Evaluation of alveolar ridge preservation in sockets with buccal dehiscence defects using two types of xenogeneic biomaterials: An in vivo experimental study.

OBJECTIVES: Alveolar ridge preservation (ARP) has been extensively investigated in various preclinical and clinical studies, yielding favorable results. We aim to evaluate the effects of ARP using collagenated bovine bone mineral (CBBM) alone or particulated bovine bone mineral with a non-cross-linked collagen membrane (PBBM/NCLM) in tooth extraction sockets with buccal dehiscence in an experimental dog model. MATERIALS AND METHODS: The mesial roots of three mandibular premolars (P2, P3, and P4) were extracted from six mongrel dogs 4 weeks after inducing dehiscence defects. ARP was randomly performed using two different protocols: 1) CBBM alone and 2) PBBM/NCLM. Three-dimensional (3D) volumetric, micro-computed tomography, and histological analyses were employed to determine changes over a span of 20 weeks. RESULTS: In 3D volumetric and radiographic analyses, CBBM alone demonstrated similar effectiveness to PBBM/NCLM in ARP (p > .05). However, in the PBBM/NCLM group (3.05 ± 0.60 mm), the horizontal ridge width was well maintained 3 mm below the alveolar crest compared with the CBBM group (2.11 ± 1.01 mm, p = .002). CONCLUSION: Although the radiographic changes in the quality and quantity of bone were not significant between the two groups, the use of PBBM/NCLM resulted in greater horizontal dimensions and more favorable maintenance of the ridge profile.

Oral Microbiome Using Colocasia antiquorum var. esculenta Extract Varnish in a Mouse Model with Oral Gavage of P. gingivalis ATCC 53978.

Background and Objective: There is increasing interest in preventing periodontitis using natural products. The purpose of this study was to investigate the effect of Colocasia antiquorum var. esculenta (CA) varnish on the oral microbiome and alveolar bone loss in a mouse periodontitis model. Materials and Methods: Antibacterial activity against Porphyromonas gingivalis (P. gingivalis) ATCC 53978 and cell cytotoxicity using CCK-8 on L929 cells were measured. Balb/c mice were assigned into five groups (negative control, positive control, CA in drinking water, varnish, and CA varnish). P. gingivalis was administered to the mice by oral gavage three times. After sacrifice, the oral microbiome and the levels of the inflammatory cytokine IL-1ß and matrix metalloproteinase-9 were analyzed. Alveolar bone loss was measured using micro-computed tomography. Results: CA extract showed an antibacterial effect against P. gingivalis (p < 0.05) and showed no cytotoxicity at that concentration (p > 0.05). Although alpha diversity of the oral microbiome did not statistically differ between the groups (p > 0.05), the relative abundance of dominant bacteria tended to be different between the groups. The inflammatory cytokine IL-1ß was reduced in the CA varnish group (p < 0.05), and no difference was observed in MMP-9 expression and alveolar bone loss (p > 0.05). Conclusions: CA varnish did not affect the overall microflora and exhibited an anti-inflammatory effect, suggesting that it is possibility a suitable candidate for improving periodontitis.

Effects of Colocasia antiquorum var. Esculenta Extract In Vitro and In Vivo against Periodontal Disease.

Background and Objectives: Periodontal disease is a chronic inflammatory disease in which gradual destruction of tissues around teeth is caused by plaque formed by pathogenic bacteria. The purpose of this study was to evaluate the potential of 75% ethanol extract of Colocasia antiquorum var. esculenta (CA) as a prophylactic and improvement agent for periodontal disease in vitro and in vivo. Materials and Methods: The antimicrobial efficacy of CA against Porphyromonas gingivalis (P. gingivalis, ATCC 33277) was evaluated using minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) test, and cytotoxicity was confirmed by CCK-8 assay. For the in vivo study, P. gingivalis was applied by oral gavage to BALB/c mice. Forty-two days after the first inoculation of P. gingivalis, intraoral swabs were taken for microbiome analysis, and the mice were sacrificed to evaluate the alveolar bone loss. Results: The MIC of CA against P. gingivalis was 31.3 µg/mL, the MBC was 62.5 µg/mL, with no cytotoxicity. The diversity of the oral microbiome decreased in the positive control group, while those of the VA (varnish) and VCA (varnish added with CA) groups increased as much as in the negative control group, although the alveolar bone loss was not induced in the mouse model. Conclusions: CA showed antibacterial effects in vitro, and the VA and VCA groups exhibited increased diversity in the oral microbiome, suggesting that CA has potential for improving periodontal disease.

