Gene expression, micro-CT and histomorphometrical analysis of sinus floor augmentation with biphasic calcium phosphate and deproteinized bovine bone mineral: A randomized controlled clinical trial.

AIMS: The aim of this randomized controlled clinical trial was to compare the gene expression, micro-CT, histomorphometrical analysis between biphasic calcium phosphate (BCP) of 70/30 ratio and deproteinized bovine bone mineral (DBBM) in sinus augmentation. MATERIALS AND METHODS: Twenty-four patients in need for sinus floor augmentation through lateral approach were randomized into BCP 70/30 ratio or DBBM. After at least 6 months of healing, a total of 24 bone specimens were collected from the entire height of the augmented bone at the area of implant placement and underwent micro-CT, histomorphometric and gene expression analysis. The 12 bone specimens of BCP 70/30 ratio were equally allocated to micro-CT and histologic analysis (test group, n = 6) and gene expression analysis (test group, n = 6). Similarly, the 12 bone specimens of DBBM were also allocated to micro-CT and histologic analysis (control group, n = 6) and gene expression analysis (control group, n = 6). The newly formed bone, remaining graft materials and relative change in gene expression of four target genes were assessed. RESULTS: The micro-CT results showed no statistically significant difference in the ratio of bone volume to total volume (BV/TV ratio) for the two groups (BCP 41.51% vs. DBBM 40.97%) and the same was true for residual graft material to total volume (GV/TV ratio, BCP 9.97% vs. DBBM 14.41%). Similarly, no significant difference was shown in the histological analysis in terms of bone formation, (BCP 31.43% vs. DBBM was 30.09%) and residual graft area (DBBM 40.76% vs. BCP 45.06%). With regards to gene expression, the level of ALP was lower in both groups of bone grafted specimens compared with the native bone. On the contrary, the level of OSX, IL-1B and TRAP was higher in augmented bone of both groups compared with the native bone. However, the relative difference in all gene expressions between BCP and DBBM group was not significant. CONCLUSIONS: The BCP, HA/ß-TCP ratio of 70/30 presented similar histological and micro-CT outcomes in terms of new bone formation and residual graft particles with DBBM. The gene expression analysis revealed different gene expression patterns between augmented and native bone, but showed no significant difference between the two biomaterials.

Partial pulpotomy success in primary molars followed up for 24 months: A randomized controlled clinical trial using mineral trioxide aggregate, biodentine, and acemannan.

BACKGROUND: Finding the best treatment approach and suitable capping materials in primary molars with deep carious lesions remains unresolved. AIM: To compare the success rates of partial pulpotomy in deep caries lesions in primary molars treated with mineral trioxide aggregate (MTA), biodentine, or acemannan for 6-24 months. DESIGN: A parallel-design, non-inferiority randomized controlled clinical trial was performed. Ninety mandibular primary molars from 65 children meeting the criteria, aged 3-8 years, were included. After inflamed pulp tissue removal and hemostasis, each tooth was randomly allocated into the MTA control group, or the biodentine or acemannan experimental group (N = 30 per group). All teeth were restored with a stainless steel crown. The outcomes were evaluated for 6-24 months. A generalized estimating equation model was used to compare the overall success rate in each group. RESULTS: After 24 months, 58 children (83 teeth) were available for evaluation. The results indicated that the success rate in the MTA, biodentine, and acemannan groups was 83.3%, 76.9%, and 74.1%, respectively. No significant difference in success rates among groups, however, was observed at the 6- to 24-month follow-ups (at 24th month, p = .30). CONCLUSION: There was no statistically significant difference between MTA, biodentine, or acemannan in the partial pulpotomy success after 24 months.

Development of poly(methyl methacrylate)/poly(lactic acid) blend as sustainable biomaterial for dental applications.

