Evaluation of cutting efficiency and thermal damage during soft tissue surgery with 940 nm-diode laser: An ex vivo study.

OBJECTIVES: To investigate quantitatively the cutting efficiency and the thermal effects in the surrounding soft tissues of incisions that are induced by a 940 nm-diode laser with different power settings. MATERIALS AND METHODS: Fifty-four gingival samples were prepared from the lower jaws of freshly slaughtered German-land race pigs and were randomly divided into 9 groups (n = 6) according to the adjusted output power (1, 1.5, 2, 2.5, 3, 3.5, 4, 5 and 6 W). Five incisions were implemented for each sample using a diode laser (940 nm) in continuous wave with an initiated tip resulting in 30 incisions for each experimental group utilizing a three-dimensional computer-controlled micropositioner. The samples were prepared for histometric evaluation using a transmitted light microscope. The cutting depth and width and the thermal damage were recorded for each sample and the efficiency factor γ was calculated. RESULTS: The highest cutting efficiency (γz = 0.81 ± 0.03) exhibited the group with 5 W output power (p < 0.05), while the lowest (γz = 0.45 ± 0.11) showed the 1-W group (p < 0.05). Over 3.5 W there was a rapid increase in the size of thermal damage of the incisions, especially for 6 W, which presented the largest. CONCLUSIONS: The most effective power parameters of diode laser (940 nm) for soft tissue surgery were from 3 to 5 W. The outcomes of the current study may help to establish clinical protocols for the use of diode lasers (940 nm) in soft tissue surgery in contact mode assisting dental professionals to achieve optimal clinical results and avoid complications.

Expression profile of lipoxygenases in gingival tissues of human periodontitis.

OBJECTIVES: This study aimed to clarify the expression profile and significance of lipoxygenases in periodontitis. MATERIALS AND METHODS: The mRNA levels of lipoxygenases in gingival tissues from 14 patients with periodontitis and 14 healthy individuals were determined by real-time PCR, and validated in datasets, GSE16134 and GSE10334, and by Western blotting. Correlation of differentially expressed lipoxygenases with clinical parameters and expression of tumor necrosis factor-α (TNF-α), interleukin-1ß, matrix metalloproteinase (MMP)-8, MMP-9, and receptor activator of nuclear factor-κB ligand (RANKL) was investigated in patients with periodontitis by Spearman's correlation analysis. RESULTS: The expression of ALOX5 (2.1-fold, p < .05), ALOX12B (2.9-fold, p < .001), and ALOX15B (9.4-fold, p < .001) was upregulated in gingival tissues from patients with periodontitis, which was validated by dataset analysis and Western blotting. Positive correlations were observed between ALOX5 and probing depth, and ALOX15B and probing depth and clinical attachment loss. Furthermore, ALOX5 expression was positively correlated with TNF-α, MMP-8, MMP-9, and RANKL expression, and ALOX15B was positively correlated with MMP-8 and RANKL. CONCLUSIONS: Our findings indicated the upregulation of ALOX5 and ALOX15B in periodontitis and suggested that ALOX5 and ALOX15B may be involved in periodontitis pathogenesis, including inflammation, connective tissue destruction, and abnormal bone metabolism.

INFLUENCE OF MICROBIOTA ON THE CLINICAL AND IMMUNO-HISTOCHEMICAL CHARACTERISTICS OF CHRONIC GENERALIZED CATARRHAL GINGIVITIS IN CHILDREN.

