Low-level laser therapy (LLLT) improves alveolar bone healing in rats.

The main objective of the present study was to evaluate the effect of low-level laser therapy (LLLT) in enhancing bone healing in irradiated alveolus post-tooth extraction. Sixty male Wistar rats (180 ± 10 g) were used in the present study. The left maxillary first molars were extracted, and the alveolar region was irradiated by diode laser device (GaAlAs) immediately after extraction and for more 3-day daily applications. The animals were randomly assigned into two groups: control group (n = 30, with left maxillary molar extraction-CG) and experimental group (n = 30, with tooth extraction and low-level laser therapy applied to the dental alveolus for 42 s-EG). These groups were divided into subgroups (five rats per subgroup) according to the observation time point-1, 2, 3, 5, 7, and 10 days-post-tooth extraction. The maxillary bone was separated, and the specimens were stained with hematoxylin and eosin, Masson's trichrome, and picrosirius red and immunohistochemistry for RUNX-2. Parametric and nonparametric tests were used with a significance level of 5%. LLLT accelerated bone healing with mature collagen fiber bundles and early new bone formation. Histomorphometric analysis revealed an increase of osteoblast (RUNX-2) and osteoclast (TRAP) activity and in the area percentage of cancellous bone in the lased alveolus compared to the control group. This increase was statistically significant (p < 0.05). Application of LLLT with a GaAlAs diode laser device enhanced bone healing and mineralization on alveolar region.

Local anesthetic improves individuals affected with herpes simplex type 1 labialis.

Infections caused by the herpes simplex virus 1 (HSV-1), commonly called herpes simplex labialis (HSL), are a public health problem, reaching around 40% of the world's population. Thus, the search for effective therapeutic alternatives in the control of the limitations caused by this virus during the stages of evolution of the disease, is necessary, since they have a direct impact on the quality of life of the patients. The aim of the present study was to evaluate the efficacy of the in situ film precursor semisolid composition in the treatment of herpes simplex lesions in human HSV-1. Ninety-eight (n = 98) patients with HSV-1 were used for this study. The initial exclusion criteria left 81 patients to be considered in the present study. Three applications were performed, the first at time zero (T0) and the other two at 8 and 16 hours, after initial application (T8 and T16). Photographs were taken in the first appointment and 24 and 72 hours after the last application. After the three periods, each patient received a total amount of 90 mg of anesthetic and the prognosis of the patients was followed for 6 months and 1 year after the application. Frequency analysis showed that 40.3% of patients had remission of symptoms 24 hours after the last application. For the present study, the film presented a positive therapeutic potential and an esthetic benefit that is absent in the current products (ointments and gels). The invent presents dosage convenience (only three applications in a 24-hour period) and a low production cost, with a much shorter healing time than that reported using topical antiretrovirals.

Effectiveness of rhBMP-2 association to autogenous, allogeneic, and heterologous bone grafts.

Proteins with osteoinductive potential, especially recombinant human bone morphogenetic protein (rhBMP)-2, have large effects on cell growth and their differentiation. The aim of this study was to assess repair of bone defects in rat calvaria with different types of grafts associated with rhBMP-2, through immunohistochemistry and micro computed tomography (CT) analyses. A total of 35 male Wistar rats were selected, each weighing ~250 g, with a waiting period of 6 weeks from the creation of the defect to the sacrifice, and divided into five groups (n = 7): autograft plus 5 µg rhBMP-2 (AuG/BMP-2); allograft plus 5 µg rhBMP-2 (AlG/BMP-2); xenograft (heterologous) plus 5 µg rhBMP-2 (XeG/BMP-2); 5 µg rhBMP-2 (BMP-2) and the control group (n = 7). The micro CT reveal that all groups associating different bone grafts with BMP-2 showed increased bone formation compared to the control. The immunostaining show that osteocalcin and bone sialoprotein were higher in groups with BMP-2 than control group; BMP was high expressed in AuG/BMP-2, AlG/BMP-2, and BMP-2; vascular endothelial growth factor (VEGF) was more expressed in groups with BMP-2; VEGF-R2 was low to moderate in AuG/BMP-2, XeG/BMP-2, and BMP-2, predominantly moderate in AlG/BMP-2 and low in the control; CD-31 was predominantly moderate in AuG/BMP-2, AlG/BMP-2, and XeG/BMP-2, low to moderate in BMP-2 and low in the control. The results revealed that rhBMP-2 improved bone repair when administered alone, or when associated with different bone grafts.

