# Crystal Sinus Lift with the Hydrodynamic Technique: Prospective Clinical Study at 3 Years Follow-Up
## 3 Results  
At each stage of this study, 61 patients were considered potentially eligible and examined for confirmation. According to the exclusion criteria, 54 patients were confirmed as eligible at baseline. Sample details at baseline and implant-prosthetic features are provided in the following table (Table 1).  
\begin{table}
\begin{tabular}{l l} \hline _Sample features_ & \\ \hline Number of patients & 54 \\ \hline Females & 25 \\ \hline Males & 29 \\ \hline Average age (range) & 54.5 (31–78) \\ \hline _Implant details_ & \\ \hline Number of implants & 54 \\ \hline TTi 3.3 \(\times\) 9 & 9 \\ \hline TTi 3.3 \(\times\) 11 & 11 \\ \hline TTi 3.8 \(\times\) 9 & 17 \\ \hline TTi 3.8 \(\times\) 11 & 15 \\ \hline _Implant site_ & \\ \hline
16 & 8 \\ \hline
17 & 19 \\ \hline
26 & 21 \\ \hline
27 & 4 \\ \hline \end{tabular}
\end{table}
Table 1: Sample features at baseline, implant details, and implant sites.  
1. _The Implant Survival Rate_  
Out of 54 implants placed, only one implant was lost during the follow-up period, resulting in an implant survival rate of 98.04%. The implant was lost during the osseeintegration period, leading to early failure.  
Kaplan-Meier survival analysis was conducted to estimate the survival probability over time. The survival rate at the end of the three-year period was 98.0% (95% CI: 94.3%--100.0%). The log-rank test indicated no significant differences in survival rates between different implant positions (\(p\) = 0.65).  
2. _Marginal Bone Loss (MBL)_  
The mean and standard deviation for each time point were as follows (Figure 7):  
A repeated measures ANOVA was performed to determine if there were significant differences in MBL over time. The analysis revealed a significant effect of time on MBL (F(3, 159) = 5.82, \(p\) < 0.001). Post-hoc pairwise comparisons using the Bonferroni correction indicated a significant increase in MBL from 6 months to 1 year (\(p\) = 0.015). However, the differences in MBL between 1 year and 2 years (\(p\) = 0.68) and between 2 years and 3 years (\(p\) = 0.82) were not statistically significant.  
3. _Surgical Complications_  
Out of the total cases treated, only one patient (1.85%) experienced a sinus membrane perforation, while an equal number of cases (1.85%) developed maxillary sinusitis. Additionally, we observed a single case (also 1.85%) of bleeding during the procedure. Fortunately, there were no instances of post-operative wound infection (0%) or insufficient lift of the sinus floor (0%). The incidence of surgical complications was recorded as follows (Figure 8):  
Given the small number of complications, descriptive statistics were used to summarize the data. [PERSON]'s exact test was employed to compare the observed frequencies of complications with expected values based on historical data. The test results were not statistically significant for any complication (\(p\) > 0.05), suggesting that the incidence of complications in this study was consistent with what might be expected in similar clinical settings.  
Figure 7: Marginal bone loss values at 6 months, 1-, 2-, and 3-year follow-up (after definitive prosthetic loading). In blue colour the mean is highlighted, in red the standard deviation.