Microbiome of periodontitis and peri-implantitis before and after therapy: Long-read 16S rRNA gene amplicon sequencing.

AIMS: The microbial profiles of peri-implantitis and periodontitis (PT) are inconclusive. The controversies mainly arise from the differences in sampling sites, targeted gene fragment, and microbiome analysis techniques. The objective of this study was to explore the microbiomes of peri-implantitis (PI), control implants (CI), PT and control teeth (CT), and the microbial change of PI after nonsurgical treatment (PIAT). METHODS: Twenty-two patients diagnosed with both PT and peri-implantitis were recruited. Clinical periodontal parameters and radiographic bone levels were recorded. In each patient, the subgingival and submucosal plaque samples were collected from sites with PI, CI, PT, CT, and PIAT. Microbiome diversity was analyzed by high-throughput amplicon sequencing using full-length of 16S rRNA gene by next generation sequencing. RESULTS: The 16S rRNA gene sequencing analysis revealed 512 OTUs in oral microbiome and 377 OTUs reached strain levels. The PI and PT groups possessed their own unique core microbiome. Treponema denticola was predominant in PI with probing depth of 8-10 mm. Interestingly, Thermovirga lienii DSM 17291 and Dialister invisus DSM 15470 were found to associate with PI. Nonsurgical treatment for peri-implantitis did not significantly alter the microbiome, except Rothia aeria. CONCLUSION: Our study suggests Treponemas species may play a pivotal role in peri-implantitis. Nonsurgical treatment did not exert a major influence on the peri-implantitis microbiome in short-term follow-up. PT and peri-implantitis possess the unique microbiome profiles, and different therapeutic strategies may be suggested in the future.

Structure, physicochemical properties, and biological activities of protein hydrolysates from Zanthoxylum seed.

BACKGROUND: Zanthoxylum seed, as a low-cost and easily accessible plant protein resource, has good potential in the food industry. But protein and its hydrolysates from Zanthoxylum seed are underutilized due to the dearth of studies on them. This study aimed to investigate the structure and physicochemical and biological activities of Zanthoxylum seed protein (ZSP) hydrolysates prepared using Protamex®, Alcalase®, Neutrase®, trypsin, or pepsin. RESULTS: Hydrolysis using each of the five enzymes diminished average particle size and molecular weight of ZSP but increased random coil content. ZSP hydrolysate prepared using pepsin had the highest degree of hydrolysis (24.07%) and the smallest molecular weight (<13 kDa) and average particle size (129.80 nm) with the highest solubility (98.9%). In contrast, ZSP hydrolysate prepared using Alcalase had the highest surface hydrophobicity and foaming capacity (88.89%), as well as the lowest foam stability (45.00%). Moreover, ZSP hydrolysate prepared using Alcalase exhibited the best hydroxyl-radical scavenging (half maximal inhibitory concentration (IC50 ) 1.94 mg mL-1 ) and ferrous-ion chelating (IC50 0.61 mg mL-1 ) activities. Additionally, ZSP hydrolysate prepared using pepsin displayed the highest angiotensin-converting enzyme inhibition activity (IC50 0.54 mg mL-1 ). CONCLUSION: These data showed that enzyme hydrolysis improved the physicochemical properties of ZSP, and enzymatic hydrolysates of ZSP exhibited significant biological activity. These results provided validation for application of ZSP enzymatic hydrolysates as antioxidants and antihypertensive agents in the food or medicinal industries. © 2023 Society of Chemical Industry.

Structure, functional and physicochemical properties of lotus seed protein under different pH environments.

