PURPOSE: The aim of this study was to evaluate the effect of Er:YAG laser on microstructure and roughness of TiO2 blasting implant surface. MATERIALS AND METHODS: Ten TiO2 blasting implant were used in this experiment. One implant was control group, and nine TiO2 blasting implant surfaces were irradiated with Er:YAG laser under 100 mJ/pulse, 140 mJ/pulse, and 180 mJ/pulse condition for 1 min, 1.5 min, and 2 min respectively. Optical interferometer and scanning electron microscopy was utilized to measure roughness and microstructure of specimens. RESULTS: The surface roughness was decreased after Er:YAG laser irradiation in all groups, but there was no significant difference. 100 mJ/pulse and 140 mJ/pulse group did not alter the TiO2 blasting implant surface in SEM study while 180 mJ/pulse group altered the TiO2 blasting implant surface. Implant surfaces showed melting, microfracture and smooth surface in 180 mJ/pulse group. CONCLUSION: Detoxification of implant surface using Er:YAG laser must be irradiated with proper energy output and irradiation time to prevent implant surface alteration.
Freezing ; Microscopy, Electron, Scanning

Megaselia scalaris (Loew) (Diptera: Phoridae) is a cosmopolitan scuttle fly of medical and forensic importance. This species is generally small, humpbacked and is a prominent decomposer of corpses indoors. Taxonomically, adult sexes can be distinguished based on the characteristics of the terminal segments of the abdomen. In this report, the terminalia of adult male and female M. scalaris were examined using scanning electron microscope (SEM). The terminal segment of an adult female is less complex compared to male, consisting of an ovipositor and cerci. In male, the hypopygium consists of epandrium, hypandrium, anal tube and penis complex. A pair of long and feathered setae was attached to the tip of the anal tube and tapered. The application of SEM to identify this species isuseful and can be expanded to other species in this fly group.
Microscopy, Electron, Scanning

OBJECTIVES: The aim of this study was to evaluate the mechanical and physical properties of a newly developed fiber reinforced dental composite. MATERIALS AND METHODS: Fiber reinforced composite EverX Posterior (EXP, GC EUROPE), and other commercially available bulk fill composites, including Filtek Bulk Fill (FB, 3M ESPE), SonicFill (SF, Kerr Corp.), SureFil (SDR, Dentsply), Venus Bulk Fill (VB, HerausKultzer), Tetric evoceram bulk fill (TECB, Ivoclar Vivadent), and Xtra Base (XB, Voco) were characterized. Composite samples light-cured with a LED device were evaluated in terms of flexural strength, flexural modulus (ISO 4049, n = 6), fracture toughness (n = 6), and Vickers hardness (0, 2, and 4 mm in depth at 24 hr, n = 5). The EXP samples and the fracture surface were observed under a scanning electron microscopy. Data were statistically analyzed using one-way ANOVA and unpaired t-test. RESULTS: EXP, FB, and VB had significantly higher fracture toughness value compared to all the other bulk composite types. SF, EXP, and XB were not statistically different, and had significantly higher flexural strength values compared to other tested composite materials. EXP had the highest flexural modulus, VB had the lowest values. Vickers hardness values revealed SF, EXP, TECB, and XB were not statistically different, and had significantly higher values compared to other tested composite materials. SEM observations show well dispersed fibers working as a reinforcing phase. CONCLUSIONS: The addition of fibers to methacrylate-based matrix results in composites with either comparable or superior mechanical properties compared to the other bulk fill materials tested.
Hardness ; Microscopy, Electron, Scanning ; Venus

The purpose of this study was to compare the changes of retentive force in different stud attachment systems for implant retained overdenture. Two commercially available attachments with different retentive forces were investigated: Kerator (pink, blue, red) and O-ring (orange, red). Two implant fixtures were vertically embedded in base mountings. Five pairs of each attachment were evaluated. A universal testing machine was used to evaluate the retentive force of two attachments during wear simulation. Surface characteristics of each attachment system were evaluated with scanning electron microscopy. Five pairs of each attachment were evaluated. Kerator pink showed the highest initial retention. After 2,500 cycles of wear-simulation, Kerator pink noted the largest decrease in retention. According to results of surface analysis, Worn surfaces were obtained in matrices and patrices. Heavy wears were observed in matrices. After 2 year-wear simulation, most attachments exhibited retention loss. Attachments using different kind of material exhibited dissimilar surface alterations.
Denture, Overlay* ; Microscopy, Electron, Scanning

BACKGROUND AND OBJECTIVES: Colonization of microorganisms on pollutants is the first indication of the potential ability of microbes to utilize plastic pollutants as a carbon source by sequential biodegradation into usable form for sustenance. The Philippines is considered the third highest country contributing to global mismanaged plastic waste. To locally manage and find a natural and innovative solution to this worldwide concern, this study aimed to evaluate the capacity of Xylaria sp. SDM (sterile dark mycelia) wild type, which was previously reported to colonize polyethylene plastic and mutant strains to colonize polystyrene, a plastic pollutant widely produced in the world. Assessment of the ability of local Xylaria sp. strains to grow, penetrate, and damage the surface and inner structures of polystyrene was investigated using scanning electron microscopy (SEM).

METHODOLOGY: Xylaria sp. strains were cultured in a pH 5.0 mineral medium with 0.5% glucose as carbon source and polystyrene as a co-carbon source, and stored at 25?C for 50 days. At the end of the incubation period, due to irremovable fungal strains on the surface of the polystyrene strips, samples of polystyrene from each strain were subjected to SEM.

