Hipersensibilidade dentinária cervical: em busca de um tratamento eficaz

The knowledge of the etiology of any disease or condition is paramount to a safe and effective treatment. This literature review aims to show some options to treat dentine hypersensitivity (HSDC). The loss of cervical enamel and cementum exposure of tubules leads to a painful condition and patient discomfort, called HSDC. This loss of tooth structure occurs due to formation of cervical lesions in cases of gingival recession, abrasion, erosion, or abfraction by the association of two or more factors. Some treatments are not effective, but there are effective therapies, such as: application of ferric oxalate, potassium oxalate, potassium nitrate, fluoride varnish, solutions of calcium phosphate, adhesives and Bonding procedures. Therefore, the identification and removal of etiological factors is essential to successful treatment of HSDC normally associated to tubules obliterate and consequent reduction of fluid motion within the dentin.

Effectiveness of ProTaper retreatment system associated with organic solvents in the removal of root canal filling material

Aim: To evaluate the effectiveness of ProTaper universal retreatment system in the removal of root canal filling material with thermomechanical compaction, in comparison to manualmechanical technique, associated with orange oil or eucalyptol. Materials and methods: Forty extracted lower incisors were filled with thermomechanical compaction technique. After 3 years, the root canal filling was removed by: G1 - manualmechanical technique with orange oil; G2 - manual-mechanical technique with eucalyptol; G3 - ProTaper universal retreatment system with orange oil and G4 - ProTaper universal retreatment system with eucalyptol. In sequence, all root canals were instrumented to F5 instrument. The teeth were longitudinally grooved, images of buccal half were obtained in stereomicroscope and covered area by root canal filling material was measured using image tool software, in cervical, middle and apical radicular thirds. The results were subjected ANOVA and Tukey test (p = 0.05). Results: In all thirds, the manual-mechanical technique showed lower presence of root canal filling material on root canal dentin in comparison to ProTaper retreatment universal system, regardless of organic solvent used (p < 0.05). There is no difference between organic solvents in removal root canal filling material (p > 0.05). Conclusion: The ProTaper universal retreatment system showed lower effectiveness in removal root canal filling material than manual-mechanical technique, regardless of organic solvents (orange oil or eucalyptol oil) used. Clinical significance: Recently rotary instruments have been proposed to removal of root canal filling material. However, there are no studies evaluating its effectiveness in removal root canal filling material in association with orange oil or eucalyptol oil.

Methods for removal of resin remaining after debonding of orthodontic brackets: a literature review

The removal of resin debris and/or resin cement from the enamel surface without causing iatrogenic is the main objective when removing the orthodontic brackets. Some factors such as the time required for removal, damage to the tooth structure, are essential factors for the clinician at the time of removal. Various techniques are used for the removal of orthodontic brackets after the treatment; it is known that the use of clinical procedures such as the use of diamond burs and some pliers removers can damage the structure of the enamel, often depending on the bond strength that should be taken into consideration at the time of removal. This literature review aims to gather the most relevant studies that can clarify the clinical technique, which may be more suitable for removal of the brackets.

Double-setting alpha-tricalcium phosphate cement provided with interconection channels in rabbits after enucleation: a potential implant for the anophthalmic socket

The purpose of this study was to evaluate the macroscopy and microstructure of a double setting alpha-tricalcium phosphate bone cement sphere provided with interconnection channels (alpha-TCP-i), as well as the integration of the implant with the rabbits' orbital tissue, through macroscopic analysis and histopathology. The external and internal surfaces of the alpha-TCP-i were evaluated macroscopically and by electron microscopy. Twelve New Zealand rabbits received 12mm implants of alpha-TCP-i following enucleation of the left eye. The clinical assessment was undertaken daily during the first 15 days, followed by fortnightly assessment until the end of the study period. For the morphological analysis, exenteration was performed in 3 animals per experimental period (15, 45, 90 and 180 days). The external and internal surfaces of the implant appeared solid, smooth and compact, with six channels which interconnected centrally. The micro-architecture was characterized by the formation of columns of hexagonal crystals. No signs of infection, exposure, dehiscence of sutures or extrusion of the implant were noted in any of the animals during the entire period of the study. The morphological evaluation demonstrated the presence of a thin capsule around the implant, from whence appeared fibro-vascular projections, which penetrated it through the interconnecting channels. In the first days after the insertion of the implant, an intense inflammatory reaction was noted. At 180 days, however, there were no signs of inflammation. The alpha-tricalcium phosphate cement implant was well tolerated in this rabbit model and appeared to be relatively inert with some fibrovascular ingrowth through the large channels.

