Oxidative damage of canine erythrocytes after treatment with non-steroidal anti-inflammatory drugs.

OBJECTIVE: To investigate oxidative erythrocyte damage in dogs treated with different non-steroidal anti-inflammatory drugs. MATERIAL AND METHODS: Case-controlled prospective observational study using blood obtained from dogs presenting for lameness examinations or standard surgical procedures to a private referral clinic. Sampling was performed from April 2018 to July 2019. Groups comprised dogs receiving either metamizole (dipyrone) (22 dogs), carprofen (20 dogs) or meloxicam (20 dogs) for a minimum of 10 days. Dogs with gastrointestinal hemorrhage were excluded from the study. A complete hematological, as well as a basic biochemical profile were performed in every dog. Pappenheim stained blood smears were evaluated for eccentrocytes and brilliant cresyl blue stained smears for Heinz bodies. EDTA blood was frozen at -80°C immediately after sampling for measurement of superoxide dismutase and gluthathione peroxidase activity at an external laboratory. Hemoglobin concentration, superoxide dismutase and gluthathione peroxidase activities, reticulocyte count, eccentrocyte and Heinz body numbers were determined prospectively as key parameters for further statistical assessment with Kruskal-Wallis test and Dunn's multiple comparisons test. RESULTS: Dogs receiving metamizole showed a significant increase in eccentrocyte (median 14.5/500 cells vs. 0/500 cells in the other groups, p < 0.0001) and reticulocyte number (median 191.4 × 109/l vs. 31.6-37.9 × 109/l, p < 0.0001) and a significant decrease in hemoglobin concentration (median 8.4 mmol/l vs. 10.1-10.5 mmol/l, p < 0.0003). No significant difference in superoxide dismutase and gluthathione peroxidase activities was observed between dogs receiving metamizole and the other groups. Heinz bodies were not found in any of the dogs. CONCLUSION: Treatment with metamizole for 10 or more days resulted in decreased hemoglobin concentration, eccentrocytosis and reticulocytosis in dogs in this study. This might be a sign of increased oxidative damage caused by this drug. CLINICAL SIGNIFICANCE: Prolonged metamizole therapy should be evaluated critically in patients already affected by severe illness or underlying anaemia.

Transcriptional activity of vitamin D receptor in human periodontal ligament cells is diminished under inflammatory conditions.

BACKGROUND: Although vitamin D3 deficiency is considered as a risk factor for periodontitis, supplementation during periodontal treatment has not been shown to be beneficial to date. Human periodontal ligament cells (hPDLCs) are regulated by vitamin D3 and play a fundamental role in periodontal tissue homeostasis and inflammatory response in periodontitis. The aim of this study is to investigate possible alterations of the vitamin D3 activity in hPDLCs under inflammatory conditions. METHODS: Cells isolated from six different donors were treated with either 1,25(OH)2 D3 (0 to 10 nM) or 25(OH)D3 (0 to 100 nM) in the presence and absence of ultrapure or standard Porphyromonas gingivalis lipopolysaccharide (PgLPS), Pam3CSK4, or interferon-γ for 48 hours. Additionally, nuclear factor (NF)-κB inhibition was performed with BAY 11-7082. The bioactivity of vitamin D in hPDLCs was assessed based on the gene expression levels of vitamin D receptor (VDR)-regulated genes osteocalcin and osteopontin. Additionally, VDR and CYP27B1 expression levels were measured. RESULTS: The vitamin D3 -induced increase of osteocalcin and osteopontin expression was significantly decreased in the presence of standard PgLPS and Pam3CSK4, which was not observed by ultrapure PgLPS. Interferon-y had diverse effects on the response of hPDLCs to vitamin D3 metabolites. NF-kB inhibition abolished the effects of standard PgLPS and Pam3CSK4. Standard PgLPS and Pam3CSK4 increased VDR expression in the presence of vitamin D3 . CYP27B1 expression was not affected by vitamin D3 and inflammatory conditions. CONCLUSIONS: This study indicates that the transcriptional activity of VDR is diminished under inflammatory conditions, which might mitigate the effectiveness of vitamin D3 supplementation during periodontal treatment.

