Comparative analysis of Laser and LED phototherapies pain control after insertion of elastomeric separators in orthodontics patients: Clinical trial.

The aim of this study was to evaluate the effectiveness of pain modulation following Laser or LED phototherapies during the process of tooth separation. This was a longitudinal randomized controlled clinical trial in four observational times carried out in 60 patients (15 males, 45 females, average 24.1 years old) who were randomly divided into three groups: G1 (LED, AsGaAl, λ850 ± 10 nm, 150 mW, 17 J/cm2, 57 s per session), G2 (Laser, AsGaAl, λ780 nm, 70 mW, 20.0 J/cm2, 240 s per session) and G3 (Non-irradiated Control). All patients were submitted to tooth separation using elastomeric separators. The pain level was measured by using a visual analogue scale (VAS) immediately after insertion (T1) of the elastic, at 48 (T2), 96 (T3) hours and 6 days (T4). It was observed an increase of the pain on the Control group from T1 to T2, with statistical significance. Pain levels in the LED and Laser groups were always significantly lower (<0.001), except for T1. According with the results of the present study it may be concluded that, either LED or Laser phototherapies, were effective in reducing the pain level after dental separation process when compared to the control group.

Clinical study on the efficacy of LED phototherapy for pain control in an orthodontic procedure.

Pain is an unpleasant and emotional subjective sensory experience that occurs during orthodontic procedures. Currently, LED phototherapy is an alternative to the use of laser light as analgesic agent due to similarity of response and lower cost. This case-control, quantitative, qualitative, and longitudinal study aimed to investigate the effect of IR LED phototherapy (λ846 ± 20 nm) in pain during the process of tooth separation during orthodontic treatment. After approval by the Institution Ethics Committee, 40 patients (30 female/10 male, 20-30 years old, average age 24.5 ± 2.6 years old) fulfilling the inclusion criteria entered the study and received a set of four visual analog scales (VAS) for scoring pain immediately, 48 h, 72 h, and 7 days after the insertion of the separating elastics. The patients were randomly distributed into two groups (experimental and control). The patients of experimental group received LED phototherapy (180 mW, 22 s, 4 J, 8 J/cm2, 0.36 W/cm2, spot of 0.5 cm2, spot diameter 0.8 cm) at the same times in which VAS was performed, and control patients were not irradiated. It was found that, in both groups, there was an increase in pain 48 h after insertion of the elastic tooth separator, decreasing 72 h after its installation and reached the lowest level of pain after 7 days. Comparison between groups showed that pain level in the LED group was always statistically significantly lower (p < 0.05), except for the time of installation (T1). The use of LED light was effective in significantly reducing the level of pain after insertion of the elastic tooth separators when compared to the control group.

Effect of low-level laser therapy irradiation and Bio-Oss graft material on the osteogenesis process in rabbit calvarium defects: a double blind experimental study.

This study aims to assess the effect of low-level laser therapy (LLLT) irradiation and Bio-Oss graft material on the osteogenesis process in the rabbit calvarium defects. Twelve white male New Zealand rabbits were included in this study. Four 8-mm diameter identical defects were prepared on each rabbit's calvarium. One site was left as an untreated control (C), the second site was filled with Bio-Oss (B), the third site was treated with laser irradiation (L), and the fourth site treated with Bio-Oss and laser irradiation (B + L). In the laser group, a diode laser (wavelength 810 nm, output power 300 mW, irradiation mode CW, energy density 4 J/cm2) was applied immediately after surgery and then one other day for the next 20 days. After 4 and 8 weeks, the animals were sacrificed and histological and histomorphometric examinations were performed and the data were subjected to Friedman and repeated measurements ANOVA tests. Significant differences were not found regarding inflammation severity, foreign body reactions, and vitality of newly formed bone on 4th and 8th week after operation. The mean amount of new bone was 15.83 and 18.5% in the controls on the 4th and 8th week; 27.66 and 25.16% in the laser-irradiated group; 35.0 and 41.83% in Bio-Oss and 41.83 and 47.0% in the laser + Bio-Oss treated specimens with significant statistical differences (p <0.05). Application of LLLT in combination with Bio-Oss® can promote bone healing. Therefore, LLLT may be clinically beneficial in promoting bone formation in skeletal defects.

