Antimicrobial Photodynamic Therapy: An Effective Alternative Approach to Control Bacterial Infections

Hassan Mahmoudi, Abbas Bahador, Maryam Pourhajibagher, Mohammad Yousef Alikhani

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 154-160

Introduction: The purpose of this review was to evaluate the available literature for in vitro and in vivo effectiveness of antimicrobial Photodynamic therapy (aPDT) in the field of bacteriology.
Methods: A review of the relevant articles carried out in PubMed and Scopus to determine the efficiency of aPDT used in the reduction of microbial infection. Thirty-one relevant documents retrieved from PubMed, Scopus by inserting “antimicrobial photodynamic therapy” and “bacterial infection” and “photodynamic therapy” keywords.
Results: According to different results, aPDT can be used as an adjuvant for the treatment of infectious diseases. The use of photosensitizer methylene blue, toluidine blue O (TBO), indocyanine green with light diode laser centered at (630±10 nm) and (650±10 nm) wavelengths have been shown to have significant results for the treatment of infectious diseases and bactericidal properties
Conclusion: These findings suggest that, aPDT can be an efficient method in the treatment of localized and superficial infections.

The Effect of Quorum-Sensing and Efflux Pumps Interactions in Pseudomonas aeruginosa Against Photooxidative Stress

Parizad Rezaie, Maryam Pourhajibagher, Nasim Chiniforush, Nava Hosseini, Abbas Bahador

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 161-167

Resistant infections essentially cause mortality in a burn unit. Several bacteria contribute to burn infections; among these, Pseudomonas aeruginosa majorly contributes to these infections revealing significant drug resistance. Similar to other bacteria, P. aeruginosa reveals various mechanisms to attain highest pathogenicity and resistance; among these, efflux pumps and quorum sensing are crucial. Quorum sensing enables effective communication between bacteria and synchronizes their gene expression resulting in optimum effect of the secreted proteins; alternatively, efflux pumps increase the bacterial resistance by pumping out the antimicrobial factors as well as the QS signals and precursors. Of recent, increasing episodes of drug resistance led to new findings and approaches for killing pathogenic bacteria without inducing the drug-resistant species. Photodynamic therapy (PDT), considered as an adjuvant and innovative method for conventional antibiotic therapy, is a photochemical reaction that includes visible light, oxygen, and a photosensitizer (PS). In this therapy, after exposure to visible light, the PS generates reactive oxygen species (ROS) that are bacteriostatic or bactericidal. Furthermore, this oxidative stress can disrupt the coordination of gene expression and alter the bacterial behavior. Considering the fact that the adaption and several gene expression patterns of microorganisms within the biofilm make them notably resistant to the recent antimicrobial treatments, this study aimed to emphasize the relationship between the efflux pump and QS under oxidative stress and their role in P. aeruginosa’s reaction to PDT.

Repair of massive and irreparable rotator cuff tear using arthroscopic method

Ardeshir Alidousti, Fateme Mirzaee, Fateme Bahramian, Zohreh Zafarani, Naeeme Mirzaei, Hamidreza Aslani

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 168-176

Rotator cuff tear is one of the major causes of shoulder pain and disability, especially in elderly patients over 60 years. Improvement of performance and reduction of pain hardly occur in patients with contracted rotator cuff tear. Despite therapeutic advances, yet there are many discussions over choosing the best type of treatment for major rotator cuff tear. Complete treatment of massive rotator cuff tear continues to be a challenge in the shoulder surgery. Treatment options have changed in compassion with traditional treatment methods in open or arthroscopic debridement surgery with or without decompression. Recently, many treatments have been introduced, including a range of non-surgical treatments, acromioplasty by debridement, biceps tenotomy, tuberoplasty by biceps tenotomy, minor repair, mini-open rotator cuff repair, arthroscopic rotator cuff, muscle movement, reverse shoulder arthroscopy, soft tissue reinforcement and hemiarthroplasty. Non-surgical massive rotator cuff control is typically assigned for patients with insignificant pain. This therapy functions by changing activities, proper use of steroid injections and physical therapy with an emphasis on the anterior deltoid exercises. But the main problem is the selection of the best treatment and making the final decision. In general, in the arthroscopic morbidity, postoperative pain along with hospital stay is less and the operation has better cosmetic results. So this information and our results have prompted us to study a variety of rotator cuff treatment methods with a focus on the arthroscopic treatment.

