João Batista Blessmann Weber

Analysis of the Systemic Effect of Red and Infrared Laser Therapy on Wound Repair

OBJECTIVE To evaluate, using histological analysis, the systemic action and repair process of wounds produced on the back of rats and treated with red, infrared, or both lasers applied directly or indirectly to the wounds. BACKGROUND DATA Skin tissue repair and wound healing are complex processes that involve a series of dynamic events. Many benefits are associated with biomodulation using laser therapy. METHODS Thirty-six male Wistar rats were divided into four groups: control (without laser), red laser (aluminium gallium indium phosphide (AlGaInP); lambda=685 nm; phi=0.0314 cm2; CW; P=30 mW; D=20 J, time of irradiation=667 sec), infrared laser (gallium-aluminum-arsenide (GaAlAs): lambda=830 nm; phi=0.0314 cm2; CW; P=50 mW; D=20 J, time of irradiation=401 sec), and both lasers (infrared laser: GaAlAs; lambda=830 nm; phi=0.0314 cm2; CW; P=50 mW; D=10 J, time of irradiation=201 sec+red laser: AlGaInP; lambda=685 nm; phi=0.0314 cm2; CW; P=30 mW; D=10 J, time of irradiation=334 sec; total dose=20 J). Three subgroups were formed according to observation time points. Three wounds were produced on the back of each animal. Only the wound closest to the head was irradiated in the experimental groups. For the evaluation of skin reaction and wound healing, three animals of each group were killed at 3, 5, and 7 days postoperatively. The irradiation protocol established 48-hour intervals between applications, with the first application immediately after the surgical procedure. RESULTS In the red and infrared laser group, healing was more advanced in the wound located furthest from the point of laser application. The most effective healing of a proximal wound was verified in the control group on the 7th postoperative day. CONCLUSION The combined application of red and infrared lasers resulted in the most evident systemic effect on the repair of skin wounds produced in rats.

Influence of Low-Level Laser Therapy on the Rate of Orthodontic Movement: A Literature Review

OBJECTIVE The purpose of this study was to review low-level laser therapy (LLLT) protocols that have been used to date, and to indicate which parameters appear to be most effective to guide future research. BACKGROUND DATA Studies assessing the influence of LLLT on the rate of orthodontic tooth movement have produced controversial results as a result of methodological differences. METHODS The MEDLINE(®) database (1975-2012) and the Cochrane library (subject 8) were reviewed. Clinical studies and animal experiments written in English and focusing on the effects of LLLT on the rate of orthodontic movement were browsed. Article selection was conducted by one reviewer and checked by a second investigator. RESULTS A total of 109 articles were identified, of which 14 were selected for detailed analysis. Diode laser was used in all studies with different energies, frequencies, and doses. In animal studies, the most common and effective energy input was 54 J per session daily; in humans, it was 2 J per session on the first days of each month, with 72-96 h intervals. Orthodontic force also influenced orthodontic movement. A force of 10 g/force seems to be indicated for moving molars in rats, versus 150 g for canines in humans. CONCLUSIONS Most authors report positive effects of the use of LLLT on speed increase of orthodontic tooth movement when compared with control or placebo groups. Diode laser, especially gallium aluminum arsenide, used continuously and in direct contact with the irradiated areas, was the most frequent protocol. Further studies are warranted to determine the best protocols with regard to energy, dose, and intervention schedule.

CO2, Er: YAG and Nd:YAG lasers in endodontic surgery

Objectives: CO2, Er:YAG and Nd:YAG lasers have been used in endodontic surgery. This in vitro study evaluated 1% Rhodamine B dye penetration using computer-assisted morphometry (ImageTool Software®) of 108 endodontically treated human permanent canines. Material and methods: Teeth were divided into 9 groups according to the technique used: A: 90-degree apicoectomy with bur, root-end cavity preparation with ultrasound and filled with MTA; B: 90-degree apicoectomy with bur, root-end cavity prepared with ultrasound and filled with MTA, and treatment of apical surface with CO2 laser (1 W, CW/CW); C: 90-degree apicoectomy with bur, and treatment of apical surface with Nd:YAG laser (150 mJ, 10 Hz); D: 90-degree apicoectomy with bur, and treatment of apical surface with CO2 laser (1 W, CW/CW); E: apicoectomy with Er:YAG laser (400 mJ, 10 Hz), root-end cavity prepared with ultrasound and filled with MTA; F: apicoectomy with Er:YAG laser (400 mJ, 10 Hz) and treatment of apical surface with Nd:YAG laser (150 mJ, 10Hz); G: apicoectomy with CO2 laser (5W, CW/SP), root-end cavity prepared with ultrasound and filled with MTA; H: irradiation of apical end with CO2 laser (1 W, CW/CW); I: irradiation of apical end with Nd:YAG laser (150 mJ, 10 Hz). Results: Dye penetration was found in all specimens at different rates, the lowest penetration occurring in groups C (16.20%), B (17.24%) and F (17.84%). Conclusions: Groups B, C and F represent the best technical sequences to perform endodontic surgery.

