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Dental Tribune United Kindom Edition

July 30 - August 5, 201216 Endo Tribune United Kingdom Edition M ost periapical le- sions occur as direct sequelae of chronic apical periodontitis, usu- ally after pulpal necrosis of a tooth. The affected tooth is non-responsive to thermal and electrical pulp tests. Peri- apical lesions often develop slowly and do not become very large. Patients do not ex- perience pain unless there is acute inflammatory exacerba- tion. These lesions are often diagnosed during routine ra- diographic exams. Some peri- apical lesions become large and, in cases of large radio- lucencies, they may be diag- nosed in the absence of any patient complaint. Sometimes, symptoms such as mild sensitivity, swell- ing, tooth mobility and dis- placement may be observed in these cases. Large periapical lesions are often associated with an- terior maxillary teeth, prob- ably due to traumatic injuries. These lesions could be clas- sified as granulomas, pocket cysts (also called bay cysts) and true cysts. Granulomas are usually composed of solid soft tissue, while cysts have a semi-solid or liquefied cen- tral area usually surrounded by epithelium.1 Pocket cysts have an epithelial lining that is connected with the root ca- nal, and true cysts are com- pletely lined with epithelium and not connected with the root canal.2 According to Nair’s3 re- search, based on serial sec- tioning and strict histopatho- logical criteria, the prevalence of pocket cysts to be six per cent, whereas that of true cysts is nine per cent. Previous studies without serial section- ing that reported ranges from six to 55 per cent are proven to contain a great margin of er- ror. The differential diagnosis of large periapical lesions is still a controversial topic. Per- iapical radiographs, contrast media, Papanicolaou smears and albumin tests have proven to be inaccurate in establish- ing a preoperative diagnosis. Only once the post-operative biopsy has been taken, can a diagnosis be established. There is evidence1 that CBCT scans may provide a more accurate diagnosis than biopsy. To obtain an accurate reading, the entire lucency must be scanned for the most lucent or least dense areas. If the least dense area of the CBCT scan shows positive grey-scale values identified as solid tissues, diagnosis will be consistent with granuloma. If it shows negative grey-scale values identifying a semisolid or fluid-filled central area, di- agnosis will be consistent with a pocket or a true cyst. Real- time ultrasound imaging and ultrasound recently demon- strated that they are capable of establishing differential di- agnosis as well.4 There is widespread agree- ment that most granulomas heal after non-surgical root- canal treatment (NSRCT), but there is no consent regarding this in the case of periapical cysts. In Nair’s opinion, based on indirect clinical evidence, it appears that pocket cysts may heal after non-surgical endodontics. He asserts that a pocket cyst is sustained by the microbes within the canal system, but that a true cyst is self-sustaining and will remain after the micro-or- ganisms have been removed from the root-canal system. The new preoperative diag- nostic techniques will be help- ful in the treatment decision process. The following case report describes the management of a particularly large maxillary periapical lesion (involving four anterior teeth) by de- compression with tubing, fol- lowed by NSRCT using interim long-term calcium hydroxide (Ca(OH)2). Case report A healthy 39-year-old male patient with recurrent palatal swelling and buccal abscess- es was referred to our prac- tice (Fig 1). He had had these symptoms for the last two to three years owing to trauma sustained while working with machinery. An RCT on tooth #9 had been performed fol- lowing the incident. One year later, the tooth presented with apparent brown discoloura- tion according to the patient. At the initial examina- tion, tooth #9 was found to be non-vital (non-responsive to cold or electrical stimuli), and teeth #7, 8, 10 and 11 had a cold pulpal response within normal limits. Radiographs revealed a large cyst-like peri- apical lesion that appeared to be centred above the left up- per central incisor (Figs 2 & 3). A panoramic radiograph (Fig 4) confirmed the full ex- Dr Nuria Campo discusses decompression combined with root-canal treatment Large periapical lesion management Fig 1 Buccal abscess Fig 2a Mesio-radial periapical radiograph Fig 2b Ortho-radial periapical radiograph. Fig 2c Disto-radial periapical radiograph Fig 4 Initial panoramic radiograph ‘There is evidence that CBCT scans may provide a more accurate diagnosis than biopsy’ Fig 3 Periapical’s composition showing the full extension of the lesion