Ameliorating orthodontic relapse using laser bio-stimulation and mesenchymal stem cells in rats.

BACKGROUND: Orthodontic relapse is a frequent problem that many patients experience. Although orthodontic therapy has advanced, recurrence rates can still reach 90%. We undertook a study to look at the possibilities of laser bio-stimulation and stem cells because they have showed promising outcomes in lowering recurrence rates. OBJECTIVES: Our objective was to analyze the effects of Low-level laser therapy (LLLT) and Mesenchymal stem cells (MSC) alone and collectively on the rate of orthodontic relapse in rats radiographically and histologically. METHODS: Rat maxillary central incisors were moved distally for two weeks. One week later, the incisors were retained. Animals (n = 40) were split into four groups. Control group (C); laser treatment Group (L), Bone marrow mesenchymal stem cells Group (BMSCs) and combination of Stem cells and laser-irradiation group (BMSCs-L). Removed retainer permitted relapse. Before stem cell application or laser irradiation, each animal underwent two CBCT scans. Rat maxillae were stained with Hx&E, Masson trichrome, and tartrate-resistant acid phosphatase antibody for histology, histochemistry, and immunohistochemistry. RESULTS AND CONCLUSIONS: LLLT could reduce the relapse tendency, as shown by increased bone density and enhanced remodeling of hetero-formed periodontal ligament (PDL). Furthermore, the transfer of BMMSCs on the pressure side had positive effects on PDL remodeling and decreased, but did not inhibit, the relapse rate. Finally, the synergistic effects of the application of LLLT and BMMSC were better than the control but still moderate and long-lasting. CLINICAL SIGNIFICANCE: Based on the improved relapse rate as proven in the present study, the Application of both LLLT and stem cells can be adopted to reduce the relapse tendency either lonely or collectively.

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.

Influence of Nanocurcumin and Photodynamic Therapy Using Nanocurcumin in Treatment of Rat Tongue Oral Squamous Cell Carcinoma Through Histological Examination and Gene Expression of BCL2 and Caspase-3.

Background: Oral squamous cell carcinoma (OSCC) is the sixth most common mouth cancer in the world. The aim of the present study is comparing the effects of using Nanocurcumin, and photodynamic therapy (PDT), alone or together in treatment of OSCC in rats. Methods: Forty Wister male rats were divided into Control (group 1), 650 nm diode Laser only (group 2), Nanocurcumin alone (group 3), and PDT with a combination of laser with Nanocurcumin (group 4). Then, OSCC in the tongue induced by dimethylbenz anthracene (DMBA). The treatments were evaluated clinically, histopathologically, and immunohistochemically through BCL2 and Caspase-3 genes expression. Results: Positive control with OSCC displayed significant weight loss, while PDT group gained more than nanocurcumin treated groups as well as laser groups comparing with control positive group. The histological examination of the tongue in PDT group showed improvement. In laser group, there were partial loss of surface epithelium with various ulcers and dysplasia and partial improvement by this type of treatment. The tongue in the positive control group showed ulcer in the dorsum surface with inflammatory cells, hyperplasia of the mucosa membrane around the ulcer (acanthosis) with increase of dentition, vacuolar degeneration of prickle cell layer and increase mitotic activity of basal cell layer together with dermal proliferation. Conclusion: Under the condition of the present study, PDT using nanocurcumin photosensitizer was effective in the treatment of OSCC regarding clinical, histological and gene expression of BCL2 and Caspase-3.

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)

Enhancement of Healing of Periodontal Intrabony Defects Using 810 nm Diode Laser and Different Advanced Treatment Modalities: A Blind Experimental Study.

BACKGROUND: Low-level laser therapy (LLLT) in the early stage of bone healing was demonstrated as a positive local biostimulative effect. It was also shown that platelet-rich fibrin (PRF) and nanohydroxyapatite alloplast (NanoHA) are effective in treating periodontal intrabony defects. AIM: The study aimed to evaluate the combined effects of LLLT (810 nm), PRF and NanoHA on induced intrabony periodontal defects healing. MATERIAL AND METHODS: The study was conducted on 16 defects in 8 adult male rabbits (n = 16) divided into 4 groups; Control non-treated group (C), laser irradiated control group (CL), PRF+NanoHA graft (NanoHA-Graft+PRF) treated group and laser irradiated and treated group (NanoHA-Graft+PRF+L). CT radiography was made at baseline, 15 and 30 days later. The defects were induced in the form of one osseous wall defects of 10 mm height, 4 mm depth between the 1st and the 2nd molars using a tapered fissure drill coupled to a high-speed motor. Statistical analysis was done using ANOVA. RESULTS: (NanoHA-Graft+PRF+L) group significantly produced bone density higher than C, CL and NanoHA-G+PRF alone. CONCLUSION: The combination of LLLT+PRF+NanoHA as a treatment modality induced the best results in bone formation in the bone defect more than LLLT alone or PRF+NanoHA alone.

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..

Assessment of Photodynamic Therapy and Nanoparticles Effects on Caries Models.

