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PubMed2006

Lung disease 35 years after aspiration of activated charcoal in combination with pulmonary lymphangioleiomyomatosis. A histological and clinicopathological study with scanning electron microscopic evaluation and element analysis.

Activated charcoal provides effective treatment for most toxic ingestions. Accidental aspiration of activated charcoal is rare. Previously, there have been a few single cases reported on charcoal-related pulmonary complications. We describe an unusual case of pulmonary lesions 35 years after accidental aspiration of activated charcoal. The 38-year-old female patient presented with recurrent pneumothorax. A routinely performed chest roentgenogram revealed pulmonary lesions, highly suggestive to lymphangioleiomyomatosis (LAM). Histopathological investigation of the lung tissue demonstrated some features of LAM but showed prominent pneumoconiotic lesions with cystic tissue destruction. The pneumoconiotic reaction was characterized by prominent black deposits accompanied by foreign-body granuloma formation and minimal fibrosis. Scanning electron microscopic investigation of these deposits showed particles measuring up to 300 microm in greatest diameter. Energy-dispersive X-ray spectra of these particles revealed carbon-rich material, presumably charcoal. The aspiration event was confirmed by the clinical history. To our knowledge, this is the first report not only on a long-term follow-up after aspiration of activated charcoal but also on charcoal-related pulmonary lesions in combination with LAM.

Adult↗

PubMed2006

[Scanning electron microscopic study on the use of traditional Chinese medical irrigant in ultrasonic root canal instrumentation].

PURPOSE: To evaluate the cleaning ability of traditional Chinese medicine Jieeryin used as ultrasonic root canal irrigant. METHODS: A total of 20 extracted human single-rooted teeth were divided into 4 groups: normal saline, 3.33% Jieeryin, 30% Jieeryin and 2.5% sodium hypochlorite. After ultrasonic root canal preparation a 15#-K type ultrasonic file was inserted into the root canal without contacting the root canal wall and the ultrasonic irrigation was kept for 10 seconds. The cleaning of the cervical, middle and apical thirds of the root canal walls was evaluated by scanning electron microscope. The data were analyzed statistically by ANOVA and Bonferroni test. RESULTS: The cleaning ability of 30% Jieeryin was similar to that of 2.5% NaClO (P>0.05) in the cervical third, and it was significantly better than 3.33% Jieeryin (P<0.01) and normal saline (P<0.05). There was significant difference between the cervical third and the middle or apical thirds (P<0.01) of 30% Jieeryin. There was no significant difference between the four groups in the middle third (P>0.05). In the apical third, 2.5% NaClO was significantly better than normal saline (P>0.05). No significant difference was found between 3.33% Jieeryin and saline in all thirds. CONCLUSION: Cleaning by 30% Jieeryin or 2.5% NaClO with ultrasonic technique was superior compared to the cleaning by 3.33% Jieeryin or normal saline in the cervical third.

Dental Pulp Cavity↗

PubMed1990

A scanning electron microscopic investigation of bonding of methacryloyloxyalkyl hydrogen maleate to etched dentin.

Three types of methacryloyloxyalkyl hydrogen maleates--2-(methacryloyloxy)ethyl hydrogen maleate (2MEM), 1-(methacryloyloxy-methyl)ethyl hydrogen maleate (MMEM), and 1-(methacryloyloxymethyl)propyl hydrogen maleate (MMPM)--were prepared for use as bonding agents. The relationships between the thickness of an acid-proof dentin layer and the bond strength and chemical structure of the synthesized monomers were investigated. The bond strengths of 2MEM/composite system to dentin treated with either 37% phosphoric acid solution or 10% citric acid-3% ferric chloride solution (10-3 solution) were superior to those of the others. The acid-proof dentin layer for all bonding agents containing the synthesized monomers at the resin-dentin interface was clearly visible in a scanning electron microscope, regardless of the types of dentin etching agents used. After treatment of the dentin with the phosphoric acid solution, the layers of 2MEM, MMEM, and MMPM were 5-6 micron, 3-4 micron, and 2-3 micron thick, respectively. When the dentin was treated with the 10-3 solution, the layer for each bonding agent was approximately 1 micron thick.