Inhibitory Effect of Asplenium incisum on Bacterial Growth, Inflammation, and Osteoclastogenesis.

Background and Objectives:Asplenium incisum, a natural plant, is known to possess numerous pharmacological and biochemical properties. However, the inhibitory effect of A. incisum against Porphyromonas gingivalis and other factors related to periodontal disease have not yet been demonstrated. This study aimed to investigate the potential of A. incisum extract as a phytotherapeutic candidate for improving periodontal diseases by assessing its antibacterial, anti-inflammatory, and anti-osteoclastogenic activities. Materials and Methods: The inhibition of proliferation of P. gingivalis by A. incisum and the sustainability of its antibacterial activity were evaluated in this study. The production of inflammatory cytokines (tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)) and nitric oxide (NO) from lipopolysaccharide-stimulated RAW 264.7 cells was assessed using an enzyme-linked immunosorbent assay. To identify the anti-osteoclastogenic activity, tartrate-resistant acid phosphatase (TRAP) staining and TRAP activity analyses were performed on bone marrow macrophages. Results: The proliferation of P. gingivalis was significantly inhibited by A. incisum (p < 0.001), and the antibacterial activity was sustained for up to 3 days. A. incisum showed anti-inflammatory activities by significantly decreasing the release of TNF-α, IL-6 (p < 0.05), and NO (p < 0.01). In addition, A. incisum significantly suppressed TRAP-positive cells and TRAP activity (at 30 µg/mL, p < 0.01) without causing any cytotoxicity (p > 0.05). Conclusions:A. incisum showed antibacterial, anti-inflammatory, and anti-osteoclastogenic activities, suggesting it has strong therapeutic potential against periodontal diseases.

Reinforcing effect of glass-fiber mesh on complete dentures in a test model with a simulated oral mucosa.

STATEMENT OF PROBLEM: Studies that evaluated the strength of complete dentures reinforced with glass-fiber mesh or metal mesh on a cast with a simulated oral mucosa are lacking. PURPOSE: The purpose of this in vitro study was to compare the mechanical properties of maxillary complete dentures reinforced with glass-fiber mesh with those of metal mesh in a new test model, using a simulated oral mucosa. MATERIAL AND METHODS: Complete dentures reinforced with 2 types of glass-fiber mesh, SES mesh (SES) and glass cloth (GC) and metal mesh (metal) were fabricated. Complete dentures without any reinforcement were prepared as a control (n=10). The complete dentures were located on a cast with a simulated oral mucosa, and a load was applied on the posterior artificial teeth bilaterally. The fracture load, elastic modulus, and toughness of a complete denture were measured using a universal testing machine at a crosshead speed of 5 mm/min. The fracture load and elastic modulus were analyzed using 1-way analysis of variance, and the toughness was analyzed with the Kruskal-Wallis test (α=.05). The Tukey multiple range test was used as a post hoc test. RESULTS: The fracture load and toughness of the SES group was significantly higher than that of the metal and control groups (P<.05) but not significantly different from that of the GC group. The elastic modulus of the metal group was significantly higher than that of the control group (P<.05), and no significant differences were observed in the SES and GC groups. CONCLUSIONS: Compared with the control group, the fracture load and toughness of the SES and GC groups were higher, while those of the metal group were not significantly different.

A microfluidic cell culture device (µFCCD) to culture epithelial cells with physiological and morphological properties that mimic those of the human intestine.

Physiological and morphological properties of the human intestine cannot be accurately mimicked in conventional culture devices such as well plates and petri dishes where intestinal epithelial cells form a monolayer with loose contacts among cells. Here, we report a novel microfluidic cell culture device (µFCCD) that can be used to culture cells as a human intestinal model. This device enables intestinal epithelial cells (Caco-2) to grow three-dimensionally on a porous membrane coated with fibronectin between two polydimethylsiloxane (PDMS) layers. Within 3 days, Caco-2 cells cultured in the µFCCD formed villi- and crypt-like structures with small intercellular spaces, while individual cells were tightly connected to one another through the expression of the tight junction protein occludin, and were covered with a secreted mucin, MUC-2. Caco-2 cells cultured in the µFCCD for 3 days were less susceptible to bacterial attack than those cultured in transwell plates for 21 days. µFCCD-cultured Caco-2 cells also displayed physiologically relevant absorption and paracellular transport properties. These results suggest that our intestinal model more accurately mimics the morphological and physiological properties of the intestine in vivo than the conventional transwell culture model.

