Search Results (3)

Achieving negative surgical margins, defined as no tumor found on the edges of the resected tissue, during lumpectomy for breast cancer is critical for mitigating the risk of local recurrence. To identify nonpalpable tumors that cannot be felt, pre-operative placements of wire and wire-free localization devices are typically employed. Wire-free localization approaches have significant practical advantages over wired techniques. In this study, we introduce an innovative localization system comprising a light-emitting diode (LED)-based implantable device and handheld system. The device, which is needle injectable and wire free, utilizes multiple wirelessly powered LEDs to provide direct visual guidance for lumpectomy. Two distinct colors, red and blue, provide a clear indication of tissue depth: blue light is absorbed strongly in tissue, visible within a close range of <1 cm, while red light remains visible through several centimeters of tissue. The LEDs, integrated with an impedance-matching circuit and receiver coil, are encapsulated in biocompatible epoxy for injection with a 12 G needle. Our findings demonstrate that the implant exhibits clearly perceivable depth-dependent color changes and remains visible through >2 cm of ex vivo chicken breast and bovine muscle tissue using less than 4 W of transmitted power from a handheld antenna. These miniaturized needle-injectable localization devices show promise for improving surgical guidance of nonpalpable breast tumors. Full article

Background: The objective of the present study was to measure and compare how the length of CM Gold Wire and CM Blue Wire NiTi alloy endodontic rotary files impacts their resistance to cyclic fatigue. Methods: A total of 40 sterile endodontic rotary files were chosen and allocated to the following study groups: (A) 25.06 CM Gold wire NiTi alloy endodontic rotary files, 31 mm in length (n = 10); (B) 25.06 CM Gold wire NiTi alloy endodontic rotary files, 25 mm in length (n = 10); (C) 25.06 CM Gold wire NiTi alloy endodontic rotary files, 21 mm in length (n = 10); and (D) 25.06 CM Blue wire NiTi alloy endodontic rotary files, 17 mm in length (n = 10). A specialized device was designed using artificial root canal systems made from stainless steel for the dynamic cyclic fatigue tests, with an apical diameter of 250 µm, curvature angle of 60°, radius of curvature of 5 mm, lengths of 31, 25, 21, and 17 mm, and a 6% taper. An individual operator determined failure of the endodontic rotary instrument through direct observation and the tests were filmed so as to precisely measure the exact time to failure. The results were analyzed using ANOVA and Weibull statistical analysis. Results: The results found statistically significant differences across all study groups (p < 0.05). Conclusions: Rotary file length is inversely proportional to the cyclic fatigue resistance of the 25.06 CM Gold wire NiTi alloy at 31 mm, 25 mm, and 21 mm in length and of the 25.06 CM Blue wire NiTi alloy 17 mm length endodontic rotary files, with a greater length contributing to lower resistance to cyclic fatigue. Full article

Background: The aim of this study was to analyze the influence of NiTi alloy in endodontic rotary instruments on cyclic fatigue resistance. Methods: One hundred and sixty-four (164) sterile endodontic rotary files were selected and distributed into the following study groups: A: 25.08 F2 ProTaper Universal (PTU) (n = 41); B: 25.06 X2 ProTaper Next (PTN) (n = 41); C: 25.08 F2 ProTaper Gold (PTG) (n = 41), and D: 25.06 ProFile Vortex Blue (PVB) (n = 41). A cyclic fatigue device was designed to conduct the static cyclic fatigue tests with stainless steel artificial root canals systems with 250 µm apical diameter, 60° curvature angle, 5 mm radius of curvature, 20 mm length, and 6% (25.06) and 8% taper (25.08). Failure of the endodontic rotary instrument was detected by a single operator through direct observation and was also filmed to allow measurement of the exact time to failure. Results were analyzed using the ANOVA test and Weibull statistical analysis. Results: All pairwise comparisons presented statistically significant differences between the time to failure for the NiTi alloy study groups (p < 0.001), except between the PTN and PVB study groups (p = 0.379). In addition, statistically significant differences between the number of cycles to failure for the NiTi alloy study groups (p < 0.001) were also observed. Conclusions: The NiTi CM-Gold wire alloy of the ProTaper Gold endodontic rotary files resulted in greater resistance to cyclic fatigue than ProFile Vortex Blue, ProTaper Next, and ProTaper Universal endodontic rotary files. Full article