Poly(lactic acid) (PLA) is gaining popularity in manufacturing due to environmental concerns. When comparing to poly(methyl methacrylate) (PMMA), PLA exhibits low melting and glass transition temperature (Tg). To enhance the properties of these polymers, a PMMA/PLA blend has been introduced. This study aimed to investigate the optimal ratio of PMMA/PLA blends for potential dental applications based on their mechanical properties, physical properties, and biocompatibility. The PMMA/PLA blends were manufactured by melting and mixing using twin screw extruder and prepared into thermoplastic polymer beads. The specimens of neat PMMA (M100), three different ratios of PMMA/PLA blends (M75, M50, and M25), and neat PLA (M0) were fabricated with injection molding technique. The neat polymers and polymer blends were investigated in terms of flexural properties, Tg, miscibility, residual monomer, water sorption, water solubility, degradation, and biocompatibility. The data was statistically analyzed. The results indicated that Tg of PMMA/PLA blends was increased with increasing PMMA content. PMMA/PLA blends were miscible in all composition ratios. The flexural properties of polymer blends were superior to those of neat PMMA and neat PLA. The biocompatibility was not different among different composition ratios. Additionally, the other parameters of PMMA/PLA blends were improved as the PMMA ratio decreased. Thus, the optimum ratio of PMMA/PLA blends have the potential to serve as novel sustainable biomaterial for extensive dental applications.

Stability of guided bone regeneration with two ratios of biphasic calcium phosphate at implant sites in the esthetic zone: A randomized controlled clinical trial.

AIMS: The aim of this randomized, double-blind, clinical trial was to compare the stability of the horizontal dimensions (facial bone thickness) of augmented bone using biphasic calcium phosphate (BCP) with hydroxyapatite/ß-tricalcium phosphate ratio of either 60/40 or 70/30. MATERIALS AND METHODS: Sixty dental implants placed with contour augmentation in the esthetic zone were randomized to 60/40 BCP (n = 30) or 70/30 BCP (n = 30). Cone-beam computed tomographic was used to assess facial bone thickness post-implantation and 6 months later at implant platform and 2, 4, and 6 mm apical to it. RESULTS: The percentage of horizontal dimension reduction was 23.64%, 12.83%, 9.62%, and 8.21% in 70/30 BCP group, while 44.26%, 31.91%, 25.88%, and 21.49% in 60/40 BCP group at the level of the implant platform and 2, 4, and 6 mm apical, respectively. Statistically significant difference was found at 6 months at all levels of measurement (p-value < .05). CONCLUSIONS: BCP bone grafts with HA/ß-TCP ratio of 60/40 and 70/30 showed comparable outcomes for contour augmentation simultaneously with implant placement. Interestingly, the 70/30 ratio was significantly superior in maintaining facial thickness and showed more stable horizontal dimensions of the augmented site.

Characterization of a bioscaffold containing polysaccharide acemannan and native collagen for pulp tissue regeneration.

Dental pulp regeneration exploits tissue engineering concepts using stem cells/scaffolds/growth-factors. Extracted collagen is commonly used as a biomaterial-scaffold due to its biocompatibility/biodegradability and mimics the natural extracellular matrix. Adding biomolecules into a collagen-scaffold enhanced pulp regeneration. Acemannan, ß-(1-4)-acetylated-polymannose, is a polysaccharide extracted from aloe vera. Acemannan is a regenerative biomaterial. Therefore, acemannan could be a biomolecule in a collagen-scaffold. Here, acemannan and native collagen were obtained and characterized. The AceCol-scaffold's physical properties were investigated using FTIR, SEM, contact angle, swelling, pore size, porosity, compressive modulus, and degradation assays. The AceCol-scaffold's biocompatibility, growth factor secretion, osteogenic protein expression, and calcification were evaluated in vitro. The AceCol-scaffolds demonstrated higher hydrophilicity, swelling, porosity, and larger pore size than the collagen scaffolds (p < 0.05). Better cell-cell and cell-scaffold adhesion, and dentin extracellular matrix protein (BSP/OPN/DSPP) expression were observed in the AceCol-scaffold, however, DSPP expression was not detected in the collagen group. Significantly increased cellular proliferation, VEGF and BMP2 expression, and mineralization were detected in the AceCol-scaffold compared with the collagen-scaffold (p < 0.05). Computer simulation revealed that acemannan's 3D structure changes to bind with collagen. In conclusion, the AceCol-scaffold synergistically provides better physical and biological properties than collagen. The AceCol-scaffold is a promising material for tissue regeneration.