Effects of glass fiber mesh with different fiber content and structures on the compressive properties of complete dentures.

STATEMENT OF PROBLEM: No study has yet evaluated the strength of complete dentures reinforced with glass fiber meshes with different content and structures. PURPOSE: The purpose of this study was to compare the reinforcing effects of glass fiber mesh with different content and structures with that of metal mesh in complete dentures. MATERIAL AND METHODS: Two types of glass fiber mesh were used: SES mesh (SES) and glass cloth (GC2, GC3, and GC4). A metal mesh was used for comparison. The complete dentures were made by placing the reinforcement 1 mm away from the tissue surface. A control group was prepared without any reinforcement (n=10). The compressive properties were measured by a universal testing machine at a crosshead speed of 5 mm/min. The results were analyzed with the Kruskal-Wallis test and the Duncan multiple range test (α=.05). RESULTS: The fracture resistance of the SES group was significantly higher than that of the control, GC4, and metal groups (asymptotic P=.004), but not significantly different from the GC2 and GC3 groups. The toughness of the SES and GC3 groups was significantly higher than that of the others (asymptotic P<.001), but not significantly different from that of the GC4 group. CONCLUSIONS: SES and GC3, which have different structures but similar volume content, were the most effective in reinforcing complete dentures. The content of the glass fiber mesh seemed more important than the structures.

Antibacterial activities of phytochemicals against Porphyromonas gingivalis with and without experimental fluoride varnish for periodontal disease prevention.

We aimed to evaluate the antibacterial activity of phytochemicals with or without an experimental fluoride varnish against Porphyromonas gingivalis. Five phytochemicals, chrysophanol (CHR), emodin (EMO), anthrarufin (ANT), bavachalcone (BCC), and isobavachromene (IBC), were tested using agar diffusion, minimal inhibition concentration (MIC), and minimum bacterial concentration (MBC) assays. We also assessed the cell viability and cytotoxicity of phytochemicals. All phytochemicals showed clear inhibition zones in the agar diffusion test. The inhibition zones of all phytochemical-containing fluoride varnishes were similar to or larger than that of the positive control, excluding that of 1 mM EMO. With or without the fluoride varnish, BCC exhibited the lowest MIC and MBC levels. Cell viability was high in the presence of all phytochemicals except 200 µM EMO. In conclusion, BCC was most effective as a phytochemical alone, while all phytochemical-containing fluoride varnishes inhibited P. gingivalis growth without cytotoxicity.

Effectiveness of a collagen matrix seal and xenograft in alveolar ridge preservation: an experimental study in dogs.

Majority of previous studies on alveolar ridge preservation (ARP) used collagen membranes as barrier membranes, and further evidence for ARP in dehiscent extraction sockets with a deproteinized bovine bone mineral (DBBM) and matrix is needed. The aim of this study is to assess the impact of non-cross linked collagen membranes (membrane) and crosslinked collagen matrices (matrix) on ARP using DBBM in extraction sockets with buccal dehiscence. In six mongrel dogs, the mesial roots of three mandibular premolars (P2, P3, and P4) were extracted 1 month after dehiscence defect induction. Two experimental groups were randomly assigned: (1) DBBM with a membrane (DBBM/membrane group) and (2) DBBM with a matrix (DBBM/matrix group). Three-dimensional (3D) volumetric, microcomputed tomography (µCT), and histologic analyses were performed to assess the ridge preservation. Both groups were effective to maintain the ridge width (p > 0.05), and the DBBM/matrix group showed more favorable soft tissue regeneration and bone quality in the histological analysis (p = 0.05). Based on these results, DBBM/matrix could be better choice for ARP in cases of buccal dehiscence defects.

Effect of adhesive components in experimental fluoride varnish on fluoride release within 30 days in vitro study.

We aimed to determine whether adhesive components could increase the release time of effective fluoride concentration from an experimental fluoride varnish applied to bovine teeth. An experimental fluoride varnish containing 5% sodium fluoride (EX1) was prepared and combined with 35% hydroxyethyl methacrylate (HEMA) (EX2), 5% glutaraldehyde (EX3), or 35% HEMA/5% glutaraldehyde mixture (EX4). Two commercially available fluoride varnishes were used for comparison. Each group was applied to bovine incisors, and the fluoride release and pH were monitored for 30 days. Cell viability analysis, scanning electron microscopy, and energy-dispersive spectroscopy were performed. EX4 released the highest and most effective concentration of fluoride for the longest period and reached neutral pH at the earliest; the release was maintained for up to 30 days without cytotoxicity. In conclusion, EX4 is considered to be the most effective varnish to prevent dental caries.

