Tooth color Archwire

Anti-bacterial

No Peeling of the Coating

Non Toxic : Silver and Parylene

Half Anterior Coated Archwire

Silver Crystal

Reasons of Underdeveloped Market

Hydrophobic

Biocompatible : FDA approved for various medical applications

Guiding catheters, needles

ParyleneParylene is the trade name for a variety of chemical vapor deposited poly(p-xylylene) polymers used as moisture and dielectric barriers. Among them, Parylene C is the most popular due to its combination of barrier properties, cost, and other processing advantages. Parylene is green polymer chemistry. It is self-initiated (no initiator needed) and un-terminated (no termination group needed) with no solvent or catalyst required. The commonly used precursor, paracyclophane, yields 100% monomer above 550 °C in vacuum and the initiator and does not yield any by-products. That said there are alternative precursors to arrive at the parylene polymers that possess leaving groups as opposed to the cyclophane precursor. The most popular using bromine to yield the parylene AF-4 polymer. However, bromine is corrosive towards most metals and metal alloys and Viton O-rings so it is difficult to work with and precautions are needed

Reactive parylenesMost parylenes are passivation thin films or coatings. This means they protect the device or part from environmental stresses such as water, chemical attack, or applied field. This is an important property however many applications have the need to bond other materials to parylene, bond parylene to parylene, or even immobilize catalysts or enzymes to the parylene surface.

Characteristics and advantagesMost parylenes are passivation thin films or coatings. This means they protect the device or part from environmental stresses such as water, chemical attack, or applied field. This is an important property however many applications have the need to bond other materials to parylene, bond parylene to parylene, or even immobilize catalysts or enzymes to the parylene surface.

Reactive parylenesHydrophobic, chemically resistant coating with good barrier properties for inorganic and organic media, strong acids, caustic solutions, gases and water vapor Low leakage current and a low dielectric constant (average in-plane and out-of-plane: 2.67 parylene N and 2.5 parylene AF-4, SF, HT)A biostable, biocompatible coating; FDA approved for various applications Dense pinhole free, with thickness above 1.4 nmCoating without temperature load of the substrates as coating takes place at ambient temperature in the vacuum Highly corrosion resistant Completely homogeneous surface Stable to oxidation up to 350 °C (Parylene AF-4, SF, HT) Low intrinsic thin film stress due to its room temperature deposition Low coefficient of friction (AF-4, HT, SF) Very low permeability to gases

Typical applicationsParylene films have been used in various applications, includingHydrophobic coating (moisture barriers, e.g. for biomedical hoses) Barrier layers (e.g. for filter, diaphragms, valves) Microwave electronics Sensors in rough environment (e.g. automotive fuel/air sensors) Electronics for space travel and military Corrosion protection for metallic surfaces Reinforcement of micro-structures Protection of plastic, rubber, etc., from harmful environmental conditions Reduction of friction, e.g., for guiding catheters, acupuncture needles and microelectromechanical systems.