Physiological aging leads to dysfunction of the stomatognatic system. Photo-kinesiotherapy (PKT) is a program using photobiomodulation (PBM) in combination with different kinesiotherapies. PBM can slow down and manage aging process resulting in orofacial dermal-neuro-muscle rehabilitating. We are searching for a new more efficient therapy to decrease and manage velocity of senescence and dysfunction of stomatognatic system. Under Ethical Comittee approval (CAAE no. 45390715.2.0000.5419), fifteen female patients were selected and divided into 5 groups: G1 - Control group (cosmetics); G2 - Light group (cosmetics + PBM); G3 - Exercises Group (Cosmetics+ PBM + orofacial exercises); G4 - Electrotherapy Group (Cosmetics+ PBM + Electrotherapy - Aussie current); and, G5 - Taping Group (Cosmetics+ PBM + kinesiotherapy). Muscle evaluation was performed using electromyography, ultrasonography and bite force. Skin evaluation was performed in terms of skin hydration and viscoelasticity, skin echogenicity using ultrasonography and standardized high resolution photographies. Measures were done before (baseline values) and after 7 days and 30 days of treatment. The pilot phase (fifhteen patients) was concluded using Kruskal-Wallis statistical tests that showed non-significant differences between groups. However, all treatments affected muscle tone, cutaneous elasticity and dermis echogenicity resulting in interesting individual clinical observations.We suggest that the combination of cosmetics, mechanical and optical stimulus to all kind of different tissues from stomatognathic system can be an efficient choice to orofacial functional and aesthetic rehabilitation. (CNPq - 114735/2015-8)
Skin hydration is important to prevent aging and dysfunction of orofacial system. Nowadays, it is known that cutaneous system is linked to muscle system, then every dentist need to treat healthy facial skin, as lips, keeping orofacial functions healthy. Thirty-two patients were treated using laser and led therapy single or associated to biomaterials (dermo-cosmetics) searching for the best protocol to promote skin hydration. Using a peace of equipment to measure electric impedance, percentage of water and oil from skin, before and after different treatments were analyzed. Statistic tests using 5% and 0.1% of significance were applied and results showed that light could improve hydration of epidermis layer of facial skin. Considering just light effect, using infrared laser followed by blue led system is more effective to hydration than just blue led system application. Considering dermo-cosmetic and light, the association between both presented the best result.
Considering several clinical situations, low intensity laser therapy has been widely applied in pain relief or analgesia mechanism. With the advent of new LED-based (light emitting diode) light sources, the need of further clinical experiments aiming to compare the effectiveness among them is paramount. The LED system therapeutic use can be denominated as LEDT - Light Emitting Diode Therapy. This study proposed two clinical evaluations of pain relief effect: to dentin hypersensitivity and to cervicogenic headache using different sources of lasers (low and high intensity) and light emitting diodes (LEDs), one emitting at the spectral band of red (630+/- 5nm) and the other one at infrared band (880+/- 5nm). Two different clinical studies were performed and presented interesting results. Considering dentin hypersensitivity, red and infrared led were so effective than the control group (high intensity laser system); by the other side, considering cervicogenic headache, control group (infrared laser) was the best treatment in comparison to red and infrared led system.
Blue LED system irradiation shows many important properties on skin as: bacterial decontamination, degradation of endogenous skin chromophores and biostimulation. In this clinical study we prove that the blue light improves the skin hydration. In the literature none authors reports this biological property on skin. Then this study aims to discuss the role of blue light in the skin hydration. Twenty patients were selected to this study with age between 25-35 years old and phototype I, II and III. A defined area from forearm was pre determined (A = 4.0 cm2). The study was randomized in two treatment groups using one blue light device (power of 5.3mW and irradiance of 10.8mW/cm2). The first treatment group was irradiated with 3J/cm2 (277seconds) and the second with 6J/cm2 (555 seconds). The skin hydration evaluations were done using a corneometer. The measurements were collected in 7, 14, 21 and 30 days, during the treatment. Statistical test of ANOVA, Tukey and T-Student were applied considering 5% of significance. In conclusion, both doses were able to improve the skin hydration; however, 6J/cm2 has kept this hydration for 30 days.
