O uso da proteína botulínica na correção do sorriso gengival / The use of botulinum protein in the correction of gingival smile

A sociedade está cada vez mais exigente e em busca de excelência quando o assunto é estética facial. O sorriso tem grande impacto na harmonia da face e, atualmente, os pacientes estão mais conscientes sobre a influência da gengiva na beleza do sorriso. A exposição da gengiva em excesso, conhecida como sorriso gengival, afeta a estética, podendo interferir na autoestima e nas relações sociais dos pacientes. Existem diversos procedimentos descritos para solucionar o problema e, para o planejamento do caso e escolha do método, é preciso determinar a etiologia e levar em consideração o desejo do paciente. A injeção da proteína botulínica é uma alternativa minimamente invasiva que está sedo cada vez mais utilizada para a correção do sorriso gengival. Com isso, o objetivo do presente trabalho monográfico foi realizar uma revisão de literatura sobre o uso da toxina botulínica na correção do sorriso gengival, analisando técnicas de injeção, identificando o efeito imediato e a longo prazo da toxina nos músculos elevadores do lábio superior, além de avaliar a relevância desse método na correção do sorriso gengival, sozinho ou em conjunto com outros procedimentos. Foi realizada uma revisão de literatura nas bases de dados PubMed e Scielo, buscando artigos dos anos de 2013 até 2022, utilizando os descritores "botulinum toxin", "botox", "gummy smile", "gingival display" e "gingival exposure". Essa revisão analisa 15 artigos que discorrem sobre o método, durabilidade e eficácia da aplicação de proteína botulínica para correção do sorriso gengival. Algumas variantes diferenciam as técnicas de aplicação, como a marca do produto e recomendações do fabricante, classificação do sorriso e extensão da exposição gengival. Com base na revisão de literatura, pôde-se concluir que, apesar de ser transitório, esse procedimento se mostrou eficaz, tanto ao ser realizado como método principal, quanto como coadjuvante no tratamento. Além de ser comprovadamente seguro, rápido, minimamente invasivo e ser o tratamento de preferência entre os pacientes, com alto índice de satisfação, são raras as complicações relacionadas a aplicação da proteína botulínica para esse fim.

Society is becoming increasingly demanding, seeking excellence in facial aesthetics. The smile greatly impacts facial harmony, and nowadays, patients are more aware of the influence of the gums on smile beauty. Excessive gum exposure, known as gummy smile, affects aesthetics and can interfere with patients' self-esteem and social relationships. There are various procedures described to address this issue, and for case planning and method selection, it is necessary to determine the etiology and take into account the patient's desires. The injection of botulinum protein is a minimally invasive alternative that is increasingly being used for gummy smile correction. Thus, the aim of this monographic work was to conduct a literature review on the use of botulinum toxin in gummy smile correction, analyzing injection techniques, identifying the immediate and long-term effects of the toxin on the upper lip elevator muscles, and evaluating the relevance of this method in gummy smile correction, either alone or in conjunction with other procedures. A literature review was conducted in the PubMed and Scielo databases, seeking articles from 2013 to 2022, using the descriptors "botulinum toxin", "botox", "gummy smile", "gingival display", and "gingival exposure". This review analyzes 15 articles that discuss the method, durability, and effectiveness of botulinum toxin application for gummy smile correction. Some variations differentiate the application techniques, such as the product brand and manufacturer's recommendations, smile classification, and extent of gum exposure. Based on the literature review, it was possible to conclude that, despite being temporary, this procedure proved to be effective, both when performed as the main method and as an adjunct in treatment. In addition to being proven safe, fast, minimally invasive, and the preferred treatment among patients, with a high satisfaction rate, complications related to botulinum toxin application for this purpose are rare.

Giant peripheral ossifying fibroma of gingiva: a diagnostic workup.

Reactive lesions of the oral cavity are non-neoplastic proliferations occurring due to chronic irritation. Peripheral ossifying fibroma (POF) is a reactive lesion usually occurring on the interdental papilla. POF is predominantly found in the second decade of life with a definitive female predilection. This is a case report of a middle-aged male patient with gingival overgrowth in left lower back tooth region. Clinically, the lesion was asymptomatic, firm, pale pink and sessile but unusually large in size. Surgical excision of the lesion was done followed by histopathological confirmation with emphasis on the diagnosis. The case in question is interesting because of its large size and location.

