Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Erbium”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 127 records · Page 7Linked to original sources

[Analysis of photo-ablation products of excimer and erbium:YAG laser treated human corneas. Combined gas chromatography/mass spectroscopy].

The photoablation products from human cadaver corneas treated with an excimer laser (192 nm) or an erbium: YAG laser (2.94 microns) were qualitatively analyzed using a combined gas chromatography mass spectrometry (GC/MS) system. GC/MS is the most sensitive analyzing system in use today for molecules with a relative molecular mass of 40 to 400. More than 20 different types of molecules were detected; most of them were identified as alkanes. Comparison of the two types of laser showed larger fragments and fewer different types of molecules after excimer laser treatment than after erbium: YAG photoablation. We postulate that the smaller molecules after erbium: YAG treatment indicate a greater heat during photoablation than with excimer laser treatment.

Alkanes↗

A new and improved vitreoretinal erbium:YAG laser scalpel: long-term morphologic characteristics of retinal-choroidal injury.

BACKGROUND AND OBJECTIVE: To report a modified erbium:YAG laser scalpel designed to incise tissue more efficiently and safely than other systems reported to date. MATERIALS AND METHODS: An erbium:YAG laser delivery system was built to deliver laser energy in bursts of micropulses with a repetition rate of 1,000 Hz. The laser was coupled to handpieces with tip designs equipped with shields, backstops, and beveled, straight, and flexible fibers. In vivo studies in the rabbit eye were performed to determine damage threshold, optimal pulse energy, and burst frequency required to make incisions in the retina and choroid. The safety profile and directional control provided by the handpieces were tested for consistency. Partial- and full-thickness retinal-choroidal incisions were examined clinically and histologically at various time intervals. RESULTS: The best incisions were obtained at a fluence of 3.5 J/cm2 or greater, a burst repetition rate of 10 to 40 Hz, and 6 micropulses per burst. Retinal damage occurred when incising laser energy was used 500 microm or closer to the retinal surface. Depth of penetration of laser energy did not depend on burst repetition rate. The use of laser endoprobes equipped with shields and backstops provides absolute protection from stray laser energy in aqueous media. The use of flexible beveled fiber tips provides reliable, accurate directional control. Retinal-choroidal incisions and damage resulted in local retinal-choroidal degeneration and adhesion formation. CONCLUSION: The modifications to the erbium:YAG laser scalpel provide a more efficient, versatile, and safe application to vitreoretinal surgery than any system reported to date.

Animals↗

Comparison of erbium:YAG and carbon dioxide lasers in resurfacing of facial rhytides.

OBJECTIVE: To compare the efficacy, adverse effects, and histological findings of erbium:YAG (Er:YAG) and carbon dioxide (CO2) laser treatment in removing facial rhytides. DESIGN: An intervention study of 21 subjects with facial rhytides. All participants were followed up for 6 months. The end points of the study were wrinkle improvement and duration of adverse effects. SETTING: Academic referral center. SUBJECTS: Nineteen female and 2 male volunteers with skin type I to III and wrinkle class I to III participated in the study. INTERVENTION: In all subjects, 1 side of the face was treated with a CO2 laser and other side with an Er:YAG laser. Skin biopsies were performed in 6 subjects before treatment and immediately, 1 day, 2 days, and 6 months after treatment. Observations were recorded by subjects, investigators, and a blinded panel of experts. MAIN OUTCOME MEASURES: Improvement in wrinkles and severity and duration of adverse effects. RESULTS: The CO2 laser-treated side had relatively better wrinkle improvement when evaluating all subjects (P<.03). However, in subjects receiving more than 5 passes of Er:YAG laser, improvement scores were not significantly different from those for 2 to 3 passes of CO2 laser treatment. Posttreatment erythema was noted at 2 weeks in 14 subjects (67%) on the Er:YAG laser-treated side and 20 subjects (95%) on the CO2 laser-treated side. The frequency of erythema was significantly less after Er:YAG laser treatment at 2 (P=.001) and 8 (P=.03) weeks. Hypopigmentation was seen in 1 Er:YAG-treated (5%) and 9 CO2-treated (43%) sides (chi2, P<.05). Histological evaluation showed residual thermal damage of up to 50 microm on the Er:YAG-treated side and up to 200 microm on the CO2-treated side. CONCLUSIONS: Erbium:YAG laser is safe and effective in removing facial rhytides. Subjects treated with Er:YAG laser recover more quickly from the procedure than those receiving CO2 laser treatment.

Adolescent↗

Xanthelasma palpebrarum: treatment with the erbium:YAG laser.

