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Camphorquinone (CQ) and resin monomers are included in dentin bonding agents (DBAs) and composite resin to restore tooth defects due to abrasion, crown fracture, or dental caries. DBAs, CQ, and bisphenol A-glycidyl methacrylate (BisGMA) applications influence the biological activities of the dental pulp. The current investigation aimed to delineate the effect of DBAs, CQ, and BisGMA on cathepsin L production/expression, lysosomal activity, and autophagy induction in human dental pulp cells (HDPCs). HDPCs were exposed to DBAs, CQ, or BisGMA with/without inhibitors for 24 h. Enzyme-linked immunosorbent assay was employed to determine the cathepsin L level in culture medium. The cell layer was utilized to measure cell viability by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl -tetrazolium bromide (MTT) assay. Real-time PCR was used to evaluate the mRNA expression. Western blotting or immunofluorescent staining was used to study protein expression. Lysosomal density was evaluated by lysotracker red staining. We found that DBAs, CQ, and BisGMA stimulated cathepsin L mRNA, protein expression, and production in HDPCs. In addition, CQ and BisGMA induced lysosomal activity, Beclin1, ATG12, LC3B, Bax, and p53 expression in HDPCs, indicating the stimulation of autophagy. Glutathione (GSH) prevented CQ- and BisGMA-induced cytotoxicity. Moreover, E64d, cathepsin L inhibitor (two cathepsin inhibitors), and Pifithrin-α (a p53 inhibitor) showed little preventive effect toward CQ- and BisGMA-induced cytotoxicity. Autophagy inhibitors (NH4Cl, Lys05) mildly enhanced the CQ- and BisGMA-induced cytotoxicity. These results indicate that DBAs stimulated cathepsin L, possibly due to their content of CQ and BisGMA that may induce cathepsin L in HDPCs. CQ and BisGMA stimulated lysosomal activity, autophagy, and apoptosis, possibly via induction of Beclin 1, ATG12, LC-3B, Bax, and p53 expression. In addition, CQ and BisGMA cytotoxicity was related to redox change and autophagy. These events are important role in pulpal changes after the restoration of tooth decay using CQ- and BisGMA-containing DBAs and resin composite.

The aim of the present study was to investigate the biomechanical behaviors of the pre-shaped titanium (PS-Ti) cranial mesh implants with different pore structures and thicknesses as well as the surface characteristics of the three-dimensional printed Ti (3DP-Ti) cranial mesh implant. The biomechanical behaviors of the PS-Ti cranial mesh implants with different pore structures (square, circular and triangular) and thicknesses (0.2, 0.6 and 1 mm) were simulated using finite element analysis. Surface properties of the 3DP-Ti cranial mesh implant were performed by means of scanning electron microscopy, X-ray diffraction and static contact angle goniometer. It was found that the stress distribution and peak Von Mises stress of the PS-Ti cranial mesh implants significantly decreased at the thickness of 1 mm. The PS-Ti mesh implant with the circular pore structure created a relatively lower Von Mises stress on the bone defect area as compared to the PS-Ti mesh implant with the triangular pore structure and square pore structure. Moreover, the spherical-like Ti particle structures were formed on the surface of the 3DP-Ti cranial mesh implant. The microstructure of the 3DP-Ti mesh implant was composed of α and rutile-TiO2 phases. For wettability evaluation, the 3DP-Ti cranial mesh implant possessed a good hydrophilicity surface. Therefore, the 3DP-Ti cranial mesh implant with the thickness of 1 mm and circular pore structure is a promising biomaterial for cranioplasty surgery applications.

The microstructure and surface properties of the optimal nanostructured-gold (ONG) film were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, nanoindentation and static contact angle evaluation in the present study. A three-dimensional model of human liver was reconstructed using magnetic resonance imaging to simulate the thermomechanical performance of the ONG film by means of finite element model analysis. Moreover, a monopolar electrosurgical unit equipped with needle type uncoated stainless steel (U-SS) and ONG film coated stainless steel (ONG-SS) electrodes was used to investigate the thermal distribution in the liver of rats. Experimental results showed that the temperature decreased significantly when using the ONG-SS electrode. The ONG-SS electrode also created a relatively small thermal injury area and lateral thermal effect. Furthermore, thermography indicated that the ONG-SS electrode exhibited a significantly lower surgical temperature as compared with the U-SS electrode during electrosurgery process in rats. Therefore, it could be demonstrated that the ONG-SS electrode is a promising biomedical device for reducing excessive thermal injury and decreasing adherence tissue in electrosurgery.

