Topography and presence of a smear layer in deciduous molars prepared with high-speed cutting and ultrasonic abrasion: an in-vitro study.

OBJECTIVE: The aim of this in-vitro study was to compare the effect of high-speed cutting (HS) with ultrasonic abrasion (US) concerning the internal topography and the presence of a smear layer in a cavity preparation performed in healthy deciduous molars. MATERIAL AND METHODS: Seven first deciduous molars were used. Two occlusal cavity preparation were done, one in the medial fossula and another in the distal fossula, which were chosen randomly. One preparation was carried out with a diamond point adapted to the HS system (GI), while a chemical vapor deposition (CVD) point adapted to a US device (GII) was used for the other preparation. Subsequently, all samples (n = 14) were cleaved to observe the inside and then prepared for evaluation using scanning electron photomicroscopy. The internal topography of the prepared cavities was descriptively analyzed. In order to assess the presence of a smear layer, scores were tabulated using the 2000 GMC program and analyzed using the Mann-Whitney test. RESULTS: Concerning the internal topography, the presence of striae was verified in both groups. In the GI group they were finer, found in a greater number, and with narrower spaces between them. In the GII group, the striae were undulating, similar to the effect of wheels on sand, and with wider spaces between them. As regards the presence of a smear layer, there was no statistically significant difference between the groups (P > 0.05). CONCLUSIONS: In view of the methodology employed, it may be concluded that cavity preparation with a CVD point in a US abrasion system led to the formation of fewer striae and both devices promoted the marked presence of a smear layer, obstructing dentinal tubuli.

Effectiveness of high speed instrument and air abrasion on different dental substrates.

The aim of this study was to compare the effectiveness of high speed (HS) and air abrasion (AA) instruments on groups of teeth (deciduous, permanent, bovine), in terms of preparation time, topography and presence of smear layer. Each group consisted of 5 teeth that had their buccal/lingual surfaces prepared by using either HS or AA. All procedures were standardized and timed. The teeth were then sectioned and prepared for evaluation of both the topography and the presence of smear layer by scanning electron microscopy. As regards preparation time, HS yielded preparations 1.5 times quicker than AA did on the three types of dental substrates (Wilcoxon test, p < 0.05). In both techniques (Kruskal-Wallis Test, p < 0.05) the preparation time was influenced by the dental substrate, particularly in deciduous teeth (Mann-Whitney test with Bonferoni's correction, p < 0.017), which required a longer preparation time. In the descriptive analysis of the topography, no difference was found between the substrates. Nonetheless, the different instruments used determined distinctive topographies. Both techniques produced a smear layer (chi2 McNemar, p > 0.05) in all substrates, but with different formations. In conclusion, the HS instrument was found to be more rapid than the AA. No difference was found between the three dental substrates as regards both the topography and the presence of smear layer. The differences found in the present study were only in relation to the effects of each instrument used.

Influence of kinetic cavity preparation devices on dental topography: an in vitro study.

AIM: The objectives of this study were to assess the influence of four different kinetic cavity preparation devices on cavity preparation taking into account tip angulation, internal tip diameter, and distance to the dental substrate. The dental topography itself was also evaluated after the use of these devices. METHODS AND MATERIALS: Quantitative parameters using pertinent statistical tests as well as qualitative parameters were used to assess the topography in terms of the dispersion halo effect (DHE), size, and depth of the preparation. RESULTS: The DHE did not present differences among the groups. In relation to the preparation size, the internal diameter influenced 120 masculine point angles, whereas distance influenced the 90 masculine ones. Considering the preparation depth, the 90 degrees point angle yielded the deepest. In the qualitative analysis, both angles provided cavity preparations with rounded cavosurface angles. The 120 masculine point angles yielded inclined, shallow V-shaped preparations, whereas the 90 masculine angles presented U-shaped preparations reaching the dentin. The enamel had an irregular aspect and exposed prisms; dentin had a loose smear layer with aluminum oxide residues. CONCLUSION: The kind of device may influence the kinetic cavity design. CLINICAL SIGNIFICANCE: It is the clinician that knows how to select the appropriate devices to adopt in order to achieve the desired cut, depth, and shape of cavity preparations.

