摘要:

ABSTRACTLow-power laser (LL) irradiation causes biological effects such as analgesia. Cerebrospinal fluid (CSF) and blood immunoreactive β-endorphin (Iβ-E) delivery is involved; however, there are no opioid dose–response curves for different laser energy densities (ED) irradiation. In this work we try to determine dose–response curves for single and multiple HeNe and GaAs LL irradiation in both CSF and plasma Iβ-E contents, irradiating peripheral tissues. Single irradiation with HeNe or GaAs LL did not modify CSF Iβ-E concentrations. An ED of 12 J/cm2caused a statistically significant (p<0.001) tendency to decrease the opioid peptide using the HeNe laser. Blood Iβ-E concentrations grow incrementally in single laser EDs (HeNe and GaAs). The most effective EDs were 9 to 10.8 J/cm2; higher EDs decreased the biological response. As a result of chronic stress suffered in mutiple LL irradiation (multiple intraperitoneal chloral hydrate administration is involved), CSF and blood basal Iβ-E concentrations increased. A tendency for Iβ-E to decrease (normalizing) in CSF and blood followed mutiple HeNe and GaAs LL irradiation using an ED of 10.8 J/cm2. A higher ED was less effective. GaAs LL not only failed to normalize, but increased blood opioid concentrations; however, HeNe LL irradiation behaved

ISSN:1044-5471    

DOI:10.1089/clm.1994.12.1

年代:1994

数据来源: MAL

摘要:

ABSTRACTThe mechanism of postangioplasty vasospasm is uncertain. It was postulated that alterations in arachidonic acid metabolism might contribute to spasm or acute occlusion of the treated coronary artery. In this study, coronary arterial plasma prostacyclin and thromboxane were monitored before and after argon laser ablations in canine coronary arteries (by standard radioimmunoassay of the metabolites 6-keto PGF1αand TXB2). Plasma 6-keto PGF1αlevels were unchanged or slightly increased (post/pre: 0.95 ∼ 1.82) in all cases after intracoronary laser ablations. However plasma TXB2levels were not increased (post/pre: 0.78 ∼ 1.44) in cases of uncomplicated laser ablations, but were remarkably increased (post/pre: 3.34 ∼ 6.64) in cases with laser complications, such as perforation or thermal vascular injury. These results suggest that uncomplicated laser ablations in the coronary arteries may not contribute to coronary spasm and acute coronary artery occlusion from the aspect of vessel wall arachidonate met

ISSN:1044-5471    

DOI:10.1089/clm.1994.12.7

年代:1994

数据来源: MAL

摘要:

ABSTRACTThis clinical study examined the pulpal safety of selected CO2laser hard tissue applications. A total of 187 hard tissue procedures were performed on 54 patients. The mean period of follow-up following laser treatment was 13.5 months (range 2–24 months). The procedures included etching (n= 96), desensitizing (n= 56), laser-enhanced fluoride (n= 28), treatment of external resorption (n= 4), and pulp capping or pulpotomy (n= 3). Only the latter two procedure types were performed with anesthesia. The total irradiation received during these procedures ranged from 2 to 12 J. No patients complained of sensation or discomfort during any procedure. Pulp vitality was maintained in all teeth, and no instances of postlasing thermal sensitivity or pulpitis were reported. These results indicate that pulp vitality can be maintained provided that conditions of irradiance are controlled carefully to minimize thermal effect

ISSN:1044-5471    

DOI:10.1089/clm.1994.12.11

年代:1994

数据来源: MAL

摘要:

ABSTRACTThe purpose of this study was to determine the power and time parameters for an argon laser that would result in the removal of pulpal tissue without excessively elevating the external temperature of the root. External temperatures were measured by attaching thermistors to the surfaces of the teeth at the cemento-enamel junction (CEJ) areas and at the root apices. Results indicate that a 1-W power setting with a pulse duration of 0.1 sec and a 1 sec interval between pulses produced a mean temperature rise of 0.89 ± 0.27°C at the cemento-enamel junction area and a mean temperature increase of 2.04 ± 0.47°C at the apex. A 2-W power setting with a 0.1 sec pulse duration and a 1 sec interval between pulses resulted in a mean temperature increase of 1.58 ± 0.45°C at the CEJ and a mean temperature rise of 2.59 ± 0.20°C at the apex. Based upon the results of this study, it was concluded that an argon laser operating at 1 or 2 W of power with a 0.1 sec pulse duration could be used to remove pulpal tissue without creating an excessive increase in the external temperature of th

ISSN:1044-5471    

DOI:10.1089/clm.1994.12.17

年代:1994

数据来源: MAL

摘要:

