Effectiveness of 6% hydrogen peroxide concentration for tooth bleaching­A double-blind, randomized clinical trial.

OBJECTIVE: The aim of this clinical randomized double-blind split-mouth study was to assess the effectiveness of a 6% hydrogen peroxide with nitrogen-doped titanium dioxide light activated bleaching agent. METHOD: 31 patients were treated with: one upper hemiarcade with a 35% hydrogen peroxide bleaching agent and the other hemiarcade with a 6% hydrogen peroxide. Two applications were completed each treatment session and three sessions were appointed, with one week interval between them. Tooth colour was registered each session and 1 week and 1 months after completing the treatment by spectrophotometer, registering parameters L*, a* and b*, and subjectively using VITA Classic guide. Tooth sensitivity was registered by VAS and patient satisfaction and self-perception result was determined using OHIP-14. Tooth colour variation and sensitivity were compared between both bleaching agents. RESULTS: Both treatment showed a change between baseline colour and all check-points with a ΔE=5.57 for 6% and of ΔE=7.98 for the 35% one month after completing the (p<0.05). No statistical differences were seen when subjective evaluations were compared. Also, no differences were seen in tooth sensitivity between bleaching agents. OHIP-14 questionnaire demonstrated a significant change for all patients after bleaching. CONCLUSIONS: A 6% hydrogen peroxide with nitrogen-doped titanium dioxide light activated agent is effective for tooth bleaching, reaching a ΔE of 5.57 one month after completing the treatment, with no clinical differences to a 35% agent neither in colour change or in tooth sensitivity. CLINICAL SIGNIFICANCE: A low concentration hydrogen peroxide bleaching agent may reach good clinical results with less adverse effects.

Correlation between oral health perception and clinical factors in a Brazilian community.

OBJECTIVE: The aim of this study was to analyse associations between self-perception of oral health and relevant clinical, personal and socio-demographic factors in a Brazilian community. MATERIAL AND METHODS: Urban adults living in a city in southern Brazil were interviewerd and examined. Individuals with acute pain and who needed multiple extractions of teeth were excluded. Self-perception and the Oral Health Impact Profile (OHIP-14) were applied to measure the impact of oral conditions on the quality of life. Socio-demographic and clinical indicators were also analysed. RESULTS: The clinical examination revealed a high dental caries experience (DMFT = 18.9) and a high prevalence of periodontal disease. Oral condition was considered "normal" by 42% of respondents. The variables associated with the OHIP-14 were: education, age, self-assessment, dental caries and the DMFT index. CONCLUSIONS: Self-perception of oral health was associated with OHIP-14 and the clinical indicators had low influence in the self-perception. Therefore, the development of educational initiatives and preventive strategies for the adult population is recommended.

Antibacterial and antioxidant activities of the essential oil of Artemisia echegarayi Hieron. (Asteraceae) / Actividad antibacteriana y antioxidante del aceite esencial extraído de Artemisia echegarayi Hieron. (Asteraceae)

Artemisia echegarayi Hieron. (Asteraceae) is commonly known in Argentina as “ajenjo”. Many studies report high efficacy of essential oils against food-borne pathogenic bacteria. The antimicrobial activity and minimal inhibitory concentration of A. echegarayi essential oil were evaluated against seven bacterial species of significant importance in food hygiene, by using the disc diffusion assay and the micro-well dilution method, respectively. Volatile components of the extract were analyzed by gas chromatography-mass spectrometry and major components were determined. Furthermore, the essential oil was tested for its antioxidant activity. The essential oil inhibited the growth of gram-positive and gram-negative tested bacteria, with the exception of Proteus mirabilis. A. echegarayi essential oil presented the lowest minimal inhibitory concentration against Listeria monocytogenes and Bacillus cereus. Two terpenes, thujone and camphor, were identified from this essential oil as the principal constituents responsible for antibacterial activity. The oil showed a free radical scavenging activity equivalent to 50% of the reference compound. These preliminary studies showed promising results since this essential oil may provide an alternative to promote its use as a natural food additive.

Artemisia echegarayi Hieron. (Asteraceae), conocida como “ajenjo”, es una planta típica de la región de Cuyo (Argentina). En este trabajo se evaluó la actividad antimicrobiana in vitro y la concentración inhibitoria mínima del aceite esencial extraído de sus partes aéreas frente a especies bacterianas que con frecuencia contaminan los alimentos. Se utilizaron las técnicas de difusión con discos en agar y microdilución en placa respectivamente. Además, se determinó la actividad antioxidante de este aceite esencial in vitro por espectrofotometría. En general, tanto las bacterias gram-positivas como las gram-negativas fueron inhibidas por este aceite, con excepción de Proteus mirabilis. Listeria monocytogenes y Bacillus cereus resultaron ser las bacterias más sensibles. El análisis por croma-tografía en fase gaseosa y espectrometría de masa permitió la identificación cualitativa y cuantitativa de los componentes mayoritarios del aceite esencial del ajenjo. Entre ellos, la tuyona y el alcanfor se destacaron como los principales responsables de la actividad antibacteriana observada. Los datos preliminares obtenidos en el presente estudio sugieren que el aceite esencial de Artemisia echegarayi representa una alternativa para promover su empleo como aditivo natural en alimentos.