BACKGROUND AND OBJECTIVE: Xanthelasma palpebrarum presents a therapeutic and aesthetic challenge because of its high visibility and frequent rate of recurrence with a wide variety of treatments. Many patients are disappointed by an initial unsuccessful treatment and fail to return for further therapy until the skin problem has become quite conspicuous. A simple treatment with few side effects and good acceptance remains an important goal. STUDY DESIGN/MATERIALS AND METHODS: Fifteen patients with a total of 33 xanthelasma lesions, were treated by an erbium:YAG laser. The follow-up period of observation was between seven and twelve months. RESULTS: All lesions were removed without hyperpigmentation or scarring. CONCLUSIONS: The erbium:YAG laser represents an effective means for treating xanthelasmas with few side effects.

Adult↗

Mid-infrared erbium:YAG laser ablation of bone: the effect of laser osteotomy on bone healing.

A comparative study was undertaken in rabbit tibiae to assess the healing of bone in response to osteotomies by a mid-infrared erbium: YAG (2.94 microns) laser or a mechanical saw. Laser parameters necessary for osteotomy were shown to produce deep cuts with sharp edges and no gross charring or burning of adjacent bone. However, it was noted histologically that there was a delay in healing of the laser osteotomies as compared to saw osteotomies. This delay was caused by a microscopic zone of damage to bone adjacent to the laser cuts. It is concluded that, although the erbium: YAG laser may be a useful tool in orthopaedic surgery to ablate bone, under the conditions used in this study, there will be a delay in the healing process after laser osteotomy.

Animals↗

Effects of an erbium: YAG laser on ocular structures.

We evaluated the effects of the erbium:YAG laser (2.9 micron wavelength) on ocular structures. Energy was successfully transmitted through a fiberoptic bundle for intraocular and extraocular applications. The wavelength was strongly absorbed by ocular tissues, producing ablations with minimal thermal damage. Our results indicated that the erbium:YAG laser may have potential uses as a photoablative tool to reshape the corneal surface and as a surgical knife.

Animals↗

Experimental studies on the suitability of the erbium laser for stapedotomy in an animal model.

Animal experiments in mature guinea pigs were devised to determine whether and to what extent inner ear damage can be caused by in vivo use of the erbium laser for stapedotomy. The present study examined the laser effect in connection with perforation of the basal convolution of the cochlea and subsequent application in the opened cochlea. Acoustic evoked potentials as compound action potentials (CAP) were recorded for changes in inner ear function. Findings demonstrated that five applications of the erbium:YSGG (yttrium-scandium-gallium-garnet) laser (energy, 85 mJ/pulse; energy density, 36 J/cm2) were needed to create a footplate perforation of 500-600 microns and did not lead to CAP alteration in any animal (n = 20). An increase of the repetition rate from 1 to 5 Hz likewise caused no CAP alteration (n = 17). Application of high total energies in the open cochlea (n = 5) to determine the safety of the laser system for stapedotomy revealed that a 10-fold increase in the total energy required for adequate perforation led to irreversible CAP alterations and no CAP could be recorded at a 15-fold increase in total energy. In contrast, a 5-fold maximum increase in total energy caused no CAP alterations. These results demonstrate the safety of the Er:YSGG laser comparable to that of the CO2 laser for stapedotomy, supporting its utility as an alternative method for surgery.

Acoustic Stimulation↗

Long-term effect of erbium-YAG laser (2.9 microns) on the primate cornea.

An erbium-YAG (2.9 microns) laser was used in the primate eye to irradiate the anterior surface of the cornea in one group and the midstroma in another group after temporary lamellar keratectomy. The eyes were observed clinically up to a period of eight months, when the animals were sacrificed. The initial opacification of the cornea caused by the erbium laser application gradually disappeared over the observation period and was replaced by a faint haze. The healing process was faster in Group II (midstromal laser ablation). Some degree of flattening of the cornea after laser ablation was seen in both groups by photokeratoscopy. At the end of the observation period, the irradiated corneas demonstrated normal appearing corneal structure without significant damage to the corneal epithelium, stroma, or endothelial cells. Further experimental studies are needed to improve the laser delivery system and reduce the degree of corneal damage produced by long laser pulses.

Animals↗

Experimental erbium laser surgery in the guinea pig cochlea: its use in the study of afferent cochlear neurotransmitters.