BACKGROUND: The present study investigated the structure, functional and physicochemical properties of lotus seed protein (LSP) under different pH environments. The structures of LSP were characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Fourier transform infrared spectroscopy (FTIR), zeta potential, particle size distributions, free sulfhydryl and rheological properties. The functional and physicochemical properties of LSP were characterized by color, foaming property, emulsification property, solubility, oil holding capacity, water holding capacity, differential scanning calorimetry analysis and surface hydrophobicity. RESULTS: LSP was mainly composed of eight subunits (18, 25, 31, 47, 51, 56, 65 and 151 kDa), in which the richest band was 25 kDa. FTIR results showed that LSP had high total contents of α-helix and ß-sheet (44.81-46.85%) in acidic environments. Meanwhile, there was more ß-structure and random structure in neutral and alkaline environments (pH 7.0 and 9.0). At pH 5.0, LSP had large particle size (1576.98 nm), high emulsion stability index (91.43 min), foaming stability (75.69%) and water holding capacity (2.21 g g-1), but low solubility (35.98%), free sulfhydryl content (1.95 µmol g-1) and surface hydrophobicity (780). DSC analysis showed the denaturation temperatures (82.23 °C) of LSP at pH 5.0 was higher than those (80.10, 80.52 and 71.82 °C) at pH 3.0, 7.0 and 9.0. The analysis of rheological properties showed that LSP gel had high stability and great strength in an alkaline environment. CONCLUSION: The findings of the present study are anticipated to serve as a valuable reference for the implementation of LSP in the food industry. © 2024 Society of Chemical Industry.

The structural characteristics and physicochemical properties of mung bean protein hydrolysate of protamex induced by ultrasound.

BACKGROUND: The limited physicochemical properties (such as low foaming and emulsifying capacity) of mung bean protein hydrolysate restrict its application in the food industry. Ultrasound treatment could change the structures of protein hydrolysate to accordingly affect its physicochemical properties. The aim of this study was to investigate the effects of ultrasound treatment on the structural and physicochemical properties of mung bean protein hydrolysate of protamex (MBHP). The structural characteristics of MBHP were evaluated using tricine sodium dodecylsulfate-polyacrylamide gel electrophoresis, laser scattering, fluorescence spectrometry, etc. Solubility, fat absorption capacity and foaming, emulsifying and thermal properties were determined to characterize the physicochemical properties of MBHP. RESULTS: MBHP and ultrasonicated-MBHPs (UT-MBHPs) all contained five main bands of 25.8, 12.1, 5.6, 4.8 and 3.9 kDa, illustrating that ultrasound did not change the subunits of MBHP. Ultrasound treatment increased the contents of α-helix, ß-sheet and random coil and enhanced the intrinsic fluorescence intensity of MBHP, but decreased the content of ß-turn, which demonstrated that ultrasound modified the secondary and tertiary structures of MBHP. UT-MBHPs exhibited higher solubility, foaming capacity and emulsifying properties than MBHP, among which MBHP-330 W had the highest solubility (97.32%), foaming capacity (200%), emulsification activity index (306.96 m2 g-1 ) and emulsion stability index (94.80%) at pH 9.0. CONCLUSION: Ultrasound treatment enhanced the physicochemical properties of MBHP, which could broaden its application as a vital ingredient in the food industry. © 2023 Society of Chemical Industry.

Chlorhexidine gel topical application ameliorates inflammatory bone loss in experimental periodontitis.

OBJECTIVES: This study aimed to evaluate the impact of chlorhexidine (CHX) gel on inflammation-induced periodontal tissue destruction, osteoclastogenesis, subgingival microbiota, and on the modulation of the RANKL/OPG as well as inflammatory mediators during bone remodeling in vivo. MATERIALS AND METHODS: Ligation- and LPS injection-induced experimental periodontitis were created to investigate the effect of topical application of CHX gel in vivo. Alveolar bone loss, osteoclast number and gingival inflammation was evaluated by micro-CT, histological, immunohistochemistry and biochemical analysis. The composition of the subgingival microbiota was characterized by 16S rRNA gene sequencing. RESULTS: Data shows significant decreases in the alveolar bone destruction in rats from ligation-plus-CHX gel group compared to ligation group. In addition, significant decreases in the number of osteoclasts on bone surface and the protein level of receptor activator of nuclear factor κB ligand (RANKL) in gingival tissue were observed in rats from ligation-plus-CHX gel group. Moreover, data shows significantly decreased inflammatory cell infiltration and decreased expression of cyclooxygenase (COX-2) and inducible NO synthase (iNOS) in gingival tissue from ligation-plus-CHX gel group versus ligation group. Assessment of the subgingival microbiota revealed changes in rats with CHX gel application treatment. CONCLUSION: HX gel presents protective effect on gingival tissue inflammation, osteoclastogenesis, RANKL/OPG expression, inflammatory mediators, and alveolar bone loss in vivo, which may have a translational impact on the adjunctive use in the management of inflammation-induced alveolar bone loss.