Molecular and immunohistochemical characterization of the chitinase gene from Pieris rapae granulovirus.

The chitinase gene of baculoviruses is expressed in the late phase of virus replication in insects and possesses high exo- and endochitinase activity, which can hydrolyze chitin in the body of the insect, thus promoting terminal host liquefaction. Alphabaculovirus viral chitinases (vChitA) have been well analyzed, but information regarding viral chitinases from betabaculoviruses is limited. Whole-genome sequencing of a Korean isolate of Pieris rapae GV (PiraGV-K) predicted a putative chitinase gene corresponding to ORF10. The PiraGV-K chitinase gene had a coding sequence of 1,761 bp, encoding a protein of 586 amino acid (aa) residues, including an 18-aa putative signal peptide. Time course induction pattern observed by SDS-PAGE and subsequent Western blot with anti-PiraGV-K chitinase antibody revealed the cleavage of the signal peptide from the intact chitinase. Edman sequencing analysis was further conducted to confirm the exact nature of the mature chitinase, and the N-terminal amino acid sequence (KPGAP) exactly matched the sequence following the signal peptide sequence. The transcriptomics of PiraGV-K chitinase in infected P. rapae larvae, examined by real-time PCR, revealed a significant 75-fold increase after four days of feeding with PiraGV-K-treated leaves, with a subsequent decline at the later stages of infection. Confocal microscopic analysis showed that PiraGV-K chitinase possibly exists as a secreted protein, with strong chitinase-specific signals in fat body cells and integument at four days postinfection. Furthermore, immunogold labeling and electron microscopy studies localized the PiraGV-K chitinase in the cytoplasm and sparsely within vacuolar structures in the fat body apart from the extensive aggregation in the cuticular lining of the integument.

Molecular and immunohistochemical characterization of granulin gene encoded in Pieris rapae granulovirus genome.

Pieris rapae granulovirus (PiraGV) is highly pathogenic to the cabbage butterfly (P. rapae), an important pest of cultivated cabbages and mustard crops. It therefore holds significant promise towards exploitation as a potent bio-control agent in the field controlling the pest population. Whole-genome elucidation of the Korean isolate of the granulovirus (PiraGV-K), reported the presence of a granulin gene corresponding to ORF 1 in its genome. Comprehensive studies towards functional characterization of the gene, established that it is composed of 744 nucleotides and encodes a peptide of 247 amino acid residues. It possessed significant homology with AoGV and ClanGV with 87% identity at amino acid level. Multiple alignment data suggests that the C-terminus region of the gene had three different conserved regions. Time-course studies conducted in PiraGV-K infected P. rapae larvae revealed a significant upsurge of the transcript (134-fold) at 4 days post infection followed by a significant decline at the most advanced stages of infection. Anti-PiraGV-K granulin antibody was produced and western blot conducted with the infected larvae further confirmed the induction pattern with a protein of 30 kDa. Immunofluorescent staining showed a granulin-specific signal in fat body and integument of the infected larvae. Granulin-specific signals were noticed 2 days post infection with the eventual systemic spread of infection to the associated tracheal matrix witnessed at 4 days post infection. Immunogold labeling and electron microscopic studies further proved the cytopathological effects as the presence of numerous membrane-bound vesicles with nucleocapsids and abruption of intercellular junctions in fat body and hypertrophied cells in the integument.

Antibacterial Activity and Sustained Effectiveness of Calcium Silicate-Based Cement as a Root-End Filling Material against Enterococcus faecalis.

Several calcium silicate cement (CSC) types with improved handling properties have been developed lately for root-end filling applications. While sealing ability is important, a high biocompatibility and antimicrobial effects are critical. This study aimed to conduct a comparative evaluation of the antimicrobial efficacy and sustained antibacterial effectiveness against Enterococcus faecalis (E. faecalis) of commercially available CSCs mixed with distilled water (DW) and chlorhexidine (CHX). Various products, viz., ProRoot mixed with DW (PRW) or with CHX (PRC), Endocem mixed with DW (EW) or with CHX (EC), and Endocem premixed (EP) syringe type, were used. While antibacterial activity against E. faecalis was evaluated using a direct contact method, the specimens were stored in a shaking incubator for 30 d for antibacterial sustainability. The cytotoxicity was evaluated using a cell counting kit-8 assay in human periodontal ligament stem cells. The antibacterial activities of EP, EW, and EC were greater than those of PRC and PRW (p < 0.05). The antibacterial sustainability of EP was the highest without cytotoxicity for up to 30 days (p < 0.05). In conclusion, the pre-mixed injectable type EP was most effective in terms of antibacterial activity and sustained antibacterial effectiveness without cytotoxicity.

