Children, adolescents and periodontal diseases

Necrotizing Gingivitis: Microbial Diversity and Quantification of Protein Secretion in Necrotizing Gingivitis

Necrotizing gingivitis (NG) is a necrotizing periodontal disease that differs from chronic gingivitis (CG). To date, both the microbiological causes and the involved host cytokine response of NG still remain unclear. Here, we investigated corresponding interdental plaque and serum samples from two groups of Chinese patients with CG (n = 21) or NG (n = 21). The microbiota were studied by 16S rRNA Illumina MiSeq sequencing of the microbial metagenome and by assessing quantitatively the abundance of the phylum Bacteroidetes, the genus Prevotella and the species T. forsythia, P. endodontalis, and P. gingivalis using fluorescence in situ hybridization (FISH). With respect to the associated host response, the levels of 30 inflammatory mediators were quantified by multiplex immunoassay analysis. Differential microbial abundance analysis of the two disease groups revealed at the phylum level that Proteobacteria accounted for 67% of the differentially abundant organisms, followed by organisms of Firmicutes (21%) and Actinobacteria (9%). At the species level, significant differences in abundance were seen for 75 species of which 58 species were significantly more abundant in CG patients. Notably, the FISH analysis revealed that Bacteroidetes was the most prevalent phylum in NG. The multiplex cytokine assay showed significant quantitative differences between the disease groups for eight analytes (GM–CSF, G–CSF, IFN–α, IL–4, IL–13, TNF–α, MIG, and HGF). The G–CSF was found to be the most significantly increased inflammatory protein marker in NG. The next-generation sequencing (NGS) data supported the understanding of NG as a multi-microbial infection with distinct differences to CG in regard to the microbial composition.

Immune system transcriptome in gingival tissues of young nonhuman primates

BACKGROUND AND OBJECTIVE

Young/adolescent humans harbor many microorganisms associated with periodontal disease in adults and show substantial gingival inflammatory responses. However, younger individuals do not demonstrate the soft- and hard-tissue destruction that hallmark periodontitis.

MATERIAL AND METHODS

This study evaluated responses to the oral microbial ecology in gingival tissues from clinically healthy young Macaca mulatta (< 3 years of age) compared with older animals (5-23 years of age). RNA was isolated from the tissues and analyzed for the transcriptome using the Rhesus Macaque GeneChip (Affymetrix).

RESULTS

Global transcriptional profiling of four age groups revealed a subset of 159 genes that were differentially expressed across at least one of the age comparisons. Correlation metrics generated a relevance network abstraction of these genes. Partitioning of the relevance network revealed seven distinct communities comprising functionally related genes associated with host inflammatory and immune responses. A group of genes was identified that were selectively increased/decreased or positively/negatively correlated with gingival profiles in the animals. A principal components analysis created metagenes of expression profiles for classifying the 23 animals.

CONCLUSION

The results provide novel system-level insights into gene-expression differences in gingival tissues from healthy young animals, weighted toward host responses associated with anti-inflammatory biomolecules or those linked with T-cell regulation of responses. The combination of the regulated microenvironment may help to explain the apparent 'resistance' of younger individuals to developing periodontal disease.

Evaluation of cross-linked chitosan microparticles containing metronidazole for periodontitis treatment

The aims of this study were to find the optimal formulation for the preparation of metronidazole-loaded chitosan microparticles (MTZ-MPs) via an emulsion cross-linking process, and to compare the in vitro release of MTZ from hydrogels and films containing the drug in forms of MTZ-MPs and raw powders. The effects of emulsifier type and concentration, amount of cross-linking agent, cross-linking time, drug:chitosan ratio, form of drug adding and washing method on the properties of the MTZ-MPs were investigated. The results indicated that the optimal conditions for round and free-flowing MTZ-MPs with a high percentage of entrapped drug and preferable release profile were 1% of Span80 in soybean oil, 5% of glutaraldehyde based on chitosan solution, 30 min of cross-linking time, 1:1 drug:chitosan ratio, drug adding in form of ethanol solution and washing with hexane only. MTZ-MPs prepared from the optimal formulation were incorporated in mucoadhesive hydrogel and film. The release profiles of the drug from hydrogel and film containing MTZ-MPs were in prolong pattern compared with those containing drug powders. However, the hydrogels exhibited higher preferable pattern of release profile than the films. Therefore, the hydrogel containing MTZ-MPs was possible to be further clinically investigated for peridontitis treatment.

Autoimmune responses in periodontal diseases

Periodontal diseases are characterized by localized infections and inflammatory conditions and directly affect teeth supporting structures which are the major cause of tooth loss. Several studies have demonstrated the involvement of autoimmune responses in periodontal disease. Evidences of involvement of immunopathology have been reported in periodontal disease. Bacteria in the dental plaque induce antibody formation. Lymphocytes, cytokines and complement system are reported to have an important role in the progression of periodontal disease. The present review describes the involvement of autoimmune responses in periodontal diseases. The mechanisms underlying these responses are also discussed.