Stimulation phosphatidylinositol 3-kinase/protein kinase B signaling by Porphyromonas gingivalis lipopolysacch aride mediates interleukin-6 and interleukin-8 mRNA/protein expression in pulpal inflammation.

BACKGROUND/PURPOSE: The signaling mechanisms for Porphyromonas gingivalis lipopolysaccharide (PgLPS)-induced inflammation in human dental pulp cells are not fully clarified. This in vitro study aimed to evaluate the involvement of phosphatidylinositol 3-kinase (PI3K)/protein kinase B (Akt) pathway in PgLPS-induced pulpal inflammation. METHODS: Human dental pulp cells (HDPCs) were challenged with PgLPS with or without pretreatment and coincubation with a PI3K/Akt inhibitor (LY294002). The gene or protein levels of PI3K, Akt, interleukin (IL)-6, IL-8, alkaline phosphatase (ALP), osteocalcin and osteonectin were analyzed by reverse transcription polymerase chain reaction (PCR), real-time PCR, western blotting, and immunofluorescent staining. In addition, an enzyme-linked immunosorbent assay was used to analyze IL-6 and IL-8 levels in culture medium. RESULTS: In response to 5 µg/ml PgLPS, IL-6, IL-8, and PI3K, but not Akt mRNA expression of HDPCs, was upregulated. IL-6, IL-8, PI3K, and p-Akt protein levels were stimulated by 10-50 µg/ml of PgLPS in HDPCs. PgLPS also induced IL-6 and IL-8 secretion at concentrations higher than 5 µg/ml. Pretreatment and co-incubation by LY294002 attenuated PgLPS-induced IL-6 and IL-8 mRNA expression in HDPCs. The mRNA expression of ALP, but not osteocalcin and osteonectin, was inhibited by higher concentrations of PgLPS in HDPCs. CONCLUSION: P. gingivalis contributes to pulpal inflammation in HDPCs by dysregulating PI3K/Akt signaling pathway to stimulate IL-6 and IL-8 mRNA/protein expression and secretion. These results are useful for understanding the pulpal inflammation and possible biomarkers of inflamed pulp diagnosis and treatment.

[Cloning and expression analysis of U6 promoters in Panax quinquefolius].

The U6 promoter is an important element driving sgRNA transcription in the CRISPR/Cas9 system. Seven PqU6 promo-ter sequences were cloned from the gDNA of Panax quinquefolium, and the transcriptional activation ability of the seven promoters was studied. In this study, seven PqU6 promoter sequences with a length of about 1 300 bp were cloned from the adventitious roots of P. quinquefolium cultivated for 5 weeks. Bioinformatics tools were used to analyze the sequence characteristics of PqU6 promoters, and the fusion expression vectors of GUS gene driven by PqU6-P were constructed. Tobacco leaves were transformed by Agrobacterium tumefaciens-mediated method for activity detection. The seven PqU6 promoters were truncated from the 5'-end to reach 283, 287, 279, 289, 295, 289, and 283 bp, respectively. The vectors for detection of promoter activity were constructed with GUS as a reported gene and used to transform P. quinquefolium callus and tobacco leaves. The results showed that seven PqU6 promoter sequences(PqU6-1P to PqU6-7P) were cloned from the gDNA of P. quinquefolium, with the length ranged from 1 246 bp to 1 308 bp. Sequence comparison results showed that the seven PqU6 promoter sequences and the AtU6-P promoter all had USE and TATA boxes, which are essential elements affecting the transcriptional activity of the U6 promoter. The results of GUS staining and enzyme activity test showed that all the seven PqU6 promoters had transcriptional activity. The PqU6-7P with a length of 1 269 bp had the highest transcriptional activity, 1.31 times that of the positive control P-35S. When the seven PqU6 promoters were truncated from the 5'-end(PqU6-1PA to PqU6-7PA), their transcriptional activities were different in tobacco leaves and P. quinquefolium callus. The transcriptional activity of PqU6-7PA promoter(283 bp) was 1.59 times that of AtU6-P promoter(292 bp) when the recipient material was P. quinquefolium callus. The findings provide more ideal endogenous U6 promoters for CRISPR/Cas9 technology in ginseng and other medicinal plants.

