Journal of Lasers in Medical Sciences

One of the basic purposes in dental treatment is providing a painless treatment for patients. This purpose may be achieved by the application of laser in dentistry. Low-level laser therapy (LLLT) is an internationally accepted title for biomodulation with low-level lasers which we use to achieve ideal therapeutic effects. Low-level laser therapy is a painless, reproducible, non-invasive, and without need of anesthesia treatment which is used to treat a variety of pain syndromes, injuries, wounds, fractures, neurological conditions and pathologies. Laser therapy works on the principle of inducing a biological response through energy transfer. The parameters that used in laser therapy determine the effective depth of penetration. We can mention anti-inflammatory effects, stimulation of wound healing, stimulation of immune system, increase of blood flow and activation of vasodilatation, increase of cellular metabolism and analgesic effects as advantages of the application of this type of laser. The aim of this review study was to evaluate the effect of low-level laser therapy after oral surgeries.

INTRODUCTION: Due to penetration of pathogenic bacteria into the periodontal tissues in moderate to severe periodontitis, the mechanical methods are not sufficient in these cases. Therefore, administration of local/systemic antibiotic is recommended following mechanical root debridement. However, side effects of antibiotics such as microbial resistance and patient allergy led to development of alternative methods. One of the suggested methods is the antimicrobial photodynamic therapy (aPDT). aPDT is a local non invasive treatment modality without the side effects caused by antibiotics. The aim of this study was to collect the clinical articles related to the application of aPDT in the treatment of chronic periodontitis.

METHODS: In order to find related clinical articles, a search of PubMed, Google Scholar and Science Direct until 2012 was performed.

RESULTS: A total of 11 articles were found. In 7 of the 11 articles, the assessment of aPDT led to a significant improvement in the clinical attachment and probing depth. In 4 studies, there was no difference between the scaling & root planing (SRP) and adjunctive application of aPDT. aPDT in most cases resulted in less gingival bleeding compare to SRP alone. Furthermore, its application in multiple doses was more effective in comparison to a single dose treatment.

CONCLUSION: It appears that aPDT is effective as an adjunctive therapy compared to conventional non_surgical treatment alone, and is recommended in multiple doses in order to achieve more appropriate results.

INTRODUCTION: The purpose of the present study was to determine the effect of 17% Ethylene,di-amine, tetra-acetic acid (EDTA), 6% phosphoric acid and Erbium: Yttrium, Aluminum, Garnet (Er:YAG) Laser in removing the smear layer by scanning electron microscopy.

METHODS: In this study, 80 single-rooted human teeth were selected. Instrumentation was done by use of hand files and step-back technique up to file #40 at apical and file #80 at coronal area. During instrumentation, 1ml of 5.25% sodium hypochlorite (NaOCl) was used as irrigation between each file. The teeth were randomly divided into four groups with different methods of smear removal.17% Ethylene, di-amine, tetra-acetic acid was used in group 1, 6% Phosphoric acid in group 2, Erbium: Yttrium, Aluminum, Garnet laser in group 3, and no intervention in group 4 (as control). Roots were then longitudinally sectioned and prepared for scanning electron micrograph in cervical, middle and apical areas. Data were analyzed by Kruskal-Walis, Mann-Whitney, Friedman and Wilcoxson tests (P<0.05).

RESULTS: The results showed a significant difference in smear layer removal between three methods in favor of the EDTA (P<0.001) and Phosphoric groups (P<0.001) with no significant difference between them (P=0.49). Although Er:YAG laser showed some limited ability to remove the smear layer, the effectiveness was not significantly different from the control group (P=0.157).

CONCLUSION: Based on the findings of this study, EDTA and Phosphoric acid were effective methods to remove smear layer from the root canal walls but Er:YAG laser showed less efficacy compared to the other experimental groups.

INTRODUCTION: Various methods have been used for the treatment of dentine hypersensitivity such as dentifrices, sealants and different types of lasers. The aim of this study was to evaluate the effect of Neodimium:Yttrium-Aluminium-Garnet (Nd:YAG) laser in association with graphite on the dentin morphologic changes.

METHODS: In this experimental in vitro study, 16 freshly extracted third molars were selected. 5 specimens with the dimensions of 2×2×1 mm from root trunk were prepared. Specimens were randomly divided into five groups: group 1 (control, no laser irradiation). Group 2, 3 irradiated by Nd:YAG laser 0.5 and 1W, output power respectively. Group 4, 5 smeared with graphite and then irradiated by Nd: YAG laser 0.5 and 1W output power. Samples were prepared for scanning electron microscopy. Number and diameter of dentinal tubules were determined in different groups and analyzed with the Kruskal-wallis and Mann-Whitney tests (SPSS 16).

RESULTS: The number of tubules had significant difference between all groups (P<0.001), except group 1 in comparison with group 2 (P> 0.05), and group 3 in comparison with group 4 (P> 0.05). Micro-cracks and rupture of melted dentin materials were seen in group 4 and 5.

CONCLUSION: According to the findings of this study, smearing with graphite on dentin surface increase the absorption of Nd:YAG laser energy and reduced the diameter and number of open dentinal tubules.

