Osseointegration in Dental Implant Procedures?
Osseointegration is essential for successful dental implant procedures. It provides the necessary stability for the implant to function like a natural tooth. Without this process, the implant would not integrate properly and lack the stability required for proper functioning.
Furthermore, a dental implant that has successfully undergone osseointegration helps maintain the health and integrity of the surrounding jawbone. Without natural tooth roots, the jawbone is prone to shrinkage over time, known as resorption. Dental implants replicate natural tooth roots, stimulating the jawbone and helping to prevent bone loss.
Conclusion
Hence, the knowledge or understanding of implant prosthesis has evolved over the last few decades from an experimental and laboratory-based field into an evidence-based clinical practice, for which the most crucial phenomenon of implant success remains "Osseointegration." Reaching out to specialists may be beneficial.