1.The influence of saliva pH value on the retention and durability of bar-clip attachments.
Antonio Sergio SILVA ; Carlos AROSO ; Raul USTRELL ; Ana Cristina BRAGA ; Jose Manuel MENDES ; Tomas ESCUIN
The Journal of Advanced Prosthodontics 2015;7(1):32-38
PURPOSE: The aim of this study was to compare the durability and retention of 4 types of attachments placed over computer aided design/computer aided manufacturing (CAD/CAM) titanium bars when subjected to different pH conditions. MATERIALS AND METHODS: Four commercially available attachments were investigated: Hader Yellow, Hader Red, Ackerman Gold and Ackerman Stainless Steel. These attachments and Ackerman CAD/CAM titanium bars were placed in 2 vessels containing different artificial saliva solutions (pH 7/pH 4) at 37degrees C for one month to simulate corrosion conditions, and they were then subjected to mechanical testing (5400 cycles of insertion and removal). RESULTS: The results revealed that there were significant differences in the average values of insertion/removal force due to the pH (F (1, 24)=9.207, P<.05) and the type of attachment (F (3, 24)=11.742, P<.05). CONCLUSION: More acidic pH values were found to have a negative influence on the retention capacity of the attachments.
Corrosion
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Dental Implants
;
Denture, Overlay
;
Hydrogen-Ion Concentration*
;
Saliva*
;
Saliva, Artificial
;
Stainless Steel
;
Titanium
2.Formation of DNA strand breaks in peripheral lymphocytes of rats after exposure to natural sunlight.
Dorival Mendes RODRIGUES-JUNIOR ; Ana Amélia de Carvalho MELO ; Benedito Borges da SILVA ; Pedro Vitor LOPES-COSTA
Biomedical and Environmental Sciences 2012;25(2):245-249
OBJECTIVEThis paper aims to evaluate the genotoxicity in peripheral blood lymphocytes of rats after exposure to sunlight at different time points of day in a tropical region of Brazil (5 degrees S, 42 degrees W).
MATERIALS AND METHODSThirty Wistar-Hannover rats, three months old, were randomly divided into three groups of 10 animals each: Group I [control, without exposure to ultraviolet (UV) radiation], Group II (exposed to sunlight during 08:00 a.m. to 10:00 a.m.), and Group III (exposed to sunlight during 10:00 a.m. to 12:00 a.m.). After a week of exposure, peripheral blood samples were taken from the tail of these animals to prepare smears on two slides per animal. In 24 h after exposure to sunlight in Group III, a new collection was obtained to observe the repair activity. The alkaline comet assay was used in this study to evaluate the genotoxic activity of sunlight (P < 0.05).
RESULTSThere was no statistical difference between Group I and II (P = 0.672). On the other hand, the exposure to sunlight in Group III showed genotoxic action in comparison to the other groups (P < 0.0001). Also, there was no significant repair in Group III R (P = 0.407).
CONCLUSIONThis study has shown a genotoxic potential of sunlight (UVA-B) in lymphocytes of mammals from 10:00 a.m. to 12:00 a.m., due to a higher intensity of UV in this tropical region.
Animals ; Comet Assay ; DNA Damage ; Lymphocytes ; radiation effects ; Rats ; Rats, Wistar ; Sunlight
3.Effect of abutment angulation in the retention and durability of three overdenture attachment systems: An in vitro study.
Carlos AROSO ; Antonio Sergio SILVA ; Raul USTRELL ; Jose Manuel MENDES ; Ana Cristina BRAGA ; Esther BERASTEGUI ; Tomas ESCUIN
The Journal of Advanced Prosthodontics 2016;8(1):21-29
PURPOSE: This in vitro study investigated and compared the durability and retention of three types of attachments. MATERIALS AND METHODS: Three commercially available attachments were investigated: Clix(R), Dalbo-Plus(R) and Locator(R). In total, 72 samples of these attachments were placed in the acrylic resin forms and subjected to mechanical testing (5400 cycles of insertion and removal) over the respective ball or Locator abutments immersed in artificial saliva at pH 7 and 37degrees C. The abutments were placed at angulations of 0degrees, 10degrees and 20degrees. The retention force was recorded at the beginning and after 540, 1080, 2160, 3240, 4320 and 5400 insertion-removal cycles. RESULTS: The results revealed that there were significant differences in the average values of the insertion/removal force due to angulation (F (2.48) = 343619, P<.05) and the type of attachment (F (7.48) = 23.220, P<.05). CONCLUSION: Greater angulation of the abutments was found to influence the retention capacity of the attachments, and the fatigue test simulating 5 years of denture insertion and removal did not produce wear in the metal abutments.
Dental Implants
;
Denture, Overlay*
;
Dentures
;
Fatigue
;
Hydrogen-Ion Concentration
;
Saliva, Artificial
4.Anaphylaxis caused by honey: a case report
Rita AGUIAR ; Fátima Cabral DUARTE ; Ana MENDES ; Borja BARTOLOMÉ ; Manuel Pereira BARBOSA
Asia Pacific Allergy 2017;7(1):48-50
Honey allergy is a very rare, but serious health condition. In this study, we presented 1 patient who had anaphylaxis after the honey allergological investigation with skin prick-prick test with honey. Honey as a food has been associated to allergic reactions and as the increased consumption of honey in health food may increase the incidence of honey-related allergic reactions.
Anaphylaxis
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Honey
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Humans
;
Hypersensitivity
;
Incidence
;
Skin
5. Anti-Candida and anti-Cryptococcus evaluation of 15 non-alkaloidal compounds from Pterogyne nitens
Caroline Sprengel LIMA ; Carlos Roberto POLAQUINI ; Mariana Bastos dos SANTOS ; Luis Octavio REGASINI ; Fernanda Patrícia GULLO ; Fernanda Sangalli LEITE ; Liliane SCORZONI ; Maria José Soares MENDES-GIANNINI ; Ana Marisa FUSCO-ALMEIDA ; Vanderlan da Silva BOLZANI ; Andréia Alves REZENDE
Asian Pacific Journal of Tropical Biomedicine 2016;6(10):841-845
Objective To evaluate anti-Candida and anti-Cryptococcus activities of 15 non-alkaloidal compounds from Pterogyne nitens Tulasne (Leguminosae), a South American medicinal plant. Methods Compounds were submitted to antifungal assays, using microdilution method described by Clinical and Laboratory Standards Institute document, with minor modifications. Five species of Candida and two species of Cryptococcus, including clinical isolates were screened. Antifungal activity was expressed by minimum inhibitory concentration (MIC). Amphotericin B and fluconazole were used as standard antifungal drugs. Results Among tested compounds, six substances presented fungal growth inhibition (MIC < 31.2 μg/mL) [three flavone derivatives (1–3), a glycosylated flavonol derivative (5) and two phenolic acids (10 and 12)]. Sorbifolin (1), exhibited potent antifungal activity, demonstrating MIC value of 3.90 μg/mL against Candida glabrata ATCC 90030, Cryptococcus gattii 118 and fluconazole-resistant clinical isolate of Cryptococcus neoformans var. grubii. Pedalin (2) and nitensoside B (3), two glycosylated flavone derivatives, were active against Cryptococcus neoformans ATCC 90012 (MIC = 7.80 μg/mL). Conclusions Flavone derivatives from Pterogyne nitens can serve as prototypes for the design and development of innovative anti-Candida and anti-Cryptococcus hits.