Improvement of dermal burn healing by combining sodium alginate/chitosan-based films and low level laser therapy.

This paper aimed to evaluate the improvement of burn wounds healing by sodium alginate/chitosan-based films and laser therapy. Natural polymers with different biological activities are widely used as film dressings to improve wound healing. Lasers arrays accelerate the healing repair of soft tissue injuries. Burn procedures were performed on the backs of 60 male rats assigned into six groups: untreated (CTR), dressed with cellulose films (CL), dressed with sodium alginate/chitosan-based films (SC), laser-irradiated undressed wounds (LT), laser-irradiated wounds with cellulose (CLLT) and sodium alginate/chitosan-based films (SCLT). Laser therapy was applied for 7 days. Animals of each group were euthanised 8 and 14 days after the burn procedures. The inflammatory reaction was significantly more intense in the CTR group than in the irradiated groups after 8 and 14 days. Laser therapy stimulated myofibroblastic differentiation in 8 days, with or without dressing films. Combined laser therapy and both dressings improved epithelisation, blood vessels formation and collagenization, promoted rapid replacement of type III for type I collagen and favored the better arrangement of the newly formed collagen fibres. The combination of laser therapy and sodium alginate/chitosan-based dressing improves burn healing, apparently by modulating the epithelisation, blood vessels formation and collagenization processes.

The effect of the association of NIR laser therapy BMPs, and guided bone regeneration on tibial fractures treated with wire osteosynthesis: Raman spectroscopy study.

Bone fractures are lesions of different etiology; may be associated or not to bone losses; and have different options for treatment, such as the use of biomaterials, guided bone regeneration, techniques considered effective on improving bone repair. Laser therapy has also been shown to improve bone healing on several models. The association of these three techniques has been well documented by our group using different models. This study aimed to assess, through Raman spectroscopy, the incorporation of calcium hydroxyapatite (CHA approximately 958 cm(-1)) on the repair of complete tibial fractures in rabbits treated with wire osteosynthesis (WO); treated or not with laser therapy; and associated or not with the use of BMPs and/or Guided Bone Regeneration. Complete tibial fractures were created in 12 animals that were divided into four groups: WO; WO+BMPs; WO+laser therapy; and WO+BMPs+laser therapy. Irradiation started immediately after surgery; was repeated at every other day during 2 weeks; and was carried out with lambda 790 nm laser light (4 J/cm(2) per point, 40 mW, phi approximately 0.5 cm(2), 16J per session). Animal death occurred after 30 days. Raman spectroscopy was performed at both the surface and the depth of the fracture site. Statistical analysis showed significant difference on the concentrations of CHA between surface and depth. The analysis in each of the areas showed at the depth of the fracture significant differences between all treatment groups (p<0.0001). Significant differences were also seen between WO+BMPs+laser therapy and WO (p<0.001) and WO+laser therapy (p<0.001). At the surface, significant difference was seen only between the treatment groups and the non-fractured subjects (p=0.0001). However, no significant difference was seen between the treatment groups (p=0.14). It is concluded that the use of NIR laser therapy associated to BMPs and GBR was effective in improving bone healing on the fractured bones as a result of the increasing deposition of CHA measured by Raman spectroscopy.

Electro-oxidation of carbon monoxide and methanol on bare and Pt-modified Ru(1010) electrodes.

The activity towards CO and methanol electrooxidation of bare and platinum-modified Ru(1010) surfaces has been investigated. The structure/morphology and composition of the modified surfaces were characterized using electron diffraction techniques (LEED, RHEED) and Auger spectroscopy. The bare Ru(1010) surface exhibits a higher catalytic activity towards CO electrooxidation than the Ru(0001) surface due to the lower oxidation potential of the former surface. The early stages of surface oxidation lead to disordering of the surface and further enhancing of the electrocatalytic activity. Electrodeposition of Pt on Ru(1010) leads to epitaxial growth via a Volmer-Weber growth mode. The Pt clusters grow preferentially with the (311) plane parallel to the substrate surface with (011) rows in the layers in contact with the substrate compressed by about 3% with respect to bulk Pt, in order to match with the (1210) rows of the Ru(1010) surface. This compression leads to enhanced catalytic activity towards CO oxidation for thin Pt deposits whereas for large deposited Pt particles the dominating factor for the catalytic enhancement is the higher concentration of surface defects. On the other hand, in the case of methanol oxidation, the dominant factor in determining the catalytic activity is the concentration of adjacent Pt-Ru sites, although surface defects play an important role in the methanol dehydrogenation steps.