Femtosecond lasers have been widely used in laser surgery as an instrument for contact-free tissue removal of hard dental, restorative materials, and osseous tissues, complementing conventional drilling or cutting tools. In order to obtain a laser system that provides an ablation efficiency comparable to mechanical instruments, the laser pulse rate must be maximal without causing thermal damage. The aim of this study was to compare the different morphological characteristics of the hard tissue after exposure to lasers operating in the femtosecond pulse regime. Two different kinds of samples were irradiated: dentin from human extracted teeth and bovine femur samples. Different procedures were applied, while paying special care to preserving the structures. The incubation factor S was calculated to be 0.788±0.004 for the bovine femur bone. These results indicate that the incubation effect is still substantial during the femtosecond laser ablation of hard tissues. The plasma-induced ablation has reduced side effects, i.e., we observe less thermal and mechanical damage when using a superficial femtosecond laser irradiation close to the threshold conditions. In the femtosecond regime, the morphology characteristics of the cavity were strongly influenced by the change of the effective number of pulses.
In this work the color dependence of resin composites with the background color was evaluated. The objective was to
measure since what thickness the color of the sample stops being influenced by the color of the background over which
the resin is placed and the methodology used in experiment was based in analyzing the contrast of digital images of the
sample over a black background. The results shown that since 0.8 mm the images contrast becomes almost constant; it
prove that since this thickness the color of resin composite depends on the optical resin properties only. The experiment
was repeated under three conditions of luminosity to evaluate the influence of it on the image contrast and the results
obtained were identical.
A major characteristic of LEDs systems is the lower heat emission related with the kind of light
generation and spectral emission band. Material temperature during photoactivation can promote
different photocuring performance. Organic dye penetration could be a trace to identify the efficacy of
photocured composite resin. A new method using fluorescent spectroscopy through digital image
evaluation was developed in this study. In order to understand if there is a real influence of material
temperature during the photoactivation procedure of a dental restorative material, a hybrid composite
resin (Z250, 3M-Espe, USA) and 3 light sources, halogen lamp (510 mW/cm2) and two LED systems 470±10nm (345 and 1000 mW/cm2) under different temperatures and intensities were used. One thousand and five hundred samples under different associations between light sources and temperatures (0, 25, 50, 75 and 100oC were tested and immediately kept in 6G rodamin dye solution. Dye penetration was evaluated through fluorescent spectroscopy recorded by digital image data. Pixels in gray scale showed the percentage penetration of organic dye into the composite resin mass. Time and temperature were statistically significant (p<0.05) through the ANOVA statistical test. The lowest penetration value was with 60 seconds and 25oC. Time and temperature are important factors to promote a homogeneous structure polymerized composite resin more than the light source type, halogen or LEDs system.
The dental bleaching is known for many years. Recently a technique employing light has
open up new and exciting possibilities. Besides its vast application there are still many
important points to be understood about teeth photon bleaching. In this work we present an
"in vitro" experiment to explore the main mechanisms involved during the photon action in
tooth whitening. Our results indicated that light at same wavelengths are great absorbed by
pigments creating a local heating which considerably increase the bleaching rate. This
results in a fast reaction without heating the whole dental structure. We discuss details of
our experiment. Work supported by Fapesp and CNPq.
This work presents a study to understand the interaction between Er:YAG laser and composite resin. The main purpose is the development of a new ultra-conservative clinical technique: differential ablation for composite resin restorations using Er:YAG laser. A hybrid composite resin (Z100, 3M, USA) formatted as tablets recently cured was used and after artificial aging method the teeth were irradiated with a Er:YAG laser and two different conditions were considered, energy level per pulse (100, 300 and 500mJ), frequencies (5, 10 and 15Hz) and different water fluxes. Diameter and depth of each resulted microcavity was measured and the material removed volumes were calculated. The resulted values were plotted and feted to allow a comparative observation of the material removed as a function of energy level per pulse. Frequencies of 5 and 10Hz were similar between them and seemed to allow the highest material ablated volume, however considering the energy per pulse parameter, 300mJ was more efficient than the others, mainly when water flux was around 0.1ml/s. The highest water flux showed lower ablation rate with the lowest fluency. Water fluxes presented an important factor considering composite ablation, even because it could modulate depth and surface regularity of the irradiated material.
KEYWORDS: Light sources, Light emitting diodes, Chemical reactions, Dental bleaching, Blue light emitting diodes, Absorption, RGB color model, 3D modeling, Hydrogen, Chemical elements
The bleaching process is been objective of many studies since the beginning of the XX century. Heat has been used to activate the hydrogen peroxide; the aesthetic results were satisfactory, but associated with this process high incidence of hypersensitivity as well as radical endodontic treatment was observed making this technique clinically hard to implemented.
Nowadays the dental bleaching is one of the most wanted aesthetic procedures by the population at the dental office. With the utilization of new light sources as LASER and LED a technique to evaluate the efficiency of photo-bleaching of many pigments is necessary.
