Root canal complications: 'the hypochlorite accident'.

Root canal treatment is performed routinely in dental practice, using sodium hypochlorite which serves as an effective irrigant. The literature reviewed shows that several complications following irrigation with sodium hypochlorite may occur, but few practitioners are aware of it and its management. Such complications include injury to skin, oral mucosa and eyes, damage to clothing, air emphysema, allergic reactions, and injection beyond the foramen. In this article, a case report of injection with sodium hypochlorite beyond the foramen is presented, together with a review of the recent literature regarding common manifestations and case histories. The literature shows no standard management of this condition, but symptomatic therapies are discussed. It is important to minimize the risk of sodium-hypochlorite-induced damage during root canal therapy by use of protective measures, appropriate instrumentation and techniques, and consider alternate irrigation solutions.

Hypochlorite accident during wndodontic therapy with nerve damage - A case report.

Endodontic therapy is a routinely practised clinical procedure with few reported complications but, as a bleaching agent, inadvertent spillage of sodium hypochlorite beyond the root canal system may result in extensive soft tissue or nerve damage, and even airway compromise. Although very rare, complications arising from hypochlorite extrusion beyond the root apex are described. NaOCl causes oxidation of protein and lipid membrane and causes necrosis, hemolysis and dermal ulcerations (2-4). Neurological complication are very rare. Paraesthesia and anaesthesia may affect the mental, inferior dental and infra-orbital branches of the trigeminal nerve and normal sensation may take many months to  completely resolve (6, 7). Nerve damage (the buccal branch) was described in 2005 by Witton et al. (8) and patients exhibited a loss of the naso-labial groove and a down turning of the angle of the mouth and the motor function was regained after several months. We present a case in which the extrusion of NaOCl solution during endodontic therapy led to important destructive effects on soft tissues and nerves. The arisen medico legal issues are discussed.

Abducent nerve palsy following dental local analgesia.

A case of temporary abducent nerve palsy, following posterior superior alveolar nerve block during removal of an upper third molar tooth is presented. The relevant anatomy and other causes of sixth nerve palsy are considered, together with guidelines for the management of such an occurrence.

Chronic trichloroethylene intoxication: a new approach by trigeminal-evoked potentials?

Trigeminal nerve impairment is frequently seen in chronic trichlorethylene intoxication (TRI). A total of 104 occupationally exposed subjects were selected for study because they were employed at a highly exposed workplace. They were studied by clinical examination and by trigeminal somatosensory evoked potentials (TSEP). Normal values for TSEP were obtained from the study of 52 healthy nonexposed subjects. Facial hypoesthesia, when present, was global and predominant in the mandibular and maxillary nerve areas, associated or not with absent reflexes. A disturbed TSEP was found in 40 subjects which was predictable from their clinical symptoms. Correlation with exposure parameters (duration of exposure, trichlorethanol, and trichloracetic acid urinary rates) was mainly observed in subjects presenting both clinical and electrical alterations. Electrical alterations alone were less predictive. An abnormal TSEP may thus provide objective determination of risk assessment in the absence of clinical signs.

Lesions of the inferior alveolar nerve arising from endodontic treatment.

A lesion of the IAN following endodontic treatment of the lower molars and premolars is not a rare event and presents an uncomfortable situation both for the dental surgeon and the patient. Injury can result on the one hand by direct intrusion of the instrument through the apex into the mandibular canal, and on the other by the filling material which becomes forced into the mandibular canal. In the latter case, a nerve lesion will only result when the filling material contains neurotoxic substances such as paraformaldehyde. With a direct lesion or when forcing of resorbable filling material into the mandibular canal is suspected, one should first employ a wait-and-see approach, because usually the only nerve damage is in the form of neuropraxy or axonotmesis for which there is a high rate of spontaneous regeneration. However, if neurotoxic filling material is introduced into the direct vicinity of the nerves, the mandibular canal should be opened and the filling material should be removed as early as possible. If the filling material is forced directly within the endoneurium between the nerve bundles, the damaged nerve sections must be resected and bridged using transplants from the sural or greater auricular nerves.

[Overfilling into the mandibular canal as an endodontic complication. A review]. / Uberfüllung in den Mandibularkanal als endodontische Komplikation. Eine Ubersicht.

As a consequence of traumatic and toxic injury of the inferior alveolar and the mental nerves, disturbances of sensibility may develop during and after root canal treatment. Several reasons are possible. In most cases, however, such disturbances are the result of root canal filling materials that have been pressed into the mandibular canal. Based on all cases reported in the literature, this review summarizes and discusses symptoms, therapy, prognosis and prophylaxis of such sensibility changes following endodontic overfilling into the mandibular canal.