Active Nonsurgical Decompression Technique for the Healing of Large Periapical Cystic Lesions

Antonis Chaniotis, DDS, MScD Difficult Isolation, Regeneration / Revascularization, Endo Implantology


Patient: 35 year-old female, medical history noncontributory

Chief Complaint: Asymptomatic

Dental History:

A 35 year old female patient was referred for evaluation and possible treatment of her right first mandibular molar (Tooth #30) after the accidental discovery of a large periapical lesion associated with her previously root canal treated tooth. The initial treatment was performed 10 years prior to the date of consultation with the author. The patient mentioned that she had bruxism and was wearing a soft mouth guard during the night.

Significant Findings (Tooth #30):

The periodontal evaluation was within normal limits. Radiographic evaluation revealed large periapical radiolucency. CBCT evaluation revealed the magnitude of the periapical lesion in all 3 dimensions. No paresthesia was present.

Pulp and Periradicular Diagnosis (Tooth #30):

Pulpal diagnosis was consistent with a previously treated tooth. Periapical diagnosis was consistent with Chronic Apical Periodontitis.

Treatment Prognosis (Tooth #30): Good

Treatment Plan: Nonsurgical retreatment with active nonsurgical decompression (Tooth #30)

Special Considerations of Performed Treatment:

Periapical lesions develop as sequelae to pulp disease. They often occur without any episode of acute pain and are discovered on routine radiographic examination. Sometimes, a periapical lesion can reach large dimensions jeopardizing the retention of the tooth itself and resulting in aggressive surgical treatment options with a huge impact in the quality of life of the patients. Although the size of the lesion is not a major determining factor in the decision to perform conventional retreatment or surgical removal of the lesion, it is a general belief that small cystic lesions will typically heal with nonsurgical approaches, while larger legions may need additional surgical intervention. In the present case, we describe a nonsurgical approach for the management of large cystic lesions called ‘’Active nonsurgical decompression technique’’.

Since the lesion was in close proximity with the inferior alveolar nerve, the risk of damaging the nerve during surgery was considered high. The risk was judged unacceptable by the patient, who asked for alternative treatment options. Nonsurgical retreatment with active nonsurgical decompression was the treatment option suggested. This technique has been used in some cases of large periapical lesions with great success. The technique uses any kind of vacuum system available in the market in order to create negative intracanal pressure, which results in the decompression of large draining periapical lesions. The high-volume suction aspirator is connected to a micro 22-gaugeneedle, which is inserted in the root canal and sealed airtight with composite material or a block-out resin. When the suction is activated, negative pressure is being created inside the canal lumen resulting in aspiration of the exudate. When the drainage partially stops, the access cavity is closed with temporary cement, which helps in maintaining bacterial control. Unlike the decompression technique, this technique is minimally invasive as the entire procedure is done through the root canal and causes less discomfort for the patient. Various cycles of nonsurgical decompression maybe needed depending on the case.

In the present case, the mandibular molar was accessed under appropriate isolation. Infected gutta-percha was removed with rotary files and eucalyptol solvent. Irrigation was achieved with 6% NaOCl positive irrigation throughout the procedure. The canals were flooded with NaOCl and passive ultrasonic activation of the irrigant was achieved with an ISO 10k ultrasonic file (U file) (figure 3). Manual dynamic gutta percha agitation of the irrigant resulted in continuous purulent drainage from all canals (figure 4). The canals were dried with micro-suction (figure 5) and calcium hydroxide was placed as an intermediate antibacterial dressing (figure 6). The patient was rescheduled 15 days later.

In the next appointment, the tooth was asymptomatic and no changes were noticed by the patient. After placing the rubber dam, the canals were negotiated with rotary files and calcium hydroxide was removed with sterile water rinsing. After copious rinsing with sterile water, cystic exudate started to drain through the distal canal. The yellowish exudate continued for over 10 min and became transparent (figure 7, 8). A 22-gauge needle was attached in the high-speed suction and sealed in the distal canal with Oraseal material (figure 9). Activation of the suction device resulted in creating negative pressure inside the airtight sealed canal space. Active nonsurgical decompression dynamics for 15min resulted in complete drying of the canals and complete drainage of the cystic exudate from the periapical lesion. The canals were obturated with warm vertical condensation technique (figure 10, 11, 12) and the tooth was restored with composite resin restoration with cuspal coverage.


1 year later healing potential was assessed with a follow up panoramic radiograph (figure 13).

In the 2 years follow up evaluation, CBCT evaluation revealed optimal healing dynamics after active nonsurgical decompression approach (Figures 14, 15, 16, 17).

Key Learning Points:

Active nonsurgical decompression offers the following benefits over other techniques:

  1. The patient experiences less discomfort because no surgical procedures (such as marsupialization or surgical decompression techniques) are required

  2. The root canal has no access to the oral environment, which helps in maintaining bacterial control.

  3. The patient does not have to perform any cleaning, as is the case for surgical decompression or marsupialization.

  4. It saves time for both the patient and the dentist.

  5. Invasiveness is minimal because the entire procedure is done through the root canal without compromising anatomic structures, bone or soft tissue

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Commenting Guidelines Please make scholarly cited references or expert opinions suitable for publication. The comments can either be "pro" or "con" with references to the treatment philosophy. We encourage objectivity and detailed demonstration of knowledge/literature.
Ennio Rebellato commented 9 years ago.

Good Morning, Dr Chaniotis, from Melbourne, Australia (the second or third largest Greek-speaking city in the world!) An excellent case result. Very conservative and beneficial for the patient. Very much enjoyed your webinar (at 3.30 am Sunday, Melbourne time). It seem that oral surgeons may be the same the world over! Well done. Ennio

Oliver Pontius commented 9 years ago.

excellent documentation and well presented as always- great job. Oliver

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