RESUMO
OBJECTIVES: The purpose of this study was to analyze the physico-chemical changes present on the dentinal surface after using CO2 laser irradiation, and to determine whether or not it is possible to seal the dentinal tubules. METHODS: Thirty human-extracted first premolars were obtained for this study. A Class V cavity was prepared on the buccal surface of all the specimens with a carbide pear-shaped bur, using a conventional high speed handpiece. Fifteen premolars (experimental group) were irradiated with a CO2 laser (with a wavelength of 10.6 microm, 2 W, 10 J, 0.2 s, 25 pulses). The remaining 15 premolars were used as the control group. RESULTS: Scanning electron microscopy showed that the effect of laser energy on dentin varied from charring, cratering, poring, fissuring, fracturing and cracking up to melting; also, the dentinal tubules were not sealed, in contrast with the control group in which the dentinal surfaces were more homogeneous. Particle-induced X-ray emission results showed that the irradiated dentinal surface presented a decrease in calcium content and an increase in phosphorous content, possibly due to a vaporization process which occurred during the irradiation. CONCLUSION: The physicochemical changes observed on the irradiated dentinal surface suggest that changes in the hydroxyapatite crystal structure take place, and that these structural changes may be responsible for the observed effects.
Assuntos
Dentina/efeitos da radiação , Lasers , Dente Pré-Molar , Cálcio/análise , Cálcio/efeitos da radiação , Dióxido de Carbono , Fenômenos Químicos , Físico-Química , Cristalização , Preparo da Cavidade Dentária/classificação , Preparo da Cavidade Dentária/instrumentação , Equipamentos Odontológicos de Alta Rotação , Dentina/ultraestrutura , Durapatita/efeitos da radiação , Microanálise por Sonda Eletrônica , Humanos , Microscopia Eletrônica de Varredura , Fósforo/análise , Fósforo/efeitos da radiaçãoRESUMO
The epidemiologic data on oral lesions in native Indians remain unknown in many countries around the world. This paper reports the prevalence and distribution of oral congenital anomalies and pathologic lesions found in a survey of 107 schoolchildren (ages 12 to 17), from two isolated communities in the ethnographic Mazahua area in the State of Mexico. The main entities identified were: pigmented lesions (47.6%), lingual anomalies (17.4%) and developmental tooth alterations (6.9%). The remaining 24.4% of the lesions were gingival inflammatory hyperplasia, partial ankilosis of the tongue, lichen planus, focal epithelial hyperplasia and the double lip. The most frequent localization was lips and tongue. These findings suggest the high prevalence of oral anomalies in this Indian population. Therefore, we suggest that health programs should emphasize the prevention, diagnosis and treatment of these pathologies in Indians groups.
Assuntos
Indígenas Norte-Americanos/estatística & dados numéricos , Doenças da Boca/epidemiologia , Adolescente , Criança , Feminino , Hiperplasia Gengival/epidemiologia , Humanos , Líquen Plano Bucal/epidemiologia , Masculino , México/epidemiologia , Anormalidades da Boca/epidemiologia , Transtornos da Pigmentação/epidemiologia , Prevalência , Língua/anormalidades , Anormalidades Dentárias/epidemiologiaRESUMO
The epidemiologic data on oral lesions in native Indians remain unknown in many countries around the world. This paper reports the prevalence and distribution of oral congenital anomalies and pathologic lesions found in a survey of 107 schoolchildren (ages 12 to 17), from two isolated communities in the ethnographic Mazahua area in the State of Mexico. The main entities identified were: pigmented lesions (47.6
), lingual anomalies (17.4
) and developmental tooth alterations (6.9
). The remaining 24.4
of the lesions were gingival inflammatory hyperplasia, partial ankilosis of the tongue, lichen planus, focal epithelial hyperplasia and the double lip. The most frequent localization was lips and tongue. These findings suggest the high prevalence of oral anomalies in this Indian population. Therefore, we suggest that health programs should emphasize the prevention, diagnosis and treatment of these pathologies in Indians groups.