Adjunctive local treatments for patients with residual pockets during supportive periodontal care: A systematic review and network meta-analysis.

AIM: This systematic review and network meta-analysis aimed to evaluate the efficacy of adjunctive locally delivered antimicrobials, compared to subgingival instrumentation alone or plus a placebo, on changes in probing pocket depth (PPD) and clinical attachment level (CAL), in patients with residual pockets during supportive periodontal care. MATERIALS AND METHODS: Literature search was performed with electronic databases and by hand until 31 May 2020. Primary outcome was the changes in PPD. The treatment effects between groups were estimated with weighted mean differences (WMD) with 95% confidence intervals (CI) and prediction intervals (PI) by using random-effects network meta-analysis. RESULTS: Twenty-two studies were included. Significantly greater PPD reduction was achieved in chlorhexidine chip group (WMD: 0.65 mm, 95% CI: 0.21-1.10) and tetracycline fibre group (WMD: 0.64 mm, 95% CI: 0.20-1.08) over 6-month follow-up. Other adjunctive antimicrobial agents achieved non-significant improvements compared to scaling and root planing alone. All differences between adjunctive therapies were statistically non-significant. Similar findings were observed for CAL gain. CONCLUSION: Adjunctive local antimicrobial agents achieved small additional PPD reduction and CAL gain in residual pockets for a follow-up of up to 6 months. Tetracycline fibre and chlorhexidine chip achieved better results than other antimicrobials.

Association of initial mucogingival status with clinical outcome of non-surgical periodontal therapy: A retrospective analysis of 204 patients.

BACKGROUND/PURPOSE: This study was conducted to evaluate the influence of mucogingival parameters, including keratinized mucosa (KM) and attached gingiva (AG), on the outcome of non-surgical periodontal therapy (NSPT). METHODS: A total of 204 non-smoking patients with generalized chronic periodontitis who received NSPT between 2012 and 2014 were included. The Mantel-Haenszel chi-square test was used to assess the associations between initial mucogingival parameters and initial clinical parameters on the buccal aspect, and the associations between initial mucogingival parameters and outcome clinical parameters on the buccal aspect of the sites with severe periodontal destruction. The generalized liner model was used to evaluate the contribution of initial clinical parameters to the outcome of NSPT. RESULTS: KM ≥ 3 mm was associated with greater probing pocket depth (PD), less gingival recession (REC), and less clinical attachment level (CAL), and AG < 1 mm was associated with greater PD, REC, and CAL before NSPT. At the sites with severe periodontal destruction, KM ≥ 3 mm was associated with greater PD reduction (0.25 ± 0.08 mm) and CAL gain (0.25 ± 0.09 mm), and AG < 1 mm was associated with greater CAL gain (0.15 ± 0.08 mm) after NSPT. Initial PD ≥ 7 mm and non-molar teeth showed greater contribution to the outcome of NSPT. CONCLUSION: Less AG (<1 mm) was associated with greater periodontal destruction at baseline. At the sites with severe periodontal destruction, greater KM (≥3 mm) and less AG (<1 mm) resulted in better outcomes of NSPT.

Staged orthodontic treatment in preparation for immediate implant placement: A clinical report with a 5-year follow-up.