Effectiveness of high speed instrument and air abrasion on different dental substrates

The aim of this study was to compare the effectiveness of high speed (HS) and air abrasion (AA) instruments on groups of teeth (deciduous, permanent, bovine), in terms of preparation time, topography and presence of smear layer. Each group consisted of 5 teeth that had their buccal/lingual surfaces prepared by using either HS or AA. All procedures were standardized and timed. The teeth were then sectioned and prepared for evaluation of both the topography and the presence of smear layer by scanning electron microscopy. As regards preparation time, HS yielded preparations 1.5 times quicker than AA did on the three types of dental substrates (Wilcoxon test, p < 0.05). In both techniques (Kruskal-Wallis Test, p < 0.05) the preparation time was influenced by the dental substrate, particularly in deciduous teeth (Mann-Whitney test with Bonferoni's correction, p < 0.017), which required a longer preparation time. In the descriptive analysis of the topography, no difference was found between the substrates. Nonetheless, the different instruments used determined distinctive topographies. Both techniques produced a smear layer (÷2 McNemar, p > 0.05) in all substrates, but with different formations. In conclusion, the HS instrument was found to be more rapid than the AA. No difference was found between the three dental substrates as regards both the topography and the presence of smear layer. The differences found in the present study were only in relation to the effects of each instrument used.

Severe tongue injury in an adolescent with epilepsy: a case report.

Epilepsy and other neurological disorders can have profound social, physical and psychological consequences, especially when they begin in childhood. Moreover, seizure episodes may cause fractures, burns, head injuries and oral injuries. This report presents a case history of an adolescent with a severe tongue injury related to epileptic seizures and outlines the proposed treatment, which included use of a maxillary silicone bite guard that allowed healing of the tongue injury within a few months.

Abrasão ultra-sônica: uma alternativa para a confecção de preparos cavitários / Ultrasonic abrasion: an alternative in the performance of cavitary preparations

Introdução: A odontologia restauradora visa reparar os danoscausados pela cárie. Ao longo dos anos, pesquisadores vêmdesenvolvendo métodos eficazes e menos invasivos objetivandoa preservação do órgão dental no combate desta doença. Logo, oaprofundamento de conhecimentos científicos, sistemas auxiliaresde diagnóstico, materiais dentários e novos instrumentos de trabalhotêm mudado a abordagem e os tratamentos desta. Além da remoçãoconservadora do tecido cariado, também o conforto do pacientepassou a ser preocupação constante da odontologia moderna.Objetivo: Considerando que a abrasão ultrassônica temdespertado grande interesse dos profissionais da área deodontologia, este artigo teve por objetivo discutir uma técnicaalternativa para confecção de preparos cavitários, através de umarevisão da literatura abordando suas indicações, contra-indicações,vantagens e limitações comparadas ao método convencional dealta-rotação.Conclusão: Não havendo muitos estudos de pesquisa sobre oassunto, os que existem vêm demonstrando diversas qualidadesdo sistema de abrasão ultrassônica, no entanto ainda há algunspontos duvidosos. Por isso, é importante enfatizar que estudoslaboratoriais e clínicos em dentes decíduos/permanentes aindadevem ser desenvolvidos, para elucidar fatos ainda questionáveiscomo tempo de preparo cavitário, topografia, presença de smearlayer, e microinfiltração, a fim de oferecer segurança para o usoextensivo desta nova tecnologia tanto para o profissional, quantopara o paciente. Neste contexto, o clínico deverá sempre ficaratento para inovações das técnicas minimamente invasivas.

Self-inflicted oral trauma in a baby with Moebius syndrome.

Moebius syndrome (MS) is a rare disorder mainly characterized by bi- or unilateral palsy of the facial and abducens nerves. Among the various orofacial characteristics related to this syndrome, the following are pointed out, difficulty with sucking, tongue malformation, mandibular hypoplasia, saliva drooling, arched palate and micrognathia. In spite of the diversity of oral features described for these patients, self-inflicted oral trauma has not yet been reported. Therefore, the purposes of the present report were to describe an unusual case of a baby with Moebius syndrome who had a parafunctional habit that resulted in a persistent traumatic lesion of the lower lip, and discuss the treatment performed.

Analysis of primary and permanent molars prepared with high speed and ultrasonic abrasion systems.

