Poda apical, densidade de plantas e cobertura plástica do solo na produtividade do tomateiro em cultivo protegido

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

Effect of amniotic membrane transplantation on corneal healing and proteoglycan expression in an experimental model of limbal deficiency in rabbits

PURPOSE. Amniotic membrane transplantation (AMT) has been used as a graft or as a dressing in ocular surface reconstruction, facilitating epithelization, maintaining normal epithelial phenotype, and reducing inflammation, vascularization, and scarring. The corneal transparency is due, at least in part, to the arrangement in orthogonal lamellae of collagen fibrils, surrounded by proteoglycans (PGs). These PGs regulate fibrilogenesis, the matrix assembly, and ultimately the corneal transparency. The purpose of the present study was to investigate the effects of AMT upon the corneal PGs after severe limbal injury.METHODS. Experiments were performed on the right corneas of 22 New Zealand female albino rabbits, and their left corneas were used as matched controls. These animals were divided into 3 groups: G1 (n = 10): total peritomy and keratolimbectomy, followed by application of 0.5 M NaOH; G2 (n = 10): submitted to the same trauma as G1, and treated by AMT; G3: no trauma, only AMT (n = 2). The right corneas of G2 and G3 were covered by DMSO 4 cryopreserved human amniotic membrane, fixed by interrupted 9-0 mononylon sutures, with its stromal face toward the ocular surface. After 7 or 30 days, the corneas were removed and PGs were extracted.RESULTS. Normal corneas contained approximately 9 mg of PGs per gram of dry tissue. AMT on intact cornea (G3) did not cause any changes in the concentration of PGs. In contrast, injured corneas contained much less PGs, both on the seventh and on the 30th day posttrauma. The PG concentration was even lower in injured corneas treated by AMT. This decrease was due almost exclusively to dermatan sulfate PGs, and the structure of dermatan sulfate was also modified, indicating changes in the biosynthesis patterns.CONCLUSIONS. Although beneficial effects have been observed on clinical observation and concentration of soluble proteins after AMT, the normal PG composition of cornea was not attained, even 30 days postinjury, indicating that the normal ocular surface reconstruction, if possible, is a long-term process. (Eur J Ophthalmol 2010; 20: 290-9)

Análise radiográfica computadorizada da reabsorção radicular apical após a utilização de duas mecânicas ortodônticas

OBJETIVO: a reabsorção radicular apical é uma condição comumente observada durante e após o tratamento ortodôntico e fatores como tipo de aparelhagem ortodôntica utilizada, magnitude das forças aplicadas e duração do tratamento podem estar relacionados ao processo de arredondamento do ápice radicular. Buscou-se avaliar, por meio de imagens radiográficas computadorizadas, a quantidade de reabsorção no ápice radicular, quando da utilização de duas diferentes técnicas de mecânica ortodôntica fixa: Edgewise com acessórios padrão e Edgewise com acessórios totalmente programados. METODOLOGIA: a amostra constituiu-se de 20 pacientes tratados pelo mesmo profissional na Clínica de Ortodontia da Faculdade de Odontologia de Araçatuba - UNESP. Os pacientes foram divididos em dois grupos: grupo 1 (Tratados com Edgewise com acessórios padrão e fios de aço) e grupo 2 (Tratados com Edgewise com acessórios totalmente programados e fios de níquel-titânio). A avaliação radiográfica digital foi realizada por um único operador por meio de exposições radiográficas digitais feitas no início do tratamento ortodôntico, após retração de caninos e final de tratamento, utilizando o sistema de escores proposto por Levander e Malmgren (1988). RESULTADOS E CONCLUSÕES: a análise dos escores permitiu concluir que o tratamento ortodôntico empregando a técnica Edgewise com acessórios totalmente programados e fios de níquel-titânio apresentou menores graus de reabsorção radicular apical, em comparação à técnica Edgewise com acessórios padrão e fios de aço. Observou-se que, independentemente da técnica empregada, o tratamento ortodôntico como um todo apresentou um grau moderado de reabsorção radicular apical.

Influence of the type of vehicle and limit of obturation on apical and periapical tissue response in dogs' teeth after root canal filling with mineral trioxide aggregate