Temperature Development on the External Root Surface During Laser-Assisted Endodontic Treatment Applying a Microchopped Mode of a 980 nm Diode Laser.

OBJECTIVE: The aim of this article was to investigate the temperature increase of the external root surface during laser-assisted endodontic treatment using a diode laser (980 nm) in a microchopped mode. METHODS: Ten freshly extracted, human maxillary incisors with mature apices were collected, prepared to size F4 at working length (ProTaper; Dentsply Maillefer, Ballaigues, Switzerland), mounted to a holder, and irradiated (using spiral movements in coronal direction) with a diode laser (GENTLEray 980 Classic Plus; KaVo, Biberach, Germany) with a 200 µm fiber in four different treatment groups: Group 1 (control group) was irradiated in six cycles of 5-sec irradiation/20-sec pause with 2.5 W in the pulse mode. Groups 2 to 4 were irradiated at six cycles of 5-sec irradiation/20-sec pause in the microchopped mode (Group 2-1.6 W; Group 3-2.0 W; Group 4-2.5 W). The applied mode was 25 ms on/25 ms off. Within the on period, the laser delivered an intermittent sequence of energy complexes and the maximum output was equal to the nominated output of the device (12 W). Canals were kept moist by sterile saline irrigation in between irradiations, and temperature changes were continuously measured using a thermal imaging camera. Recordings were analyzed by a mixed model (analysis of variance [ANOVA] for repeated measurements). RESULTS: The highest mean of temperature rise, 1.94°C ± 1.07°C, was measured in Group 4, followed by Group 3 (1.74°C ± 1.22°C) and Group 2 (1.58°C ± 1.18°C). The lowest increase occurred in Group 1 (1.06°C ± 1.20°C). There was a significant difference (p = 0.041) between the groups. Significant differences were found between Groups 1 and 4 (p = 0.007) and 1 and 2 (p = 0.035). In addition, a marginally significant difference between Groups 1 and 2 (p = 0.052) was noted. There was no significant difference between Groups 2, 3, and 4. Despite the low mean values reported, the highest temperature increase (+5.7°C) was measured in one of the specimens of treatment Group 2 at the middle third. CONCLUSIONS: Under the conditions used and within the limitations of the study, the microchopped diode laser irradiation is a safe possible treatment option in laser-assisted endodontic treatment, concerning the temperature elevation on the external root surface.

The effects of CO2 laser with or without nanohydroxyapatite paste in the occlusion of dentinal tubules.

The aim of this study was to evaluate a new treatment modality for the occlusion of dentinal tubules (DTs) via the combination of 10.6 µm carbon dioxide (CO2) laser and nanoparticle hydroxyapatite paste (n-HAp). Forty-six sound human molars were used in the current experiment. Ten of the molars were used to assess the temperature elevation during lasing. Thirty were evaluated for dentinal permeability test, subdivided into 3 groups: the control group (C), laser only (L-), and laser plus n-HAp (L+). Six samples, two per group, were used for surface and cross section morphology, evaluated through scanning electron microscope (SEM). The temperature measurement results showed that the maximum temperature increase was 3.2 °C. Morphologically groups (L-) and (L+) presented narrower DTs, and almost a complete occlusion of the dentinal tubules for group (L+) was found. The Kruskal-Wallis nonparametric test for permeability test data showed statistical differences between the groups (P < 0.05). For intergroup comparison all groups were statistically different from each other, with group (L+) showing significant less dye penetration than the control group. We concluded that CO2 laser in moderate power density combined with n-HAp seems to be a good treatment modality for reducing the permeability of dentin.

The influence of different power settings of Nd:YAG laser irradiation, bioglass and combination to the occlusion of dentinal tubules.

