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Objective: The aim of this study was to analyze the microhardness of demineralized enamel following different treatments (fluoride varnish, Er:YAG laser, and Er:YAG laser associated with fluoride v...

Objective: This in vivo study compared two bleaching techniques with regard to the degree of tooth sensitivity (TS), color change, and treatment stability for a 6-month follow-up period. Materials ...

Background: The diagnosis of sleep bruxism (SB) in children is difficult due to the lack of a polysomnographic protocol for this population. Moreover, the gold standard treatment [occlusal splint (...

Objective: To clinically evaluate the effect of the violet light-emitted diode (LED) light (405–410 nm) associated to in-office dental bleaching with 35% carbamide peroxide, on tooth color change a...

Aim: To evaluate the fracture resistance of roots restored with CAD/CAM-fabricated posts, receiving or not intracanal laser treatment, compared with glass fiber posts under mechanical cycling. Methods: Twenty-seven endodontically treated, single-rooted teeth were divided into 3 groups: group 1 (control), prefabricated glass fiber posts relined with resin composite; group 2, CAD/CAM-fabricated intraradicular posts using Resin Nano Ceramic (RNC) blocks; and group 3, CAD/CAM-fabricated intraradicular posts using RNC blocks in canals irradiated with a 940-nm diode laser (100 mJ, 300-um optic fiber, coronal-apical and apical-coronal helical movements, speed of 2 mm/second, 4 times each canal). After cementation of the coping, cyclic loading was applied at an angle of 135° to the long axis of the root, with a pulse load of 130 N, frequency of 2.2 Hz, and 150,000 pulses on the crown at a point located 2 mm below the incisal edge on the lingual aspect of the specimen. Every 50,000 cycles, the specimens were evaluated for root fracture occurring below or above the simulated bone crest. Results were analyzed by one-way ANOVA followed by Tukey’s test (p

Introduction: Microleakage has been reported to cause dentin hypersensitivity because of the passage of bacteria and their products through the restoration-tooth interface and is one of the main reasons for replacement of restorations. CO2 laser can be used for treatment of dentin hypersensitivity. Thus, this study aimed to evaluate in vitro the microleakage in composite restorations following surface pretreatment with acid etching and CO2 laser. Methods: Twelve human caries-free primary molars were selected. Class II cavities were prepared on occlusal mesial and occlusal distal surfaces. Specimens were randomly divided into four groups (n=6): Group 1 (G1) – 37% phosphoric acid gel etching + Beautiful-Bulk Restorative – Giomer (Shofu Inc); Group 2 (G2) – 37% phosphoric acid gel etching + SDR Bulk-Fill Flow (Dentsply); Group 3 (G3) – CO2 laser irradiation + Beautiful-Bulk Restorative – Giomer (Shofu Inc); Group 4 (G4) – CO2 laser irradiation + SDR Bulk-Fill Flow (Dentsply). Surfaces were restored with bonding agent (Natural Bond DE, DFL). Specimens were cut longitudinally and immersed in 0.5% methylene blue solution for 4 hours. Microleakage scores were assessed under a magnifying glass at x3,5 and qualitatively analyzed by scanning electron microscope (SEM). Data were analyzed using nonparametric Wilcoxon test (P < 0.05). Results: Scores prevailed between 0 and 2, however, no statistically significant difference was found among the groups (P= 0.05). Conclusion: It could be concluded that all composite resins bulk fill did not show significant difference among them regarding microleakage using either CO2 laser or 37% phosphoric acid etching.