The purpose of this study was to investigate the influence of the type of vehicle (distilled water or propyleneglycol) on the response of apical tissues of dogs' teeth after root canal filling with mineral trioxide aggregate (MTA) at two different limits. Forty roots of incisors and premolars of two adult dogs were used. After pulpectomy, the root canals were prepared biomechanically, and the roots had the apical cemental barrier penetrated with a #15 K-file and widened to a #25 K-file. The root canals were assigned to four groups according to the vehicle used for MTA (ProRoot-MTA; Tulsa Dental, Tulsa, OK) preparation and the limit of root canal filling: group 1, filling with MTA/distilled water to the limit of the cemental canal; group 2, overfilling with MTA/distilled water, group 3, filling with MTA/propyleneglycol to the limit of the cemental canal; and group 4, overfilling with MTAlpropyleneglycol. The animals were killed by anesthetic overdose 90 days after endodontic treatment and the anatomic pieces were prepared for histomorphological analysis. The sections were stained with hematoxylin and eosin and Brown and Brenn techniques. The results showed that MTA pastes prepared with either distilled water or propyleneglycol as vehicles had similar biological behavior (p > 0.05); root fillings placed at the cemental canal limit showed better results than the overfillings (p = 0.01), and MTA/propyleneglycol paste was more easily placed into the root canals than MTA/distilled water paste.

Influence of apical patency and filling material on healing process of dogs' teeth with vital pulp after root canal therapy

Foi propósito deste trabalho observar o processo de reparo de dentes de cães após obturação dos canais com dois cimentos diferentes, fazendo ou não a patência apical. Após uma sobreinstrumentação, os canais receberam um curativo de uma solução de corticosteróide-antibiótico por 7 dias, com o objetivo de obter invaginação de tecido conjuntivo para dentro dos canais. Após esse período, esse tecido foi totalmente removido em metade dos casos (grupos com patência apical) e preservados no restante dos casos (grupos sem patência apical). Os canais foram obturados pela técnica da condensação lateral empregando um cimento a base de hidróxido de cálcio (Sealer Plus) ou um cimento de Grossman (Fill Canal). Os animais foram sacrificados por overdose anestésica 60 dias após o tratamento endodôntico e as peças anatômicas foram obtidas e preparadas para análise histológica. Os dados obtidos foram analisados com base em diversos parâmetros histomorfológicos. Os resultados foram melhores nos grupos sem patência apical (p=0,01) do que nos grupos com patência. Dentre os cimentos estudados, os melhores resultados foram observados com o cimento Sealer Plus (p=0,01). em conclusão, tanto a patência apical (presença ou ausência) quanto o tipo de material obturador de canal influíram no processo de reparo apical de dentes de cães com polpas vitais após tratamento endodôntico. O emprego de um cimento a base de hidróxido de cálcio em dentes sem patência apical promoveu os melhores resultados, dentre as condições experimentais propostas.

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.

Tissue reaction to Endométhasone sealer in root canal fillings short of or beyond the apical foramen

Objective: This study evaluated the response of periapical tissues to the endodontic sealer Endomethasone in root canal fillings short of or beyond the apical foramen. Material and Methods: Twenty root canals of premolars and incisors of 2 mongrel dogs were used. After coronal access and pulp extirpation, the canals were instrumented up to a size 55 K-file and the apical cemental barrier was penetrated with a size 15 K-file to obtain a main apical foramen, which was widened to a size 25 K-file. The canals were irrigated with saline at each change of file. The root canals were obturated either short of or beyond the apical foramen by the lateral condensation of gutta-percha and Endomethasone, originating 2 experimental groups: G1: Endomethasone/short of the apical foramen; G2: Endomethasone/beyond the apical foramen. The animals were killed by anesthetic overdose 90 days after endodontic treatment. The individual roots were obtained and serial histological sections were prepared for histomorphological analysis (H&E and Brown & Brenn techniques) under light microscopy. The following parameters were examined: closure of the apical foramen of the main root canal and apical opening of accessory canals, apical cementum resorption, intensity of the inflammatory infiltrate, presence of giant cells and thickness and organization of the apical periodontal ligament. Each parameter was scored 1 to 4, 1 being the best result and 4 the worst. Data were analyzed statistically by the Wilcoxon nonparametric tests (p=0.05). Results: Comparing the 2 groups, the best result (p<0.05) was obtained with root canal filling with Endomethasone short of the apical foramen but a chronic inflammatory infiltrate was present in all specimens. Conclusions: Limiting the filling material to the root canal space apically is important to determine the best treatment outcome when Endomethasone is used as sealer.

Influence of apical foramen widening and sealer on the healing of chronic periapical lesions induced in dogs' teeth

