# Propolis as Natural Product in the Oral Cavity Bacterial Infections Treatment: A Systematic Review
## 4 Results
### Antibacterial Activity of Propolis in Oral Cavity Bacterial Infections
#### 4.2.2 In Vivo Studies  
The authors of the review study resolved to comment also on _in vivo_ studies, since they believed it was important to highlight the important role of honey in the treatment of oral cavity bacterial infections. [PERSON] et al. [32] evaluated the additional effect of subgingival cleaning with the use of propolisis extract on deep periodontal pockets following a mechanical therapy. In their research, they used both clinical and microbiological parameters. The _in vivo_ study indicated that the total viable counts of anaerobic bacteria decreased, the percentage of sites with low levels increased (< 10 CFU/mL) of _P. gingivalis_, and the number CF sites in group A sites in comparison to group B and C decreased. The study included twenty patients with chronic periodontitis. Irrigation was applied in two groups with the use of: a hydro alcoholic solution of propolisis extract twice a week for two weeks (group A); a placebo twice/week for two weeks (group B). One group was not additionally treated (C). Two weeks after clinical data recording, the researchers collected subgingival plaque samples. Scaling and root planing were also performed. After another two weeks, irrigation began (baseline). Microbiological and clinical data were collected at baseline and after 4, 6, and 24 weeks [32]. [PERSON] et al. [101] analyzed propolisis extract activity against _S. mutans in vivo_. The results showed that the propolisis extract has an _in vivo_ antimicrobial activity against _S.mutans_ and might be used as an alternative solution to prevent dental caries. The results were obtained based on the study of forty-one young volunteers who used a rinse of 3 mL propolisis extract solution for seven days. During the trial, three samples were collected (first: in the morning, the second: 1 hour after the first use of the solution, and the third sample was obtained after 7 days). The alterations in the number of colonies of _S.mutans_ were observed in patients between the 1 st and 2 nd collection, i.e., a decrease in 62% of samples, an increase in 14% of samples, and no change in 24% of samples (an important difference in the number of _S. mutans_ between the collections 1 and 2 defined as mean \(\pm\) SD, 4.275 \(\pm\) 0.8459 versus 2.809 \(\pm\) 2.0911). Whereas, between the 1 st and 3 rd collection, the bacterial concentration detected in patients translated into a reduction in 81% of samples, an increase in 9.5% of samples, and no change in 9.5% samples (between collections 1 and 3: 4.275 \(\pm\) 0.8459 versus 2.4184 \(\pm\) 1.9999). Consequently, a reduced number of _S. mutans_ both after the beginning (collection 2) and after the full treatment (collection 3) was observed [101]. Another group of researchers, [PERSON] et al. [102], assessed the effect of 3% ethanol extract of propolisis (EEP) on the microbiological status of the oral cavity in patients with cleft lip and palate, which were treated with fixed orthodontic appliances. The percentage of the _Actinomyces spp_. and _Capnocytophaga spp_. was statistically significantly decreased compared with baseline in the propolisis group. However, such a result was