Sodium Hypochlorite accident during Root canal procedure is although rare but has been seen in certain cases which can range from showing mild symptoms to severe symptoms in patients which has to be dealt with immediately. Sodium Hypochlorite (Hypo) is the most commonly used Root canal Irrigation liquid which has a pale coloration similar to water and has strong odor due to chlorine concentration. It is also called as “Dakin’s Solution” as it was first introduced by Henry Drysdale Dakin for the treatment of infected wounds during World war I. Its use in Root Canal treatment was first introduced by Walker in 1936 which was later popularized by Grossman in 1941 by publishing his findings of its tissue dissolving ability using 5% NaOCl and its use as a Intracanal medicament.
Sodium Hypochlorite acts as a anti bacterial agent by dissolving the necrotic tissue due to its presence of 5% free chlorine and the high pH levels of pH 12 which helps in dissolving the necrotic tissue in the root canals. Sodium Hypochlorite is decomposed by light and should be stored in dark and cool place to maintain its efficiency.
How to prevent Hypo accidents:
- Syringe containing Hypo and Saline should be marked and separated to avoid any confusion.
- Use only specialized side vented needles
- Use a 32 gauge needle with side venting endodontic syringe (it prevents extrusion of the liquid into the peri apical region)
- Always do Pre-Endo build up before staring Irrigation in Class II cases
- Use a Rubber Dam is must in Root Canal cases
- Use a Luer Lock needle and syringe to avoid opening of needle from the syringe while dispensing the irrigant inside the canal
- Start irrigation only after Working Length determinations as you need to place the needle a minimum of 2mm short of the Apex before irrigating
- Place a rubber stop at 2mm short of the working length for the irrigation needle so you do not overshoot the canal.
- The Needle tip should not be wedged into the canal during irrigation but a up and down motion should be followed, if the tip of needle is wedged it can push the liquid into the apical region due to pressure build up in the canal
- Expand the root canals to a minimum of #25 n.o file before using NaOCl as it helps in reaching the apical regions of the canal
- Irrigant should be dispensed very slowly and with an Up & Down motion at the rate of 3ml in about 2 mins. If you feel any resistance you should immediately stop applying any pressure
- Protective Eye wear should be worn by Dentist and Patient to prevent any drops of Irrigating solution to all into the eyes
- Teach your assistants how to load and handle the syringes properly without
Signs and Symptoms of Sodium Hypochlorite or Hypo Accident:
- Immediate and Severe pain expressed by the patient in the tooth and the surrounding hard tissue
- Increased bleeding from the access opening of the tooth being treated
- Redness and odema or swelling in the gingival tissue surrounding the tooth along with the external face progressing slowly up in case of upper tooth or towards the neck in case of mandibular teeth
- In certain cases parasthesia has also been reported when the Hypo solution comes in contact with any major nerve such as the Mental nerve in cases where the accident involves the 1st or 2nd pre molar.
- In severe cases ecchymosis is also seen on the face in relation to the tooth in question
Treatment and Management of Nodium Hypochlorite or Hypo Accident
Note: “All the below mentioned points are done to relieve the patient of their symptoms, the healing of Hypo accidents does not occur overnight and it takes time to come back to normal. So making the patient understand the situation and how much time it takes to heal is very important.”
- Immediately stop any further procedure like BMP or irrigation
- Immediate forceful irrigation with copious amounts of Normal saline in the root canal should be done for multiple times to reduce the concentration of Hypo in the tissue and neutralize its effect on the tissues.
- Irrigation with Lignocaine solution is also advisable to help reduce pain to the patient
- Analgesic I.M injections like NSAIDS is advisable to reduce the pain to the patient of through oral route which ever you find useful in the situation
- Injecting Corticosteroids such as Dexamethasone at the affected side is advised to reduce the inflammatory reaction of the tissue and reduce the symptoms considerably
- Put the patient of Antibiotics to prevent any secondary infections
- Cold compression at the affected side starting immediately is advised to reduce the occurrence of swelling for 24 hours
- Warm compression and saline rinses are advised post 24 hours from the time of accident to improve local healing.
What to Convey the patient after a Hypo Accident:
- Be upfront and explain the patient what has happened to make sure you avoid any legal issues later on
- Explain the patient about all the symptoms which they might be feeling and how you are taking action to overcome them
- Mention about the Ecchymosis and how the redness or bluish discoloration of skin starts from couple of days after the accident and how it takes 7-10 days to come down on its own and that there is nothing we can do to prevent or avoid it
- Be confident and reassuring to the patient that it will all come back to normal in a few days and there is no serious or permanent damage which has occurred
- Be in contact with the patient constantly to track the symptoms and reassuring him or her that signs and symptoms will come down gradually overtime.
It can be overwhelming for the patient to observe the symptoms and start blaming you for the mistake so be apologetic and make sure that you make the patient understand that it is a complication which can occur with any patient and you will be taking care of it. Other complications of Local Anesthetic include – Transient Hemifacial Paralysis due to Inferior Alveolar nerve block