Comparison of four methods that remove calcium hydroxide from root canals / 口腔疾病防治

Objective@# To compare the efficiency of four methods that remove calcium hydroxide in root canals and to guide clinical practice. @* Methods @# Sixty-five isolated mandibular single root canal premolars were collected. After crown cutting and root canal preparation, a tooth was randomly selected as the blank control group, and the remaining 64 teeth were equally divided into Groups A and B (n = 32). Group A was injected with water-soluble calcium hydroxide, and Group B was injected with oil-soluble calcium hydroxide. After 2 weeks of drug sealing, Groups A and B were randomly divided into 4 groups (n = 8), including the lateral opening syringe group, sonic vibration group, ultrasonic group, and Er: YAG laser group. Before and after calcium hydroxide removal, the samples were scanned by cone-beam CT, and the data were imported into Mimics for 3D reconstruction. The root canal was divided into the following segments: superior root segment, middle and apical, and the calcium hydroxide volume of each segment of the root canal was calculated. The volumes of calcium hydroxide before and after removal were V1 and V2, respectively, with a clearance rate = (V1-V2)/V1×100%. Three-factor ANOVA was used for statistical analysis. After Groups A and B were reconstructed, the apical region with residual calcium hydroxide was selected, and the blank control was observed by scanning electron microscopy (SEM). @*Results @# Two types of calcium hydroxide could not be completely removed by the four flushing methods. The clearance rate of water-soluble calcium hydroxide was higher than that of oil-soluble calcium hydroxide (P<0.001). Among the three segments of the root canal, the clearance rate of the apical segment was lower (P<0.05). The Er: YAG laser treatment group showed the highest removal efficiency of two kinds of calcium hydroxide, which was higher than that of the other groups, especially in apical of the root. Compared with the sonic wave washing group and the syringe washing group, the ultrasonic wave washing group exhibited significant advantages (P<0.05). The clearance rate of the sonic wave washing group was higher in the oily calcium hydroxide root middle group than in the syringe washing group (P<0.05). SEM showed that the two kinds of calcium hydroxide could not be completely removed, but the residual rate of oil-soluble calcium hydroxide was large.@*Conclusion @# Both types of calcium hydroxide could not be completely removed, and compared to water-soluble calcium hydroxide, oil-soluble calcium hydroxide was more difficult to remove. Among the four cleaning methods, Er:YAG laser swing washing showed the higher cleaning efficiency.

Research on effectiveness evaluation and analysis equipment derusting for ultrasonic cleaning machine / 中国医学装备

Objective:To investigate the ultrasonic cleaning machine in the equipment derusting effect of.Methods: Rusty instrument as rust 600, were randomly divided into two groups, experimental group (n=305) and control group (n=295). The first device in according to 1:270 proportion of organic pollutants in multi enzyme cleaning solution good, the experimental group will rust instrument containing stainless steel basket, in according to the proportion of 1:7(water temperature is 60℃) ultrasonic cleaning machine solution rust agent by ultrasound in 10 minutes, with a soft brush to wash; the control group will instrument in the water temperature in 60℃, solution rust agent 1:7 mixing ratio, non constant temperature for 10 minutes using a soft bristle brush. Observe and record the two rust rust indicators, and analysis.Results: The naked eye visual two groups of instruments derusting pass rate was not statistically significant (P<0.05); microscopy (5 times the magnifying glass) experimental group equipment derusting pass rate was significantly higher than that of the control group, there were significant difference between two groups (P<0.001); total flexibility in experimental group was significantly better than the instruments the control group, there were significant difference between two groups (P<0.001).Conclusion: The rusty instrument in a constant temperature of 60℃ plus ultrasonic cleaning descaling effect, improves the equipment clean quality and overall flexibility.

Microscopical and chemical surface characterization of CAD/CAM zircona abutments after different cleaning procedures. A qualitative analysis

PURPOSE: To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS: A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non-quantitatively. RESULTS: All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION: The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.