Tobacco influence in heavy metals levels in head and neck cancer cases.

Heavy metals intoxication is known to be risk factors for various diseases, including cancer. These metals may be presented in food and soil as well as in leaf and tobacco smoke. The aim of this study was to correlate the exposure to heavy metals stemming from tobacco and head and neck squamous cell carcinoma carcinogenesis. Analysis of lead, copper, manganese, arsenic, chromium, and cadmium by atomic absorption spectrophotometry was performed in whole blood samples from 91 patients: 68 smokers with oral cavity, pharynx, or laryngeal cancer; 8 non-smokers with oral or larynx cancer; and 15 non-cancer smokers with tobacco-related diseases (control group). No differences were found in metals quantifications, except a significant difference was observed (p = 0.0223) with higher mean in copper levels for non-smokers with cancer. The present study concluded, for the groups evaluated, it was not possible to prove the relationship between the studied metals in the development of the neoplasm. On the other hand, the results of copper demonstrated a correlation with smokers with cancer and lower levels of circulating copper.

Lead line in rodents: an old sign of lead intoxication turned into a new method for environmental surveillance.

The "lead line" was described by Henry Burton in 1840. Rodents are used as sentinels to monitor environmental pollution, but their teeth have not been used to determine lead. To determine whether lead deposits can be observed in the teeth of lead-exposed animals, since the gingival deposits known as "lead line" would likely have a correlate in the calcified tissue to which the gums are opposed during life. Male Wistar rats were exposed to lead in the drinking water (30 mg/L) since birth until 60 days-old. Molars and the incisors of each hemimandible were analyzed by scanning electron microscopy (SEM) on regular and backscattered electrons (BSE) mode. Elements were determined using electron dispersive spectroscopy (EDS). Clean cervical margins were observed on control teeth, as opposed to the findings of extensive deposits on lead-exposed animals, even in hemimandibles that had been exhumed after being buried for 90 days. BSE/EDS indicated that those deposits were an exogenous material compatible with lead sulfite. Presence of calcium, phosphorus, magnesium, carbon, lead, and oxygen is presented. Lead-exposed animals presented marked root resorption. The lead deposits characterized here for the first time show that the "lead line" seen in gums has a calcified tissue counterpart, that is detectable post-mortem even in animals exposed to a low dose of lead. This is likely a good method to detect undue lead exposure and will likely have wide application for pollution surveillance using sentinels.

Reduced bone and body mass in young male rats exposed to lead.

The aim of this study was to see whether there would be differences in whole blood versus tibia lead concentrations over time in growing rats prenatally. Lead was given in the drinking water at 30 mg/L from the time the dams were pregnant until offspring was 28- or 60-day-old. Concentrations of lead were measured in whole blood and in tibia after 28 (28D) and 60 days (60D) in control (C) and in lead-exposed animals (Pb). Lead measurements were made by GF-AAS. There was no significant difference (P > 0.05) in the concentration of whole blood lead between Pb-28D (8.0 ± 1.1 µg/dL) and Pb-60D (7.2 ± 0.89 µg/dL), while both significantly varied (P < 0.01) from controls (0.2 µg/dL). Bone lead concentrations significantly varied between the Pb-28D (8.02 ± 1.12 µg/g) and the Pb-60D (43.3 ± 13.26 µg/g) lead-exposed groups (P < 0.01), while those exposed groups were also significantly higher (P < 0.0001) than the 28D and 60D control groups (Pb < 1 µg/g). The Pb-60D group showed a 25% decrease in tibia mass as compared to the respective control. The five times higher amount of lead found in the bone of older animals (Pb-60D versus Pb-28D), which reinforces the importance of using bone lead as an exposure biomarker.