The aim of this study was to compare high speed and ultrasonic systems with regard to both topography and smear layer formation in the cavity preparations of sound primary and permanent molars. Class I occlusal cavities measuring 2.00 x 2.00 x 2.00 mm were performed in 14 molars, equally divided into two groups (GI = 7 primary teeth and GII = 7 permanent teeth). High speed rotary instruments produced regular layers of enamel and dentin, despite the marked presence of grooves and microfractures on enamel surfaces. On the other hand, ultrasonic abrasion yielded more irregular surfaces in enamel and dentin, with a granular and wavy aspect, but without microfractures in enamel. Both types of dental substrates were found to have an intense smear layer formation, partially or even completely obliterating the dentinal tubules (p>0.05), irrespective of the instrument used. No difference was observed in either primary or permanent teeth as regards the amount of smear layer produced by high speed or ultrasonic abrasion instruments (p>0.05). It was concluded that with regard to the topography of cavity preparations, there were differences between the instruments used, irrespective of the dental substrate. Both systems allowed dense smear layer formation, which completely or partially obliterated the dentinal tubules of primary and permanent teeth.

Ligneous periodontitis and Ehlers-Danlos syndrome.

BACKGROUND: Generalized membranous gingival enlargement due to an accumulation of fibrin deposits associated with severe alveolar bone loss (ligneous periodontitis) is a rare condition, and plasminogen deficiency seems to play a central role in its pathogenesis. However, this condition has not been described in association with syndromes. This article reports a case of ligneous periodontitis in a boy with the classic type of Ehlers-Danlos syndrome (EDS). METHODS: A 12-year-old white male presented with generalized gingival overgrowth and severe alveolar bone loss. A physical examination revealed clinical signs of EDS (velvety skin with mild hyperextensibility, marked hypermobility of the limb joints, atrophic scars on his knees, and easy bruising), which is associated with a positive family history for joint hypermobility. A biopsy of gingival tissues was submitted for routine histology, hematoxylin and eosin (H&E), and direct immunofluorescence (antifibrinogen). An evaluation of plasminogen activity was also performed. RESULTS: Histopathology revealed chronic periodontitis with fibrinoid material deposition, and direct immunofluorescence proved to be positive for fibrin. Functional plasminogen was reduced. A conclusive diagnosis of ligneous periodontitis due to plasminogen deficiency associated with the classic type of EDS was rendered. CONCLUSIONS: Ehlers-Danlos syndrome can be associated with ligneous periodontitis. In the present case, the histologic examination represented an important tool in the differential diagnosis, because it ruled out EDS type VIII as the associated systemic factor to periodontal breakdown.

Sistema de abrasão a ar em odontologia: revisão de literatura / Air abrasion system in dentistry: a literature review

Introdução: A preservação da saúde do dente natural de cada paciente é o objetivo básico da odontologia moderna. Na odontopediatria, esse propósito associado à interceptação precoce de problemas na cavidade bucal de forma segura e confortável é a meta a ser alcançada por todo profissional que lida com criança. Para isso, o aprofundamento de conhecimento científicos, sistemas auxiliares de diagnóstico, materiais dentários e novos instrumentos de trabalho têm mudado a visão do cirurgião dentista na maneira de lidar com a cárie. Objetivo: Desse modo esse artigo teve por objetivo por meio de uma revisão de literatura abordar e discutir os fatos que levaram à reintegração no uso clínico de um sistema conservador de preparo cavitário existente desde 1945: a abrasão a ar. Conclusão: Assim pôde-se observar que é muito importante conhecer os objetivos, limitações e indicações do uso desse sistema, bem como, a necessidade de estabelecimento de parâmetros para o seu uso, principalmente noque se refere ao fato da adesividade e microinfiltração do meterial sobre os substratos dentários (dentes decíduos ou permanentes)

Preparo do paciente pediátrico portador de diabetes e Síndrome de Down para tratamento dentário sob anestesia geral / Managing the diabetic paediatric patient with Down Syndrome for dental treatment under general anaesthesia

O diabetes é uma doença caracterizada pela elevaçäo da glicose no sangue, e pela emissäo freqüente e abudante de urina. Devido a sua natureza imunológica, está associado à diversas outras síndromes, de forma que na avaliaçäo clínica destes pacientes, principalmente naqueles que deveräo ser submedidos à procedimentos cirúrgicos, deve-se incluir sempre investigaçäo para a possibilidade da associaçäo com outras doenças. Dessa forma, o objetivo deste artigo foi relatar o preparo de uma paciente diabética portadora da Síndrome de Down, atendida na Unidade Pediátrica de Pacientes Especiais (UPPE) da Faculdade de Odontologia de uma instituiçäo pública de ensino superior, que foi submetida à tratamento dentário sob anestesia geral