Sodium hypochlorite in endodontics

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experienced acute severe facial pain and swelling. Occipito-mental
radiographs demonstrated an air fluid level
in the right maxillary sinus. The antrum was drained
surgically under general anaesthesia. Three weeks
later most of the symptoms had resolved and only the
premolar presented with localised discomfort; this led
to the decision to extract the tooth. Further healing was
uneventful and complete.
Allergic reactions to NaOCl
Hypersensitivity reactions to sodium hypochlorite have
also been reported. Kaufman and Keila125 reported a
case which was detected before initiation of endodontic
therapy so that the patient was referred to an allergist.
Following a skin patch test, the allergist diagnosed a hypersensitivity
to household materials containing NaOCl
and recommended not using NaOCl during root canal
treatment. The canals were irrigated with Solvidont and
the procedure was uneventful. In a second case, sodium
hypochlorite (1%) was used for irrigation of a maxillary
central incisor with midroot horizontal fracture. The
patient immediately reported severe pain and a burning
sensation, within a few seconds the upper lip and cheek
up to the infraorbital area became swollen, accompanied
by ecchymosis and profuse haemorrhage from the root
canal. Pain diminished after a few minutes but the patient
complained about problems in breathing and was
referred to an emergency care unit. Systemic corticosteroid
and antihistamine were administered intravenously
and antibiotics were prescribed. Swelling resolved after
three days, but a paraesthesia on the left side of the face
remained for 10 days. Further endodontic therapy was
performed with hydrogen peroxide and sterile saline
and was uneventful. A skin scratch test was performed
some days after the incident and gave a very rapid positive
allergic reaction126 .
Conclusions
• Sodium hypochlorite has a wide range activity against
both Gram positive and Gram negative bacteria
• Sodium hypochlorite is the strongest antifungal agent
among root canal irrigations and medications
• Sodium hypochlorite is the only root canal irrigant
that can destroy the microbial biofilm effectively
• Utilising sodium hypochlorite for decontamination
of the microbial sampling field is controversial
• It seems that dentine reduces or inhibits the antibacterial
activity of sodium hypochlorite
• Sodium hypochlorite is a non-specific proteolytic
agent with an excellent tissue dissolving ability
• Effects of sodium hypochlorite on the mechanical
properties and the cutting efficiency of Nickel-Titanium
instruments are still controversial
International Dental Journal (2008) Vol. 58/No.6
• It seems that heating sodium hypochlorite increases
its antimicrobial and tissue dissolving abilities
• Sodium hypochlorite exerts deteriorative effects on
mechanical properties and chemical composition of
dentine
• Effects of sodium hypochlorite on the bond strength
of bonding systems are still controversial
• Excellent haemostatic activity of sodium hypochlorite
may enhance the prognosis of vital pulp therapy
• Cytotoxicity and tissue toxicity of sodium hypochlorite
is well documented
• Most complications of the use of sodium hypochlorite
appear to be the result of its inadvertent injection
beyond the root apex which can cause violent tissue
reactions (hypochlorite accident)
• In rare cases sodium hypochlorite may cause allergic
reactions.
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