Studies show that modifying the surface of dental implants using cold plasma just prior to implantation improves biomechanical fixation and bone formation. As a result, the use of plasma to modify the surface may reduce the loading time and overall success rate, especially in patients with well-known complications such as diabetes, osteoporosis, and heavy smokers.
What is a dental implant?
Dental implant surgery is a procedure performed by an oral surgeon (and recently also by periodontists and general dentists), in which a missing or damaged tooth is replaced by a titanium screw. The screw serves as the foundation for artificial teeth (or a denture), that look and function like real teeth.
The basis for modern dental implants is a discovery by a Swedish Physician, Dr. Per-Ingvar Brånemark is 1952, that while studying the relationship between blood circulation and the healing of bone tissue, was unable to remove the titanium housing of a microscopic lens he had placed in the leg of a rabbit. After finding that the bone had biologically fused to the metal casing, he soon realized the clinical potential of this surprising discovery: Titanium could serve as a bone-anchored foundation for dental prostheses.
Dr. Brånemark called the biological process “osseointegration – a direct connection between living bone and a load-carrying endosseous implant at the light microscopic level.” (More about osseointegration in dental implants below.)
Seventy years later, over 20 million implants are placed every year worldwide and according to the American Dental Association (ADA), more than 5 million implants are placed in the USA alone.
How do dental implants work?
The implant (titanium screw) is first placed in the Maxilla or Mandible jaw, so that it is likely to osseointegrate, and then a dental prosthetic (abutment and crown or denture) is added. A variable amount of healing time is required for osseointegration before the dental prosthetic is attached to the implant or an abutment is placed which will hold a dental prosthetic/crown.
The success of implants depends on the general health of the person receiving the treatment, drugs which affect the chances of osseointegration and the health of the tissues in the mouth. The amount of stress that will be put on the implant and final dental prosthetic during normal function is also important. The longterm success of osseointegrated dental implants depends on healthy bone and gingiva. While most implant companies claim an above 90%-95% success rate, the long-term success rate is normally in the range of 82%-85% and is dramatically lower for complicated cases such as smokers, diabetic patients and more.
Healing time for dental implants – loading
There are various options for when to attach teeth to dental implants, but in general this process, also known as “loading”, is either done immediately (immediate loading) or is delayed by about 3 months (delayed loading).
Research supports immediate loading with cold plasma
For an implant to become permanently stable, the body must grow bone on the surface of the implant (osseointegration). For many years the assumption was that loading an implant during the osseointegration period would result in movement that would damage the outcome, and thus increase implant failure rates. As a result, the guideline for loading was three to six months of integrating time before placing the abutment/crown on implants (final restoration). However, in recent years research suggests that the initial stability of the implant (how the implant grooves are attached to the existing bone) is just as important for implant integration as a 3-6 months’ healing time. As a result, more and more procedures now use immediate loading, and more patients are expecting to leave the dental clinic with “new teeth” and not wait for months with disturbing gaps of missing teeth in their mouth.
While this shift to immediate loading is a great solution for healthy patients, it may be a challenge for high-risk patients (smokers, diabetic patients) and a new solution is required.
Cold Plasma – surface modification & improved osseointegration
Osseointegration is a biological process; the interaction between the metal implant surface and the living body begins soon after the placement of the biomaterial in the body and it is a challenge to determine the optimal modification to accelerate the biological events which lead to faster osseointegration.
Cold plasma improves the dental implant surface
Cold Plasma is an excellent method to improve the implant surface, as it not only alters the surface charge, but it can also alter the chemistry of the surface. When cold plasma is applied to the implant surface, the reactive mix of electrons & ions activates the surface, make it clean from organic substances (i.e. carbon) and super hydrophilic. While this effect is short lasting (hours to days at most, applying it just prior to implantation may improve biomechanical fixation and bone formation.
Wettability (hydrophilic properties)
Research shows that cold plasma can enhance the wettability (hydrophilic properties) of titanium implants which are commonly used in dentistry and orthopedics. This is created not only by altering the surface energy of the implants but also by changing the chemistry of the implants with a high concentration of reactive species.
The hydrophilic properties are important for improved integration of the implant with the living bone (medically known as osseointegration) and can shorten patients’ healing time by up to 50%.
Osseointegration in dental implants
Osseointegration is defined as: “the formation of a direct interface between an implant and bone, without intervening soft tissue.”
In dental implants, this relates to bone grown right up to the implant surface without an intermediate soft tissue layer (see image 1 below).