Clinical and microbiological evaluation of the effect of Lactobacillus reuteri in the treatment of mucositis and peri‐implantitis: A triple‐blind randomized clinical trial

Abstract Background and Objective Oral probiotics appear to improve the treatment of periodontal diseases but there is limited evidence on their efficacy in the treatment of peri‐implant diseases. The objective of the present study was to evaluate, clinically and microbiologically, the effect of the oral probiotic, Lactobacillus reuteri Prodentis, as adjuvant to non‐surgical mechanical therapy in implants with mucositis or peri‐implantitis, placed in patients with a history of periodontal disease. Material and Methods A randomized, controlled, parallel‐design, triple‐blind prospective clinical study was designed. Patients included in the study were partially edentulous and had implants with mucositis or peri‐implantitis. Implants with radiographic bone loss of ≥5 mm and/or ≥50% of the implant length were excluded, and only one implant per patient was included. After non‐surgical mechanical therapy, subjects were randomly assigned to take either 1 probiotic lozenge or 1 placebo lozenge every day for 30 days. Clinical measurements were taken in the whole mouth (general plaque index and general bleeding on probing) and at the implant site (probing pocket depth, plaque index and bleeding on probing) at baseline and 30 and 90 days Microbiological examination (to identify Aggregatibacter actinomycetemcomitans , Tannerella forsythia , Porphyromonas gingivalis , Treponema denticola , Prevotella intermedia , Peptostreptococcus micros , Fusobacterium nucleatum , Campylobacter rectus and Eikenella corrodens ) was performed at the same study time points that clinical measurements were made. Results A total of 44 patients – 22 with mucositis and 22 with peri‐implantitis – randomly received treatment with either probiotic or placebo. The probiotic L. reuteri , together with mechanical therapy, produced an additional improvement over treatment with mechanical therapy alone, both in the general clinical parameters of patients with mucositis (bleeding on probing) and at the level of implants with mucositis (probing pocket depth) or peri‐implantitis (bleeding on probing and probing pocket depth). However, L. reuteri had a very limited effect on the peri‐implant microbiota because the only parameter in which a significant decrease was found was the bacterial load of P. gingivalis in implants with mucositis (P = .031). Conclusion The administration of a daily lozenge of L . reuteri for 30 days, together with mechanical debridement of the whole mouth, improved the clinical parameters of implants with mucositis or peri‐implantitis over a period of at least 90 days, but the microbiological effect was much more limited. Probiotics provide an alternative therapeutic approach to consider in the prevention and treatment of peri‐implant diseases, but further long‐term prospective studies with standardized variables are needed.