Antibacterial and antioxidant activities of the essential oil of Artemisia echegarayi Hieron. (Asteraceae).

Artemisia echegarayi Hieron. (Asteraceae) is commonly known in Argentina as "ajenjo". Many studies report high efficacy of essential oils against food-borne pathogenic bacteria. The antimicrobial activity and minimal inhibitory concentration of A. echegarayi essential oil were evaluated against seven bacterial species of significant importance in food hygiene, by using the disc diffusion assay and the micro-well dilution method, respectively. Volatile components of the extract were analyzed by gas chromatography-mass spectrometry and major components were determined. Furthermore, the essential oil was tested for its antioxidant activity. The essential oil inhibited the growth of gram-positive and gram-negative tested bacteria, with the exception of Proteus mirabilis. A. echegarayi essential oil presented the lowest minimal inhibitory concentration against Listeria monocytogenes and Bacillus cereus. Two terpenes, thujone and camphor, were identified from this essential oil as the principal constituents responsible for antibacterial activity. The oil showed a free radical scavenging activity equivalent to 50% of the reference compound. These preliminary studies showed promising results since this essential oil may provide an alternative to promote its use as a natural food additive.

Evaluation of diuretic activity of the constituents of Clematis montevidensis Spreng. (Ranunculaceae) in rats.

The effects of Clematis montevidensis Spreng. (Ranunculaceae) on urinary excretion of water, sodium and potassium were investigated in rats loaded with isotonic saline solution. The data reported in the present work indicate that the infusions of the root and aerial part of Clematis montevidensis showed a moderate diuretic activity. This effect could be due, at least in part, to the presence of oleanolic acid isolated from this plant.

Diuretic activity of Fabiana patagonica in rats.

A pharmacological evaluation of the diuretic activity of Fabiana patagonica Speg. (Solanaceae) was carried out in isotonic saline loaded rats. The data reported in the present work indicate that the acetone extract and infusion of the aerial part of Fabiana patagonica showed a moderate diuretic activity. This activity could be due, in part, to the presence of oleanolic acid isolated as the major metabolite of F. patagonica.

Phytochemical study and anti-inflammatory properties of Lampaya hieronymi Schum. ex Moldenke.

The chemical study of aerial parts of Lampaya hieronymi Schum. ex Moldenke yielded oleanolic acid, epi-oleanolic acid, epi-maslinic acid, 4'7-dimethoxyapigenin, p-hydroxyacetophenone, and p-hydroxyacetophenone-beta-glucoside. In searching for natural products as potential anti-inflammatory agents, all the compounds, except 4'7-dimethoxyapigenin were evaluated in vivo for their ability to inhibit acute inflammation. Our studies demonstrated that p-hydroxyacetophenone and the triterpenes produced protective effects in carrageenan induced paw edema in mouse, at 1-3 h and 3-5 h, respectively, after the injection of carrageenan. These results indicated that their effects might correlate with the release of histamine, serotonin, kinin and prostaglandins.

Composite surfaces after finishing and polishing techniques.

PURPOSE: To evaluate the effect of finishing and polishing techniques on surface roughness of resin-based composites (RBCs). MATERIALS AND METHODS: Forty specimens of each material were cured under Mylar strips and immersed in artificial saliva for 1 wk. Samples were tested with a profilometer to obtain baseline average surface roughness (Ra). Specimens of both RBCs were then finished and polished according to four techniques: (1) Sof-Lex disks; (2) Sof-Lex disks followed by Prisma Gloss; (3) Enhance points; (4) Enhance points followed by Prisma Gloss application. New readings of the roughness pattern were carried out and the difference of post-polishing and baseline values were analyzed. RESULTS: ANOVA test (alpha = 0.05) did not show differences between materials (P = 0.9393) nor interaction effects (P = 0.3094), but significant difference among the finishing/polishing techniques were detected (P = 0.0157). Tukey's test showed that the smoothest surface was obtained when the specimens were treated by Sof-Lex followed by Prisma Gloss polishing paste; and the worst results were obtained after using Enhance points alone.

Structure-activity relationship in the gastric cytoprotective effect of several sesquiterpene lactones.

The structural requirements for the gastric cytoprotective activity of several sesquiterpene lactones are reported. A theoretical-experimental study on the potentially active centers is carried out. The biological evaluation of reduced analogues and the simulation of the molecular interactions between these compounds and an endogenous cysteine residue suggest that the presence of a non sterically hindered Michael acceptor seems to be an essential structural requirement for the cytoprotective activity in this family of compounds. This observation suggests that cytoprotection is mediated through a Michael reaction between the sulfhydryl-containing peptides of the mucosa and Michael acceptors present in the molecules under study. This mechanism of action is in addition to and distinct from the one proposed in our previous paper, namely, that these sesquiterpenes stimulate endogenous synthesis of prostaglandins.