# Predicting the Failure of Dental Implants Using Supervised Learning Techniques
## 4 Discussion  
The importance of the investigated variables calculated by gain ratio (GainRationAttributeEval module in WEKA) is shown in Table 5. The results indicated the first six items as fixture width, implant system, betel nut chewing, ridge augmentation, fixture length, and alcohol consumption. This order also indicates the extent to which each variable attribute affects dental implant failure, with fixture width being the major influencing factor followed by the implant system and betel nut chewing. * Fixture Width  
Dental implants have different widths according to distinct implant locations (the anterior area, premolars, and molars), with fixture diameters ranging from 3.0 mm to 5.0 mm. However, it is \begin{table}
\begin{tabular}{c c c c c} \hline
**Classifier** & **Accuracy** & **Sensitivity** & **Specificity** & **AUC** \\ \hline DT & 0.679 & 0.590 & 0.768 & 0.670 \\ LGR & 0.624 & 0.607 & 0.641 & 0.644 \\ SVM & 0.628 & 0.581 & 0.675 & 0.628 \\ Bagging + DT & 0.702 & 0.581 & 0.822 & 0.741 \\ Bagging + LGR & 0.625 & 0.573 & 0.678 & 0.674 \\ Bagging + SVM & 0.619 & 0.598 & 0.640 & 0.670 \\ Adaboost + DT & 0.671 & 0.470 & 0.871 & 0.741 \\ Adaboost + LGR & 0.600 & 0.513 & 0.687 & 0.655 \\ Adaboost + SVM & 0.633 & 0.513 & 0.754 & 0.654 \\ \hline \end{tabular}
\end{table} 
Table 4: Results of classification performance. DT: decision tree; LGR: logistic regression; SVM: support vector machine; AUC: area under the receiver operating characteristic curve. \begin{table}
\begin{tabular}{c c c} \hline
**Rank** & **Variables** & **Importance** \\ \hline
1 & Fixture width & 0.02446 \\
2 & Implant system & 0.02091 \\
3 & Chewing betel nut & 0.01907 \\
4 & Ridge augmentation & 0.01817 \\
5 & Fixture length & 0.01519 \\
6 & Alcohol consumption & 0.01234 \\
7 & Sinus augmentation & 0.00965 \\
8 & Location of implant & 0.00768 \\
9 & Timing of implant placement & 0.00708 \\
10 & Factors of missing & 0.00688 \\ \hline \end{tabular}
\end{table} 
Table 5: Importance of the variables. not compulsory to follow such principles for treatments, which are mostly determined by clinical physicians according to individual situations. The DT analysis employed in this study shows that late fixture failure was correlated with fixture width. [PERSON] et al. (2008) proposed that fixture width and occlusal force area have a significant relationship, the main reason being that the occlusal force withstood by the narrow fixtures (diameter \(\leq\) 3.5 mm) is smaller, thus rendering it unsuitable for areas that require stronger occlusion [21]. In addition, the independent \(t\)-test in this study verified that fixture width is correlated with late fixture failure. According to [PERSON] et al. (2013), a one-unit increase in fixture length increases the fixture failure rate 2.9 times, indicating that fixture width plays a crucial role once the fixture is connected to the prosthesis and starts withstanding occlusion force [14]. * Implant system  
Artificial fixtures are a type of medical equipment with various systems and brands on the market, and the greatest differences between them lie in fixture surface treatment, the appearance of the artificial tooth root, and the fixture and abutment connections. Fixtures have been developed and produced by conventional manufacturers such as Straumann and Nobel Biocare, and today their fixture surface treatment technology is capable of achieving long-term osseointegration success [22]. The greatest distinction in the appearance of the artificial tooth roots is that they are either column- or cone-shaped. The capacity to withstand forces is different according to distinct connections and shapes [23]. Based on a systematic literature review of medical databases, [PERSON] et al. (2008) identified 27 studies, of which 15 focused on internal connections, whereas the other 12 related to external connections. Their analysis revealed that the conditions for abutment screw loosening differed according to the connection method [24].