Journal of Lasers in Medical Sciences
Volume:1 Issue: 1, Autumn 2010

Introuduction: The aim of this in-vitro study was the evaluation of temperaturechanges due to irradiation of two different lasers used for the reduction of dentinalhypersensitivity and their effect on the pulp damage. The study was done for twodentin thicknesses. Twenty intact extracted third molars were prepared by longitudinal ground sectioning for 1 and 2 mm dentin thicknesses while a thermocouple was positioned at the inner surface of the dentin disk. Thermal evaluation was assessedby a KJT digital thermometer. During the test, the data produced by the thermometerwas transferred and logged into a PC via RS232 serial port. CO2 laser (Ultra pulse,50W, 100μsec, Spot size: 0.5 mm) and Er,Cr;YSGG laser (Free-running pulse mode,0.25W, 140μsec, 12.50 milli-joules) irradiations were randomly performed upon thedentin surfaces. The collected data was analyzed by two-way ANOVA test. The mean temperature rise in 1mm dentinal thickness was 8.57°C which was significantly higher than 3.63°C in 2mm dentin thickness (P<0.001) and higher than the threshold temperature for pulp damage; however, no significant difference wasnoted between the two lasers (P=0.355). After removing the CO2 laser, the temperature decreased to the initial level faster than the time needed for Er,Cr;YSGG laser (44.47°C versus 62.82°C)(P<0.001). In other words, in both lasers the temperature decrease in 2mm dentinal disc was faster than 1mm dentinal disc. The temperature rise due to both lasers for 1mm of dentinal thickness was in excess of safe limit for the tissue and it would probably result in pulpal damage. In the case of 2mm dentinal thickness, the temperature rise was not higher than the safe limit and it would not damage the pulp in clinical conditions.

Low level laser therapy (LLLT) is gaining acceptance in clinicalapplications. For example, it is used as therapeutic modality in the repair of diabeticfoot ulcer when conventional therapy was not effective, separately. The aim of thisstudy is to determine the effect of local and intravenous LLLT for the healing ofdiabetic foot ulcer. This study contains 74 diabetic foot-ulcers which were prone to resistance to conventional therapy. Different stages of diabetic foot are includedin this study. The wounds irradiation are performed by the combination therapy of650 nm and 860 nm laser, with the total energy density of 3.6 J/cm² plus intravenouslaser therapy (IVL) with 2.5 MW, 650 nm laser used for 30 minutes. All woundshave been photographed from equal distance, before and after treatments, and allthe wounds were staged by a surgeon who was disinterested and neutral about theeffects of the laser therapy. Her judgments were based on the visual assessments ofthe wounds. All the mathematical and statistical analysis is based on the descriptivestatistics which, is done by the SPSS 16 in the result of this study; 62.2% (Forty-six out of the 74 ulcers) completely healed, 12.2% (Nine in numbers) healed more than 50%, 8.1% (Six in numbers) healed less than 50%, 5.4% (Four in numbers) not healed,12.2% (Nine in numbers) did not continue their treatment (less than 5 sessions of Laser therapy). Excluding, the wounds in stage 5, more than 80% of each stage’s wound, completely healed more than 50%, with in 2 months duration. In this study, we definitely can express that, all the Patients received some degrees of healing, during their laser receiving treatments. The combined local and intravenous LLLT promote the tissue repairprocess of diabetic foot ulcer. In this multi-disciplinary method, we achieved aremarkably shorter mean healing time of two months, compared with other reportedstudies with healing time of three to six months.

No modality has been identified as the treatment of chice for treating common warts. Cryothearpy and pulsed-dye laser (PDL) are among common modalities for treating these lesions. The aim of this study was to compare pulsed dye laser with cryotherapy in terms of efficacy and complications.Matherial & Of a total of 46 patients enrolled in this study, 7 patientswithdrew the study, 20 patients underwent cryotherapy and 19 patients underwentPDL. Patients underwent a maximum of 4 therapeutic sessions at 3-week intervalsin both groups. They were assessed for the remission rate (complete and partial),side effects and recurrence rate in each session and 1 month after termination of thetreatments. At the end of the study complete remission was achieved in 37.8% of patients in cryotherapy group and in 52.3% of patients in PDL group. This difference wasn’t statistically significant (P=0.229), though after first and second sessions of treatment complete and excellent partial remission occurred more in PDL group with significant difference (P=0.007 and P=0.021). Pain and bulla formation occurred statistically higher in cryotherapy group (P=0.002 and P=0.001). Other complications were rare in both groups. In terms of efficacy, we couldn’t demonstrate the superiority of pulseddye laser therapy to cryotherapy in treating common warts. Both methods were safe for long-term complications but PDL was much safer for short-term complications.