Acid Etching, Dental↗

PubMed2005

Effectiveness in cleaning oval-shaped root canals using Anatomic Endodontic Technology, ProFile and manual instrumentation: a scanning electron microscopic study.

AIM: To compare in vitro the cleanliness of root canal walls in oval-shaped root canals following automated or manual instrumentation. METHODOLOGY: Forty-five oval-shaped single-rooted maxillary and mandibular premolars with straight canals were divided into three groups of 15. Automated canal preparation was performed using Anatomic Endodontic Technology (AET, group 1) and the ProFile system (group 2). Manual instrumentation (group 3) was performed with K-Flexofiles. Irrigation was performed using alternately 5.25% NaOCl and 17% EDTA, followed by rinsing with saline. The roots were split longitudinally into halves and the canals examined at x200 and x400 in a scanning electron microscope. The presence of debris and smear layer was recorded at distances of 1, 5 and 10 mm from the working length using a three-step scoring scale and a 300 mum square grid. Mean scores for debris and smear layer were calculated and statistically analysed for significance (P < 0.05) between and within groups, using the Kruskal-Wallis nonparametric anova and Dunn's tests. RESULTS: At 1, 5 and 10-mm levels the root canals prepared with AET had significantly less surface debris and smear layer on the canal walls compared with canals prepared with ProFile or manual instrumentation. For all three groups significantly lower mean smear layer scores (P < 0.05) were recorded at 5 and 10-mm levels compared with the 1 mm level. Significantly lower mean debris scores (P < 0.05) were also recorded at 5 and 10-mm levels for the AET group whereas no significant differences were found between the three levels for the ProFile and manual instrumentation groups. CONCLUSIONS: Although better instrumentation scores were obtained in canals prepared with AET, complete cleanliness was not achieved by any of the techniques and instruments investigated.

Analysis of Variance↗

PubMed1995

The choice of irrigant during hand instrumentation and ultrasonic irrigation of the root canal: a scanning electron microscope study.

The purpose of this study was to investigate the use of 4 per cent sodium hypochlorite and 15 per cent EDTAC, either alone or in conjunction, as irrigants during hand instrumentation and ultrasonic irrigation of the root canal. Thirty-six extracted human teeth, each with a single, straight root 21-25 mm long were hand-instrumented through a clinical access cavity to file size 40. One millilitre of the test irrigant was used after each instrument size. Canal debridement was completed with an intermittent flush irrigation technique with one or both of the test irrigants activated by ultrasound at a medium effective power output. The specimens were sectioned longitudinally, viewed in a scanning electron microscope and scored for the presence or absence of debris and smear layer at levels less than 1 mm, 5 mm, and 10 mm from the apical seat. Under the conditions of this experiment the most effective regime was irrigation with 1 mL EDTAC after each instrument size, followed by two 30 second exposures to ultrasound+EDTAC then four 30 second exposures to ultrasound + 4 per cent sodium hypochlorite. The specimens in this group were free from retained pulp tissue and superficial smear layer, had the lowest debris scores at the < 1 mm and 5 mm levels, and the lowest total debris score. All of the techniques tested produced smear-free canals at the 10 mm level.

Dental Pulp↗

PubMed1998

A scanning electron microscopic study of tooth surface changes induced by tannic acid.

STATEMENT OF PROBLEM: Exposing the tooth structure to chemicals used in displacing the gingival tissue is inevitable. PURPOSE: This study was undertaken to microscopically examine the effect of tannic acid on the prepared dentin surface. MATERIAL AND METHODS: Forty recently extracted intact human teeth were mounted for buccal surface preparation. Teeth were equally divided into 10 groups. One group was kept as a control and the other teeth received a topical application of 15%, 20%, and 25% aqueous tannic acid solutions each for 5, 10, and 15 minutes at room temperature. All samples were washed, air-dried, then prepared for scanning electron microscopic examination. Two different areas in the cervical region were randomly selected and examined under magnifications of x1000 and x2000, then photographed. The assessment of the changes was performed qualitatively. RESULTS: The results showed an incomplete removal of the smear layer in all experimental samples. The astringent action of the tannic acid solution on both the smear layer and the surface peritubular dentin around the orifices of dentinal tubules had contributed to their constriction. The degree of constriction of the orifices of dentinal tubules increased as higher concentrations of tannic acid solutions were used and as the application time was further increased at each concentration. CONCLUSION: The tannic acid had an incomplete action on the removal of the smear layer. It also seemed to have an astringent action on both the smear layer and the peritubular dentin.

