# Prevalence of Root Canal Treatments among Diabetic Patients: Systematic Review and Meta-Analysis
## 3 Results
### Quality Assessment and Risk of Bias  
Quality assessment and risk of bias was evaluated for each study (Table 2). According to the guidelines provided by the Centre for Evidence-Based Medicine in Oxford [33], all the studies were classified as level 4. Four out of eight studies were classified as having a high risk of bias [11; 15; 21; 41], and four of them were classified as having a moderate risk of bias [13; 14; 16; 40]. None of the included studies were classified as having a low risk of bias. Figure 1: Flow diagram of the search strategy of the systematic review and meta-analysis following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines 2020 [31]. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline
**Authors** & **Year** & **Study Design** & \begin{tabular}{c} **Sample** \\ **Size** \\ \end{tabular} & \begin{tabular}{c} **No of** \\ **Teeh** \\ \end{tabular} & \begin{tabular}{c} **Gender (\%)** \\ \end{tabular} & **Age** & \begin{tabular}{c} **Radiographs** \\ **RGT** \\ \end{tabular} & \begin{tabular}{c} **Wevalence** \\ **of FFT (\%)** \\ \end{tabular} & \
\begin{tabular}{c} **People with at** \\ **Least One RGT (\%)** \\ \end{tabular} &
\begin{tabular}{c} **Type of** \\ **Evidence** [33] \\ \end{tabular} \\ \hline
**[PERSON] et al.**[21] & 2005 & Cross-sectional & \begin{tabular}{c} 32 \\ type 2 \\ \end{tabular} & 692 & \begin{tabular}{c} 12 men’ \\ 20 women \\ \end{tabular} & 43-74 & \begin{tabular}{c} Periapical \\ (I observer) \\ \end{tabular} & 12 & 2 & 31 & 4 \\ \hline [PERSON] et al.**[11] & 2011 & Cross-sectional & \
\begin{tabular}{c} 50 \\ type 2 \\ \end{tabular} & 1095 &
\begin{tabular}{c} 20 men’ \\ 30 women \\ \end{tabular} & 44-83 & Panoramic & 85 & 7.8 & 70 & 4 \\ \hline
**[PERSON] et al.**[15] & 2012 & Cross-sectional & \
\begin{tabular}{c} 30 \\ type 2 \\ \end{tabular} & 652 &
\begin{tabular}{c} 12 men’ \\ 18 women \\ \end{tabular} & 40-69 & Panoramic & 85 & 13 & 76.7 & 4 \\ \hline
**[PERSON]-** & 2015 & Cross-sectional & \begin{tabular}{c} 83 \\ type 2 \\ \end{tabular} & 1751 & \
\begin{tabular}{c} 49 men’ \\ 51 women \\ \end{tabular} &
\begin{tabular}{c} 666 \(\pm\) 10.6 \\ 51 women \\ \end{tabular} & 58 & 3.3 & 32.5 & 4 \\ \hline
**[PERSON] et al.**[40] & 2017 & Cross-sectional & \begin{tabular}{c} 926 \\ type 2 \\ \end{tabular} & 25,028 & \begin{tabular}{c} 540 men’ \\ 386 women \\ \end{tabular} & \
\begin{tabular}{c} \textgreater{}18 \\ \end{tabular} &
\begin{tabular}{c} Panoramic \\ (2 observers) \\ \end{tabular} & 1541 & 6.16 & 4.6 & 4 \\ \hline
**[PERSON]**[16] & 2017 & Cross-sectional & \begin{tabular}{c} 145 \\ type 2 \\ \end{tabular} & 3111 & \
\begin{tabular}{c} 7 men’ \\ 74 women \\ \end{tabular} & Not provided &
\begin{tabular}{c} Panoramic \\ (2 observers) \\ \end{tabular} & 130 & 4.18 & Not provided & 4 \\ \hline
**[PERSON] et al.**[13] & 2020 & Cross-sectional & \begin{tabular}{c} 216 \\ type 2 \\ \end{tabular} & 4514 & \
\begin{tabular}{c} 117 men’ \\ 99 women \\ \end{tabular} & Not provided &
\begin{tabular}{c} Panoramic \\ (3 observers) \\ \end{tabular} & 173 & 3.8 & 12.5 & 4 \\ \hline
**[PERSON] et al.**[41] & 2020 & Cross-sectional & \begin{tabular}{c} 50 \\ type 2 \\ \end{tabular} & 1079 & \
\begin{tabular}{c} 23 men’ \\ 27 women \\ \end{tabular} & 18-45 &
\begin{tabular}{c} Panoramic \\ (I observer) \\ \end{tabular} & 72 & 6.7 & 76 & 4 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Characteristics of the included studies, main outcomes and type of evidence. Figure 3: Forest plot of the studies that have calculated the percentage of people with at least one RFT in the total sample [11; 13; 14; 15; 21; 40; 41]. Figure 2: Forest plot of the primary meta-analysis showing the prevalence of RFT in the diabetic adult population [11; 13; 14; 15; 21; 40; 41].