Assessment of anti-inflammatory effect of 830nm laser light using C-reactive protein levels.

The anti-inflammatory effect of non-surgical lasers has been proposed previously, however it was not scientifically proven. One method to assess levels of inflammation is the measurement of C-reactive protein (CRP), which is increased with the course of inflammation. The aim of this study was to assess the effect of 830 nm laser irradiation after the removal of impacted third molars using the CRP as the marker of inflammation. Twelve patients were irradiated with 4.8 J of laser light per session 24 and 48 h after surgery. A control group (N = 12) was treated with a sham laser. Blood samples were taken prior to, and 48 and 72 h after surgery. CRP values were more symmetric and better distributed for the irradiated group (0.320 mg/dl) than for the control (0.862.mg/dl) 48 h after surgery, however there was no statistically significant difference. After 72 h, both groups had statistically similar CRP levels (0.272 and 0.608 mg/dl), because of the normal tendency of decreasing CRP levels.

Biostimulatory windows in low-intensity laser activation: lasers, scanners, and NASA's light-emitting diode array system.

OBJECTIVE: The purpose of this study was to assess and to formulate physically an irreducible set of irradiation parameters that could be relevant in the achieving reproducible light-induced effects in biological systems, both in vitro and in vivo. BACKGROUND DATA: Light-tissue interaction studies focusing on the evaluation of irradiation thresholds are basic for the extensively growing applications for medical lasers and related light-emitting systems. These thresholds are of central interest in the rejuvenation of collagens, photorefractive keratectomy, and wound healing. METHODS: There is ample evidence that the action of light in biological systems depends at least on two threshold parameters: the energy density and the intensity. Depending on the particular light delivery system coupled to an irradiation source, the mean energy density and the local intensity have to be determined separately using adequate experimental methods. RESULTS: From the observations of different research groups and our own observations, we conclude that the threshold parameters energy density and intensity are biologically independent from each other. CONCLUSIONS: This independence is of practical importance, at least for the medical application of photobiological effects achieved at low-energy density levels, accounting for the success and the failure in most of the cold laser uses since Mester's pioneering work.

Quantitative evaluation of intact peripheral nerve structures after utilization of CO2 laser, electrocautery, and scalpel.

OBJECTIVE: This study aimed to evaluate quantitatively the integrity of nerve structures near CO2 laser incisions. BACKGROUND DATA: There are some hypotheses that try to explain the analgesia reported after CO2 laser surgery. One of them is based upon the observation of the destruction of nerve endings after use of this technique. METHODS: A comparative study was carried out using 25 animals (Rattus norvegicus) divided into five groups of 5 animals each. Standard incisions were carried on the dorsum of the tongue of each animal using the cautery (group 2), scalpel (group 3), CW CO2 laser (group 4), and SPS CO2 (group 5); group I served as control. The animals were killed immediately after the experiment, and specimens were taken and routinely processed to wax. Three-micrometer sections were cut and stained using S-100 protein antibody. The stained sections were analyzed under light microscopy using a calibrated graticule, and the number of intact nerves was counted in five standard areas around the incision. RESULTS: The results of this study showed that there were no statistically significant differences in the numbers of intact peripheral nerve structures in both laser groups and other groups. No statistically significant difference was found between nonoperated and scalpel groups. The number of intact peripheral structures in cautery wounds was significantly smaller than in non-operated and scalpel wounds. CONCLUSIONS: Therefore, it is unlikely that immediate destruction of peripheral nerve structures is the cause of post-operative analgesia following CO2 laser surgery.

A rare case of lip ulcer infected by Klebsiella pneumoniae: case report.

The aetiology of mouth ulcers is diverse and may include several types of trauma, systemic disease and infection. The size, depth, outline, base, aspect of the floor, pain, time of evolution and resolution of oral ulcers are discussed. Both past and present medical history, biopsy, blood tests and microbiological tests are also considered in order to assure precise identification. This paper reports a case of a lip ulcer caused by Klebsiella pneumoniae.

