In situ evaluation of the remineralizing capacity of pit and fissure sealants containing amorphous calcium phosphate and/or fluoride

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

The growing importance of materials that prevent microbial adhesion: antimicrobial effect of medical devices containing silver

Research has clarified the properties required for polymers that resist bacterial colonisation for use in medical devices. The increase in antibiotic-resistant microorganisms has prompted interest in the use of silver as an antimicrobial agent. Silver-based polymers can protect the inner and outer surfaces of devices against the attachment of microorganisms. Thus, this review focuses on the mechanisms of various silver forms as antimicrobial agents against different microorganisms and biofilms as well as the dissociation of silver ions and the resulting reduction in antimicrobial efficacy for medical devices. This work suggests that the characteristics of released silver ions depend on the nature of the silver antimicrobial used and the polymer matrix. In addition, the elementary silver, silver zeolite and silver nanoparticles, used in polymers or as coatings could be used as antimicrobial biomaterials for a variety of promising applications. (C) 2009 Elsevier B. V. and the International Society of Chemotherapy. All rights reserved.

Silver Distribution and Release from an Antimicrobial Denture Base Resin Containing Silver Colloidal Nanoparticles

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Sealability of MTA and calcium hydroxide-containing sealers

Objectives: The aim of this study was to evaluate the apical sealability of Fillapex (R), Endo-CPM-Sealer (R) and Sealapex (R). Material and Methods: Ninety-four freshly extracted single-rooted teeth were selected and decoronated. All teeth were radiographed to confirm the existence of a single and straight root canal, which was prepared using Protaper Universal and 2.5% sodium hypochlorite. The teeth were randomly divided in groups of 10 specimens each according to the sealer, and the canals were filled using the single cone technique and one of the sealers. Four additional teeth were used as controls. The teeth were submitted to dye leakage with Rhodamine B for 24 h but using vacuum on the initial 15 min. Thereafter, they were cut longitudinally and the leakage was measured in a linear fashion from apex to crown. Data were analyzed by ANOVA and Tukey's tests at 5% significance level. Results: Fillapex (R) and Sealapex (R) showed significantly less dye leakage than Endo-CPM-Sealer (R) (p<0.05). Conclusions: It was concluded that Fillapex (R) and Sealapex (R) were able to prevent apical dye leakage differently from Endo-CPM-Sealer (R).

Mechanical and biological characterization of resin-modified glass-ionomer cement containing doxycycline hyclate

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of Candida albicans adhesion and biofilm formation on a denture base acrylic resin containing silver nanoparticles

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Maximum inhibitory dilution of mouthwashes containing chlorhexidine and polyhexamethylene biguanide against salivary Staphylococcus aureus

Objective: The aim of the present study was to determine the in vitro maximum inhibitory dilution (MID) of two chlorhexidine-based oral mouthwashes (CHX): Noplak (R), Periogard (R), and one polyhexamethylene biguanide-based mouthwash (PHMB): Sanifill Premium (R) against 28 field Staphylococcus aureus strains using the agar dilution method. Materials and Methods: For each product, decimal dilutions ranging from 1/10 to 1/655,360 were prepared in distilled water and added to Mueller Hinton Agar culture medium. After homogenization, the culture medium was poured onto Petri dishes. Strains were inoculated using a Steers multipoint inoculator and dishes were incubated at 37 degrees C for 24hours. For reading, MID was considered as the maximum dilution of the mouthwash still capable of inhibiting microbial growth. Results: Sanifill Premium (R) inhibited the growth of all strains at 1/40 dilution and of 1 strain at 1/80 dilution. Noplak (R) inhibited the growth of 23 strains at 1/640 dilution and of all 28 strains at 1/320 dilution. Periogard (R) showed inhibited growth of 7 strains at 1/640 dilution and of all 28 strains at 1/320 dilution. Data were submitted to Kruskal-Wallis statistical test, showing significant differences between the mouthwashes evaluated (p<0.05). No significant difference was found between Noplak (R) and Periogard (R) (p>0.05). Sanifill Premium (R) was the least effective (p<0.05). Conclusion: It was concluded that CHX-based mouthwashes present better antimicrobial activity against S. Aureus than the PHMB-based mouthwash.

