Three-dimensional Change of Elastomeric Impression Materials During the First 24 Hours: A Pilot Study

SUMMARY Objectives: To evaluate the three-dimensional (3D) changes of three elastomeric impression materials using a novel measurement method for the first 24 hours after preparation. Methods and Materials: Three impression materials consisting of a low-viscosity polyvinyl siloxane (PVS) (Aquasil LV, Dentsply Sirona, Charlotte, NC, USA) and two vinyl polyether silicone (VPES) materials consisting of a light body (EXA’lence LB, GC America, Alsip, IL, USA) and monophase (EXA’lence Monophase, GC America) materials were used in this study. All materials were prepared following manufacturer’s recommendations with approximately 1–2 millimeters of material placed on the measurement pedestal of a calibrated noncontact, video imaging based, volumetric change measuring device (AcuVol ver 2.5.9, Bisco, Schaumburg, IL, USA). Data collection was initiated immediately, with measurements made every 30 seconds for 24 hours. Each material was evaluated 10 times (n=10). Evaluated parameters included were 24-hour mean shrinkage, mean shrinkage at time of recommended first pour, mean shrinkage between recommended first pour and 24 hours, mean maximum shrinkage, and the time of maximum shrinkage. Mean data, both within and between each group, was evaluated using Kruskal–Wallis/Dunn’s tests at a 95% level of confidence (α=0.05). Results: All three materials were found to have significant differences (p<0.001) in volumetric shrinkage over 24 hours. Aquasil LV and EXA’lence LB polymerization shrinkage rates were statistically similar all through the 24-hour evaluation (p=0.92). All three materials demonstrated similar (p=0.19) shrinkage between 10 and 15 minutes after preparation, while between 5 and 16 hours both EXA’lence Monophase and low-viscosity materials demonstrated similar polymerization shrinkage values (p=0.22). EXA’lence Monophase demonstrated significantly greater 24-hour mean shrinkage (p<0.008) as well as shrinkage between recommended first pour time and 24 hours (p=0.003) than Aquasil LV and EXA’lence LB. EXA’lence Monophase demonstrated significantly greater (p=0.002) shrinkage at the recommended time of first pour as compared to Aquasil LV and EXA’lence LB that displayed similar shrinkage (p=0.89). Furthermore, all materials demonstrated increasing polymerization shrinkage values that reached a maximum between 16 for Aquasil LV and 20 hours for EXA’lence LB, after which some relaxation behavior was observed. However, EXA’lence Monophase did not display any relaxation behavior over the 24-hour evaluation. Conclusions: Under the conditions of this study, volumetric polymerization shrinkage was observed for one polyvinyl siloxane (PVS) and two vinyl polyether silicone (VPES) materials for up to 24 hours. All impression materials exhibited fast early volumetric shrinkage that continued past the manufacturer’s recommended removal time. Dimensional change behavior was not uniform within or between groups; resultant volume change between the manufacturer recommended pouring time and 24 hours might represent up to from 20% to 30% of the total material shrinkage. It may be prudent to pour elastomeric impressions at the earliest time possible following the manufacturer’s recommendations.

Removing of Cadmium Ions and Reactive red Dye from Simulated Wastewater Using Eggshell as an Eco-Friendly Material

The research aims to use eggshells (ES) as civilian residues in the process of removing cadmium ions and reactive red dye according to international standards limits. Synthetic solutions were prepared for cadmium ions and reactive red dye using 0.2 g non-calcined and calcined ES at various temperatures (25, 250, 500, 750, and 1000 ℃) as an adsorbent. The result showed the removal of cadmium ion was (60, 100%) for non-calcined and calcined ES, respectively, with the initial concentration of cd2+ (10 ppm). The removal of reactive red dye was (18.5, 98%) using non-calcined and calcined ES, respectively, at a concentration of red dye (50 ppm). The best removal time was 90 min. XRD and FTIR spectroscopy were performed and the results were identical to the main components of ES and changed with temperature increasing due to dissolution of calcium carbonate (CaCO3).

