In Vitro Evaluation of the Effectiveness of Dental Bleaching with Carbamide Peroxide and Violet Light.

Objective: The aim of the current study was to use the CIELab system to evaluate the performance of the whitening treatment involving violet light-emitting diode (LED) combined with a home 10% and 22% carbamide peroxide dental bleaching technique on dental enamel. Methods: Fifty blocks of bovine dental enamel were divided into five groups: control group (control), receiving only LED irradiation; Whitening 10%, receiving 10% carbamide peroxide treatment; Whitening 10%+VL, receiving 10% carbamide peroxide treatment combined with LED irradiation; Whitening 22%, receiving 22% carbamide peroxide treatment; and Whitening 22%+VL, receiving 22% carbamide peroxide treatment combined with violet LED irradiation. Color tests were performed before the protocols, after 1 week and after 2 weeks of treatment by using a spectrophotometer and the CIELab parameters: L*, (a*) and (b*). The Whitening 10%, Whitening 10%+VL, Whitening 22% and Whitening 22%+VL groups were submitted to 10% and 22% carbamide peroxide 8 h per day for 14 days, whereas the Control was only stored in artificial saliva. For irradiation in the Control, Whitening 10%+VL, and Whitening 22%+VL groups, we used violet LED at a wavelength of 405-410 nm activated for 60 permanent seconds and 30 sec of pause once per week. As all data exhibited normal distribution, the comparisons were performed by using two-way repeated-measures analysis of variance. A post hoc t-test was employed, followed by the Ryan-Holm stepdown Bonferroni procedure. Results: After 1 week, the Whitening 22%+VL group differed significantly from all other groups in relation to hue, while no difference was found between the remaining groups (p < 0.05). Analyzing lightness, the Whitening 22%+VL and Whiteness10%+VL groups differed from the other groups (p > 0.05). In the 2nd week, the Whitening 22%+VL groups differed significantly from all other groups (p < 0.05) in hue, chroma, and lightness. The comparative analysis of bleaching times within the same group revealed significant differences in the Whitening 22%+VL group between baseline and week 1, baseline and week 2, as well as weeks 1 and 2 in terms of hue (p > 0.05). In the Whitening 22%+VL group, significant differences (p < 0.05) were found between baseline and week 2 as well as between weeks 1 and 2 in chroma (p > 0.05). In the Whitening 22%+VL group, statistically significant differences (p < 0.05) were found between baseline and week 1, baseline and week 2, as well as between weeks 1 and 2 in lightness. In the Whitening 10%+VL group, statistically significant differences (p < 0.05) were found between baseline and week 1, between baseline and week 2, as well as between weeks 1 and 2 in lightness. Conclusions: Tooth whitening treatment involving 10% and 22% carbamide peroxide combined with violet light promoted changes in the three axes of color (ΔH, ΔC, and ΔL) of the specimens evaluated. The use of the gel bleach alone was more efficient when the higher concentration was used. When violet light was combined with the gel, the lower concentration was more efficient.

Clinical evaluation of in-office tooth whitening with violet LED (405 nm): A double-blind randomized controlled clinical trial.

