Oxytocin promotes bone formation during the alveolar healing process in old acyclic female rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of enamel matrix derivative (Emdogain((R))) and sodium fluoride on the healing process in delayed tooth replantation: histologic and histometric analysis in rats

Although it has already been shown that enamel matrix derivative (Emdogain((R))) promotes periodontal regeneration in the treatment of intrabony periodontal defects, there is little information concerning its regenerative capacity in cases of delayed tooth replantation. To evaluate the alterations in the periodontal healing of replanted teeth after use of Emdogain((R)), the central incisors of 24 Wistar rats (Rattus norvegicus albinus) were extracted and left on the bench for 6 h. Thereafter, the dental papilla and the enamel organ of each tooth were sectioned for pulp removal by a retrograde way and the canal was irrigated with 1% sodium hypochlorite. The teeth were assigned to two groups:in group I, root surface was treated with 1% sodium hypochlorite for 10 min (changing the solution every 5 min), rinsed with saline for 10 min and immersed in 2% acidulated-phosphate sodium fluoride for 10 min; in group II, root surfaces were treated in the same way as described above, except for the application of Emdogain((R)) instead of sodium fluoride. The teeth were filled with calcium hydroxide (in group II right before Emdogain((R)) was applied) and replanted. All animals received antibiotic therapy. The rats were killed by anesthetic overdose 10 and 60 days after replantation. The pieces containing the replanted teeth were removed, fixated, decalcified and paraffin-embedded. Semi-serial 6-mu m-thick sections were obtained and stained with hematoxylin and eosin for histologic and histometric analyses. The use of 2% acidulated-phosphate sodium fluoride provided more areas of replacement resorption. The use of Emdogain((R)) resulted in more areas of ankylosis and was therefore not able to avoid dentoalveolar ankylosis. It may be concluded that neither 2% acidulated-phosphate sodium fluoride nor Emdogain((R)) were able to prevent root resorption in delayed tooth replantation in rats.

Healing process of incisor teeth of diabetic rats replanted after storage in milk

Several local factors that influence the healing process of replanted teeth have been investigated. However, it remains unclear how systemic alterations, such as diabetes mellitus, affect the prognosis of these cases. The purpose of this study was to evaluate the healing process of incisors of non-controlled diabetic rats replanted after storage in bovine long shelf-life (UHT) whole milk. Thirty-two rats were randomly assigned to receive an endovenous injection of either citrate buffer solution (group I - control; n = 16) or streptozotocin dissolved in citrate buffer solution to induce diabetes (group II; n = 16). After confirmation of the diabetic status by analysis of the glycemic levels, the maxillary right incisor of each animal was extracted and immersed in milk for 60 min. The root canals of teeth were then instrumented, and were filled with a calcium hydroxide-based dressing and replanted into their sockets. All animals received systemic antibiotic and were killed by anesthetic overdose 10 and 60 days after replantation. The specimens containing the replanted teeth were removed, fixed, decalcified, and embedded in paraffin. Semi-serial 6-mu m-thick sections were obtained and stained with hematoxylin and eosin for histologic and histometric analyses. The results showed that the connective tissue adjacent to the root surface was less organized in the diabetic animals than in the control animals in both periods; the root dentin was less severely affected by root resorption in the diabetic rats; there were no significant differences between the control and diabetic groups regarding the occurrence of replacement resorption and inflammatory resorption.

Repair process of surgical defects filled with autogenous bone grafts in tibiae of diabetic rats

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

Analysis of the healing process in delayed tooth replantation after root canal filling with calcium hydroxide, Sealapex and Endofill: a microscopic study in rats