Low-level laser efficiency in the therapy of chronic gingivitis in children

Background/Aim. Gingivitis is a frequent phenomenon in children considered to be a risk factor for the occurrence and progression of paradontal tissue disease. So, it is necessary not only to identify inflammation, but also to react in due time and adequately in order to avoid further disease spread and the beginning of periodontitis. The aim of this study was to determine the efficiency of a low-level laser application in the therapy of chronic gingivitis in children. Methods. The study a included hundred of children with permanent dentition suffering from chronic gingivitis. All the examinees were divided into two groups: group I - 50 examinees with chronic gingivitis, who underwent the basic therapy; group II - 50 examinees with chronic gingivitis, who underwent the basic therapy and also a therapy with a low-level laser. Evaluation of the condition of oral hygiene, the health of gingiva and periodontium were done using appropriate index before and after the therapy. Results. For the plaque index (PI) following results were obtained: in the group I PI = 1.94, and in the group II PI = 1.82. After the therapy in both groups PI was 0. In the group I sulcus plaque index (SPI) was 2.02 before the therapy and 0.32 after the therapy. In the group II SPI was 1.90 before the therapy, and 0.08 after the therapy. In the group I Community Periodontal Index of Treatment Needs (CPITN) was 1.66 before the therapy, and 0.32 after the therapy, and in the group II CPITN was 1.60 before the therapy, and 0.08 after the therapy. Conclusion. Chronic gingivitis in children can be successfully cured by the basic treatment. The use of a low-level laser can significantly improve this effect.

Periodontal and soft tissue prevention strategies for the adolescent dental patient

Recent research has refocused attention on the contribution of periodontal health to the general health of patients at various ages. This article describes changes in the periodontal tissues of adolescent dental patients related to hormonal fluctuations, lack of proper oral hygiene, and risk-taking behaviors. Attention is placed on the development and prevention of acute and chronic gingival conditions in addition to gingival tissue enlargement as one side effect of certain medications.

Control of gingival inflammation in a teenager population using ultrasonic prophylaxis

Gingival inflammation is clinically characterized by gingival redness, swelling and increased tendency of bleeding of the soft tissue. Bacterial biofilm is the etiological agent. If, at this stage, the bacterial biofilm is removed and appropriate control methods are applied, remission of gingival inflammation occurs. This study evaluated the effectiveness of a single session of ultrasonic prophylaxis for the reduction of gingivitis in an adolescent population using the Plaque Index (PI) and Gingival Index (GI). The study sample consisted of 15 male adolescent students selected at a dentist's office of a public high school. Prior to treatment (baseline), plaque index (PI) and bleeding on probing (BOP) were recorded. The patients then received oral hygiene instructions and ultrasonic prophylaxis. Follow-up exams were made 15 and 30 days after the ultrasonic prophylaxis, again recording PI and BOP. The data were analyzed by the Student's t-test for dependent samples. Correlation analysis between presence of biofilm and bleeding on probing was also made using the Pearson correlation test. There was a statistically significant decrease in the plaque index and bleeding on probing between baseline and examinations at both 15 days and 30 days (p<0.05). However, the difference between the means at 15 and 30 days was statistically similar. The correlation analysis showed correlation between both parameters (p<0.05). The results indicate that a single session of ultrasonic prophylaxis associated to oral hygiene instructions is efficient to reverse gingivitis in adolescents.

Occurrence of periodontal bacteria in healthy children: a 2-year longitudinal study

OBJECTIVES

To examine the occurrence of specific periodontal bacteria in children and adolescents.

METHODS

Ten putative periodontal bacteria were longitudinally examined in plaque and saliva samples from 119 periodontally healthy children (2-15 years old) using a polymerase chain reaction method.

RESULTS

Capnocytophaga ochracea, C. sputigena, and Actinobacillus actinomycetemcomitans were frequently found in saliva, and tended to persist in saliva for the remainder of the study, whereas Porphyromonas gingivalis, Treponema denticola, and Prevotella intermedia were rarely detected. P. nigrescens was more frequently detected in plaque and its prevalence increased with age. Eikenella corrodens and Campylobacter rectus were sometimes detected in both plaque and saliva, while Tannerella forsythensis was occasionally detected in saliva.

CONCLUSION

A. actinomycetemcomitans, C. ochracea, C. sputigena, P. nigrescens, C. rectus, and E. corrodens are common members of the oral microbial flora of healthy children, whereas P. gingivalis, P. intermedia, and T. denticola appear to be transient organisms.