Acemannan-induced tooth socket healing: A 12-month randomized controlled trial.

BACKGROUND/PURPOSE: Natural compounds have become alternatives for bone regeneration. Acemannan, the main polysaccharide extracted from Aloe vera, has been demonstrated as a promising osteoinductive material in vitro and in vivo. This clinical study investigated the effect of acemannan on tooth socket healing. MATERIALS AND METHODS: Thirty-five otherwise healthy patients, 18-25 years old and diagnosed with horizontal or vertical partial impaction of the lower third molars, were enrolled in this randomized controlled trial. After removing the teeth, the sockets randomly received one of the following treatments: spontaneous blood-clotting (control), 20 mg acemannan sponge, or 50 mg acemannan sponge. Cone-beam computed tomography of the mandible was performed immediately (baseline), and at 3-, 6-, and 12-months postoperatively; the data were analyzed using the OsiriX MD program. Bone healing in the socket was determined measuring the socket volume. One-way ANOVA was used to analyze the differences within each group and between groups. RESULTS: Thirty-five patients with 43 partially impacted lower third molars participated in this study. No patients exhibited alveolar osteitis or secondary infection. Compared with baseline, all groups showed significant reduction in socket volume at all observation time-points (p < 0.05). The 50 mg acemannan group had a significantly greater reduction in socket volume compared with the control at all postoperative time-points (p < 0.05). The 20 mg group had a significantly greater reduction in socket volume compared with the control at 3-months postoperatively (p < 0.05). CONCLUSION: We conclude that acemannan increases bone healing at 3-, 6-, and 12-months after removal of partially impacted mandibular third molars.

Peri-implantitis Update: Risk Indicators, Diagnosis, and Treatment.

Despite the success rates of dental implants, peri-implantitis presents as the most common complication in implant dentistry. This review discusses various factors associated with peri-implantitis and various available treatments, highlighting their advantages and disadvantages. Relevant articles on peri-implantitis published in English were reviewed from August 2010 to April 2020 in MEDLINE/PubMed, Scopus, and ScienceDirect. The identified risk indicators of peri-implant diseases are plaque, smoking, history of periodontitis, surface roughness, residual cement, emergence angle >30 degrees, radiation therapy, keratinized tissue width, and function time of the implant, sex, and diabetes. Peri-implantitis treatments can be divided into nonsurgical (mechanical, antiseptic, and antibiotics), surface decontamination (chemical and laser), and surgical (air powder abrasive, resective, and regenerative). However, mechanical debridement alone may fail to eliminate the causative bacteria, and this treatment should be combined with other treatments (antiseptics and surgical treatment). Surface decontamination using chemical agents may be used as an adjuvant treatment; however, the definitive clinical benefit is yet not proven. Laser treatment may result in a short-term decrease in periodontal pocket depth, while air powder abrasive is effective in cleaning a previously contaminated implant surface. Surgical elimination of a pocket, bone recontouring and plaque control are also effective for treating peri-implantitis. The current evidence indicates that regenerative approaches to treat peri-implant defects are unpredictable.

Acemannan induces rapid early osseous defect healing after apical surgery: A 12-month follow-up of a randomized controlled trial.

BACKGROUND/PURPOSE: Acemannan is an osteoinductive material. This study's objective was to compare the outcomes of bone defect healing using 3-dimensional images after apical surgery with or without adding acemannan sponges. MATERIALS AND METHODS: Twenty-two anterior teeth from 9 males and 13 females requiring apical surgery were included in this randomized controlled trial. Post-surgery, the bone defects were randomly divided into three groups: blood clot control, 5-, or 10-mg acemannan sponge groups. CBCT scans were taken immediately (baseline), 3-, 6-, and 12-month post-surgery. Sagittal serial sections (1 mm thick slices parallel to the long axis of the tooth) of the defect image were created. The defect boundary was located and the total bone defect volume (BDV) was calculated from the sum of the volume of the serial defect sections. The bone healing was assessed by the percentage of total bone defect volume reduction (%ΔBDV). The paired t-test and one-way ANOVA were used to analyze the differences within each group and between groups, respectively. RESULTS: The baseline mean BDV of the control, 5-, and 10-mg acemannan groups were not significantly different (p > 0.05). After treatment, the mean BDV for each group was reduced in a time-dependent manner. Compared with the control group, the 5- and 10-mg acemannan groups had a significantly greater %ΔBDV (approximately 2- and 1.89-fold) at 3-months post-surgery, respectively (p < 0.05). However, at the 6- and 12- month follow-up, the %ΔBDV was not significantly different between the groups. CONCLUSION: These data suggest acemannan enhanced early bone healing after apical surgery.

