Histomorphometric Analysis of the Healing Capacity of Low-Level Laser on Thermally Induced Tongue Ulcers for Gamma-Irradiated Rats.

Objective: This study aimed to assess the efficacy of low-level laser therapy (LLLT) for treating thermal tongue ulcers in gamma-irradiated rats. Background: Postradiotherapeutic trauma may cause cell death, tissue damage, organ dysfunction, and loss of hematological components. Materials and methods: Thermal ulcers were induced on the dorsal surfaces of tongues of gamma-irradiated rats (15 Gy). Rats were divided into three groups, group 1 received no treatment, group 2 was subjected to a single dose of diode laser 807 nm with energy density 4 J/cm2, and group 3 was subjected to the same dose of LLLT but fractionated into three sessions at days 1, 3, and 5 after ulcers induction. Ulcers were assessed clinically for their areas and healing percentage. Specimens were examined for the quality of ulcer closure and expression of IL-1ß and TGF-ß1. Results: Results revealed significant improvement of ulcer healing clinically and histologically in both treatment groups compared to control. Moreover, IL-1ß and TGF-ß1 expression in both treatment groups was high at the earlier stage of healing then declined by time to reach a normal level. However, untreated group showed higher expression of IL-1ß and TGF-ß1 compared to treatment groups. In addition, IL-1ß expression decreased by time but still of high level and TGF-ß1 expression increased then declined. Conclusions: We concluded that gamma radiation-impaired mucosal healing could be related to the over expression of IL-1ß and TGF-ß1. LLLT, whether one session or fractionated, could be an effective treatment for postradiotherapeutic ulcers. The healing power of LLLT might be due to modulation of IL-1ß and TGF-ß1. Clinical Trial Registration number is 25A122.

Evaluating the Effect of Low Power Diode Laser 806†nm on the Healing of Unilateral Cleft Lip Scar: An Open-Label Comparative Study.

OBJECTIVE: To investigate the effect of laser bio-modulation irradiation therapy on the scar after surgical correction of unilateral cleft lip. DESIGN: a comparative, open-label study. SETTING: we conducted the study in a university based tertiary hospital that recruited early wound healers of unilateral cleft lip correction. PATIENTS: Eighty patients were divided into two groups: In study's group, patients undergo laser bio-modulation irradiation (n = 60); in the control group, patients were followed-up without intervention (n = 20). INTERVENTION: In the study's group, patients underwent low-power diode Laser with wavelength of 806 nm and power of 100 mw. MAIN OUTCOME: The change in the scar of cleft lip patients, which was assessed by clinical examination and ultrasound. RESULTS: The median pigmentation score was significantly lower in the laser group (median = 1; IQR = 1-2) than the control group (median 2; IQR 1-3), with p-value of <0.001. Likewise, the median height score was significantly lower in the laser group (median = 1; IQR = 1-1) than the control group (median 1.5; IQR 1.5-2), with p-value of 0.001. The median pliability score was significantly lower in the laser group (median = 1; IQR = 1-1) than the control group (median 2.5; IQR 1-3), with p-value of <0.001. Finally, the median vascularity score was significantly lower in the laser group (median = 1; IQR = 1-1) than the control group (median 1.5; IQR 1-2), with p-value of <0.001. CONCLUSION: laser bio-modulation irradiation therapy demonstrates a potential efficacy in managing the hypertrophic scars after surgical repair of unilateral cleft lip.

Efficacy of diode laser and sonic agitation of Chlorhexidine and Silver-nanoparticles in infected root canals / Eficácia do laser de diodo e agitação sônica de clorexidina e nanopartículas de prata em canais radiculares infectados

Objective: To assess the efficacy of agitation of chlorohexidine (CHX) and Silver nanoparticles "AgNps" with 810nm diode laser or sonic endoactivator compared to side ­vented needle on infected root canals with Enterococcus "E" Faecalis biofilms. Material and Methods: Sixty-five extracted human premolars with single oval canals were instrumented by protaper system up to F3. Biofilms of E. faecalis were generated based on a previously established protocol. Two teeth were used to check the biofilm formation, then the remaining Teeth were randomly divided into three equal experimental groups according to agitation techniques used: group 1 (810 nm diode laser with 1 watt) , group 2 (sonic endoactivator) and group 3 (Side vented needle). Each group was further divided into three equal subgroups according to the irrigant solution into; subgroup A: chlorohexidine, subgroup B: silver nanoparticles and subgroup C: distilled water: Confocal laser scanning microscopy "CLSM" was used to assess bacterial viability. Data were analyzed by appropriate statistical analyses with P = 0.05. Results: Regarding the activation method, all groups had a significantly high percentage of dead bacteria (P < 0.05). However, Laser was significantly the highest and Endoactivator the least (P < = 0.001). Diode laser agitation of AgNps irrigant showed the highest reduction percentage of bacteria (78.1%) with a significant difference with both CHX and water irrigation, Conclusion: Under the condition of the present study; results reinforced that laser activation is a useful adjunct, 810 nm diode laser agitation of AgNps or chlorhexidine was more effective in disinfection of oval root canals than endoactivator and side vented needle techniques. (AU)