Anterior implant restoration is one of the most challenging restorative procedures, especially for sites with vertical and/or horizontal hard and soft tissue deformities. Orthodontic extrusion before implant placement may be the best means of overcoming vertical deficiencies. This article describes a modification to the standard technique, involving staged orthodontic extrusion and buccal root torque. The main advantage of this modification is that it encourages bone and soft tissue development, thereby allowing the patient to receive immediate or early implant treatment. A clinical procedure is presented to illustrate the modified technique that resulted in an esthetically pleasing and stable 5-year outcome.

Curcumin inhibits TGF-ß1-induced connective tissue growth factor expression through the interruption of Smad2 signaling in human gingival fibroblasts.

BACKGROUND/PURPOSE: Many fibrotic processes are associated with an increased level of transforming growth factor-ß1 (TGF-ß1). TGF-ß1 can increase synthesis of matrix proteins and enhance secretion of protease inhibitors, resulting in matrix accumulation. Connective tissue growth factor (CTGF) is a downstream profibrotic effector of TGF-ß1 and is associated with the fibrosis in several human organs. Curcumin has been applied to reduce matrix accumulation in fibrotic diseases. This study was aimed to evaluate whether curcumin could suppress TGF-ß1-induced CTGF expression and its related signaling pathway involving in this inhibitory action in primary human gingival fibroblasts. METHODS: The differences in CTGF expression among three types of gingival overgrowth and normal gingival tissues were assessed by immunohistochemistry. Gingival fibroblast viability in cultured media with different concentrations of curcumin was studied by MTT assay. The effect of curcumin on TGF-ß1-induced CTGF expression in primary human gingival fibroblasts was examined by immunoblotting. Moreover, the proteins involved in TGF-ß1 signaling pathways including TGF-ß1 receptors and Smad2 were also analyzed by immunoblotting. RESULTS: CTGF was highly expressed in fibroblasts, epithelial cells and some of endothelial cells, smooth muscle cells, and inflammatory cells in phenytoin-induced gingival overgrowth tissues rather than in those of hereditary and inflammatory gingival overgrowth tissues. Moreover, CTGF expression in the epithelial and connective tissue layers was higher in phenytoin-induced gingival overgrowth tissues than in normal gingival tissues. Curcumin was nontoxic and could reduce TGF-ß1-induced CTGF expression by attenuating the phosphorylation and nuclear translocation of Smad2. CONCLUSION: Curcumin can suppress TGF-ß1-induced CTGF expression through the interruption of Smad2 signaling.

Significant association of rheumatoid arthritis-related inflammatory markers with non-surgical periodontal therapy.

BACKGROUND/PURPOSE: Chronic periodontitis (CP) and rheumatoid arthritis (RA) are the most common chronic inflammatory diseases and their immunopathogenesis is similar. The aim of this study was to evaluate the effect of non-surgical periodontal treatment on the serum levels of RA-related inflammatory markers in patients with chronic periodontitis. METHODS: Thirty-one Taiwanese adults with CP were included. Demographics and periodontal parameters, including probing depth, clinical attachment level, and number of remaining teeth in the oral cavity, were recorded. All subjects received non-surgical periodontal treatment such as scaling and subgingival root planing. Serum samples were collected before and after the treatment. Serum levels of anti-citrullinated protein antibodies (ACPA), rheumatoid factor, tumor necrosis factor-α (TNF-α), C-reactive protein, interleukin-1ß (IL-1ß), and Interleukin-6 (IL-6) were measured using an enzyme-linked immunosorbent assay. RESULTS: Non-surgical periodontal treatment significantly reduced the serum ACPA (p = 0.015) and TNF-α levels (p = 0.026) in CP patients, particularly in patients with generalized CP. Furthermore, there was a significant and positive correlation between the number of extracted teeth and the reduction in the serum ACPA (p = 0.05) and IL-1ß levels (p = 0.029) after non-surgical periodontal treatment. CONCLUSION: Non-surgical periodontal therapy may aid in the control of RA-related inflammatory markers in patients with CP. A large-scale study with well-defined populations is needed to clarify the benefit of non-surgical periodontal therapy.

Lasers in minimally invasive periodontal and peri-implant therapy.

