## 4 Discussion  
This pilot study retrospectively, for the first time, directly compared immediate and delayed implant placement modalities in patients presenting multiple, mainly bilateral, symmetric dental agenesis second premolar sites with and without deciduous teeth in situ. The observations of this study indicate comparable outcomes in terms of clinical outcomes, namely esthetic and radiographic outcomes after 1-year post-surgery, and clinical complexity. Further, the results indicated a trend towards less pain and increased patient preference in sites treated with immediate placement compared to delayed procedures. While [PERSON], in his seminal work [30], suggested a conservative healing period between tooth extraction and implant placement, immediate insertion of implants into fresh extraction sockets has become a routine protocol supported by literature and recent consensus statements [31; 32]. On the other hand, immediate implant placement--type 1, according to [PERSON] et al., 2004 [32; 33], as defined by the placement of an implant into a tooth socket concurrently with extraction, has also been associated with a significantly \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Category** & **Patient Satisfaction** & **Clinician Satisfaction** & \\ \hline  & **N** & **\%** & **N** & **\%** \\ \hline Not reported & 0 & 0\% & 0 & 0\% \\ Completely satisfied & 5 & 100\% & 5 & 100\% \\ Partly satisfied & 1 & 0\% & 0 & 0\% \\ Not satisfied & 0 & 0\% & 0 & 0\% \\ Not able to judge & 0 & 0\% & 0 & 0\% \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Patient and clinician-reported satisfaction levels as assessed after prosthetic delivery. \begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Treatment Preference** & & **Reason** & \\ \hline  & **N** & **\%** & **N** & **\%** \\ \hline Not reported & 0 & 0\% & 0 & 0\% \\ Immediate & 4 & 80\% & Less pain and faster (4), Immediate restoration (1) & 80\% \\ Delayed & 0 & 0\% & 0 & 0\% \\ No difference & 1 & 20\% & Same perception & 0\% \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Patient-reported preference for immediate or delayed implantation procedures. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Category** & **Patient Satisfaction** & **Clinician Satisfaction** \\ \hline  & **N** & **\%** & **N** & **\%** \\ \hline Not reported & 0 & 0\% & 0 & 0\% \\ Completely satisfied & 4 & 80\% & 5 & 100\% \\ Partly satisfied & 1 & 20\% & 0 & 0\% \\ Not satisfied & 0 & 0\% & 0 & 0\% \\ Not able to judge & 0 & 0\% & 0 & 0\% \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Patient and clinician-reported satisfaction levels as assessed 10 min after surgical treatment completion. elevated risk for complications, such as, e.g., midfacial mucosal recession and papillary height loss following resorption of the facial and interproximal bone [34; 35]. Elevated complication risks were reported for immediate implants in conditions showing, e.g., a deficient buccal and interproximal bone or soft tissue, a thin periodontal biotype, and the absence of implant primary stability [35]. As a result, selection criteria to avoid these clinical scenarios need to be adopted, which may, on the other hand, limit the applicability of immediate placement [35]. Although simultaneous biomaterial grafting may support augmenting buccal bone defects, intrasurgical complications, such as fracturing the cortical buccal bone wall by ankylosed teeth, may further restrict the ability to deliver an immediate placement [36; 37]. Interestingly, the current notion that patients would prefer immediate implant placement (and loading) compared to delayed implant placement could not be substantiated by the present literature or recent consensus reviews, which was recently attributed to the fact that study designs were not necessarily adequate to test patient-reported outcomes [38].