The Impact of Catheter Removal Time on Urinary Continence and Overactive Bladder Symptoms After Robot-Assisted Radical Prostatectomy: A Retrospective Analysis of Consecutive 250 Cases From a Single Institution

Background After radical prostatectomy, the optimal length of postoperative catheterization time remains to be determined. This study investigates the impact of catheter removal time on urinary continence and overactive bladder symptoms after robot-assisted radical prostatectomy (RARP).Methods Two hundred and fifty consecutive patients underwent RARP by a single surgeon between November 2020 and May 2021. Time to catheter removal was categorized into 7, 10, and ≥ 14 days. Continence was defined as no more than 1 pad used or no more than 20 grams of urine leakage per 24 hours. The patients' continence rates and overactive bladder symptom score (OABSS) were assessed at 48 hours, 1 week, 4 weeks, 12 weeks, and 24 weeks after catheter removal.Results Overall, continence rates were 36% 48 hours after catheter removal, 55.6% 1 week, 74.8% 4 weeks, 98.4% 12 weeks, and 100% 24 weeks after catheter removal. The median time to regain continence was 1 week. After stratification according to catheterization time, no significant difference in continence rates was found between different groups at each time point after catheter removal. Longer catheterization was not an independent predictor of continence recovery (10 days: OR 0.985, 95% CI 0.689-1.409, p = 0.936; ≥14 days: OR 1.194, 95% CI 0.869-1.642, p = 0.274). The presence of diabetes was associated with worse continence outcomes (OR 1.535, 95% CI 1.105-2.132, p = 0.011). The mean OABSS of patients in the continent group were significantly lower than the incontinent group at 48 hours, 1 week, and 4 weeks after catheter removal. No significant difference in OABSS was found between different catheterization time groups at each time point after catheter removal.Conclusions Our results demonstrated that different catheterization time (7 days, 10 days, ≥14 days) is not associated with short-, intermediate-, long-term continence outcomes or overactive bladder symptoms.

Risk of leakage with a new tissue containment system for power morcellation during gynecologic laparoscopy: An in vitro study

Purpose To evaluate leakage and tissue dissemination associated with a new tissue containment system for tissue removal during laparoscopic myomectomy morcellation using rigid pipes that can be seamlessly connected to detachable trocars. Methods Pork specimens were stained with indigo carmine dye and morcellated under laparoscopic guidance in a plastic trainer box. Morcellation was performed using two different containment systems. First, a polyurethane bag, 12 mm sheath for introduction into the peritoneal cavity, and 11 mm optic sleeve (control group). Second, a new tissue containment system using rigid pipes and detachable trocars (experimental group). All bags were inflated to 14–20 mmHg pressure using a standard CO2 insufflator. Visual evidence of spilled tissue or dye and procedure times were recorded. Results Thirty trials were performed using a multi-port approach and the two tissue containment systems. The leakage rate was 0.03% for the experimental group and 26.6% for the control group (p < 0.005). Morcellation time was significantly shorter in the experimental group compared to that in the control group (p < 0.05). Mean bag introduction and removal times of the experimental group were shorter than those of the control group; however, the removal time differences were not statistically significant. Conclusion The current study quantified leakage during morcellation and the convenience provided by a new tissue containment system. Further studies and clinical trials are needed to corroborate the findings and to evaluate the use of the new tissue containment system for minimally invasive surgical treatment of tumors.

White-opaque flowable composite liner as a depth marker in composite restorations prevents tooth substance loss in filling removal: a randomized double-blinded in vitro study