BACKGROUND: Although there is little evidence showing the effectiveness of violet LED on in-office tooth whitening, there are some studies which have reported satisfactory results. This double-blind randomized controlled clinical trial aimed to evaluate the effect of a violet light emission diode (LED) (405 nm) system, used in-office, on tooth whitening, sensitivity, use of medication after whitening and quality of life. METHODS: Eight patients were randomized into 4 groups (n = 20): G1 - violet LED, G2 - 35% carbamide peroxide (CP) and violet LED, G3 only CP 35% and G4 35% hydrogen peroxide (HP). The color was measured using a spectrophotometer at the following times: baseline, 15 and 180days. The colorimetric changes were analyzed using measurements from the CieLab System ΔE (ΔL, Δa and Δb) and the WID (Whiteness Index for Dentistry) for the 4 groups. Tooth sensitivity was recorded via a visual analog scale (VAS). Additionally, the Psychosocial Impact of Dental. Aesthetics Questionnaire (PIDAQ) was used to evaluate quality of life. RESULTS: For the analysis of ΔL, G4 and G2 presented more brightness than G1 and G3 (p<0.05), implying that G2 is at least as good as G4 (p>0.05). For measure of Δa, G4 presented better results, standing out from the other groups. (p<0.05). For Δb, both G4 and G2 showed a greater tendency for blue color than groups G1 and G3 (p <0.05). When analyzing ∆E at the 180-day follow up, G4 produced the highest ∆E, while G3 showed the lowest ∆E. The other 2 whitening groups produced intermediate ∆E values. For ∆W, G1 and G3 significantly differed from G2 and G3. When analyzing the 180-day follow up, G2 produced the highest ∆W, while G3 showed the lowest ∆W. The other two whitening treatments produced intermediate ∆W values. As for sensitivity, only G4 patients showed dental sensitivity within 24 h of the bleaching, with pain ceasing after 48 h. For G4, 33% of the patients needed to take analgesics within the first 24 h after the first 3 whitening sessions. For PIDAQ, there was no overall decrease in score over time for any of the groups and there was no difference between them (p>0.05). CONCLUSION: Our results showed that violet LED was not able to whiten teeth at the same intensity, when used alone, as it was when associated with 35% CP, contrary to our initial hypothesis. However, given that pain was not consistently reported in G2, one could suggest that treatment with LED + 35% CP is quite similar to that of 35% HP when used for tooth whitening, but with better pain outcomes. All treatments suggested an improvement in quality of life.Clinical Trial Registry: This trial is registered at ClinicalTrials.gov; the registration number is NCT03192852 https://clinicaltrials.gov/ct2/show/NCT03192852.

Effect of Er:YAG Laser and Association of Protocols on the Demineralized Enamel Microhardness.

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 varnish). Methods: Forty-eight enamel blocks (4 × 4 × 7 mm) were divided into six groups (n = 8): (S) Sound; (DE) Demineralized; (DED) DE + Duraphat® 5% (fluoride varnish); (DEL20) DE + Er:YAG laser (20 mJ pulse mode; 0.20 W; 10 Hz; 60 sec; 1.18 J/cm2; 11.83 W/cm2); (DEL50) DE + Er:YAG laser (50 mJ pulse mode; 0.50 W; 10 Hz; 60 sec; 2.95 J/cm2; 29.58 W/cm2); (DEL20D) DE + Er:YAG laser (20 mJ) + Duraphat 5%. The irradiation was performed at 1 mm distance from the surface using a tip (AS7066X, L-14 mm, D-1.3 mm in diameter) in water/air spray refrigeration (level 6). The enamel blocks were submitted to pH cycling (4 h into DES solution +20 h into RE solution for 8 days and the solutions were changed every day). Knoop microhardness was measured (50 g/15 sec, six readings per sample) and data were analyzed by Kruskal-Wallis test at 5% significance. Results: After treatments, DF group showed higher microhardness values than all the groups. Also, DEL20D group showed similar results with H group according to the microhardness analysis (p < 0.05). Conclusions: It could be concluded that Duraphat 5% treatment showed better results when compared with all tested groups, however, the association of Er:YAG Laser 20 with Duraphat 5% also showed promising results.

Microleakage of "Bulk-Fill" Composite Resin for Class II Restorations Pretreated With CO2 Laser in Deciduous Molars: An In Vitro Study.

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.

Evaluation of in-office tooth whitening treatment with violet LED: protocol for a randomised controlled clinical trial.

