Concepto de blindaje endodóntico: consideraciones restauradoras en Endodoncia

El enfoque integrado de los procedimientos endodónticos y restauradores del elemento dental permite la reincorporación del mismo tratado endodónticamente, a su función en el sistema estomatognático. El diente despulpado se debilita debido a los cambios que ocurren en su estructura, porque se entiende que una modificación en su arquitectura y morfología, puede volverlo más friable debido a la gran pérdida de estructura dental por caries, preparación y extensión de la cavidad. De este modo, el blindaje radicular y coronario busca recuperar la resistencia estructural del diente tratado endodónticamente

Análise da contaminação em cones endodônticos de papel absorvente

PURPOSE: The aim of this study was to assess the contamination status of endodontic absorbent paper points from sterilized or not sterilized commercial packs, as well as paper points exposed to the dental office environment. METHODS: Twenty absorbent paper points were evaluated for contamination status packed under different conditions: commercial/sterilized pack, commercial/non-sterilized pack, exposed to the clinical environment, and intentionally contaminated (positive control). Contamination was determined qualitatively and quantitatively by aerobiosis, capnophilic growth, and pour plate. The Petri dishes were analyzed with a colony counter, and the results were expressed as colony-forming units. The data were analyzed by Kruskal-Wallis test (α=0.05). RESULTS: No difference in colony-forming units was found among the groups of endodontic absorbent paper points. All groups were contaminated by fungi and bacteria. CONCLUSION: It can be concluded that the sterilization of absorbent endodontic paper points before clinical use should be recommended regardless of commercial presentationOBJETIVO: Este estudo avaliou a contaminação de cones de papel absorventes não esterilizados e esterilizados e selados em embalagens, e outros expostos ao ambiente de consultório odontológico. METODOLOGIA: Vinte cones de papel sob diferentes condições foram testados para verificar a contaminação: comercialmente esterilizados, comercialmente não esterilizados, expostos ao ambiente clínico, e intencionalmente contaminados. A contaminação foi determinada qualitativamente e quantativamente por diferentes condições: aerobiose, crescimento capnofílico ou pour plate. As placas Petri cultivadas com o cone foram analizadas através de contagem de colônias, e os resultados expressos em unidade formadora de colônias. Os dados foram analisados por teste de Kruskal-Wallis (α>0,05). RESULTADOS: Não houve diferença estatística significante entre os grupos, sendo que todos cones de papel endodôntico estavam contaminados por bactérias e fungos. CONCLUSÃO: Concluiu-se que a esterilização de cones de papel endodônticos deve ser recomendada antes do uso clínico independente de sua apresentação comercial

Immunohistological study of the effect of vascular Endothelial Growth Factor on the angiogenesis of mature root canals in rat molars

Tissue bioengineering has been applied to Endodontics to seek a more biological treatment. The presence of blood vessels is crucial for cell nutrition during tissue formation. Objective: This study analysed the application of vascular endothelial growth factor (VEGF) in the angiogenesis of mature root canals. Material and methods: Upper first molars of twelve 13-week old Wistar male rats were used. The root pulp of the mesiobuccal canal was removed and the root canal instrumented with K-files up to size #25. Periapical bleeding was induced into the root canal by introducing a #15 K-file beyond the apex. The teeth on the right side of the arch were filled up with blood clot (G1), whereas those on the left side were filled up with blood clot plus 50 ng/ml of VEGF (G2). Teeth were sealed with light-curing glass-ionomer cement and the animals were sacrificed after 60 days. The maxilla was dissected and fixed before obtaining serial sections for histological processing with haematoxylin-eosin (HE) and immunohistochemical factor-VIII. Immunohistochemical labelling was evaluated using scores for statistical analysis. Results: Immunohistological analysis demonstrated the presence of angiogenesis in both groups, but with higher angiogenic maturation in G2 during the experimental period (p<0.05). HE staining showed connective tissue with absence of odontoblasts in all specimens. Conclusions: It can be concluded that it is possible to obtain angiogenesis in mature root canals with or without the use of VEGF, although the latter tends to accelerate blood vessel formation

Repair of critical-size defects with autogenous periosteum-derived cells combined with bovine anorganic apatite/collagen: an experimental study in rat calvaria

The aim of this study was to evaluate the bone repair using autogenous periosteum-derived cells (PDC) and bovine anorganic apatite and collagen (HA-COL). PDC from Wistar rats (n=10) were seeded on HA-COL discs and subjected to osteoinduction during 6 days. Critical-size defects in rat calvarias were treated with blood clot (G1), autogenous bone (G2), HA-COL (G3) and HA-COL combined with PDC (G4) (n=40), and then analyzed 1 and 3 months after surgeries. Radiographic analysis exhibited no significant temporal change. G1 and G2 had discrete new marginal bone, but the radiopacity of graft materials in G2, G3 and G4 impaired the detection of osteogenesis. At 3 months, histopathological analysis showed the presence of ossification islets in G1, which was more evident in G2, homogeneous new bone around HA-COL in G3 and heterogeneous new bone around HA-COL in G4 in addition to moderate presence of foreign body cells in G3 and G4. Histomorphometric analysis showed no change in the volume density of xenograft (p&gt;0.05) and bone volume density in G2 was twice greater than in G1 and G4 after 3 months (p<0.05), but similar to G3. The PDC did not increase bone formation in vivo, although the biomaterial alone showed biocompatibility and osteoconduction capacity.O objetivo deste estudo foi avaliar o reparo ósseo usando células derivadas de periósteo (PDC) e apatita inorgânica e colágeno bovinos (HA-COL). PDC de ratos Wistar (n=10) foram semeadas sobre discos de HA-COL e osteoinduzidas por 6 dias. Defeitos de tamanho crítico em calvárias de ratos foram tratados com coágulo sanguíneo (G1), osso autógeno (G2), HA-COL (G3) ou HA-COL associado a PDC (G4) (n=40) e analisados em 1 e 3 meses após as cirurgias. Análise radiográfica não exibiu mudança temporal significante, G1 e G2 tiveram aumento discreto de novo osso marginal, entretanto a radiopacidade dos materiais de enxerto em G2, G3 e G4 prejudicou a detecção de osteogênese. Análise histopatológica mostrou em 3 meses ilhotas de ossificação em G1 que foi maior em G2, novo osso homogêneo ao redor de HA-COL em G3 e novo osso heterogêneo ao redor de HA-COL em G4 além da presença moderada de células gigantes de corpo estranho em G3 e G4. Análise histomorfométrica mostrou a densidade de volume inalterada do xenoenxerto (p&gt;0,05) e a densidade de volume de novo osso em G2 duas vezes maior que G1 e G4 após 3 meses (p<0,05), mas similar a G3. PDC não aumentaram a formação óssea in vivo apesar do biomaterial sozinho ter apresentado biocompatibilidade e capacidade osteocondutora