Ameloblastic Carcinoma in a 2-Year-Old Child: A Case Report and Review of the Literature.

Ameloblastic carcinoma (AC) is a rare malignant odontogenic tumor in pediatric patients, only 22 cases have been reported in literature since 1932. We present an extremely rare case in which AC occurred in a 2-year-old girl, who had a tumor in the right mandible. Radiographic findings showed a multilocular, poorly defined, and mixed radiolucent-radiopaque lesion in the region of teeth #84 to #85, with bone and tooth root resorption. Computed tomography revealed buccal cortex destruction, tumor infiltration of soft tissue, and enlarged nodes. Incisional biopsy showed histomorphological features of AC. Immunohistochemical analysis exhibited a positive result for Cytokeratin (CK) 19 and overexpression of p53 and Ki67. The patient underwent right hemimandibulectomy and neck dissection. The final pathology was consistent with the initial diagnosis of AC. The patient did not exhibit signs of recurrence or metastasis within 2 years postoperatively. Given the rarity of this disease and the age of the patient, this report constitutes a valuable contribution to the current literature.

Acemannan Used as an Implantable Biomaterial for Vital Pulp Therapy of Immature Permanent Teeth Induced Continued Root Formation.

Direct pulp-capping, a vital pulp therapy, is used to protect and preserve pulp vitality by applying a biomaterial on the pulp exposure site. Acemannan, a polysaccharide extracted from Aloe vera, induces osteodentin-bridge formation to cover the exposure site in vivo. We evaluated the effect of acemannan sponges on partial pulpotomized permanent teeth with caries or accident-induced pulp exposure (n = 50). After removing infected dentin and inflamed pulp tissue, the teeth were randomly divided into acemannan or control (mineral trioxide aggregate (MTA) groups (n = 25). The teeth were examined immediately after treatment (baseline) and at 6- and 12-month follow-ups for clinical and cone beam computed tomography (CBCT) examination. The three-dimensional tooth length and root apex area were simulated to determine treatment success. We found that the overall success rate in the acemannan and MTA groups from baseline to 12-month follow-up was 90.91% and 95.65%, respectively, with no significant difference between the two groups (p > 0.05). In the success teeth in both groups, the root length increased, and the apex area significantly decreased (p < 0.05), indicating continued root formation. Our results suggest that acemannan is a promising low-cost biomaterial for partial pulpotomy treatment for immature permanent teeth requiring vital pulp therapy.

Acemannan Induced Bone Regeneration in Lateral Sinus Augmentation Based on Cone Beam Computed Tomographic and Histopathological Evaluation.

Acemannan, the major polysaccharide extracted from Aloe vera, is biomaterial that has demonstrated osteoinductive effects in vitro and in vivo. However, the effect of acemannan sponges on bone formation in open-type sinus augmentation has not evaluated. Here, we report a case study using radiographic and histological analyses to investigate the effect of acemannan on bone formation after lateral sinus lift surgery. The case was a 57-year-old female patient with an atrophic left posterior maxilla who underwent lateral sinus lift using an acemannan sponge using the two-stage procedure. In the first stage, an acemannan sponge was inserted through the bony window and placed between the antral floor and the elevated sinus membrane. Cone beam computed tomography (CBCT) images were taken immediately as baseline and 6-month postoperation for evaluation. A bone core specimen was also obtained for histological examination at the time of implant placement. The histological results revealed new bone formation, and the CBCT images demonstrated increased alveolar bone height at 6-month postoperation. Our findings suggest that an acemannan sponge could be a biomaterial for inducing bone formation in sinus lift surgery.