Interdental papilla is of major importance to patients' orofacial aesthetics, especially regarding anterior teeth as part of the smile's harmony. Loss of gingival tissue, which constitutes interdental papilla, forms what in odontology is called black spaces. This loss, besides affecting the smile's aesthetics, also provokes phonetic and functional damage.The objective of the authors is to present the result of three clinical cases treated with an innovative technique called hemolasertherapy, which stimulates growth of gingival papilla and thus permanently fills in the black spaces.The photobiomodulation therapy (PBMT) used a 660 nm diode laser (Laser Duo, MMO-São Carlos, SP, Brazil), punctual, contact mode in two steps: before the bleeding (first PBMT) and immediately after bleeding (second PBMT). Parameters used were power output: 100 mW, CW; diameter tip: 5 mm; spot area: 0.19 cmThis initial study demonstrated that the blood clot originated from the bleeding provoked in the gingival area is rich in mesenchymal stem cells. PBMT enables preservation, viability, and further differentiation, stimulating the return of gingival stem cells, which would support their survival and differentiation in the blood clot, thus favoring interdental papilla regeneration.Follow-up was done for a time span of 4-5 years and considered excellent with regard to papilla preservation.

The aim of this study was to evaluate the effect of phototherapy on bite force, facial swelling, mandibular movements, and pain in patients having undergone surgical treatment for mandibular fractures.These are among the predominant types of facial fractures, and treatment involving surgical fixation with titanium plates is one of the most common procedures in oral-maxillofacial surgery. Phototherapy has been used to accelerate the muscle healing process and significantly improves muscle regeneration by inducing the formation of new muscle fibers.The patients were divided into two groups: Group 1-active phototherapy, and Group 2-sham phototherapy. Both groups underwent the surgical procedure by the same surgeon using the same surgical technique. Dosimetric parameters are wavelength, 660 nm; power, 108 mW; radiant energy, 21.6 J; fluency, 21.6 J/cmThe primary variable was bite force measured with a gnathodynamometer and the secondary variables were facial swelling, mandibular movements (measured with digital calipers), and pain. The Student's t-test was used to determine intergroup differences.The findings suggest improvements in the laser group in comparison with the sham group with regard to mandibular dynamics, a reduction in postoperative facial swelling, a reduction in pain, and an increase in bite force.

Made available in DSpace on 2018-12-11T16:45:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-02-01 Objective: In this study, we aim to compare the photodynamic inactivation (PDI) effects of two different photosensitizers (PS), Photogem® and Natural Curcumin, irradiated with light-emitted diodes (LED) at 630 and 450 nm, respectively. Background: The current antimicrobial mouthwash for oral hygiene has several drawbacks. In this context, PDI is an alternative technique to inactivate pathogenic microbes in mucosa and in periodontal tissue. Furthermore, there are numerous infectious diseases that may affect the oral cavity, motivating the use of PDI in dentistry. Methods: The volunteers (n = 50) were randomize separated into five experimental groups (n = 5) for each PS: water control, PS control, light control, and two PS concentrations (25 and 100 mg/L). Each patient underwent mouthwash solution containing the PS before illumination procedure that was performed with an LED device. For microbial decontamination evaluation, the saliva was collected three times: before (T0), immediately after (T1), and 24 h after the illumination procedure (T2). After that, the difference between the colony forming units (CFU) for each volunteer was compared. Results: The results show that regardless of PS and treatment applied, there was microbial reduction immediately after PDI, however, after 24 h only Natural Curcumin still presents a reduction. For Photogem after 24 h, the microorganism returns to the original CFU. Conclusions: Immediately after PDI, both PS have the same efficiency, nevertheless the Natural Curcumin still has an efficacy after 24 h and also is a more viable photosensitizer. In addition, the results indicate that PDI can be a promised technique used for microbial reducing for the oral cavity. School of Dentistry of Araraquara UNESP University of Estadual Paulista São Carlos Institute of Physics University of São Paulo, PO Box 369 Biomedical Engineer Research Center CEB Camilo Castelo Branco University School of Dentistry of Araraquara UNESP University of Estadual Paulista

