What Is the Use of Metal in Dentistry?
Over the last decade, after extensive medical research by medical researchers and scientists, there has been growing awareness of metal allergies or the impact of metals on human beings. This extends to the specific field of dental medicine as well because this ranges from the use of porcelain fused metal or metal elements for crowns and bridges to the Ni-ti wires (nickel-titanium wires) in ortho field, metalized for functional appliances in pediatric and orthodontic fields, titanium and its alloys used in general dentistry as well as in the manufacturing of dental implants.
In all these applications, perhaps the most direct contact of metal with the bone occurs in the implant dentistry field because the titanium of the dental implant body or threads fuses with the underlying jaw bone, establishing bone-implant contact (BIC) and achieving primary stability through this fusion. In three to six months after placement of implants known as osseointegration. Research authors of some case reports have highlighted that dental titanium implants or surgical drills used by the implant dentist can release metallic particles into the jaw, causing allergies or type 4 hypersensitivity in predisposed or sensitized individuals.
This article aims to examine the latest research findings concerning the impact of direct metallic contact on bone health. Specifically, it will address the potential risks and safety issues associated with the release of titanium particles or titanium-based implant materials into the jawbone during the process of osseointegration.
What Are the Research Findings From Radiographic Imaging?
According to current implant dentistry research, extremely limited case reports are either documented or available regarding any form of hypersensitivity caused by titanium alloys or the release of titanium-containing material into the jaw bone. Nevertheless, due to the limited scientific research evidence currently available, researchers in the fields of dental implants and oral pathology have explored the reasons behind the lack of universal biocompatibility of dental implant materials. Though titanium dental implants are indeed the current gold standards that have the highest outcomes or success rates concerning osseointegration or BIC (bone-implant contact), few case reports state that the metallic artifacts in MRI (magnetic resonance imaging) possibly originating from titanium implants in the patients bone signifies that a mild foreign body reaction is possible with titanium implants. These metallic artifacts surrounding the dental implants were not detected either in OPG (orthopantomography)- 2-dimensional panoramic imaging or even through the advanced radiographic modality of present-day 3D cone beam computed tomography (CBCT), but have been observed and studied in very few case reports through the magnetic resonance imaging of patients jaw bone. According to present-day, dental implant updation and literature evidence, there would be a possible release of small particles that are of the metallic titanium that may interact with the jaw bone. Though this foreign body reaction is extremely discrete and unobserved in even 3D software such as CBCT, researchers state that just like other dental materials or alloys, titanium has its drawbacks as well, though it is the cornerstone of implant dental materials. In implant manufacturing, titanium alloys are much more preferred than pure titanium owing to their higher mechanical and physical strength properties.
Can Metal Allergies Be Possible in Some Individuals?
The possible current hypothesis from the imaging findings is that the surgical drills used in dental implants for the osteotomy preparation in jaw bones from the placement of the dental implant itself prepared from titanium or its alloys- show the release of small metallic particles that would probably result in post-operative pain or sensitivity In few patients. These metal particles then can cross-react or combine with endogenous molecules of protein In the jaw to form antigenic molecules in turn. In individuals with a history of foreign body reactions, with a history of certain food sensitivity or allergy reactions, with a history of metal allergy or specifically titanium allergies, or in individuals with autoimmune diseases like rheumatoid arthritis, a type 4 delayed hypersensitivity reaction of allergy can be possible, with such metallic interactions in the jaw, however minor or limited it may be. The langerhans cells that are part of the T-lymphocyte chain can be responsible for causing possible titanium-based hypersensitivity reactions- initiating inflammatory T cells, macrophages, cytokines, etc, in such individuals who are more predisposed to metal allergies.
Are the Risks Low With Titanium?
The potential risks associated with titanium and its alloys, while still under investigation, appear to be relatively minimal based on current dental studies. Nonetheless, the existing scientific data regarding the release of metal debris or particles from implant drills or the implants themselves is limited. Instances of metallic artifacts observed in certain MRI scans indicate that titanium cannot be considered entirely "risk-free." Additionally, there may be an increased likelihood of allergic reactions in individuals with a medical history of autoimmune disorders or metal allergies. Many current-day research studies are hence focused on innovating new materials for dental implants, reducing the risk of metal exposure to the jaw bone directly, avoiding overheating of surgical implant drills and the jaw bone- to prevent the detrimental released metal interaction with the bone.
Conclusion:
Dental research confirms that in most healthy individuals or without any immunocompromised systemic behavior, dental implants that are titanium-based are the gold standard treatment options with no negative repercussions or any risk of allergies. However, in predisposed individuals to metal allergies or those with autoimmune diseases, preoperative and postoperative evaluation of dental implants should be performed ideally by the implant dentist or the maxillofacial surgeon- to ensure that there are no post-operative risks like severe pain, allergies, or hypersensitivity leading to implant tissue inflammation and failure.
In a few case reports, the evidence of the interaction between titanium metal particles being released into the jaw bone shows that it is not a fully biocompatible material, which means that there is scope for exploring future alternatives to titanium and its alloys for manufacturing dental implants and overcoming these limited drawbacks.
