Culture medium and protein supplementation affect sensitivity of the mouse embryo assay in detecting Triton X-100.

RESEARCH QUESTION: To what extent does the type and concentration of protein and the type of culture medium affect the sensitivity of the mouse embryo assay (MEA) to detect Triton X-100 (TX-100) in culture media? DESIGN: The effect of the concentration of bovine serum albumin (BSA) and human serum albumin (HSA) was assessed by supplementing media with 0.5 or 5 mg/ml. Potassium-supplemented simplex optimized medium (KSOM) and human tubal fluid (HTF) were used as complex and simple formulation media, respectively. Variables were combined, forming study groups where embryos were cultured in test media spiked with a sublethal TX-100 concentration. The conditions of greatest sensitivity were determined by statistical comparison of blastocyst formation rates and total cell counts between groups. RESULTS: Although all of the study groups showed equal capacity for sustaining proper embryo development, the reported sensitivity of the MEA differed between groups when subjected to TX-100. HTF conferred significantly greater sensitivity than KSOM regardless of the type and concentration of protein used, and medium supplementation with 5 mg/ml BSA rather than 0.5 mg/ml BSA resulted in significantly higher sensitivity regardless of the type of medium used. This increase in concentration also resulted in higher sensitivity when supplementing HTF with HSA. The BSA groups provided more sensitivity than their HSA counterparts, except for the KSOM + 0.5 mg/ml BSA group. Cell count analysis did not provide further significant conclusions. CONCLUSIONS: For TX-100 detection within culture medium, the type and concentration of protein and the type of culture medium have a direct effect on MEA sensitivity. These results could help to standardize the MEA protocol, and increase its ability to detect sublethal concentrations of embryotoxic substances, especially TX-100, thus avoiding possible clinical harmful effects.

Comparative evaluation of two cetylpyridinium chloride-based mouthwashes on the mechanical properties and strength loss of elastomeric chains used in dentistry: An vitro study.

Objectives: Evaluate the strength degradation of polymeric ligature chains after their immersion in cetylpyridinium chloride-based mouthwashes. Methods: 240 elastomeric samples from four different manufacturers (Rocky Mountain®, Ormco®, Morelli® and Dentaurum®) in two types of configurations (with and without intermodular links) and divided in 3 groups (distilled water, Vitis CPC Protect® and PERIO·AID® 0.05%) at 5 follow-up periods (0-24 h, 7-14 -21 days) were immersed twice a day for 60 s, following the manufacturers' protocols. A universal traction machine was used to perform the measurements and a post hoc multiple comparisons were based on the Bonferroni test and extended to a 3-way ANOVA test (α = 0.05). Results: There was a drop in strength up to 35.9% at 24 h. After a week, the short chains (52%) degraded less than the long ones (57.3%) with significant differences (p < 0.001) and the same pattern was observed until 21 days (p < 0.001). At 24 h, the degradation of the chains exposed in distilled water was 25.8%, in VITIS CPC Protect® 28.6% and in PERIO· AID® 0.05%, 27% with significant differences (p < 0.001). At 21 days, the VITIS CPC Protect® group obtained a much greater loss of strength, being this drop statistically significant (p < 0.001). The chains from Ormco® and RMO® experienced the least loss of force when immersed in the control group or PERIO AID® 0 0.05% (48% and 51%), while Dentaurum's in VITIS CPC Protect® lost more than 75%. Conclusions: The orthodontic elastomeric chains suffer a sharp drop in strength during the first days of treatment. When comparing the mouthwashes, there were statistically significant differences in terms of strength degradation. Clinical significance: Based on the results, some types of chains, such as the ones without intermodular links from Ormco® showed better properties throughout the study. When immersed in PERIO·AID®0.05%, all showed significantly better results over time. Thus, PERIO·AID®0.05% can be recommended as a complementary oral hygiene element in dental treatments when elastomeric chains are used.

Effect of mouthwashes on the force decay of polymeric ligature chains used for dental purposes: a systematic review and meta-analysis.

BACKGROUND: External factors such as the daily use of antimicrobial mouthwashes to maintain oral hygiene and to reduce the microbial activity can contribute to alter the mechanical properties of the elastomeric chains used during orthodontic treatments, causing loss of effectiveness. This systematic review and a meta-analysis assessed the rate of force decay and degradation of the polymeric chains depending on the type of mouthwash. METHODS: A systematic search of the literature were there was an exposure of orthodontic elastomeric chains to certain mouthwashes was conducted in the electronic databases of PubMed, Cochrane Library (CENTRAL), Scopus, EMBASE and Web of Science, as well as grey literature (Opengrey). No limit was placed on publication year and research was done up to June 2022. Based on inclusion/ exclusion criteria, data were extracted by two independent reviewers. For the quantitative analysis, studies were analysed with a mixed-effect (random effect) meta-regression model, with beta coefficients and R [2] values. I [2] index and Q and Egger tests were used to find heterogeneity among studies. RESULTS: A total of 178 potentially eligible studies were identified, of which 14 were eventually included in the qualitative analysis and 14 in the quantitative meta-analysis. The meta-analysis showed that all the mouthwashes were associated with a greater force decay than the control groups. After 7 days (p = 0.005) significant differences were found among the different mouthwashes, with those containing alcohol having significantly higher impact on the force decay than those containing chlorhexidine 0.2%, sodium fluoride or Persica. However, at 24 h (p = 0.200), 14 days (p = 0.076), 21 days (p = 0.120) and 28 days (p = 0.778) no statistically significant differences among the different mouthwashes were found, although those containing alcohol presented a strong tendency. CONCLUSION: Although mouthwashes tend to increase the speed of force decay of elastomeric chains, especially those containing alcohol, clorhexidine 0.2% can be a good alternative due to its low impact on the force decay and its ability to maintain low microbial activity. More in vitro and in vivo studies comparing different manufacturers and other agents should be performed.

First babies conceived with Automated Intracytoplasmic Sperm Injection.

RESEARCH QUESTION: Can an automated sperm injection robot perform Automated Intracytoplasmic Sperm Injection (ICSIA) for use in human IVF? DESIGN: The ICSIA robot automated the sperm injection procedure, including injection pipette advancement, zona pellucida and oolemma penetration with piezo pulses, and pipette removal after sperm release. The robot was first tested in mouse, hamster and rabbit oocytes, and subsequently using discarded human oocytes injected with microbeads. A small clinical pilot trial was conducted with donor oocytes to study the feasibility of the robot in a clinical setting. The ICSIA robot was controlled by engineers with no micromanipulation experience. Results were compared with those obtained with manual ICSI conducted by experienced embryologists. RESULTS: The ICSIA robot demonstrated similar results to the manual procedure in the different animal models tested as well as in the pre-clinical validations conducted in discarded human oocytes. In the clinical validation, 13 out of 14 oocytes injected with ICSIA fertilized correctly versus 16 out of 18 in the manual control; eight developed into good-quality blastocysts versus 12 in the manual control; and four were diagnosed as chromosomally normal versus 10 euploid in the manual control. Three euploid blastocysts from the ICSIA robot group have been transferred into two recipients, which resulted in two singleton pregnancies and two babies born. CONCLUSIONS: The ICSIA robot showed high proficiency in injecting animal and human oocytes when operated by inexperienced personnel. The preliminary results obtained in this first clinical pilot trial are within key performance indicators.