AbstractWe evaluated the influence of the etching time and temperature of an acid solution (HCl/H2SO4) on the chemical and topographical superficial characteristics of cpTi grade IV. Samples were analyzed by electron microscopy, interferometry, and grazing incidence XRD. The surfaces kept the irregularity aspect when submitted to the same etching temperature. On the other hand, the irregularities increased in size and depth with increasing etching time. The etching treatments that produced higher values for roughness parameters showed a combination of high temperature for a longer etching time. Some treatments produced very large irregularities, with a brittle surface in some regions. According to statistical correlation, the temperature made the strongest contribution in the variance of the mean values of the surface roughness parameters when compared to the etching time. Titanium and oxygen were the only elements on the surface in all groups. All test group samples showed the presence of titanium hydride.

Modifications in texture and surface chemistry are commonly used to increase the biologic response to implants. We evaluated the influence of five different acid etching treatments on the chemical and topographical superficial characteristics of cpTi grade IV discs (test groups). One group of samples were only polished (control group). The samples were analyzed by electron microscopy (SEM, EDS), atomic force microscopy, and grazing incidence XRD. The acid etching treatments which produced higher values for the amplitude roughness parameters showed a combination of strong acids (HF and HCl/H2SO4) at high concentrations, with a relatively high temperature (≥ 60 °C) for a considerable time (≥ 60 min). Titanium and oxygen were the only elements detected by EDS on the surface in all groups, whereas titanium hydride was detected when the samples were analyzed by GIXRD. Only the group subjected to thermal treatment showed presence of rutile phase on the surface.

Some implant manufactures use Al2O3 instead TiO2 powder to sandblast the machined dental implant, because Al2O3 powder is commercially more easily available and is cheaper than TiO2 powder. However, Al2O3 powder usually leaves aluminum oxide contamination on the surface, which is potentially toxic. In this work, we subjected Ti discs previously sandblasted with Al2O3 powder to 5 different acid etchings in order to verify which treatment is able to remove incorporated particles of Al2O3 from the surface. One group of samples were only sandblasted and served as control. The samples were analyzed by electron microscopy (SEM, EDS), scanning probe microscopy, and grazing incidence XRD. The control group showed presence of Al2O3 on the surface. Three acid etchings were efficient in removing the alumina from the tested samples. Almost all the tested samples showed higher roughness parameters values than the control samples. Titanium hydride was found in almost all test groups. Moreover, the results suggest that there is no incorporation of the whole Al2O3 particle into the titanium surface after the collision, conversely a particle fragmentation occurs and what remains on the titanium surface are Al2O3 residues.

We present a detailed investigation of the surface characteristics of five commercial titanium implants with different surface finishing (double acid etching, anodization and incorporation of Ca/P, acid etching and deposition of Ca/P, hydroxyapatite-blasting, acid etching and Ca/P-blasting) produced by five different manufacturers. A set of experimental techniques were employed to study the surface chemical composition and morphology: XPS, XRD, SEM, EDS, and AFM. According to the implat manufacturers, the addition of Ca and P at the implant surface is a main feature of these implants (except the double acid etched implant, which was included for comparative purpose). However, the results showed a great discrepancy on the final amount of these elements on the implant surface, which suggests a different effectiveness of the employed surface finishing methods to fix those elements on the implant surface. Our results show that only the method used by the manufacturer of hydroxyapatite-blasting surface finished implants was efficient to produce a hydroxyapatite coating. This group also showed the highest roughness parameters.

The lack of eruption of a primary tooth can be considered rare. In primary impaction, the primary tooth not only has never appeared in the oral cavity, but also is always covered by a more or less thick layer of bone. Secondary impaction, which is relatively more common, denotes teeth that at one time erupted into the mouth, but subsequently clinically appear to have receded from this position. The purpose of this paper is to present a case of primary and secondary impaction of four primary molar teeth in a single patient.

La falta de erupción de un diente temporal puede ser considerada una situación rara. En la retención primaria, no sólo el diente temporal nunca ha aparecido en la cavidad bucal, sino que también está cubierto por una capa más o menos gruesa del hueso. La retención secundaria, que es relativamente más común, se refiere a los dientes que inició su erupción en la boca, pero clínicamente quedan atrapados en esta posición. El propósito de este trabajo es presentar un caso de retención primaria y secundaria de cuatro molares primarios en un paciente.

Um estudo retrospectivo foi realizado para avaliar fraturas faciais em pacientes atendidos no ano de 2000 em um hospital público de Belo Horizonte. As informações coletadas incluíam idade, sexo, etiologia, distribuição do trauma de acordo com o dia da semana e o mês, o local anatômico da fratura e o tratamento. As análises envolveram estatísticas descritivas, teste qui-quadrado, teste Bonferroni e análise de variância. Foram encontradas 1.326 fraturas de face em 911 pacientes. A maioria das fraturas ocorreu em adultos na faixa etária de 21 a 30 anos. Os homens foram mais acometidos do que as mulheres, numa proporção homem:mulher de 4,69:1. Os traumas causadores de fraturas faciais ocorreram predominantemente nos fins de semana. Os acidentes de moto e bicicleta foram a maior causa de trauma, seguidos por violência interpessoal, acidentes automobilísticos e quedas. Quando analisada a relação entre o gênero e a etiologia das fraturas de face, observou-se uma associação estatisticamente significativa entre essas variáveis (p < 0,001). Houve também uma associação entre a idade dos pacientes e a localização das fraturas (p = 0,0014). O osso facial mais fraturado foi a mandíbula, seguida por complexo zigomático e nariz. O tratamento conservador foi realizado na maioria dos casos. Houve diferenças estatisticamente significativas entre o tipo de tratamento instituído e a localização da fratura (p < 0,001).

A retrospective study was performed to assess facial fractures in patients treated at a public hospital in Belo Horizonte, in 2000. The data collected included age, gender, etiology, distribution of maxillofacial trauma considering day of the week and month, anatomic site of the fracture, and treatment. The analyses involved descriptive statistics and chi-squared test, Bonferroni test and analysis of variance. A total of 1,326 facial fractures were found in 911 patients. Most fractures occurred in adults with age ranging from 21 to 30 years. Men were more affected than women, with a male-female ratio of 4.69:1. Accidents causing facial fractures occurred predominantly on weekends. Bicycle and motorcycle accidents were the major cause of trauma, followed by interpersonal violence, automobile accidents, and falls. When the relation between the gender and the etiology of facial fractures was analyzed, a significant relation was noted between these variables (p < 0.001). There was also a relation between the patients' age and the site of the fractures (p = 0.0014). The mandible was found to be the most commonly fractured bone in the facial skeleton, followed by the zygomatic complex and the nose. A non-surgical approach was chosen in most cases. There were significant differences between the kind of treatment applied and the site of the fracture (p < 0.001).