Laser therapy has the potential to be an effective, minimally invasive procedure in periodontal therapy. The aim of the present review was to survey the relevant literature on the clinical application of lasers as a minimally invasive treatment for periodontitis and peri-implant disease. Currently, there are a large number of published clinical studies and case reports that evaluate the adjunctive use of diode, carbon dioxide, neodymium-doped yttrium aluminium garnet (Nd:YAG), erbium-doped yttrium aluminium garnet (Er:YAG) and erbium, chromium-doped: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) lasers or antimicrobial photodynamic therapy for nonsurgical and minimally invasive surgical treatment of periodontal pockets. These procedures are expected not only to control inflammation but also to provide biostimulation effects with photonic energy. Recent meta-analyses did not show statistically significant differences in pocket reduction and clinical attachment gain compared with mechanical debridement alone, although limited positive effects of adjunctive laser therapy were reported. At present, systematic literature approaches suggest that more evidence-based studies need to be performed to support the integration of various laser therapies into the treatment of periodontal and peri-implant diseases. The disparity between previous statistical analyses and individual successful clinical outcomes of laser applications might reveal the necessity of developing optimal laser-treatment modalities of different wavelengths and better-defined indications for each protocol.

Controlling periodontal bone levels with multiple LED irradiations.

Because a single exposure to light-emitting diode (LED) irradiation at 660 nm only demonstrated a 3-day biostimulatory effect in recovering periodontal bone level (PBL), this study sought to evaluate whether the periodontal effect could be extended through the use of multiple LED irradiations. Experimental periodontitis was developed unilaterally in 48 Sprague-Dawley rats after the placement of a silk ligature plus Porphyromonas gingivalis lipopolysaccharide injections. The animals were divided into four groups (no irradiation, a single irradiation, or two or three irradiations per week) and exposed to LED light irradiation at a wavelength of 660 ± 25 nm and energy density of 10 J/cm(2) after debridement and detoxification. The animals were euthanized after 7 or 14 days, and the effect of irradiation was evaluated using micro-computed tomography and histology. By day 7, PBL was significantly reduced (p < 0.05), with significantly reduced inflammation (p < 0.05) and gingival hyperplasia (p < 0.001), in the animals receiving three irradiations per week. At day 14, the reduction in gingival hyperplasia was still significant (p < 0.05), and collagen matrix deposition and realignment appeared to be accelerated in the animals receiving three irradiations per week, despite a lack of significant difference in PBL. The treatment regimen receiving three LED light irradiations per week apparently extended the effects in reducing PBL and inflammation to 7 days. The inclusion of additional inflammation control measures or the addition of bioactive signals to mediate the repairing process is necessary to maintain long-term periodontal stability.

Osseous wound repair under inhibition of the axis of advanced glycation end-products and the advanced glycation end-products receptor.

BACKGROUND/PURPOSE: Blockade of advanced glycation end-products (AGE) is able to reduce diabetic complications and control periodontitis. This study aimed to determine whether the application of aminoguanidine (AG), an AGE inhibitor, or N-phenacylthiazolium bromide (PTB), an AGE breaker, facilitates the healing of an osseous wound in non-diabetic animals. METHODS: 2.6 mm diameter full-thickness osseous wounds were created bilaterally in 54 healthy Sprague-Dawley rats. Rats received daily normal saline, AG, or PTB injections respectively and were euthanized after 7 days, 14 days, or 28 days (n = 6). The wound healing pattern was assessed by micro-computed tomography, histology, histochemistry for the fiber arrangement, and the gene expression levels of AGE receptor, tumor necrosis factor-α, type I collagen, and fibronectin. RESULTS: Under the AG and PTB administration, osteogenesis was apparently promoted in the early stages of healing, but the union of the osseous wound and the fibril re-arrangement was apparently retarded. No significant difference was found in any of the micro-computed tomography parameters as compared to the control in the first 14 days, whereas the relative bone volume was significantly higher in the control at Day 28. AGE receptor and tumor necrosis factor-α were depressed in the PTB group, but only temporarily at Day 14 in the AG group. Therefore, at Day 14, type I collagen was significantly upregulated in the PTB group, and fibronectin was significantly increased in the AG group. CONCLUSION: Anti-AGE agents reduced inflammation but did not apparently facilitate osteogenesis during the osseous wound repair.