Objective. The aim of this study was to evaluate the influence of apical foramen widening on the healing of chronic periapical lesions in dogs' teeth after root canal filling with Sealer 26 or Endomethasone.Study design. Forty root canals of dogs' teeth were used. After pulp extirpation, the canals were exposed to the oral cavity for 180 days for induction of periapical lesions, and then instrumented up to a size 55 K-file at the apical cemental barrier. In 20 roots, the cemental canal was penetrated and widened up to a size 25 K-file; in the other 20 roots, the cemental canal was preserved (no apical foramen widening). All canals received a calcium hydroxide intracanal dressing for 21 days and were filled with gutta-percha and 1 of the 2 sealers: group 1: Sealer 26/apical foramen widening; group 2: Sealer 26/no apical foramen widening; group 3: Endomethasone/apical foramen widening; group 4: Endomethasone/no apical foramen widening. The animals were killed after 180 days, and serial histologic sections from the roots were prepared for histomorphologic analysis. Scores were assigned according to preestablished histomorphologic parameters and analyzed statistically by Kruskal-Wallis and Mann-Whitney U tests.Results. Regarding new cementum formation, repair of cementum and bone resorption areas, presence of microorganisms, inflammatory cell infiltrate and periodontal ligament conditions, significantly better periapical healing was obtained when foramen widening was done and Sealer 26 was used.Conclusion. Apical foramen widening and calcium hydroxide-containing sealer were more favorable to the healing of chronic periapical lesions. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:932-940)

Tissue reaction of the EndoREZ in root canal fillings short of or beyond an apical foramenlike communication

This study evaluated the response of periapical tissues to the endodontic sealer EndoREZ in root canal fillings short of or beyond the apical foramenlike communication. Twenty root canals of premolars and incisors of 2 mongrel dogs were used. After coronal access and pulp extirpation, the canals were instrumented up to a size 55 K-file and the apical cemental barrier was penetrated with a size 15 K-file to create an apical foramenlike communication, which was widened to a size 25 K-file. The canals were irrigated with saline at each change of file. The root canals were obturated either short of or beyond the apical foramenlike opening by the lateral condensation of gutta-percha and EndoREZ, originating 2 experimental groups: G1, EndoREZ/short of the apical foramenlike opening, and G2, EndoREZ/beyond the apical foramenlike opening. The animals were killed by anesthetic overdose 90 days after endodontic treatment. The individual roots were obtained and serial histological sections were prepared for histomorphological analysis (H&E and Brown and Brenn techniques) under light microscopy. The following parameters were examined: closure of the apical foramenlike communication and apical opening of accessory canals, apical cementum resorptions, intensity of the inflammatory infiltrate, presence of giant cells, and thickness and organization of the apical periodontal ligament. Each parameter was scored 1 to 4, 1 being the best result and 4 the worst. Data were analyzed statistically by the Wilcoxon nonparametric tests (P = .05). Comparing the 2 groups, the best result (P = .05) was obtained with root canal filling with EndoREZ short of the apical foramenlike opening. In conclusion, limiting the filling material to the root canal space apically was important to determine the best treatment outcome when EndoREZ was used as the sealer. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010; 109: e94-e99)

Evaluation of the apical infiltration after root canal disruption and obturation

The aim of this study was to evaluate two root canal filling techniques used in teeth that had their apical foramen disrupted and compare the apical infiltration with an ideal clinical situation. Twenty-seven freshly extracted single-rooted teeth were selected and radiographed to confirm the existence of a single and straight root canal. The crowns were removed at a mean distance of 11 mm from the apex. The teeth had the root canals instrumented and were randomly assigned to 3 groups (n=9): ND group-root canals were filled using the lateral compaction technique and no disruption was performed; DRF group-the apical constriction was disrupted by advancing a #40 K-file 1 mm beyond the original working length, the canals were reinstrumented to create an apical ledge at 1 mm from the apical foramen and were obturated with a master gutta-percha cone with same size as the last file used for reinstrumentation; DF group - the teeth had the apical constriction disrupted and the canals were obturated with a master gutta-percha cone that fit at 1 mm from the apex. The teeth were submitted to dye leakage test with Rhodamine B for 7 days, using vaccum on the initial 5 min. The teeth were sectioned longitudinally and the leakage was measured in a linear fashion from apex to crown. There was no statistically significant difference (p>0.05) between the groups that had the apical foramen disrupted (DF, DRF), but significant difference was found between the disrupted groups and the non-disrupted one (p<0.01). In conclusion, none of the evaluated techniques was able to prevent apical infiltration, so working length so the working length determination has to be established and maintained carefully.

Bone healing in critical-size defects treated with either bone graft, membrane, or a combination of both materials: a histological and histometric study in rat tibiae

Objectives: The aim of the present investigation was to histologically analyze the effect of using lyophilized bovine bone (GenOx (R) organic matrix) with (or without) guided tissue regeneration (using a decalcified cortical osseous membrane [GenDerm (R)]) on bone healing in surgically created critical-size defects created in rat tibia.Material and methods: Surgical critical-size bone defects were created in 64 animals that were randomly divided into four groups: group I (control); group II (defect filled with GenOx (R)); group III (defect covered by GenDerm (R)); group IV (defect filled with GenOx (R) and covered by GenDerm (R)). Animals were killed at 30 or 90 days post-surgery. The specimens were embedded in paraffin, serially cut, and stained with hematoxylin and eosin for analysis under light microscopy. The formation of new bone in the cortical area of the defect was histomorphometrically evaluated.Results: All experimental groups demonstrated superior bone healing compared with the control group. However, group IV samples showed evidence of more advanced healing at both 30 and 90 days post-surgery as compared with the other experimental groups.Conclusions: The bovine organic bone graft GenOx (R) associated with GenDerm (R) this produced the best treatment results in the case of critical-size defects in rat tibia.

