## 4 Discussion  
The results of the present study reject the null hypothesis (H\({}_{0}\)) that there is no difference in the retrievability and damage to the implant-abutment connection of fractured abutment screws between the conventional and drilling techniques. While various techniques were employed, no statistically significant differences were found among them. However, the non-irrigation drilling techniques with the Phibo, Rhein83, and Sanhigia drilling systems demonstrated a higher retrieval success rate of 90% for fractured screws, compared to only  
Figure 8: Box plot of the volumetric ratio (%) between the pre- and postoperative volumes of the internal threads at the conical internal hex implant-abutment connection among the conventional, Phibo, Rhein83, and Sanhigia study groups. The median value is represented by the horizontal line in each box. The \(p\)-value corresponds to the comparison between the means (ANOVA). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Study Group** & \(n\) & **Mean** & **SD** & **Minimum** & **Maximum** \\ \hline Conventional & 10 & 2.52 a  & 0.95 & 1.35 & 3.80 \\ Phibo & 10 & 2.62 a  & 1.02 & 1.01 & 3.99 \\ Rhein83 & 10 & 2.34 a  & 1.23 & 1.00 & 3.94 \\ Sanhigia & 10 & 2.40 a  & 1.26 & 1.00 & 4.53 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Descriptive statistics of the volumetric ratio (%) between the pre- and postoperative volumes of the internal threads at the conical internal hex implant–abutment connection. 50% for the conventional technique. This raises questions about the practical efficacy of less invasive approaches. The scientific literature has yet to establish an efficient and predictable protocol for the removal of fractured abutment screw fragments from within dental implants. Current studies on managing these fractures are limited, and no scientific evidence is currently available to guide clinicians in choosing the most effective or manageable technique [7; 10]. Additionally, there is no documentation on the volumetric impact at the implant-abutment interface following fractured screw removal. Ideally, an effective extraction of a fractured screw within an implant should avoid damage to the internal threading to prevent adverse outcomes, such as implant removal [12; 13]. If the internal threading remains intact, only a new screw would be necessary, allowing the reuse of both the implant and the prosthesis. A previous study emphasized the importance of avoiding damage to the implant connection and access channel during fractured screw removal, particularly with internal connection implants [9]. Additionally, fractured screw removal is crucial to maintaining implant functionality [14]. Moreover, it has been highlighted that abutment screw fractures could increase the gap at the implant-abutment interface, leading to peri-implantitis development [15]. This underscores the clinical importance of removing fractured abutment screws. However, maintaining the integrity of an implant's internal thread is challenging, with damage rates of 9.8% reported, which sometimes prevents subsequent prosthetic placement. In addition, an internal thread damage rate of 13.33% has been reported [7; 10]. These drilling techniques have emerged in response to the mechanical complications associated with implants, such as screw fractures. Potential mechanical complications include loosening, screw fractures, wear, prosthesis fractures, and damage to other system components [6]. Despite numerous clinical and in vitro studies, the exact causes of these complications remain unclear and may stem from improper prosthesis fitting [16]. Notably, experienced clinicians have been reported to tighten screws at 30-50% less than necessary [17]. The torque applied to the implant prosthetic screw is crucial for achieving the ideal load at the screw joint and preventing loosening [3; 5; 18].