Background and aims: One of the major side effects of vital bleaching is the reduction of enamel micro-hardness. The purpose of this study was to evaluate the influence of two different bleaching systems, Plasma Arc and GaAlAs laser, on the enamel micro-hardness. Materials and methods: 15 freshly extracted human third molars were sectioned to prepare 30 enamel blocks (5×5 mm). These samples were then randomly divided into 2 groups of 15 each (n=15): a plasma arc bleaching group (: 350–700 nm) + 35% Hydrogen Peroxide whitening gel and a laser bleaching group (GaAlAs laser, λ: 810 nm, P: 10 W, CW, Special Tip) + 35% Hydrogen Peroxide whitening gel. Samples were subjected to the Vickers micro-hardness test (VHN) at a load of 50 g for 15s before and after treatment. Data were statistically analyzed by a Mann-Whitney test (p≤0.05). Results: In the GaAlAs laser group, the enamel micro-hardness was 618.2 before and was reduced to 544.6 after bleaching procedures. In the plasma arc group, the enamel micro-hardness was 644.8 before and 498.9 after bleaching. Although both techniques significantly reduced VHN, plasma arc bleaching resulted in a 22.62% reduction in VHN for enamel micro-hardness, whereas an 11.89% reduction in VHN was observed for laser bleaching; this difference is statistically significant (p

The aim of this work was to verify the existence of correlation between Raman spectroscopy readings of phosphate apatite (∼960 cm−1), fluoridated apatite (∼575 cm−1) and organic matrix (∼1450 cm−1) levels and Diagnodent® readings at different stages of dental caries in extracted human teeth. The mean peak value of fluorescence in the carious area was recorded and teeth were divided in enamel caries, dentin caries and sound dental structure. After fluorescence readings, Raman spectroscopy was carried out on the same sites. The results showed significant difference (ANOVA, p

Oral biology, oral pathology, and oral treatments are interesting fields in dentistry. The rapid evolution of technologies and the continuous apparition of new materials and products available for practitioners oblige searchers to evaluate their impact on oral tissues and teeth. The evaluation of the biocompatibility of new products is essential to avoid any tissues damage caused by an eventual toxicity or side effects of therapeutic products or materials.

To assess the temperature variation in the cervical, middle and apical thirds of root external wall, caused by 980-nm diode laser irradiation with different parameters.The roots of 90 canines, had their canals instrumented and were randomly distributed into 3 groups (n=30) according to the laser potency (1.5 W, 3.0 W and 5.0 W). Each group was subdivided into 3 (n=10) according to the frequency (CM, 100 Hz and 1000 Hz), and each subgroup divided into 2 (n=5): dried canal or filled with distilled water. The maximum temperature values were collected by 3 thermocouples located at each third of the root external wall and recorded by digital thermometers.The groups irradiated in the continuous mode (CM) presented the highest values (11.82+/-5.78), regardless of the canals were dry or not, which were statistically different (p0.01) from those obtained with 100 Hz (6.22+/-3.64) and 1000 Hz (6.00+/-3.36), which presented no statistical difference between them (p0.01). The groups irradiated with 5.0 W presented the greatest temperature variation (12.15+/-5.14), followed by 3.0 W (7.88+/-3.92) and 1.5 W (4.02+/-2.16), differing between them (p0.01). The cervical third of the root presented the highest temperature rises (9.68+/-5.80), followed by the middle (7.66+/-4.87) and apical (6.70+/-4.23), with statistical difference among them (p0.01). After 30s from the end of irradiation, all the specimens presented temperature variation lower than 10 degrees C.Application of 980-nm diode laser in the root, at 1.5 W in all operating modes, and 3.0 W, in the pulsed mode, for 20s, can safely be used in endodontic treatment, irrespective of the presence of humidity.

