Micro-needling versus acellular dermal matrix in RT1 gingival recession coverage: A randomized clinical trial.

AIMS: This randomized trial assessed for the first time the efficacy of coronally advanced flap (CAF) followed by micro-needling (MN) in contrast to CAF with acellular dermal matrix (ADM) on gingival thickness (GT, primary outcome), keratinized tissue width (KTW), clinical attachment level (CAL), probing depth (PD), recession depth (RD), recession width (RW), recession reduction (Rec-Red), complete root coverage (CRC) and percentage of root coverage (all secondary outcomes) in management of RT1 gingival recession in patients with thin gingival phenotype. METHODS: A total of 24 patients (n = 24) with a thin gingival phenotype and single RT1 gingival recession in the aesthetic zone were randomly allocated to test- (CAF + MN; n = 12) or control group (CAF + ADM; n = 12). All clinical parameters were evaluated at baseline, 3 and 6 months. RESULTS: Both groups independently demonstrated significant gain in GT, RW, RD, CAL, PD, Rec-Red, CRC and percentage of root coverage, with reduced PI and BOP (p < .05) at 3 and 6 months, without intergroup differences (p > .05). At 6 months, KTW gain was significantly higher in CAF + MN (5.08 ± 0.9 mm) than in CAF + ADM-group (4.25 ± 1.06 mm; p < .05). Stepwise linear regression model with GT as dependent variable showed that base-line GT was the only statistically significant predictor for GT with a direct correlation between base-line GT and GT after 6 months. CONCLUSION: CAF followed by MN could represent a promising graft-less approach for increasing gingival thickness, comparable to CAF with ADM, with superior keratinized tissue width improvement, in the treatment of RT1 recession defects in patients with thin gingival phenotype.

Effects of oxidized LDL versus IL-1ß/TNF-ɑ/INFÉ£ on human gingival mesenchymal stem cells properties.

AIMS: Oxidized low-density lipoprotein (oxLDL) is an important player in the course of metabolic inflammatory diseases. oxLDL was identified in the gingival crevicular fluid, denoting possible associations between oxLDL-induced inflammation and periodontal disease. The current investigation compared for the first-time direct effects of oxLDL to a cytokine cocktail of IL-1ß/TNF-ɑ/INF-γ on gingival mesenchymal stem cells' (G-MSCs) attributes. METHODS: Human third passage G-MSCs, isolated from connective tissue biopsies (n = 5) and characterized, were stimulated in three groups over 7 days: control group, cytokine group (IL-1ß[1 ng/mL], TNF-α[10 ng/mL], IFN-γ[100 ng/mL]), or oxLDL group (oxLDL [50 µg/mL]). Next Generation Sequencing and KEGG pathway enrichment analysis, stemness gene expression (NANOG/SOX2/OCT4A), cellular proliferation, colony-formation, multilinear potential, and altered intracellular pathways were investigated via histochemistry, next-generation sequencing, and RT-qPCR. RESULTS: G-MSCs exhibited all mesenchymal stem cells' characteristics. oxLDL group and cytokine group displayed no disparities in their stemness markers (p > .05). Next-generation-sequencing revealed altered expression of the TXNIP gene in response to oxLDL treatment compared with controls (p = .04). Following an initial boosting for up to 5 days by inflammatory stimuli, over 14 day, cellular counts [median count ×10-5 (Q25/Q75)] were utmost in control - [2.6607 (2.0804/4.5357)], followed by cytokine - [0.0433 (0.0026/1.4215)] and significantly lowered in the oxLDL group [0.0274 (0.0023/0.7290); p = .0047]. Osteogenic differentiation [median relative Ca2+ content(Q25/Q75)] was significantly lower in cytokine - [0.0066 (0.0052/0.0105)] compared to oxLDL - [0.0144 (0.0108/0.0216)] (p = .0133), with no differences notable for chondrogenic and adipogenic differentiation (p > .05). CONCLUSIONS: Within the current investigation's limitations, in contrast to cytokine-mediated inflammation, G-MSCs appear to be minimally responsive to oxLDL-mediated metabolic inflammation, with little negative effect on their differentiation attributes and significantly reduced cellular proliferation.

Evaluation of the remineralization potential of self-assembling peptide P11-4 with fluoride compared to fluoride varnish in the management of incipient carious lesions: a randomized controlled clinical trial.