INTRODUCTION: In-office tooth whitening treatment using violet light emited diode (LED) (405 nm) is a novel bleaching method that causes less sensitivity while offering the same effectiveness as the gold standard (35% hydrogen peroxide, H2O2). This study describes a protocol for the first randomised controlled clinical trial to compare the effects of the two methods. METHODS AND ANALYSIS: Eighty patients will be divided into four groups: G1 violet LED; G2 violet LED +35% carbamide peroxide; G3 35% H2O2 and G4 violet LED +gingivoplasty. Colour will be measured at baseline, immediately after the first session and at the 15 and 180 days follow-up using the Vita Classical and the digital Easyshade V spectrophotometer (Vita, Zahnfabrik, Germany). Sensitivity after whitening will be measured using the Visual Analogue Scale at baseline and at each session in all groups and in all follow-ups. The tissue removed during gingivoplasty (G4) will be submitted to immunohistochemical analysis for the determination of inflammatory changes caused by violet LED. The Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) will be evaluated before, as well as at established time point controls. The results will be expressed as mean and SD values. After determining the normality of the data, a one-way repeated-measures analysis of variance will be used for the comparison of data with normal distribution and the Kruskal-Wallis test will be used for data with non-normal distribution. A p<0.05 will be considered indicative of statistical significance. After determining the normality of the data, the Kruskal-Wallis test will be used for non-parametric data. Multivariate analysis of variance (MANOVA) and the Wilcoxon test will be used for comparing data from the PIDAQ. ETHICS AND DISSEMINATION: This protocol has been approved by the Human Research Ethics Committee of UniversidadeNove de Julho (certificate: 2.034.518). The findings will be published in a peer-reviewed journal. TRIAL REGISTRATION NUMBER: NCT03192852; Pre-results.

Use of laser fluorescence in dental caries diagnosis: a fluorescence x biomolecular vibrational spectroscopic comparative study.

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<0.05) between the fluorescence readings for enamel (16.4 ± 2.3) and dentin (57.6 ± 23.7) on carious teeth. Raman peaks of enamel and dentin revealed that ~575 and ~960 cm-1 peaks were more intense in enamel caries. There was significant negative correlation (p<0.05) between the ~575 and ~960 cm-1 peaks and dentin caries. It may be concluded that the higher the fluorescence detected by Diagnodent the lower the peaks of phosphate apatite and fluoridated apatite. As the early diagnosis of caries is directly related to the identification of changes in the inorganic tooth components, Raman spectroscopy was more sensitive to variations of these components than Diagnodent.

Use of laser fluorescence in dental caries diagnosis: a fluorescence x biomolecular vibrational spectroscopic comparative study

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<0.05) between the fluorescence readings for enamel (16.4 ± 2.3) and dentin (57.6 ± 23.7) on carious teeth. Raman peaks of enamel and dentin revealed that ∼575 and ∼960 cm−1 peaks were more intense in enamel caries. There was significant negative correlation (p<0.05) between the ∼575 and ∼960 cm−1 peaks and dentin caries. It may be concluded that the higher the fluorescence detected by Diagnodent the lower the peaks of phosphate apatite and fluoridated apatite. As the early diagnosis of caries is directly related to the identification of changes in the inorganic tooth components, Raman spectroscopy was more sensitive to variations of these components than Diagnodent.

O objetivo desse estudo foi verificar por meio da espectroscopia Raman, a existência de correlação entre os níveis de apatita fosfatada (∼960 cm−1), apatita fluoretada (∼575 cm−1) e matriz orgânica (∼1450 cm−1) e as leituras do Diagnodent® em diferentes estágios de cárie dental em dentes humanos extraídos. O valor médio do pico de fluorescência na área da cárie foi anotado e os dentes divididos em cárie de esmalte, dentina e dente hígido. Após as leituras de fluorescência, foi realizada a espectroscopia Raman nos mesmos sítios. Os resultados mostraram diferença significante (ANOVA p<0,05) entre as leituras de fluorescência para esmalte (16,4 ± 2,3) e dentina (57,6 ± 23,7) nos dentes cariados. Os picos Raman para esmalte e dentina evidenciaram que os picos ∼575 e ∼960 cm−1 foram mais intensos em cárie de esmalte. Houve correlação negativa e significante (p<0,05) entre os picos ∼575 e ∼960 cm−1 e cárie de dentina. Pode-se concluir que quanto maior a fluorescência detectada pelo Diagnodent menor o pico da apatita fosfatada e fluoretada. O diagnóstico precoce da cárie está diretamente relacionado com a identificação de mudanças nos componentes inorgânicos do dente, assim a espectroscopia Raman foi mais sensível para variações desses componentes quando comparada ao Diagnodent.

