جستجوی مقالات مرتبط با کلیدواژه "dental burs" در نشریات گروه "پزشکی"

 The methods of increasing the longevity of dental burs by improving the mechanical properties of these surfaces, can increase their longevity. This study assessed the effect of diamond-like carbon (DLC) coating applied by the physical vapor deposition (PVD) technique on wear of diamond and tungsten carbide (TC) burs.

 In this in vitro study, 30 diamond and 30 TC burs were evaluated in four groups, including TC burs without coating (control), TC burs with a 3.5-µm DLC coating applied by the PVD technique, diamond burs without coating (control), and diamond burs with a 3.5-µm DLC coating applied by the PVD technique. The burs were weighed by a digital scale, underwent the pin-on-disc wear test, and were weighed again. The weight loss indicated the degree of wear in each group. For qualitative assessments, the surface of the burs was inspected under a stereomicroscope at×4 and×10 magnifications before wear, halfway through the test, and after the test. Finally, the data were analyzed by two-way ANOVA (α=0.05).

 The effect of DLC coating was significant on the wear of burs (P=0.032), but the effect of the type of bur and their interaction effect on wear were not significant (P=0.151). A significant difference existed in wear among the four groups (P < 0.001), and the wear of coated burs was significantly lower than that of non-coated burs (P=0.012). Stereomicroscopic assessments revealed some residual diamond particles, the impression of dislodged particles and the path of wear on the surface of diamond burs, and the path of wear on the surface of TC burs.

 Overall, the DLC coating of diamond and TC dental burs by the PVD technique could increase their wear resistance irrespective of the bur type.

Dental burs are among the most commonly used instruments in dental offices and have the most possible cross-contamination risks. The sterilization of dental burs is highly noted and necessary. The present study evaluated the effects of different sterilization methods on the uniformity of diamond dental burs and changes in the cutting edge carbide burs. In this descriptive study, to assess the results of sterilization, 36 burs (18 diamond burs and 18 carbide burs) were studied. In total, 18 diamond burs using R software were randomly divided into the 3 groups of 6 burs (dry-clave group, autoclave group, and cold sterilization group). Each group was divided into the 2 subgroups of 3 burs; the first subgroup received 5 cycles and the second subgroup received 15 cycles of sterilization. The same process was used for 18 carbide burs to categorize them into groups and subgroups. A pre-assessment was conducted by Scanning Electron Microscopy (SEM). After the sterilization cycles, a post-test SEM was performed. Adobe Photoshop 2017 was used in a gray scale of 12 to compare the pre-test and post-test differences. Kruskal-Wallis test, Analysis of Variance, Mann-Whitney U test, and Post Hoc Tukey test were used to analyze the obtained data in SPSS at a significance level of P=0.05. Dry-clave was the best approach in 5 cycles of sterilization for diamond and carbide burs. Moreover, autoclave was the best method for 5 cycles of sterilization (P<0.05). In 15 cycles of sterilization of diamond and carbide burs, the best method was auto-clave which exhibited a significant difference in carbide burs. Dry-clave and autoclave were the most appropriate approaches for 5 and 15 cycles of sterilization of diamond burs, respectively. In sterilization of carbide, in both 5 and 15 cycles, autoclave was the best method. All of the sterilization methods caused corrosion, discoloration, and the loss of integrity in carbide burs; however, these changes were minimum in the autoclave method. In conclusion, auto-clave method is recommended due to causing the least changes in carbide and diamond burs.