ABSTRACTMolar teeth in male rats were used in this study to assess the effects of enamel surface treatments of pulp survivability. The occlusal surfaces of the first and third molars in each quadrant were treated with an Nd:YAG laser (Pulsemaster, Incisive Technologies, Inc.) using a 300-μm contact tip fiber, in a figure-8 motion, for a 30 sec ablation time. The second molars were not treated. Energy parameters/animal were as follows: (1) 0.6 W, 30 mJ energy, and 20 Hz, (2) 1.2 W, 30 mJ energy, and 40 Hz, (3) 1.8 W, 30 mJ energy, and 60 Hz, (4) 2.4 W, 30 mJ energy, and 80 Hz, (5) 0.6 W, 60 mJ energy, and 10 Hz, (6) 1.2 W, 60 mJ energy, and 20 Hz, (7) 1.8 W, 60 mJ energy, and 30 Hz, (8) 1.0 W, 100 mJ energy, and 10 Hz, and (9) 2.0 W, 100 mJ energy, and 20 Hz. Animals were sacrificed at two time periods (1 and 6 weeks, postoperatively). SEM analysis of enamal was performed at 2000 × magnification to observe the parameter difference in surface quality. Microscopic examination of the histological samples was accomplished at 250 × magnification. Surface analyses of tooth structure revealed a wide dispersion of enamel roughness, ranging from slightly etched to moderately cavitated. Power levels above 2.4 W exhibited significantly more roughness than lower energy parameters. Efforts were made to correlate the pulp biology effect with enamel surface condition to determine a safe threshold for survivability of the pulp tissue. The clinical implications of these results indicate that a high-rep rate Nd:YAG laser can induce enamel surface changes without causing concomitant pulp damage. More importantly, a precise threshold can be defined to express the nature of utilizing high-rep rate lasers with exceptionally low-energy density leve

ISSN:1044-5471    

DOI:10.1089/clm.1994.12.21

年代:1994

数据来源: MAL

摘要:

ABSTRACTArgon laser therapy of superficial pigmented lesions in both young and old people is associated with a risk of complications including delayed wound closure and hypo/hypertrophic scarring. Problems may also occur after treatment of lesions located on the eyelid. To minimize the risk of these problems coagulation of deep tissue should be avoided. We discuss a technique using mercurochrome, a red-colored compound that absorbs the blue and green lines of the argon laser, as a barrier for the irradiated light that eliminates these complications and we provide probable reasons for this technique's effectiveness.

ISSN:1044-5471    

DOI:10.1089/clm.1994.12.27

年代:1994

数据来源: MAL

摘要:

ABSTRACTThis study investigated the effects of low-power laser irradiation on the rabbit cornea. Making use of the immune reaction common in rabbits, the Arthus phenomenon, we injected all rabbits with complete Freund's adjuvant containing inactivated mycobacterium twice to stimulate B cell activity, then injected them two more times with incomplete Freund's adjuvant containing human serum to stimulate T cell activity. One week after the experiment initiation we applied 0.5 ml of human serum intracorneally to both eyes in all rabbits. Sickle-shaped turbidity was observed immediately. The rabbits were then divided into control (47) and test groups (10) and the test group received low-power laser treatment using the HeNe laser at 5 mW for 2 min daily. Treatment was applied to only one eye. We observed significant changes in the treated group including increased vascular sprouting, longer duration of neoangiogenesis, and creation of longer vessels in the laser-treated group. Vascular sprouting took place 24 hr after irradiation in the test group and from 5–8 days later in the control group. Vascularization ceased on day 8 in the control animals: control animals' corneas appeared avascular from day 12 on. In the test group, alternatively, the vessels could still be seen 14 days after laser irradiation. Vessels were 8 mm in irradiated animals but only 4 mm in the control animals. Based on our study we suggest that irradiation of an Arthus phenomenon induced in the rabbit's cornea with low-power laser is able to influence neoangiogenesis positivel

ISSN:1044-5471    

DOI:10.1089/clm.1994.12.31

年代:1994

数据来源: MAL

摘要:

ABSTRACTIn Hungary, where lasers are few and the economy dictates wise use of those that exist, it is important to emphasize the versatility of a laser to support the cost and maintenance of it. This study indicates that both the CO2and Nd:YAG lasers can be effective as treatment for vascular malformations of the skin. We discuss treatment of a nevus flammeus on one patient and treatment of a polypoid hemangioma on another using both lasers and we compare the results of the two modalities.

ISSN:1044-5471    

DOI:10.1089/clm.1994.12.35

年代:1994

数据来源: MAL

ISSN:1044-5471    

DOI:10.1089/clm.1994.12.39

年代:1994

数据来源: MAL

ISSN:1044-5471    

DOI:10.1089/clm.1994.12.49

年代:1994

数据来源: MAL