Removal of glyphosate herbicide from water using biopolymer membranes

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

Removal of reactive dye from aqueous solution using thermally treated red mud

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

Analysis of anticaries potential of pit and fissures sealants containing amorphous calcium phosphate using synchrotron microtomography

The aim of this study was to analyze the anticaries potential of pit and fissure sealants containing amorphous calcium phosphate (ACP) by synchrotron microtomography. Bovine enamel blocks (4x4 mm; n=50) were selected through surface hardness (Knoop) analysis. Slabs were obtained through cross-sections taken 1 mm from the border of the enamel. Five indentations, spaced 100 mu m apart, were made 300 mu m from the border. Ten specimens were prepared for each tested material (Ultraseal XT plus TM, Aegis, Embrace, Vitremer and Experimental Sealant). The materials were randomly attached to the sectioned surfaces of the enamel blocks and fixed with sticky wax. The specimens were submitted to pH cycling. After that, the surface hardness (SH1) was determined, and the blocks were submitted to synchrotron microcomputed tomography analysis to calculate the mineral concentration (Delta g(HAp) cm(-3)) at different areas of the enamel. The comparison between the SH1 and DgHAp cm(-3) showed a correlation for all groups (r=0.840; p<0.001). The fluoride groups presented positive values of DgHAp cm(-3), indicating a mineral gain that was observed mainly in the outer part of the enamel. The ACP showed mineral loss in the outer enamel compared with fluoride groups, although it inhibited the demineralization in the deeper areas of enamel. The combination of two remineralizing agents (fluoride and ACP) was highly effective in preventing demineralization.

Glyceraldehyde 3-phosphate dehydrogenase-telomere association correlates with redox status in trypanosoma cruzi

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

Chemotactic signal transduction and phosphate metabolism as adaptive strategies during citrus canker induction by Xanthomonas citri

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

Study on determination and removal of metallic ions from aqueous and alcoholic solutions using a new POSS adsorbent

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

Characterization of calcium phosphate coating produced by biomimetic method

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

Effects of protein supplementation frequency on physiological responses associated with reproduction in beef cows