Corrosion Resistance of Graphene oxide/Silver Coatings on Ni-Ti alloy and Expression of IL-6 and IL-8 in Human Oral Fibroblasts.

Graphene based materials (GBMs) have potentials for dental and medical applications. GBMs may cause changes in the levels of cytokine released in the body. This study aimed to study the corrosion resistance of graphene oxide (GO) and GO/silver (GO/Ag) nanocomposite coated nickel-titanium (NiTi) alloy by electrophoretic deposition and to access the viability of human pulp fibroblasts, and the interleukin (IL)-6 and IL-8 expression level. The bare and coated NiTi samples were characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), Raman spectroscopy, surface profilometry, and X-ray diffraction (XRD). The corrosion resistance of the bare NiTi and coated NiTi samples were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy in 3.5% NaCl solution. The cell viability of human pulp fibroblasts was accessed by the treated culture medium of the bare NiTi and coated NiTi alloys containing 1% fetal bovine serum. IL-6 and IL-8 expression levels were studied by human enzyme-linked immunosorbent assay (ELISA). Data were analyzed using One-way ANOVA (α  =  0.05). Both the GO-coated NiTi and GO/Ag-coated NiTi alloys showed better corrosion resistance, a lower rate of corrosion, and higher protection efficiency than the bare NiTi alloy. The coated NiTi alloys were biocompatible to human pulp fibroblasts and showed upregulation of IL-6 and IL-8 levels.

Topical Proretinal Nanoparticles: Biological Activities, Epidermal Proliferation and Differentiation, Follicular Penetration, and Skin Tolerability.

Proretinal nanoparticles, the retinilidene-chitosan nanoparticles, have been developed to overcome the physicochemical instability of retinal and to lessen the dose-dependent cutaneous irritation, through sustaining the release of retinoid. Compared to conventional retinal at the same concentration, proretinal nanoparticles had no cytotoxicity and could induce a spontaneously immortalized human keratinocyte line to express more cellular retinoic acid binding protein-2. Compared to rats topically applied with conventional retinal which showed clear skin irritation and inflammation, daily topical application of proretinal nanoparticles to rats for 28 consecutive days produced neither irritation nor inflammation but significantly increased epidermal proliferation, epidermal thickness, cellular retinoic acid binding protein- 2 expression, and up-regulation of various differentiation markers including keratin 5, keratin 10, keratin 14, cellular retinoic acid binding protein-2, and proliferating cell nuclear antigen. Through the use of confocal laser scanning microscopy, we observed the in vivo follicular penetration of proretinal nanoparticles with the depth of penetration independent of postapplication time. Proretinal nanoparticles provide better biological activities of retinoids on epidermis and could eliminate the side effect of retinoid dermatitis.

Indirect Sinus Augmentation With and Without the Addition of a Biomaterial: A Randomized Controlled Clinical Trial.

PURPOSE: The aim of this study was to compare the results of indirect sinus augmentation with and without the addition of a biomaterial. MATERIALS AND METHODS: Thirty patients aged 40 to 60 years participated in this randomized controlled clinical trial. After closed sinus lift operation, patients were randomly and equally divided into blood clot control and acemannan sponge graft groups. Simultaneous implant placement was then performed. Cone beam computed tomography was performed immediately and at 3 and 6 months postoperation. Bone formation was evaluated by the radiographic endo-sinus bone gain percentage around the implant. RESULTS: Compared with the control group, the acemannan-treated group had a significantly greater radiographic endo-sinus bone gain percentage of approximately 2.4- and 2-fold at 3 and 6 months postsurgery, respectively (P < 0.05). CONCLUSION: The addition of a biomaterial (Acemannan) with indirect sinus augmentation and simultaneous implant placement significantly enhances bone formation at 3 and 6 months postsurgery.

Collagen and mPCL-TCP scaffolds induced differential bone regeneration in ovary-intact and ovariectomized rats.