This study evaluated, in vitro, the degree of disinfection of the Er:YAG laser in root canals contaminated with Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, and Candida albicans, for 28 days.Forty-six single-rooted human teeth were divided into five groups of eight teeth each; three teeth were used as negative controls and three as positive controls. After contamination, the root canals were prepared mechanically. Three groups were irradiated with Er:YAG laser at 100 mJ, varying the frequency (7, 10, and 16 Hz). Two groups were irrigated with 1.0% and 2.5% NaOCl solution. After treatment, two sterilized paper cones were placed in the root canals for 5 min. One cone was transferred to 2.0 mL of Letheen broth culture medium, incubated at 37 degrees C for 48 h, and then 0.1 mL of that solution was placed in 2.0 mL of brain heart infusion for 48 h to determine microbial growth. The other cone was transferred to a test pipette with peptone and water for serial dilution and spread in Müeller Hinton medium. After 24 h of incubation, the colony-forming units (CFUs) were counted.There was a microbial reduction of 85.33% for the group irradiated with Er:YAG laser at 100 mJ/7 Hz, 74.58% at 100 mJ/10 Hz, and 89.50% at 100 mJ/16 Hz. For the groups irrigated with 1.0% and 2.5% NaOCl solution, 83.15% and 84.46% values of microbial reduction were obtained respectively.All the groups showed statistically similar results (p0.05%). No method totally eliminated microorganisms.

Background and Objectives Smear layer removal with EDTA from root canal walls allows greater cleaning and disinfection of root canals. However, because Er:YAG laser acts on the removal of the smear layer, the objective of investigation was to analyze in vitro the effect of Er:YAG laser on dentin root canal wall permeability after endodontic instrumentation and irrigation with water or sodium hypochlorite and Er:YAG laser application. Study Design/Materials and Methods A total of 25 extracted human maxillary incisors were divided into five groups: Group I, instrumentation with deionized distilled water as the irrigating solution; Group II, instrumentation with 1% sodium hypochlorite as the irrigating solution; Group III, instrumentation with deionized distilled water as the irrigating solution and Er:YAG laser application; Group IV, instrumentation with 1% sodium hypochlorite solution as the irrigating solution and Er:YAG laser application; Group V, instrumentation only up to #20 file with deionized distilled water as the irrigating solution and Er:YAG laser irradiation. The laser parameters were 15 Hz, 140 mJ, total energy 42 J, 300 pulses (Kavo Key Laser). Copper sulfate (10%) was used to evaluate dentin permeability. The penetration of copper ions into the dentinal tubules was observed using 1% rubeanic acid, which reveals copper ions, forming a stained compound ranging in color from deep blue to black. Transverse sections (500-μm thick) were obtained with a diamond disk from the cervical, middle, and apical thirds. Results The instrumentation of the root canal that used water as the irrigating solution followed by Er:YAG laser irradiation promoted the greatest increase in dentin permeability. The use of Er:YAG laser, 1% sodium hypochlorite + Er:YAG, and 1% sodium hypochlorite used alone showed an intermediate capacity of increasing dentin permeability. The use of water as the irrigating solution without Er:YAG laser promoted the least dentin permeability. Conclusions The use of water as the irrigating solution after instrumentation and Er:YAG laser irradiation was an effective procedure for increasing dentin permeability. Lasers Surg. Med. 26:277–281, 2000. © 2000 Wiley-Liss, Inc.

Dentinal hypersensitivity has been studied for several years. It is reported as a strikingly painful condition that originates from the exposure of dentinal tubuli when the thickness of the enamel or cement is significantly reduced. Usually the exposed area is subjected to several kinds of stimuli, resulting in sharp acute pain. The aim of this study was to evaluate the efficacy of low level laser therapy (LLLT) in the treatment of patients with dentinal hypersensitivity. A total of 1102 teeth of 388 patients were treated with LLLT between 1995-2000. Ninety-eight males and 290 females aged 30 to 45 years old were treated. For LLLT, a 780nm continuous wave diode laser was used at an output of 40mW, elliptical area of the beam, 2mm2, and exposure time per point of 25s. This corresponds to an equivalent dose of 50 J/cm2 at each point (considering the area of the spot). If a 1 cm2 area is considered, the total dose per tooth was 4J/cm2. With the 830nm CW 50mW diode laser, the elliptical area of the beam was 2mm2, and exposure time per point was 20s. This corresponds to an equivalent dose of 50J/cm2 at each point (considering the area of the spot). If a 1cm2 area is considered, the total dose per tooth was 4J/cm2. The results showed 403 (36.57%) out of 1102 teeth required a single session for complete remission of the symptom, 255 (23.14%) needed two sessions; 182 (16.51 %) three sessions; 107 (9.7%) four sessions; and 59 (5.35%) five sessions. Ninety-six (8.71%) did not respond to LLLT and the patients were re-assessed and treatment changed. The more affected tooth was the lower premolar (301 - 27.4%), followed by lower molars (163 - 14.8%), upper premolar (149 - 13.5%), lower incisive (148 - 13.4%), upper canine (119 - 10.7%), upper incisive (108 - 9.9%), lower canine (62 - 5.6%), and upper molars (52 - 4.7%). The result of the present investigation demonstrates that LLLT, when used with the correct irradiation parameters, is effective in treating dentinal hypersensitivity, as it quickly reduces pain and maintains a prolonged pain-free status in 91.27% of the cases. Previous studies carried out by the authors examined the histological reaction of the dentinal pulp in rats after application of LLLT. The LLLT was shown to be effective in stimulating odontoblasts, producing repaired dentine and closing dentine tubuli.

