Several studies have investigated the effect of bleaching on dental tissues. The evaluation of the effect of home bleaching with 10% carbamide peroxide is important for assessing alterations in enamel microhardness that may affect dental health in terms of resistance to masticatory forces. This meta-analysis was performed in order to determine scientific evidence regarding the effects of home vital bleaching with 10% carbamide peroxide gel on the microhardness of human dental enamel. A systematic electronic literature search was conducted in the PubMed and Web of Science databases using search terms. Two independent researchers evaluated the information and methodological quality of the studies. Inclusion and exclusion criteria were established for article selection; further, only studies published in English were selected. Thirteen studies that met all of the inclusion and exclusion criteria were selected and underwent statistical analysis. The results of this meta-analysis showed no significant changes in enamel microhardness when using the 10% carbamide peroxide bleaching gel over periods of 7, 14 and 21 days.

The semen of rams suffers during cryopreservation, and the sperm plasma membrane breaks down during the process, creating the deleterious effect of reducing their fertilization capacity. The homeopathic medicines Medicago sativa and Aloe vera were tested to evaluate membrane protection during cryopreservation in diluent media established for the species. Semen samples from five rams were frozen in two different diluents and analyzed after thirty days of freezing. The Glycine-Yolk-Milk diluent supplemented with Medicago sativa in the twelfth Hahnemann's centesimal potency led to decreased loss of motility and vigor of semen in rams evaluated in farms.sperm membrane lead to decreased respiratory activity, large-scale cryo-capacitation, modification of the interaction with cells of the oviduct, and a small increase in rates of embryonic mortality, further decreasing the fertilization rate [13] .The medications Medicago sativa and Aloe vera promote the reduction of tiredness, fatigue and malnutrition, and weight and movement loss, arising from nervousness, insomnia, and indigestion and improvement with cold, respectively, enabling the improvement of these symptoms in humans [14].Several studies have been conducted to improve the freezing techniques for semen, aiming to preserve the integrity of sperm cells during the process [15]. As the nature of diluents is important for preserving the biological properties of the sperm during freezing [16], this study aimed to evaluate the potency effect of two medications described in homeopathic medicine for maintaining sperm integrity after cryopreservation, namely, the addition of Medicago sativa and Aloe vera to the diluents TRIS-S (standard) and Glycine-Yolk-Milk (GGL) and evaluation of the parameters motility and vigor post-thaw.