[Precision evaluation of retention and adaptation in robotically fabricated wrought wire clasps for removable...

Objective: To explore the application of dental wire bending robots in the fabrication of dual arm clasps, to observe and analyze the retention force and sealing performance of clasps, and to provide scientific basis for clinical application promotion. Methods: A mandibular first molar from a teaching model was selected. Dental stainless steel wire was used to fabricate two groups of double arm clasps (n=10). The experimental group used a robot to bend the clasps, while the control group were made manually by a dental technician. A removable denture retention force measurement system was used to measure the initial retention force values of two groups of claps, and independent-samples t-test was used to analyze the results. The adaption performance of two groups clasps (buccal clasp tip, clasp arm, proximal axial angle of the clasp shoulder, lingual clasp tip, clasp arm, and the proximal axial angle of the clasp shoulder) was measured and compared using the silicone rubber film method. Results: The dental wire bending robot successfully completed the automatic processing of the dual arm clasp in the experimental group according to the design requirements, and its clasp retention force value [(1.58±0.15) N] was significantly higher than that of the clasps in the control group [(0.92±0.28) N] (t=-6.39, P<0.001). The adaption performances of the retention arm body [(95.84±62.11) μm] and the opposing arm tip [(116.79±21.39) μm] of the experimental group are better than that of the control group clasps [(241.30±104.80), (261.87±89.27) μm] (t=-3.78, P<0.001; t=-4.98, P<0.001), and there was no statistical difference in the sealing performance of the two at other measurement points (all P>0.05). Conclusions: The retention force and adaption of the dental robotic bending clasp are superior to traditional manual methods, and it is expected to be used in clinical practice to improve the digital processing level of removable dentures.