The simultaneous need for infection-control protocols in sample preparations and for safe laser irradiation parameters prompted this study about the effects of heat produced by both sample sterilization and laser etching on dentin components. The dentin was exposed on 30 bovine incisors, and then divided into two main groups: autoclaved (group A) or thymol treatment (group B). The surface of the dentin was schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid (control-CG) or irradiated with Er:YAG laser (subgroups: I- 80 mJ, II-120 mJ, and III-180 mJ). Elemental distribution maps were done by energy-dispersive X-ray fluorescence (μ-EDXRF) on each treatment area. The dentin surface in depth was exposed and line-scan maps were performed. The B_CG treatment produced the best distribution of calcium (Ca) and phosphorus (P) content throughout the dentin surface. Er:YAG laser etching produced irregular patterns of elemental distribution in the dentin. Laser energies of 120 and 180 mJ produced the highest maximum calcium values. The Er:YAG laser energy of 180 mJ produced a localized increase in Ca and P content on the superficial layer of the dentin (∼0-0.10 mm). The auto- claving treatment of samples in experiments is not recommended since it produced damaging effects on dentin components. Er:YAG laser irradiation produced a hetero- geneous Ca and P distribution throughout the dentin surface with areas of increased Ca concentration, and this may affect clinically the permeability, solubility, or adhesive characteristics of dental hard tissues with restorative procedures.

In vitro studies have provided conflicting evidence of temperature changes in the tooth pulp chamber after low-level laser irradiation of the tooth surface. The present study was an in vitro evaluation of temperature increases in the human tooth pulp chamber after diode laser irradiation (GaAlAs, λ = 808 nm) using different power densities. Twelve human teeth (three incisors, three canines, three premolars and three molars) were sectioned in the cervical third of the root and enlarged for the introduction of a thermocouple into the pulp chamber. The teeth were irradiated with 417 mW, 207 mW and 78 mW power outputs for 30 s on the vestibular surface approximately 2 mm from the cervical line of the crown. The highest average increase in temperature (5.6°C) was observed in incisors irradiated with 417 mW. None of the teeth (incisors, canines, premolars or molars) irradiated with 207 mW showed temperature increases higher than 5.5°C that could potentially be harmful to pulp tissue. Teeth irradiated with 78 mW showed lower temperature increases. The study showed that diode laser irradiation with a wavelength of 808 nm at 417 mW power output increased the pulp chamber temperature of certain groups of teeth, especially incisors and premolars, to critical threshold values for the dental pulp (5.5°C). Thus, this study serves as a warning to clinicians that “more” is not necessarily “better”.