Microiontophoretic techniques were used to examine the changes in activity of inner half cell afferents in the guinea pig following circumscribed penetration of cochlear bone with erbium:YSGG laser pulses. Neuronal responses to the application of the glutamate agonists N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) before laser use and after return to normal spontaneous activity were equivalent, implying total reversibility of the changes occurring. Suppression of laser-induced hair cell activity was possible with NMDA and AMPA receptor antagonists and lasted 10-15 min. These findings suggest a transmitter-related increase of neuronal activity. Our results show that use of the erbium laser in inner ear microsurgery might be possible with low risk if the amount of energy applied is kept under a safe limit of 10 J/cm2.

6-Cyano-7-nitroquinoxaline-2,3-dione↗

Erbium lasers in dentistry.

Erbium hard tissue lasers have the capability to prepare enamel, dentin, caries, cementum, and bone in addition to cutting soft tissue. The ability of hard tissue lasers to reduce or eliminate vibrations, the audible whine of drills, microfractures, and some of the discomfort that many patients fear and commonly associate with high-speed handpieces is impressive. In addition, these lasers can be used with a reduced amount of local anesthetic for many procedures. Today, these instruments have evolved from their initial use for all classes of cavity preparations to their ability for removing soft tissue, their usefulness in the disinfection of bacteria within endodontic canals, and most recently, as an alternative to the high speed handpiece for the removal of bone in oral and maxillofacial surgery. In addition, recent research has centered on the value of the erbium family of laser wavelengths in periodontics, including the removal of calculus.

Dental Restoration, Permanent↗

Erbium:YAG laser skin resurfacing.

The Erbium:YAG laser is a useful flexible tool for the surgeon interested in providing overall skin rejuvenation. With its unique wavelength, greater absorption, and less thermal injury, it can offer more precise ablation with greater safety and shorter healing times. All skin types as well as all body parts can safely be treated, from simple lentigines to deeper rhytides. The Erbium:YAG laser is an effective tool for complete skin rejuvenation. System specifications and parameters are reviewed along with pathology,uses, and techniques including postoperative care, risks, and safety profile.

Aged↗

The compensation of potential changes produced by trivalent erbium ion in squid giant axon with applied potentials.

The transmembrane potential of voltage-clamped squid giant axon is increased to compensate for a reduction in the rate of potassium channel kinetics when artificial seawater with trivalent erbium ion is substituted for artificial seawater. The additional potential required to produce an equivalent rise time is a measure of the potential shift produced by the erbium ions. When the kinetics of K+ channels are matched in this manner, the maximal K+ currents are larger for the larger transmembrane potential. This observation requires a functional separation of the open K+ channel and the voltage sensor for the gating mechanism of this channel.

Animals↗

Pulpal thermal responses to an erbium,chromium: YSGG pulsed laser hydrokinetic system.

PROBLEM: Laser systems are known to raise pulpal temperatures when applied to tooth surfaces. Dental biocalcified tissues can be cut with an erbium,chromium:yttrium-scandium-gallium-garnet laser-powered hydrokinetic system. This device is effective for caries removal and cavity preparation in vitro. Pulpal monitoring of temperature changes during hard tissue cutting by a hydrokinetic system have not been reported. OBJECTIVES: This study compared the effects of hydrokinetic system, dry bur, and wet bur tooth cutting on pulpal temperature. STUDY DESIGN: In vivo thermocouple intrapulpal measurements were made on cuspid teeth in anesthetized beagle dogs. In vitro measurements were made on extracted human molar teeth preserved in high-salt solution and later rinsed in phosphate-buffered saline (pH 7.4) to simulate in vivo conditions. The hydrokinetic system was compared with conventional air-turbine-powered bur cutting. The hydrokinetic system cuts and bur preparations were randomly made on the buccal surfaces at the cervical one third of the crown and extended until exposure of the pulp was confirmed clinically. RESULTS: Pulpal temperatures associated with the hydrokinetic system either showed no change or decreased by up to 2 degrees C. Wet bur preparations resulted in a 3 degrees to 4 degrees C rise. With dry bur preparations, a 14 degrees C rise in temperature was recorded. CONCLUSIONS: Under the conditions of this study, the erbium,chromium:yttrium-scandium-gallium-garnet laser-powered hydrokinetic system, when used for cavity preparation, had no apparent adverse thermal effect as measured in the pulp space.

Aluminum Silicates↗

Manufacture and properties of erythromycin beads containing neutron-activated erbium-171.

