Effect of Lactobacillus rhamnosus and Bifidobacterium lactis on gingival health, dental plaque, and periodontopathogens in adolescents: a randomised placebo-controlled clinical trial - Alanzi, A; Honkala, S; Honkala, E; Varghese, A; Tolvanen, M; Söderling, E (Benef Microbes, 2018)