Objetivo: Avaliar a eficácia da agitação de clorohexidina (CHX) e nanopartículas de prata (AgNps) , com laser de diodo de 810 nm ou endoativador sônico, em comparação à agulha de ventilação lateral, em canais radiculares infectados com biofilmes de Enterococcus "E"; Faecalis. Material e Métodos: Sessenta e cinco pré-molares humanos com um único canal oval, extraídos, foram instrumentados pelo sistema protaper até F3. Os biofilmes de E. faecalis foram gerados com base em um protocolo previamente estabelecido. Foram utilizados dois dentes para verificar a formação do biofilme, e os dentes restantes foram divididos aleatoriamente em três grupos experimentais iguais, de acordo com as técnicas de agitação utilizadas: grupo 1 (laser de diodo 810 nm com 1 watt), grupo 2 (endoativador sônico) e grupo 3 (Agulha com ventilação lateral). Cada grupo foi dividido em três subgrupos iguais, de acordo com a solução irrigante; subgrupo A: clorohexidina, subgrupo B: nanopartículas de prata e subgrupo C: água destilada: A microscopia confocal de varredura a laser foi usada para avaliar a viabilidade bacteriana. Os dados foram analisados por análises estatísticas apropriadas com P = 0,05. Resultados: Em relação ao método de ativação, todos osgrupos apresentaram percentual significativamente alto de bactérias mortas (P < 0.05). No entanto, para o laser foi significativamente o mais alto e, para oendoativador, o menos alto (P < = 0.001). A agitação com laser de diodo doirrigante AgNps apresentou a maior porcentagem de redução de bactérias (78,1%), com diferença significativa tanto para irrigação com CHX quanto comágua. Conclusão: Sob as condições do presente estudo; os resultadosreforçaram que a ativação a laser é um complemento útil, a agitação por laserde diodo de 810 nm de AgNps ou clorexidina foi mais eficaz na desinfecção dos canais radiculares ovais do que as técnicas de endoativador e agulha com ventilação lateral. (AU)

Microhardness and Ultrastructure of Demineralized Gamma-Irradiated Human Enamel after Diode Laser (980 nm) and Fluoride Surface Treatment

Abstract Quality of life drastically diminished after radiotherapy due to radiation induced oral complications. Fluoride was found to be helpful in decreasing the incidence of radiation caries; however it has not led to elimination of dental caries. Thus, new techniques containing low fluoride concentration or not containing fluoride at all, as laser irradiation, have been studied to prevent the beginning or progression of caries. So the purpose of this study is to investigate the effect of laser surface treatment with or without fluoride on microhardness and ultrastructure of demineralized gamma irradiated enamel; Thirty enamel slabs were allocated into three groups (n=10): G slabs were subjected to gamma irradiation only; GL slabs were subjected to gamma irradiation followed by diode laser and GFL slabs were subjected to gamma irradiation followed by fluoride then diode laser. Slabs were then exposed to demineralizing solution for 72 hours. Examination of slabs was performed using vickers microhardness test and scanning electron microscope; The lowest microhardness was recorded in group G, while inGL and GFL groups it significantly increased. Scanning electron microscope revealed a pronounced loss of central prism core and retention of prism peripheries in group G. Confluence of prismatic and interprismatic structures in GL slabs and irregular rough surface with prismatic boundaries conservation in GFL slabs were detected. Applying laser improved the microhardness and counteracted the adverse effect of gamma radiation. Adding fluoride before laser irradiation had a marked effect on microhardness..

The effect of combining laser and nanohydroxy-apatite on the surface properties of enamel with initial defects.

BACKGROUND: The aim of this study was to evaluate the effect of combining fractional CO2 LASER and nanohydroxy apatite on surface microhardness and color of enamel with initial defects. MATERIAL AND METHODS: Two types of nano hydroxylapatite (nHAP) was prepared; Pure hydroxyapatite (nHA) and Fluoro hydroxyapatite (nFHA), Sixty extracted premolar teeth without visible caries or structural defects on enamel surface were used, immersed in 10 ml of a demineralizing solution for 2 weeks to create artificial white spot lesions, they were randomly allocated into two groups; Group 1: nHA, Group 2: nFHA, each group is then subdivided into 2 subgroups (A and B) where two different in vitroremineralization procedures have been performed, the first procedure utilizes a 10 wt% nHA aqueous slurries only, the second was first exposed to irradiation from a fractional CO2 laser then (nHAP) was applied. Microhardness and color were measured using a micro-Vickers hardness tester and spectrophotometer respectively. RESULTS: Laser treated teeth in both groups showed the highest mean hardness and lowest color difference where ΔE was less than 3.3 units, in both tests the pure type of nanohydroxyapatite gave better results than the nanofluroapatite type. CONCLUSIONS: Nano-hydroxyapatite has remarkable remineralizing effects on initial lesions of enamel, certainly higher when combined with laser application. Key words:CO2 LASER, Enamel remineralization, Nanohydroxy apatite.

Herpes virus reactivation by low-intensity diode and CO2 lasers.

BACKGROUND: The herpes virus enters into latency after symptomatic or asymptomatic herpetic infection. During latency, the virus has no impact on infected cells. However, internal or external stimuli, including certain lasers, can induce virus reactivation. OBJECTIVE: The aim was to study the reactivation power of the low-intensity diode and CO(2) lasers on the latent herpes virus. MATERIALS AND METHODS: The bovine herpesvirus 1 (BHV-1) was inoculated in either the nasal cavity or the lacrimal film of an animal model. Once the virus entered into latency, the trigeminal ganglia of animals were exposed to either a low-intensity diode or CO(2) laser. The reactivation of the virus was then explored by PCR, RT-PCR, and dot-blot hybridization on nasal or lacrimal swabs. The accuracy, sensitivity, and specificity of the aforementioned techniques were compared. RESULTS: The low-intensity diode laser reactivated the herpes virus less than the CO(2) laser. The nasally inoculated virus was more liable for reactivation by both lasers. PCR was considered as the standard method for the detection of the reactivated virus. CONCLUSIONS: Low-intensity diode and CO(2) lasers can induce herpes virus reactivation, with the diode laser less likely to reactivate the virus than the CO(2) laser.