OBJECTIVE: The aim: The purpose of the study is to characterize the influence of quantitative and qualitative composition of gingival microbiota on the status of the main immune system cells, localized in the gums, in chronic generalized catarrhal gingivitis in children. PATIENTS AND METHODS: Materials and methods: The study involved 26 children aged 9 to 16 years, patients with chronic generalized catarrhal gingivitis mild to moderate severity (CGCG) and 18 children with intact gums were comparison group. We determined the hygienic indices Fedorov, has been received, Silness-Loe, PMA, bleeding index for Myuleman and intensity of caries index CFD + cf, CFD. Histological and immunohistochemical studies were performed on serial sections kriostatnyh who made biopsy of gingival papillae. Microbiological study gingival part of crown plaque was performed by multiplexed PCR in real time. RESULTS: Results: Value hygienic indices in children with CGCG higher than in healthy, indicating the difficulty of care in the presence of periodontal inflammation. As a result of immunohistochemical studies revealed that HLA-DR + cells under conditions of active disease migrate to mucosal lamina propria epithelium. Number of CD3 + cells in the epithelium CGCG was significantly higher than the number in the intact epithelium and was the most numerous of population. In the biopsy of affected children significantly reduced the number of CD4 + cells. When CGCG quantitative total bacterial mass, Lactobacillus spp., Enterobacteriaceae, Gardnerella vaginalis / Prevotella bivia / Porphyromonas spp. in the sample CROWN dental plaque was significantly higher than rates under physiological conditions, and may serve as diagnostic criteria of dysbiosis. CONCLUSION: Conclusions: So, CGCG is a disease in the etiology of which is one of the leading roles played by microbial factor, namely, the value of the quantitative ratios of certain types of microorganisms of dental plaque compared to the total bacterial mass of plaque. Therefore, it is reasonable to include comprehensive treatment CGCG drugs in children, leading to natural immunostimulation which causes restoration of local immunity in the gum tissue and drugs to restore quantitative and qualitative composition of normal microflora of the child, thus providing a high therapeutic effect and serve as justification their choice.

Human Gingival Integration-Free iPSCs; a Source for MSC-Like Cells.

Mesenchymal stem cells (MSCs) are considered a potential autologous therapy for tissue engineering. The available procedures for MSC retrieval from patients are invasive, and their limited in vitro proliferation restricts their use in the treatment of damaged tissues. Therefore, it is important to establish an alternative and safe source of MSCs. The objective of this study was to demonstrate induced pluripotent stem cell (iPSC) generation from a combination of an accessible source tissue and an integration-free method; we also attempted the differentiation of iPSCs into MSC-like cells (MSLCs) for future autologous tissue engineering. iPSCs were derived from human gingival tissues, which are easily accessible in the field of dentistry, via the use of non-integrating episomal plasmids. Established iPSCs expressed embryonic stem (ES) cell-specific markers, as assessed by gene analysis and immunocytochemistry. Embryoid bodies and teratoma formation were formed from iPSCs, showing their capacity to differentiate into three germ layers. Furthermore, we were successful in differentiating iPSCs into MSLCs. They tested positively for their capacity of trilineage differentiation. Our results demonstrate that human gingival integration-free iPSCs, readily accessible stem cells generated using episomal plasmid vectors, are a promising source of MSLCs, which can be used in tissue regeneration.

Differential expression of transglutaminase genes in patients with chronic periodontitis.

OBJECTIVE: Gingival epithelium plays a key role in the protection of oral tissues from microbial challenge, especially during the periodontal disease. This study was aimed to evaluate levels of mRNA transcripts of different forms of transglutaminase in the human gingival tissues from patients with chronic periodontitis and relative controls. SUBJECTS AND METHODS: This study included 22 patients with chronic periodontitis (CP) and 22 healthy controls. For each patient, the values of probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were recorded. Gene expression of transglutaminase 1, transglutaminase 2, transglutaminase 3, and metalloprotease 2 was evaluated by real-time PCR, while that of Factor XIIIA and metalloprotease 9 by RT-PCR. RESULTS: The values of all the clinical parameters were significantly higher in the CP group than in the healthy control group (P < 0.05). In the CP group, the mRNA expression of transglutaminase 1 and transglutaminase 3 was significantly decreased in comparison with healthy control group. A slight nonsignificant changes of transglutaminase 2 gene expression were observed in samples from CP patients in comparison with controls. CONCLUSIONS: These observations suggest that transglutaminase gene expression may be modified in response to chronic injury in the damaged gingival and emphasizes the key role of these enzymes in gingival remodelling/healing and adaptive processes.

Delving into Matrix Metalloproteinase-1 (MMP-1) and its Significance in Periodontal Diseases.

Matrix metalloproteinase-1 (MMP-1) plays a pivotal role in the pathogenesis of periodontal diseases, particularly periodontitis, by virtue of its collagenolytic activity targeting collagen type I, the primary component of periodontal tissues. This review abstract elucidates the intricate involvement of MMP-1 in periodontal tissue homeostasis and its dysregulation in disease states. Elevated MMP-1 levels, observed in gingival tissues and crevicular fluid of individuals with periodontitis, correlate with the degradation of collagen fibers within the periodontium. This degradation contributes to the detachment of teeth from surrounding tissues and exacerbates alveolar bone resorption, hallmark features of periodontal breakdown. Therapeutically, targeting MMP-1 activity emerges as a promising strategy, prompting ongoing research into MMP inhibitors and host modulation therapies. Understanding MMP-1's nuanced role in periodontal diseases paves the way for personalized treatment approaches and holds promise in reshaping periodontal disease management for improved patient outcomes and periodontal health.