Influence of the parameters of the Er:YAG laser on the apical sealing of apicectomized teeth.

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.

Manifestações bucais e sistêmicas em crianças com doença hepática crônica / Oral and systemic findings in children with chronic liver diseases

Doença hepática crônica definida como lesão inflamatória do fígado, apresenta etiologias e graus de necrose e inflamação hepatocelular variados. Essas hepatopatias causam modificações bucais e sistêmicas pouco relatadas na literatura odontológica. Alterações na cavidade bucal como a pigmentação esverdeada de tecidos duros e moles, hipoplasia de esmalte e hipocalcificação são notadas em crianças com doença hepática crônica de tenra idade. Concomitante a essas mudanças observa-se algumas manifestações sistêmicas características, como a icterícia, xantomas e hepatoesplenomegalia. Dentre as opções terapêuticas para crianças com doença hepática crônica encontra-se o transplante hepático. Porém, para que se ocorra o ato cirúrgico é fundamental a intervenção do profissional da área odontológica, a fim de se eliminar e prevenir surgimento de focos infecciosos. Dessa forma, o presente trabalho oferece ao cirurgião dentista, em especial ao odontopediatra subsídios científicos para o diagnóstico e intervenção do profissional em crianças com doença hepática crônica.

Chronic liver disease defined as an inflammatory injury of the liver presents etiologies, varied necrosis degrees and hepatic cell inflammation. Those liver diseases result in oral and systemic findings seldom mentioned in the literature of dentistry. Mouth alterations such as green staining of hard and soft tissue, hypoplasia of enamel and hypocalcification changes are constantly seen in children. Concomitant to those changes it is possible to observe some systemic manifestations which are characteristics, such as jaundice, xanthoma and hepatosplenomegaly. Among the therapeutic options for children with chronic liver disease, there is the liver transplant. However for complete success of this surgical procedure it is extremely important the intervention of the dental surgery, in order to eliminate and prevent focus of infection. Based on that, the current study offers to the dentist and in special to the pedodontist, important scientific support for the diagnosis and intervention of these professionals in children with chronic liver disease.

Combined FT-Raman and SEM studies of the effects of Er:YAG laser irradiation on dentin.

OBJECTIVE: This study evaluated the molecular and morphological changes on dentin elements after Er:YAG laser irradiation. BACKGROUND DATA: Spectroscopy studies reporting the effects of Er:YAG laser irradiation as an alternative to acid etching are needed to better understand the laser's effects. METHODS: The occlusal one-third of the crown of six human third molars was removed. The dentin surface was schematically divided into areas corresponding to four surface treatment groups: control (group C): 37% phosphoric acid etching; group I: Er:YAG laser 80 mJ; group II: Er:YAG laser 120 mJ; and group III: Er:YAG laser 180 mJ. The analysis was performed by scanning electron microscopy (SEM) and Fourier transform Raman spectroscopy (FT-Raman) before and after the treatments. Raman data were submitted to ANOVA and Bonferroni tests. RESULTS: The SEM photomicrographs revealed open dentin tubules in the control group. The molars from groups I, II, and III showed partially open dentin tubules. SEM images showed that the laser-irradiated dentin surface was not favorable to the diffusion of monomers. A significant reduction of the spectra relative intensity was observed in group III specimens. CONCLUSIONS: Er:YAG laser irradiation with 180 mJ could produce chemical changes in proteins, phosphate, and carbonate in dentin.

