# Cytotoxicityicity of Bleaching Products: A Systematic Review
## 3 Results
### Quality Assessment  
In vitro studies were performed using the modified CONSORT checklist by [PERSON] et al. (2012) [25] consisting of 14 items assessing the quality of the studies (Table 2). All articles present a correctly structured abstract (item 1), as well as an introduction (item 2a) that provides information about the bleaching treatment and the main products to carry it out. The hypothesis and objectives (item 2b) are also clearly stated, as is the description of a specific methodology with the variables studied (items 3 and 4), which allows replication in all the studies analyzed. However, none of them provide an accurate report of the sample size calculation or allocation sequence (items 5-9). It should be noted that the items related to the randomization process are considered \"not applicable\" in in vitro studies on cell samples of this type. On the other hand, all studies reflect the statistical method used (item 10), as well as the level of significance through confidence intervals and/or \(p\) values (item 11). In the discussion section, all the studies include a summary of the most relevant results, as well as a series of comparisons with other published articles. However, only less than half refer to the limitations encountered in the research process (item 12) [26; 27; 28; 29; 30; 31]. Sources of funding are indicated in most of the studies, except in three (item 13) [26; 32; 21]. However, information on the complete trial protocols (item 14) is not mentioned in any of the studies.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Database** & **Search Strategy** & **Result** \\ \hline \multirow{4}{*}{Medline} & N\({}^{\text{c1}}\) (Tooth whitening) OR (bleaching agent) & 6128 \\  & N\({}^{\text{c2}}\) (Cytotoxicity) & 380,758 \\  & N\({}^{\text{c3}}\) (Stem cell*) OR (fibroblast) & 875,315 \\  & N\({}^{\text{c1}}\) AND N\({}^{\text{c2}}\) AND N\({}^{\text{c3}}\) & 35 \\ \hline \multirow{4}{*}{Lilacs} & N\({}^{\text{c1}}\) (Tooth whitening) OR (bleaching agent) & 1035 \\  & N\({}^{\text{c2}}\) (Cytotoxicity) & 1535 \\  & N\({}^{\text{c3}}\) (Stem cell*) OR (fibroblast) & 4358 \\  & N\({}^{\text{c1}}\) AND N\({}^{\text{c2}}\) AND N\({}^{\text{c3}}\) & 4 \\ \hline \multirow{4}{*}{Scopus} & N\({}^{\text{c1}}\) (Tooth whitening) OR (bleaching agent) & 11,264 \\  & N\({}^{\text{c2}}\) (Cytotoxicity) & 433,957 \\ \cline{1-1}  & N\({}^{\text{c3}}\) (Stem cell*) OR (fibroblast) & 977,720 \\ \cline{1-1}  & N\({}^{\text{c1}}\) AND N\({}^{\text{c2}}\) AND N\({}^{\text{c3}}\) & 41 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Results of database searches.  
Figure 1: PRISMA 2020 Flowchart.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c c c c} \hline \hline
**Study [Ref.]** & **1** & **2a** & **2b** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & **12** & **13** & **14** & **\%** & **Value \%** \\ \hline [PERSON] [15] & Y & Y & Y & Y & Y & - & - & - & - & - & Y & Y & N & Y & N & 53\% & 80\% \\ \hline [PERSON] [30] & Y & Y & Y & Y & Y & - & - & - & - & - & Y & Y & N & Y & N & 53\% & 80\% \\ \hline [PERSON] [20] & Y & Y & Y & Y & Y & - & - & - & - & - & Y & Y & N & N & 46\% & 70\% \\ \hline [PERSON] [14] & Y & Y & Y & Y & Y & - & - & - & - & - & Y & Y & N & Y & N & 53\% & 80\% \\ \hline [PERSON] [31] & Y & Y & Y & Y & Y & - & - & - & - & - & Y & Y & N & Y & N & 53\% & 80\% \\ \[PERSON] [23] & Y & Y & Y & Y & Y & - & - & - & - & Y & Y & Y & N & N & 53\% & 80\% \\ \hline [PERSON] [24] & Y & Y & Y & Y & Y & - & - & - & - & - & Y & Y & Y & N & 60\% & 90\% \\ \hline [PERSON] [18] & Y & Y & Y & Y & Y & - & - & - & - & - & Y & Y & N & Y & N & 53\% & 80\% \\ \hline [PERSON] [25] & Y & Y & Y & Y & Y & - & - & - & - & - & Y & Y & Y & N & 60\% & 90\% \\ \hline [PERSON] [26] & Y & Y & Y & Y & Y & - & - & - & - & - & Y & Y & Y & N & 60\% & 90\% \\ \hline [PERSON] [27] & Y & Y & Y & Y & Y & - & - & - & - & - & Y & Y & Y & N & 60\% & 90\% \\ \hline \hline \end{tabular}
\end{table}
Table 2: Modified CONSORT quality analysis of in vitro studies.