Influence of hyperocclusion on the remodeling of gingival tissues.

OBJECTIVE: The purpose of this study was to observe the effect of hyperocclusion on the remodeling of gingival tissues and detect the related signaling pathways. DESIGN: Hyperocclusion models were established by tooth extraction in mice. The mice were sacrificed at 3, 7, 14, 28, or 56 days after the surgery, and the left mandibular first molars with gingival tissues were isolated and examinations were focused on the gingival tissues. Apoptotic cells were examined using terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) technology. Proliferating cells, p65, inflammatory cytokines, and ß-catenin were detected using immunohistochemical methods. RESULTS: A series of apoptosis and proliferation responses were triggered in stressed gingival tissues. It was observed that the levels of p65, proinflammatory factors including interleukin-1ß and tumor necrosis factor-α in extraction group were higher compared with those from mice with intact dentition, and peaked on days 14, 14 and 7 respectively. The expression of ß-catenin was increased under hyperocclusion situations, peaked on day 14, and declined to the initial levels over time. CONCLUSIONS: The results of this study suggest that hyperocclusion causes remodeling of the gingival tissues by activating a series of adaptive responses. Both nuclear factor kappa B and Wnt/ß-catenin signaling pathways may be responsible for those adaptive responses though the exact mechanism is not clear.

Beneficial Effects of Glycyrrhizin in Chronic Periodontitis Through the Inhibition of Inflammatory Response.

Elevated inflammatory cytokines and high mobility group box 1 (HMGB1) production are associated with chronic periodontitis (CP). Glycyrrhizin is the major constituent of Glycyrrhiza glabra. L. (Fabaceae) root with anti-inflammation activities. This study evaluated the effects of glycyrrhizin on CP. TNF-α-treated human periodontal ligament stem cell (hPDLSC) model was established, and was administrated with 1, 2 or 5 mM glycyrrhizin for 24 h. After treatment, the expression of HMGB1and inflammatory cytokines was monitored. Significantly increased HMGB1 (median: 5646.4, range: 1918.2-8233.7 vs median: 204.5, range: 98.7-283.6, pg/mL), TNF-α (median: 345.5, range: 161.0-567.9 vs median: 93.5, range: 58.1-159.3, pg/mL), IL-1ß (median: 2014.6, range: 209.5-4308.1 vs median: 224.5, range: 48.8-335.8, pg/mL) and IL-6 (median: 1223.6, range: 398.2-2183.8 vs median: 240.4, range: 105.2-400.5, pg/mL) were detected in gingival crevicular fluid from CP patients. Glycyrrhizin significantly prevented TNF-α-induced expression of HMGB1 (691.5 ± 136.4 vs 142.8 ± 57.3 pg/mL), IL-6 (388.1 ± 85.2 vs 189.4 ± 61.2 pg/mL) and IL-1ß (176.3 ± 47.2 vs 53.9 ± 25.7 pg/mL) in hPDLSC. In CP rats, glycyrrhizin significantly decreased HMGB1 (5795.6 ± 1121.5 vs 586.4 ± 436.8 pg/mL), TNF-α (421.8 ± 93.7 vs 87.9 ± 21.6 pg/mL), IL-6 (1423.8 ± 235.2 vs 622.6 ± 176.1 pg/mL) and IL-1ß (1562.8 ± 334.3 vs 733.5 ± 265.1 pg/mL) in gingival crevicular fluid. Glycyrrhizin suppresses inflammatory activities in CP rats and represents a promising molecule for controlling CP.

Determining the time of death by morphological and immunohistochemical evaluation of collagen fibers in postmortem gingival tissues.