pH and calcium ion release evaluation of pure and calcium hydroxide-containing Epiphany for use in retrograde filling

Objective: Hydroxyl (OH(-)) and calcium (Ca(++)) ion release was evaluated in six materials: G1) Sealer 26, G2) White mineral trioxide aggregate (MTA), G3) Epiphany, G4) Epiphany + 10% calcium hydroxide (CH), G5) Epiphany + 20% CH, and G6) zinc oxide and eugenol. Material and Methods: Specimens were placed in polyethylene tubes and immersed in distilled water. After 3, 6, 12, 24, and 48 h, 7, 14, and 28 days, the water was assessed for pH with a pH meter and for Ca++ release by atomic absorption spectrophotometry. Results: G1, G2, G4, and G5 had the highest pH until 14 days (p < 0.05). G1 presented the highest Ca(++) release until 6 h, and G4 and G5, from 12 h through 14 days. Ca(++) release was greater for G1 and G2 at 28 days. G6 released the least Ca(++). Conclusions: MTA, Sealer 26, Epiphany, and Epiphany + CH release OH-and Ca(++) ions. Epiphany + CH may be an alternative as retrofilling material.

Evaluation of pH and Calcium Ion Release of Calcium Hydroxide Pastes Containing Different Substances

Introduction: The objective of this study was to evaluate the pH and calcium ion release of calcium hydroxide pastes associated with different substances. Methods: Forty acrylic teeth with simulated root canals were divided into 4 groups according to the substance associated to the calcium hydroxide paste: chlorhexidine (CHX) in 2 formulations (1% solution and 2% gel), Casearia sylvestris Sw extract, and propylene glycol (control). The teeth with pastes and sealed coronal accesses were immersed in 10 mL deionized water. After 10 minutes, 24 hours, 48 hours, and 7, 15, and 30 days, the teeth were removed to another container, and the liquid was analyzed. Calcium ion release was measured by atomic absorption spectrophotometry, and pH readings were made with a pH meter. Data were analyzed statistically by analysis of variance and Tukey test (alpha = 0.05). Results: Calcium analysis revealed significant differences (P < .05) for 1% CHX solution and 2% CHX gel at 10 minutes. After 24 hours, 2% CHX gel x Control and 2% CHX gel x 1% CHX solution differed significantly (P < .05). After 48 hours, there were significant differences (P < .05) for 2% CHX gel x Control and Extract x Control. No differences (P > .05) were observed among groups in the other periods. Regarding the pH, there were significant differences (P < .05) for 2% CHX gel x Control and 2% CHX gel x 1% CHX solution after 48 hours and for 2% CHX gel x Control after 15 days. In the other periods, no differences (P > .05) were observed among groups. Conclusions: All pastes behaved similarly in terms of pH and calcium ion release in the studied periods. (J Endod 2009;35:1274-1277)

Evaluation of pH and Calcium Ion Release of Root-end Filling Materials Containing Calcium Hydroxide or Mineral Trioxide Aggregate

Introduction: To evaluate calcium ion release and pH of Sealer 26 (S26) (Dentsply, Rio de Janeiro, RJ, Brazil), white mineral trioxide aggregate (MTA), Endo CPM Sealer (CPM1) (EGEO SRL Bajo licencia MTM Argentina SA, Buenos Aires, Argentina), Endo CPM Sealer in a thicker consistency (CPM 2), and zinc oxide and eugenol cement (ZOE). Methods: Material samples (n = 10) were placed in polyethylene tubes and immersed in 10 mL of distilled water. After 3, 6,12,24, and 48 hours and 7,14, and 28 days, the water pH was determined with a pH meter, and calcium release was assessed by atomic absorption spectrophotometry. An empty tube was used as the control group. Results: The control group presented a pH value of 6.9 at all studied periods and did not show the presence of calcium ion. S26 presented greater hydroxyl ion release up to 12 hours (p < 0.05). From 24 hours until 28 days, S26, MTA, CPM1, and CPM2 had similar results. in ail periods, ZOE presented the lowest hydroxyl ion release. CPM1, followed by CPM2, released the most calcium ions until 24 hours (p < 0.05). Between 48 hours and 7 days, CPM1 and CPM2 had the highest release. A greater calcium ion release was observed for CPM2, followed by CPM1 at 14 days and for S26, CPM1, and CPM2 at 28 days. ZOE released the least calcium ions in all periods. Conclusion: Sealer 26, MTA, and Endo CPM sealer at normal or thicker consistency release hydroxyl and calcium ions. Endo CPM sealer may be an alternative as root-end filling material. (J Endod 2009;35:1418-1421)

