Limitations of previously published systematic reviews evaluating the outcome of endodontic treatment

Abstract

The aim of this work was to identify the limitations of previously published systematic reviews evaluating the outcome of root canal treatment. Traditionally, periapical radiography has been used to assess the outcome of root canal treatment with the absence of a periapical radiolucency being considered a confirmation of a healthy periapex. However, a high percentage of cases confirmed as healthy by radiographs revealed apical periodontitis on cone beam computed tomography (CBCT) and by histology. In teeth, where reduced size of the existing radiolucency was diagnosed by radiographs and considered to represent periapical healing, enlargement of the lesion was frequently confirmed by CBCT. In clinical studies, two additional factors may have further contributed to the overestimation of successful outcomes after root canal treatment: (i) extractions and re-treatments were rarely recorded as failures; and (ii) the recall rate was often lower than 50%. The periapical index (PAI), frequently used for determination of success, was based on radiographic and histological findings in the periapical region of maxillary incisors. The validity of using PAI for all tooth positions might be questionable, as the thickness of the cortical bone and the position of the root tip in relation with the cortex vary with tooth position. In conclusion, the serious limitations of longitudinal clinical studies restrict the correct interpretation of root canal treatment outcomes. Systematic reviews reporting the success rates of root canal treatment without referring to these limitations may mislead readers. The outcomes of root canal treatment should be re-evaluated in long-term longitudinal studies using CBCT and stricter evaluation criteria.

Epidemiological evaluation of apical periodontitis prevalence in an urban Brazilian population

“…9 Previously, periapical radiography was the only imaging method available to diagnose post-treatment apical periodontitis. 16 Periapical radiographs were chosen to assess periapical radiolucency because they have a higher sensitivity in detecting periapical osteolytic lesions than panoramic radiographs, especially in the anterior region. 17 Muhammed et al 18 found no statistically significant difference between panoramic radiographs and fullmouth surveys in detecting periapical lesions.…”

Characterization of Successful Root Canal Treatment

“…This contribution may be applied to planning, diagnosis, therapeutic process and prognosis of several diseases. The continuous advance of technology enabled the development of cone beam computed tomography (CBCT) (78,79), which has widen numerous perspectives for application in different research areas and clinical dentistry (80)(81)(82)(83)(84)(85)(86)(87)(88)(89). Imaging resources have been routinely used before, during and after dental treatment.…”

Prognostic factors influencing clinical outcome of nonsurgical endodontic treatment

“…18 It was also suggested that recall rates should be considered in the outcomes of longitudinal studies. 19 The success rate in the present study is questionable because the recall rate was 39.7%. However, the results of the relative impact of the prognostic factors in this study are not meaningless because the frequencies of the predisposing factors in the analyzed sample were similar to those in the total population (Table 1).…”