Astringents↗

PubMed2006

Efficacy of a new brush-covered irrigation needle in removing root canal debris: a scanning electron microscopic study.

The usefulness of NaviTip FX, a brush-covered irrigation needle, in endodontic therapy has never been reported. Therefore, the purpose of this investigation was to evaluate the cleaning efficacy of this new brush-covered irrigation needle, the NaviTip FX. Thirty single-rooted teeth were randomly divided into two equal groups and instrumented using the crown-down technique with 0.04 taper ProFile. Following each file use, the canals were irrigated with 1 ml of 5.25% NaOCl using the NaviTip FX needle for group 1 or using the same needle without the brush for group 2. At the end of instrumentation, the roots were cut longitudinally and each half was divided into three equal parts. The specimens were then routinely prepared for scanning electron microscopic evaluation. The results showed that using the NaviTip FX produced cleaner coronal thirds of instrumented root canals compared to the control group. On the other hand, the middle and apical thirds were not statistically significantly different between the two groups. Further development of this irrigation technique to improve cleanliness of the apical and middle thirds is required before the NaviTip FX can be recommended for routine use during root canal therapy.

Dental Equipment↗

PubMed2002

Scanning electron microscopic investigation of the surface of fiber posts after cutting.

This study evaluated the surface of different types of fiber posts after cutting and investigated whether different cutting procedures can affect the integrity of the posts. Six types of fiber posts were selected for this study (Carbon Fiber Posts, Quartz Fiber Posts, Aesthetic Posts, Aesthetic Plus Posts, Translucent Posts, Dentatus, FRC Postec Posts). Fifteen posts of each type were studied. All posts had a diameter of 1.2 to 1.4 mm and were between 14 and 16 mm long. Each group was divided into three subgroups (n = 5) according to cutting method: diamond bur, carborundum disk, or scissors. The samples were then processed for scanning electron microscopic investigation. At low magnifications, no microscopic differences were found among the samples of groups 1-4 and 6. Surfaces from group 5 were more irregular, but only when cut using rotating instruments. All groups showed differences between surfaces cut with scissors and those cut with either diamond bur or carborundum disk. Posts displayed regular surfaces after cutting with a diamond bur. Cutting with a carborundum disk produced a mostly regular surface but sometimes produced irregularities close to the surface borders. The surfaces cut with scissors showed two plane and convergent flanges, and because of the formation of fracture lines these posts lost their integrity not only at the cutting surface but also along their length. The results of this study indicated that fiber posts can be cut using a diamond bur mounted in a handpiece under copious water coolant. Although the carborundum disk cutting procedure showed a less regular post surface, it can be speculated that it might be clinically acceptable. The cutting procedure using scissors should be avoided.

Alloys↗

PubMed2004

Microbiological study and scanning electron microscopic analysis of root canal wall dentin following pumped Diodium Nd:YAG laser irradiation.

The capability of Nd:YAG laser in sterilizing root canals and the alterations of dentinal walls induced by laser treatment were investigated. Thirty root canals were infected by P. aeruginosa ATCC 27853 and thirty canals by A. naeslundii CH-12. Within each infection, 4 groups were selected on the basis of the treatment. Among them, 2 test groups (TGs) were treated by Nd:YAG laser at 15 Hz for 15 s, using 2 different settings: 1 Watt/70 Joule and 1.5 Watt/100 Joule, respectively (n = 10 each). The other 2 groups, used as controls (CGs), were: untreated (positive control, n = 5) and sterilized by 5.25% NaClO group (negative control, n = 5). Observations under scanning electron microscope (SEM) and quantitative bacterial counts were performed. These analyses were performed once per group after infections and treatments. Laser treatments significantly reduced the number of both bacteria. SEM investigation showed melting and crystallization of canal dentin over 1.5 W/100 J. Laser irradiation has a bactericidal effect but it does not completely sterilize the root canal as NaClO 5.25% solution does if the goal of treatment is also to avoid alterations of dentinal walls.

