The researchers, from the Dental Institute at King’s College London, say the study is the first to report multiple cases of this rare, but serious, side-effect. The paper aims to raise awareness of possible complications following this type of dental surgery.
The retrospective case series, published in the June issue of European Journal of Oral Implantology, examined 10 patients who attended the orofacial pain clinic at the dental institute, King’s College Hospital site, who reported severe chronic pain following dental implants.
Dental implant surgery involves drilling a hole in a patient’s jawbone to insert a screw that will hold a prosthetic tooth. Chronic pain is a rare complication, which may be due to damage to nerves in the jaw, either directly from drilling during surgery or indirectly from swelling or bleeding after surgery. Chronic post-surgical dental pain does not respond to painkillers and is difficult to diagnose, as patients often have no abnormality that is visible or can be detected on scans.
In this paper, nine out of 10 of the patients reported the pain started immediately after surgery and half of the patients reported experiencing severe pain during surgery despite the use of anaesthesia or painkillers. The patients had experienced pain for an average of 3.4 years before they attended the orofacial pain clinic. Prior to attending the clinic, two patients had their implants removed, but the pain had not stopped.
A pain management regime including prescribed drugs, Botox injections and/or cognitive behavioural therapy only achieved complete relief in one patient, while five of the patients had partial improvement in pain and three of the ten patients experienced no improvement.
The study also observed that six of the 10 patients had a medical history of conditions such as depression, anxiety, irritable bowel syndrome, peripheral neuropathic pain and fibromyalgia.
Pain is now recognised as more than a physiological phenomenon, with psychological and social factors such as depression, anxiety, social stresses and poor coping skills also linked to the development of chronic pain. Neuropathic pain can be difficult to diagnose and treat, as it can arise without any detectable nerve injuries.
Randomised controlled trials have shown that drugs typically provide pain relief to only a proportion of patients with neuropathic pain. Management of this kind of pain may involve lidocaine plasters, capsaicin patches and Botox with further medication for those who don’t respond to initial treatments. Application of capsaicin, from Capsicum chili peppers, in the form of a patch or cream causes an initial period of discomfort and sensitivity, followed by a longer period of pain reduction as receptors are ‘knocked out’. However, many patients do not find it easy to wear a patch on their face, particularly at work, and so wearing the patch overnight is often the only option.
Limitations of the study included the fact that chronic pain following dental implant is a rare condition and due to the small number of patients identified, it is difficult to draw firm conclusions on the risk factors and prognosis from this small group. Larger prospective studies are needed to better understand the mechanisms and extent of post-surgery chronic pain following dental implants.
Dr Maria Devine, lead study author from the King’s College London Dental Institute, said: ‘Whilst we don’t want to worry people unduly, dentists should be aware that certain patients can be at greater risk of chronic post-surgical pain, particularly those with pre-existing chronic pain conditions elsewhere in the body. Patients should be appropriately screened for the risk of developing chronic post-surgical pain during the treatment planning phase, particularly for elective surgery such as dental implants.
‘Chronic pain from dental surgery is a rare complication, highlighted in this small case series, but it is a condition increasingly recognised by the dental profession. More research is needed into this condition and its causes.’
Professor Tara Renton, study author from King’s College London Dental Institute, and lead for orofacial pain services at King’s College Hospital Foundation Trust, said: ‘Chronic post-surgical pain, even after seemingly innocuous dental procedures, can result in long-term debilitating pain for a very small proportion of patients. Dental practitioners need to be aware of permanent mouth pain as a possible complication of implant placement. Every surgery has risks and benefits, and our study highlights that the consent process for dental procedures needs to include the rare possibility of long-term post-surgical pain.’
Devine M, Taylor S, Renton T (2016) Chronic post-surgical pain following the placement of dental implants in the maxilla: A case series. Eur J Oral Implantol 9(2): 179-86