Pinos de fibra anatômicos: técnica clínica e benefícios mecânicos — relato de caso

Introdução: o emprego de pinos estéticos compostos por fibra de vidro tem sido cada vez mais estudado e os benefícios biomecânicos, além da possibilidade adesiva,tornam viável seu uso em várias situações clínicas. Estudos mostram que a perfeita adaptação às paredes do canal radicular é importante para melhorar as propriedades do conjunto dente-pino. Objetivo: apresentar a sequência técnica de um reembasamento de pino de fibra de vidro em canal amplo de um incisivo central fraturado coronalmente. Relato do caso: paciente do sexo masculino,12 anos de idade, apresentou-se com fratura oblíqua no dente 11 após acidente, atingindo a câmara pulpar.Após tratamento endodôntico, a obturação do canal radicular foi removida em preparo mecânico, resultando em necessidade de reembasamento do pino de fibra (Exacto#3, Angelus), que foi realizado com resina composta microhíbrida (Natural Look, DFL). O pino foi cimentado com adesivo convencional de três passos quimicamente polimerizado (Fusion Duralink, Angelus) e cimento resinoso autopolimeriável (Cement Post, Angelus), sendo posteriormente reconstruída a restauração da fratura dentária. Resultados: alcançou-se ótima resolução funcional e estética, com previsão de grande durabilidade clínica

Influence of powder/liquid ratio on the radiodensity and diametral tensile strength of glass ionomer cements

Clinicians tend to make reductions in glass ionomer power/liquid (P/L) ratios since some materials are difficult to mix and flow into small cavities, grooves or pits. In general, changing the P/L ratio decreases the physical and mechanical properties of conventional glass ionomer cements (GICs) and resin modified glass ionomer cements (RMGICs), but alterations seem to depend on their composition. OBJECTIVE: To determine the influence of P/L ratio on the radiodensity and diametral tensile strength (DTS) of glass ionomer cements. MATERIAL AND METHODS: There were 2 factors under study: P/L ratio (manufacturer's recommended P/L ratio and a 50 percent reduced P/L ratio), and materials (Vitro Molar, Vitro Fil, Vitro Cem conventional GICs and Vitro Fil LC, Ortho Glass LC RMGICs. Five 1-mm-thick samples of each material-P/L ratio were produced for radiodensity evaluation. Samples were x-ray exposed onto Digora phosphor plate and radiodensity was obtained using the software Digora for Windows 2.5 Rev 0. For DTS, five (4.0x8.0 mm) cylinder samples of each material were tested (0.5 mm/min). Data were subjected to one- and two-way ANOVA (5x2) followed by Tukey's HSD test, or Kruskal-Wallis and Dunn's method. For paired comparisons, t-test or Mann-Whitney test were used (α=0.05). RESULTS: There was a significant interaction (P=0.001) for the studied factors (materials vs. P/L ratio). Reduced P/L ratio resulted in significantly lower DTS for the RMGICs, but radiodensity was affected for all materials (P<0.05). CONCLUSIONS: Reduced P/L ratio affected properties of the tested glass ionomer cements. RMGICs were more susceptible to lower values of DTS, but radiodensity decreased for all materials following P/L ratio reduction.

Radiodensity evaluation of dental impression materials in comparison to tooth structures

In the most recent decades, several developments have been made on impression materials' composition, but there are very few radiodensity studies in the literature. It is expected that an acceptable degree of radiodensity would enable the detection of small fragments left inside gingival sulcus or root canals. OBJECTIVE: The aim of this study was to determine the radiodensity of different impression materials, and to compare them to human and bovine enamel and dentin. MATERIAL AND METHODS: Twenty-five impression materials, from 5 classes, were studied: addition and condensation silicones, polyether, polysulfides and alginates. Five 1-mm-thick samples of each material and tooth structure were produced. Each sample was evaluated 3 times (N=15), being exposed to x-ray over a phosphor plate of Digora digital system, and radiodensity was obtained by the software Digora for Windows 2.5 Rev 0. An aluminum stepwedge served as a control. Data were subjected to Kruskal-Wallis and Dunn's method (α=0.05). RESULTS: Different materials and respective classes had a different behavior with respect to radiodensity. Polysulfides showed high values of radiodensity, comparable to human enamel (p>0.05), but not to bovine enamel (p<0.05). Human dentin was similar only to a heavy-body addition silicon material, but bovine dentin was similar to several materials. Generally, heavy-body materials showed higher radiodensity than light-body ones (p<0.05). CONCLUSION: Impression materials' radiodensity are influenced by composition, and almost all of them would present a difficult detection against enamel or dentin background in radiographic examinations.