The present study established a maximum standard for printing quality and developed a preliminary ideal index to print three-dimensional (3D) construct using the Gly-Arg-Gly-Asp (GRGD) peptide modified Pluronic-F127 hydrogel (hereafter defined as 3DG bioformer (3BE)) as bioink. In addition, the biocompatibility of 3BE for 3D printing applications was carefully investigated. For biocompatibility study and ideal printing parameter, we used the formulation of 3BE in three different concentrations (3BE-1: 25%, 3BE-2: 30%, and 3BE-3: 35%). The 3BE hydrogels were printed layer by layer as a cube-like construct with all diameters of the needle head under the same feed (100 mm/s). The printing parameters were determined using combinations of 3BE-1, 3BE-2, and 3BE-3 with three different standard needle sizes (&Phi, 0.13 mm, &Phi, 0.33 mm, and &Phi, 0.9 mm). The printed constructs were photographed and observed using optical microscopy. The cell viability and proliferation were evaluated using Live/Dead assay and immunofluorescence staining. Results showed that a stable of printed line and construct could be generated from the 3BE-3 combinations. Cytotoxicity assay indicated that the 3BE hydrogels possessed well biocompatibility. Bioprinting results also demonstrated that significant cell proliferation in the 3BE-3 combinations was found within three days of printing. Therefore, the study discovered the potential printing parameters of 3BE as bioink to print a stable construct that may also have high biocompatibility for cell encapsulation. This finding could serve as valuable information in creating a functional scaffold for tissue engineering applications.

The objective of the present research was to investigate the thermal injury in the brain after minimally invasive electrosurgery using instruments with copper-doped diamond-like carbon (DLC-Cu) surface coating. The surface morphologies of DLC-Cu thin films were characterized using scanning electron microscopy and atomic force microscopy. Three-dimensional brain models were reconstructed using magnetic resonance imaging to simulate the electrosurgical operation. In adult rats, a monopolar electrosurgical instrument coated with the DLC-Cu thin film was used to generate lesions in the brain. Animals were sacrificed for evaluations on postoperative days 0, 2, 7, and 28. Data indicated that the temperature decreased significantly when minimally invasive electrosurgical instruments with nanostructure DLC-Cu thin films were used and continued to decrease with increasing film thickness. On the other hand, the DLC-Cu-treated device created a relatively small thermal injury area and lateral thermal effect in the brain tissues. These results indicated that the DLC-Cu thin film minimized excessive thermal injury and uniformly distributed the temperature in the brain. Taken together, our study results suggest that the DLC-Cu film on copper electrode substrates is an effective means for improving the performance of electrosurgical instruments.

Aim. Our goal was to investigate associations among scaling-stimulated changes in salivary antioxidants, oral-health-related behaviors and attitudes, and periodontal treatment outcomes.Materials and Methods. Thirty periodontitis patients with at least 6 pockets with pocket depths of >5 mm and more than 16 functional teeth were enrolled in the study. Patients were divided into three groups: an abandoned group (AB group), a nonprogress outcome group (NP group), and an effective treatment group (ET group). Nonstimulated saliva was collected before and after scaling were received to determine superoxide dismutase (SOD) and the total antioxidant capacity (TAOC).Results. Salivary SOD following scaling significantly increased from 83.09 to 194.30 U/g protein in patients who had irregular dental visit patterns (P<0.01). The scaling-stimulated increase in SOD was related to a higher severity of periodontitis in the NP group, while the scaling-stimulated increase in the TAOC was inversely related to the severity of periodontitis in the AB group.Conclusions. These results demonstrate the importance of scaling-stimulated salivary antioxidants as prognostic biomarkers of periodontal treatment.

This study fabricated hydrogenated diamond-like carbon/silver bioceramic films on glass substrates using radio frequency magnetron sputtering with a single silver target in an atmosphere of Ar/CH4 mixture. The effects of applied power on the composition and microstructure of bioceramic film were evaluated. A phase transformation, amorphous diamond-like carbon → nano-silver precipitation → nano-silver growth in the amorphous diamond-like carbon matrix was observed during sputtering. The film growth rate, surface roughness, silver content and size of silver nanoclusters in the films all increased with the silver target power due to the higher flux of sputtered silver species toward the substrate.

This study evaluated the phase transformation of calcium phosphate cement (CPC) using a mixture of monocalcium phosphate monohydrate (MCPM) and CaCO3 as the solid phase and either water or a sodium phosphate buffer (SPB) solution (pH=7.0) as the liquid phase. The synthetic CPC was characterized by X-ray diffraction (XRD) analysis and transmission electron microscopy (TEM). The setting reaction in the SPB solution involved three phase transformations. Firstly, MCPM and CaCO3 reacted with sodium phosphate immediately to form dicalcium phosphate dehydrate (DCPD) which continued to dissolve. Secondly, meanwhile, an intermediate amorphous calcium phosphate (ACP) was formed. Finally, ACP transformed into calcium-deficient hydroxyapatite (CDHA). In contrast, the reaction stopped at the first stage in water. Consequently, the SPB solution not only caused the dissolution of DCPD but also provided the buffering capacity to induce the conversion of the starting materials to CDHA.