Microscopical and chemical surface characterization of CAD/CAM zircona abutments after different cleaning procedures. A qualitative analysis

PURPOSE: To describe and characterize the surface topography and cleanliness of CAD/CAM manufactured zirconia abutments after steaming and ultrasonic cleaning. MATERIALS AND METHODS: A total of 12 ceramic CAD/CAM implant abutments of various manufacturers were produced and randomly divided into two groups of six samples each (control and test group). Four two-piece hybrid abutments and two one-piece abutments made of zirconium-dioxide were assessed per each group. In the control group, cleaning by steam was performed. The test group underwent an ultrasonic cleaning procedure with acetone, ethyl alcohol and antibacterial solution. Groups were subjected to scanning electron microscope (SEM) analysis and Energy-dispersive X-ray spectroscopy (EDX) to verify and characterize contaminant chemical characterization non-quantitatively. RESULTS: All zirconia CAD/CAM abutments in the present study displayed production-induced wear particles, debris as well as organic and inorganic contaminants. The abutments of the test group showed reduction of surface contamination after undergoing an ultrasonic cleaning procedure. However, an absolute removal of pollutants could not be achieved. CONCLUSION: The presence of debris on the transmucosal surface of CAD/CAM zirconia abutments of various manufacturers was confirmed. Within the limits of the study design, the results suggest that a defined ultrasonic cleaning process can be advantageously employed to reduce such debris, thus, supposedly enhancing soft tissue healing. Although the adverse long-term influence of abutment contamination on the biological stability of peri-implant tissues has been evidenced, a standardized and validated polishing and cleaning protocol still has to be implemented.

Influence of ultrasonic cleaning time and disinfecting frequency on physical property of Ni- Ti root canal files / 中国实用护理杂志

Objective To investigate the influence of ultrasonic cleaning time and disinfecting frequency on physical property of Ni-Ti root canal files in order to understand the safety and feasibility of ultrasonic cleaning and high temperature and high pressure disinfection for Ni-Ti root canal files.Methods The Ni-Ti root canal files used in this study were ProTaper,Mtwo and Hero642,5 files were selected from each kind.After the ultrasonic cleaning and high temperature high pressure disinfection the files underwent breaking test,the breaking time was recorded.Unclean and non-sterile Ni-Ti root canal files were set as control.Results After different time of ultrasonic cleaning,ProTaper and Mtwo showed no difference in breaking time,but the result was opposite in Hero642.After different times of disinfection,Mtwo showed no difference in breaking time,but significant difference was seen in the other two kinds.Conclusions Ultrasonic cleaning time has no significant influence on physical property of ProTaper and Mtwo Ni- Ti root canal files,but the influence was significant for Hero642.Disinfection frequency had no significant influence on physical property of ProTaper and Hero642 Ni-Ti root canal files,but the influence was significant for Mtwo Ni-Ti root canal files.

Research of the influential factors of ultrasonic cleaning of curettage- aspiration device for uterine cavity / 中国实用护理杂志

Objective To evaluate the combination influence of the factors such as the ways to putting into the water, addition with multienzyme and temperature of water on the cleaning effect of ultrasonic cleaning of the curettage-aspiration device for uterine cavity. So that we can find out the best condition for cleaning, and provide the scientific evidence for the formulation of the norm of ultrasonic cleaning of the curettage-aspiration device for uterine cavity. Methods According to the factorial design with triple pathogens, three factors were chosen to complete the ultrasonic cleaning of the curettage-aspiration device for uterine cavity, including the sequence of putting into water, addition with multienzyme or not and the temperature of cleaning. The cleaning effect was detected by adopting the eye-measurement or with the hemoglobin reagent. Results The sequence of putting into water first or next had little influence on ultrasonic cleaning;the effect of addition with multienzyme was more significant than without it;the effect of water temperature at 35 centi-degree or 40 centi-degree had no difference. Conclusions It had good benefits for the cleaning effect when the ultrasonic cleaning of the curettage-aspiration device for uterine cavity added multienzyme to the cleansing solution, while the sequence of putting into water first or next and the temperature of water at 35 centi-degree or 40centi-degree shows little influence on the cleaning effect.