Mechanical and acid root treatment on periodontally affected human teeth: a scanning electronic microscopy

Aim: To evaluate the root topography of human teeth affected by periodontitis, after different root surface treatments. Methods: Forty-two periodontally affected single-rooted human teeth were selected and randomly divided into 7 groups (n=6): Cont- control group, which received no treatment; Sca- root surface scaling and root planning with curettes; ScaPh- Sca followed by 37%phosphoric acid gel etching for 15 s; ScaEdta- Sca followed by 24% EDTA gel pH 7 for 1 min; ScaCi- Sca followed by 30% citric acid pH 1.6 for 5 min; ScaTe- Sca followed by - mixture obtained by 500 mg tetracycline capsule dissolved in saline solution for 3 min; ScaTeg- Sca followed by 0.2 g/mL tetracycline gel pH 1.8 for 1 min. The specimens were analyzed by scanning electronic microscopy to verify the presence of calculus, demineralization level and residues of the product. Results: Calculus deposits were found in all control specimens. ScaEdta, ScaCi and ScaTeg removed completely calculus deposits and resulted in adequate demineralization without smear layer and smear plug on root surface. ScaTe produced great tetracycline residues with several demineralization areas on root dentin surface. Conclusions: ScaEdta, ScaCi and ScaTeg produced clean root surfaces associated with regular dentin demineralization.

Dental wear caused by association between bruxism and gastroesophageal reflux disease: a rehabilitation report

Bruxism is a pathological activity of the stomatognathic system that involves tooth grinding and clenching during parafunctional jaw movements. Clinical signs of bruxism are mostly related to dental wear and muscular and joint discomforts, but a large number of etiological factors can be listed, as local, systemic, psychological and hereditary factors. The association between bruxism, feeding and smoking habits and digestive disorders may lead to serious consequences to dental and related structures, involving dental alterations (wear, fractures and cracks), periodontal signs (gingival recession and tooth mobility) and muscle-joint sensivity, demanding a multidisciplinary treatment plan. This paper presents a case report in which bruxism associated with acid feeding, smoking habit and episodes of gastric reflow caused severe tooth wear and great muscular discomfort with daily headache episodes. From the diagnosis, a multidisciplinary treatment plan was established. The initial treatment approach consisted of medical follow up with counseling on diet and smoking habits and management of the gastric disorders. This was followed by the installation of an interocclusal acrylic device in centric relation of occlusion (CRO) for reestablishment of the occlusal stability, vertical dimension of occlusion, anterior guides and return to normal muscle activity (90-day use approximately). After remission of initial symptoms, oral rehabilitation was implemented in CRO by means of full resin composite restorations and new interocclusal device for protection of restorations. Satisfactory esthetics, improved function and occlusal stability were obtained after oral rehabilitation. The patient has attended annual follow-ups for the past 2 years. The multidisciplinary treatment seems to be the key for a successful rehabilitation of severe cases of dental wear involving the association of different health disorders.

