RESUMO
OBJECTIVES: The objective of the present work was to evaluate the ultrasonic agitation, time and vehicle (propylene glycol or distilled water) on the antimicrobial potential and penetrability of calcium hydroxide pastes on infected dentin by means of Confocal Laser Scanning Microscopy (CLSM) and microbiological culture (MC). MATERIALS AND METHODS: Dentin specimens were infected with Enterococcus faecalis using a new contamination protocol of 5 days. The specimens were divided into eight groups and dressed with the pastes for 7 or 15 days: G1) calcium hydroxide (CH) + propylene glycol (prop)/7 days (d), G2) CH + prop/7d + ultrasonic agitation (U), G3) CH + distilled water (dw)/7d, G4) CH + dw/7d + U, G5) CH + prop/15d, G6) CH + prop/15d + U, G7) CH + dw/15d, G8) CH + dw/15d + U. The ultrasonic activation was made for 1 min in both directions with a plain point insert. After medications removal, the images obtained by CLSM showed the viable (green) and dead (red) bacteria with Live and Dead dye. By the MC, the dentinal wall debris obtained by burs were collected for colony counts. For the penetration test, the Rodamine B dye was added to the CH pastes and analyzed by CLSM. RESULTS: The 7 and 15-days CH + prop+U pastes performed better antimicrobial efficacy, followed by the CH + dw+U/15d paste. CONCLUSIONS: All pastes demonstrated better penetration and antimicrobial activity against E. faecalis when agitated with ultrasound, even in periods of up to seven days. The propylene glycol vehicle showed better results. CLINICAL RELEVANCE: Agitation of the dressing that remains for less time inside the root canal can optimize the decontamination of endodontic treatment.
Assuntos
Hidróxido de Cálcio/farmacologia , Dente , Terapia por Ultrassom/efeitos adversos , Animais , Anti-Infecciosos/farmacologia , Hidróxido de Cálcio/farmacocinética , Bovinos , Cimentos Dentários/farmacocinética , Cimentos Dentários/farmacologia , Cavidade Pulpar/efeitos dos fármacos , Cavidade Pulpar/microbiologia , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Materiais Restauradores do Canal Radicular/farmacocinética , Materiais Restauradores do Canal Radicular/farmacologia , Irrigantes do Canal Radicular/farmacocinética , Fatores de Tempo , Dente/efeitos dos fármacos , Dente/metabolismo , Dente/microbiologia , Permeabilidade Dentária/efeitos dos fármacos , Ultrassom/métodosRESUMO
Archaeological research documents major technological shifts among people who have lived in the southern tip of South America (South Patagonia) during the last thirteen millennia, including the development of marine-based economies and changes in tools and raw materials. It has been proposed that movements of people spreading culture and technology propelled some of these shifts, but these hypotheses have not been tested with ancient DNA. Here we report genome-wide data from 20 ancient individuals, and co-analyze it with previously reported data. We reveal that immigration does not explain the appearance of marine adaptations in South Patagonia. We describe partial genetic continuity since ~6600 BP and two later gene flows correlated with technological changes: one between 4700-2000 BP that affected primarily marine-based groups, and a later one impacting all <2000 BP groups. From ~2200-1200 BP, mixture among neighbors resulted in a cline correlated to geographic ordering along the coast.
Assuntos
DNA Antigo/análise , Fósseis , Fluxo Gênico , Genoma Humano/genética , Migração Humana , Arqueologia/métodos , Argentina , Osso e Ossos/metabolismo , Chile , DNA Mitocondrial/classificação , DNA Mitocondrial/genética , Variação Genética , Geografia , Humanos , Filogenia , Datação Radiométrica/métodos , Análise de Sequência de DNA/métodos , Dente/metabolismoRESUMO
Dental phenotypic data are often used to reconstruct biological relatedness among past human groups. Teeth are an important data source because they are generally well preserved in the archaeological and fossil record, even when associated skeletal and DNA preservation is poor. Furthermore, tooth form is considered to be highly heritable and selectively neutral; thus, teeth are assumed to be an excellent proxy for neutral genetic data when none are available. However, to our knowledge, no study to date has systematically tested the assumption of genetic neutrality of dental morphological features on a global scale. Therefore, for the first time, this study quantifies the correlation of biological affinities between worldwide modern human populations, derived independently from dental phenotypes and neutral genetic markers. We show that population relationship measures based on dental morphology are significantly correlated with those based on neutral genetic data (on average r = 0.574, p < 0.001). This relatively strong correlation validates tooth form as a proxy for neutral genomic markers. Nonetheless, we suggest caution in reconstructions of population affinities based on dental data alone because only part of the dental morphological variation among populations can be explained in terms of neutral genetic differences.
