# Comparison Between Titanium and Thermally Activated Prostheses in Stages Surgery
## 4 Discussion and Conclusions  
Our study compared the results of the stapes prosthesis, where the prosthesis was fixed manually or thermally on the long process of the incus. This fixation should be stable and longstanding. The erosion of the long process of the incus could be a complication of the stapes surgery that the ear surgeon would like to avoid because it leads towards worsening of the hearing and the need for revision surgery. Manual crimping of the prosthesis on the long process of the incus may cause subluxation of the incudo-malleolar joint and intracochlear trauma. Erosion and necrosis of the long process of the incus can be caused if the wire loop is not crimped firmly enough and the vibrations lead to notching of the long process of the incus. Also, if the regrowth of otosclerosis in the footplate area occurs, this might cause notching on the long process of the incus because the prosthesis is fixed inferiorly. The third theory for the long process of the incus necrosis is the compromising of the blood supply by the prosthesis which is attached around the whole circumference. The tip of the incus and the lenticular process have the poorest blood supply; the incudal branch from the anterior tympanic artery enters the root of the long process of the incus and the posterior branch of the anterior tympanic artery forms a mucosal network of vessels over the long process to the incudostapedial joint, anastomosing with vessels ascending the crura of the stapes [8]. Already [PERSON] et al. found that the attachment of band-shaped loops proved to have better contact with the incus than the wire loop prostheses [8]. Titanium as a material proved to have the fewest undesirable deviations. In the study of [PERSON] [12], the air-bone gap closure of crimping (K-piston) and non-crimping (CliP-piston) titanium prostheses was compared. The study could not demonstrate a statistically better air-bone closure for one of titanium pistons. [PERSON] et al. [16] compared the hearing results between the fluoroplastic loop piston and MatrixX titanium prosthesis and also could not find any significant difference between the two prostheses. [PERSON] et al. [17] designed and reported about the NiTiBOND prosthesis, which retained the properties of Nitinol and reduced the risks of lenticular process necrosis. They found that the new designed prosthesis was not inferior to the standard Nitinol prosthesis regarding the hearing results. In the study of [PERSON], authors [18] compared the hearing results of the NiTiBOND prosthesis and titanium K-piston. They observed shorter length of the operation in the NiTiBOND group and the same rate of revision operations (5.6% in NiTiBOND and 5.9 in K-piston group). The postoperative AB gap was 10 dB or less in over 80% in both prosthesis groups. On the other hand, [PERSON] [9] found significantly lesser ABG in NiTiBOND group than in K-piston group. We could not confirm this finding; also, the number of patients compared was larger in our study. The aim of our study was to compare MatriX and NiTiBOND protheses. By our knowledge such a comparison has not been conducted before. The NiTiBOND prothesis was previously compared with K-piston [18]; however, the MatriX prothesis has a band loop, which could have better contact with the long process of the incus than K-piston. The mean age and sex ratio of the included patients was similar in both groups, indicating an appropriate balance of the cohorts. This allows for a direct comparison of prostheses without the influence of demographic factors. Preoperative BC did not show significant differences between the two groups, confirming the comparability of patients before the procedure. Postoperative AC measurements showed a statistically significant improvement in the groups of patients operated on with both prostheses, with a slight preference for the NiTiBOND prosthesis. Mean ABG closure was similar between thetwo groups.