Gingival fibroblast activation by Porphyromonas gingivalis is driven by TLR2 and is independent of the LPS-TLR4 axis.

Gingival fibroblasts (GFs) are abundant structural cells of the periodontium that contribute to the host's innate immunity by producing cytokines and chemokines in response to oral pathogens, such as Porphyromonas gingivalis. Isolated lipopolysaccharide (Pg-LPS) is commonly used to study GF responses to P. gingivalis; however, this approach produced conflicting observations regarding its proinflammatory potential and the engagement of specific Toll-like receptors (TLRs). In this work, we demonstrate that commercially available Pg-LPS preparations are weak activators of GF innate immune responses compared with live P. gingivalis or other relevant virulence factors, such as P. gingivalis fimbriae or LPS from Escherichia coli. GF's nonresponsiveness to Pg-LPS can be only partly attributed to the low expression of TLR4 and its accessory molecules, CD14 and LY36, and is likely caused by the unique structure and composition of the Pg-LPS lipid A. Finally, we combined gene silencing and neutralizing antibody studies to demonstrate that GF response to infection with live P. gingivalis relies predominantly on TLR2. In contrast, the LPS-TLR4 signaling plays a negligible role in inflammatory cytokine production by GFs exposed to this oral pathogen, confirming that Pg-LPS stimulation is not an optimal model for studies of GF responses to P. gingivalis.

Mapping of DNA methylation-sensitive cellular processes in gingival and periodontal ligament fibroblasts in the context of periodontal tissue homeostasis.

Interactions between gingival fibroblasts (GFs) and oral pathogens contribute to the chronicity of inflammation in periodontitis. Epigenetic changes in DNA methylation are involved in periodontitis pathogenesis, and recent studies indicate that DNA methyltransferase (DNMT) inhibitors may protect against epithelial barrier disruption and bone resorption. To assess the impact of DNMT inhibition on GFs, cells were cultured with decitabine (5-aza-2'-deoxycytidine, DAC) for 12 days to induce DNA hypomethylation. We observed several potentially detrimental effects of DAC on GF biological functions. First, extended treatment with DAC reduced GF proliferation and induced necrotic cell death. Second, DAC amplified Porphyromonas gingivalis- and cytokine-induced expression and secretion of the chemokine CCL20 and several matrix metalloproteinases (MMPs), including MMP1, MMP9, and MMP13. Similar pro-inflammatory effects of DAC were observed in periodontal ligament fibroblasts. Third, DAC upregulated intercellular adhesion molecule-1 (ICAM-1), which was associated with increased P. gingivalis adherence to GFs and may contribute to bacterial dissemination. Finally, analysis of DAC-induced genes identified by RNA sequencing revealed increased expression of CCL20, CCL5, CCL8, CCL13, TNF, IL1A, IL18, IL33, and CSF3, and showed that the most affected processes were related to immune and inflammatory responses. In contrast, the genes downregulated by DAC were associated with extracellular matrix and collagen fibril organization. Our observations demonstrate that studies of DNMT inhibitors provide important insights into the role of DNA methylation in cells involved in periodontitis pathogenesis. However, the therapeutic potential of hypomethylating agents in periodontal disease may be limited due to their cytotoxic effects on fibroblast populations and stimulation of pro-inflammatory pathways.

Impact of dietary habits on the incidence of oral diseases.