Manifestations of periodontal diseases in AIDS patients.

The aim of this study is to analyze periodontal diseases in AIDS patients. Although AIDS was first detected in Brazil in 1982, it is growing steadily and is more frequent in the Southeast. Oral manifestations are common and may represent early signs of the disease. These lesions often precede systemic symptoms. The development of periodontal lesions in AIDS patients differs from that in non-infected patients. This is due to its chronic nature and lack of full recovery in AIDS patients. Characteristically, these lesions are not related to local irritants and progress quickly. Because these lesions do not respond properly to conventional treatment used in non-infected patients, the use of preventive methods is extremely important. These methods must include patient education and periodical professional scaling. It is important to reinforce the use of preventive measures in AIDS patients mainly in those presenting severe manifestations of the disease. The aim of treatment must be to preserve the teeth and periodontal tissues and allow more comfort to the patient during the progression of the disease.

Low-level laser therapy is an important tool to treat disorders of the maxillofacial region.

OBJECTIVES: The authors report on the effects of low-level laser therapy (LLLT) in the treatment of maxillofacial disorders. SUMMARY AND BACKGROUND DATA: Further to our previous studies, this paper reports the results of the use of LLLT on the treatment of several disorders of the oral and maxillofacial region. This paper presents LLLT as an effective method of treating such disorders. METHODS: Two hundred and five female and 36 male patients ages between 7 and 81 years old (average 38.9 years old), suffering from disorders of the maxillofacial region, were treated with 632.8, 670, and 830 nm diode lasers at the Laser Center of the Universidade Federal de Pernambuco, Recife, Brazil (UFPE). The disorders included temporomandibular joint (TMJ) pain, trigeminal neuralgia, muscular pain, aphatae, inflammation, and tooth hypersensitivity postoperatively and in small hemangiomas. Most treatment consisted of a series of 12 applications (twice a week) and in 15 cases a second series was applied. Patients were treated with an average dose of 1.8 J/cm2. RESULTS: One hundred fifty four out of 241 patients were asymptomatic at the end of the treatment, 50 improved considerably, and 37 were symptomatic. CONCLUSIONS: These results confirm that LLLT is an effective tool and is beneficial for the treatment of many disorders of the maxillofacial region.

Using Novafil: would it make suturing easier?

The use of monofilament nonabsorbable suture materials is not common in Dentistry. Although it is known that multifilament suture materials induce greater cellular reaction, most Dentists prefer to use cotton and silk. Rigidity and package memory are disadvantages of monofilament nonabsorbable suture materials. A new material, Polybutester (Novafil), has been used successfully in Medicine but its use is not common in Dentistry. Seventy male and female Wistar rats were used to study the clinical response of skin and abdominal wall muscle to the use of Novafil and nylon sutures. Under general anesthesia, standard wounds were created in the dorsum and abdomen of the animals and sutured with either Novafil or nylon. The animals were sacrificed immediately, 12, 24, and 72 hours and at 4, 5 and 7 days to evaluate the clinical aspect of both wounds. Polybutester presented some advantages such as strength, lack of package memory, elasticity and flexibility which made suturing quicker and easier. Some subjects presented abdominal wound edema during the period and six animals developed infection of abdominal wounds within seven days. These initial findings show that Novafil is easy to handle and would be better tolerated in the mouth than nylon resulting in less discomfort for the patient. Novafil can be used safely on skin and mucosal wounds and, if necessary, it can be used in internal sutures because it irritates less than nylon.

Low-level laser therapy in the management of disorders of the maxillofacial region.

OBJECTIVE: The authors analysed the effects of low-level laser therapy (LLLT) on the treatment of maxillofacial disorders. SUMMARY BACKGROUND DATA: Pioneer work published by Mester et al. opened a new frontier in the clinical treatment of many disorders with the use of LLLT. Although LLLT is not well accepted in many places, its use is growing steadily in others, including Europe and more recently in Brazil. METHODS: One hundred forty-one female and 24 male patients, between 7 and 81 years of age (average = 39.2 years old), suffering from disorders of the maxillofacial region were treated with 632.8-nm, 670-nm, and 830-nm diode lasers at the Laser Center of the Universidade Federal de Pernambuco. The disorders included temperomandibular joint pain, trigeminal neuralgia, muscular pain, aphatae, inflammation, and tooth hypersensitivity both postoperatively and in small hemangiomas. Most treatment consisted of a series of 12 applications (twice a week), and in eight cases a second series was applied. Patients were treated with an average dose of 2.5 J/cm2. RESULTS: One hundred twenty out of 165 patients were asymptomatic at the end of the treatment, 25 improved considerably, and 20 were symptomatic. CONCLUSIONS: These preliminary results indicate that LLLT is an important tool and brings many benefits for the treatment of many disorders of the maxillofacial region.