BACKGROUND: The data on biomaterial-mediated bone regeneration directly comparing commercially available scaffolds in aging and osteoporotic conditions remain sparse. OBJECTIVE: To investigate the effects of an absorbable collagen sponge (ACS) and a medical grade polycaprolactone-tricalcium phosphate (mPCL-TCP) scaffold on calvarial defect healing in ovary-intact and ovariectomized rats. METHODS: Forty-two, 5-month old female Sprague-Dawley rats were divided into sham (OVI) or ovariectomy (OVX) groups (n=21). When rats reached 6 months old, 7 mm diameter calvarial defects were created and treated, further dividing each group into blood clot control, mPCL-TCP, or ACS subgroups (n=7). After four weeks, the calvarial specimens were evaluated using micro-computed tomography for bone volume fraction (BVF), and histopathology. RESULTS: The effects of ovariectomy were confirmed by changes in body, uterine, and vaginal weight, and osteopenia in the femur. A significant increase in BVF was observed in ACS-subgroups compared with their respective control groups (p<0.05). Histopathological analysis revealed no cellular inflammatory infiltrate in any group. Fibrous tissue encapsulated the mPCL-TCP, while the ACS was well-integrated with the bone matrix. The OVX groups presented more osteoid and enlarged marrow cavities compared with the OVI groups. CONCLUSION: ACS scaffold enhanced calvarial bone regeneration in OVI and OVX rats after four weeks.

Acemannan increased bone surface, bone volume, and bone density in a calvarial defect model in skeletally-mature rats.

BACKGROUND/PURPOSE: Acemannan, a ß-(1-4)-acetylated polymannose extracted from Aloe vera gel, has been proposed as biomaterial for bone regeneration. The aim of this study was to investigate the effect of acemannan in calvarial defect healing. MATERIALS AND METHODS: Acemannan was processed to freeze-dried sponge form and disinfected by UV irradiation. Thirty-five female Sprague-Dawley rats were used in the in vivo study. Seven-mm diameter mid-calvarial defects were created and randomly allocated into blood clot control (C), acemannan 1 mg (A1), 2 mg (A2), 4 mg (A4), and 8 mg (A8) groups (n = 7). After four weeks, the calvarial specimens were subjected to microcomputed tomography (microCT) and histopathological analysis. RESULTS: MicroCT revealed a significant increase in bone surface and bone volume in the A1 and A2 groups, and tissue mineral density in the A4 and A8 groups compared with the control group (p < 0.05). Histologically, the acemannan-treated groups had denser bone matrix compared with the control group. CONCLUSION: Acemannan is an effective bioactive agent for bone regeneration, enhancing bone growth as assayed in two- and three-dimensions.

Stimulation of Dentin Regeneration by Using Acemannan in Teeth with Lipopolysaccharide-induced Pulp Inflammation.

INTRODUCTION: This study investigated the effects of acemannan, a polysaccharide from Aloe vera, on human deciduous pulp cells in vitro and the response after vital pulp therapy in dog deciduous teeth. METHODS: Human primary dental pulpal cells were treated with acemannan in vitro and evaluated for proliferation, alkaline phosphatase activity, type I collagen, bone morphogenetic protein (BMP-2), BMP-4, vascular endothelial growth factor, and dentin sialoprotein expression and mineralization. Osteogenesis-related gene expression was analyzed by complementary DNA microarray. Pulpal inflammation was induced in dog teeth for 14 days. The inflamed pulp was removed, retaining the healthy pulp. The teeth were randomly divided into 3 treatment groups: acemannan, mineral trioxide aggregate, and formocresol. Sixty days later, the teeth were extracted and evaluated histopathologically. RESULTS: Acemannan significantly increased pulp cell proliferation, alkaline phosphatase, type I collagen, BMP-2, BMP-4, vascular endothelial growth factor, and dentin sialoprotein expression and mineralization approximately 1.4-, 1.6-, 1.6-, 5.5-, 2.6-, 3.8-, 1.8-, and 4.8-fold, respectively, compared with control. In vivo, partial pulpotomy treatment using acemannan generated outcomes similar to mineral trioxide aggregate treatment, resulting in mineralized bridge formation with normal pulp tissue without inflammation or pulp necrosis. In contrast, the formocresol group demonstrated pulp inflammation without mineralized bridge formation. CONCLUSIONS: Acemannan is biocompatible with the dental pulp. Furthermore, acemannan stimulated dentin regeneration in teeth with reversible pulpitis.