Assuntos
Fenótipo , Polimorfismo de Nucleotídeo Único , Característica Quantitativa Herdável , Dente/metabolismo , África , Antropologia Física/métodos , Ásia , Austrália , Bases de Dados Genéticas , Conjuntos de Dados como Assunto , Europa (Continente) , Feminino , Fósseis , Marcadores Genéticos , Humanos , Masculino , Odontometria , América do Sul , Sequências de Repetição em Tandem , Dente/anatomia & histologiaRESUMO
New techniques for tissue engineering (TE) are rapidly emerging. The basic concept of autologous TE is to isolate cells from small biopsy specimens, and to expand these cells in culture for subsequent seeding onto biodegradable scaffolds. Nanocrystalline diamond films have attracted the attention of researchers from a variety of different areas in recent years, due to their unique and exceptional properties. In this approach, human dental stem cells (hDSCs) were characterized by flow cytometry and grown on diamond films with hydrogen (H)-terminated and oxygen (O)-terminated surfaces for 28 days, and then removed by lysis and washing with distilled water. Energy dispersive spectroscopy analysis was performed, showing that the regions with O-terminated surfaces contained much higher levels of deposited calcium, oxygen, and phosphorus. These results suggest that the extracellular matrix was considerably more developed in the O-terminated regions, as compared with the H-terminated regions. In addition, optical microscopy of hDSCs cultured on the diamond substrate with H- and O-terminated surfaces, before washing with distilled water, showed preferential directions of the cells arrangement, where orthogonal lines suggest that the cells appeared to be following the O-terminated regions or hydrophilic surface. These findings suggest that O-terminated diamond surfaces prepared on biodegradable scaffolds can be useful for mineralized dental tissue formation.
Assuntos
Nanodiamantes/química , Células-Tronco/citologia , Engenharia Tecidual , Alicerces Teciduais/química , Dente/citologia , Células Cultivadas , Humanos , Interações Hidrofóbicas e Hidrofílicas , Células-Tronco/metabolismo , Dente/metabolismoRESUMO
The aim of this study was to evaluate the strontium incorporation into specific bones and teeth of rats treated with strontium ranelate. The relative strontium levels [Sr/(Ca + Sr) ratio] were obtained by synchrotron radiation micro X-ray fluorescence. The incisor teeth were further examined by energy dispersive X-ray spectroscopy (EDS) in a scanning electron microscope. The isolated mineral phase was investigated by EDS in a transmission electron microscope and X-ray diffraction. The strontium content was markedly increased in animals treated with strontium ranelate, with different incorporation levels found among specific bones, regions within the same bone and teeth. The highest strontium levels were observed in the iliac crest, mandible and calvaria, while the lowest were observed in the femoral diaphysis, lumbar vertebrae, rib and alveolar bone. The strontium content was higher in the femoral neck than in the diaphysis. The strontium levels also varied within the alveolar bone. High levels of strontium were found in the incisor tooth, with values similar to those in the iliac crest. Strontium was observed in both enamel and dentin. The strontium content of the molar tooth was negligible. Strontium was incorporated into the mineral substance, with up to one strontium replacing one out of 10 calcium ions within the apatite crystal lattice. The mineral from treated animals presented increased lattice parameters, which might be associated to their bone strontium contents. In conclusion, the incorporation of strontium occurred in different levels into distinct bones, regions within the same bone and teeth of rats treated with strontium ranelate.
Assuntos
Conservadores da Densidade Óssea/farmacocinética , Osso e Ossos/metabolismo , Compostos Organometálicos/farmacocinética , Estrôncio/metabolismo , Tiofenos/farmacocinética , Dente/metabolismo , Animais , Densidade Óssea , Ratos , Ratos Wistar , Espectrometria por Raios X , Distribuição Tecidual , Difração de Raios XRESUMO
RATIONALE: Isotopic analysis of biogenic tissues such as teeth of elasmobranchs has been well recognized as an important method to interpret present and past environmental conditions. However, few studies on shark teeth have focused their attention on making trophic inferences or reconstruction of diet. METHODS: We analyzed the carbon (δ(13)C) and nitrogen (δ(15)N) isotope composition of the tooth crown and root from blue sharks Prionace glauca caught in southern Baja California using a continuous-flow system by means of an elemental analyzer combined with a Delta Plus XL mass spectrometer, to describe their feeding ecology, considering sex and maturity stage. RESULTS: Significant differences in δ(13)C values for tooth root were found between immature and mature males, with depleted values of (13)C in immature individuals. No statistical differences were found between maturity stages in females for both the C and N isotopes in any part of the tooth, which suggests that females were consuming the same prey in the same area. In addition, we observed significant differences in δ(15)N values between the tooth crown and root. CONCLUSIONS: Isotopic analysis in the tooth crown (dentin) and root may represent a new tool to describe the feeding ecology of different species of elasmobranchs, showing dietary change over a short timescale.