Dimethyl Fumarate-Loaded Gellan Gum Hydrogels Can Reduce In Vitro Chemokine Expression in Oral Cells.

Dimethyl fumarate (DMF), originally proposed to treat multiple sclerosis, is considered to have a spectrum of anti-inflammatory effects that effectively control periodontitis, mainly when applied with a hydrogel delivery system. Chemokine expression by gingival fibroblasts is a significant driver of periodontitis; thus, hydrogel-based strategies to deliver DMF, which in turn dampen chemokine expression, are of potential clinical relevance. To test this approach, we have established a bioassay where chemokine expression is induced by exposing gingival fibroblast to IL1ß and TNFα, or with saliva. We show herein that DMF effectively reduced the expression of CXCL8, CXCL1, CXCL2, and CCL2-and lowered the phosphorylation of ERK and JNK-without affecting cell viability. This observation was confirmed by immunoassays with CXCL8. Consistently, the forced chemokine expression in HSC2 oral squamous epithelial cells was greatly diminished by DMF. To implement our hydrogel-based delivery system, gingival fibroblasts were cocultured with gellan gum hydrogels enriched for DMF. In support of our strategy, DMF-enriched gellan gum hydrogels significantly reduced the forced chemokine expression in gingival fibroblasts. Our data suggest that DMF exerts its anti-inflammatory activity in periodontal cells when released from gellan gum hydrogels, suggesting a potential clinical relevance to control overshooting chemokine expression under chronic inflammatory conditions.

Mesenchymal Stem/Stromal Cells Derived from Dental Tissues Mediate the Immunoregulation of T Cells through the Purinergic Pathway.

Human dental tissue mesenchymal stem cells (DT-MSCs) constitute an attractive alternative to bone marrow-derived mesenchymal stem cells (BM-MSCs) for potential clinical applications because of their accessibility and anti-inflammatory capacity. We previously demonstrated that DT-MSCs from dental pulp (DP-MSCs), periodontal ligaments (PDL-MSCs), and gingival tissue (G-MSCs) show immunosuppressive effects similar to those of BM, but to date, the DT-MSC-mediated immunoregulation of T lymphocytes through the purinergic pathway remains unknown. In the present study, we compared DP-MSCs, PDL-MSCs, and G-MSCs in terms of CD26, CD39, and CD73 expression; their ability to generate adenosine (ADO) from ATP and AMP; and whether the concentrations of ADO that they generate induce an immunomodulatory effect on T lymphocytes. BM-MSCs were included as the gold standard. Our results show that DT-MSCs present similar characteristics among the different sources analyzed in terms of the properties evaluated; however, interestingly, they express more CD39 than BM-MSCs; therefore, they generate more ADO from ATP. In contrast to those produced by BM-MSCs, the concentrations of ADO produced by DT-MSCs from ATP inhibited the proliferation of CD3+ T cells and promoted the generation of CD4+CD25+FoxP3+CD39+CD73+ Tregs and Th17+CD39+ lymphocytes. Our data suggest that DT-MSCs utilize the adenosinergic pathway as an immunomodulatory mechanism and that this mechanism is more efficient than that of BM-MSCs.

SIRT6 alleviates senescence induced by Porphyromonas gingivalis in human gingival fibroblasts.

OBJECTIVE: Bidirectional influences between senescence and inflammation are newly discovered. This study aimed to clarify the roles and mechanism of Porphyromonas gingivalis (P. gingivalis) in exacerbating senescence in human gingival fibroblasts (HGFs). DESIGN: Subgingival plaque and gingivae were collected from twenty-four periodontitis patients and eighteen periodontally healthy subjects. Quantities of P. gingivalis in subgingival plaque were explored using real-time PCR and the expressions of p53, p21 and SIRT6 in gingivae were detected by IHC. Moreover, senescence in HGFs was induced by P. gingivalis lipopolysaccharide (LPS) and the expressions of senescence-related ß-galactosidase (SA-ß-gal), p53, p21 and senescence-associated secretory phenotype (IL-6 and IL-8) with or without treatment by SIRT6 activator UBCS039 were explored by IHC, western blot and ELISA, respectively. In addition, the levels of SIRT6, Nrf2, HO-1 and reactive oxygen species (ROS) were examined by western blot and flow cytometry. RESULTS: Quantities of P. gingivalis in subgingival plaque and semi-quantitative scores of p53 and p21 in gingivae of periodontitis patients were increased compared with healthy controls (p < 0.05), while SIRT6 score in periodontitis patients was decreased (p < 0.001). Quantities of P. gingivalis were positively correlated with p53 and p21 scores (0.6 < r < 0.9, p < 0.01), and negatively correlated with SIRT6 score (-0.9 < r<-0.6, p < 0.01). Moreover, P. gingivalis LPS increased the levels of SA-ß-gal, p53, p21, IL-6, IL-8 and ROS and decreased the levels of SIRT6, Nrf2 and HO-1 in HGFs, which was rescued by UBCS039 (p < 0.05). CONCLUSIONS: P. gingivalis LPS could induce senescence of HGFs, which could be reversed by SIRT6 via Nrf2-HO-1 signaling pathway.