Objectives Removal of esthetic restorations leads to loss of tooth structure and the extent of the loss is difficult to estimate due to exact-shade matching. This randomized double-blinded in vitro study aimed examining the influence of a white-opaque flowable composite depth marker as an optical removal aid for tooth substance preservation and shortened restoration removal time. Materials and methods Class II cavities (n = 100) in extracted healthy mandibular molars (n = 50, two runs) were prepared, filled, and the restoration removed. Tooth weight and volume (before and after) and removal time were measured and remnants visually documented. An optimal tooth shade-matched flowable composite liner was used as control. Results Tooth structure loss was significantly lower using a white-opaque liner. Mean values for volume/weight loss were 0.037 ± 0.030 g and 0.016 ± 0.005 cm3 (p < 0.01) for white-opaque liner; 0.067 ± 0.000 g and 0.028 ± 0.003 cm3 (p < 0.01) for tooth-colored composite. Removal time and number of pulp chamber perforations showed no significant differences (p = 0.80). Conclusions Within the limitations of this randomized double-blinded in vitro study, the use of a white-opaque flowable liner as a depth marker may provide the practitioner a visual aid in the replacement of a composite restoration and may protect against tooth structure loss. Clinical relevance When restoration replacement is indicated, removal of esthetic restorations often causes tooth structure loss due to difficult optical color matching. Using a white-opaque flowable liner as a depth marker clinically aids in restoration removal and protects against tooth structure loss.

Performance Evaluation of Different Combined Drainage Forms on Flooding and Waterlogging Removal

Farmland in southern China is prone to flooding and waterlogging alternation after short-term heavy rainfall. Single drainage form cannot meet the requirements of the farmland flooding and waterlogging removal. Drainage measures and layout forms should be explored to alleviate flooding and waterlogging threat and improve crop yield. So, based on an indoor sand tank experiment, this paper presents a combined drainage form: conventional subsurface drainage as an auxiliary drainage measure and is alternatively combined with open ditch (OD), filter drainage (FD), conventional (CD) and improved subsurface drainage (ID), respectively, under equal and unequal drain depth. The performance of different combined drainage forms and the effect of auxiliary drainage measures are discussed for stable ponding and receding water. During the experiment, two factors—drainage measure and drain depth—are considered. The results indicate that compared with the conventional subsurface drainage alone, the flow rates of the open-ditch, thin-improved, and thick-improved subsurface drainage combined with conventional subsurface drainage can be increased by 22.4–32.3%, 10.6–16.2%, and 29.8–32%, respectively, under equal drain depth in stable ponding water. Among the four combined drainage forms, the flow rate of shallow–deep combination is 8.1–17.1% higher than that of the shallow–shallow combination. Compared with a single drainage form, the flow rates of the combined drainage have the same change characteristics over time. Additionally, the use of auxiliary, conventional, subsurface drainage can improve the flooding and waterlogging removal efficiency in farmland. For the combined drainage forms, the contribution degree of the open-ditch and thin-improved subsurface drainage is 51.3–56.7%, while the thick-improved subsurface drainage is approximately 61.0%, under equal drain depth conditions in the flooding removal process. Moreover, open-ditch and thick-improved subsurface drainage combined with conventional subsurface drainage have significant advantages in flooding and waterlogging removal, which were 11.5–38.1% and 37.1–48.6% faster than conventional subsurface drainage in flooding removal time, 14.3–157.1% and 14.3–44.4% faster than conventional subsurface drainage in the waterlogging removal time. The synergistic application of shallow–deep and medium–medium combinations can be carried out by exploiting the advantages of each drainage measure. The experimental flow rate observation is in good agreement with the theoretically calculated value, with a relative error of less than 5%. These research findings could provide technical support for the increased application of combined drainage forms in areas prone to flooding and waterlogging.

Risk Factors and Management Strategies of Cerebrospinal Fluid Leakage Following Lumbar Posterior Surgery

