Objective To evaluate the efficacy of light cured composite resin and glass ionomer cement for wedge shaped defect filling. Methods PubMed, The Cochrane Library (Issue 3, 2016), EMbase, CNKI, CBM, VIP and WanFang Data were searched from inception to April 5th 2016, to collect randomized controlled trials (RCTs) of light cured composite resin versus glass ionomer cement for wedge shaped defect filling. According to the inclusion and exclusion criteria, two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies. Then, meta-analysis was performed by RevMan 5.2 software. Results A total of 12 studies, involving 3 744 cases of teeth were included. Meta-analysis results showed that there was no significant difference in the two groups on the shedding rate after 2 years (OR=1.19, 95%CI 0.70 to 2.02,P=0.53). But the wear rate of the light cured composite resin group was significantly lower than that of the glass ionomer cement group (Peto OR=0.31, 95%CI 0.22 to 0.44,P<0.000 01). The light cured composite resin group had higher rate of micro leakage or secondary caries rate (OR=1.83, 95%CI 1.11 to 3.01,P=0.02) and incidence of endodontic or periapical lesions (Peto OR=2.84, 95%CI 1.82 to 4.45,P<0.000 01) than the glass ionomer cement group. Conclusion Glass ionomer cement for filling wedge-shaped defects of 2 years after the wear degree is higher than the light cured composite resin, but the occurrence probability of micro leakage or secondary caries and stimulation to pulp are lower than the light cured composite resin. Because of the limitations of the quality of the included studies, the above conclusion still needs to be verified by more high-quality studies.
ObjectiveTo investigate whether there is a causal relationship between reproductive history (number of children, age at first birth) and the risk of hormone-related cancers (breast, endometrial, and ovarian) in women. MethodsUnivariate and multivariate Mendelian randomization (MR) methods were used to investigate the causal effects of the number of children (childlessness in infertile women and number of children ever born in fertile women) and age at first birth on three hormone-related cancers. The inverse variance weighting method was used for the primary analysis, and sensitivity analyses and reliability tests were used to ensure the reliability of the results. ResultsUnivariate MR showed that infertile women had a higher risk of breast cancer compared with fertile women (OR=1.07, 95%CI 1.05 to 1.09, P<0.001). Multivariate MR showed that among fertile women, after accounting for the effect of age at first birth, higher number of children ever born may be associated with lower risk of breast cancer (OR=0.61, 95%CI 0.43 to 0.85, P<0.01). Neither univariate nor multivariate MR found a causal relationship between age at first birth and hormone-related cancers, and no causal relationship was found between the number of children ever born and endometrial and ovarian cancers; sensitivity analyses and reliability tests demonstrated that the results were unlikely to be affected by heterogeneity and horizontal pleiotropy. ConclusionThe more children a normal woman has, the lower her risk of breast cancer. Infertile women face a higher risk of breast cancer.