Resposta inflamatória tecidual da implantação de hidróxido de cálcio e iodofórmio em dorso de ratos

PURPOSE: This study evaluated the inflammatory reaction caused by the implantation of iodoform and calcium hydroxide in the back of rats. These drugs may be used as intracanal dressings to eliminate residual bacteria of the root canal system. METHODS: Twenty albinic rats (Rattus norvegicus, var Wistar) were divided into four groups: control group 1 (CG1) had normal skin; control group 2 (CG2) had wounded tissue without drugs; in groups 3 and 4, iodoform (IG) and calcium hydroxide (CHG) were inserted into the wounds, respectively. After 3, 5 and 11 days, slices of the implanted areas were macroscopically and microscopically observed regarding to their qualitative and quantitative aspects. RESULTS: In the macroscopical analysis, the CHG showed a large area of necrosis and swelling, which progressively decreased; in the IG the presence of iodoform surrounded by normal tissue was observed. The qualitative and quantitative histological analysis showed that IG promoted a shorter delay in the inflammatory response than the CHG. CONCLUSION: The inflammatory reaction for iodoform had a peak period five days after the drug insertion. By comparison, calcium hydroxide showed a very large area of necrosis that could only be partially eliminated after eleven days.OBJETIVO: O objetivo deste estudo foi avaliar a resposta inflamatória causada pela implantação do iodofórmio ou hidróxido de cálcio em dorso de ratos. Estas drogas podem ser usadas como curativo intracanal para eliminar bactérias residuais do sistema de canal radicular. METODOLOGIA: Foram utilizados 20 ratos albinos (Rattus norvegicus, var Wistar) e divididos em 4 grupos: grupo controle 1 (CG1) representado por tecido normal íntegro; grupo controle 2 (CG2) com ferida e sem medicação; nos grupos 3 e 4, Iodofórmio (IG) e hidróxido de cálcio (CHG) foram, respectivamente, inseridos nas feridas. Após três, cinco e onze dias, cortes microscópicos das áreas implantadas foram observados macroscópica e microscopicamente quanto a seus aspectos qualitativos e quantitativos. RESULTADOS: Na análise macroscópica, o CHG mostrou uma grande área de necrose e edema, o que diminuiu progressivamente, no GI, a presença de iodofórmio rodeada por tecido normal foi observado. A análise qualitativa e quantitativa histológica mostrou que IG promoveu um prazo mais curto na resposta inflamatória do que o CHG. CONCLUSÃO: A reação inflamatória de iodofórmio teve um período de pico de cinco dias após a inserção de drogas. Em comparação, o hidróxido de cálcio mostrou uma grande área de necrose que só poderia ser parcialmente eliminada após onze dias

Evaluation of the WaveOne Gold and One Shape New Generation in Reducing Enterococcus faecalis from Root Canal

The aim of this study was to evaluate the WaveOne Gold and One Shape New Generation systems regarding the bacterial removal from root canals infected with Enterococcus faecalis by comparing them to the conventional WaveOne and One Shape systems. Forty-eight distobuccal root canals of maxillary molars sterilized with ethylene oxide were infected with E. faecalis for 21 days, and then root canal initial bacterial sample was collected with paper cones and plated on M-enterococcus agar. The specimens were randomly divided into 4 groups according to the instrumentation: WaveOne Gold, One Shape New Generation, WaveOne and One Shape. After instrumentation, samples were collected with use of scraping and paper cones at immediate and 7 days after instrumentation. The bacterial reduction was calculated and then made intragroup analysis by Friedman test and intergroup analysis by Kruskal-Wallis with Dunn's post-hoc test, all at 5% significance. All techniques significantly reduced the number of bacteria in the root canal (p0.05). Novel single-file systems promote better bacterial removal than the conventional single-file systems

Dental Pulp Vascular Permeability Changes Induced by Dental Bleaching

Aiming to compare the effect of different light sources for dental bleaching on vascular permeability of dental pulps, forty-eight incisors were used. The bleaching agent (35% hydrogen peroxide) was activated by halogen light; LED (Light Emitting Diode) or LED, followed by laser phototherapy (LPT) (lambda = 780 nm; 3 J/cm(2)). After the bleaching procedures, the animals received an intra-arterial dye injection and one hour later were sacrificed. The teeth were diaphanized and photographed. The amount of blue stain content of each dental pulp was quantified using a computer imaging program. The data was statistically compared (p &lt;= 0.05). The results showed a significant higher (p &lt;= 0.01) dye content in the groups bleached with halogen light, compared with the control, LED and LED plus LPT groups. Thus, tooth bleaching activated by LED or LED plus LPT induces lesser resulted in increased vascular permeability than halogen light