Objective: To analyze the risk factors of cerebrospinal fluid leakage(CSFL) following lumbar posterior surgery and summarize the related management strategies. Methods: A retrospective analysis was performed on 3179 patients with CSFL strategies lumbar posterior surgery in our hospital from January 2019 to December 2020. There were 807 cases of lumbar disc hemiation(LDH), 1143 cases of lumbar spinal stenosi (LSS), 1122 cases of lumbar spondylolisthesis(LS), 93 cases of lumbar degenerative scoliosis(LDS),14 cases of lumbar spinal benign tumor(LST). Data of gender, age, body mass index(BMI), duration of disease, diabete,smoking history, preoperative epidural hormone injection, number of surgical levels, surgical methods (total laminar decompression, fenestration decompression), revision surgery, extubation time, suture removal time, and complications were recorded.Results: The incidence of 115 cases with cerebrospinal fluid leakage,was 3.62% (115/3179).One-way ANOVA showed that gender, body mass index(BMI), smoking history, combined with type 2 diabetes and surgical method had no significant effect on CSFL(P >0.05). Age, type of disease, duration of disease, preoperative epidural hormone injection, number of surgical levels and revision surgery had effects on CSFL(P<0.05). Multivariate Logistic regression analysis showed that type of disease, preoperative epidural hormone injection, number of surgical levels and revision surgery were significantly affected CSFL(P<0.05), and duration of disease and age of the patients were not significantly affected CSFL (P >0.05).The extubation time of CSFL patients ranged from 7 to 11 days, with an average of 7.11±0.48 days, the extubation time of patients without CSFL was 1-3 days, with an average of 2.02±0.13 days, and there was a statistical difference between the two groups(P < 0.05).The removal time of CSFL patients was 12-14 days, with an average of 13.11±2.67 days, and the removal time of patients without CSFL was 10-14 days, with an average of 12.87±2.19 days, there was no statistically significant difference between the two groups (P>0.05). Conclusion: Type of disease, preoperative epidural hormone injection, number of surgical levels and revision surgery were the risk factors for CSFL. Effective prevention were the key to CSFL in lumbar surgery.Once appear, CSFL can also be effectively dealt with without obvious adverse reactions after intraoperative effectively repair dural, head down, adequate drainage after operation, the high position, rehydration treatment, and other treatments.

Factors Affecting Synthetic Dye Adsorption; Desorption Studies: A Review of Results from the Last Five Years (2017–2021)

The primary, most obvious parameter indicating water quality is the color of the water. Not only can it be aesthetically disturbing, but it can also be an indicator of contamination. Clean, high-quality water is a valuable, essential asset. Of the available technologies for removing dyes, adsorption is the most used method due to its ease of use, cost-effectiveness, and high efficiency. The adsorption process is influenced by several parameters, which are the basis of all laboratories researching the optimum conditions. The main objective of this review is to provide up-to-date information on the most studied influencing factors. The effects of initial dye concentration, pH, adsorbent dosage, particle size and temperature are illustrated through examples from the last five years (2017–2021) of research. Moreover, general trends are drawn based on these findings. The removal time ranged from 5 min to 36 h (E = 100% was achieved within 5–60 min). In addition, nearly 80% efficiency can be achieved with just 0.05 g of adsorbent. It is important to reduce adsorbent particle size (with Φ decrease E = 8–99%). Among the dyes analyzed in this paper, Methylene Blue, Congo Red, Malachite Green, Crystal Violet were the most frequently studied. Our conclusions are based on previously published literature.

In Situ Measurement of Airborne Particle Concentration in a Real Dental Office: Implications for Disease Transmission

Aerosols generated during dental procedures are one of the most significant routes for infection transmission and are particularly relevant now in the context of COVID-19 pandemic. This study aimed to assess the effectiveness of an indoor air purifier on dental aerosol dispersion in dental offices. The spread and removal of aerosol particles generated from a specific dental operation in a dental office are quantified for a single dental activity in the area near the generation and corner of the office. The effects of the air purifier, door condition, and particle sizes on the spread and removal of particles were investigated. The results show that, in the worst-case scenario, it takes 95 min for 0.5-μm particles to settle and that it takes a shorter time for the larger particles. The air purifier expedited the removal time at least 6.3 times faster than the case with no air purifier in the generation zone. Our results also indicate that particles may be transported from the source to the rest of the room even when the particle concentrations in the generation zone dropped back to the background. Therefore, it is inaccurate to conclude that indoor purifiers help reduce the transmission of COVID-19. Dental offices still need other methods to reduce the transmission of viruses.