Effects of laser and fluoride on the prevention of enamel demineralization: an in-vitro study

Nastaran Chokhachi Zadeh Moghadam, Bahman Seraj, Nasim Chiniforush, Sara Ghadimi

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 177-182

Introduction: Investigations have demonstrated that fluoride is an essential element in preventive dentistry. However, there are still controversies about the preventive effects of various kinds of laser. The aim of this study was to examine the effect of diode laser irradiation (810 nm) with or without fluoride therapy in the prevention of deciduous enamel demineralization.
Methods: Sixty deciduous molar crowns were randomly assigned to 6 groups: C: received no treatment; F: fluoride varnish application; 2L: 2 times diode laser irradiation; 4L: 4 times diode laser irradiation; F2L: 2 times laser irradiation over fluoride varnish; F4L: 4 times laser irradiation over fluoride varnish. Teeth in all groups were subjected to a pH-cycling process to produce artificial caries-like lesions.
Results: The analysis of variance (ANOVA) of microhardness values indicated a significant great effect for laser, fluoride, and the interaction of laser- fluoride on reducing the final microhardness value (P < 0.001). However, the 2L group was an exception. Despite the 4L group, it did not show a significant prevention of enamel microhardness loss (P = 0.125). These 2 groups exhibited different effects in the absence of fluoride (P2L-4L = 0.05) while in the presence of the fluoride varnish, no statistically significant difference was observed between them (PF2L-F4L = 0.257). Moreover, no statistically significant difference was observed between the laser-fluoride combination group and the fluoride group (PF2L-F = 0.133, PF4L-F = 0.926).
Conclusion: Our results suggest that fluoride varnish, diode laser, and their combination decrease the loss of the enamel microhardness value and potentially prevent deciduous enamel demineralization. However, the combination of laser and fluoride was not more effective than fluoride.

Surgical Management of Vesical Stones in Children: A Comparison Between Open cystolithotomy, Percutaneous Cystolithotomy and Transurethral Cystolithotripsy with Holmium-YAG Laser

Babak Javanmard, Morteza Fallah Karkan, Mohammadreza Razzaghi, Saleh Ghiasy, Arash Ranjbar, Amirhossein Rahavian

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 183-187

Introduction: Bladder stone in children is rare but is more common in developing countries. In recent years, the urologists have trend to minimal invasive approaches. The aim of this study, was to compare the outcomes of surgical bladder stone management in our single tertiary center.

Methods and materials: The 159 children younger than 18 years with vesical stones treated during January 2000 to January 2015 in Shohada e Tajrish hospital, Tehran, Iran that 146 subjects entered to the study. According to type of intervention, patients stratified to three groups. First group was included 80 patient’s that open cystolithotomy(OCL) was done for them, second group, 39 patients who underwent percutaneous cystolithotomy(PCCL)and third group,27 patients who treated by transurethral cystolithotripsy with holmium-YAG laser(TULL). Demographic data, operation time, hospital stay, and post operation complications were extracted and compared between groups.

Results: Mean age was 8.3±5.1 years (8.6±5.1, 6±4.2 years for boys and girls, respectively). Mean stone size was 2.76±1.07 cm that was not significant between three groups but it was larger in OCL group. Mean operative time was 29.15(±7.12) min that in separate, mean operative time in TULL was significantly higher than PCCL and OCL respectively (36.3±5.97, 30.54±5.27 and 26.06±6.32 min/P:0.000). Mean hospital stay in OCL group was 3.55±1 day that was higher than PCCL and TULL groups significantly (P=0.000).

Conclusion: based on our study, Ho:YAG lithotripsy is a safe with high success rate minimally invasive management method for children bladder calculi if proper equipment was available and done in expert hands.

Evaluation of Tooth Surface Irradiated With Erbium: Yttrium Aluminum Garnet and Carbon Dioxide Lasers by Atomic Force Microscopy

Sogol Saberi, Sooreh Seyedjabbari, Hossein Bagheri, Susan Mir Mohammad Rezaei, Sima shahabi

