[Immunopathology and immunomodulatory roles of interleukin-12 in periodontal disease].

PURPOSE: To investigate the immunopathology and immunomodulatory roles of interleukin-12 (IL-12) in periodontal disease. METHODS: Ninety-eight patients with chronic periodontitis from January 2016 to January 2019 were enrolled and divided into mild group (30 cases), moderate group (35 cases) and severe group (33 cases) according to the severity of periodontitis; meanwhile, 30 healthy subjects who underwent periodontal examination in our hospital were selected as the control group. Clinical periodontal indicators including probing depth(PD), attachment loss(AL), plaque index(PLI), bleeding index(BI), Th cell expression (Th1, Th2, Th17) in peripheral blood, IL-12 levels in gingival crevicular fluid (GCF) and serum were measured. SPSS 20.0 software package was performed to analyze the correlation between IL-12 levels in GCF and serum and Th1, Th2, Th17, PD, AL, PLI, and BI. RESULTS: The differences of PD, PLI and BI among the groups were statistically significant(P<0.05). The levels of PD, PLI and BI in the mild, moderate and severe group were significantly higher than those in the control group (P<0.05). The difference of AL index among mild, moderate and severe group was statistically significant(P<0.05). The PD, AL, PLI, and BI in the moderate and severe group was significantly higher than those in the mild group(P<0.05), and the severe group was significantly higher than the mild group(P<0.05). Th1, Th2 and Th17 were significantly higher in the mild, moderate and severe group than in the control group(P<0.05); the moderate, severe group was significantly higher than the mild group in terms of Th1, Th2 and Th17 (P<0.05), and the severe group was significantly higher than the moderate group (P<0.05). The IL-12 levels in GCF and serum of the mild, moderate, and severe groups were significantly higher than those of the control group (P<0.05); IL-12 levels in the the moderate and severe groups were significantly higher than those in the mild group (P<0.05), and the IL-12 were significantly higher in the severe group than in the moderate group (P<0.05); IL-12 was positively correlated with PD, AL, PLI, BI, Th1, Th2 and Th17(P<0.05). H-E staining showed there were fewer lymphocytes in the mild group, more lymphocytes in the moderate group, and dense lymphocytes in the severe group with significant hemorrhage in intercellular mesenchyme. The IL-12 protein positive staining results were expressed in gingival tissue lymphocyte pulp with significant brown observed. The positive staining of IL-12 protein in the gingival tissues in the mild, moderate and severe group was significantly higher than in the control group, and the staining was aggravated with mild, moderate and severe inflammatory changes. CONCLUSIONS: IL-12 is involved in the immunoregulatory mechanism of periodontal disease and may be a key pro-inflammatory cytokine in the development of periodontitis.

Genotypic distribution of Candida albicans in dental biofilm of Chinese children associated with severe early childhood caries.

AIM: Candida albicans causes a wide range of infections in the oral mucosa, especially candidiasis. A strong association has been found between C. albicans and dental caries. In this study, we investigated the presence and genotypic distribution of C. albicans in the dental biofilm of Chinese children with severe early childhood caries (S-ECC). DESIGN: Dental biofilm samples were collected from 41 Chinese children (21 children with S-ECC and 20 children without caries) aged 3-6 years. Samples collected were cultured in CHROMagar Candida (CA) medium. Cellular DNA of typical C. albicans isolates in the CA medium was isolated, and PCR using primers reported to span a transposable intron region in the 25S rRNA gene was performed to determine genotypic subgroups. RESULTS: C. albicans was detected in 57.1% of individuals with S-ECC. Additionally, three genotypic subgroups of C. albicans (genotypes A, B, and C) were found in children with S-ECC, and genotype A was dominant. CONCLUSIONS: C. albicans is an important component of dental biofilm associated with S-ECC, and C. albicans genotypic subgroup A is the dominant strain in the dental biofilm of children with S-ECC.

[Evaluation of chemomechanical and traditional mechanical caries removal in indirect pulp capping of symmetric primary molars].

OBJECTIVE: To evaluate the difference between chemomechanical and traditional mechanical caries removal in indirect pulp capping of the symmetric primary molars. METHODS: A total of 192 children with deep caries in the two symmetric primary molars were studied. The two symmetric primary molars were divided into two groups for treatment with chemomechanical method with Carisolv(TM) system or traditional mechanical method. After caries removal, calcium hydroxide agent was placed as the protective base, and glass ionomer cement was used to restore the teeth. The patients were followed up every 1 month within one year after the operation. RESULTS: The percentage of healthy primary molar pulp was 95.3% with chemomechanical method and 87.0% with traditional method, showing a significant difference between the two methods. CONCLUSION: Chemomechanical caries removal is more effective in preserving the healthy pulp than the traditional method.

[Distribution of Bifidobacterium in oral cavities of children and the relations with caries].

OBJECTIVE: To explore a selected-media of Bifidobacterium from oral cavity, to detect the distribution of Bifidobacterium in different sites of children and primarily investigate the relationship between oral Bifidobacterium and early childhood caries. METHODS: 70 children aged from 3 to 5-year-old were selected, 30 children were caries-free and 40 were severe early childhood caries (S-ECC). Saliva was collected and plaque samples from the 30 healthy subjects were pooled. For S-ECC group, plaques were collected separately from four different sites as follows: Saliva, surfaces of intact enamel, surfaces of white spot-lesions, and deep dentin-lesions. Samples would be grown in the selected-media, and the whole DNA of bacteria was extracted. Polymerase chain reaction was performed with specific primers and the results were analyzed by the electrophoresis. RESULTS: Bifidobacterium were detected 0 in the caries-free children, while 47.5% in the S-ECC group. There was significant difference between two groups (P < 0.05) and there was no difference between different sites of teeth in S-ECC group (P > 0.05). 27.5% Bifidobacterium were detected in saliva, 27.5% on surfaces of intact enamel, 20.0% on surfaces of white spot-lesions and 22.5% in deep dentin-lesions. 10% Bifidobacterium dentium were detected in saliva, 7.5% on surfaces of intact enamel, 7.5% on surfaces of white spot-lesions and 10.0% in deep dentin-lesions. CONCLUSION: One type of modified selected media of Bifidobacterium in oral cavity was explored. Bifidobacterium may be related to the occurrence of the S-ECC and has nothing to do with different sites of teeth in children.