This work demonstrates a new method to quantify the breakage of pigments on a cellulose matrix using a blue LED system with 1W/cm2. We employed a computational analysis and digital spectroscopy. These matrixes were used because of its inert physical-chemical properties.
The obtained results are within the expectative, where the groups irradiated with light presents more broken pigments that the group with no light, it was also possible to observe on this experiment that light acts decreasing the free energy of the reaction and that way speeding up the rate of bleaching.
Dentin hypersensitivity is the most common patient's complain related to pain. In fact, this is a challenge to treat specially if conventional techniques are used. The possibility to treat pain through a low intensity laser gives us an opportunity to solve this important clinical problem without promote a discomfort to patient. The main point here is not if this kind of treatment is anti- inflammatory to pulp and/or biostimulatory to production of irregular secondary dentin. The most important point here is to understand how much energy is necessary to reach conditions where to tooth become insensible to external stimulus. Our double-blinded study compared a group without laser (Placebo) with five other groups where different doses at 660 nm low intensity laser were employed. The final conclusion is that for 660 nm laser therapy, the doses from 0.13 to 2.0 J/cm2 were more efficiency than the others. The follow up care in this study was of 45 days.
Occlusal surface caries are very difficult to diagnose at early stages, special difficulties are observed when the lesion is formed bilaterally in the pits and fissures walls. Preventive measures have been a constant concerning in the attempt to reduce the installation and progression of incipient occlusal decays. The early carious lesions detection through conventional diagnosis methods are questionable because they can end up with a risk of a false-positive or false-negative diagnosis. Using 22 teeth in vitro, premolars and molars, which suggested carious lesions, the exams were made by 3 examiners calibrated through pre-determined scores. The utilized methods were: GI -- visual inspection, GII -- tactile inspection (explorer probe), GIII -- conventional radiographic exam, GIV -- digital radiographic exam (Digora for Windows 1.51 and 1.51N, Soredex-orion Co.), GV -- low intensity laser for diagnosis (DIAGNOdent, KaVo, Germany) and GVI -- histologic section. The examiners did not communicate among themselves during the exams. There were significant statistical difference among the evaluated methods. Under Friedman statistical test, GI, GIII and GIV were different from GV at the 0.1% level; when we have compared GII with GV, we observed statistical difference at the 1% level. In conclusion, GV was highly statistically different from the others groups, it means that the low intensity laser for diagnosis was the most sensible method to detect decayed tissue.
The evaluation of microleakage is a method conventionally used to evaluate the composite restoration in cavities prepared by laser or conventional drill. The samples were five sound molar human extracted teeth with cavity preparation Class V in each surface (buccal, lingual, mesial and distal) divided in: GI -- cavity preparation with Er:YAG laser, adhesive agent Single Bond (3M), composite Z100 (3M) color A2; GII -- cavity preparation laser, 35% phosphoric acid etching, adhesive, composite; GIII -- cavity preparation with a drill, adhesive, composite; GIV -- cavity preparation with a drill, acid etching, adhesive, composite. The samples were sealed with a coating of nail varnish except on the area of the restoration and immersed in 50% aqueous solution of silver nitrate for 24 hours while kept in darkness. Samples were rinsed, soaked in photorevealing solution and exposed to fluorescent light for 6 hours. After, they were embedded in epoxy resin and sectioned longitudinally using the diamond saw microtone under running water. The specimens were observed under optical microscopy and the results were analyzed under Kruskall Wallis resulting in difference statistically between GI X GIV at the 5% level; and under Mann-Whitney resulting non-difference statistically between groups divided in cervical or occlusal walls.
One of the most important difficulty in the periodontal disease treatment resides in the impossibility of decontamination of roots just affected by the periodontal disease through mechanical tools. Manual dental scaling results in the amorphous material without continuity solution due to the dental cut, denominated smear layer. The main purpose of the present study was to evaluate the structure of the radicular surface using two methods for periodontal treatments: manual and mechanical associated to the irrigation with water and with EDTA (ethylene diamine tetracycline acid), followed by the application of the Er:YAG laser or the same without laser. Thirty teeth were selected with periodontal involvement. The radicular surface was scraped with ultrasound and planed vigorously, with manual instrumentation. The teeth were divided ramdomically in several groups: GI -- control, just manual instrumentation and water irrigation; GII -- manual instrumentation, EDTA irrigation; GIII -- manual instrumentation, EDTA irrigation, Er:YAG laser irradiation; GIV -- manual instrumentation, laser irradiation; and, GV -- manual instrumentation, laser irradiation and EDTA. Kruskall Wallis statistical test was applied and shows that there was not significance difference at the level of 5% among the five groups, however, when the groups were compared in pairs, GII X GIV and GII X GV shows difference in 5%, and GI X GII, difference at 1% level. The results show equivalence around the used methodology.