Cytotoxicity of two fluoride-releasing adhesive tapes.

Sodium fluoride-polyvinyl alcohol (NaF-PVA) tape was developed to deliver fluoride to teeth by adding fluoride to polymer tape. Previous studies have demonstrated that tapes are effective and have antimicrobial properties. This study aimed to evaluate the cytotoxicity of two fluoride-releasing adhesive tapes. We investigated two polyvinyl alcohol (PVA) tapes: (i) a fluoride-PVA (F-PVA) tape, and (ii) a pullulan-incorporated F-PVA (PF-PVA) tape. The cytotoxicity test was conducted on human gingival fibroblasts (HGF) and human periodontal ligament (PDL) cells. Using an adhesive tape containing fluoride, we performed the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on these cells. Genetic analysis of the cells was performed to conduct a stability test on humans. In the MTT assay, PF-PVA had 66% greater cytotoxicity than control by PDL and 69% by HGF. F-PVA showed less cytotoxicity than PF-PVA by 29% in PDL and 33% in HGF. Gene ontology (GO) analysis and gene set enrichment analysis (GSEA) were performed as gene expression analyses. GO analysis indicated that PF-PVA displayed more expression changes of genes related to cytotoxicity than F-PVA. In addition, GSEA found more inflammatory response associations in PF-PVA than in F-PVA. MTT and genetic testing yielded comparable results.

Autologous hGMSC-Derived iPS: A New Proposal for Tissue Regeneration.

The high mortality in the global population due to chronic diseases highlights the urgency to identify effective alternative therapies. Regenerative medicine provides promising new approaches for this purpose, particularly in the use of induced pluripotent stem cells (iPSCs). The aim of the work is to establish a new pluripotency cell line obtained for the first time by reprogramming human gingival mesenchymal stem cells (hGMSCs) by a non-integrating method. The hGMSC-derived iPS line characterization is performed through morphological analysis with optical and electron scanning microscopy and through the pluripotency markers expression evaluation in cytofluorimetry, immunofluorescence, and RT-PCR. To confirm the pluripotency of new hGMSC-derived iPS, the formation of embryoid bodies (EBs), as an alternative to the teratoma formation test, is studied in morphological analysis and through three germ layers' markers' expression in immunofluorescence and RT-PCR. At the end, a comparative study between parental hGMSCs and derived iPS cells is performed also for the extracellular vesicles (EVs) and their miRNA content. The new hGMSC-derived iPS line demonstrated to be pluripotent in all aspects, thus representing an innovative dynamic platform for personalized tissue regeneration.

The Clinical Effect of a Propolis and Mangosteen Extract Complex in Subjects with Gingivitis: A Randomized, Double-Blind, and Placebo-Controlled Clinical Trial.

This study investigated the efficacy and safety of a propolis-mangosteen extract complex (PMEC) on gingival health in patients with gingivitis and incipient periodontitis. A multicentered, randomized, double-blind, placebo-controlled trial involving 104 subjects receiving either PMEC or placebo for eight weeks was conducted. The primary focus was on the changes in inflammatory biomarkers from gingival crevicular fluid (GCF), with clinical parameters as secondary outcomes. The results revealed that the PMEC group showed a significantly reduced expression of all measured GCF biomarkers compared to the placebo group (p < 0.0001) at 8 weeks, including substantial reductions in IL-1ß, PGE2, MMP-8, and MMP-9 levels compared to the baseline. While clinical parameters trended towards improvement in both groups, the intergroup differences were not statistically significant. No significant adverse events were reported, indicating a favorable safety profile. These findings suggest that PMEC consumption can attenuate gingival inflammation and mitigate periodontal tissue destruction by modulating key inflammatory mediators in gingival tissue. Although PMEC shows promise as a potential adjunctive therapy for supporting gingival health, the discrepancy between biomarker improvements and clinical outcomes warrants further investigation to fully elucidate its therapeutic potential in periodontal health management.