The major concern in the therapeutics of tooth replantation refers to the occurrence of root resorption and different approaches have been proposed to prevent or treat these complications. The purpose of this study was to evaluate tissue response to delayed replantation of anterior rat teeth treated endodontically using calcium hydroxide, Sealapex, and Endofill without the placement of gutta-percha cones. Thirty rats had their right upper incisor extracted and maintained in dry storage for 60 min. After removal of the dental papilla, enamel organ, pulp tissue, and periodontal ligament remnants, the teeth were immersed in 2% sodium fluoride phosphate acidulated, pH 5.5, for 10 min. The root canals were dried with absorbent paper points and the teeth were assigned to three groups (n = 10) according to the filling material. Group I - calcium hydroxide and propyleneglycol paste, Group II - Sealapex, and Group III - Endofill. The sockets were irrigated with saline and the teeth were replanted. Replacement resorption, inflammatory resorption and ankylosis were observed in all groups. Although the occurrence of inflammatory resorption was less frequent in Group I, there were no statistically significant differences among the groups. It may be concluded that compared to the paste, filling the root canals with Sealapex and Endofill sealers without the placement of gutta-percha cones did not provide better results.

Antimicrobial potential of medicaments used in healing process in dogs' teeth with apical periodontitis

Estudou-se a influência de diferentes irrigantes no potencial antimicrobiano da pasta de hidróxido de cálcio em dentes de cães com periodontite apical. 48 pré-molares de cães adultos tiveram suas câmaras coronárias abertas e expostas à cavidade bucal por 6 meses. Os canais radiculares foram preparados, irrigados e medicados com diferentes substâncias, de acordo com os seguintes grupos: 1) 2,5% NaOCl + CHP; 2) 2% CHX + CHP; 3) vinagre + CHP; 4) vinagre + vinagre. No grupo 4, a solução irrigante e a medicação intracanal utilizada foi o vinagre. Neste grupo, a cada 7 dias, a solução era renovada. Cada amostra foi coletada, mantendo-se o cone de papel esterilizado em posição por 1 min, e a seguir transportado e imerso em 7 mL de Letheen broth, seguido de incubação a 37ºC por 48 h. O crescimento microbiano foi analisado por dois métodos, turbidade do meio de cultura e subcultura em meio nutritivo específico (brain heart infusion). Os resultados mostraram que em todos os grupos experimentais houve crescimento microbiano após 21 dias, em diferentes percentagens: grupo 1 - 30%; grupo 2 - 30%; grupo 3 - 40%; grupo 4 - 60%. Todos os materiais testados apresentaram potencial antimicrobiano. Entretanto, o processo de cura favorecido pela pasta de hidróxido de cálcio não pode ser esquecido, uma vez que muitos estudos já demonstraram sua ação antimicrobiana.

Histomorphometric analysis of the repair process of autogenous bone grafts fixed at rat calvaria with cyanoacrylate

Objective: The purpose of this study was to perform histological and histometric analyses of the repair process of autogenous bone grafts fixed at rat calvaria with ethyl-cyanoacrylate adhesive. Material and Methods: Thirty-two rats were divided into two groups (n=16), Group I - Control and Group II - Adhesive. Osteotomies were made at the right parietal bone for graft obtainment using a 4-mm-diameter trephine drill. Then, the bone segments were fixed with the adhesive in the parietal region of the opposite side to the donor site. After 10 and 30 days, 8 animals of each group were euthanized and the calvarias were laboratorially processed for obtaining hematoxylin and eosin-stained slides for histological and histometric analyses. Results: An intense inflammatory reaction was observed at the 10-day period. At 30 days, this reaction was less intense, despite the presence of adhesive at the recipient-site/graft interface. Graft incorporation to the recipient site was observed only at the control group, which maintained the highest graft size at 10 and 30 days. Conclusions: Although the fragment was stable, the presence of adhesive in Group II did not allow graft incorporation to the recipient site, determining a localized, discrete and persistent inflammatory reaction.

Effect of different dental composite resins on the polymerization process

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

Aldosterone is not Involved in the Ventricular Remodeling Process Induced by Tobacco Smoke Exposure

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

Action of the chemical agent fipronil on the reproductive process of semi-engorged females of the tick Rhipicephalus sanguineus (Latreille, 1806) (Acari: Ixodidae). Ultrastructural evaluation of ovary cells

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

Effects of phonophoresis with Arnica montana onto acute inflammatory process in rat skeletal muscles: An experimental study

