Some other popular additives in toothpaste may be less controversial. Toothpastes containing baking soda (small crystals of sodium bicarbonate) have been found to remove plaque better than those without, according to the authors of one meta-analysis, though they noted more follow-up studies were needed (the authors of that study stated that they had received funds from toothbrush and toothpaste manufacturers in the past). The same analysis found that baking-soda toothpastes may give a slight reduction in bleeding due to gingivitis.