OBJECTIVES: The present trial's aim was to compare the remineralization potential of self-assembling peptide P11-4 combined with fluoride to that of fluoride varnish. MATERIALS AND METHODS: Twenty-eight participants with 58 incipient carious lesions were enrolled in the present trial. Participants were randomly divided into two groups with 14 participants and 29 incipient lesions in each group. Patients were assigned either to self-assembling peptide combined with fluoride (Curodont Repair Fluoride Plus™) or sodium fluoride varnish (NaF, Bifluorid 10) groups. Both agents were applied according to the manufacturer's instructions on non-cavitated incipient carious lesions. Lesions were assessed by two calibrated and blinded assessors at baseline, and after one-, three- and six-months using a laser fluorescence device (DIAGNOdent). RESULTS: Although laser fluorescence scores significantly improved in both groups over time (p < 0.05), no notable differences were evident between both groups at one-month (p > 0.05). Yet, at three- and six-months statistically lower laser fluorescence readings were evident in the self-assembling peptide combined with fluoride group in comparison to the fluoride alone group (p < 0.05). There was 60% less risk for caries progression for Curodont Repair Fluoride Plus™ when compared to NaF varnish after six months. Self-assembling peptide combined with fluoride was able to change 65.5% of non-cavitated carious lesions from DIAGNOdent score 3 (11-20) to score 1 (0-4). Fluoride varnish was able to change 13.8% of the lesions from score 3 to score 1 after six months. CONCLUSIONS: The self-assembling peptide combined with fluoride varnish showed higher remineralization potential than fluoride varnish alone for incipient carious lesions over a six-months follow up. CLINICAL RELEVANCE: The combination of self-assembling peptide P11-4 and fluoride could offer a new tool in managing incipient carious lesions.

Evaluation of minimally invasive esthetic crown lengthening using an open flap versus flapless surgical approach: A randomized controlled clinical trial.

OBJECTIVES: Esthetic crown lengthening (ECL) is commonly advocated to treat patients with altered passive eruption (APE). Since the introduction of the minimally invasive surgical concept, a limited number of studies have investigated this technique in a standardized manner, with further studies required to verify the validity and predictability of the minimally invasive FL-technique. The current randomized trial compares a minimally invasive (ECL), using piezosurgery with flapless-approach (FL), versus an open-flap (OF) approach in the management of patients with APE Type 1B. MATERIALS AND METHODS: Twenty-four patients diagnosed with APE Type 1B were randomly assigned into test (FL) with tunneling approach or control (OF) group with minimally invasive flap reflection (n = 12/group). Postoperative pain was assessed during the first 48 h. Gingival margin (GM) level relative to a custom-made stent (rGM) and patient satisfaction were assessed preoperative, immediately after surgery, at 3 and 6 months postsurgically. Postoperative swelling was reported for the first week postsurgically. Plaque index (PI), bleeding on probing (BoP), clinical attachment level (CAL), pocket depth (PD) and pink esthetic score (PES), were evaluated at baseline and 6 months. Linear regression analysis was conducted for pain. RESULTS: OF-group reported significantly higher pain and swelling scores than FL-group during the first 48 h (p < 0.05). FL-group showed no significant differences regarding rGM between 3 and 6 months, in contrast to OF-group, where a significant decrease in rGM was notable (p < 0.05). No significant differences in PI, BoP, CAL, PD, PES, and patient satisfaction scores were evident between groups (p > 0.05). Regression analysis demonstrated that treatment and gender were significant predictors for pain (p < 0.05). CONCLUSIONS: Within the current study's limitations, piezo-surgical ECL with FL-approach presented significantly lower postoperative pain, swelling, and early GM stability compared to OF-approach. CLINICAL SIGNIFICANCE: Piezosurgical ECL with a FL-approach can be considered a predictable technique with advantages over the OF-approach in the management of patients with APE Type1B.

Can vitamins improve periodontal wound healing/regeneration?

Periodontitis is a complex inflammatory disorder of the tooth supporting structures, associated with microbial dysbiosis, and linked to a number if systemic conditions. Untreated it can result in an irreversible damage to the periodontal structures and eventually teeth loss. Regeneration of the lost periodontium requires an orchestration of a number of biological events on cellular and molecular level. In this context, a set of vitamins have been advocated, relying their beneficial physiological effects, to endorse the biological regenerative events of the periodontium on cellular and molecular levels. The aim of the present article is to elaborate on the question whether or not vitamins improve wound healing/regeneration, summarizing the current evidence from in vitro, animal and clinical studies, thereby shedding light on the knowledge gap in this field and highlighting future research needs. Although the present review demonstrates the current heterogeneity in the available evidence and knowledge gaps, findings suggest that vitamins, especially A, B, E, and CoQ10 , as well as vitamin combinations, could exert positive attributes on the periodontal outcomes in adjunct to surgical or nonsurgical periodontal therapy.

Injectable platelet-rich fibrin with demineralized freeze-dried bone allograft compared to demineralized freeze-dried bone allograft in intrabony defects of patients with stage-III periodontitis: a randomized controlled clinical trial.