Effect of blood contamination during adhesive restorative procedures on dentin-resin cement shear bond strength

The aim of this study was to evaluate the effect of dentin blood contamination during different steps of the restorative procedure on resin cement shear bond strength to dentin. Crows of 120 bovine incisors were prepared to obtain flat superficial dentin surfaces. Dentin was etched with phosphoricacid and contaminated with fresh blood for 10 seconds, before or after adhesive system application. Different treatments were tested in contaminated dentin, resulting on eight groups (N=15). Composite resin restorations (TPH Spectrum, Dentsply) were adhesively fixed (Excite, Ivoclar-Vivadent) withresin cement (Variolink 2, Ivoclar-Vivadent) and shear bond strength test (0.5 mm/min) was performed. Morphologic observations were carried out with scanning electron microscopy (SEM). Data (MPa) were submitted to one-way ANOVA following Tukey's test (p<0.05), showing that blood contamination during adhesive procedure negatively affects bond strength, and decontamination methods do not recover original bond strength. The negative effects of bloodcontamination on shear bond strength to dentin and resin cement were significant in all contaminated groups; none of the tested dentin treatment procedures resulted in higher bond strength irrespective of the moment on which blood contamination took place.

Acupuntura como tratamento complementar nas disfunções temporomandibulares; revisão da literatura / Acupuncture as a complementary treatment option to temporomandibular dysfunction: review of the literature

A dor caracteriza-se como um estímulo orgânico de resposta do organismo aalterações que prejudiquem seu pleno funcionamento. Entretanto, dependendo da intensidade e daduração, pode dificultar o estabelecimento de tratamentos que visem eliminar seu fator etiológico.Por isso, seu controle passa a ser encarado como fundamental no plano de tratamento genérico. Asdores crônicas são mais difíceis de serem controladas e freqüentemente são encontradas nas regiõesde cabeça e pescoço. Além dos métodos convencionais de controle da dor, a acupuntura surge naodontologia como método alternativo eficiente e com bons resultados em diversas alterações doaparelho estomatognático, como nas disfunções temporomandibulares. Este artigo tem por objetivorevisar a literatura, avaliando os resultados obtidos nas pesquisas que relacionam a acupuntura como tratamento de dores orofaciais crônicas, especificamente as DTMs, e analisando sua eficiência elimitações em relação às terapias convencionais. A revisão da literatura foi baseada em pesquisana base de dados PubMed, relativa ao período de 1973 a 2004, utilizando as palavras-chaveôacupuncture and temporomandibular dysfunctionõ e selecionando, entre os artigos encontrados,aqueles que correlacionavam a aplicação da acupuntura na Odontologia, especialmente nasdisfunções temporomandibulares. Também foram empregados livros contendo conceitos básicosde dor, fisiologia humana e acupuntura, além de artigos abrangendo princípios de oclusão. Diantedo tema abordado neste artigo é possível concluir que a acupuntura tem se mostrado tão eficienteno controle de dores faciais quanto as terapias convencionais, principalmente em se tratando dedores de origem muscular.

Pain is believed to be an organic stimuli answer from the body to alterations thatmay prejudice its normal function. However, depending on its intensity and period of action, itcan damage the elimination of the etiological factors by the establishment of treatment therapies.On this way, the control of this pain seems to be faced as fundamental on a generic treatmentplan. Chronic pain is the most difficult one to deal with and it is frequently found on head andneck regions. Besides conventional treatment modalities to control pain, acupuncture startedto be used in dentistry as an efficient alternative method with good results when dealing with several types of stomatognathic system alterations, as in temporomandibular dysfunction. Theaim of this study was to review the literature in order to evaluate the results of several researchersthat used acupuncture on the treatment of chronic facial pain, and to compare its efficiency andlimitations with conventional therapies. A PubMed database search was conducted using thekeywords ôacupuncture and temporomandibular dysfunctionõ limited to the period between 1973and 2004. Articles that described the use of acupuncture in dentistry, especially to the treatmentof Temporomandibular Dysfunction, were selected. Textbooks concerning the subjects: pain,human physiology and acupuncture were also included, in addition to articles related to occlusion.According to the principles discussed on this article it is possible to conclude that acupuncture isas efficient as conventional therapies on the control of orofacial pain, principally when the painis of muscle origin.