Failures in the sealing of the tooth apex have been considered to be responsible for most of the failures of apical surgeries. The Er:YAG laser has been proposed as an alternative for the use of rotator instruments in surgical endodontics due to its precision, lack of vibration, less post-operative discomfort, bacterial reduction, and less stress for patients and professionals. Following approval by the ethics committee, 12 extracted human canines without previous endodontic treatment with anatomically normal roots and free from apical lesions were washed in running tap water and disinfected. The teeth were sectioned axially at the crown-root junction and submitted to routine endodontic treatment. The apical limit was set at 1 mm before the apical foramen. The root canals were routinely filled with Gutta-Percha points and Sealer 26 and were randomly distributed into two groups (n = 6). In group I, apicectomy was performed with the Er:YAG laser (KAVO KEY Laser II®, Germany, λ = 2.940 nm, pulsed mode, 2051 tip, with air spray cooling, 250 mJ/15 Hz). Apical cut was performed of perpendicular mode 3 mm from the apical foramen. In group II, the same procedures and the same sequence as above was used, varying only the parameters of the Er:YAG laser (400 mJ/6 Hz). Sealing of the cervical end the apex was carried out with acrylic resin; the roots were covered by a layer of epoxy glue and two layers of nail polish. The specimens were divided into groups and fixed, by the cervical third, on wax. Impermeabilization of the residual root apical third was performed following the same procedures used in the cervical third but the residual apex was left free from the impermeabilization. After that, the roots were immersed in a 2% methylene blue solution and placed in a bacteriological oven for 48 h and then washed in running tap water for 2 h. The samples were sagittally split into two parts. The segments were visually observed and the one showing the greatest level of dye leakage was selected and kept in an individual container and coded accordingly. Apical staining was measured using a stereoscopic magnifying glass, a compass, and a caliper. The measurement was performed by three endodontists, previously calibrated, and unaware of the sample coding. The results showed that group I showed the greatest level of dye leakage. There was a significantly difference between the groups (p = 0.001). It is concluded that the apicectomies carried out with 400 mJ/6 Hz showed the smallest infiltration value.

Aim To evaluate the bond strength of AH Plus and Epiphany sealers to human root canal dentine irradiated with a 980 nm diode laser at different power and frequency parameters, using the push-out test. Methodology Sixty canine roots were sectioned below the cementoenamel junction to provide 4-mm-thick dentine discs that had their root canals prepared with a tapered bur and irrigated with sodium hypochlorite, ethylenediaminetetraacetic acid and distilled water. The specimens were assigned to five groups (n = 12): one control (no laser) and four experimental groups that were submitted to 980 nm diode laser irradiation at different power (1.5 and 3.0 W) and frequency (continuous wave and 100 Hz) parameters. Half of specimens in each group had their canals filled with AH Plus sealer and half with Epiphany. The push-out test was performed and data (MPa) were analysed statistically by anova and Tukey’s test (P

This study evaluated the effect of 980-nm diode laser at different parameters on root canal dentin permeability associated with different irrigants. Seventy-five canines were sectioned at 15 mm from the apex, prepared mechanically up to #40 .02 instrument, and irrigated with 2 mL distilled water. Final irrigation (10 mL) was used as follows: (1) distilled water; (2) 1% NaOCl; (3) 17% ethylenediaminetetraacetic acid + a cationic surfactant cetyltrimethylammonium bromide (EDTAC). Laser was applied at 1.5 or 3.0 W as either continuous wave or pulsed wave (100 Hz). The teeth were then processed histochemically, the percentage of copper ion penetration into the dentin of the canal walls was counted, and the data were analyzed statistically with the Tukey-Kramer test (alpha < .01). When laser was associated with water, an increase in permeability was found, whereas permeability decreased when associated with EDTAC. Dentin permeability after laser irradiation was directly dependent on the solution used for final irrigation.