Transurethral resection of prostate (TURP) is the most common urological operation performed. Regarding the complications of this surgery, studies are looking for alternative endoscopic techniques in order to reduce risk of complications. Use of high energy lasers is the most promising method for managing patients with benignprostate hyperplasia (BPH). In this study, we evaluated the effect of homemade KTPlaser on resected prostate adenoma after open prostatectomy. A total of forty resected prostate adenoma by open prostatectomy, assigned in to the study groups. One part of specimens without any intervention was sent to the pathology department and the rests divided to four KTP dose response groups (10 patients in each group). The prostate specimens were ablated by KTP laser in one, two, three, and four sessions according to their number of subgroups.Prostate tissue was irradiated by 5-watt KTP laser for 15 seconds in each stage. Allprostate specimens ablated with laser were sent to pathology for evaluation of tissueablation capacity and tissue penetration depth. Mean age of the participants was 73.25 ± 6.8 years with mean serum level PSA of 3.65 ± 2.1 ng/dl. 1 to 2 mm of the tissue was ablated at each session of laseradministration. In pathologic examination, 0 to 2 mm of tissue destruction withdisappearance of nuclei of the cells, basophilia of the stroma, and damaged tissue(cutter like effect) were witnessed. Findings were compatible with burn effect. KTP laser prostatectomy is a safe and effective procedure with lowrisk of complications in which bladder outlet obstruction symptoms will relieve.According to our study, extra penetration of prostate tissue during laser irradiationis rare. This finding could be suggestive this theory that KTP laser has little risk ofcapsule perforation.

Carpal Tunnel Syndrome (CTS) is the most common compressiveneuropathy. Several surgical and nonsurgical treatments have been proposed for thissyndrome, but there is no consensus regarding the prioritization of the suggestednonsurgical treatments. The goal of this study was to compare the long term effectsof laser therapy versus local corticosteroid injection in the treatment of CTS. During this single-blind randomized clinical trial, 65 handswith mild or moderate CTS were divided randomly into two groups. One groupreceived local corticosteroid injection (Hydrocortisone 50 mg) and the other receivedlow level laser therapy (20J/cm² in 11 seconds/session for each of 5 points, 775nm,10 sessions and 3sessions/week). Furthermore, wrist splints with extension degreeof 0° (neutral position) were prescribed simultaneously for 6 weeks in each group.Pain severity and electrodiagnostic measurements were compared from before to 10months after completing each treatment. Data were analyzed with SPSS 11.5 softwareand parametric tests. Generally, the mean age of patients was 43.9 years, duration of pain was 7.4 months, male to female ratio was 1:3, pain severity using Visual Analogue Scale(VAS) was 6.1 cm, and functional status measure was 15.5. The severity of the diseasebased on electrodiagnostic studies was 43.2% mild (41.2% in injection group and 45.2%in laser therapy group) and 56.8% moderate. The electrodiagnostic characteristicsof the median nerve prior to treatment were included mean sensory peak latency of4.3ms, mean sensory amplitude of 23.5μv, mean motor onset latency of 4.3ms andmean motor amplitude of 4.6mv. There was no meaningful difference between twogroups regarding the demographic characteristics and electrodiagnostic measures(p>0.05). Ten months after treatments, the mean of pain severity was decreased 1.9cmin injection group and 1.7cm in laser therapy group, the mean of median sensorypeak latencies was decreased 0.4ms in injection group and 0.25ms in laser therapygroup and the mean of motor onset latencies was decreased 0.15ms in both groups,with no significant difference between the observed treatments variables (P>0.05).The severity of disease based on electrodiagnostic studies became 32.4% normal,23.5% mild, 41.2% moderate and 2.9% severe in the injection group and 38.7% normal,22.6% mild, 35.5% moderate and 3.2% severe in the laser therapy group. There wasno meaningful difference between two groups regarding the changes in the painseverity, functional status and electrodiagnostic measures. Low level laser therapy can be as effective as local injection in reducing pain and severity of disease (based on electrodiagnostic medicine classification) in patients with mild and moderate CTS even in long term (after 10 months).

A hypertrophic scar is defined as an excess healing response that is a dilemma forphysicians. Several therapies are available: intralesional corticosteroids, topicaltreatments, cryotherapy, surgery, radiation, silicone gel dressing and laser therapy.Pulsed-dye, Nd-Yag and CO2 lasers have been used for treatment of keloids andhypertrophic scars but recurrence is common. Recently Low-Level Laser Therapy(aluminum-gallium-arsenide (AlGaAs) Diode 980nm, red light (Mustung, KLO4,Helium Neon 630 nm) and blue light LED lasers have been used for closure ofwounds. The aim of this report is to show the effectiveness of these lasers for thetreatment of a hypertrophic scar on the forearm of a 40 year-old woman due toburning by gas explosion.