INTRODUCTION: Port wine stains (PWS) are congenital vascular malformations. Pulsed dye laser (PDL) is the treatment of choice till now, although many lesions do not respond completely. One of possible options is long pulsed alexandrite laser. Some literatures confirmed its efficacy. The aim of the present study is to determine the efficacy of this laser as an option in treating refractory PWS in Iranian patients.

METHODS: Patients with refractory PWS lesions that did not respond to at least six PDL sessions were included if they had no history of Isotretinoin consumption in past year, history of keloid or hypertrophic scar formation, active infection in laser site and if they were not pregnant. All patients signed an informed consent. Alexandrite laser with fluencies from 36-40J/Cm2, 12 mm spot size, 3 ms pulse duration and dynamic cooling device tuned to 50/50 ms was used in three successive sessions to treat lesions. All patients photographed before each session and after 8 weeks from the last sessions. Then, pictures were rated by two blinded dermatologist rater to determine degree of response based of visual analog scaling from score 1(below 25% response) to score 4 (more than 75% response).

RESULTS: A total of 20 patients comprised of 12 males and 8 females with mean age of 23 years were included. 35% (7 patients) had score of 1, 35% (7 patients) had score of 2, 25% (5 patients) had score of 3 while one patient (5%) reached score 4. No serious side effect was observed. There was no significant relationship with age, gender and size of lesions and response rate.

CONCLUSION: It seems that considering a conservative approach, long pulsed alexandrite laser may be an effective option in treating refractory PWS lesions. Although future studies with higher sample size using higher fluences are required to confirm these results.

INTRODUCTION: The unprotected eye is extremely sensitive to laser radiation and can be permanently damaged from direct or reflected beams. The area of the eye damaged by laser energy is dependent upon the wavelength of the incident laser beam, duration of exposure and tissue characteristics. This study aims to investigate the effect of intense green light from doubled frequency Neodymium-Doped Yttrium Aluminum Garnet (Nd:YAG) (532nm) in the nanosecond range on the protein of rabbits lenses after short and prolonged (6, 18 seconds) exposures.

METHODS: The fundamental wavelength (1064 nm) was frequency doubled in β- Barium Borate (BBO) crystal for second harmonic generation (SHG). Rabbits’ lenses were irradiated in vitro, and the effect of the laser was evaluated by comparing the protein concentration, structure and conformation by sodium dodecyle sulphate polyacrylamide electrophoresis (SDS-PAGE) and Fourier transform infrared spectroscopy (FTIR).

RESULTS: The results indicated a significant change in the soluble protein content, the molecular weights and the backbone structure of different lens crystallin fractions. These effects were more distinct when using laser with prolonged irradiation for 18 seconds than for 6 seconds.

INTRODUCTION: The aims of the present study were: [1] to evaluate whether Erbium-Doped: Yttrium, Aluminum and Garnet (Er: YAG) laser could be a prophylactic methods against transient bacteremia during scaling and root planing (SRP) [2] to confirm the efficacies of SRP with Er: YAG laser by clinical and microbiologic evaluations.

METHODS: Twenty chronic periodontitis subjects were randomly treated for quadrant SRP with either conventional hand instrument (n=10) or Er: YAG laser (n=10) monotherapy. Peripheral blood samples were drawn at baseline and 6 minutes after initiation of SRP, and were cultured for the analysis of bacteremia. Clinical measurements of full mouth plaque control record (PCR), probing pocket depth (PPD), clinical attachment level (CAL) and bleeding on probing (BOP) were made at baseline and 1 month after SRP. In addition, microbiologic analyses of subgingival samples were also performed at baseline and 1 month after SRP using the polymerase chain reaction Invader method.

RESULTS: The incidence of bacteremia during SRP was 0% (0/10) in the Er: YAG laser group and 80% (8/10) in the hand instrument group, which was significantly different (P = 0.0003). All isolates from blood were facultative or obligate anaerobes and more than half of the microorganisms were species of streptococci. Intragroup comparison revealed that the mean PPD and CAL significantly decreased compared to baseline in both groups (P < 0.05). However, the percentage of BOP positive significantly decreased only in Er: YAG laser group (P = 0.005). In addition, the reductions of the subgingival bacterial counts between baseline and 1 month after SRP were also comparable between the two groups.

CONCLUSION: The present study demonstrated that SRP with Er: YAG laser could not only be an alternative treatment for improvement of clinical and microorganisms situations but also a novel prophylactic method against transient bacteremia.

The purpose of these case reports is to analyze the results of gingivectomy and gingival troughing to determine the evidence on the effectiveness of laser-assisted soft tissue procedures and soft tissue management in aesthetic dentistry.The patients in these case reports underwent 980 nm diode laser assisted gingivectomy and gingival troughing to achieve immediate hemostasis and moisture control, adjunctive to the aesthetic restoration of the carious lesion and prosthetic rehabilitation of the posterior tooth.Successful healing of gingival tissues has been observed after 15 days in both cases. Also, laser assisted gingival tissue management allowed the operator to finish and polish the restoration on the same day.The ability of soft tissue lasers to control moisture and facilitate hemostasis appears particularly promising for clinicians excising gingival tissue, and using resective techniques for gingival troughing. Treatment with a dental laser ensures a successful aesthetic procedure with proper tissue form, function and biocompatibility.