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 188-193

Introduction: T Laser irradiation of dentin surface can affect its surface topography and roughness. Atomic force microscopy (AFM) is among the most efficient tools for determination of surface topography of natural biomolecules in nano-scales. Surface roughness affects plaque retention especially in the cervical region. This study aimed to assess and compare the obstruction of dentinal tubules and dentin surface roughness after irradiation of erbium: yttrium aluminum garnet (Er:YAG )and CO2 lasers for treatment of dentin hypersensitivity (DH) .
Methods: Five disc-shaped samples measuring 3 mm in thickness were fabricated by horizontal sectioning of the cervical area of five extracted human molars using a low speed saw. Each disc was divided into 3 segments by a bur under water coolant. The three segments of each disc were placed on a glass slide. First segment: No intervention (control group). Second segment: Er:YAG laser irradiation (2940 nm, 50 mJ, 10 Hz and 0.5 W, 30 seconds) along with water coolant. Third segment: CO2 laser irradiation (10600 nm, 80 Hz, 0.3 W, 30 seconds) along with water coolant. After that, the surfaces underwent non-contact AFM. The diameters of dentinal tubules as well as surface roughness were then measured and statistically analyzed using repeated measures ANOVA.
Results: The surface roughness parameters (Ra, Rq) showed increased roughness after laser irradiation and this increase in roughness after Er:YAG laser application was significant compared to the control group (P = 0.048). However, CO2 laser caused no significant change in surface roughness. Also, after Er:YAG laser application, fewer open dentinal tubules were observed and the remaining open tubules had a smaller diameter.
Conclusion: Based on the results, Er:YAG laser irradiation obstructs the dentinal tubules and increases the dentin surface roughness. This increase in surface roughness can cause microbial plaque retention and increase the risk of caries and periodontal disease. Application of CO2 laser (compared to Er:YAG) lead to slight but clinically significant obstruction of dentinal tubules and surface roughness

Comparative Evaluation of the efficacy of Laser Therapy and Fibroblastic Growth Factor Injection on Mucosal Wound Healing in Rat Experimental Model

Maryam Allameh, Saeedeh Khalesi, Faezeh Khozeimeh, Elham Faghihian

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 194-199

Introduction: The aim of present study was to compare the effects of laser and bFGF treatment on operative wound healing in a rat model.

Methods: 66 male Wistar rats were employed in this study. 10millimeter surgical wound was created on buccal mucosa of each rat ,under anesthesia, and then the rats were divided into 3 groups of 22 each: 1- GF group (received subcutaneous injection of bFGF), 2- laser group (treated with low level laser irradiation) and 3- control group (received no treatment). On day 5 half of rats in each group and on day 10 the other half, were sacrificed. Then, samples were taken from rats' buccal mucosa for histological assay and scoring. The data was analyzed with Mann-Whitney test (α=5%).

Results: On day5 there was not any significant difference between GF and control group; however laser group showed delayed wound coverage clinically, compared to other groups(p<0.05). On day 10, histological examination demonstrated marked vascular granulation tissue in GF group. Collagen production was significantly prominent in laser group compared to GF treated samples (p=.004). Inflammation of granulation tissue in GF and laser groups was significantly less than that in control samples (p=.005 and .001, respectively). 

Conclusion: The components of wound matrix induced by GF and laser treatment were significantly different. Although bFGF or laser treatment of oral wounds, under conditions of present study, did not accelerated wound healing but showed some other notable effects on the quality of healing.

Comparison of Micro-Shear Bond Strength of Resin Cement to Zirconia With Different Surface Treatments Using Universal Adhesive and Zirconia Primer

Baharan Ranjbaromidi, Parnian Karimi Yeganeh, Sonia Oveisi, Negin Farahmandpour, Fahimeh Nouri

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 200-206

Introduction: Increased demand for metal free fixed partial denture in recent years led to the developing of all ceramic material with excellent mechanical properties. One of the most popular all ceramic is zirconia which shows poor bonding properties. Recently, universal primer contains of silane and phosphate monomer for bond to zirconia have been introduced. The aim of this study is determination of the best method for bonding to zirconia based on the selection of the correct primer, suitable adhesive and best surface pretreatment.
Methods: In this in vitro experimental study 16 sintered-zirconia blocks prepared in dimension of (18×6×2 mm) by CAD/CAM technology. Sample cleansed by ultrasonic device contain of 96% ethanol in 6 minutes, after air-drying, based on surface treatment randomly divided into 4 groups which each group divided into 2 sub-groups based on the use of a primer or universal bond: (1) no treatment: (a) cement + zirconia primer, (b) cement + universal bond. (2) Alumina pretreatment: (a) cement + zirconia primer, (b) cement + universal bond. (3) Cojet sand pretreatment: (a) cement + zirconia primer, (b) cement + universal bond. (4) laser pretreatment (a) cement + zirconia primer, (b) cement + universal bond. Composite disc prepared with condensation of composite resin in Tygon tube with integral diminution of 0.7 mm which cured for 40 sconds. Universal bond or zirconia primmer apply on the surface of the zirconia samples then cemented to composite disks by Panavia F2 according manufacture instructions. Micro-shear bond strength determined with universal testing machine. Failure mode assessed under stereomicroscope. Selected sample based on surface treatment evaluated under SEM. Data were analyzed using one-way analysis of variance (ANOVA).
Results: Comparison of the 4 surface treatment groups revealed a significant difference and the highest bond belonged to Cojet and the lowest one to laser group.
Conclusion: It seems that Universal Adhesive can to be considered as an alternative to bond to zirconia but the Cojet method is still required.