To evaluate the effects of a neutron activation radiolabeling technique on an enteric-coated multiparticulate formulation of erythromycin, test quantities were produced under industrial pilot scale conditions. The pellets contained the stable isotope erbium oxide (Er-170), which was later converted by neutron activation into the short-lived gamma ray-emitting radionuclide, erbium-171. In vitro studies indicated that the dissolution profile, acid resistance, and enteric-coated surface of the pellets were minimally affected by the irradiation procedure. Antimicrobial potency was also unaffected, as determined by microbiological assay. Neutron activation thus appears to simplify the radiolabeling of complex pharmaceutical dosage forms for in vivo study by external gamma scintigraphy.

Chromatography, High Pressure Liquid↗

The influence of three Erbium:YAG laser energies on the in vitro microleakage of Class V compomer resin restorations.

OBJECTIVES: To investigate the influence of three Erbium:YAG pulse energies (200 mJ, 240 mJ, and 300 mJ with a 100 mJ dentine finish) on the microleakage of Class V compomer restorations (Compoglass). DESIGN: In vitro study. SAMPLE AND METHODS: Sixty-one extracted human premolar teeth were randomly allocated to three groups (according to pulse energy). Each tooth hosted one test cavity prepared with one of the three Er:YAG pulse energies using a pulse repetition rate of 5 Hz and a pulse duration of 250 microseconds, and one control cavity prepared with a conventional diamond bur in a high-speed hand piece. Both cavities were placed at the cervical margin of the tooth and were restored and finished according to the manufacturer's instructions. Each tooth was then stored in 0.12% thymol solution at 37 degrees C for three months, before being thermocycled through water baths between 5 degrees C and 55 degrees C for 240 cycles. Microleakage was assessed using a methylene blue dye penetration technique and was quantified using a score 0 (none) to 4 (to and into the axial wall). The data was analysed using the Kruskal-Wallis and Mann-Whitney U-tests. RESULTS: Leakage was seen in all groups at both the dentine and enamel margins. There were no statistically significant differences in leakage (P < 0.05) at either the enamel or dentine margins, except for the 240 mJ lased enamel margins. This group performed significantly better than the enamel margins prepared with 200 mJ (P = 0.03) and the 300/100 mJ (P = 0.01) laser energies as well as the conventionally prepared enamel margins (P < 0.001). CONCLUSION: Cavity preparation with this Erbium:YAG laser did not influence the microleakage of Compoglass restorations adversely. Different pulse energies were required for optimum cavity sealing at the enamel and dentine margins and for different materials.

Bicuspid↗

Suction blister grafting for stable vitiligo using pulsed erbium:YAG laser ablation for recipient site.

BACKGROUND: Suction blister grafting was performed via a modified simple technique using a 20-mL syringe to create the donor graft and pulsed erbium:YAG laser ablation of the recipient site. METHODS: Two patients with stable vitiligo and one with postinflammatory depigmentation were studied. RESULTS: The grafts took well in all three patients and pigmentation was retained at 20 weeks. No complications occurred. CONCLUSIONS: The erbium:YAG laser is an ideal tool for creating graft recipient sites, given its precision in terms of width and depth of ablation. A 20-mL syringe can be used to create a blister of adequate size.

Adult↗

Efficacy of erbium YAG laser-assisted autologous epidermal grafting in vitiligo.

BACKGROUND: Of the various modalities of therapy available for the treatment of vitiligo, a combination of psoralen + ultraviolet A (PUVA) with autologous epidermal grafting appears to offer the best results. The erbium YAG laser can be used to prepare the recipient site in both punch grafting and suction blister grafting. METHODS: In this study 29 subjects, 26 with localized and three with generalized stable vitiligo, had received pregrafting PUVA and underwent further PUVA starting 2 weeks after surgery until maximal pigmentation was achieved. The erbium YAG laser was used on 16 subjects; the recipient site for punch grafting was prepared with laser and minigrafts harvested by manual punch were placed into the prepared sites. For suction blister grafting, the site was dermabraded with a laser and the harvested blister roof (created using suction apparatus) was transplanted on to the site. RESULTS: More than two-thirds (68.75%) of the subjects who were punch grafted using a laser showed repigmentation of more than 75%, but only one-half of those who underwent conventional punch grafting showed a similar response. All subjects with laser-assisted suction blister grafting showed a good response, compared with only 60% of those who underwent conventional suction blister grafting. CONCLUSIONS: The results obtained with laser-assisted grafting are more satisfactory than those achieved with conventional grafting techniques. We found that the repigmentation zones are larger (up to 9 mm in the former vs. 3 mm in the latter) and cobblestoning does not occur with laser-assisted grafting. Also, the procedure is precise, relatively atraumatic and can be performed rapidly even when covering vast areas.

Adolescent↗