[The Characteristic Research of ·OH Induced by Water on an Argon Plasma Jet].

·OH plays a crucial role in many fields, having aroused wide public concern in the world. Atmospheric Pressure Plasma Jet, which can be achieved by portable device due to working without the vacuum environment, has the advantages of high concentration of reactive species, high electron temperature and low gas temperature. It has become an important research topic in the field of gas discharge with a strong prospect. Especially, how to induce plasma jet to produce ·OH has become a new hotpot in the field of low-temperature plasma. It has been reported that mass ·OH can be induced successfully when water vapor is added to the working gas, but it will be unstable when the concentrate of water reaches a certain degree. Thus, a device of argon plasma jet with a Ring-to-Ring Electrode Configuration has been designed to interact with water in the surrounding air to generate ·OH under atmospheric pressure. In order to increase the production of ·OH, ultrasonic atomizing device is introduced to promote water concentration around the plasma plume. The generating rule of OH(A2J) induced by water has been extensively studied under different voltages and flow rate. ·OH output induced by the plasma has been tested by emission spectrometry, and at the meanwhile, Ar atomic spectral lines at 810.41 and 811.48 nm are also recorded in order to calculate the electron temperature in argon plasma plume. The results show that the water surrounding the plasma plume can be induced to produce ·OH, and OH(A2 ∑+) output increases with the electrode voltage rising from 20 to 28 kV. When the flow rate increases from 100 to 200 L x h(-1), the OH(A2∑+) output increases, but from 200 to 600 L x h(-1), it decreases. The production rules of OH(A2∑+) is the same as that of electron temperature. Therefore, the presumption is proved that ·OH output mainly affected by electron temperature.

Combination of LED light and platelet-derived growth factor to accelerate dentoalveolar osteogenesis.

AIM: This study aimed to evaluate the adjunctive effect of LED light in platelet-derived growth factor (PDGF)-aided dentoalveolar osteogenesis. MATERIAL AND METHODS: Full-thickness osseous wounds were created on rat maxillae and were either unfilled or filled with poly-(D,L-lactide) and poly-(D,L-lactide-co-glycolide) microspheres encapsulating PDGF. Animals received daily 660 ± 25 nm LED light irradiation at 0, 10 (LD), or 20 (HD) J/cm(2) , were killed at days 4-28 (n = 6/group/time) and evaluated by microcomputed tomography (micro-CT), histology, and the expressions of osteopontin and tartrate-resistant acid phosphatase (TRAP). RESULTS: Greater osteogenesis was noted in the PDGF-treated defects at day 14. Under the LED light irradiation, osteogenesis was significantly greater in both LD and HD groups of the non-PDGF-treated defects, but only in the LD group of the PDGF-treated defects. No significant differences in osteogenesis among groups were noted at day 28. Greater bone marrow space was noted in the LED light-irradiated specimens, especially in the PDGF-treated defects at both time points. Osteopontin was significantly promoted in the LD group at both time points, and TRAP was significantly promoted in all LED light-irradiated groups at day 28. CONCLUSION: LED light could an adjunct to promote early PDGF-aided dentoalveolar osteogenesis by facilitating the osteoblast-osteoclast coupling.

Epigallocatechin-3-gallate inhibits lysophosphatidic acid-stimulated connective tissue growth factor via JNK and Smad3 suppression in human gingival fibroblasts.

