Post-operative Pain and Apical Healing After Root Canal (re)Treatment With Laser-activated Irrigation Versus Sonic or no Activation

When a tooth's nerve dies, inflammation can develop at the tip of the tooth's root. Root canal treatment is carried out to allow this inflammation to heal. Sometimes, inflammation persists in a tooth that has already undergone root canal treatment. In such cases, the root canals may be re-treated to allow the inflammation to heal. During root canal treatment, the root canals inside the tooth are cleaned and then filled. Various instruments are used to clear the root canal along its entire length, so that the entire canal can be disinfected using antiseptic products. To allow these products to work more effectively, they can be activated. This activation can be achieved, amongst other methods, using vibrations caused by a plastic tip vibrating at a sonic frequency within the liquid. Another method of activation involves the use of a laser, which delivers pulsed energy. This creates shock waves in the liquid. Previous research has shown that root canals can be cleaned more effectively through the use of activation techniques. This study aims to investigate whether the inflammation present at the root tip heals more effectively following the use of activation methods for the disinfectant. The use of the laser is compared with that of the sonic vibration instrument, and with a group in which the disinfectant is not activated. The effect of the activation method on post-treatment pain is also investigated.

Inclusion criteria: * Patients older than 18 years * Mature permanent tooth * Pulpal diagnosis: pulp necrosis, previously initiated treatment, root filled * Apical diagnosis: asymptomatic apical periodontitis * Pre-operative pain of 0 on the Visual Analogue Scale (VAS) Exclusion criteria: * Permanent teeth with immature roots or open apices * Teeth not eligible for orthograde (re)treatment * Teeth with acute pain * Teeth with periodontal pockets ≥ 5 mm * Teeth with persistent intracanal drainage * Non-restorable teeth * Pregnant women * Patients who took drugs with possible influence on the pain sensation within 12 hours before treatment * Patients with pain from one or multiple teeth * Patients with contra-indications for the use of NSAID * Patients with a known or suspected malignancy * Patients with a history of chemotherapy within five years * Patients with a history of radiation therapy in the head and neck region * Patients with a history of metabolic bone diseases