Oral Cryotherapy Studies
Use of Oral Cryotherapy and Ice in Dental Treatment
Cooling the mouth (oral cryotherapy) during and after dental treatments has been proved to be an effective strategy to manage post-operative oral pain and discomfort. Several research studies have reported the use of irrigation with cold fluids (with saline being commonly used) for reducing pain (as an anesthetic) during dental procedures for treating periodontitis, in root canal treatment, and in molar surgery. In addition, oral inflammatory conditions such as hyperplasia can also be treated with oral cryotherapy. Further, cooling the teeth and root surfaces has been shown to result in significant reduction in pain and bacterial infection. An interesting utility of oral cooling in improving taste and appetite has also been reported, specifically in a condition known as dysgeusia.
The use of ice cubes, ice popsicles, iced cotton buds, and ice packs has been reported in dental applications, in addition to cooling using liquid nitrogen, nitrous oxide, and refrigerants.
Pain and discomfort is a major problem in dental treatments including tooth extraction, debridement, surgery, and root canal treatment. Consequently, patient compliance and recovery are significantly affected.
The use of anesthetic, analgesic, and anti-inflammatory drugs has been done conventionally to address dental and oral pain and inflammation. Cooling of the mouth, teeth, and gums has also been reported as an alternative strategy for managing dental pain.
The earliest reports of cooling the mouth using ice to manage oral and dental pain can be traced back to the late 1980s.
This report summarizes all existing information of the use of cooling methods including ice as a form of anesthesia and as treatment for specific oral and dental conditions. The information is classified based on the source, consisting of research articles, medical reviews, clinical trial data, patent records, product information, and other non-technical literature such as magazine articles or other web-based media. Information sources are cited and included in the report with hyperlinks wherever possible. All downloaded literature has been collated.
- A recent randomized prospective clinical trial evaluated oral cryotherapy in 100 symptomatic apical periodontitis patients. The trial showed that three different types of oral cryotherapy were effective in reducing pain in these patients.
- A multicenter clinical trial with 210 patients showed that cold (2.5 °C) saline irrigation reduced pain significantly.
The first available report of oral cryotherapy is the use of ice to ease toothache, published in 1988.
In the last decade, several individual research studies have reported the benefits of oral cryotherapy in treating dental conditions.
- A study in 2010 reported that the use of ice popsicles reduced discomfort and self-mutilation in children after dental treatment.
- A study published in 2015 found that ice cones were more effective as pre-cooling agents for pain reduction prior to surgery than benzocaine or a refrigerant.
- A 2017 study reported the use of iced cotton buds as an effective tool for palatal anesthesia.
- A study in 2016 on 75 teeth undergoing single-visit root canal treatment showed that irrigation with cold (2–4 °C) saline after root canal treatment resulted in significantly lesser pain.
- A similar study in 2017 reported pain reduction in root canal treatment of teeth with vital pulps.
- A study in 2015 on extracted teeth found that a five-minute irrigation of 20 teeth with cold (2.5 °C) saline resulted in a 10 °C temperature reduction of root surfaces for four minutes.
- In 2013, a study on 86 teeth reported the reduction of bacteria (Enterococcus faecalis) in root canals due to irrigation with a cryogenic fluid.
- Because some dental procedures may generate excessive heat, such as those used to severe material during filling, which may cause tissue damage and pain, oral cryotherapy would be a useful addition to such procedures.
- In addition, oral cryotherapy was shown to a potential useful treatment for inflammatory conditions of the mouth such as specific types of gingival hyperplasia. In this study, liquid nitrogen was sprayed directly onto the tooth surface after xylocaine administration. Six sessions each consisting of four 20–30-second applications followed by 30-second thawing were used and found to be effective.
- A case report published in 2016 used cryosurgery with nitrous oxide delivery via a cryoprobe to effectively treat mouth mucocele, a salivary gland disorder.
- An interesting study published in 2010 describes the beneficial effect of ice cube placement in the mouth in alleviating dysgeusia, which is a distortion of the sense of taste leading to loss of appetite.
- A review published in 2016 states that the dental physician James Arnott introduced the use of ice for local anesthesia in dentistry.
- A letter published last in 2017 suggests intermittent cooling at intervals of a few hours rather than continuous cooling to avoid negative effects of cooling such as hypoxia or tissue death in dental tissues. Such effects may occur because the reduced temperature inhibits nerve transmission, which can effectively reduce pain but can also result in necrosis if uncontrolled. The letter also suggests the use of negative irrigation to ensure that root apices are cooled.