Biodegradable calcium phosphate composites consisting of tricalcium phosphate (α-TCP) and hydroxyapatite (HA) were prepared using a two-step sintering method. The ratio of α-TCP/HA was controlled by modulating the sintering temperature. The initial calcination process at 800 °C causes HA dehydroxylation and induces the early transformation of HA into α-TCP in subsequent sintering processes. At the optimum sintering temperature of 1300 °C, the material is comprised of a moderate ratio of α-TCP to HA (3:7) and possesses a hardness of 5.0 GPa. The high temperature phase transformation from HA to α-TCP accompanied by bonded water loss, which results in the formation of nano-pores within the α-TCP matrix, hardly deteriorated the mechanical strength of the composite. This pore-containing structure also provided a convincing evidence for the origin of the high degradability of α-TCP in a biological environment.

Chronic rhinosinusitis (CRS) has raised attentions both in many countries due to its high relapsing rate and the resistance of certain treatments especially antibiotics application on both acute and chronic bacterial rhinosinusitis. The aim of this research is stressing on developing an effective alternative treatment for treating CRS and reducing the use of antibiotics to avoid further resistance forming. The antibacterial functions of silver nano-particles (AgNPs) are well known according to previous reports and studies. However, for developing a suitable treatment for further clinical application, a variety of AgNPs cell cytotoxicity experiments and AgNPs antibacterial properties experiments were examined in vitro in this study. For imitating the clinical condition of CRS, the human nasal epithelial cell line (RPMI2650) has chosen as experimental model. Moreover, Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) were selected for antibacterial function experiments. The analytical results demonstrated that 5 ppm of AgNPs not only maintains > 80% of cell activity to RPMI2650, but also possesses > 80% of antibacterial function to S. aureus and 100% of antibacterial function to E. coli. Therefore, 5 ppm of AgNPs might be considered as a promising antibacterial agent for treating CRS.

The objective of the present study was to investigate the thermal injury and tissue sticking in the liver after a minimally invasive electrosurgery with a chromium nitride (CrN) surface modifications. The surface morphologies and the hydrophobic properties of CrN thin films were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle goniometer. Three-dimensional (3D) liver models were reconstructed using magnetic resonance imaging to simulate the electrosurgical procedure. In animal model, needle type monopolar electrosurgery equipped with CrN thin films were used to create lesions in the liver of adult rats. Animals were sacrificed for evaluations at 0, 1, 2, and 4 weeks postoperatively. Data indicated that the temperature decreased significantly when minimally electrosurgery with nanostructured CrN thin films were used, and that it continued to decrease with increasing film thickness. In an animal model, thermography revealed that the surgical temperature was significantly lower in the minimally invasive electrosurgery with CrN thin film compared to untreated electrosurgery. In addition, adherence analysis showed that the smallest amount adherence tissue on the CrN electrode. Moreover, CrN electrosurgery created a relatively small thermal injury area and lateral thermal effect. The present study reveals that the novel nanostructured thin film on electrode substrates is an effective means of improving the performance of reducing excessive thermal injury, decreasing adherence tissue, and uniformly distributing temperature in the liver. However, further tests in the clinical trial must be evaluated to confirm the effect and safety of promising findings in the electrosurgery.

The purpose of this study was to investigate stresses resulting from different thicknesses of hydroxyapatite- and titanium dioxide (TiO2)-treated layers at the interface between temporomandibular joint (TMJ) implants and bones using three-dimensional finite element models. For ensuring osseointegration of implant treatment, one must examine the stresses of interface between implant and bone tissue. Treated layers on TMJ implants are a very important factor in clinical application. Several studies have investigated finite element models for TMJs, but few have examined a model for TMJ implants with treated layers. In this study, TMJ models were reconstructed using computer tomography data, and the effects of treated layer thickness on the stress field during jaw movement were investigated; this index has not yet been reported with respect to TMJ implant. The maximum stresses in the bone occurred at the position of the first screw. Data analysis indicated a greater decrease in this stress in the case of using TMJ implants with TiO2-treated layers, and the stresses decreased with increasing layer thicknesses. Results confirmed that the treated layers improve biomechanical properties of the TMJ implants and release abnormal stress concentration in them. The results of our study offer the potential clinical benefit of inducing superior biomechanical behavior in TMJ implants. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2013.

The interrelationship between periodontal and endodontic disease has aroused much speculation, confusion, and controversy. Pulpal and periodontal problems are responsible for more than 50% of tooth mortality today. Diagnosis is often difficult since these diseases have been studied primarily as separate entities. The toxic substances of the pulp may initiate periodontal defects through canal ramifications and patent dentinal tubules, thus impairing wound healing in regenerative procedures. Although no studies exist addressing the direct effect of pulpal infection on the outcome of guided tissue regeneration (GTR) procedures, several studies do indicate that pulpal status may play a significant role toward the end results of GTR. This review article discusses the potential influence of endodontic treatment on the long-term outcomes of GTR. Potential pathways between the pulp and periodontal ligament, which may be responsible for the failure of the regeneration of new periodontal attachment apparatus, are explored. Examination and review of the clinical and research findings in the literature relating to perio-endo lesions are made to demonstrate that a negative influence may exist between GTR outcomes and the status of the pulp.