Ozone Use in Dentistry

By Dr. Alison Adams, Contributor

Ozone is an energised form of oxygen consisting of three oxygen atoms (triatomic oxygen or trioxygen) which occurs naturally in the atmosphere in response to sunlight and the action of lightening in storms. In fact, the presence of the ozone layer high in our atmosphere makes life possible on earth by filtering out the sun’s harmful ultraviolet rays and also accounts for why the sky appears to be blue.

Ozone was first identified in 1840 by the German-Swiss Christian Schönbein who named the substance after the Greek word ‘ozein’ meaning to smell.

The therapeutic use of gaseous ozone or ozone dissolved in either water or oil has been used in medicine and particularly natural medicine to treat various diseases for over 100 years throughout the world. For example, ozone gas was used during World War I to treat infected wounds, gangrene, mustard gas burns and fistulas in German soldiers.

Ozonated water was first used in dentistry by the Swiss Dr E. A. Fisch who used it to promote wound healing and aid disinfection in his practice in the 1930s. It was then introduced more widely to the medical community by the Austrian Dr. E. Payr and is still particularly favored in mainland Europe as a non-invasive, safe and versatile bio-oxidative treatment.

The effects of ozone therapy

Ozone works by creating a ‘transient oxidative burst’ in living systems which causes any microorganisms present to become stressed and die. However, whilst this oxidative burst has a cytotoxic effect on the microflora, it induces a multitude of the body’s natural biochemical and physiologic reactions. These reactions include:

• The activation of cellular metabolism and in particular that of red blood cells (RBCs) promoting oxygenation of the tissue and bone, and fibroblast metabolism inducing bone and tissue repair
• The modulation of the immune response through the release of cytokines which promote cell-to-cell communication
• The induction of antioxidant activity and reduction in inflammation
• Antimicrobial actions against bacteria, viruses and fungi
• Induction of the synthesis of carbohydrates, proteins and lipids and
• Some analgesic effect.

The medical applications of ozone include immune deficiency diseases including cancer, peripheral and cerebral arterial circulatory disorders, inflammatory diseases including arthritis, and the effects of ageing.

Although prolonged inhalation of gaseous ozone can have adverse effects on the lungs and other organs, in carefully controlled doses it appears to be safe with no side-effects or allergic reactions. However, the European Cooperation of Medical Ozone Societies warns that direct intravenous injections of ozone or oxygen gas should not be used due to the possible risk of air embolism. And the use of ozone is contraindicated during pregnancy, in severe anaemia, hyperthyroidism, after a recent heart attack, haemorrhage from any organ and in some other fairly rare disorders.

Ozone is now being increasingly used in dentistry and the main applications are listed below. The equipment involved is fairly portable and the appeal for patients is that it is non-invasive and so is highly acceptable to those who dislike or are anxious about drilling and particularly children. Ozone has been shown to be biocompatible with oral tissues and the International Academy of Oral medicine and Toxicology (IAOMT) recently reviewed the use of oxygen and/or ozone therapy in dentistry and approved it as being scientifically valid.

Ozone use in the management of tooth decay

Gaseous or aqueous ozone is used in dentistry as an antimicrobial agent which is effective against bacteria, fungi, protozoa, and viruses. In particular ozone disrupts decay forming (cariogenic) bacteria by converting the pyruvic acid formed into acetic acid which is not only not caries forming, but actually contributes to remineralisation of early decay as it buffers the fluids in plaque. In the laboratory 99.9% of caries forming bacteria were dead after a 60 second exposure to ozone.

In this manner, the use of gaseous ozone both arrests the progression of cavities, and promotes remineralisation of the tooth. However, decay that has not yet produced a cavity has been shown to be more likely to reverse than a cavitated lesion. Longer applications are required to penetrate the deeper cavities killing the cariogenic microorganisms involved in the dentine. Initial studies have also shown that ozone is capable of clinically reversing leathery root decay.

There is also good evidence to support the prophylactic use of ozone in restorative dentistry to sterilise the region prior to etching and the placement of either dental sealants or restorations.

Ozone use in the management of hypersensitivity

Sensitive teeth are a big issue and gaseous ozone has been shown to help reduce both tooth sensitivity and post-dental treatment pain. Typically, a deposit known as the smear layer forms over the exposed root surface which prevents calcium and fluoride ions penetrating the dentinal tubules. The application of ozone removes this smear layer allowing these ions to penetrate the tubular structure of the dentine thus preventing the fluid exchanges which give rise to the pain of sensitive teeth.

Ozone therapy in endodontics

Some dentists and endodontists use ozone gas, ozonated water and/or ozonated oil in an attempt to sterilise the root canal system after preparation and prior to completing a root filling. However, there is evidence that even if this were to be successful, the tooth rapidly become re-infected. See Problems with Root Canal Fillings for more.

The antibacterial and anti-inflammatory effects of ozone

Ozonated water is effective in killing some of the microorganisms in plaque including the bacteria and yeasts such as Candida albicans which contribute to causing periodontal disease. Although ozonated water has nearly the same antimicrobial activity as 2.5% sodium hypochlorite (bleach) it is less cytotoxic than either gaseous ozone or the other established antimicrobials such as chlorhexidine digluconate (Corsodyl), sodium hypochlorite or hydrogen peroxide.

By using the different forms of ozone such as ozonised water and oils, and placing ozone directly into infected gum pockets, periodontal disease can be arrested without recourse to pharmaceutical drugs with their associated side-effects.

In a similar manner, gaseous ozone and ozonated water can also be used to reduce the inflammation which can form around dental implants (periimplantitis) by promoting healing due to increased tissue circulation.

Ozone therapy in oral and maxillofacial surgery

Ozone therapy has been shown to promote wound healing and especially the healing of bone. Osteomyelitis can be particularly resistant to various interventions and this is particularly true of infections of the mandible because this area often has a poor circulation.

Ozone therapy has been used alongside antibiotics, surgery and hyperbaric oxygen in the treatment of refractory osteomyelitis of the jaw and as a preventive measure in patients undergoing radiotherapy to the head and neck. It has also been used in the management of surgical or extraction sites in patients treated with bisphosphonates for osteoporosis and appears to stimulate cell proliferation and soft tissue healing.

Ozone can also be used after routine tooth extraction(s) to promote proper healing and prevent the formation of cavitations. And the use of ozonated water by the patient has been shown to help speed oral healing and to decrease the need for painkillers and antibiotics post-extraction. Ozone has also been used to arrest dental abscesses and to treat the areas of necrotic bone that can form after an extraction that are known as jaw cavitations.

Other dental uses of ozone

Other uses of ozone in dentistry include:

• Decontamination of teeth that have been knocked out prior to their reimplantation
• The use of gaseous ozone in clinical settings to disinfect removable prostheses and the use of ozonated water at home to clean dentures
• The use of ozone to reduce (but not eliminate) the number of viable microorganisms which develop in the biofilm that forms in dental equipment tubing and
• Tooth whitening.

Whilst ozone forms a welcome addition to the dental treatment options available, its use in the treatment of gum disease and tooth decay is still treating a symptom of a systemic disease topically rather than addressing the underlying issues. However, its use in either preventing completely or postponing the necessity to cut into a tooth in order to restore it is to be celebrated as this first filling often marks the beginning of a cycle of destruction which often winds up in an extraction some decades later. Its use in promoting proper bony healing post-extraction is also to be welcomed.