ISSN:1044-5471    

DOI:10.1089/clm.2000.18.1

年代:2000

数据来源: MAL

摘要:

ABSTRACTObjective: A study was performed to evaluate the use of native fluorescence imaging to detect in situ molecular changes.Summary background data: There is no ideal noninvasive method to monitor molecular changes in a local region at a laser weld joint without removing a section of tissue for histological examination.Methods: Two sections of animal skin were welded together border to border using a Ti:sapphire laser beam (800 nm). Fluorescence imaging was performed on the cross section of the welded site at specific emission wavelengths (Àc) for collagen at 380 nm and for elastin at 450 nm using excitation wavelengths (Àe) of 340 nm, and 380 nm, respectively.Results: A reduction of the collagen and elastin emission was observed in the fluorescence images of the welded region. These results were confirmed with histology using picrosirius red F3BA under polarized light and orcein stains.Conclusion: Optical spectroscopic imaging offers a new noninvasive detecting method for microscopic evaluation of laser tissue weldin

ISSN:1044-5471    

DOI:10.1089/clm.2000.18.3

年代:2000

数据来源: MAL

摘要:

ABSTRACTObjective: We used SEM-EDX and the Vickers hardness test to compare the penetration and hardness of silver resulting from use of either (i) pulsed Nd:YAG laser or (ii) iontophoresis, after root canal wall shaping using the standard method of coating with 38% Ag(NH3)2F solution.Summary Background Data: There have not been any reports of penetration and hardness following the application of Ag(NH3)2F solution together with laser or iontophoresis.Methods: We used 21 extracted human single-rooted teeth randomly divided into three groups. Group 1 was coated with Ag(NH3)2F, Group 2 was irradiated with a Nd:YAG laser after coating with Ag(NH3)2F solution, and Group 3 was iontophoresised after coating. Then we observed the permeability of silver through the root canal wall using SEM-EDX.Results: The results show that iontophoresis after coating with Ag(NH3)2F solution (Group 3) resulted in the greatest and deepest penetration of silver into the root canal wall. There was no significant difference between teeth in Groups 1 and 2. For the hardness test, the 21 teeth were tested using SEM-EDX test, 7 untreated teeth were used as a control. The results show that Group 2 (laser treatment) teeth were the hardest.Conclusion: We therefore propose that root canals should be treated using irradiation with an Nd:YAG laser that has been coated with Ag(NH3)2F solution and that this method provides better results than either iontophoresis after coating, or coating alone.

ISSN:1044-5471    

DOI:10.1089/clm.2000.18.9

年代:2000

数据来源: MAL

摘要:

ABSTRACTObjective: This single case report (ABA design) was undertaken as a preliminary investigation into the clinical effects of low intensity laser upon venous ulceration, applied to wound margins only, and the potential relevance of wound debridement and wound measurement techniques to any effects observed.Methods: Ethical approval was granted by the University of Ulster's Research Ethical Committee and the patient recruited was required to attend 3 times per week for a total of 8 weeks. Treatments were carried out using single source irradiation (830 nm: 9 J/cm2, CB Medico, Copenhagen, Denmark) in conjunction with dry dressings during each visit. Assessment of wound surface area, wound appearance, and current pain were completed by an independent investigator. Planimetry and digitizing were completed for wound tracings and for photographs to quantify surface areas. Video image analysis was also performed on photographs of wounds.Results: The primary findings were changes in wound appearance, and a decrease in wound surface area (range 33.3—46.3%), dependent on the choice of measurement method. Video image analysis was used, but rejected as an accurate method of wound measurement. Treatment intervention produced a statistically significant reduction in wound area using the C statistic on digitizing data for photographs (at Phase one only;Z= 2.412;p<0.05). Wound debridement emerged as an important procedure to be carried out prior to measuring wounds. Despite fluctuating pain levels recorded throughout the duration of the study, VAS scores showed a decrease of 15% at the end of the study. This hypoalgesic effect was, however, statistically significant (using the C statistic) at Phase one only (Z= 2.554;p<0.05).Conclusions: Low intensity laser therapy at this dosage, and using single source irradiation would seem to be an effective treatment for patients suffering venous ulceration. Further group studies are indicated to establish the most effective therapeutic dosage for this and other types of ulceratio

ISSN:1044-5471    

DOI:10.1089/clm.2000.18.15

年代:2000

数据来源: MAL

摘要:

ABSTRACTObjectives: The aims of this study were to investigate the capability of removing the filling materials or broken files from root canals with pulsed Nd:YAG laser irradiation at three parameters, and to evaluate the temperature rises on root surfaces and morphological changes of root canal wallsin vitro. Summary Background Data: There has been no report on removing the filling materials and broken instruments from root canals with laser irradiation.Materials and Methods: Thirty-six extracted human incisors were divided into two groups of 18 each. Eighteen root canals were shaped and obturated with gutta-percha and root canal sealer. In another 18 specimens, 3-mm long fractures of files were performed intentionally during root canal preparation. A pulsed Nd:YAG laser irradiation was performed repeatedly at three parameters of 1,2, and 3 W to remove the filling materials or file fragments. Temperature rises on root surfaces during laser irradiation were measured by thermography, and the remaining of obturated materials and morphological changes of root canal walls were evaluated by stereoscopy and scanning electron microscopy.Results: In more than 70% of the teeth, the obturated materials were completely removed by laser, and in more than 55% of the teeth, the broken files were successfully removed. Temperature rises ranging from 17°C to 27°C were measured from 6 to 11 repeated times.Conclusion: These results demonstrated that a pulsed Nd:YAG laser irradiation has the capability of removing the obturated materials in root canals and is useful for removing the broken files in same if the counter-measure reducing the temperature rise is performe

ISSN:1044-5471    

DOI:10.1089/clm.2000.18.23

年代:2000

数据来源: MAL

摘要:

ABSTRACTObjective: To determine (1) if familial and genetic factors play a role in the genesis of disc herniation, (2) the incidence of multiple disc herniations, (3) the incidence of disc reherniation in patients treated with standard laminectomy and discectomy, and (4) to construct a hypothesis that best explains all three.Summary Background Data: It is known that there is a substantial incidence of disc herniation in first order relatives of patients with herniated nucleus pulposa (HNP), that multiple disc herniations are not uncommon, and that disc reherniations and repeat operations after laminectomy and discectomy range from 5 to 37%. Also, there is a recent report of a genetic defect leading to defective cross-linkage of collagen strands in patients with HNP.Methods: Using the questionnaire method, a group of the author's patients with documented HNP treated with percutaneous laser disc decompression (PLDD) was surveyed as to the existence of known disc herniations among first order relatives. Analysis of the author's series of 621 patients with HNP disclosed the incidence of multiple disc herniations. A comprehensive literature search provided data on reherniations and reoperations following laminectomy and discectomy.Results: In 174 respondents, the number with first order relatives who had HNP was 74 (or 43%). This compares with the national incidence of HNP of 1.7%. The statistical significance yields aP= 0.0001. In the 621 patients with known HNP, the number who had more than one herniated disc was 236 (or 38%). In multiple reports in the literature, the incidence of reherniation after laminectomy and discectomy ranged from 5 to 37%.Conclusions: The simplest hypothesis explaining all of the above is that intervertebral disc herniation is due to an acute or subacute increase of intradiscal pressure acting against a congenitally weak anulus fibrosus and posterior longitudinal ligament, and therefore laminectomy and discectomy, by further weakening these structures, may be counterproductive.

ISSN:1044-5471    

DOI:10.1089/clm.2000.18.29

年代:2000

数据来源: MAL

摘要:

ABSTRACTPurpose: The purpose of thisin vitrostudy was to compare caries resistance of sound human enamel following argon laser (AL) irradiation, as well as, combinations of topical fluoride foams and AL irradiation.Methods and Materials: Thirty extracted human teeth were sectioned into four buccal windows and assigned to one of the following treatment groups: (1) no treatment/control; (2) low fluence (11.5 J/cm2) AL irradiation for 10 seconds; (3) 1.23% APF foam for 4 minutes followed by low fluence AL irradiation; (4) 2.0% NaF foam for 4 minutes followed by low fluence AL irradiation. Caries-like lesions were created by submerging the teeth in ten Cate solution (pH 4.5). Following a 96-hour exposure period, 100 μm longitudinal sections were prepared for polarized light evaluation. Visilog 5.1.1. image analysis software was used to obtain quantitative lesion depths. The Scheffe F-test was used to compare the lesion depths for each of the four treatment groups.Results: Lesion depths were: 16.1 ± 6 μm for control; 13.7 ± 4 μm for AL irradiation alone; 12.1 ± 4.3 μm for 1.23% APF foam before AL irradiation; and 11.4 ± 5.9 μm for 2.0% NaF foam before AL irradiation. Significant difference (p<0.05) was found between the control group and the 2.0% NaF foam before AL irradiation group. AL irradiation alone reduced lesion depth by 15% compared with the control lesion. When AL irradiation was combined with 1.23% APF foam treatment, lesion depth decreased by 25% compared with control lesions, and by 29% when combined with 2.0% NaF foam.Conclusion: Combining AL irradiation and 2.0% NaF foam treatment significantly enhances the resistance of sound enamel to anin vitrocariogenic c

ISSN:1044-5471    

DOI:10.1089/clm.2000.18.33

年代:2000

数据来源: MAL

ISSN:1044-5471    

DOI:10.1089/clm.2000.18.37

年代:2000

数据来源: MAL

ISSN:1044-5471    

DOI:10.1089/clm.2000.18.39

年代:2000

数据来源: MAL