Use of bovine bone graft and bone membrane in defects surgically created in the cranial vault of rabbits. Histologic comparative analysis

Purpose: This study was proposed to analyze histologically the process of repairing bone defects created surgically in the cranial vaults of rabbits. Materials and Methods: Thirty adult male rabbits (Oryctolagus cunilicus) received, under general anesthesia, bilateral parietal osteotomies by means of a 6mm-diameter trephine. The bony defects were divided into 4 groups. In group 1 the defect did not receive any treatment; in group 2 the defect was filled with lyophilized bovine bone (Biograft); in group 3 it was filled with bovine bone and covered with a bone matrix membrane (Bioplate); in group 4 it was covered with a bone matrix membrane. Animals were sacrificed in 3 equal groups at 15, 30, and 60 days. The specimens were subjected to routine laboratory procedures to evaluate the degree of bone repair. Results: After 60 days, new bone formation in group 2 was not satisfactory when compared to that of group 3. Large amounts of new bone formation in maturation were seen in group 3. In the defects covered with a membrane the results were similar to those of group 1 (ie, the cavity was filled with fibrous connective tissue). The implanted bone and membranes were totally resorbed. Discussion and Conclusions: the use of a membrane served as a barrier against the migration of cells from the adjacent tissue and the bone graft/membrane preserved the cavity space, resulting in an enhanced osteogenic effect.

Apical Sealing Quality of In Vitro Apicectomy Procedures After Using Both Er:YAG and Nd:YAG

The aim of this study was to evaluate the apical sealing of dentinal tubules after root-end surface cutting by using Er:YAG and Nd:YAG lasers. After root-canal instrumentation and filling, apices of 50 extracted maxillary canine human teeth were resected by Er: YAG with 400 mJ, 10 Hz, for 30 sec. The samples were randomly assigned to five groups (n = 10): (GI) treated without root-end cavity, but with Nd: YAG (1.0W, 10 Hz, 20 sec) for dentinal tubules sealing; (GII) treated with root-end cavity without the use of Nd: YAG; (GIII) treated with root-end cavity and Nd: YAG application; (GIV) treated with root-end cavity made by Er: YAG with no focus and without Nd: YAG application; and (GV) treated without root-end cavity and without Nd: YAG application. The root-end cavities were performed by using Er: YAG at 300 mJ, 10 Hz, for 20 sec. Subsequently, all teeth were waterproofed and immersed in 2% methylene blue for 48 h in a vacuum environment. The samples were longitudinally sectioned, and microleakage was measured. ANOVA and the Fisher LSD test showed that GIV was less susceptible to microleakage than were the other groups (p < 0.05). Interestingly, the use of the Er: YAG with no focus showed superior dentinal tubule sealing in comparison with the other groups, even with or without root-end cavity and Nd: YAG application.

Differentiation of epithelial cells in the urinary tract

Uroplakins, cytokeratins and the apical plasma membrane were studied in the epithelia of mouse urinary tract. In the simple epithelium covering the inner medulla of the renal pelvis, no uroplakins or cytokeratin 20 were detected and cells had microvilli on their apical surface. The epithelium covering the inner band of the outer medulla became pseudostratified, with the upper layer consisting of large cells with stalks connecting them to the basal lamina. Uroplakins and cytokeratin 20 were not expressed in these cells. However, some superficial cells appeared without connections to the basal lamina; these cells expressed uroplakins Ia, Ib, II and III and cytokeratin 20, they contained sparse small uroplakin-positive cytoplasmic vesicles and their apical surface showed both microvilli and ridges. Cytokeratin 20 was seen as dots in the cytoplasm. This epithelium therefore showed partial urothelial differentiation. The epithelium covering the outer band of the outer medulla gradually changed from a two-layered to a three-layered urothelium with typical umbrella cells that contained all four uroplakins. Cytokeratin 20 was organized into a complex network. The epithelium possessed an asymmetric unit membrane at the apical cell surface and fusiform vesicles. Umbrella cells were also observed in the ureter and urinary bladder. In males and females, the urothelium ended in the bladder neck and was continued by a non-keratinized stratified epithelium in the urethra in which no urothelial cell differentiation markers were detected. We thus show here the expression, distribution and organization of specific proteins associated with the various cell types in the urinary tract epithelium.