AIM: The current randomized controlled clinical trial assessed the effect of injectable platelet-rich fibrin (I-PRF) combined with demineralized freeze-dried bone allograft (DFDBA) compared to DFDBA alone in the management of intrabony defects of stage-III periodontitis patients. METHODOLOGY: Following sample size calculation, twenty stage-III periodontitis patients with ≥ 5 mm clinical attachment level (CAL)-loss and ≥ 3 mm intrabony defects were randomized into test (I-PRF + DFDBA; n = 10) and control (DFDBA; n = 10) groups. CAL (primary outcome), periodontal probing depth (PPD), gingival recession depth (GRD), full-mouth plaque scores (FMPS), full-mouth bleeding scores (FMBS), radiographic linear defect depth (RLDD), and bone fill (secondary outcomes) were examined at baseline, 3, 6, and 9 months post-surgically. RESULTS: I-PRF + DFDBA and DFDBA independently demonstrated significant intragroup CAL-gain, PPD-, and RLDD-reduction at 3, 6, and 9 months (p < 0.05), with no significant intergroup differences observed (p > 0.05). CAL-gain (mean ± SD) of 2.40 ± 0.70 mm and 2.50 ± 0.85 mm and PPD-reduction of 3.50 ± 1.18 mm and 2.80 ± 0.42 mm were demonstrated for I-PRF + DFDBA and DFDBA at 9 months respectively. Both groups showed significant intragroup RLDD improvement, with a RLDD of 3.58 ± 0.66 mm and 3.89 ± 1.57 mm for I-PRF + DFDBA and DFDBA at 9 months respectively. Stepwise linear regression analysis revealed that baseline RLDD and bone fill at 9 months were significant predictors of CAL (p < 0.05). CONCLUSION: Within the present study's limitations, DFDBA with or without I-PRF resulted in significant improvement in clinical and radiographic periodontal parameters in the surgical treatment of periodontal intrabony defects of stage-III periodontitis patients. Addition of I-PRF to DFDBA does not appear to significantly enhance the DFDBA's reparative/regenerative outcomes. CLINICAL RELEVANCE: Within the current study's limitations, routinely adding I-PRF to DFDBA cannot be recommended to significantly improve DFDBA's treatment outcomes in intrabony defects.

Molecular Basis beyond Interrelated Bone Resorption/Regeneration in Periodontal Diseases: A Concise Review.

Periodontitis is the sixth most common chronic inflammatory disease, destroying the tissues supporting the teeth. There are three distinct stages in periodontitis: infection, inflammation, and tissue destruction, where each stage has its own characteristics and hence its line of treatment. Illuminating the underlying mechanisms of alveolar bone loss is vital in the treatment of periodontitis to allow for subsequent reconstruction of the periodontium. Bone cells, including osteoclasts, osteoblasts, and bone marrow stromal cells, classically were thought to control bone destruction in periodontitis. Lately, osteocytes were found to assist in inflammation-related bone remodeling besides being able to initiate physiological bone remodeling. Furthermore, mesenchymal stem cells (MSCs) either transplanted or homed exhibit highly immunosuppressive properties, such as preventing monocytes/hematopoietic precursor differentiation and downregulating excessive release of inflammatory cytokines. In the early stages of bone regeneration, an acute inflammatory response is critical for the recruitment of MSCs, controlling their migration, and their differentiation. Later during bone remodeling, the interaction and balance between proinflammatory and anti-inflammatory cytokines could regulate MSC properties, resulting in either bone formation or bone resorption. This narrative review elaborates on the important interactions between inflammatory stimuli during periodontal diseases, bone cells, MSCs, and subsequent bone regeneration or bone resorption. Understanding these concepts will open up new possibilities for promoting bone regeneration and hindering bone loss caused by periodontal diseases.

Toll-like receptor expression profile of stem/progenitor cells from human exfoliated deciduous teeth.

BACKGROUND: Stem/progenitor cells from human exfoliated deciduous teeth (SHED) show remarkable pluripotent, regenerative, and immunological capacities. During in vivo regenerative processes, there could be the presence of SHED in the surrounding inflammatory microenvironment, through toll-like receptors (TLRs). AIM: The aim of this paper was to present a characteristic TLR expression profile on SHED for the first time. DESIGN: Cells were harvested from extracted primary teeth (n = 10), anti-STRO-1 immunomagnetically sorted and cultivated, through colony-forming units (CFUs). SHED were examined for mesenchymal stem/progenitor cell traits, including the expression of clusters of differentiation (CDs) 14, 34, 45, 73, 90, 105, and 146, and their multilineage differentiation aptitude. TLRs 1-10 expression was investigated for SHED in uninflamed and inflamed (25 ng/mL IL-1ß, 103 U/mL IFN-γ, 50 ng/mL TNF-α, and 3 × 103 U/mL IFN-α; SHED-i) microenvironmental conditions. RESULTS: SHED were negative for CDs 14, 34, and 45, but were positive for CDs 73, 90, 105, and 146, and demonstrated characteristic multilineage differentiation. In an uninflamed microenvironment, SHED expressed TLRs 1, 2, 3, 4, 6, 8, 9, and 10. The inflammatory microenvironment downregulated TLR7 significantly on gene level and upregulated TLR8 on gene and protein levels (p < .05; Wilcoxon signed-rank test). CONCLUSION: There appears to be a unique TLR expression profile on SHED, which could modulate their immunological and regenerative abilities in oral tissue engineering approaches.