The objective of this experiment was to determine if frequency of protein supplementation impacts physiological responses associated with reproduction in beef cows. Fourteen nonpregnant, nonlactating beef cows were ranked by age and BW and allocated to 3 groups. Groups were assigned to a 3 x 3 Latin square design, containing 3 periods of 21 d and the following treatments: 1) soybean meal supplementation daily (D), 2) soybean meal supplementation 3 times/week (3WK), and 3) soybean meal supplementation once/week (1WK). Within each period, cows were assigned to an estrus synchronization protocol: 100 mu g of GnRH + controlled internal drug release device (CIDR) containing 1.38 g of progesterone (P-4) on d 1, 25 mg of PGF(2 alpha) on d 8, and CIDR removal + 100 mu g of GnRH on d 11. Grass-seed straw was offered for ad libitum consumption. Soybean meal was individually supplemented at a daily rate of 1 kg/cow (as-fed basis). Moreover, 3WK was supplemented on d 0, 2, 4, 7, 9, 11, 14, 16, and 18 whereas 1WK was supplemented on d 4, 11, and 18. Blood samples were collected from 0 (before) to 72 h after supplementation on d 11 and 18 and analyzed for plasma urea-N (PUN). Samples collected from 0 to 12 h were also analyzed for plasma glucose, insulin, and P-4 (d 18 only). Uterine flushing fluid was collected concurrently with blood sampling at 28 h for pH evaluation. Liver biopsies were performed concurrently with blood sampling at 0, 4, and 28 h and analyzed for mRNA expression of carbamoyl phosphate synthetase I (CPS-I; h 28) and CYP2C19 and CYP3A4 (h 0 and 4 on d 18). Plasma urea-N concentrations were greater (P < 0.01) for 1WK vs. 3WK from 20 to 72 h and greater (P < 0.01) for 1WK vs. D from 16 to 48 h and at 72 h after supplementation (treatment x hour interaction, P < 0.01). Moreover, PUN concentrations peaked at 28 h after supplementation for 3WK and 1WK (P < 0.01) and were greater (P < 0.01) at this time for 1WK vs. 3WK and D and for 3WK vs. D. Expression of CPS-I was greater (P < 0.01) for 1WK vs. D and 3WK. Uterine flushing pH tended (P <= 0.10) to be greater for 1WK vs. 3WK and D. No treatment effects were detected (P >= 0.15) on expression of CYP2C19 and CYP3A4, plasma glucose, and P-4 concentrations, whereas plasma insulin concentrations were greater (P <= 0.03) in D and 3WK vs. 1WK. Hence, decreasing frequency of protein supplementation did not reduce uterine flushing pH or plasma P-4 concentrations, which are known to impact reproduction in beef cows.

Mapping of clay, iron oxide and adsorbed phosphate in Oxisols using diffuse reflectance spectroscopy

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

Delayed tooth replantation: MTA as root canal filling

MTA has been investigated as a root-end filling material. Its mechanism of action has some similarities to that of Ca(OH())2. The purpose of this study was to evaluate the repair process taking place in the delayed replantation of monkey teeth using calcium hydroxide and MTA as root canal filling materials. Five monkeys had their lateral incisors extracted and bench-dried for 60 minutes. After root canal preparation, the teeth were assigned to two groups according to root canal filling material: I, calcium hydroxide; and II, MTA. The same treatment sequence was followed for both groups: coronal seal, periodontal ligament removal, immersion of the tooth in 2% acidulated-phosphate sodium fluoride, irrigation of the socket with saline and replantation. Both groups exhibited replacement resorption, areas of ankylosis and absence of inflammatory root resorption. Statistically similar results (p > 0.05) were observed for both groups regarding replacement root resorption, but the groups differed significantly (p < 0.05) regarding the occurrence of ankylosis. MTA may be a viable clinical option for filling teeth submitted to delayed replantation, and is an acceptable option for treating replanted permanent teeth in order to prevent tooth resorption, particularly when dressing changes are not possible.

Removal of clay by stingless bees: load size and moisture selection

Some organisms disperse energy, associated with the transportation of resource, which is not necessarily food. Stingless bees of Central Amazonia (Melipona flavolineata and M. lateralis) collect clay in banks along streams for nest building. The moisture of the clay varies along the bank, and bees collect clay from specific location, indicating that there is some sort of preference regarding their selection. This study aims at identifying: if larger bees carry more clay; if there is a preference for moisture of substrates; and if bees are less efficient accumulating and transporting clay when it is wet. In order to do so, I measured the size of the bees and of the pellets of clay found in the corbicula. I set up a field experiment to test substrate preferences. The amount of clay transported, increased exponentially in accordance to the size of the bee, and the preferred substrate was the driest clay. The amount and the efficiency of removal of clay were not affected by the moisture of the substrate. Despite the wet clay being denser, it does not reduce the efficiency of exploitation of the resource, but suggests that bees spend more energy to carry the same quantity of wet clay, which may be the underlying mechanism explaining their preference for removing drier clay.