# Cytotoxicityicity of Bleaching Products: A Systematic Review
## 3 Results
### Study Methodology and Results  
The data collected from the selected studies are shown in Table 4. From the 14 selected articles for the qualitative synthesis, the vast majority used fibroblasts as cell lines and performed the MTT cell viability assay; only three of them evaluate cytotoxicity with pulp cells [15; 18; 31]. ### Study Methodology and Results  
The data collected from the selected studies are shown in Table 4. From the 14 selected articles for the qualitative synthesis, the vast majority used fibroblasts as cell lines and performed the MTT cell viability assay; only three of them evaluate cytotoxicity with pulp cells [15; 18; 31]. \begin{table}
\begin{tabular}{c c c c} \hline
**Author** & **Material** & **Cell** & **Assay** & **Cytotoxicity** \\ \hline \multirow{3}{*}{[PERSON]} & HP gel 40\% (30 min) & & HP 40\%, HP 15\% \textgreater{} C\textasciitif\textgreater{} *** \\  & 40\% + NAC (30 min) & & HP 40\% \textgreater{} HP 15\% \textasciitif\textgreater{} *** \\  & 15\% (90 min) & & HP 40\% \textgreater{} HP 40\% + NAC ** \\  & 15\% + NAC (90 min) & & HP 15\% \textgreater{} HP 15\% + NAC ** \\ \hline \multirow{3}{*}{[PERSON]} & HP 35\% & Fibroblasts & MTT assay & NC \textgreater{} PC ** \\  & G1: SP + H\({}_{2}\)0 (BY, OFP) & & \\  & G2: SP + 20\% CP & & \\  & G3: 20\% CP & Fibroblasts & MTT assay & G1, G2, G4, G5 \textgreater{} G3 at 24 h \\  & G4: SP + 35\% HP & & G1 \textgreater{} G2, G3, G4, G5 at 48 h \\  & G5: 35\% HP & & \\ \hline \multirow{3}{*}{[PERSON]} & 15\% HP & & 15\% HP + 50 \(\upmu\)M VE & \\  & 15\% HP + 100 \(\upmu\)M VE & & 15\% HP + 100 \(\upmu\)M VE, 15\% HP + 125 \(\upmu\)M VE \textgreater{} 15\% HP + 250 \(\upmu\)M VE \textgreater{} & \\  & 15\% HP + 250 \(\upmu\)M VE & & 15\% HP + 375 \(\upmu\)M VE & \\ \hline \multirow{3}{*}{[PERSON]} & 10 and 3\% BS & & \\  & DL & & \\  & DB & Fibroblasts & MTT assay & DB \textgreater{} RL \textgreater{} DL \textgreater{} 3\% BS \textgreater{} UBS \textgreater{} \\  & RL & & 10\% BS \\  & UBS & & \\ \hline Koulaouzidou & Pt and HP & BHK21/C13 L929 & MTT assay & HP \textgreater{} Pt BHK21/C13 \textgreater{} L929 \\ \hline \multirow{3}{*}{Kurzmann} & Gel & & \\  & Gel-HP & & \\  & Gel-TiO\({}_{2}\) & Fibroblasts & MTT assay & Gel-HP \textgreater{} Gel-TiO\({}_{2}\)/Ag \textgreater{} Gel \\  & Gel-TiO\({}_{2}\)/Ag & & \\ \hline \multirow{3}{*}{Llena} & HP (Nor-HP, Opal-HP) & & \\  & CP (Nor-CP, Opal-CP) & HDCP & MTT assay & Opal-HP \textgreater{} Nor-CP, Opal-CP, \\  & & & \\  & G1: HP & & \\  & G2: Zoom & & \\  & G3: Zoom® + irradiation & Fibroblasts & MTT assay & Zoom® + irradiation \textgreater{} HP \\  & G4: irradiation only & & \\ \hline \multirow{3}{*}{Ribeiro} & 20 wt\% CP & & \\  & 2.1\% papain-based whitening & & \\  & 3.1\% ficin-based whitening 1\% & Fibroblasts & WST-1 assay & CP \textgreater{} bromelin, ficin, \\ \cline{1-1}  & bromelin-based whitening & & \\ \end{tabular}
\end{table} 
Table 4: Data and results obtained from the included studies. \begin{table}
\begin{tabular}{c c c c} \hline
**Name** & **Abbreviation** & **Composition** & **Manufacturer** \\ \hline \multirow{3}{*}{White Gold Home 16\%} & HP gel 40\% (30 min) & & \\  & 40\% + NAC (30 min) & & \\  & 15\% (90 min) & & \\  & 15\% + NAC (90 min) & & \\ \hline \multirow{3}{*}{Nite White 22\%} & NW & 22\% CP & ACP Discus Dental, Culver, CA, USA \\  & & & \\ \end{tabular}
\end{table} 
Table 3: _Cont._Studies reported that a higher concentration of peroxide resulted in an increased cytotoxicity. A difference between commercial brands was also observed which, using the same concentration of product, resulted in different levels of cytotoxicity, probably due to the additives incorporated in their composition [18; 33; 34]. Other compounds were also tested among the included studies to search for formulations with less adverse effects on teeth. These compounds include N-TiO\({}_{2}\)[27], which is also associated with CaO\({}_{2}\)[35]; platinum; or enzymes such as bromelain, ficin, and papain incorporated into whitening products [29].