In vitro evaluation of the effect of the electronic cigarette aerosol, Cannabis smoke, and conventional cigarette smoke on the properties of gingival fibroblasts/gingival mesenchymal stem cells.

OBJECTIVE: The current study aimed to evaluate the effect of electronic cigarette (EC) aerosol, Cannabis, and conventional cigarettes smoke on gingival fibroblast/gingival mesenchymal stem cells' (GF/G-MSCs) of never smokers. MATERIAL AND METHODS: Human GF/G-MSCs (n = 32) were isolated and characterized using light microscopy, flow cytometry, and multilineage differentiation ability. Following the application of aerosol/smoke extracts, GF/G-MSCs were evaluated for cellular proliferation; colony-forming units (CFU-F) ability; cellular viability (using the MTT assay); mitochondrial depolarization using JC-1 dye; and genes' expression of ATM, p21, Oct4, and Nanog. RESULTS: Colony-forming units and viability (OD 450 nm) were significantly reduced upon exposure to Cannabis (mean ± SD; 5.5 ± 1.5; p < .00001, 0.47 ± 0.21; p < .05) and cigarettes smoke (2.3 ± 1.2 p < .00001, 0.59 ± 0.13, p < .05), while EC aerosol showed no significant reduction (10.8 ± 2.5; p = .05, 1.27 ± 0.47; p > .05) compared to the control group (14.3 ± 3, 1.33 ± 0.12). Significantly upregulated expression of ATM, Oct4, and Nanog (gene copies/GADPH) was noticed with Cannabis (1.5 ± 0.42, 0.82 ± 0.44, and 1.54 ± 0.52, respectively) and cigarettes smoke (1.52 ± 0.75, 0.7 ± 0.14, and 1.48 ± 0.79, respectively; p < .05), whereas EC aerosol caused no statistically significant upregulation of these genes compared to the control group (0.63 ± 0.1, 0.31 ± 0.12, and 0.64 ± 0.46, respectively; p > .05). The p21 gene was not significantly downregulated in EC aerosol (1.22 ± 0.46), Cannabis (0.71 ± 0.24), and cigarettes smokes (0.83 ± 0.54) compared to the control group (p = .053, analysis of variance). CONCLUSION: Cannabis and cigarettes smoke induce DNA damage and cellular dedifferentiation and negatively affect the cellular proliferation and viability of GF/G-MSCs of never smokers, whereas EC aerosol showed a significantly lower impact on these properties.

Clinical and radiographic evaluation of low-speed platelet-rich fibrin (PRF) for the treatment of intra-osseous defects of stage-III periodontitis patients: a randomized controlled clinical trial.

AIM: The current randomized controlled trial assessed for the first time the effect of a low-speed platelet-rich fibrin (PRF) with open flap debridement (OFD) versus OFD alone in the treatment of periodontal intra-osseous defects of stage-III periodontitis patients. METHODS: Twenty-two periodontitis patients with ≥ 6 mm probing depth (PD) and ≥ 3 mm intra-osseous defects were randomized into test (PRF + OFD; n = 11) and control (OFD; n = 11) groups. Clinical attachment level (CAL)-gain (primary outcome), PD-reduction, gingival recession depth (GRD), full-mouth bleeding scores (FMBS), full-mouth plaque scores (FMPS), radiographic linear defect depth (RLDD), and radiographic bone fill (secondary-outcomes) were examined over 9 months post-surgically. RESULTS: Low-speed PRF + OFD and OFD demonstrated significant intra-group CAL-gain and PD- and RLDD-reduction at 3, 6, and 9 months (p < 0.01). Low-speed PRF + OFD exhibited a significant CAL-gain of 3.36 ± 1.12 mm at 6 months (2.36 ± 0.81 mm for the control group; p < 0.05), and a significantly greater PD-reduction of 3.36 ± 1.12 mm at 3 months, of 3.64 ± 1.12 mm at 6 months and of 3.73 ± 1.19 mm at 9 months (2.00 ± 0.89 mm, 2.09 ± 1.04 mm, and 2.18 ± 1.17 mm in the control group respectively; p < 0.05). No significant differences were notable regarding GRD, FMPS, FMBS, RLDD, or bone fill between both groups (p > 0.05). CONCLUSIONS: Within the current clinical trial's limitations, the use of low-speed PRF in conjunction with OFD improved CAL and PD post-surgically, and could provide a cost-effective modality to augment surgical periodontal therapy of intra-osseous defects of stage-III periodontitis patients. CLINICAL RELEVANCE: Low-speed PRF could provide a cost-effective modality to improve clinical attachment gain and periodontal probing depth reduction with open flap debridement approaches.