OBJECTIVE: The purpose of this study was to investigate the influence of bioglass, Nd:YAG laser irradiation and their combination on dentinal tubuli occlusion as a potential dentinal hypersensitivity treatment for cervical dentinal hypersensitivity (CDH). BACKGROUND DATA: CDH affects 8-30% of adults and nearly 85% of perio-treated patients. Various treatment schemes have been applied for treating CDH, among them being fluoride application, laser irradiation, and, recently, bioglass (NovaMin(®)). In this in vitro study, we evaluated the efficacy of NovaMin(®) paste (NM) (Denshield, Sultan, USA), Nd:YAG laser irradiation (L) at various power settings, and their combination, on dentinal orifice occlusion (DOO) as potential treatments for CDH. METHODS: Forty-nine human dentin surfaces were organized into seven equal groups: groups A and B received NM followed by L (0.5 and 1 W, respectively); groups C and D received L (0.5 and 1 W, respectively) followed by NM; group E received NM; and groups F and G received L (0.5 and 1 W, respectively). Specimens were evaluated with regard to DOO under environmental scanning electron microscope. RESULTS: Treatment modality significantly affected DOO (p=0.012). Groups B and G scored higher DOO than the rest. By ordinal logistic regression (with boostrap standard errors), the combination of NM followed by 1 W Nd:YAG laser irradiation (group B) significantly (p<0.001) contributed to DOO, compared with groups A, C, D, E, and F. CONCLUSIONS: Under the limitations of this study, Nd:YAG laser irradiation at 1 W, alone or combined with NM, is a superior method for producing DOO, and may lead to an effective treatment modality for CDH.

In vitro evaluation of dentin tubule occlusion by Denshield and Neodymium-doped yttrium-aluminum-garnet laser irradiation.

INTRODUCTION: This in vitro study evaluated the efficacy of bioglass (Denshield; Novamin Technology, Alachua, FL) and Neodymium-doped yttrium-aluminum-garnet (Nd:YAG) laser irradiation on dentinal tubuli orifice occlusion (DOO) by comparing samples examined under environmental scanning electron microscope (ESEM) after applying each desensitizing approach separately and in combination. METHODS: Forty-eight human molars were collected, randomly organized in 4 equal groups, and had their cervical dentin exposed. Additionally, in half of the specimens of each experimental group, the smear layer was removed (subgroups A1, B1, C1, and D1). Group A received NovaMin paste treatment for 5 minutes (NM) to the experimental surface. Group B received Nd:YAG laser irradiation (0.5 w, 10 Hz, and 50 mJ) (L). Group C received NM followed by L. Group D was treated with L followed by NM. All specimens were stored for 24 hours and evaluated for DOO under ESEM by 4 blinded observers. RESULTS: The presence of a smear layer significantly contributed to DOO regardless of the treatment modality (ordinal logistic regression, P < .001). Compared with group A, all other treatments delivered significantly more occluded dentin orifices (P < .001 for groups B and D and P < .05 for group C). A layer formation was observed in subgroups C2 and D2. CONCLUSIONS: Under these experimental conditions, a smear layer was essential for successful DOO. Laser irradiation alone and combined with NovaMin proved superior to NovaMin alone on DOO. This combined approach has the potential to improve the outcome of treatment for cervical dentin hypersensitivity. The biological significance of this newly formed layer needs to be elucidated.

The use of the erbium, chromium:yttrium-scandium-gallium-garnet laser in endodontic treatment: the results of an in vitro study.

BACKGROUND: The use of the erbium, chromium:yttrium-scandium-gallium-garnet (Er,Cr:YSGG) laser has become accepted in the field of cavity preparation. The development of miniaturized and flexible fiber tips has allowed this device to be used in endodontics. The authors conducted an in vitro study to assess the effects of Er,Cr:YSGG laser irradiation on root canals. METHODS: The authors inoculated root canals with two bacteria, laser irradiated them at two power settings and subjected them to a quantitative microbiological evaluation. They used scanning electron microscopy (SEM) to assess morphological changes in endodontically processed and laser-irradiated root canal walls. They measured temperature increases on the root surface to determine possible thermal side effects. RESULTS: The bacteriological evaluation revealed a disinfecting effect in the root dentin samples that was dependent on the output power but not specific for the bacterial species investigated. SEM showed the removal of the smear layer from the root canal walls and the exposure of dentinal tubules. The temperature rise during irradiation was moderate when standardized power settings were used. CONCLUSIONS: The Er,Cr:YSGG laser can be used to eliminate bacteria in root canals. It also effectively removes smear layer and debris from the canal wall. CLINICAL IMPLICATIONS: Practitioners can use the Er,Cr:YSGG laser to prepare root canals for endodontic therapy.