Solid-head power toothbrushes retain less bacteria compared to hollow-head toothbrushes, according to researchers at The University of Texas Health Science Center at Houston (UTHealth) School of Dentistry, who found up to 3,000 times the bacterial growth on hollow-head toothbrushes The results of the study are published in the August issue of the Journal of Dental Hygiene. Lead author and professor at the UTHealth School of Dentistry, Donna Warren Morris, R.D.H., M.Ed., notes that microbial counts were lower in the solid-head toothbrush group than in the two hollow-head toothbrush groups in 9 out of 10 comparisons. The study was conducted over a three-week period where participants brushed twice daily with one out of three randomly assigned power toothbrushes. Participants used non-antimicrobial toothpaste and continued their flossing routine throughout the study, but refrained from using other dental products like mouthwash.