Oral biopsy in mucous membrane pemphigoid and pemphigus vulgaris with gingival expression: the optimal site. A systematic review and meta-analysis.

PURPOSE: In order to diagnose mucous membrane pemphigoid (MMP) and pemphigus vulgaris (PV) with gingival expression, clinical data must be compared with immunohistochemical data obtained using direct immunofluorescence (DIF). It is therefore essential to carry out a good quality mucosal biopsy for this vital additional test. To date, no study has been able to effectively guide clinicians in their choice of oral site for biopsy to guarantee the efficient contribution of DIF to diagnosis. We propose a systematic review of the literature and a meta-analysis to clarify this issue. MATERIALS AND METHODS: Electronic databases and bibliographies of articles were searched in April 2023. The primary outcome was the rate of DIF + contribution to diagnosis according to the location of the oral site biopsied. RESULTS: 16 studies were included. Gingival biopsies showed a rate of DIF + 100% [97%-100%] p = 0.998 I2 = 0.0% with no heterogeneity for PV, and 90.2% [66.5%-100%] p < 0.001 I2 = 89.6% with high heterogeneity for MMP. For the other oral sites, this rate was 95.7% [87.4%- 100%] p = 0.011 I2 = 73.0% with moderate heterogeneity for PV, and 87.4% [70.1%- 98.7%] p < 0.001 I2 = 92.6% with high heterogeneity for MMP. In addition, meta-regression confirmed the significant association between the appearance of the biopsied mucosa and the rate of DIF + in MMP (p < 0.001), with no influence on residual heterogeneity. CONCLUSION: The nature of the oral mucosa biopsied does not influence the rate of DIF + to diagnosis. The choice of biopsy site should only take into account the characteristics of the clinical picture and the benefit/risk balance of the surgical protocol. The sample must be taken in healthy aeras as close as possible of active lesions: on the gingiva if the MMP and PV are strictly gingival, on the alveolar mucosa if the whole gingiva is altered and on any healthy mucosa if a large number of oral sites are affected. CLINICAL TRIALS: CRD42023392345.

Developing a novel calcium silver zeolite for caries management.

OBJECTIVE: To develop a novel calcium silver zeolite (Ca-Ag-Zeo) and assess its biocompatibility, physiochemical properties and antimicrobial effects. METHODS: Ca-Ag-Zeo was synthesized using ion-exchange method with calcium chloride, silver nitrate and Zeolite X (Zeo). Silver zeolite X (Ag-Zeo) and Zeo were set as control. The chemical structure, morphology, crystal structure and elemental composition of Ca-Ag-Zeo was characterized by X-ray diffraction spectrum, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy, respectively. Its biocompatibility on the human gingival fibroblasts was assessed by cell counting kit-8 assay. Its physiochemical properties were determined by the released calcium and silver ion using Inductive Coupled Plasma Emission Spectrometry for up to 12 weeks. The antimicrobial properties on Streptococcus mutans, Lactobacillus acidophilus, Lactobacillus casei, and Candida albicans were assessed by minimum bactericidal concentration (MBC) or minimum fungicidal concentration (MFC) assay. RESULTS: Ca-Ag-Zeo with a hexagonal cage structure was synthesized. As for biocompatibility, the half-maximal inhibitory concentration (± SD in mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo in human gingival fibroblasts were 0.52 ± 0.05, 0.15 ± 0.01 and 3.35 ± 0.58, respectively (Zeo > Ca-Ag-Zeo > Ag-Zeo; p < 0.05). As for physiochemical properties, the accumulated ion release (± SD in mg) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 0.011 ± 0.003, 0 and 0 for calcium ion, respectively (Ca-Ag-Zeo > Ag-Zeo, Zeo; p < 0.001), and 0.213 ± 0.032, 0.209 ± 0.019 and 0 for silver ion, respectively (Ca-Ag-Zeo, Ag-Zeo > Zeo; p < 0.001). As for anti-microbial ability, the MBC/MFC (mg/mL) of Ca-Ag-Zeo, Ag-Zeo and Zeo were 32, 16 and > 256 against Streptococcus mutans; 32, 16, > 256 against Lactobacillus acidophilus; 16, 16, and 256 against Lactobacillus casei; 0.25, 0.125; and 2, 1, > 256 against Candida albicans, respectively. CONCLUSION: A novel Ca-Ag-Zeo was developed. It presented better biocompatibility compared to Ag-Zeo. It released calcium and silver ions sustainably, and it could inhibit the growth of common cariogenic microorganisms.

