Alveolar bone loss is considered a primary symptom of periodontal diseases. Mostly, the assessment and treatment decisions depend on clinical measurements supported by conventional imaging modalities. However, 2D imaging has its own limitations for detecting bone defects, including overlapping. An estimation of bone loss bucco-lingually has led to the consideration of 3D imaging. However, to what extent the CBCT is effective in the diagnosis of periodontal diseases is not yet clear. Accordingly, our systematic review was designed to summarize the available evidence according to the hierarchal model of efficacy developed by Fryback et al. [34].
In our systematic review, we decided to exclude studies that are published in any language other than English because of time restriction. In addition, case reports and narrative reviews are considered in the literature as low-evidence studies. Studies addressing periapical conditions and implant-related periodontal problems were also excluded as they are beyond our aspect in this review. In the meantime, it was decided to not include studies conducted ex vivo where the periodontal defects are created artificially since we believe those results will not mimic the CBCT’s performance when conducted on humans.
Technical efficacy level:
It seems most of the studies conducted on the use of CBCT in periodontal disease were aimed at performance detection, accuracy estimation, or the treatment outcome assessment. The authors found no study reported in the literature dealt with the technical aspect of CBCT.
Diagnostic accuracy level:
As mentioned earlier in this review, the QUADAS 2 tool was used for the quality assessment of diagnostic accuracy studies. Based on our inclusion criteria, we decided to include studies done in vivo they represent a more common instance when comparing CBCT to intrasurgical findings or comparing radiographic methods to each other. However, it was found that some sources [69,70,76-78] did not use explicit reference standards in their studies.
Cimbaljevic et al. [66] compared the periodontal probing with CBCT in the terms of furcation involvement in the absence of a reference standard. Likewise, Darby et al. [67] addressed the discrepancies in the clinical measurements obtained from patients’ records with their available CBCT images. A study conducted by Suphaanantachat et al. [73] compared CBCT to conventional intraoral radiography. However, they did not use an actual reference standard for comparison. Similarly, Zhu J. et al. [75] has focused on the reproducibility of the different parameters of CBCT for the furcation involvement evaluation, and hence, no reference standard was used.
Diagnostic thinking:
A study published by Walter et al. [86] on decision-making revealed discrepancies between clinically and CBCT-based therapeutic treatment approaches. The discrepancy was found after 59–82% of the teeth were investigated to find out whether less invasive or most invasive treatment should be considered. However, they concluded that CBCT provides informative details in cases of furcation involvement, and hence, it is considered a reliable tool in decision-making regarding treatment of furcation involvement.
Therapeutic efficacy:
According to our interpretation and in correlation with the hierarchical model of efficacy [34], we found that the study conducted by Pajnigara et al. [87] fits on this level. They investigated the pre and post-surgical measurements of clinical and CBCT for furcation defects. Although they reported statistically significant differences between; clinical-presurgery CBCT (P < 0.0001, 95% CI) and clinical-post surgery CBCT; the three-dimensional imaging gives dental practitioners the chance to optimize treatment decisions and assess the degree of healing more effectively.
Patient’s outcome efficacy:
Our systematic review has revealed eight studies that used CBCT to assess the results of treatment provided for periodontal diseases [88-95]. However, it seems that this study is in disagreement with a previously published review [6]. They did not identify any study on the level of patient outcome. The reason for this could be the difference between our inclusion and exclusion criteria and theirs. All studies agreed that CBCT is a reliable tool in the assessment of the results of treatment using a bone graft.
Societal efficacy:
The study reported by Walter et al. [82] has shown that the use of CBCT decreases the cost and time for periodontitis screening. However, CBCT should only be advised in cases of advanced therapy. Further studies with a sufficient number of patients were suggested.
Systematic reviews:
Our review has resulted in six studies, which are systematic reviews. Each review is supposed to adhere to the criteria provided by AMSTAR and scores YES whenever applicable. The review published by Haas et al. [96] did not elaborate on whether they included the study registries or consulted content experts in the field in terms of comprehensive literature search strategy. Although a meta-analysis was conducted in such a review, the review authors did not assess the potential impact of risk of bias on the results of the meta-analysis or other evidence synthesis. Moreover, the authors did not carry out an adequate investigation of publication bias (small-study bias) or discuss its likely impact on the results of the review. Based on our interpretation, the study has not reported any source of funding or mentioned any conflict of interest.
The study by Walter et al. [94] did not clearly have an explicit statement that the review methods were established prior to the conduct of the review and did not justify any significant deviations from the protocol. In addition, only one database has been searched for relevant studies. According to the AMSTAR2 criteria, the included studies were not described adequately. The study has not reported on the source of funding for the individual studies included in the review. To our knowledge, the risk of bias has not been elaborated upon in the relevant sites in the review. Moreover, the review authors did not account for the risk of bias in individual studies when interpreting or discussing the results of the review. In addition, the authors have not reported any source of conflict including any funding they received for conducting the review.
The review by Anter et al. [33] addressed the accuracy of the CBCT as a tool for the measurement of alveolar bone loss in periodontal defects. However, the authors did not report that they followed PICO, which is a framework for review question formulation [40]. In terms of a comprehensive search strategy, we saw that this review did not fulfill the criteria regarding study registries and expert consultation in the field. Furthermore, the authors did not conduct the search in duplicate for the purpose of study selection. The review authors had also not performed data extraction in duplicates. According to our interpretation, the included studies were not described in appropriate detail. Additionally, the source of funding for each relevant individual study was not reported.
The study reported by Choi et al. [98] did not specify whether if there was a deviation from protocol, meta-analysis plan, or causes of heterogeneity if appropriate. In addition, a list of the excluded study in association with a justification for exclusion of each potential study has not been provided. Regardless of whether it is one of the targets of the review, this review has not discussed any potential risk of bias of the included studies. Moreover, the source of funding of each included study was also not reported. It could be included that this review does fulfill the AMSTAR2 [100] checklist to some extent.
The review by Woelber et al. [99] neither mentions any deviation from protocol whenever applicable nor elaborates on if is a plan for meta-analysis, if appropriate. In addition, a plan for investigating the possible causes, if appropriate, regarding heterogeneity was also not reported. The source of funding for each included study was not reported either. To some extent, the review fulfills the checklist of AMSTAR2.
According to our systematic review and AMSTAR2 tool, we found the review conducted by Nikolic-Jakoba et al. [6] best fulfills the tool criteria. However, the study's authors did not justify the reason for exclusion of each potentially relevant study from the review. As other reviews were included in our study, the source of funding of each included publication was not reported.