Objective To evaluate the effect of pretreatment with ethanol on dentin to compensate premature volatilization of self-etch adhesive system.Methods Thirty-two intact human molars were randomly divided into two groups using a table of random numbers (n =16):A,an acetone-base adhesive (G-bond) and B,an ethanol-based adhesive(Clearfile S3 bond).Then each group was randomly assigned into foursub groups (n =4):group 1,no premature volatilization ; group 2,premature volatilization ; group 3,premature volatilization + stepwise ethanol pretreatments; and group 4,premature volatilization ± absolute ethanol treatment.After composite resin building,microtensile bond strengths(MTBS) of each subgroup were then tested.Fracture modes were classified by stereomicroscopy and representative interface was observed by field-emission scanning electron microscopy (FE-SEM).Results For adhesive A,there was significant difference on MTBS among different subgroups(P ＜0.05) ; the MTBS of group A2[(26 ± 12) MPa] and A4[(27 ±7) MPa] was lower than that of group A1 [(41 ± 11) MPa] and A3[(40 ± 11) MPa] (P ＜ 0.05).No significant different was found between group A2 and A4 (P ＞ 0.05) ; neither between group A1 and A3 (P ＞ 0.05).For adhesive B,there was no difference on MTBS among different subgroups (P ＞ 0.05).FE-SEM showed that the main fracture mode was located at the bottom of the hybrid layer for adhesive A groups,the collagen fibrils were capsulated by resin monomers more densely in group A1 and group A3 in comparison with other two subgroups.For adhesive B groups,the main failure modes were at the top of the hybrid layer.Conclusions Premature volatilization can obviously decrease the bonding strength of acetone-base self-etch adhesives,but has no significant effect on ethanol-based self-etch adhesives.Dentin pretreatment with a series of increasing ethanol concentrations can effectively compensate the adverse effect of premature volatilization of acetone-base self-etch adhesives on bonding strength.

Objective To compare the effects of exogenous enzymes on the degradation of adhesive-dentin interface.Methods Forty molars were sectioned to expose the middle-coronal dentin surface and randomly divided into two adhesive systems:an etch-and-rinse adhesive Adper Single Bond 2 and a self-etching adhesive G-Bond.After composite building up,the specimens were then randomly assigned to four groups(n=5 for each group) as follows:group 1,24 h of water storage(the control group);group 2,six months of water storage;group 3,twelve weeks storage in artificial saliva containing clostridium histolyticum collagenase;group 4,twelve weeks storage in artificial saliva containing cholesterolesterase.The microtensile bond strengths(MTBS) were then tested.The failure modes and nanoleakage were analyzed.Results After aging treatments,the three aging groups showed significantly lower MTBS compared with the control group in both adhesive systems(P＜0.05).For etch-and-rinse adhesive Adper Single Bond 2,the MTBS of group 3([19.6±3.5] MPa) was lower than that of group 2([23.4±4.2] MPa) and group 4([24.2±4.2] MPa) (P＜0.05).For self-etching adhesive G-Bond,there was no difference on MTBS among different aging groups (P＞0.05).SEM observation showed that,compared with the control group,water storage(group 2) and the exogenous enzymes(group 3 and 4) increased the nanoleakage expression(silver deposition) of both adhesive systems.Adhesive failure was the predominant fracture modes in all groups.Conclusions Storage in artificial saliva containing clostridium histolyticum collagenase or cholesterol esterase could be used to accelerate the degradation process of adhesive-dentine interface.

In the past ten years, the research and application of microbiome has continued to increase. The microbiome has gradually become the research focus in the fields of life science, environmental science, and medicine. Meanwhile, many countries and organizations around the world are launching their own microbiome projects and conducting a multi-faceted layout, striving to gain a strategic position in this promising field. In addition, whether it is scientific research or industrial applications, there has been a climax of research and a wave of investment and financing, accordingly, products and services related to the microbiome are constantly emerging. However, due to the rapid development of microbiome sequencing and analysis related technologies and methods, the research and application from various countries have not yet unified on the standards of technology, programs, and data. Domestic industry participants also have insufficient understanding of the microbiome. New methods, technologies, and theories have not yet been fully accepted and used. In addition, some of the existing standards and guidelines are too general with poor practicality. This not only causes obstacles in the integration of scientific research data and waste of resources, but also gives related companies unfair competition opportunity. More importantly, China still lacks national standards related to the microbiome, and the national microbiome project is still in the process of preparation. In this context, the experts and practitioners of the microbiome worked together and developed the consensus of experts. It can not only guide domestic scientific research and industrial institutions to regulate the production, learning and research of the microbiome, the application can also provide reference technical basis for the relevant national functional departments, protect the scale and standardized corporate company's interests, strengthen industry self-discipline, avoid unregulated enterprises from disrupting the market, and ultimately promote the benign development of microbiome-related industries.
China ; Consensus ; Humans ; Industry ; Microbiota