The Impacts of Low-Level Laser Therapy – A Complementary Treatment in the Management of Side Effects After Implant Surgery

Roya Safdari, Narges Pouremadi, Ehsan Talebzadeh, Arash Mottaghi, Shahram Amini, Abolfath Hossienzadeh, Bijan Movahedian Attar

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 207-211

Introduction: One of the most important medical applications of laser is low-level laser therapy (LLLT). In this method, laser radiation penetrates easily into the target tissue. The aim of this study was to investigate whether LLLT can reduce the side effects of advanced implant surgery.
Methods: In this triple-blind clinical trial, 30 patients aged 25 to 65 years were selected for implant insertion and divided into two groups. In the laser group, immediately after the surgery, 72 hours and 1 week after the surgery, the surgical site was irradiated with an 830 nm laser. The dose required for the laser therapy was 5 J/cm2. The degree of pain, facial swelling and wound healing were analyzed using statistical methods.
Results: Our results showed that at 12, 24, 48, and 72 hours after the surgery, the pain level was reduced in the laser group compared with the placebo group (P < 0.05). Swelling of the face was also significantly reduced 7 days after surgery in the laser group (P < 0.05). The investigation on the recovery conditions of the surgical site showed that on the 3rd, 7th and 14th days after the surgery, higher levels of wound healing have been achieved (P < 0.05).
Conclusion: Our results suggest that laser, as a complementary therapy; can be used to reduce the severity and duration of pain. Also, laser can reduce facial swelling and accelerate wound healing.

Effect of Low Level Laser Irradiation on the Function of Glycated Catalase

Hossein Mirmiranpour, Fatemeh Shams Nosrati, Seyed Omid Sobhani, Sina Nazifi Takantape, Ahmad Amjadi

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 212-218

Introduction: The aim of this work is to evaluate the effect of low level laser irradiation (LLLI), by lasers with different wavelengths, on glycated catalase enzyme in vitro experimentally. This is done by measuring the activity and structure properties of glycated catalase enzyme. The structure properties were evaluated with circular dichroism (CD) and fluoroscopy methods. Three continuous wave (CW) lasers in visible spectrum (λ= 450, 530, 638 nm) and a 100-ns pulsed laser in infrared spectrum (λ= 905 nm) were chosen for comparison. For the infrared laser, same effects have been investigated for different energy doses. The effect of photon energy (hυ) at different wavelengths was measured on activity, CD, and fluoroscopy properties of catalase, and compared with the control group [samples without irradiation]. The energy intensity of laser should not exceed 0.1 J/cm2. Experiments were performed on glycated catalase between 2 to 16 weeks after glycation of catalase. The LLLI effect has also been investigated on the samples, by comparing the catalase activity, CD and fluoroscopy for different wavelengths.

Results: Our results indicate, the decrease in catalase activity as a function of glycation time (weeks) for all samples, and a slight increase on its activity by different laser wavelengths irradiation for any fixed period of glycation time. Finally, as the laser’s photon energy (hυ) increases, the catalase activity also increases. More specifically, the blue laser (λ= 450nm) has the most and the red laser (λ = 638nm), has the least effect, and the green laser (λ = 530nm) has the medium effect on catalase activity. Furthermore, pulsed laser had an additional effect by increasing energy dosage. As we expected in all experiments, the increase in the catalase activity was coincident with the decrease in catalase fluoroscopy and CD parameters.

Use of Surgical Laser for Excision of a Neurofibroma Associated With Neurofibromatosis Type-1

Fabrício Rezende Amaral, Marcus Vinícius Lucas Ferreira, Lucas Araújo Pereira Costa, Patricia Alves Drummond de Oliveira, Betânia Maria Soares, Paulo Eduardo Alencar Souza, Gerdal Roberto de Sousa

Journal of Lasers in Medical Sciences, Vol. 9 No. 3 (2018), , Page 219-222

Introduction: Neurofibromatosis type 1 (NF1) is an autosomal dominant genetic disorder that affects approximately 1/3500 individuals. Various bone manifestations and peripheral nerves neoplastic lesions associated with NF1 are seen in the jaws. Several oral manifestations may occur in this disorder; therefore the dentist’s knowledge and multidisciplinary management of these patients are extremely important.
Case Presentation: In the present article, we present the use of a high-power surgical laser to excise a neurofibroma in a patient with several intraoral manifestations associated with NF1.
Conclusion: The use of diode laser (808 nm) for excision biopsy of tongue nodules showed no thermal damage to the tissue, allowing an adequate histopathological analysis of the neurofibroma