BACKGROUND: Diet is a factor that can modify the course of caries, dental erosion and periodontal diseases. OBJECTIVES: The aim of this study was to examine the impact of dietary habits and the anthropometric parameters on oral health. MATERIAL AND METHODS: 50 females and 45 males aged 19-21 years were examined in a cross-sectional study. Oral health was assessed utilizing selected dental indices: approximal plaque index (API), bleeding on probing (BoP), community periodontal index (CPI), and DMFT (D - decayed, M - missing, F - filled, T - teeth). In addition, dental erosion was assessed. Anthropometric measurements included body mass, height, body mass index (BMI), waist circumference, skinfold thickness, fatty and lean body mass, body fat percentage, and total body water. The frequency of consumption of food products was determined with the use of the Questionnaire on Food Products Frequency Intake. Student's t tests, the χ2 tests and Pearson's correlation coefficients were used to analyze the results. RESULTS: The average DMFT was 9.92, API was 52.97% and BoP was 20.46%. Dental erosion was observed in 44.21% of cases. A total of 11.58% of the study population were classified as CPI 0, 30.53% as CPI 1 and 57.89% as CPI 2. The consumption of crisps and cereal products increased caries (p = 0.003). Dental erosion was associated with the consumption of fruit, vegetables, meat, fish, and alcoholic beverages. The consumption of sugar, sweets and alcoholic beverages increased API and BoP. Caries rarely occurred in people who ate fruit and vegetables on a daily basis. The anthropometric parameters were associated with oral hygiene, gingivitis and body weight disorders (p < 0.05). CONCLUSIONS: Rational nutrition not only plays a role in the development of general systemic diseases, but also has an effect on oral health. Besides providing instructions on oral hygiene, dentists should also assess the eating habits of their patients.

hTERT-immortalized gingival fibroblasts respond to cytokines but fail to mimic primary cell responses to Porphyromonas gingivalis.

In periodontitis, gingival fibroblasts (GFs) interact with and respond to oral pathogens, significantly contributing to perpetuation of chronic inflammation and tissue destruction. The aim of this study was to determine the usefulness of the recently released hTERT-immortalized GF (TIGF) cell line for studies of host-pathogen interactions. We show that TIGFs are unable to upregulate expression and production of interleukin (IL)-6, IL-8 and prostaglandin E2 upon infection with Porphyromonas gingivalis despite being susceptible to adhesion and invasion by this oral pathogen. In contrast, induction of inflammatory mediators in TNFα- or IL-1ß-stimulated TIGFs is comparable to that observed in primary GFs. The inability of TIGFs to respond directly to P. gingivalis is caused by a specific defect in Toll-like receptor-2 (TLR2) expression, which is likely driven by TLR2 promoter hypermethylation. Consistently, TIGFs fail to upregulate inflammatory genes in response to the TLR2 agonists Pam2CSK4 and Pam3CSK4. These results identify important limitations of using TIGFs to study GF interaction with oral pathogens, though these cells may be useful for studies of TLR2-independent processes. Our observations also emphasize the importance of direct comparisons between immortalized and primary cells prior to using cell lines as models in studies of any biological processes.

Clinical crown lengthening - a case report.

Maintaining healthy parodontium during teeth restoration procedures is an indispensable condition for obtain- ing regular functionning and esthetics. Thus, the knowledge of correct anatomy and the influence of filling and complement on paradontium tissue is vital. Difficulty in maintaining appropriate gingival biological width (GBW) is a frequent problem encountered in this type of reconstruction. Preservation of unchanged biological width conditions predictible treatment result and, what is more, lack of inflammatory lesions in marginal parodontium. The ideal situation for parodontium is localizing the filling/complement border supragingivaly, which is at least 3 mm from alveolar process edge. In the case, when the above conditions are impossible to fulfil, elongation of clinical crown is a metod of choice. The effect is possible to achieve by surgical treatment or combined orthodontic - surgical treatment. Surgical treatment is faster and preferred procedure for indirect reconstruction, where achieving high clinical crown is necessary. Three clinical cases of performing method of surgical clinical crown elongation were presented in the article. Performing the described procedure enables correct tooth crown reconstruction and, what is most important, keeping individual toothing.

Mandible - clinically revisited.

Based on the current literature authors revised anatomical and clinical datas considering the mandible.

Controversies on the position of the mandibular foramen - review of the literature.

Foramen of mandible is the most important point considering the Halsted anesthesia. Position of this foramen seems to be stable, however there are lots of controversies regarded to its position. Based on the current literature authors revised datas from literature considering the location of the mandibular foramen.

Anatomy of the pterygomandibular space - clinical implication and review.

AIM: The aim of this study was to present review of the pterygomandibular space with some referrals to clinical practice, specially to the methods of lower teeth anesthesia. CONCLUSIONS: Pterygomandibular space is a clinically important region which is commonly missing in anatomical textbooks. More attention should be paid to it both from theoretical and practical point of view, especially in teaching the students of first year of dental studies.