A preliminary investigation into the impact of soft tissue augmentation-based periodontal phenotype modification therapy for patients exhibiting class III decompensation.

BACKGROUND: Patients with skeletal angle Class III malocclusion usually have inadequate hard and soft tissue volume at the mandibular anterior teeth. The labial proclination at the teeth may lead to gingival recession. The purpose of this study was to explore whether periodontal phenotype modification therapy with soft tissue augmentation (PhMT-s) can prevent gingival recession in these patients. METHODS: Four patients with skeletal Class III malocclusion and a thin periodontal phenotype underwent surgical-orthodontic treatment. Prior to tooth movement, they underwent a minimally invasive vestibular incision with subperiosteal tunnel access combined with autogenous connective tissue grafts for periodontal phenotype modification with soft tissue augmentation (PhMT-s). The labial gingival thickness of the anterior mandibular teeth was measured at three distinct levels: at the cementoenamel junction (GT0), 3 mm apical to the CEJ (GT3), and 6 mm apical to the CEJ (GT6). These measurements were taken at baseline, three months following PhMT-s, and after tooth decompensation. Additionally, a biopsy sample was obtained from the PhMT-s site of one patient. All sections were subsequently stained using hematoxylin and eosin, Masson trichrome, Sirius Red, and immunohistochemistry. RESULTS: The thickness of the labial gingiva was increased about 0.42 to 2.00 mm after PhMT-s. At the end of pre-orthognathic surgical orthodontic treatment, the thickness of the labial gingiva was increased about - 0.14 to 1.32 mm compared to the baseline and no gingival recession occurred after the pre-orthognathic surgical orthodontic treatment. The histologic results demonstrated that the grafts obtained from the PhMT-s site exhibited increased deposition of collagen fibers. Moreover, the proportion of type III collagen increased and the grafts displayed significantly reduced positive expression of CD31 and OCN. CONCLUSIONS: PhMT-s increased the thickness of the soft tissue, stabilizing the gingival margin for teeth exhibiting a thin periodontal phenotype and undergoing labial movement. This is attributed to the increased deposition of collagen fibers.

Deep learning based approach: automated gingival inflammation grading model using gingival removal strategy.

Gingival inflammation grade serves as a well-established index in periodontitis. The aim of this study was to develop a deep learning network utilizing a novel feature extraction method for the automatic assessment of gingival inflammation. T-distributed Stochastic Neighbor Embedding (t-SNE) was utilized for dimensionality reduction. A convolutional neural network (CNN) model based on DenseNet was developed for the identification and evaluation of gingival inflammation. To enhance the performance of the deep learning (DL) model, a novel teeth removal algorithm was implemented. Additionally, a Grad-CAM + + encoder was applied to generate heatmaps for computer visual attention analysis. The mean Intersection over Union (MIoU) for the identification of gingivitis was 0.727 ± 0.117. The accuracy rates for the five inflammatory degrees were 77.09%, 77.25%, 74.38%, 73.68% and 79.22%. The Area Under the Receiver Operating Characteristic (AUROC) values were 0.83, 0.80, 0.81, 0.81 and 0.84, respectively. The attention ratio towards gingival tissue increased from 37.73% to 62.20%, and within 8 mm of the gingival margin, it rose from 21.11% to 38.23%. On the gingiva, the overall attention ratio increased from 51.82% to 78.21%. The proposed DL model with novel feature extraction method provides high accuracy and sensitivity for identifying and grading gingival inflammation.

