Effectiveness of the use of xylitol chewing gum in prevention of dental caries: A systematic review.

This systematic review of the literature assessed the effectiveness of using chewing gum containing only xylitol compared to prevention strategies or placebo in reducing the incidence of carious lesions in children using data obtained from randomized controlled trials. Electronic search was carried out in PubMed MEDLINE, Latin American and Caribbean Literature on the Health Science, Web of Science, Scopus, Science Direct, and Scientific Electronic Library Online through the period between 2000 and 2020. Included clinical studies were done in children when the xylitol was dispensed in gum and the preventive effect of xylitol on tooth decay was compared to other preventive strategies or control groups. The studies were evaluated for their quality to obtain the level of evidence. The preventive fraction of each study was extracted. Two hundred studies were found. After analyzing the inclusion and removal of duplicates, only five studies were analyzed for the quality of evidence. With the analysis through the Grading of Recommendations Assessment, Development, and Evaluation system, it was possible to verify the very low level of scientific evidence on the effectiveness of gums containing only xylitol for the prevention of caries in children. The preventive fraction obtained varied between - 0.31 and 0.57 depending on the compared prevention strategy. The conflicting results, limitations, and inconsistencies of the studies allow us to establish that there is insufficient evidence to support the use of gums containing only xylitol for the prevention of caries in children. Other properly designed clinical trials need to be carried out.

Effects of caffeine supplementation on muscle endurance, maximum strength, and perceived exertion in adults submitted to strength training: a systematic review and meta-analyses.

This study aimed to determine the effects of caffeine supplementation on muscle endurance, maximum strength, and ratings of perceived exertion (RPE) in individuals undergoing strength training with external resistance exercises. A search of three databases (PubMed, LiLACS, and CENTRAL) and gray literature was carried out to find randomized controlled trials, with a double-blind design, which investigated the effects of caffeine supplementation in healthy adults. Meta-analyses of weighted mean differences (WMD) and standardized mean differences (SMD) between caffeine and placebo groups from individual studies were performed using a random-effects model. Nineteen studies were included in the quantitative synthesis. Only the bench press and the leg press exercises were assessed in a sufficient number of studies to be included in meta-analyses. In the bench press exercise, caffeine supplementation improved strength resistance (WMD 0.87 (95% confidence interval (CI): 0.33, 1.41) repetitions, P = 0.001; 15 studies), and maximum strength (WMD 2.01 (95% CI: 0.20, 3.80) kg, P = 0.02; 7 studies), but showed no effect in RPE (SMD -0.45 (95% CI: -1.40, 0.48), P = 0.34, 7 studies) In the leg press exercise, no significant improvement were observed in muscle endurance (WMD: 1.24 (95% CI: -0.21, 2.70) repetitions, P = 0.09, 8 studies), maximum strength (WMD 8.49 (95% CI: -11.91, 28.90) kg, P = 0.415, 3 studies), and in RPE (SMD -0.17 (95% CI: -1.62, 1.27), P = 0.812, 3 studies). Caffeine supplementation showed a significant ergogenic effect on muscle endurance and maximum strength in the bench press exercise. More investigations are needed to clarify the contradictions in its effects regarding lower-body exercises.