## 4 Discussion  
The effect of the production technique (DLP, SLA, and milling) on the marginal and internal gap values of the resin-based crowns for primary teeth was tested in the present study. The results demonstrated that the production technique was effective on the marginal and internal gap values; thus, the null hypothesis was rejected. Developments in both materials science and subtractive (SM) and additive manufacturing (AM) digital technologies have enabled the production of well-adapted restorations instead of conventional restorations for adults and prefabricated crowns for children [17; 27]. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{\begin{tabular}{c} **Material** \\ **(\(n\) = 10)** \\ \end{tabular} } & \multirow{2}{*}{\begin{tabular}{c} **Production** \\ **Technique** \\ \end{tabular} } & \multirow{2}{*}{**Mean \(\pm\) SD**} & \multirow{2}{*}{**SE**} & \multicolumn{2}{c}{**95\% Confidence Interval**} & \multirow{2}{*}{**Minimum**} & \multirow{2}{*}{**Maximum**} \\  & & & & **Lower Bound** & & & \\ \hline \multirow{4}{*}{\
\begin{tabular}{c} **Marginal** \\ **Gap (mm\({}^{3}\))** \\ \end{tabular} } & DLP & \multirow{2}{*}{2.00 \(\pm\) 0.30 B} & DLP & \multirow{2}{*}{0.095} & \multirow{2}{*}{1.79} & \multirow{2}{*}{2.22} & \multirow{2}{*}{1.67} & \multirow{2}{*}{2.74} \\  & (Asiga) & & & & & & \\ \cline{1-1} \cline{4-10}  & SLA & & & & & & \\ \cline{1-1} \cline{4-10}  & (Formlabs) & & & & & & \\ \cline{1-1} \cline{4-10}  & & Milling & & & & & \\ \cline{1-1} \cline{4-10}  & (Tetric CAD) & & & & & & \\ \hline \multirow{4}{*}{
\begin{tabular}{c} **Internal Gap** \\ **(mm\({}^{3}\))** \\ \end{tabular} } & DLP & \multirow{2}{*}{9.72 \(\pm\) 2.35 b} & DLP & \multirow{2}{*}{0.744} & \multirow{2}{*}{8.03} & \multirow{2}{*}{11.40} & \multirow{2}{*}{7.30} & \multirow{2}{*}{14.66} \\  & (Asiga) & & & & & & \\ \cline{1-1} \cline{4-10}  & SLA & & & & & & \\ \cline{1-1} \cline{4-10}  & (Formlabs) & & & & & & \\ \cline{1-1} \cline{4-10}  & Milling & & & & & & \\ \cline{1-1} \cline{4-10}  & (Tetric CAD) & & & & & & \\ \hline \hline \end{tabular}  
* SD: standard deviation; SE: standard error. The same uppercase letters indicate that the marginal gap values were not significantly different among the production technique groups (\(p\) > 0.05). The same lowercase letters indicate that the internal gap values were not significantly different among the production technique groups (\(p\) > 0.05).  
\end{table} 
Table 2: Descriptive and comparative statistics of the marginal and internal gap values of the production technique groups. In a randomized controlled trial, [PERSON] et al. [28] assessed the clinical outcomes of 3D printed resin crowns (PRCs) and direct composite celluloid crowns for restoring primary molars after pulotomy. Fifty molars were divided into two groups, Group A (PRCs fabricated with biocompatible light-curing composite) and Group B (direct composite crowns using prefabricated celluloid forms). Crowns were evaluated for retention, marginal integrity, and gingival health using USPHS criteria at baseline and after 3, 6, and 12 months. Direct composite crowns exhibited better retention rates, while PRCs showed significantly improved gingival health and marginal integrity throughout the follow-up (\(p<0.05\)). Both types were deemed suitable esthetic options for pulp-treated primary molars, each with distinct clinical advantages. In a multicenter randomized clinical trial, [PERSON] et al. [29] investigated PRCs as a replacement for stainless steel crowns (SSCs) in restoring carious primary molars. Fifty-six molars that underwent pulp treatment were allocated into SSC (\(n=28\)) and PRC (\(n=28\)) groups. During a 12-month follow-up, the plaque index (QHI), gingival index (GI), occlusal wear, and survival rates were measured. While no significant differences in the QHI were noted, PRCs had higher GI scores at 12 months and greater occlusal wear than SSCs (\(p<0.05\)).