AIM: To assess the antibacterial competence of 650 nm diode laser, Methylene Blue (MB) and Silver Nano-Particles (Ag NPs) on Streptococcus mutans in biofilm-induced caries models. MATERIAL AND METHODS: One hundred eighty specimens were prepared and equally divided into 6 groups. One group was untreated (control), and the others were subjected to either MB, laser, Ag NPs, the combination of MB and Laser or MB, laser and Ag NPs. RESULTS: Comparison of the log10 mean Colony Forming Units per millilitre (CFU/ml) values of each of the treated 5 groups and the control group was found statistically significant (P-value < 0.05). The combination of MB, laser and Ag NPs recorded the greatest reduction (95.28%). MB alone represented the least capable (74.09%). The efficiency differences among the Ag NPs treated group; the Laser treated group and the combined MB/Laser treated group were found statistically insignificant. CONCLUSION: The combination of MB, 650 nm diode laser and Ag NPs may be among the highly effective modern antimicrobial therapeutics in dentistry.

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.

Assessment of the effect of low-energy diode laser irradiation on gamma irradiated rats' mandibles.

OBJECTIVE: The purpose of the present study was to evaluate the biostimulative and regenerative effects of low intensity laser irradiation (LILT) (applied before or after initiation of radiotherapy) on gamma irradiated rats' jaw bones. METHODS: Forty eight male Albino rats were equally divided into two groups: group 1, in which the left side of the mandible was subjected to three successive sessions of laser (LILT) prior to whole body gamma radiation (2Gy/3 fractions/week) and group 2, received whole body gamma radiation (2Gy/3 fractions/week) prior to three successive sessions of laser applied to left side. The right side of both groups was used as gamma irradiated non-lased control group. Each group was then subdivided into four equal subgroups (a, b, c, d) according to the time of scarification (3, 7, 14, 21 days respectively). Specimens were subjected to histological, histomorphometric and scanning electron microscopic examinations. RESULTS: Thin irregular bone trabeculae and widened marrow spaces were identified in the control group. The lased sides of groups 1 and 2 demonstrated regular, thick and continuous bone trabeculae. Ultrastructurally, collagen fibres of the control group appeared irregularly arranged and more spaced compared to groups 1 and 2. Normal-sized osteocytic lacunae were seen in the lased groups, as compared to the wide lacunar spaces noted in the control group. Histomorphometric analysis showed a significant increase in the area of bone trabeculae, as well as the width of compact bone, for the lased groups. CONCLUSIONS: LILT seemed to attenuate the radiation-related damage in alveolar bones.

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.

Using pulsed dual-wavelength 595 and 1064 nm is more effective in the management of hemangiomas.

OBJECTIVE: To evaluate the efficacy of application of dual long-pulsed dye/Nd:YAG lasers in the management of skin and mucous membrane infantile hemangiomas. BACKGROUND: Management of hemangiomas may be a challenge. Different laser systems have been reported to be of significant help for such cases with variable results. PATIENTS AND METHODS: In this study, the authors present a unique sequential laser system, which delivers pulsed dye laser (PDL) 595 nm followed by Nd:YAG 1064 nm, which they have found to be superior and more effective than other reported techniques. Twenty-five cases of infantile hemangiomas in the skin and mucous membrane in the head and neck region were selected to be enrolled in this study. Assessment for progress was achieved clinically. RESULTS: The authors achieved excellent results in eighteen patients (72%) out of the 25 treated patients, with no recurrence after six-month follow-up. Laser application from skin and mucous membrane sides (sandwich technique) decreased number of sessions. CONCLUSION: The sequential application of 595 nm PDL followed by 1064 nm Nd:YAG laser can be considered a superior method for management of infantile hemangiomas, especially in the head and neck region, due to its excellent cosmetic results with fewer treatment sessions.

Excision biopsy of tongue lesions by diode laser.

OBJECTIVE: The aim of this study was to evaluate the diode laser in excision biopsy of superficial proliferative tongue lesions under local anesthesia. BACKGROUND DATA: Most mobile tongue lesions present as surface projections and have similar clinical features. They are usually excised for diagnostic purposes using conventional surgery or electrosurgery. The diode laser has proven itself useful in different oral surgeries. METHODS: We report the results of a prospective pilot study where contact diode laser was used in excision biopsy of six mobile tongue lesions. All excised tissues were pathologically examined. To assess post-operative pain, patients were asked to correlate it to an 11-point Visual Analogue Scale (VAS); patients were also asked to assess their impression of alteration in tongue size on a 4-point scale. Healing, functional results, and recurrence rate were assessed. RESULTS: All interventions were uneventful and done at the same out-patient setting. All lesions were benign. Healing occurred by secondary intention in the six cases with no residual ulceration. Postoperative pain was mild in four cases, while two cases suffered from moderate pain. Post-operative impression of tongue swelling occurred in all cases. The mild impression disappeared by the end of the first week and the moderate one by the end of the second week. No recurrence was observed over a mean follow-up period of 15 months. CONCLUSION: The diode 980-nm laser is optimal for excision biopsy of superficial and benign proliferative lesions of the mobile tongue.