RESUMO
The epidemiologic data on oral lesions in native Indians remain unknown in many countries around the world. This paper reports the prevalence and distribution of oral congenital anomalies and pathologic lesions found in a survey of 107 schoolchildren (ages 12 to 17), from two isolated communities in the ethnographic Mazahua area in the State of Mexico. The main entities identified were: pigmented lesions (47.6
) and developmental tooth alterations (6.9
of the lesions were gingival inflammatory hyperplasia, partial ankilosis of the tongue, lichen planus, focal epithelial hyperplasia and the double lip. The most frequent localization was lips and tongue. These findings suggest the high prevalence of oral anomalies in this Indian population. Therefore, we suggest that health programs should emphasize the prevention, diagnosis and treatment of these pathologies in Indians groups.
RESUMO
OBJECTIVE: To determine the concentration of lead (Pb), cadmium (Cd), and chromium (Cr) and establish the possible association of these heavy metals with some sociodemographic factors. MATERIAL AND METHODS: A representative sample of one hundred dental students from the National Autonomous University of Mexico living in Mexico City participated in this study. Unstimulated human whole saliva samples were analyzed by Atomic Absorption Spectroscopy. RESULTS: Concentrations of Pb, Cd, and Cr were higher than those reported elsewhere: Pb (X = 3.10 micrograms/dL-1; Maximum: 16.8 micrograms/dL-1 and Minimum: 0.04 microgram/dL-1), Cd (X = 0.25 microgram/dL-1; Maximum: 2.04 micrograms/dL-1 and Minimum: 0.004 microgram/dL-1) and Cr (X = 1.43 micrograms/dL-1; Maximum: 4.82 micrograms/dL-1 and Minimum: 0.05 microgram/dL-1). No association was found between the variables studied (age, sex, geographic area and canned food consumption) with Pb and Cr. However, an inverse association was found between Cd and age (Chi 2 = 5.9012, p < or = 0.05); (gamma = -0.5224, p < or = 0.05). CONCLUSIONS: Salivary monitoring can be used for detection of environmental pollutants (atmospheric or occupational), in addition for detection of drugs, and local and systemic diseases. Heavy metal pollution continues to be a public health problem, and therefore the government should form a program for eliminating pollutants from the environment. Likewise, other studies should be carried out to verify the association between variables such as sex, age, use of glazed ceramics, nutrition, and home address with the concentrations of heavy metals in saliva.
Assuntos
Cádmio/análise , Cromo/análise , Chumbo/análise , Saliva/química , Adulto , Fatores Etários , Interpretação Estatística de Dados , Poluentes Ambientais/análise , Feminino , Humanos , Masculino , México , Fatores Sexuais , Espectrofotometria AtômicaRESUMO
Mexico city has a very high pollution index. Based on the view 'that salivary monitoring can be extended to environmental pollutants', we performed this study in order to determine not only the concentrations of lead and cadmium in human saliva, but also to establish their possible association with some socio-demographic factors. One hundred dental students from the National Autonomous University of Mexico living in Mexico city participated in the study. Stimulated human whole saliva samples were analyzed by atomic absorption spectroscopy. The results show that Pb (x = 3.10 microg/dl(-1); maximum x = 16.8 microg/dl(-1) and minimum x = 0.04 microg/dl[-1]) and Cd (x = 0.25 microg/dl(-1); maximum x = 2.04 microg/dl(-1) and minimum x = 0.004 microg/dl[-1]) concentrations were higher than those reported elsewhere, and that there was no association between several variables studied (age, gender, geographic area and consumption of canned food) and salivary Pb. However, an inverse association was found between Cd and age (chi2 = 5.9012; P < or = 0.05; gamma = -0.5224, P < or = 0.05). From this study it can be concluded that saliva has potential as a technique for monitoring ambient pollutants recent exposure, since circulating levels of certain polluting chemicals can be transported into salivary glands and secretions.