The estimation of the post mortem interval (PMI) is still one of the most challenging variables to determine and the different approaches currently used in its estimation generally yield to large post mortem windows. In the present study we combined morphological and immunohistochemical analysis in order to reach a more detailed knowledge on tissue organization and degradation after death. Ultrastructural cellular changes and the extracellular matrix of gingival tissues, collected at different post mortem intervals, were observed by a Transmission Electron Microscopy (TEM), in combination with the immunohistochemical detection of extracellular matrix proteins (i.e. collagen type I and collagen type III) as potential post mortem biochemical markers. The final goal was to find a correlation between morphological modifications, biomarkers expression and the time of death. Samples of gingival tissues obtained from 10 cadavers at different post mortem intervals (short post mortem interval, 1-3 days; mid post mortem interval, 4-6 days; long post mortem interval, 7-9 days) were processed for light microscopy and TEM and they were also immunostained with anti-collagen type I and type III antibodies. Results showed gradual degradation of extracellular matrix in the suboral connective tissue in relation to the different time of death. Moreover PMI was related to an increase of nuclear chromatin condensation and cytoplasmic vacuolization both in epithelial and connective tissues. In conclusion, in addition to traditional forensic approaches to estimate PMI, the combined analyses of cellular morphology, ultrastructure and immunohistochemical expression of collagen proteins allow to better infer the PMI.

Expression of ß-catenin and MMP-8 in gingival crevicular fluid and gingival tissue indicates the disease severity of patients with chronic periodontitis.

The aim of the present study was to investigate the interaction among ß-catenin, matrix metalloproteinase-8 (MMP-8) and severity in patients with chronic periodontitis. Both gingival crevicular fluid (GCF) and gingival tissue was collected from 21 healthy control individuals, 21 patients with moderate chronic periodontitis (mCP) and 23 patients with severe chronic periodontitis (sCP). The concentration of MMP-8 in GCF was detected via ELISA and the mRNA levels of ß-catenin and MMP-8 in GCF and gingival tissue was detected via reverse transcription-quantitative PCR. The protein levels of ß-catenin and MMP-8 in gingival tissue was detected using western blotting and the interaction between ß-catenin and MMP-8 in gingival tissue was detected by co-immunoprecipitation. The expression of ß-catenin and MMP-8 was significantly higher in the GCF and gingival tissue of patients with chronic periodontitis (mCP and sCP) compared with the control patients. Furthermore, the expression of ß-catenin and MMP-8 in GCF and gingival tissue was positively correlated with the clinical attachment level. In addition, a positive interaction was identified between ß-catenin and MMP-8, and the expression of ß-catenin was positively correlated with the expression of MMP-8 in GCF and gingival tissue. The CGF and gingival tissue expression of ß-catenin and MMP-8 may indicate disease severity in patients with chronic periodontitis.

Transcriptome Analysis of B Cell Immune Functions in Periodontitis: Mucosal Tissue Responses to the Oral Microbiome in Aging.

Evidence has shown activation of T and B cells in gingival tissues in experimental models and in humans diagnosed with periodontitis. The results of this adaptive immune response are noted both locally and systemically with antigenic specificity for an array of oral bacteria, including periodontopathic species, e.g., Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. It has been recognized through epidemiological studies and clinical observations that the prevalence of periodontitis increases with age. This report describes our studies evaluating gingival tissue transcriptomes in humans and specifically exploiting the use of a non-human primate model of naturally occurring periodontitis to delineate gingival mucosal tissue gene expression profiles focusing on cells/genes critical for the development of humoral adaptive immune responses. Patterns of B cell and plasmacyte genes were altered in aging healthy gingival tissues. Substantial increases in a large number of genes reflecting antigen-dependent activation, B cell activation, B cell proliferation, and B cell differentiation/maturation were observed in periodontitis in adults and aged animals. Finally, evaluation of the relationship of these gene expression patterns with those of various tissue destructive molecules (MMP2, MMP9, CTSK, TNFα, and RANKL) showed a greater frequency of positive correlations in healthy tissues versus periodontitis tissues, with only MMP9 correlations similar between the two tissue types. These results are consistent with B cell response activities in healthy tissues potentially contributing to muting the effects of the tissue destructive biomolecules, whereas with periodontitis this relationship is adversely affected and enabling a progression of tissue destructive events.

Evaluation of TLR2 and 4 in Chronic Periodontitis.

