Healing of a Periapical Lesion Non Surgical Approach by Using Calcium Hydroxide

INTRODUCTION

Traumatic injuries generally disrupt the pulpal blood supply causing pulp necrosis and leading to anaerobic conditions favourable for the growth of opportunistic microorganisms, which may subsequently result in the development of periapical lesions.
As a consequence of pathologic changes in the dental pulp, the root canal system can harbour numerous irritants. Egress of these irritants from infected root canal into the periapical tissues can initiate formation and perpetuation of the periapical lesion.
Elimination of the microorganisms, in case of large periapical lesions, has been a challenge for the clinician. The polymicrobial infection makes sterilization of the root canal system difficult.
Both chemical and mechanical debridement procedures are essential in effectively disrupting and removing the microbial ecosystem that is associated with the disease process. Thus, whenever a pulp is removed and the canal treated and filled in a manner favorable to a physiological reaction, we can expect a satisfactory percentage of endodontic success.

Case Report

A 38-year-old male patient, with no relevant medical history, presented with a painful swelling, in the anterior portion of the upper jaw. The patient gave a history of trauma to the maxillary anterior teeth ten years ago.
Extra oral examination was unremarkable. Intraoral examination revealed painful swelling of the palatal mucosa, adjacent to tooth 22. A radiographic evaluation demonstrated periapical lesion associated with 22 [Fig 1]. There was a large radiolucent lesion with a uniform radiolucency and well-defined margins involving the apex of the tooth.
Vitality test was negative with tooth 22.

Taking into account the medical and dental history of the patient, a nonsurgical endodontic treatment was planned, to treat the involved tooth.
The access cavity was prepared without local anaesthesia. The root canal was negotiated with a size 10 hand file. After achieving apical patency, the canal was negotiated with a size 15 hand file and a working length radiograph was recorded using the same [Fig 2] Subsequently biomechanical preparation was performed by the crown down technique using pro taper gold system of rotary files.

The tooth was irrigated with NaOCl 5.2%, EDTA 17% and final irrigation was done with Chlorhexidine 2%.
After drying the canal with sterile paper points Calcium hydroxide ( Cal Excel by Ammdent) dressing was placed.[Fig 3]

The paste was changed every month for a period of 3-months until the teeth displayed no symptoms.
A master cone radiograph was recorded and root canal obturation was performed with AH plus sealer (Dentsply) using lateral condensation followed by a coronal restoration with composite resin. [Fig 4 and Fig 5]

After a two year follow-up period the patient was asymptomatic. Moreover radiographic examination revealed resolution and adequate healing of the periapical radiolucency. [Fig 6]

Discussion

The development and progression of endodontic induced lesion is directly associated with the presence of micro-organisms in root canal. The infected root canal is considered to be a poly-microbial infection consisting of aerobic and anaerobic bacteria. The periapical and periradicular lesions are treated by either non-surgically or surgically.
But the non- surgical method should be done initially. The success of the non-surgical endodontic treatment method is based on appropriate cleaning,shaping and filling of root canal.
Adequate biomechanical preparation with the aid of 5.25% NaOCl is currently recommended for the above purpose followed by placement of calcium hydroxide dressing. The favourable clinical and radiographic and histological responses obtained with calcium hydroxide are attributed to the involvement of Calcium and hydroxyl ions in several cellular and molecular mechanisms leading to regeneration of periapical connective tissues.
The benefits of calcium hydroxide include anti-inflammatory action, neutralisation of acidic products, activation of alkaline phosphatase and anti bacterial action. The anti bacterial action is attributed to its ph of 12.5 which results in damage to bacterial cytoplasmic membrane, protein denaturation and damage to the bacterial DNA
Apical patency provides decompression of the periapical lesion. Moreover, the removal of the source of antigen, associated with regular renewal of the calcium hydroxide root canal dressing eliminated the exudate and provided significant resolution of the periapical radiolucency as seen in the follow up radiograph.

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