Clinical effects of different etching modes for universal adhesives: a systematic review and meta-analysis.

BACKGROUND: To evaluate the clinical performance of universal adhesives in etch-and-rinse or self-etch application modes through meta-analysis. METHODS: A literature search was performed by two reviewers in the PubMed, Cochrane Library, and Embase databases (from January 2000 to March 2020). A total of 2,516 non-replicated records were identified and filtered. Studies that evaluated the clinical performance of universal adhesives using etch-and-rinse or self-etch mode were included. RevMan 5.3.5 (Cochrane, London, UK) was used to perform the meta-analysis. RESULTS: A total of 13 studies were included in the meta-analysis. The retention rates were higher in etch-and-rinse groups compared with self-etch groups [odds ratio (OR) =0.35, 95% confidence interval (CI): 0.18-0.71, P=0.003]. The etch-and-rinse approach also had better performance in marginal adaptation (OR =0.49, 95% CI: 0.36-0.67, P<0.001) and marginal staining (OR =0.49, 95% CI: 0.36-0.66, P<0.001). The current data showed a very low incidence rate of secondary caries or postoperative sensitivity, and there were no significant differences in the incidence rates between the etch-and-rinse groups and self-etch groups. DISCUSSION: The current evidence shows that, compared with self-etch approach, the etch-and-rinse approach for universal adhesives provides improved clinical outcomes in terms of retention rates, marginal adaptation, and marginal staining.

Temperature-dependent circular conversion dichroism from chiral metasurfaces patterned in Dirac semimetal Cd3As2.

Chiral metasurfaces patterned with L-shaped holes in a thin film of Dirac semimetal Cd3As2 are designed. The impact of temperature T on circular conversion dichroism, mainly characterized by circular polarization differential transmittance (CPDT), is studied by rigorous coupled-wave analysis. The results show that decreasing T will give rise to the appearance of much more narrow CPDT peaks and dips, and the maximum differential transmittance between two opposite circularly polarized light can reach above 0.60 by optimizing the structural parameters at 80 K. As the T increases, the differential transmittance gradually decreases, and the CPDT peak and dip values exhibit variation tendencies of 'Z' and 'S' types, respectively. Two simple formulae of CPDT extreme values with respect to T are derived, predicting that the decreasing tendency will reach saturation when T ≥ 500 K. Differing from the wavelength-independent variation trend of differential transmittance, CPDT extremum positions mainly show a blueshift (redshift) tendency at the wavelength λ > 10 µm (λ < 5 µm) as the T increases. Moreover, evolutions of CPDT with various factors including the thickness of Cd3As2, incident and azimuth angles are also clearly unveiled.

Dental caries and associated factors among Chinese children and adolescents: A protocol for systematic review and meta-analysis.

BACKGROUND: Dental caries is a common disease under the action of many factors. Dental caries may occur in all age groups, among which children and adolescents are at high risk of dental caries. Early identification of the risk factors of dental caries is very important for clinical staff to prevent and intervene as soon as possible and reduce the incidence of dental caries. Although Chinese scholars have studied and summarized the risk factors of dental caries in children and adolescents, the conclusions are different. Therefore, in this study, meta-analysis was used to summarize the risk factors of dental caries in Chinese children and adolescents, and to explore the characteristics of high-risk groups of dental caries, so as to provide reference for early detection and prevention of dental caries. METHODS: Medical specialty databases like PubMed, Embase, Cochrane Library, Web of Science, China Biology Medicine Database, China National Knowledge Infrastructure, China Science and Technology Journal Database, and Wanfang Database were consistently and exhaustively searched. According to the method of evidence-based medicine, the inclusion and exclusion criteria were established, and the meta-analysis of all eligible research results was carried out by using Review Manager 5.3 software. RESULTS: We will disseminate the findings of this systematic review and meta-analysis via publications in peer-reviewed journals. CONCLUSIONS: Our study was carried out to estimate the pooled prevalence of dental caries and its associated factors among Chinese children and adolescents. OSF REGISTRATION NUMBER: DOI 10.17605/OSF.IO/RA9D6.

[Surgical treatment of nasosinus tumor involving base of the anterior cranial fossa].

OBJECTIVE: To explore the operative approach for nasosinus tumors involving the base of the anterior cranial fossa. METHOD: Seven cases with defects, diameter less than 2 cm, on the skull base without damage of the duramater were not repaired. Other 7 cases with defects, diameter more than 2.5 cm, on both the skull base and duramater were covered with frontalis muscle flap or temporalis fascia flap. RESULT: Following up 1-8 year. 6 of the 11 malignant tumors survived after 3 years and 2 cases did after 4 years; 3 cases of benignant tumors are still alive, neither meningoephalocele nor cerebrospinal fluid fistula and extracranial or intracranial infection occurred. CONCLUSION: This operative mode is closer to the tumor and easy to repair duramater and stop bleeding, and has fine exposure of every nasal sinus, minimal retraction of the frontal lobe. If diameter of defect is more than 2 cm on the skull base, the reconstruction is necessary.