Alveolar ridge preservation using autogenous whole-tooth versus demineralized dentin grafts: A randomized controlled clinical trial.

OBJECTIVE: The objective of this randomized controlled trial was to evaluate the radiographic changes and histologic healing following alveolar ridge preservation (ARP) using autogenous whole tooth (AWTG), test group, versus autogenous demineralized dentin graft (ADDG), control group. MATERIAL AND METHODS: Twenty non-molar teeth indicated for extraction were randomized into two groups (n = 10/group). Extracted teeth were prepared into AWTG or ADDG (0.6N HCl; 30 min), inserted into extraction sockets and covered by collagen membranes. Cone-beam computed tomography (CBCT) scans at baseline and six months were compared to assess ridge-dimensional changes. At six months, bone biopsies of engrafted sites were harvested and analyzed histomorphometrically. RESULTS: All sites healed uneventfully. Reduction was 0.85 ± 0.38 mm and 1.02 ± 0.45 mm in ridge width, 0.61 ± 0.20 mm and 0.72 ± 0.27 mm in buccal and 0.66 ± 0.31 mm and 0.56 ± 0.24 mm in lingual ridge height for the AWTG and ADDG group, respectively (p > .05). Histologically, no inflammatory reactions were noticeable and all samples showed new bone formation. Qualitatively, graft-bone amalgamations were more pronounced in ADDG samples. Histomorphometrically, new bone, graft remnants and soft tissue occupied 37.55% ± 8.94%, 17.05% ± 5.58% and 45.4% ± 4.06% of the areas in the AWTG group and 48.4% ± 11.56%, 11.45% ± 4.13% and 40.15% ± 7.73% in the ADDG group of the examined areas, respectively (p > .05). CONCLUSIONS: AWTG and ADDG are similarly effective in ARP. Yet, histologically ADDG seems to demonstrate better graft remodeling, integration and osteoinductive properties.

Effect of locally delivered adjunctive antibiotics during surgical periodontal therapy: a systematic review and meta-analysis.

AIM: The present study aimed to systematically assess current evidence on effects of locally delivered antibiotics during periodontal surgery compared to periodontal surgery alone on clinical attachment level (CAL) gain, probing pocket depth (PPD) reduction, recession depth (RD) changes, gingival index (GI), bleeding on probing (BOP), and plaque index (PI). METHODOLOGY: MEDLINE-PubMed, Cochrane-CENTRAL and Scopus databases were searched up to April 2021 for randomized clinical trials (RCT), evaluating effects of locally delivered antibiotics during periodontal surgery. CAL gain served as primary, while PPD reduction, RD changes, GI and PI as secondary outcomes. The Cochrane Risk of Bias Tool was used to assess possible bias. Data were extracted, and meta-analysis was performed where appropriate. RESULT: Screening of 2314 papers resulted in nine eligible studies. No adverse events were reported. Data on outcome variables were pooled and analyzed using generic inverse variance model and presented as weighted mean difference (WMD) and 95% confidence interval (95% CI). Statistically significant improvements in favor of antibiotics' delivery were observed in studies with follow-up of ≤6 months for CAL gain (WMD = 0.61 mm (95% CI [0.07, 1.14]; p = 0.03), PPD reduction (WMD = 0.41 mm (95% CI [0.02, 0.80]; p = 0.04)) and BOP (WMD = -28.47% (95% CI [-33.00, -23.94]); p < 0.001), while for GI improvements were notable for >6 to 12 months (WMD = -0.27 (95% CI [-0.49, -0.06]; p = 0.01)). CONCLUSION: Within the current review's limitations, locally delivered antibiotics during surgical periodontal therapy results in post-surgical improvements for CAL, PPD, and BOP (≤6 months) with a longer-lasting GI improvement. Further randomized controlled trials are needed with true periodontal end-points to assess the ideal antibiotic agent, dosage, and delivery methods. CLINICAL RELEVANCE: Local delivery of antibiotics during periodontal surgery improved clinical parameters for up to 6-month follow-up, with beneficial longer effects on gingival inflammation. Within the current study's limitation, the presented evidence could support the elective usage of locally delivered antibiotics during surgical periodontal therapy.

Clinical and radiographic effects of ascorbic acid-augmented platelet-rich fibrin versus platelet-rich fibrin alone in intra-osseous defects of stage-III periodontitis patients: a randomized controlled clinical trial.

