An application on meta-analysis methodology and clinical performance of universal adhesives

This study aims to provide information about the concept of meta-analysis, its stages, the models used in the analysis and meta-analysis methods, and to make an application on the clinical performance of universal adhesives. Meta-analysis is a statistical method that combines the results of research conducted at different places and times on the same subject and provides a general conclusion on that subject. To eliminate the lack of information and conflicting results arising from insufficient data, previous studies in this field can be combined and a final and valid result can be produced by the meta-analysis method. Universal adhesives used in dentistry can be applied in two different ways: etch&rinse and self-etch. However, it is not clear in which application technique universal adhesives are more successful. In order to explain the meta-analysis method, 15 studies evaluating the clinical performance of universal adhesives used in dentistry with modified USPHS criteria were selected as materials according to the inclusion and exclusion criteria. Egger regression method was used to test whether there was publication bias among the studies included in the meta-analysis, and it was also examined by drawing a funnel plot. Whether there was heterogeneity between studies was examined using Cohran's Q test and I2 statistics. Since there was no heterogeneity between studies, the fixed effect model method was used in general effect size calculations. It was determined that there was no bias between the studies included in the meta-analysis (p>0.05). It was determined that there was no heterogeneity between the studies (p<0.05). As a result of the meta-analysis of studies within the 95% confidence interval obtained, the average effect size was 0.136 for marginal coloration (p = 0.790); 0.027 for marginal adaptation (p=0.958); 0.927 for retention (p=0.009); 0.091 for fracture (p=0.856); 0.204 for sensitivity (p=0.689); for caries, it was found to be 0.127 (p=0.803). It can be said that there is no difference between the use of universal adhesives in the "etch-and-rinse and self-etch" application mode according to the criteria of marginal discoloration, marginal adaptation, fracture, sensitivity and caries, but there is a difference according to the retention criterion.