INTRODUCTION: Periodontal disease is the major cause of adult tooth loss and is commonly characterized by a chronic inflammation caused by infection due to oral bacteria. Members of Toll-Like Receptor (TLR) family recognize conserved microbial structures, such as bacterial lipopolysaccharides and activate signalling pathways that result in immune responses against microbial infections. AIM: The aim of the present study was to assess the mRNA expression of Toll-Like Receptor 2 and 4 in tissues with or without chronic periodontitis. MATERIALS AND METHODS: Gingival tissue samples were collected from controls (30 subjects with healthy periodontal tissues) and experimental group (30 subjects with chronic periodontitis). Total RNA was extracted and RT-PCR was done for evaluation of TLR-2 and TLR-4. Mann Whitney U-test, Pearson Chi-square Test was used for statistics. RESULTS: The results showed that there is a significant (p-value= 0.004) association between TLR-4 and the experimental group comprising of chronic periodontitis patients in comparison to the insignificant (p-value= 0.085) TLR-2 expression. CONCLUSION: This study concludes that TLR-2 and TLR-4 expressed in the gingival tissues recognize different bacterial cell wall components thus helping us to associate its potential in diagnosing periodontal disease. Hence, in the future, these scientific findings can pave the way in using TLR as a diagnostic biomarker for periodontal disease.

Biomechanical Characteristics of Collagen Fibrils of Human Free Gingival Tissues- Atomic Force Microscope Study

@#The information of biomechanical properties is crucial in the study of biological tissue and its clinical relevance. 3mm x 3mm free gingival human tissues was taken using disposable punch biopsy (Accu sharp blade, India) and stored in 0°C Freezer. The sample was sectioned to a thickness of 10μm using high profile microtome blade (Leica 818, Germany) and cryostat (Leica CM1850UV, United Kingdom). The sample was analysed using Atomic Force Microscope (Nanowizard® 3, JPK Instruments, Germany) at room atmosphere. The collagen fibrils of the free gingival tissues appeared to be stacked in basket weave like structure. The mean value of free gingival collagen fibrils width and the length of D-band were 106.71±11.18nm and 65.82 ± 3.04nm respectively. The Young’s modulus of collagen fibrils for human free gingival tissue at overlap region was 212.88 ± 242.58 MPa, whereas at the gap region was 207.00 ± 230.71 MPa. Within the limitation of the study, the collagen fibrils appeared to be stacked in basket weave-like structure. The length and width of the collagen fibril were similar to the values investigated using other techniques. There was significant linear relationship between Young’s modulus of overlap and gap regions.

Isolated relapse in the oral cavity of a child with t-lineage acute lymphoblastic leukemia

Despite high cure rates, approximately 20% of patients with acute lymphoblastic leukemia (ALL) have disease relapse. Isolated recurrence in oral cavity is extremely unusual. The aim of this paper is to report a case of an isolated relapse occurred in a child with T-lineage ALL. Clinical picture included swelling and pain in the right upper gingiva of the oral cavity, with no other clinical or hematological alterations. Diagnosis was confirmed by biopsy and immunohistochemical staining. Bone marrow aspiration was normal. Five months later leukemic infiltration of the bone marrow was detected and systemic chemotherapy was reintroduced. This case report highlights the relevance of dental care during and after chemotherapy, not only to treat lesions in the oral cavity resulting from the disease itself or from treatment side effects, but also to detect unusual sites of ALL relapse.

Apesar dos altos índices de cura, cerca de 20% dos pacientes com leucemia linfóide aguda (LLA) apresentam recidiva da doença. Recidiva isolada na cavidade oral é extremamente incomum. O objetivo deste trabalho é relatar um caso de recidiva isolada em criança com LLA de linhagem T. A apresentação clínica foi quadro de edema e dor na cavidade oral, na região superior da gengiva à direita, sem outras alterações clínicas ou hematológicas. O diagnóstico foi confirmado por meio de biópsia e imuno-histoquímica. O mielograma era normal. Cinco meses após a manifestação inicial na cavidade oral, foi detectada infiltração leucêmica na medula óssea. O tratamento com quimioterapia sistêmica foi reintroduzido. Este relato de caso ressalta a importância do acompanhamento clínico e odontológico durante e após o tratamento quimioterápico, não somente com o objetivo de tratar as alterações na cavidade oral decorrentes da própria doença ou dos efeitos adversos do tratamento, mas para que sejam detectadas apresentações incomuns de recidiva na LLA.