Determination of the properties of an experimental glass polyalkenoate cement prepared from niobium silicate powder containing fluoride

Objectives. The purpose of this paper is to modify the conventional calcium fluoro-aluminosilicate glass, which is used in the formation of glass ionomer cements (CIGs) by the niobium addition and to study the properties of GICs obtained.Materials and methods. Sol-gel process was used to prepare the powder at lower temperature than fusion method. Glass-ceramic powder obtained in this way was used to prepare the GICs. The properties such as working and setting times, microhardness and diametral tensile strength were evaluated for the experimental GICs and a commercial luting cement.Results. The ideal powder:liquid (P:L) ratio determined to prepare the experimental GICs was equal to 1:1. The cements prepared using this ratio showed working and setting times similar to the commercial GICs. in mechanical tests it was observed that microhardness and diametral tensile strength of the experimental GICs decreased significantly with the reduction of P:L ratio. on the other hand, the results obtained in microhardness tests indicated that the presence of niobium was a positive factor.Significance. The chemical process allows the development of glass-ceramic powder at 600 degrees C which is the goal of the present paper. It was concluded that GICs containing niobium might be used in dental applications and these results encourage further researches on other compositions. (c) 2007 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Response of mice connective tissue to intracanal dressings containing chlorhexidine

Substances containing chlorhexidine (CHX) have been studied as intracanal medicaments. The aim of the present study was to characterize the response of mouse subcutaneous connective tissue to CHX-containing medications by conventional optical microscopy. The tissue response was evaluated by implanting polyethylene tubes containing one of the substances evaluated: Calen paste + 0.5% CHX, Calen + 2% CHX, 2% CHX gel, and Calen paste (control). After experimental periods of 7, 21, and 63 days, the implants (n = 10) were removed along with the subcutaneous connective tissue. Tissue samples were subjected to histological processing, and sections were stained with hematoxylin and eosin. Qualitative and quantitative analyses of the number of inflammatory cells, blood vessels, and vascularized areas were performed. Results were analyzed by ANOVA and Tukey tests with the significance level set at 5%. We concluded that Calen + 0.5% CHX led to reparative tissue response in contrast with Calen + 2% CHX and 2% CHX gel, which induced persistent inflammatory response, pointing to the aggressive nature of this mixture. When Calen + 2% CHX and 2% CHX gel were compared, the latter induced more intense inflammatory response. Microsc. Res. Tech., 2012. (C) 2012 Wiley Periodicals, Inc.

Antibacterial activity of four mouthrinses containing triclosan against salivary Staphylococcus aureus

A Diluição Inibitória Máxima (DIM) de anti-sépticos bucais à base de triclosan contra 28 cepas de Staphylococcus aureus foi avaliada. Diluições de 1/10 a 1/655.360 foram preparadas. As cepas foram inoculadas com inoculador multipontual Steers. A DIM foi a maior diluição do anti-séptico que inibiu crescimento microbiano. Os anti-sépticos apresentaram diferentes DIMs.

Growth performance of Nile tilapia, Oreochromis niloticus, fed diets containing levels of pyridoxine and haematological response under heat stress

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Performance and egg quality of laying hens fed diets containing aflatoxin, fumonisin and adsorbent

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)