Surgical management of premalignant lesions of the oral cavity with the CO2 laser.

The management of patients with premalignant and malignant lesions of the oral cavity can present problems. The potentially invasive nature of premalignant lesions together with their large extent influences the treatment. The common modalities of treatment of these lesions are surgical excision, cryotherapy, electrosurgery and radiotherapy. Recently, CO2 laser surgery has become available. Less pain, little bleeding, minimal post-operative edema, reduced risk of infection, and low recurrence rates were advantages observed following CO2 laser surgery in the mouth when compared to other modalities of treatment. Healing following CO2 laser surgery progressed well with little postoperative scarring and re-epithelialization was complete after 4-6 weeks. The newly formed epithelium appeared normal and was soft on palpation.

Mast cells in laser and surgical wounds.

Precooling of tissues was investigated as a possible means of reducing thermal damage during CO2 laser surgery of the oral mucosa. The changes in mast cells in scalpel, and in non-cooled and precooled (tissue temperature lowered to approximately 10 degrees C) CO2 laser wounds were studied. Standard wounds five mm in length were created with the CO2 laser or scalpel on the dorsum of the tongues of 32 Sprague-Dawley rats under general anesthesia with fentanyl/fluanisone and midazolam. Animals were killed with excess anesthetic immediately or six hours after surgery, their tongues were removed, trimmed, fixed in neutral formalin and processed to paraffin wax. Acid (pH 1.4) toluidine blue stained sections were used to count normal and degranulated mast cells in five fields (0.1 mm2) located at defined positions immediately adjacent to the wound site. At both 0 and 6 hours normal mast cell numbers were significantly different between treatment groups (P<0.045; ANOVA) with mean numbers highest in scalpel wounds and lowest in uncooled laser wounds. Similarly, at 0 time, there were significant differences in degranulated mast cells between treatment groups (P=0.004; ANOVA) but highest numbers were detected in uncooled laser wounds and lowest in scalpel wounds. There were no significant differences in degranulated mast cell counts at six hours although there was a similar distribution in numbers between groups. Total numbers of mast cells (normal + degranulated) did not differ between treatment groups. These results demonstrated that i) laser wounds are associated with greater levels of mast cell degranulation than scalpel wounds and ii) precooling of tissues prior to laser treatment decreases the level of mast cell degranulation. It is concluded that tissue damage in CO2 laser surgery may be reduced by precooling of tissue.

Assessment of thermal damage in precooled CO2 laser wounds using biological markers.

Precooling of the tissues was investigated as a possible means of reducing the thermal damage during CO2 laser surgery of the oral mucosa. Standard wounds 5 mm long were created with the CO2 laser, with and without precooling, or the scalpel on the dorsum of tongues. Tissue damage was evaluated by studying changes in mast cells and in the activity of lactate (LDH) and succinate (SDH) dehydrogenase. Cooled unoperated tongues acted as controls. The area of thermal damage, indicated by loss of SDH activity, was significantly smaller in precooled tissues (p < 0.001). Although a similar pattern was detected using LDH, the difference was not significant. At both 0 and 6 h normal mast cell numbers were significantly different between groups (p < 0.02). Furthermore, at 0 time, there were significant differences in the numbers of degranulated mast cells between surgical treatment groups (p = 0.001), although not at 6 h. Total numbers of mast cells (normal and degranulated) did not differ between treatment groups or between 0 and 6 h sampling times. Positive significant correlations were observed between the cross-sectional areas and widths of non-reactive succinate and lactate dehydrogenase and the number of degranulated mast cells around the laser wounds. Analysis of the data demonstrated that (i) uncooled laser wounds but not precooled laser wounds were associated significantly with greater levels of immediate mast cell degranulation than scalpel wounds (p = 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)