AIM: To assess platelet-rich fibrin (PRF) with ascorbic acid (AA) versus PRF in intra-osseous defects of stage-III periodontitis patients. METHODOLOGY: Twenty stage-III/grade C periodontitis patients, with ≥ 3 mm intra-osseous defects, were randomized into test (open flap debridement (OFD)+AA/PRF; n = 10) and control (OFD+PRF; n = 10). Clinical attachment level (CAL; primary outcome), probing pocket depth (PPD), gingival recession depth (RD), full-mouth bleeding scores (FMBS), full-mouth plaque scores (FMPS), radiographic linear defect depth (RLDD) and radiographic defect bone density (RDBD) (secondary-outcomes) were examined at baseline, 3 and 6 months post-surgically. RESULTS: OFD+AA/PRF and OFD+PRF demonstrated significant intragroup CAL gain and PPD reduction at 3 and 6 months (p < 0.001). OFD+AA/PRF and OFD+PRF showed no differences regarding FMBS or FMPS (p > 0.05). OFD+AA/PRF demonstrated significant RD reduction of 0.90 ± 0.50 mm and 0.80 ± 0.71 mm at 3 and 6 months, while OFD+PRF showed RD reduction of 0.10 ± 0.77 mm at 3 months, with an RD-increase of 0.20 ± 0.82 mm at 6 months (p < 0.05). OFD+AA/PRF and OFD+PRF demonstrated significant RLDD reduction (2.29 ± 0.61 mm and 1.63 ± 0.46 mm; p < 0.05) and RDBD-increase (14.61 ± 5.39% and 12.58 ± 5.03%; p > 0.05). Stepwise linear regression analysis showed that baseline RLDD and FMBS at 6 months were significant predictors of CAL reduction (p < 0.001). CONCLUSIONS: OFD+PRF with/without AA significantly improved periodontal parameters 6 months post-surgically. Augmenting PRF with AA additionally enhanced gingival tissue gain and radiographic defect fill. CLINICAL RELEVANCE: PRF, with or without AA, could significantly improve periodontal parameters. Supplementing PRF with AA could additionally augment radiographic linear defect fill and reduce gingival recession depth.

TLR3 ligation affects differentiation and stemness properties of gingival mesenchymal stem/progenitor cells.

AIM: Toll-like receptors are key players in mesenchymal stem/progenitor cells' micro-environmental crosstalk, endorsing various biological reactions. For the first time, this study investigates the effects of TLR3-ligation on gingival mesenchymal stem/progenitor cells (G-MSCs) stemness and differentiation properties. MATERIAL AND METHODS: G-MSCs (n = 5) were isolated, sorted using anti-STRO-1 antibodies,and sowed on culture dishes to generate colony-forming units (CFUs), and their stem/progenitor cells' features and TLR3 expression were characterized. Subsequently, TLR3 activation of G-MSCs via Poly (I:C) was done, followed by an analysis of the expression of pluripotency-related factors, mesenchymal stemness-associated surface markers, and the ability to form CFUs and multilineage differentiation, using qualitative and quantitative histochemistry and RT-PCR. RESULTS: G-MSCs demonstrated all predefined stem/progenitor cells' characteristics and TLR3 expression. TLR3-activated G-MSCs showed a significantly reduced ability to form CFUs and pluripotency transcriptional factors expression. Mesenchymal stem/progenitor cell-associated surface markers and multilinear differentiation potential were significantly higher following TLR3 ligation (p < .05, Wilcoxon signed rank test). CONCLUSIONS: TLR3-mediated activation maintains the mesenchymal stem/progenitor cells phenotype and drives G-MSCs' differentiation and commitment, with a shift away from an undifferentiated pluripotent cellular phenotype. This distinctive modulation could influence potential therapeutic applications of G-MSCs.

Alvogyl and absorbable gelatin sponge as palatal wound dressings following epithelialized free gingival graft harvest: a randomized clinical trial.