Uso de fluorescência a laser no monitoramento de lesões de cáries incipientes: estudo in vivo / Use of laser fluorescence for monitoring incipient dental caries: an in vivo study

O objetivo deste estudo foi avaliar a performance do laser de diodo (DIAGNOdent, Kavo, Biberach, Alemanha) no monitoramento de lesões de cáries incipientes, não cavitadas, submetidas a fluorterapia. Foram selecionadas cinquenta e uma lesões de mancha branca diagnosticadas visualmente como ativas (aspecto rugoso e opaco) em superfícies lisas de dentes permanentes. Pacientes na faixa etária de 9 a 14 anos (n=19) foram submetidos a um programa de orientação de higiene bucal e bochechos de flúor diário (0,05 por cento) durante oito semanas. Neste intervalo, as lesões de mancha branca receberam cinco aplicações semanais de verniz fluoretado (Duraphat, Colgate). As leituras foram sempre realizadas após profilaxia e secagem na primeira (L1), quinta (L2) e nona (L3) semana do estudo a após 20 meses (L4) da leitura inicial. Os escores médios (DP) obtidos para L1, L2, L3 e L4 foram: 22,5 (15,5); 17,2 (13,9); 15,0 (13,7); 11,7 (10,8), respectivamente. O decréscimo nos escores foi significativo (p<0,05, teste t de Student pareado) para todos pares de semanas calculados exceto entre L2-L4 e L3-L4. Os dados sugerem que o DIAGNOdent pode ser útil para o monitoramento de lesões de cárie incipientes em superfícies lisas de dentes permanentes.

Effects of treatment for manipulation of teeth and Er:YAG laser irradiation on dentin: a Raman spectroscopy analysis.

OBJECTIVE: The main purpose of this study was to evaluate the utility of Raman spectroscopy analysis as a research tool to study the effects of Er:YAG laser etching on dentin mineral and organic components. A secondary aim was to study the effects of the decontamination process and the storage procedure on dentin components. BACKGROUND DATA: There are no spectroscopy reports relating the effects of Er:YAG laser irradiation as an alternative to acid etching and the manipulation process on the dentin structure. METHODS: Twelve non-carious human third molars were divided in two main groups: stored in thymol solution (group A, n = 6) or autoclaved (group B, n = 6). The specimens were either etched with 37% phosphoric acid (control subgroup) or irradiated with Er:YAG laser. Irradiated samples were divided into the following subgroups: I, II, and III (80 mJ, 3 Hz, 30 sec; 120 mJ, 3 Hz, 30 sec; and 180 mJ, 3 Hz, 30 sec, respectively). Samples were analyzed by Raman spectroscopy. RESULTS: The mineral and organic dentin contents were more affected in autoclaved teeth than in the specimens stored in thymol. Peak area reduction in group A specimens treated with phosphoric acid and pulse energy of 80 mJ were the most conservative surface treatments regarding changes in the peak area of organic and inorganic dentin components. CONCLUSION: The autoclaving process and pulse energies of 120 and 180 mJ produced greater reduction of organic and inorganic contents in dentin, associated with greater reduction in the areas of 968, 1077, 1460, and 1670 cm(1) Raman peaks.

Avaliação eletromiográfica de pacientes com DTM após a laserterapia / The electromyography evaluation in Temporomandibular joint disease patients after laser therapy

Este estudo avaliou a eficiência imediata da laserterapia de baixa potência em 13 pacientes portadores de dor e disfunção da articulação temporomandibular. Foram realizados exames clínicos para definir o lado de maior sintomatologia dolorosa e comprometimento da disfunção temporomandibular que foi tratado com aplicação do laser de diodo (Al-Ga-As), de comprimento de onda de 790 nm (infravermelho), irradiado em quatro pontos na disfunção da articulação temporomandibular com 1,5 J/cm²; um ponto na região do ouvido externo, com 2,5 J/cm²; em três pontos no músculo masseter, com 3 J/cm²; e três pontos no músculo temporal, com 3 J/cm². Os pacientes foram submetidos a uma avaliação subjetiva de dor. Os músculos masséter e temporal, de ambos os lados, foram avaliados eletromiográficamente antes da laserterapia, imediatamente a aplicação do laser, cinco minutos e vinte minutos após. Foram observadas reduções das atividades eletromiográficas medidas para todos os tempos, em ambos os músculos masseter e temporal, após a aplicação do laser. Conclusão: A laserterapia promoveu o relaxamento imediato dos músculos masseteres e temporais avaliados e conseqüente alívio na sintomatologia dolorosa.