Acemannan increases NF-κB/DNA binding and IL-6/-8 expression by selectively binding Toll-like receptor-5 in human gingival fibroblasts.

Acemannan, an acetylated polymannose from Aloe vera, has immunomodulatory effects. We investigated whether acemannan induces IL-6 and -8 expression and NF-κB/DNA binding in human gingival fibroblasts. IL-6 and -8 expression levels were assessed via RT-PCR and ELISA. The NF-κB p50/p65-DNA binding was determined. The structures of acemannan mono-pentamers and Toll-like receptor 5 (TLR5) were simulated. The binding energies between acemannan and TLR5 were identified. We found that acemannan significantly stimulated IL-6/-8 expression at both the mRNA and protein level and significantly increased p50/DNA binding. Preincubation with an anti-TLR5 neutralizing antibody abolished acemannan-induced IL-6/-8 expression and p50/DNA binding, and co-incubation of acemannan with Bay11-7082, a specific NF- κB inhibitor, abolished IL-6/-8 expression. The computer modeling indicated that monomeric/dimeric single stranded acemannan molecules interacted with the TLR5 flagellin recognition sites with a high binding affinity. We conclude that acemannan induces IL-6/-8 expression, and p50/DNA binding in gingival fibroblasts, at least partly, via a TLR5/NF-κB-dependent signaling pathway. Furthermore, acemannan selectively binds with TLR5 ectodomain flagellin recognition sites.

Clinical, radiographic, and histologic analysis of the effects of acemannan used in direct pulp capping of human primary teeth: short-term outcomes.

Acemannan has been previously reported as a direct pulp-capping agent in animal study. This natural material demonstrated its biocompatibility and enhanced reparative dentin formation. The objective of this study was to investigate the action of acemannan as a direct pulp-capping material in human primary teeth with deep caries. Forty-two deeply carious mandibular primary molars from 37 children, aged 7-11 years old diagnosed with reversible pulpitis were studied. After completely removing the infected dentine, teeth with a pinpoint pulpal exposure were randomly divided into two treatment groups: acemannan or calcium hydroxide. A glass-ionomer cement base was applied to all teeth prior to restoration with stainless steel crowns. Clinical and radiographic evaluation was performed 6 months post-treatment. The teeth due to exfoliate were extracted and histopathologically evaluated for inflammation, dentine bridge formation, and soft tissue organization. At 6 months, the overall clinical and radiographic success rates of direct pulp capping with acemannan and calcium hydroxide at 6 months were 72.73 and 70.0 %, respectively. The histopathological results indicated that the acemannan-treated group had significantly better histopathological responses compared with the calcium hydroxide-treated group (p < 0.05). These data suggest acemannan offers a valuable alternative biomaterial for vital pulp therapy in primary teeth.

Deacetylation affects the physical properties and bioactivity of acemannan, an extracted polysaccharide from Aloe vera.

Acemannan, an acetylated polymannose from Aloe vera, induces tissue repair. We investigated the role of acemannan's acetyl-groups on its physical and biological properties. Deacetylated acemannan (DeAcAM) was prepared and characterized. The physical properties and microscopic structure of DeAcAM were evaluated using water solubility, contact angle, X-ray diffraction, and scanning-electron microscopy. The activity of DeAcAM on cell proliferation and gene expression were assessed. Acemannan and DeAcAM structures were simulated and the acemannan tetramer diad and its completely deacetylated structure were also determined. Increased acemannan deacetylation reduced its water solubility and hydrophilicity. Complete deacetylation altered acemannan's conformation to a partial crystal structure. The bioactivity of acemannan was reduced corresponding to its deacetylation. Acemannan induced cell proliferation, and VEGF and Collagen I expression; however, 100% DeAcAM did not. The simulated structures of the acemannan diad and the completely deacetylated diad were different. We conclude acetyl-groups affect acemannan's structure and physical/biological properties.