OBJECTIVES: This randomized controlled trial compares for the first time effects of Alvogyl versus absorbable gelatin sponge as palatal wound dressings on postoperative pain, amount of analgesic consumption, post-surgical bleeding, and wound re-epithelization. MATERIALS AND METHODS: Following sample size calculation, 36 systemically healthy patients requiring palatal mucosal graft harvesting were randomized to receive Alvogyl (intervention group, 18 patients) or absorbable gelatin sponge (control group, 18 patients) palatal dressings. Patient-reported VAS pain scores over 2 weeks were defined as primary outcome. Post-surgical bleeding, number of analgesics consumed, and complete re-epithelialization of the palatal wound for up to 5 weeks were defined as secondary outcomes. RESULTS: Although significantly higher VAS pain scores were reported in the control as compared with the intervention group up to 12 days post-surgically (from (median [range]) 8.5 [2-10] to 1 [0-2] and from 6 [0-10] to 0 [0-2] respectively), with higher analgesics consumption (from 2 [1-3] to 1 [0-3] and from 1 [0-3] to 0 [0-2] tablets respectively), a multivariate regression analysis considering age, gender, graft width/length, tissue thickness, analgesics intake, and dressing type demonstrated no statistically significant effect of any factor, including dressing type on VAS pain scores. At 4 weeks, 22.2% of patients in the intervention group versus 11.1% in the control group demonstrated complete re-epithelization of their palatal engraftment site, before complete re-epithelization in both groups at 5 weeks. No post-surgical bleeding was reported with both dressings. CONCLUSIONS: Within the study's limitations, results suggest Alvogyl as a practical palatal surgical dressing, comparable with absorbable gelatin sponge in cost, pain reduction, hemostasis, and re-epithelization properties. TRIAL REGISTRATION: www.ClinicalTrials.gov Identifier: NCT03402321 CLINICAL RELEVANCE: Alvogyl could present a novel palatal wound dressing material, comparable with gelatin sponge.

Retinol/inflammation affect stemness and differentiation potential of gingival stem/progenitor cells via Wnt/ß-catenin.

BACKGROUND AND OBJECTIVE: Inflammatory cytokines impact the course of periodontal disease, repair, and regeneration. Vitamin A and its metabolites are inflammation-modulatory biomolecules, affecting cellular pluripotency. The aim of this study was to investigate the effect of retinol and periodontal inflammatory cytokines (IL-1ß/TNF-α/IFN-γ) on pluripotency and proliferative properties of gingival mesenchymal stem/progenitor cells (G-MSCs), for the first time. MATERIAL AND METHODS: Human G-MSCs (n = 5) were STRO-1 immuno-magnetically sorted, characterized and expanded in basic medium (control group), in basic medium with IL-1ß (1 ng/mL), TNF-α (10 ng/mL), and IFN-γ (100 ng/mL) (inflammatory group), in basic medium with retinol (20 µmol/L) (retinol group) and with retinol added to the inflammatory group (inflammatory/retinol group). ß-catenin levels at 1 hour, cellular proliferation over 14 days, and colony-forming units (CFUs) at 14 days were investigated. Pluripotency gene expressions were examined at 1, 3, and 5 days via reverse transcription-polymerase chain reaction (RT-PCR). Multilineage differentiation potential was evaluated, following 5 days priming, using qualitative and quantitative histochemistry and RT-PCR. RESULTS: G-MSCs were CD14- , CD34- , CD45- , CD73+ , CD90+ , CD105+ , and showed mesenchymal stem/progenitor cells' hallmarks, CFUs, and multilineage differentiation potential. Intracellular ß-catenin significantly declined in the stimulated groups (P < 0.001, Friedman test). Cellular proliferation at 72 hours was most prominent in the control and inflammatory group [Median cell numbers (Q25/Q75); 6806 (4983/7312) and 5414 (4457/7230), respectively], followed by an upsurge in the retinol group. At 14 days, the retinol group exhibited the highest CFUs [Median CFUs (Q25/Q75); 35 (20/58), P = 0.043, Wilcoxon signed-rank]. Nanog was most expressed in the inflammatory and retinol group [Median gene expression/PGK1 (Q25/Q75); 0.0006 (0.0002/0.0014) and 0.0005 (0.0003/0.0008)]. Inflammation significantly upregulated Sox2 expression [0.0002 (0.0008/0.0005)], while its expression was diminished in the retinol and inflammatory/retinol group (P < 0.001, Friedman test). Inflammatory/retinol group exhibited the highest multilineage differentiation potential. CONCLUSION: Controlled short-term inflammatory/retinol stimuli activate the Wnt/ß-catenin pathway, affecting G-MSCs' pluripotency, proliferation, and differentiation. The present findings provide further insights into the inflammatory-regenerative interactions and their modulation potential for G-MSCs-mediated periodontal repair/regeneration.

The periodontal stem/progenitor cell inflammatory-regenerative cross talk: A new perspective.

Adult multipotent stem/progenitor cells, with remarkable regenerative potential, have been isolated from various components of the human periodontium. These multipotent stem/progenitor cells include the periodontal ligament stem/progenitor cells (PDLSCs), stem cells from the apical papilla (SCAP), the gingival mesenchymal stem/progenitor cells (G-MSCs), and the alveolar bone proper stem/progenitor cells (AB-MSCs). Whereas inflammation is regarded as the reason for tissue damage, it also remains a fundamental step of any early healing process. In performing their periodontal tissue regenerative/reparative activity, periodontal stem/progenitor cells interact with their surrounding inflammatory micro-environmental, through their expressed receptors, which could influence their fate and the outcome of any periodontal stem/progenitor cell-mediated reparative/regenerative activity. The present review discusses the current understanding about the interaction of periodontal stem/progenitor cells with their surrounding inflammatory micro-environment, elaborates on the inflammatory factors influencing their stemness, proliferation, migration/homing, differentiation, and immunomodulatory attributes, the possible underlying intracellular mechanisms, as well as their proposed relationship to the canonical and noncanonical Wnt pathways.

