Reversal of primary root caries lesions after daily intake of milk supplemented with fluoride and probiotic lactobacilli in older adults

Interventional study in older adults recruited from a specialist dental clinic in Ljungby, Sweden. Eligible participants were generally healthy adults aged 58-84 years with at least two primary root caries lesions, no acute or immune-compromising condition, no subjectively reported xerostomia, and tolerance of dairy products; dementia or Alzheimer’s disease were exclusion criteria. The active intervention arms were compared against a standard milk control in a four-group design.

Three oral milk regimens were tested for 15 months in older adults: milk containing fluoride 5.0 mg F/L, milk containing Lactobacillus rhamnosus LB21 at 10^7 CFU/mL, or milk containing both agents. Participants consumed 200 mL daily after adding 1.0 mL of capsule solution; the comparator was standard milk.

Daily milk supplementation with fluoride and/or probiotic Lactobacillus rhamnosus LB21 appeared to reverse or remineralize primary root caries lesions, with the clearest benefit when fluoride was included. In the fluoride plus probiotic group, the lesion distribution shifted from 0/72/28 at baseline to 59/38/3 for grade 1/2/3 lesions at 15 months, and ECM increased from 256 (138) to 1127 (683), p<0.05. Fluoride alone also improved ECM from 317 (221) to 883 (453), while probiotic alone improved more modestly from 306 (226) to 581 (292). No severe adverse effects were reported in any active arm.

Completed sample sizes were smaller than planned in the active arms (26, 27, and 22 completers versus 40 planned per group), which limits precision. The study was conducted in a single specialist dental clinic population, so generalizability is limited. Some reported microbiologic outcomes were variable, and the provided data do not include detailed control-arm results or full randomization details.