BACKGROUND/PURPOSE: Connective tissue growth factor (CTGF/CCN2) is involved in the development and progression of fibrotic diseases, including gingival overgrowth (GO). Recent studies indicate that lysophosphatidic acid (LPA) is also significantly involved in wound healing and the development of fibrosis. This study investigated whether epigallocatechin-3-gallate (EGCG) can inhibit LPA-induced CCN2 expression in human gingival fibroblast (GF) and its mechanism. METHODS: Western blot analyses were used to study the signaling pathways of LPA-induced CCN2 expression in human GFs and the effects of EGCG on this pathway. RESULTS: LPA stimulated CCN2 synthesis in human GFs. This effect can be significantly inhibited bytransforming growth factor-ß type I receptor/ALK5, Smad3, and JNK inhibitors but not ERK, P38, and MAPK inhibitors. EGCG completely inhibited LPA-induced CCN2 expression through attenuating the LPA-induced JNK and Smad3 phosphorylation in human GFs. CONCLUSION: LPA produced at the surgical wound may contribute to the recurrence of GO by upregulating CCN2 expression in human GFs. This effect was mediated by Smad3 and JNK activation and ALK5 transactivation. EGCG could be a useful agent for reducing the recurrence of GO after surgery through suppression of JNK and Smad3 activations.

Surgical repair of external cervical resorption - Prognosis and prognostic factors.

Background/purpose: External cervical resorption (ECR) is an aggressive form of root resorption, which etiology is unclear and its prognosis remains unpredictable. The purpose of this study was to investigate the prognosis and potential prognostic factors of ECR-affected teeth after surgical intervention for external repair with/without root canal treatment. Materials and methods: Treated ECR cases from 2009 to 2019 were collected retrospectively. The survival of the teeth and the status of root resorption were assessed during the follow-up period. Potential prognostic factors were analyzed with log-rank test and Kaplan-Meier statistics. Results: A total of 42 treated ECR-affected teeth were enrolled. The two-year survival rate was 71.20% [54.16%, 93.59%]. Persistent root resorption was the main complication after treatment. Patients with multiple ECR-affected teeth had greater recurrent potential than patients with solitary ECR-affected teeth. Prolonged calcium hydroxide dressing may contribute to a more favorable clinical outcome. Gender, age, tooth position and the need for root canal treatment did not show statistically significant effect on the prognosis. Conclusion: The current surgical method was able to arrest ECR in most cases. However, the case type (the number of ECR-affected teeth per patient) could highly affect the prognosis of the teeth. Clinicians should consider long-term calcium hydroxide dressing in case of pulp involvement to achieve better results.

Epigallocatechin gallate-immobilized antimicrobial resin with rechargeable fluorinated synergistic composite for enhanced caries control.

OBJECTIVES: Given the global prevalence of dental caries, impacting 2.5 billion individuals, the development of sophisticated prevention filling materials is crucial. Streptococcus mutans, the principal caries-causing strain, produces acids that demineralize teeth and initiate dental caries. To address this issue, we aimed to develop a synergistic resin-based composite for enhancing caries control. METHODS: The synergistic resin composite incorporates fluorinated kaolinite and silanized Al2O3 nanoparticle fillers into an epigallocatechin gallate (EGCG) immobilized urethane-modified epoxy acrylate (U-EA) resin matrix, referred to the as-prepared resin composite. The EGCG-modified TPGDA/U-EA network was synthesized by preparing methacrylate-functionalized isocyanate (HI), reacting it with EGCG to form HI-EGCG, and then incorporating HI-EGCG into the TPGDA/U-EA matrix. The lamellar space within the kaolinite layer was expanded through the intercalation of acrylamide into kaolinite, enhancing its capability to adsorb and release fluoride ions (F-). The layered structure of acrylamide/ kaolinite in the U-EA resin composite acts as a F- reservoir. RESULTS: The physico-mechanical properties of the as-prepared resin composites are comparable to those of commercial products, exhibiting lower polymerization shrinkage, substantial F- release and recharge and favorable diametral tensile strength. The immobilized EGCG in the composite exhibits potent antimicrobial properties, effectively reducing the biofilm biomass. Furthermore, the synergistic effect of EGCG and fluorinated kaolinite efficiently counteracts acid-induced hydroxyapatite dissolution, thereby suppressing demineralization and promoting enamel remineralization. SIGNIFICANCE: Our innovative EGCG and fluoride synergistic composite provides enhanced antimicrobial properties, durable anti-demineralization, and tooth remineralization effects, positioning it as a promising solution for effective caries control and long-term dental maintenance.