Predictors for tooth loss in periodontitis patients: Systematic review and meta-analysis.

AIM: A range of predictors for tooth loss in periodontitis patients have been reported. We performed a systematic review and meta-analysis to assess the consistency and magnitude of any association between a total of 12 predictors and tooth loss. MATERIALS AND METHODS: Medline/Embase/Central were searched for longitudinal studies investigating the association between predictors and tooth loss in periodontitis patients. Random-effects meta-analysis was performed, and study quality assessed. RESULTS: Twenty studies (15,422 patients, mean follow-up: 12 years) were included. The mean annual tooth loss/patient was 0.12 (min./max: 0.01/0.36). Older patients (n = 8 studies; OR: 1.05, 95% CI: 1.03-1.08/year), non-compliant ones (n = 11; 1.51, 1.06-2.16), diabetics (n = 7; 1.80, 1.26-2.57), those with IL-1-polymorphism (n = 3; 1.80; 1.29-2.52) and smokers (n = 15; 1.98, 1.58-2.48) had a significantly higher risk of tooth loss. Teeth with bone loss (n = 3; 1.04, 1.03-1.05/%), high probing pocket depth (n = 6; 3.19, 1.70-5.98), mobility (n = 4; 3.71, 1.65-8.38) and molars (n = 4; 4.22, 2.12-8.39), especially with furcation involvement (n = 5; 2.68, 1.75-4.08) also showed higher risks. Gender (n = 16; 0.95, 0.86-1.05) and endodontic affection (n = 3; 3.62, 0.99-13.2) were not significantly associated with tooth loss. CONCLUSIONS: Older, non-compliant, smoking or diabetic patients, and teeth with bone loss, high probing pocket depth, mobility, or molars, especially with furcation involvement showed higher risks of tooth loss.

Secreted frizzled-related protein 5 serum levels in human periodontitis-A nested case-control study.

AIM: Recombinant secreted frizzled-related protein 5 (sFRP5) improved periodontal status in mice. Thus, this study aimed to investigate this finding in human periodontitis using an epidemiological approach. MATERIALS AND METHODS: sFRP5 and wnt5a concentrations were determined in human serum from the Food Chain Plus cohort using ELISAs. A total of 128 patients with periodontitis and tooth loss and 245 patients with periodontitis without tooth loss were compared to 373 sex-, smoker-, age- and BMI-matched individuals in a nested case-control design. RESULTS: Systemic sFRP5 serum levels were significantly lower in patients with periodontitis and tooth loss (2.5 [0.0-10.4] ng/ml, median [IQR]) compared to patients with periodontitis without tooth loss (6.0 [2.5-15.8] ng/ml, median [IQR], p = 0.04] and matched controls (7.0 [2.5-18.3] ng/ml, median [IQR], p = 0.02). No significant differences in sFRP5 serum levels were found among patients with periodontitis without tooth loss (6.0 [2.5-15.8] ng/ml, median [IQR]) and controls (3.1 [0.0-10.6] ng/ml, median [IQR], p = 0.06). CONCLUSIONS: sFRP5 might serve as a novel biomarker for periodontitis severity. Modulating the inflammatory background of severe forms of periodontitis, in the time of precision medicine, needs to be revealed in further studies.

TLR-induced immunomodulatory cytokine expression by human gingival stem/progenitor cells.

During therapeutic application, mesenchymal stem cells (MSCs) may interact with their environment via their expressed toll-like-receptors (TLRs) leading to pro- or anti-inflammatory immune responses. The present study aimed to describe the gingival margin-derived stem/progenitor cells' (G-MSCs) TLR-induced immune regulatory response to specific TLR agonists. Gingival cells were obtained, immunomagnetically sorted via anti-STRO-1 antibodies and seeded out to achieve colony forming units (CFUs). G-MSCs were investigated for stem cell characteristics and TLR expression. Specific TLR agonists were applied and m-RNA expression of pro- and anti-inflammatory factors was analyzed via real-time polymerase chain reaction. G-MSCs showed all characteristics of stem/progenitor cells. All TLR agonists induced pro-inflammatory cytokines, except for the TLR3 agonist, which significantly promoted the anti-inflammatory response. (p⩽0.05, Wilcoxon-Signed-Ranks-Test). TLR-induced immunomodulation by G-MSCs could impact their therapeutic potential in vivo. Two distinctive pro-inflammatory and an anti-inflammatory TLR-induced phenotypes of G-MSCs become noticeable in this study.