RESULTS: On the 20th day of incubation, the presence of mucilaginous sheaths and fungal growth was observed on the surface of treated polystyrene strips. At the end of the 50-day incubation period, scanning electron microscopy (SEM) confirmed fungal growth and colonization, through the presence of mycelial mats and hyphae, of the wild type and mutant strains on the surface and inner structures of polystyrene except the control. Moreover, physical surface damage in the form of holes, cracks, and crevices on polystyrene demonstrated the active burrowing action of Xylaria sp. strains further supporting the potential of this fungus to damage polystyrene plastic.

CONCLUSION: Whereas fungal growth on a polymer surface is necessary but not sufficient to conclude the process of carbon assimilation as the final biodegradation step, the initial colonization of Xylaria sp. strains on polystyrene supports its ability to establish itself and physically damage the pollutant. Hence, this study extended the existing knowledge on the colonizing ability of Xylaria sp. on plastic making it a potential candidate organism to biodegrade plastic waste, which is one of the topmost environmental waste hazards in the world today.

The section of Annulata under genus Hypoxylon is a member of the Xylariaceae which has ascomata with ostioles papillate ill a flattened disc. The isolates of Hypoxylon collected from the Tropic to the Temperate are compared with similar taxa and described. These isolations under Annulata section are illustrated with a light microscopy and a scanning electron microscopy. Hypoxylon archeri is newly recorded from Korea. A key to the species is also included.
Fungi* ; Korea ; Microscopy ; Microscopy, Electron, Scanning ; Wood*

The aim of this study was to evaluate the effect of two polishing methods and chemical conditioning on the surface of hybrid composites. Ninety cylindrical specimens (diameter: 8 mm, depth: 2 mm) were made with three hybrid composites - Filtek Z250, Tetric Ceram, DenFil. Specimens for each composite were randomly divided into three treatment subgroups - Mylar strip (no treatment), Sof-Lex XT system, PoGo system. Average surface roughness(Ra) was taken using a surface profilometer at the time of setting and after immersion into 0.02N lactic acid for 1 week and 1 month. Representative specimens were examined by scanning electron microscopy. The data were analyzed using ANOVA and Scheffe's tests at 0.05% significance level. The results were as follows: 1. Mylar strip resulted in smoother surface than PoGo and Sof-Lex system(p<0.001). Sof-Lex system gave the worst results. 2. Tetric Ceram was smoother than DenFil and Z250 when cured under only mylar strip. However, it was significantly rougher than other materials when polished with PoGo system. 3. All materials showed rough surface after storage in 0.02N lactic acid, except groups polished with a PoGo system. The PoGo system gave a superior polish than Sof-Lex system for the three composites. However, the correlation to clinical practice may be limited, since there are several processes, such as abrasive, fatigue, and corrosive mechanisms. Thus, further studies are needed for polishing technique under in vivo conditions.
Fatigue ; Immersion ; Lactic Acid ; Microscopy, Electron, Scanning

OBJECTIVETo investigate morphological change of osteoblasts cultured on titanium plates with different microarchitecture structure when exposured to fluid shear stress.

METHODS14 dynes x cm(-2) fluid shear stress was applied on osteoblasts cultured on 3 different commercially pure titanium plates: Polished treatment (PT), sandblast (SB), sandblasting and acid-base (SB-AB) surfaces. Scanning electron microscope (SEM) was adopted to observe the morphological changes after 0.5, 4, 7.5 h time point respectively.

RESULTSMorphologically, no significant changes were observed after 0.5 h and few osteoblasts were seen after 7.5 h on all 3 type of different surfaces, and significant changes could only be observed after 4 h. Osteoblasts were elongated and rearranged along the flow way on different levels on PT surface. Shape of cells was altered, from long fusiform suspending over depressed areas into polygon stretching out many synapsises tightly attached to pits on SB-AB surface. Osteoblasts on SB surface displayed similar change as SB-AB surface, besides, some cells were elongated along the way of flow, stretching out threadlike synapsises attached to edges of pits.

CONCLUSIONMorphological change of osteoblast responding to fluid shear stress in physiological range depends on substrate microarchitecture and varies with the time of fluid shear stress application.

A knife-edge method is used here to measure the beam width of the highly repetitive high-power thin disk Yb:KYW femtosecond laser (MABEL-Mannheim Biomedical Engineering Lab, University of Heidelberg, Germany). Presented in this paper is the detailed measuring process together with the results verified by theoretical calculating and scanning electron microscope measurements respectively. Therefore, it is concluded that the knife-dege method is an effective beam width measurement tool of high-power femtosecond lasers.
Bioengineering ; instrumentation ; Lasers ; Microscopy, Electron, Scanning ; instrumentation

OBJECTIVE: The aim of this study was to compare recycled and unused orthodontic miniscrews to determine the feasibility of reuse. The comparisons included both miniscrews with machined surfaces (MS), and those with etched surfaces (ES). METHODS: Retrieved MS and ES were further divided into three subgroups according to the assigned recycling procedure: group A, air-water spray; group B, mechanical cleaning; and group C, mechanical and chemical cleaning. Unused screws were used as controls. Scanning electron microscopy, energy-dispersive X-ray spectrometry, insertion time and maximum insertion torque measurements in artificial bone, and biological responses in the form of periotest values (PTV), bone–implant contact ratio (BIC), and bone volume ratio (BV) were assessed. RESULTS: Morphological changes after recycling mainly occurred at the screw tip, and the cortical bone penetration success rate of recycled screws was lower than that of unused screws. Retrieved ES needed more thorough cleaning than retrieved MS to produce a surface composition similar to that of unused screws. There were no significant differences in PTV or BIC between recycled and unused screws, while the BV of the former was significantly lower than that of the latter (p < 0.05). CONCLUSIONS: These results indicate that reuse of recycled orthodontic miniscrews may not be feasible from the biomechanical aspect.
Microscopy, Electron, Scanning ; Recycling* ; Spectrum Analysis ; Torque