This study aimed at verifying the effects of phonophoresis associated with Arnica montana on the acute phase of an inflammatory muscle lesion. Forty Wistar male rats (300 +/- 50 g), of which the Tibialis Anterior muscle was surgically lesioned, were divided into four groups (n = 10 each): control group received no treatment; the ultrasound group (US) was treated in pulsed mode with 1-MHz frequency, 0.5 W/cm(2) intensity (spatial and temporal average - SATA), duty cycle of 1: 2 (2 ms on, 4 ms off, 50%), time of application 3 min per session, one session per day, for 3 days; the phonophoresis or ultrasound plus arnica (US+A) group was treated with arnica with the same US parameters plus arnica gel; and the arnica group (A) was submitted to massage with arnica gel, also for 3 min, once a day, for 3 days. Treatment started 24 h after the surgical lesion. on the 4th day after lesion creation, animals were sacrificed and sections of the lesioned, inflamed muscle were removed for quantitative (mononuclear and polymorphonuclear cell count) and qualitative histological analysis. Collected data from the 4 groups were statistically analyzed and the significance level set at p < 0.05. Results show higher mononuclear cell density in all three treated groups with no significant difference between them, but values were significantly different (p < 0.0001) when compared to control group's. As to polymorphonuclear cell density, significant differences were found between control group (p = 0.0134) and US, US+A and A groups; the arnica group presented lesser density of polymorphonuclear cells when compared (p = 0.0134) to the other groups. No significant difference was found between US and US+A groups. While the massage with arnica gel proved to be an effective anti-inflammatory on acute muscle lesion in topic use, these results point to ineffectiveness of Arnica montana phonophoresis, US having seemingly checked or minimized its anti-inflammatory effect. (C) 2008 Elsevier B. V. All rights reserved.

Healing process after surgical treatment with scalpel, electrocautery and laser radiation: histomorphologic and histomorphometric analysis

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The Cathodic Cleavage of the Nitrobenzoyl Group from Protected Aliphatic Amines in N,N-Dimethylformamide

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

Synthesis of hybrid silicates containing porphyrins incorporated by a sol-gel process and their properties

Porphyrin was incorporated in a silicate network, via a covalent bond, by grafting a functional group with 3-aminopropyltriethoxysilane, using a sol-gel process. We have carried out the synthesis and measured the absorption spectra, nuclear magnetic resonance spectra, infrared (IR) spectra, luminescence spectra and lifetime of these hybrid silicates, porphyrinosilicas. These samples contained the following free-base porphyrins: meso-tetrakis-p-chlorobenzoylporphyrin, meso-tetrakis-2,6-dichloro-3-chlorosulfonylphenylporphyrin. The obtained porphyrinosilicas have similar absorption and luminescence spectra to the free base porphyrins in solution. IR spectra confirm the formation of monomeric species. Lifetime measurement for porphyrinosilica reveals that 32% +/- 2% of porphyrin is covalently bonded to the silica network. (C) 1999 Elsevier B.V. B.V. All rights reserved.

THE CATHODIC CLEAVAGE OF THE NITROBENZENESULFONYL GROUP FROM ALIPHATIC-AMINES IN N,N-DIMETHYLFORMAMIDE

The reduction of benzenesulfonyl derivatives of n-butylamine and N,N-di-n-butylamine with nitro substituents at the 2, 3 and 4 positions of the phenyl ring in N,N-dimethylformamide is reported. The N,N-di-n-butyl-4- and N-n-butyl-2-nitrobenzenesulfonamides are reduced in two cathodic steps. The first one, at about -0.90 V vs. SCE, a reversible one-electron process, gives a stable anion radical. The second reduction step at -1.70 V vs. SCE leads to cleavage of the S-N bond in good yields (> 70%). It is shown that the reduction of the N-n-butyl-3- and N-n-butyl-4-nitrobenzenesulfonamide is different, with three reduction steps. The first reduction step occurs with the formation of an unstable anion radical, which decomposes via N-H bond cleavage. The reduction of this sulfonamide anion occurs at -1.16 V vs. SCE and the third cathodic step arises at -1.70 V vs. SCE when the remaining radical anion is reduced to its dianion. The S-N bond cleavage is rapid but is always a minor process. The mechanisms of the reduction are discussed.