Human enamel tissue has been exposed to Nd:YAG pulsed laser operating in nanosecond and picosecond pulse regime. Morphological comparison between the regimes of operation have been investigated special attention to preservation of structure was taken. Trains of pulses with picosecond duration from a Q-switched and mode-locked Nd:YAG laser and pulses with nanosecond duration from a Q-switched Nd:YAG laser both operating at 15 Hz kept at in same average power, were focused in human sound molar during 30 s. Drilled holes with different morphological characteristics were observed for several laser intensity regime. Enamel surfaces were examined in a scanning electron microscope and their morphological characteristics compared. Contrast between the morphology of the enamel when treated with different powers and lasers pulse duration were observed. Picosecond pulses promote a better defined material removal while nanosecond pulses at the equivalent average power level causes a large intermediate modified region between ablated and normal tissue, as well as a complete superficial modification of the existent original structure. Results show an important correlation between the surface morphology and the pulse width of the lasers, giving indications towards the use of ultrashort laser pulses in Dentistry.
KEYWORDS: Nd:YAG lasers, Laser dentistry, Adhesives, Composite resins, Composites, Teeth, Laser systems engineering, Dentistry, In vitro testing, High power lasers
The authors evaluated, in vitro, the tensile strength of a hydrophilic adhesive on dentin surface, with and without previous treatment with high power Nd:YAG laser. Power of 1.0 W and 2.0 W with respective frequencies of 25 Hz and 50 Hz were used. Thirteen human extracted molars were prepared and randomly separated in five groups: GI, Nd:YAG laser with 1.0 W plus SBMPP (3M) adhesive system; GII, laser with 2.0 W, plus adhesive system; GIII, laser with 1.0 W; GIV, laser with 2.0 W; GV, adhesive system to treat dentin surface. To each group five samples with a composite bottom each, totalling in 25 samples, which were kept in distilled water, by 37°C, during 30 days. After that, thermal cycling was applied. After this period, the samples were submitted the tensile strength test to evaluate the necessary threshold of power to break up the adhesive bond of composite button from dentin surface. The statistical evaluation was done through variance analysis. Results showed that the values of tensile strength of the GV (26.4 kgf/cm2) were better than GI (4.6 kgf/cm2) which was the best laser group: GIII (2.4 kgf/cm2); GII (1.7 kgf/cm2) and GIV (1.2 kgf/cm2).
The objective of this present work to evaluate in the level of pain and tumor the effect of the low-power density laser irradiation of GaAlAs 790 nm in implanted patients during the postoperative period. Forty five clinic situations were selected and divided in three different groups: Group I, control, without laser application, but with analgesic and anti-inflammatory medication; Group II, patients were irradiated on the day of the surgery, after the same concluded, and on the two subsequent days; and Group III, patients were irradiated on the day of the surgery, on the day of the surgery, before and after the end of the same, and in the two subsequent days after. All the applications were accomplished using the same energy parameters and by the same operator. The measures, with relationship to the pain and the tumor, they were accomplished in the immediate postoperative, in the postoperative (24 hours and also 72 hours after) always by the same examiner. The statistical analysis sustained the clinic observations. In our study, the low power density laser of GaAlAs 790 nm suggested the same clinical results when pain and tumor formation were controlled by analgesic and anti- inflammatory medication.
The aim of the present work was to evaluate histometrically the effect of the irradiation with semiconductor diode GaAlAs 790 nm low-powered laser in the chronology of alveolar repair of rats. Lasers of low intensity possesses an eminently analgesic, anti-inflammatory and bioestimulant effect, producing an increase of the local micro-circulation and in the speed of healing. Groups of five animals had their upper right incisors extracted under anesthesia and the mucous sutured; three groups received 1.5 J/cm2 of irradiation immediately after the extraction with laser for sweeping on the operated area. After that, the animals were sacrificed in the periods of 7, 14 and 21 days after the dental extraction. The material was decalcified and processed for inclusion in paraffin. Longitudinal sections of 7 micrometers in the alveolus were made and stained with HE. The histometric analysis was performed with the Merz grid, and 2000 points were counted in each cervical, middle and apical thirds of the alveolus, assessing the percentage of the bone tissue. The result shows that low-powered intensity laser produced acceleration in osseous formation (10%) in some periods.
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