Photobiomodulation-Based Synergic Effects of Pt-Coated TiO2 Nanotubes and 850 nm Near-Infrared Irradiation on the Osseointegration Enhancement: In Vitro and In Vivo Evaluation.

Photobiomodulation (PBM) therapy is known to have the potential to improve bone regeneration after implant surgery. However, the combinatory effect of the nanotextured implant and PBM therapy on osseointegration has not yet been proved. This study evaluated the photobiomodulation-based synergistic effects of Pt-coated titania nanotubes (Pt-TiO2 NT) and 850 nm near-infrared (NIR) light on osteogenic performance in vitro and in vivo. The FE-SEM and the diffuse UV-Vis-NIR spectrophotometer were used to perform the surface characterization. The live-dead, MTT, ALP, and AR assays were tested to perform in vitro tests. The removal torque testing, the 3D-micro CT, and the histological analysis were used to conduct in vivo tests. The live-dead and MTT assay resulted in Pt-TiO2 NTs being biocompatible. The ALP activity and AR assays demonstrated that the combination of Pt-TiO2 NT and NIR irradiation significantly enhanced osteogenic functionality (p < 0.05). The results of in vivo test, employing the removal torque testing, the 3D-micro CT, and histological analysis, showed overall improved outcomes; however, no significant difference was observed between the control and experimental groups (p > 0.05). Therefore, we confirmed the possibility of the combination of Pt-TiO2 NT and NIR light as a promising technology for implant surgery in dentistry.

Gingival biotype modification with collagen matrix or autogenous subepithelial connective tissue graft: Histologic and volumetric analyses in a beagle model.

Objectives: To evaluate the volumetric effect and biocompatibility of porcine tendon-derived type I collagen matrix graft (CG) in gingival biotype modification (GBM) compared with subepithelial connective tissue graft (SCTG) in a beagle model. Methods: Surface analysis using scanning electron microscopy and a collagen degradation assay of CG was performed in vitro. Six adult dogs were used in in vivo experiment, and each received autologous SCTG or CG at the anterior side. Histometric and three-dimensional digital volume analyses were conducted to compare quantitative changes in CG and SCTG in GBM. Immunohistochemical analysis was performed for the qualitative evaluation of CG compared to SCTG. Results: CG had a double-layered structure, and its degradation was slower than that of other well-reported materials. No critical problems were associated with the healing procedure. Changes in gingival thickness and volume in the CG and SCTG groups were equivalent, with no significant differences between the groups. Type I collagen and vascular endothelial growth factor expression levels were similar in both groups. Significance: CG and SCTG had equivalent potential for GBM in terms of quantity and quality. Additionally, CG could be used as a reasonable substitute for SCTG, making surgery convenient and predicting successful clinical outcomes.

Evaluation of the machinability and machining accuracy of polymer-based CAD/CAM blocks using merlon fracture test model.

The aims of this study were to estimate the machinability and machining accuracy of polymer-based CAM blocks using the merlon fracture test model specified in ISO 18675: 2022. Three hybrid disc blanks (MazicDuro, HC Disk, and Enamic) and three polymethyl methacrylate (PMMA) disc blanks (PMMA Disk, PMMA Block, and MazicTemp Hybrid) were tested in this study. The machinability was evaluated by assigning scores according to the fracture range of merlons with areas divided by ten vertical planes. The machining accuracy was evaluated by superimposing methods via CAD reference data and CAD specimen data. Within the limits of this study, a thickness of 0.3 mm is recommended for the clinical application of polymer-based CAD/CAM blocks in dental restorations that require superior machinability and accuracy. In addition, the machinability and machining accuracy tests of polymer-based CAM blocks are expected to provide guidelines for preparing accurate dental restorations.

Enhanced Bone Formation by Rapidly Formed Bony Wall over the Bone Defect Using Dual Growth Factors.