Actinomyces↗

PubMed2004

Partial ceramic crowns. Influence of preparation design and luting material on margin integrity--a scanning electron microscopic study.

This in vitro study examines the effects of three preparation designs and different luting agents on the marginal integrity of partial ceramic crowns. One hundred forty-four extracted human molars were prepared according to the following preparation designs: A. Coverage of functional cusps, B. Horizontal reduction of functional cusps and C. Complete reduction of functional cusps. Partial ceramic crowns (Vita Mark II, Cerec 3 System) were bonded to the cavities with: Variolink II/Excite (Vivadent), Panavia F/ED primer (Kuraray), Dyract/Prime and Bond NT (Detrey/Dentsply), and Fuji Plus/GC cavity conditioner (GC). The specimens were exposed to thermocycling and mechanical loading. Marginal adaptation was assessed on replicas using quantitative margin analysis in the scanning electron microscope (SEM). Significant differences were observed between the preparation designs in general. Coverage of functional cusps with preparation of butt joints and use of Variolink as luting material showed a tendency toward the lowest values for compromised adhesion, especially within the dentin. Significant differences could be determined between luting systems: resin-modified glass ionomer cement (RMGIC) caused fracture of the restorations and revealed higher values than all other luting materials for compromised adhesion at ceramic-luting agent and tooth-luting agent interfaces. The dentin-luting material interface, in general, showed higher percentages of compromised adhesion (38-100%) than enamel- and ceramic-luting material interfaces (0-30%). In conclusion, the SEM data indicate that, with adhesively bonded partial ceramic crowns, retentive preparation is not contraindicated and the choice of luting material is more relevant than the preparation design. Margins below the cemento-enamel junction reveal significant loss of adhesion in spite of adhesive luting techniques. The RMGIC cannot be recommended as a luting material for feldspathic partial ceramic crowns.

Ceramics↗

PubMed1983

A scanning electron microscopic study of the odontoblast process in human coronal dentine.

It is generally accepted that the odontoblast process occupies the dentinal tubules only in the inner part of the dentine, extending approx 0.7 mm from the pulp in both animals and man. Twenty-three premolars, molars and third molars from subjects aged 11-24 yr, all caries-free or only slightly decayed, were processed immediately after extraction by one of four methods. (I) Teeth were split in liquid nitrogen and then fixed, dehydrated in ascending ethanol, and dried by critical point drying (CPD). (II) Teeth were fractured by use of a mallet and a chisel and then prepared as in Method I. (III) The root was cut off using a diamond disk or a mallet and a chisel and the crown was then fixed, fractured in liquid nitrogen, dehydrated and CPD. (IV) As Method III but following fixation the teeth were freeze-dried. All specimens were examined in the scanning electron microscope (SEM). In specimens prepared by Methods II, III or IV the odontoblast process was limited to the inner third of crown dentine. However in all the specimens prepared by Method I the odontoblast process extended to the dentine-enamel junction.

Adolescent↗

PubMed2006

Quantitative detection of individual cleaved DNA molecules on surfaces using gold nanoparticles and scanning electron microscope imaging.

Single-nucleotide polymorphisms (SNPs) are the most frequent type of human genetic variation. Recent work has shown that it is possible to directly analyze SNPs in unamplified human genomic DNA samples using the surface-invasive cleavage reaction followed by rolling circle amplification (RCA) labeling of the cleavage products. The individual RCA amplicon molecules were counted on the surface using fluorescence microscopy. Two principal limitations of such single-molecule counting are the variability in the amplicon size, which results in a large variation in fluorescence signal intensity from the dye-labeled DNA molecules, and a high level of background fluorescence. It is shown here that an excellent alternative to RCA labeling is tagging with gold nanoparticles followed by imaging with a scanning electron microscope. Gold nanoparticles have a uniform diameter (15 +/- 0.5 nm) and provide excellent contrast against the background of the silicon substrate employed. Individual gold nanoparticles are readily counted using publicly available software. The results demonstrate that the labeling efficiency is improved by as much as approximately 15-fold, and the signal-to-noise ratio is improved by approximately 4-fold. Detection of individual cleaved DNA molecules following surface-invasive cleavage was linear and quantitative over 3 orders of magnitude in amount of target DNA (10(-18)-10(-15) mol).

