Photo credit: By @alex_tsarik at Twenty20. Teeth Whitening People are generally vain in nature and so they continuously look for ways to improve their appearances as they grow old. While other people go for physical improvements like liposuction, nose lift, and facelift, there are people who are more concerned with keeping their pearly whites whiter than ever. As people grow older their teeth grow darker due to their lifestyle and personal circumstances. A person’s teeth become darker through continuous exposure…