BACKGROUND: In guided bone regeneration (GBR), there are various problems that occur in the bone defect after the wound healing period. This study aimed to investigate the enhancement of the osteogenic ability of the dual scaffold complex and identify the appropriate concentration of growth factors (GF) for new bone formation based on the novel GBR concept that is applying rapid bone forming GFs to the membrane outside of the bone defect. METHODS: Four bone defects with a diameter of 8 mm were formed in the calvaria of New Zealand white rabbits each to perform GBR. Collagen membrane and biphasic calcium phosphate (BCP) were applied to the bone defects with the four different concetration of BMP-2 or FGF-2. After 2, 4, and 8 weeks of healing, histological, histomorphometric, and immunohistochemical analyses were conducted. RESULTS: In the histological analysis, continuous forms of new bones were observed in the upper part of bone defect in the experimental groups, whereas no continuous forms were observed in the control group. In the histomorphometry, The group to which BMP-2 0.5 mg/ml and FGF-2 1.0 mg/ml was applied showed statistically significantly higher new bone formation. Also, the new bone formation according to the healing period was statistically significantly higher at 8 weeks than at 2, 4 weeks. CONCLUSION: The novel GBR method in which BMP-2, newly proposed in this study, is applied to the membrane is effective for bone regeneration. In addition, the dual scaffold complex is quantitatively and qualitatively advantageous for bone regeneration and bone maintenance over time.

Improving Bone Formation by Guided Bone Regeneration Using a Collagen Membrane with rhBMP-2: A Novel Concept.

We examined whether recombinant human bone morphogenetic protein-2 (rhBMP-2) when applied to collagen membranes, would reinforce them during guided bone regeneration. Four critical cranial bone defects were created and treated in 30 New Zealand white rabbits, including a control group, critical defect only; group 1, collagen membrane only; group 2, biphasic calcium phosphate (BCP) only; group 3, collagen membrane + BCP; group 4, collagen membrane with rhBMP-2 (1.0 mg/mL); group 5, collagen membrane with rhBMP-2 (0.5 mg/mL); group 6, collagen membrane with rhBMP-2 (1.0 mg/mL) + BCP; and group 7, collagen membrane with rhBMP-2 (0.5 mg/mL) + BCP. After a 2-, 4-, or 8-week healing period, the animals were sacrificed. The combination of collagen membranes with rhBMP-2 and BCP yielded significantly higher bone formation rates compared to the other groups (control group and groups 1-5 < groups 6 and 7; p < 0.05). A 2-week healing period yielded significantly lower bone formation than that at 4 and 8 weeks (2 < 4 = 8 weeks; p < 0.05). This study proposes a novel GBR concept in which rhBMP-2 is applied to collagen membranes outside instead of inside the grafted area, thereby inducing quantitatively and qualitatively enhanced bone regeneration in critical bone defects.

Stem cell fate dictated solely by altered nanotube dimension.

Two important goals in stem cell research are to control the cell proliferation without differentiation and to direct the differentiation into a specific cell lineage when desired. Here, we demonstrate such paths by controlling only the nanotopography of culture substrates. Altering the dimensions of nanotubular-shaped titanium oxide surface structures independently allowed either augmented human mesenchymal stem cell (hMSC) adhesion or a specific differentiation of hMSCs into osteoblasts by using only the geometric cues, absent of osteogenic inducing media. hMSC behavior in response to defined nanotube sizes revealed a very dramatic change in hMSC behavior in a relatively narrow range of nanotube dimensions. Small (approximately 30-nm diameter) nanotubes promoted adhesion without noticeable differentiation, whereas larger (approximately 70- to 100-nm diameter) nanotubes elicited a dramatic stem cell elongation (approximately 10-fold increased), which induced cytoskeletal stress and selective differentiation into osteoblast-like cells, offering a promising nanotechnology-based route for unique orthopedics-related hMSC treatments.

Shear bond strengths of various resin cements between three types of adherends and bovine teeth with and without thermocycling.

This study evaluated the shear bond strengths of various types of resin cements between three types of adherends (composite resin, metal, and ceramic) and bovine teeth with and without thermocycling. A conventional resin cement (Variolink N), two adhesive resin cements (PANAVIA F 2.0, Multilink N), and three self-adhesive resin cements (MAXCEM ELITE, Rely X Unicem 2, Speed CEM) were used. The adherends were cemented on the superficial dentin of bovine incisors using each resin cement. Herein, 10 specimens from each group were thermocycled 5,000 times, and the other 10 were stored without thermocycling. With the resin and ceramic adherends, the shear bond strengths of Rely X Unicem 2 were significantly higher than those of the other resin cements both with and without thermocycling (p<0.05). With the metal adherend, the shear bond strengths were not significantly different among the cement groups, except MAXCEM ELITE, which showed the lowest strength.