Novo protocolo com LEDs verdes para o clareamento dental / A new protocol with green LEDs for tooth bleaching

Nos dias atuais vivenciamos uma crescente preocupação do ser humano com a estética e a saúde, o que faz com que um maior número de pacientes procure a Odontologia Estética. O clareamento dental é uma técnica não-invasiva que possibilita ao cirurgião dentista corresponder à expectativa destes pacientes em busca de dentes mais claros e sorrisos perfeitos. Este trabalho apresenta um novo protocolo desenvolvido para clareamento dental através da utilização da Light Emitting Diode verdes, descrevendo o preparo e manuseio do equipamento, a avaliação e preparo do paciente, a aplicação do agente clareador, o mecanismo de ativação do gel e os cuidados pós clareamento recomendados ao paciente. Esta técnica mostra-se eficaz e apresenta diversas vantagens em relação às outras alternativas disponíveis até o presente momento. O Light Emitting Diode verde possui o espectro de emissão e aproveitamento comparáveis ao laser de Argônio e apresentam aumento mínimo de temperatura. Como uma alternativa ao alto custo dos lasers, o Light Emitting Diode verde se apresenta como uma alternativa mais eficaz para a fotoativação do gel no processo de clareamento. Verifica-se também uma diminuição do tempo de trabalho, uma vez que o clareamento é realizado nas duas arcadas simultaneamente. A produção de resultados mais eficazes e menor sensibilidade, tornam esta técnica mais acessível para o uso na clínica odontológica.

Estudo do aquecimento gerado pelo laser Er: YAG na câmara pulpar de dentes submetidos ao processo de remoção dos tecidos dentais e resinas compostas / Study on heating generated by YAG Er: laser in the pulp chambers of the submitted to dental tissue and composite removal processes

O conhecimento e controle da energia térmica produzida pelo laser ER: YAG na irradiação dos tecidos dentais (esmalte e dentina) e resina composta e importante porque a polpa dental, como todo tecido biológico vivo, tem uma capacidade limitada de suportar estímulos térmicos. O objetivo deste estudo foi anlaisar a variação térmica gerada pelo laser de ER: YAg ( =2,94 µm) aplicado nas frequências de 3, 4 e 6 Hz durante o preparo cavitário Classe I a estrutura dental bem como na remoção de resina composta microhíbrida Z100® (3M). foram avaliados 30 dentes pré-molares superiores humanos do banco de dentes do Laboratório de Pesquisa em Endodontia da FORP-USP. A amostra foi dividida em 6 grupos de 5 dentes cada correspondentes às interações entre estrutura removida versus frequência de aplicação do laser com energia de 350mJ por pulso e energia total de 120J para o grupo de estrututa dental e 90J para o grupo de resina composta. Grupo 1, preparo de cavidade Classe I com laser de Er: YAg (4Hz, 343 impulsos, 113 segundos); Grupo 2, preparo de cavidade Classe I com laser de Er: YAG (6Hz, 343 impulsos, 81 segundos); Grupo 3, preparo de cavidade Classe I com laser de Er: YAG (6Hz, 343 impulsos, 58 segundos); Grupo 4: remoção de resina composta de preparo Classe I com laser de Er: YAG (3Hz, 258 impulsos, 85 segundos); Grupo 5, remoção de resina composta de preparo Classe I com laser de Er: YAG (4Hz, 258 impulsos, 67 segundos); Grupo 6, remoção de resina composta de preparo Classe I com laser de Er: YAg (5Hz, 258 impulsos, 42 segundos). O laser utilizado foi o KaVo® Key 2 (Biberach - Alemanha), = 2,94µ