Table 6 Presentation of data regarding the effects of probiotics on the amount of bacterial plaque and bacterial colonies accumulated in the gingival sulcus

Bacterial plaque index

Positive effect

Visible reduction that reduces the need for surgical intervention in pockets with a depth of 4–6 mm (Vives-Soler and Chimenos-Küstner 2020)

Probiotics specifically act sensitively to the red periodontal complex (Butera et al. 2022; Invernici et al. 2020)

The reduction of the bacterial load is also expressed in the reduction of mediators in the patient's blood where the probiotic is applied (Bazyar et al. 2020)

Limited effects on the microbial load even in cases where the plaque index is reduced. The sulcus are filled with Bifidobacterium species (Özener et al. 2023)

The plaque index is taken as an accompanying element of other periodontal clinical indices, and not as a measure of the microbial load (Ikram et al. 2019)

Negative effect

The plaque index has the same records as for patients who are treated only with non-surgical periodontal therapy, but the bacterial load of P.gingivalis and T.forsythia is significantly reduced (Patyna et al. 2021)

It has an effect on P. gingivalis and sulcus bacteria but does not significantly reduce the diseased periodontal areas (Pudgar et al. 2021)

Reduces P. gingivalis, but does not act much in peri-implantitis (Ghasemi et al. 2020)

Halitosis of dental origin has no improvement as the microbiological load after 1 month after the application of probiotics (for 8 weeks or for 90 days of application) has no changes (Tay et al. 2022)

TOTAL

4/3

2/1