Comparação dos valores normativos e do dimorfismo sexual através das análises cefalométricas computadorizadas de Ricketts e Mcnamara em perfis esteticamente agradáveis

A presente pesquisa tem por objetivo estabelecer valores normativos, avaliar o dimorfismo sexual entre grandezas cefalometricas e correlacionar medias para a avaliacao de compensacoes biologicas que atuem na morfologia do perfil facial de tecidos moles, atraves das analises cefalometricas computadorizadas de Ricketts e McNamara. A amostragem foi composta por 40 telerradiografias laterais, de individuos com perfis esteticamente agradaveis. As radiografias foram analisadas atraves do programa Radiocef 2.0® nos metodos cefalometricos propostos, e posteriormente foram empregados o teste “t” de Student e o Coeficiente de Correlacao de Pearson. Nos homens, o Comprimento Anterior do Crânio, Comprimento do Labio Superior, Comprimentos Efetivos de Maxila e Mandibula, Altura Facial Inferior e Diâmetro Inferior da Faringe foram significativamente mais elevados. Nas mulheres, as medias mais elevadas foram para a Extrusao do Incisivo Inferior e Posicao Labial Inferior. A amostra masculina exibiu uma menor Altura Facial Inferior que a media dos valores padrao, mediante afericao linear, em razao do menor Comprimento Efetivo da Mandibula neste grupo; a mesma correlacao nao foi significativa para valores angulares. A Protrusao Labial Inferior esteve diretamente relacionada a diferente posicao espacial dos incisivos superiores e inferiores em ambas as amostras, na sua relacao com os tecidos moles e respectivas bases osseas, permitindo uma configuracao harmonica e diferenciada entre os generos.

Avaliação da ancoragem de implantes dentários irradiados com laser GaAlAs (830 nm)

O objetivo desta pesquisa foi avaliar, atraves do uso de um torquimetro digital, se implantes de titânio, instalados com liberdade rotaciona em tibias de coelhos e irradiados com laser de Arseneto de Galio e Aluminio, na dose de 86 J/cm2, com comprimento de onda de 830 nm, potencia de 12 mW e tempo de aplicacao de 51 segundos, apresentam um valor de torque de remocao estatisticamente maior que os valores obtidos nos grupos nao irradiados (grupo controle). Para tanto, trabalhou-se com trinta coelhos, da raca Nova Zelândia, machos, os quais foram divididos em dois grupos, Laser e Controle, e subdivididos de acordo com o dia de sua morte. Os grupos L1 e C1, L2 e C2, L3 e C3 foram mortos 15, 30 e 45 dias apos a insercao do implante, respectivamente. Um torquimetro digital mensurou o torque necessario para o afrouxamento do implante, rompendo sua uniao com o osso. Os resultados foram, entao, submetidos ao Teste “t” de Student e ao Teste ANOVA, a fim de validar esses achados. Observou-se, para um p=0,05, um aumento nos valores dos torques de remocao dos implantes irradiados com laser e controle (L1 e L2), tanto aos quinze quanto aos trinta dias apos as cirurgias, em relacao aos respectivos grupos controle (C1 e C2). Aos 45 dias, nao mais foi observada diferenca estatisticamente significante entre os valores encontrados nos grupos laser e controle (L1 e C1). Concluiu-se, nesse modelo animal e com o protocolo de irradiacao utilizado neste estudo, que o laser, por ser a unica variavel entre os grupos, foi responsavel pelo aumento do embricamento do implante ao osso, no mes inicial e mais critico da osseointegracao.