A study on the impact of gargling with compound Scutellaria baicalensis Georgi on oral health and microflora changes in fixed orthodontic patients: An experimental study.

PURPOSE: To investigate the effect of Scutellaria baicalensis Georgi gargle on oral health and changes in oral bacteria among orthodontic patients. METHODS: About 110 cases of oral fixed orthodontic patients were screened from January 2020 to June 2022 at Taizhou Hospital in Zhejiang Province. They were randomly divided into the experimental group (receiving compound S. baicalensis Georgi gargle once a day) and the control group (receiving 0.9% NS gargle once a day), with 55 cases in each group. Gingival samples were collected from both groups before and 3 months after the orthodontic surgery for bacterial culture, and the differences between the 2 groups of patients in Plaque Index (PLI), gingival bleeding index (sBl), and periodontal depth (PD) before and after the operation were compared. Results: The detection levels of PLI, PD, and sBI in the experimental group were lower than those in the control group (P < .05) 3 months after orthodontic surgery (P < .05); after orthodontic correction for 3 months, there was a significant difference in coccus, bacillus, Campylobacter, Clostridium, Helicobacter, and filamentous bacteria between the experimental group and the control group (P < .05); and Porphyromonas gingivalis, Fusobacterium nucleatum, Bacteroides forsythus (B.f), and Agglomerata actinomycetes in the 2 groups were statistically significant after 3 months of orthodontic treatment (P < .05). CONCLUSION SUBSECTIONS: In fixed orthodontic treatment, S. baicalensis Georgi gargle can effectively inhibit oral pathogens and maintain periodontal health.

Metatranscriptomic analysis shows functional alterations in subgingival biofilm in young smokers with periodontitis: a pilot study.

OBJECTIVE: This study aimed to assess the influence of smoking on the subgingival metatranscriptomic profile of young patients affected by stage III/IV and generalized periodontal disease. METHODOLOGY: In total, six young patients, both smokers and non-smokers (n=3/group), who were affected by periodontitis were chosen. The STROBE (Strengthening the Reporting of Observational Studies in Epidemiology) guidelines for case-control reporting were followed. Periodontal clinical measurements and subgingival biofilm samples were collected. RNA was extracted from the biofilm and sequenced via Illumina HiSeq. Differential expression analysis used Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment, and differentially expressed genes were identified using the Sleuth package in R, with a statistical cutoff of ≤0.05. RESULTS: This study found 3351 KEGGs in the subgingival biofilm of both groups. Smoking habits altered the functional behavior of subgingival biofilm, resulting in 304 differentially expressed KEGGs between groups. Moreover, seven pathways were modulated: glycan degradation, galactose metabolism, glycosaminoglycan degradation, oxidative phosphorylation, peptidoglycan biosynthesis, butanoate metabolism, and glycosphingolipid biosynthesis. Smoking also altered antibiotic resistance gene levels in subgingival biofilm by significantly overexpressing genes related to beta-lactamase, permeability, antibiotic efflux pumps, and antibiotic-resistant synthetases. CONCLUSION: Due to the limitations of a small sample size, our data suggest that smoking may influence the functional behavior of subgingival biofilm, modifying pathways that negatively impact the behavior of subgingival biofilm, which may lead to a more virulent community.

Preclinical evaluation of mucogingival defect treatment using piscine membranes: An in vivo assessment of wound healing.

