Implant Dentistry Today No 14

Implant Dentistry Today 27 Allergies: Every day is more frequent to see patients with allergies especially non-noble metals. Of vital importance is to make a correct medical history of the patient. If the patient is allergic to one or both of these metals (Chromium or Nickel) a red and inflammatory area and pain will appear around the implants or in the buccal mucosa (32-37) . Another more important and debated point is the possibility that the non-noble metals may or may not compromise the patient’s health through a genetic mutation of the DNA or that they may increase the risk of suffering from some type of cancer. Here the literature, strictly dental, is not conclusive on this matter, but it is in other medical disciplines such as traumatology. In various articles (38-45) that refers to CoCr metal-to-metal hip prostheses, they speak of the possibility of changes in the patient’s DNA and with a cancer risk due to friction wear of the prosthesis. In the mouth, in the framework of the prosthesis, this wear of the metal is not so evident, but there is always a risk that we could avoid if we did not use this type of non-noble metal. Biomechanical behavior The third point to comment on is the biomechanical behavior of non-noble metals and zirconia. They have totally linear behavior, that is, without any type of bending or absorption of the functional or parafunctional forces applied by the patient. This rigid, hard, linear behavior... according to numerous articles, is the reason why there is an increase in periimplantitis in our patients since these materials produce an increase in stress in the implant-bone prosthesis area (46-50) . In other words: the functional forces (chewing, swallowing) and the parafunctional ones (clenching and eccentric bruxing) are transmitted to the implant-bone zone in all their magnitude, without any kind of damping. We know from the literature (51-56) that the sum of the forces applied plus gingival inflammation produces a peri-implant bone loss. Therefore, the use of such hard and rigid non-noble materials increases the risk of periimplantitis in those patients at risk of gingival inflammation: genetics, poor hygiene, smokers, previous periodontitis... (54,57,58) by transmitting more functional and parafunctional occlusal forces. Titanium or the different titanium alloys for dental use give us a very low rate of corrosion and a less linear behavior than non-noble metals, but not as the new composite materials. The linear behavior of non-noble metals or zirconia is the opposite of “new” or not so new composite materials (polymer) that have appeared in recent years for dental use. These materials are widely used in the aerospace-aeronautics industry, automobiles... but not very much used in medicine and dentistry. completely mask that black color of the fiber. The fiberglass can also be used with milling disks. In this case, we can drill it in a monolithic prosthesis (colors by Vita guide), and then it can be stained with resin. Another option is to cover it by resin teeth, composite, hybrid composites, or lithium disilicate ceramic crowns. The last material to arrive at our laboratories for dental use is the quartz fiber Daicom Quartz Fiber, in filaments for use by muffle. In this case, the best option is to use it with a compacted composite covering, which provides us with a very functional, durable, aesthetic, and economical prosthesis. For a removable prosthesis over teeth Peek framework and resin teeth (Dr Raul Medina- Galvez,Technos Dental Laboratory) Carbon fiber framework (milled) and lithium disilicate crowns cemented over it. (Dr. Oriol Canto-Naves,Technos Dental Laboratory) They are biocompatible materials, durable, resistant, and with physical characteristics that provide us with this damping-absorption of the functional- parafunctional forces (50,59-77) that reduce the risk of periimplantitis, as they transfer less of the forces applied, especially in these high-risk patients. These materials are PEEK, carbon fiber, glass fiber, and quartz fiber. In all three materials, the connection to the implants or the conical titanium transepithelial must be made by using a titanium abutment, thus avoiding any use of non-noble metal, thus avoiding possible corrosion and allergies/genetic mutations. PEEK, probably, is the most common polymer used in medicine and dentistry. We can work with it milling a disc or pressing small blocs and covering it with resin teeth or cementing lithium disilicate or zirconia crowns. This material has a problem of cementation. Different articles show it (78-83) . Carbon fiber can be found in monofilaments for use in muffles, in tablets for injection, or most common nowadays, in discs for milling. This material can be coated with resin teeth, composite, hybrid composites, and lithium disilicate ceramics crowns. The black color of the carbon fiber does not suppose any aesthetic problem since the commercial company (Daicom. Ruthiunium Group. Italy) provides us with a white and pink opacifier kit to Glass fiber framework and resin teeth. (Dr. Santiago Fernández) Glass fiber and Carbon Fiber discs. Framework (monolithic) make with Glass Fiber.