DNA↗

PubMed1988

[Scanning electron microscope study of early bacterial penetration of human enamel in initial caries].

Bacterial penetration of enamel during initial manifestations of the carious process was studied in intact buccal enamel of 8 impacted third permanent molars. After cleaning them from organic plaque, each buccal plane was cut into five segments, one of them serving as a control specimen and the other four being fixed into slots on partial prostheses of our volunteers. The specimens were left in oral cavity for 7, 14, 21 and 28 days, where they were exposed to the action of cariogenic factors. After removal of the organic plaque, the specimens were broken in two and the bacterial penetration into enamel was observed on the fractured cross-section using scanning electron microscope. In 4 specimens from the group orally exposed during a 7-day period, individual coccoid or bacilliform bacteria were found to have penetrated 5-10 microns deep. The number of bacteria and the depth of their penetration into enamel increased with the duration of oral exposition. Among the specimens orally exposed during 28 days, bacteria were observed to be present both individually and in colonies, penetrating to the depth of 60-90 microns. These bacteria could quite easily communicate with saliva and plaque via the pore system, which allowed them to produce metabolites, including lactic acids. This, in turn, allowed them to penetrate through the enamel, thus altering both the course and rate of the carious process progression.

Bacteria↗

PubMed1992

Expression of B and H antigens on red cells from a group B(weak) individual studied by serologic and scanning electron microscopic techniques.

The proposita was classified as B(el), B(y), or B(m), Le(b+) by routine blood grouping and by adsorption/elution studies using anti-A and -B hyperimmune pregnancy sera. Red cells from the proposita adsorbed as much anti-B from the hyperimmune sera as did red cells from normal B individuals, but adsorbed less anti-A,B (group O serum). Saliva contained H, but not B, soluble substance. Red cells from the proposita and a normal B donor were sensitized with monoclonal A and B blood group antibodies immunolabeled with colloidal gold particles, and examined in a scanning electron microscope. B antigens were found on more than 95 percent of normal B cells, but on only 2-3 percent of red cells from the proposita. However, when the same cells were sensitized with anti-A,B that reacted strongly with B oligosaccharides other than type 2 chains, half of the labeled red cells from the proposita were labeled more strongly than any normal B cells. Our results explain why red cells from the proposita adsorb significant amounts of anti-B and anti-A,B without being agglutinated by these antibodies. The results of both adsorption/elution and immunolabeling suggest that the B antigen on her cells differs biochemically from that on normal B cells.

Journal Article↗

PubMed2006

A scanning electron microscopic study of debris and smear layer remaining following use of AET instruments and K-flexofiles.

AIM: To compare in vitro the cleanliness of root canal walls following automated or manual instrumentation. METHODOLOGY: Thirty extracted human maxillary central incisors, maxillary and mandibular canines and premolars with single root canals were used in this study. The teeth were divided into two groups. In group 1 (20 teeth) automated canal preparation was performed using Anatomic Endodontic Technology (AET). In group 2 (10 teeth) manual instrumentation was performed with K-Flexofiles. Irrigation was performed using alternately 3.00% NaOCl and 18% EDTA, followed by rinsing with saline. The roots were split longitudinally into halves and the canals examined using a scanning electron microscope. The presence of debris and smear layer was recorded at coronal, middle and apical thirds of root canals using a four-step scoring scale. Mean scores for debris and smear layer were calculated and statistically analysed for significance (P<0.05) between and within groups, using the Mann-Whitney-Wilcoxon and Friedman nonparametric tests. RESULTS: At coronal and middle thirds the root canals prepared with manual instrumentation had significantly less surface debris on the canal walls compared with canals prepared with AET (p<0.05). At apical third root canals prepared with manual instrumentation had significantly more debris compared with AET group. The amount of smear layer was greater in the apical than in the coronal and middle thirds of the root and significantly less amount was in the AET group (P<0.05). CONCLUSIONS: Complete cleanliness was not achieved by any of the techniques and instruments investigated. It may be inferred that the choice between AET and hand instrumentation should be based on factors other than the amount of root canal debridement, which does not vary high significantly according to the instruments used.