Periodontitis is a bacteria-induced chronic inflammatory disease characterized by degradation of the supporting tissue and bone in the oral cavity. Treatment modalities seek to facilitate periodontal rehabilitation while simultaneously preventing further gingival tissue recession and potentially bone atrophy. The aim of this study was to compare two differently sourced membranes, a resorbable piscine collagen membrane and a porcine-derived collagen membrane, in the repair of soft tissue defects utilizing a preclinical canine model. This in vivo component consisted of 10 beagles which were subjected to bilateral maxillary canine mucogingival flap defects, as well as bilateral soft tissue defects (or pouches) with no periodontal ligament damage in the mandibular canines. Defects received either a piscine-derived dermal membrane, (Kerecis® Oral, Ísafjörður, Iceland) or porcine-derived dermal membrane (Geistlich Mucograft®, Wolhusen, Switzerland) in a randomized fashion (to avoid site bias) and were allowed to heal for 30, 60, or 90 days. Statistical evaluation of tissue thickness was performed using general linear mixed model analysis of variance and least significant difference (LSD) post hoc analyses with fixed factors of time and membrane. Semi-quantitative analysis employed for inflammation assessment was evaluated using a chi-squared test along with a heteroscedastic t-test and values were reported as mean and corresponding 95% confidence intervals. In both the mucogingival flap defects and soft tissue gingival pouches, no appreciable qualitative differences were observed in tissue healing between the membranes. Furthermore, no statistical differences were observed in the thickness measurements between piscine- and porcine-derived membranes in the mucogingival flap defects (1.05 mm [±0.17] and 1.29 mm [±0.17], respectively [p = .06]) or soft tissue pouches (1.36 mm [±0.14] and 1.47 mm [±0.14], respectively [p = .27]), collapsed over time. Independent of membrane source (i.e., piscine or porcine), similar inflammatory responses were observed in both the maxilla and mandible at the three time points (p = .88 and p = .79, respectively). Histologic and histomorphometric evaluation results indicated that both membranes yielded equivalent tissue responses, remodeling dynamics and healing patterns for the mucogingival flap as well as the soft tissue gingival pouch defect models.

RNAseq of Gingival Fibroblasts Exposed to PRF Membrane Lysates and PRF Serum.

Platelet-rich fibrin (PRF) is prepared by spontaneous coagulation of fractionated blood. When squeezed between two plates, PRF is separated into solid PRF membranes and a liquid exudate, the PRF serum. The question arises regarding how much the overall activity remains in the PRF membranes and what is discarded into the PRF serum. To this end, we have exposed gingival fibroblasts to lysates prepared from PRF membranes and PRF serum, followed by bulk RNA sequencing. A total of 268 up- and 136 down-regulated genes in gingival fibroblasts exposed to PRF membrane lysates were significantly regulated under the premise of a minimum log2 with 2.5-fold change and a minus log10 significance level of two, respectively. PRF serum only caused 62 up- and 32 down-regulated genes under these conditions. Among the 46 commonly up-regulated genes were CXCL1, CXCL5, CXCL6, CXCL8, IL33, IL6, and PTGS2/COX2, stanniocalcin-1-all linked to an inflammatory response. PRF membrane lysates further increased chemokines CCL2, CCL7, CXCL2, CXCL3, and IL1R1, IL1RL1, and IL1RN, as well as the paracrine factors IL11, LIF, IGF1, BMP2, BMP6, FGF2, and CCN2/CTGF, and all hyaluronan synthases. On the other hand, PRF serum increased DKK1. The genes commonly down-regulated by PRF membrane lysates and PRF serum included interferon-induced protein with tetratricopeptide repeats (IFIT1, IFIT2, IFIT3) and odd-skipped-related transcription factors (OSR1 and OSR2), as well as FGF18 and GDF15, respectively. Taken together, PRF membrane lysates, compared to PRF serum, cause a more complex response in gingival fibroblasts, but each increased chemokine expression in gingival fibroblasts.

Marginal Gingival Thickness Assessment in Three- To Six-Year-Old Preschool Children.

Purpose: Although gingival thickness has been extensively studied in permanent dentition, the literature regarding marginal gingival thickness in primary dentition is insufficient. The purpose of this study was to assess the variations in marginal gingival thickness in preschool-age children. Methods: A cross-sectional study of 4,109 primary teeth was conducted. Using a reamer, the transgingival probing method was employed to assess marginal gingival thickness in healthy preschoolers. Inter-examiner and intra-examiner reproducibility were assessed via the intraclass correlation coefficient. Results: Descriptive statistics revealed that primary maxillary left second molars had the highest mean marginal gingival thickness (1.06 mm), whereas primary mandibular right central incisors had the lowest mean marginal gingival thickness (0.74 mm). Gender-based independent sample t-tests revealed significant differences in the values of primary maxillary right canines (females had greater values than males; P=0.03) and primary mandibular right first molars (males had greater values than females; P=0.01). An inter-arch comparison revealed significant differences between the primary second molars (maxillary more than mandibular; P=0.001). Conclusions: This study reports the first documented marginal gingival thicknesses of primary dentition. It reveals substantial variations in the values of primary maxillary right canines and primary mandibular right first molars and between primary maxillary and mandibular second molars.