Present status and future directions: Imaging techniques for the detection of periapical lesions.

Diagnosing and treating apical periodontitis (AP) in an attempt to preserve the natural dentition, and to prevent the direct and indirect systemic effects of this condition, is the major goal in endodontics. Considering that AP is frequently asymptomatic, and is most often associated with a lesion in the periapex of the affected tooth, within the maxillary bones, imaging becomes of paramount importance for the diagnosis of the disease. The aim of this narrative review was to investigate the most relevant classic and current literature to describe which are, to date, the diagnostic imaging systems most reliable and advanced to achieve the early and predictable detection of AP, the best measures of the lesions and the disclosure of the different features of the disease. Dental panoramic tomography (DPT) is a classic exam, considered still useful to provide the basic diagnosis of AP in certain districts of the maxillary bones. Periapical radiographs (PRs) represent a valid routine examination, with few, known limitations. Cone-beam computed tomography (CBCT) is the only system that ensures the early and predictable detection of all periapical lesions in the jaws, with the minor risk of false positives. These techniques can be successfully implemented, with ultrasounds (USI) or magnetic resonance (MRI) imaging, exams that do not use ionising radiations. MRI and USI provide information on specific features of the lesions, like the presence and amount of vascular supply, their content and their relationship with the surrounding soft tissues, leading to differential diagnoses. Further, all the three-dimensional systems (CBCT, USI and MRI) allow the volumetric assessment of AP. Pioneering research on artificial intelligence is slowly progressing in the detection of periapical radiolucencies on DPTs, PRs and CBCTs, however, with promising results. Finally, it is established that all imaging techniques have to be associated with a thorough clinical examination and a good degree of calibration of the operator.

Tratamiento conservador de un proceso expansivo tipo quístico con técnica mínimamente invasiva: caso clínico / Conservative treatment of an expansive processof cystic type with minimally invasive technique:clinical case

Los quistes son cavidades patológicas que adquieren importancia en el ámbito odontológico debido a la gran frecuencia en la que se encuentran en los maxilares y por el rol que el odontólogo presenta en su detección. Dentro de las lesiones tipo quísticas, mencionamos al quiste apical en bolsa donde existe una comunicación entre este y el conducto radicular, cuya curación puede lograrse a través de la terapia endodóntica. En el presente caso clínico se demostró cómo la pasta de hidróxido de calcio colocada en forma temporaria y en sucesivas sesiones en el interior de los conductos de los cuatro incisivos inferiores afectados por un gran proceso quístico, permitió la resolución paulatina hasta la erradicación completa del mismo. Se realizaron sucesivos controles clínicos y radiográficos mediante Rx periapicales, ortopantomografías y tomografías Cone Beam; dichos controles indicaron el momento oportuno de repetir el procedimiento de acuerdo a los resultados obtenidos en la disminución de las dimensiones del proceso quístico, optando por la terapia endodóntica definitiva a los 9 meses. Se destaca la eficacia de este tratamiento conservador, mínimamente invasivo, ante la presencia de ungran proceso quístico, con la finalidad de evitar las técnicas quirúrgicas, en pacientes comprometidos a las citas periódicas necesarias para lograr su erradicación.

The cysts are pathological cavities that acquire importance in the dental field due to the great frequency in which they are found in the jaws and the role that the dentist presents in their detection. Withincysts lesions cyst dental root in pocket can be mentioned, where there is a communication between itand the root canal, whose cure can be achieved through root canal therapy or endodontic therapy. In the present clinical case it was demonstrated how the calcium hydroxide paste placed temporarily andin successive sessions inside root canal of the four lower incisors affected by a large cystic process,allowed the gradual resolution until the complete eradication of it. Successive clinical and radiographic controls were carried out using periapical radiographs, orthopantomographies and Cone Beamtomography, these controls indicated the opportune moment to repeat the procedure according to theresults obtained in the reduction of the dimensions of the cystic process, opting for definitive endodontic therapy at nine months. The effectiveness of this conservative treatment is minimally invasive in the presence of a large cystic process, in order to avoid surgical techniques in patients committed to necessary periodic appointments to achieve eradication.

Management of Cyst-like Periapical Lesions by Orthograde Decompression and Long-term Calcium Hydroxide/Chlorhexidine Intracanal Dressing: A Case Series.

Cyst-like periapical lesions should be treated initially with conservative nonsurgical procedures. In this case series, we describe the clinical and radiographic outcomes of large cyst-like lesions that were treated by orthograde decompression and long-term intracanal use of calcium hydroxide [Ca(OH)2] mixed with 2% chlorhexidine digluconate. Ten cases of cyst-like periapical lesions involving 15 teeth from 10 patients were selected. Maximal radiographic diameters of the lesions ranged from 11 to 28 mm. Nonsurgical procedures were performed, including apical patency, orthograde puncture of cyst-like exudates, chemomechanical preparation, and placement of intracanal Ca(OH)2/CHX dressings, which were periodically replaced during 6-10 months. The root canals were then filled with gutta-percha and sealer. The follow-up periods ranged from 6 to 24 months, and the outcome was classified as healed, healing, or failure. Nine lesions drained copious exudates after canal patency. One lesion only drained bloody serous exudate after periapical overinstrumentation. In 9 patients, intracanal exudation ceased in the first follow-up visit. At the 24-month follow-up, 6 lesions (60.0%) had healed, and 3 lesions (30.0%) were healing, with the corresponding patients being without clinical signs or symptoms. The case of treatment failure was submitted to surgical treatment. Microscopically, the lesion appeared to be an apical cyst with exuberant extraradicular bacterial biofilms attached to the sectioned root apex. This case series supports the use of nonsurgical methods to resolve larger cyst-like periapical lesions.