Chelating Agents↗

PubMed1981

A study of mitosis, meiosis, histology, and scanning electron microscopic details of spermatogenesis in an infertile male with probable 46,XY/47,XXY germinal mosaicism.

A 29-year-old infertile man with mild eunuchoid body proportions and unilateral gynecomastia with a low sperm count had normal chromosomes in lymphocytes and skin fibroblasts. Serum testosterone, urinary ketosteroid, and follicle-stimulating hormone levels were normal, but serum prolactin, luteinizing hormone, and estrogen levels were above normal. Testicular biopsy showed hypocellularity, a pacuity of maturing sperm, and increased lipid content in early spermatogonia. Cytogenetic analysis of the testicular material showed probable 46,XY/47,XXY mosaicism in spermatogonial cells. None of the cells in diakinesis and metaphase I showed the extra-X as a univalent, and 50% of the cells in diakinesis were hypodiploid with intact XY bivalents. Further analysis of spermatogenesis revealed polymorphic dyads, triads, tetrads, and uncleaved meiotic products of first and second meiosis. Sex chromatin studies of testicular cells showed that 20% of the cells were X-chromatin positive. Scanning electron microscopic study of sperm revealed a wide range of polymorphisms, with some uncleaved meiotic products maturing into double-headed and double-tailed sperm or sperm with bulbous middle pieces or protrusions. A cytogenetic basis for the origin of these abnormalities is presented.

Adult↗

PubMed1987

Effect of gossypol acetic acid on the epididymis: histochemical and scanning electron microscope studies.

Rats were treated orally with gossypol acetic acid at 30 or 10 mg/kg daily, 6 days a week, for 8, 12, 14 or 16 weeks. At the end of each treatment regimen, treated rats and an equal number of control rats were killed for histological and histochemical studies. From 8 weeks onward, as a result of the treatment, the tubular lumen of the corpus epididymides became narrowed with thickened pseudostratified epithelium and there was a reduction in the amount of spermatozoa. There was an increase in esterase, alkaline phosphatase, acid phosphatase and ATPase activity. These changes increased in intensity with the duration of treatment. Scanning electron microscopic examinations of the corpus epididymides of rats treated for 16 weeks, compared with those of controls, revealed similar changes, namely, narrowing of the tubular lumen, thickening of the pseudostratified epithelium and reduction in the number of spermatozoa.

Animals↗

PubMed1995

Scanning electron microscopic observation of dark cells after streptomycin perfusion of the vestibule in guinea pigs.

Hearing has been stabilized in the majority of patients studied in the treatment of Meniére's disease with streptomycin. This observation suggests that effects of streptomycin may ameliorate endolymphatic hydrops, possibly by attenuating the activity of secretory tissue. The purpose of this study is to observe the dark cells of the utricle in guinea pigs after streptomycin perfusion of the vestibule. Twelve pigmented guinea pigs weighing 250-350 grams were used in this study. The vestibules in five guinea pigs were perfused monolaterally with 150 micrograms of streptomycin in artificial perilymph and, in seven, the vestibules were perfused only with artificial perilymph as a control group. Specimens were processed for observation with a scanning electron microscope. After streptomycin perfusion, the margin of the dark cells became indistinct. The luminal surface of the cells bulged out like a dome. The microvilli decreased or were absent, and some debris was deposited on the surface. In four of the five animals, the luminal membrane of the dark cell ruptured. The cytoplasm and organelle extruded into the endolymphatic space. After the cellular debris moved out into the endolymph, either a vanished cell or a nucleus in an empty nest was observed. These cells appeared damaged and destroyed. The results indicate that the dark cells in the membranous wall of the utricle were affected by streptomycin. The results lead to the assumption that streptomycin may reduce the volume of endolymph by damaging the dark cells of the utricle.

Animals↗