Removal capability, implant-abutment connection damage and thermal effect using ultrasonic and drilling techniques for the extraction of fractured abutment screws: an in vitro study

Abstract

The aim of this work was to analyze and compare the removal capability, conical internal hex implant-abutment connection damage and thermal effect using ultrasonic and drilling techniques for the extraction of fractured abutment screws. Twenty abutment screws were randomly fractured into twenty dental implants and randomly extracted using the following removal techniques: Group A: drilling technique without irrigation (n = 10) (DT) and Group B: ultrasonic technique without irrigation (n = 10) (UT). The dental implants were submitted to a preoperative and postoperative micro-computed tomography (micro-CT) scan to obtain a Standard Tessellation Language (STL) digital file that determined the wear comparison by morphometry. Moreover, the thermographic effects generated by the DT and UT removal techniques were registered using a thermographic digital camera. Comparative analysis was performed by comparing the volumetric differences (mm3) between preoperative and postoperative micro-CT scans and thermographic results (°C) using the Student t test. The DT extracted 8/10 and the US 9/10 abutment screws. The pairwise comparison revealed statistically significant differences between the volumetric differences of postoperative and preoperative micro-CT scans of the DT (− 0.09 ± − 0.02mm3) and UT (− 0.93 ± − 0.32mm3) study groups (p = 0.0042); in addition, the pairwise comparison revealed statistically significant differences between the thermographic values of the DT (38.12 ± − 10.82 °C) and UT (78.52 ± 5.43 °C) study groups (p < 0.001). The drilling technique without irrigation provides a less removal capability, less conical internal hex implant-abutment connection damage and less thermal effect than ultrasonic technique for the extraction of fractured abutment screws; however, the ultrasonic technique resulted more effective for the extraction of fractured abutment screws.

In Vitro Analysis of the Removability of Fractured Prosthetic Screws within Endosseous Implants Using Conventional and Mechanical Techniques

“…Finally, the extraction rate in the mobile abutment screws was 93.1% and in the fixed abutment screws was 51.9%; however, Agustín-Panadero et al did not differentiate whether the fragment was mobile or not [15]. In addition, the results of the present study do not agree with those obtained by Bufalá Pérez et al, since they reported that the drilling technique without irrigation provides a lesser removal capability, less conical internal hex implant-abutment connection damage, and less thermal effect than the ultrasonic technique for the extraction of fractured abutment screws; however, the ultrasonic technique was more effective for the extraction of fractured abutment screws [29].…”

“…Regarding the mechanical or specific extraction systems, they achieve better results in the recovery of the screw fragments, recovery time, and preservation of the internal thread of the implants [18][19][20][21][22][23][24][25][26][27][28][29]. The conventional method in which a probe and ultrasound are used is efficient as well as economical; therefore, it is a good method for the extraction of fractured abutment screws and this is supported by the statistical data found in the different studies that have a 73.3% extraction success with this method [12,15].…”

Effect of different parameters utilized for image guided endodontic root canal preparation on temperature changes: an in vitro study

“…During guided endodontic drilling, heat is first transferred to the nonvital structure of dentine and only secondarily to bone. In this regard, preparation in the root canal is more similar to broken abutment screw removal from dental implants [ 13 ]. However, conclusions derived from these studies cannot be directly applied to guided endodontics for two main reasons.…”