Cervical dentine hypersensitivity is the most frequent complaint among reported odontalgias. Thus, this study evaluated the effectiveness of two types of lasers (660 nm wavelength red, and 830 nm wavelength infrared) as dentine desensitizers, as well as both the immediate and late therapeutic effects in individuals 25 to 45 years of age. A total of 40 teeth with cervical exposure were treated in 4 sessions. They were divided into 2 groups according to treatment. A 660 nm wavelength red diode laser and an 830 nm wavelength infrared diode laser were used. Dentine sensitivity to cold nociceptive stimulus was evaluated by means of a pain numeric scale from zero to 10 before each treatment session, at 15 and 30 min after irradiation, and in a follow-up period of 15, 30 and 60 days after the end of treatment. Significant levels of dentinal desensitization were only found in patients ranging in age from 25 to 35 years. The 660 nm red diode laser was more effective than the 830 nm infrared laser and a higher level of desensitization was observed at the 15 and 30 minute post-irradiation examinations. The immediate and late therapeutic effects of the 660 nm red diode laser were more evident in 25-35-year-old patients compared with those of the 830 nm infrared diode laser, in terms of the different age groups. A hipersensibilidade dentinária cervical é a queixa mais frequente entre os relatos de odontalgia. Este estudo avaliou a eficácia de dois tipos de lasers, vermelho com 660nm e infravermelho com 830nm de comprimento de onda, como dessensibilizadores dentinários, como também os efeitos terapêuticos imediato e tardio em indivíduos de 25 a 45 anos de idade. Um total de 40 dentes com exposição cervical foram tratados em 4 sessões, divididos em 2 grupos - laser vermelho e infravermelho. A sensibilidade dentinária ao estímulo nociceptivo frio foi avaliada por meio de uma escala numérica de dor, de 0 a 10, antes de cada sessão de tratamento, aos 15 e 30 minutos após a irradiação e num período de seguimento de 15, 30 e 60 dias após o término do tratamento. Níveis significantes de dessensibilização dentinária foram apenas encontrados em pacientes com idade entre 25 a 35 anos. O laser díodo vermelho de 660nm foi mais eficaz comparado com laser infravermelho de 830nm e foi observado um nível mais alto de dessensibilização nas mensurações realizadas aos 15 e 30 minutos após irradiação. O efeito terapêutico imediato e tardio do laser díodo vermelho de 660nm é maior quando comparado com o infravermelho de 830nm em ambas faixas etárias.

This study determine, in vitro, the coronal leakage of root canals evaluating the effect of smear layer removal by either EDTA or laser. Two sealers were also compared. Sixty- four canines were instrumented with the step-back technique and irrigated with 10 ml of 1% sodium hypochlorite. In Group 1, 10 teeth were sealed with Sealer 26 and 10 teeth were sealed with Grossman cement with no attempt of smear layer removal. Group 2 received a final irrigation of 15 ml of 15% ETA, and was sealed as in group 1. Group 3 received Er:YAG laser application (2940 nm, 140 mJ, 15 Hz and 42 J, 300 pulses, 500milli-sec pulse duration), and sealed as in group 1. Root canals sealed with Sealer 26 has significantly less coronal leakage than Grossman cement (p 0.01).

The effects of laser etching, decontamination, and storage treatments on dentin components were studied using Fourier trans- form FT-Raman spectroscopy. Thirty bovine incisors were prepared to expose the dentin surface and then divided in two main groups based upon the decontamination process and storage procedure: au- toclaved group A, n=15 or stored in thymol aqueous solution group B, n=15. The surfaces of the dentin slices were schematically divided into four areas, with each one corresponding to a treatment subgroup. The specimens were either etched with phosphoric acid control subgroup or irradiated with erbium-doped yttrium- aluminum-garnet Er:YAG laser subgroups: I-80 mJ, II-120 mJ, and III-180 mJ, and total energy of 12 J. Samples were analyzed by FT- Raman spectroscopy; we collected three spectra for each area before and after treatment. The integrated areas of five Raman peaks were calculated to yield average spectra. The areas of the peaks associated with phosphate content P0.001, type I collagen, and organic C-H bonds P0.05 were reduced significantly in group A control. Analyses of samples irradiated with reduced laser energies did not show significant changes in the dentin components. These results sug- gest that thymol storage treatment is advised for in vitro study; further- more, 12 J of Er:YAG laser energy does not affect dentin components. © 2009 Society of Photo-Optical Instrumentation Engineers. DOI: 10.1117/1.3103285