Assuntos
Isótopos de Carbono/análise , Cadeia Alimentar , Isótopos de Nitrogênio/análise , Tubarões/metabolismo , Dente/química , Animais , Isótopos de Carbono/metabolismo , Feminino , Masculino , Biologia Marinha , México , Isótopos de Nitrogênio/metabolismo , Tubarões/crescimento & desenvolvimento , Dente/crescimento & desenvolvimento , Dente/metabolismoRESUMO
UNLABELLED: The embryological, structural and functional unit of the dentine-pulp complex shares the odontoblast, located in the border of the dentine pulp, with basal nuclei and organelles. The odontoblast process emerges from its apical pole. It is formed by microtubules, microfilaments and vesicles covered by membranes penetrating the dentinal tubules, isolated from the inter-tubular matrix, along the extent of the dentine. The objective of this study was to evaluate the efficacy of three staining techniques: hematoxylin-eosin, periodic acid-Schiff and Schmorl, by staining the process, from beginning to end, and compare the results with the erosion technique. Thirty human teeth were employed in the trial; after their extraction the pulp was fixated, the pieces demineralized in nitric acid at 8%, the collagen filaments eliminated with Type II Collagenase, the tissue was stained, and the measurements were made. The portions with no pulp were prepared with the erosion technique. RESULTS: Comparing the best results obtained by staining with the values obtained with the erosion technique, the former showed lower values. CONCLUSION: Staining techniques show lower density of the staining processes compared with the dentinal tubules in the erosion technique.
Assuntos
Odontoblastos/citologia , Odontoblastos/metabolismo , Coloração e Rotulagem , Dente/citologia , Dente/metabolismo , Adolescente , Criança , Corantes , Polpa Dentária/citologia , Polpa Dentária/metabolismo , Feminino , Humanos , MasculinoRESUMO
The embryological, structural and functional unit of the dentine-pulp complex shares the odontoblast, located in the border of the dentine pulp, with basal nuclei and organelles. The odontoblast process emerges from its apical pole. It is formed by microtubules, microfilaments and vesicles covered by membranes penetrating the dentinal tubules, isolated from the inter-tubular matrix, along the extent of the dentine. The objective of this study was to evaluate the efficacy of three staining techniques: hematoxylin-eosin, periodic acid-Schiff and Schmorl, by staining the process, from beginning to end, and compare the results with the erosion technique. Thirty human teeth were employed in the trial; after their extraction the pulp was fixated, the pieces demineralized in nitric acid at 8%, the collagen filaments eliminated with Type II Collage-nase, the tissue was stained, and the measurements were made. The portions with no pulp were prepared with the erosion technique. Results: Comparing the best results obtained by staining with the values obtained with the erosion technique, the former showed lower values. Conclusion: Staining techniques show lower density of the staining processes compared with the dentinal tubules in the erosion technique.
Assuntos
Adolescente , Criança , Feminino , Humanos , Masculino , Odontoblastos/citologia , Odontoblastos/metabolismo , Coloração e Rotulagem , Dente/citologia , Dente/metabolismo , Corantes , Polpa Dentária/citologia , Polpa Dentária/metabolismoRESUMO
The embryological, structural and functional unit of the dentine-pulp complex shares the odontoblast, located in the border of the dentine pulp, with basal nuclei and organelles. The odontoblast process emerges from its apical pole. It is formed by microtubules, microfilaments and vesicles covered by membranes penetrating the dentinal tubules, isolated from the inter-tubular matrix, along the extent of the dentine. The objective of this study was to evaluate the efficacy of three staining techniques: hematoxylin-eosin, periodic acid-Schiff and Schmorl, by staining the process, from beginning to end, and compare the results with the erosion technique. Thirty human teeth were employed in the trial; after their extraction the pulp was fixated, the pieces demineralized in nitric acid at 8%, the collagen filaments eliminated with Type II Collagenase, the tissue was stained, and the measurements were made. The portions with no pulp were prepared with the erosion technique. Results: Comparing the best results obtained by staining with the values obtained with the erosion technique, the former showed lower values. Conclusion: Staining techniques show lower density of the staining processes compared with the dentinal tubules in the erosion technique
Assuntos
Humanos , Masculino , Feminino , Criança , Odontoblastos/citologia , Odontoblastos/metabolismo , Coloração e Rotulagem , Dente/citologia , Dente/metabolismo , Corantes , Polpa Dentária/citologia , Polpa Dentária/metabolismoRESUMO
The embryological, structural and functional unit of the dentine-pulp complex shares the odontoblast, located in the border of the dentine pulp, with basal nuclei and organelles. The odontoblast process emerges from its apical pole. It is formed by microtubules, microfilaments and vesicles covered by membranes penetrating the dentinal tubules, isolated from the inter-tubular matrix, along the extent of the dentine. The objective of this study was to evaluate the efficacy of three staining techniques: hematoxylin-eosin, periodic acid-Schiff and Schmorl, by staining the process, from beginning to end, and compare the results with the erosion technique. Thirty human teeth were employed in the trial; after their extraction the pulp was fixated, the pieces demineralized in nitric acid at 8%, the collagen filaments eliminated with Type II Collagenase, the tissue was stained, and the measurements were made. The portions with no pulp were prepared with the erosion technique. Results: Comparing the best results obtained by staining with the values obtained with the erosion technique, the former showed lower values. Conclusion: Staining techniques show lower density of the staining processes compared with the dentinal tubules in the erosion technique