Influence of preheating and post-curing on a novel fiber-reinforced composite post material

Abstract The aim of this study was to investigate the influence of preheating and post-curing methods on diametral tensile strength (DTS), flexural strength (FS), knoop microhardness (KHN), and degree of conversion (DC) of an experimental fiber-reinforced composite (FRC). Specimens (30 wt% of 3-mm-short E-glass fiber, 22.5 wt% of methacrylated-based resin and 47.5 wt% of filler particles) were subjected to: P - photocuring at 1500 mW/cm2 for 40 s (control); P/M - photocuring and microwave post-curing (540W/5 minutes); P/A - photocuring and autoclave post-curing (120°C/15 minutes); PH-P - preheating (60°C) and photocuring; PH-P/M - preheating, photocuring and microwave post-curing; and PH-P/A - preheating, photocuring and autoclave post-curing. Specimens for DTS (Ø 3 x 6 mm) and FS (25 x 2 x 2 mm) were tested at Instron 5965. KHN employed a 50g load for 30s. DC was measured using FTIR spectroscopy. Statistical analysis employed: factorial analysis, normality test, one-way ANOVA and Tukey's HSD test, independent T-test and the Dunnett test. Interaction between factors was not significant (P>0.05). Preheating promoted significantly higher values of FS and KHN (p = 0.0001). Post-curing promoted significantly higher values for KHN (p = 0.0001). For DTS (p = 0.066) and DC (p= 0.724) no statistical difference was found between groups. SEM images showed that preheating promoted better interaction between glass fibers and resin matrix. Preheating increased FS, KHN and DTS, and post-curing increased KHN. DC was not affected by both methods. Preheating and post-curing methods can be used to improve some mechanical properties of FRCs' but degree of conversion remains unaffected.

Influence of the powder/liquid ratio and storage time of conventional glass ionomer cements in diametral tensile strength

Introduction: The Glass Ionomer Cements (GICs) are the most versatile dental material with extensive clinical indication. However, the mechanical strength of conventional GICs (C-GICs) is still unsatisfactory under areas of masticatory forces. Objective: To evaluate the influence of C-GIC proportioning system (powder-liquid and encapsulated) and storage period (1h, 24h and 7 days) on Diametral Tensile Strength (DTS). Material and methods: The two variables were tested in relation to C-GIC (Riva Self Cure, SDI, Australia). The following proportioning systems were tested: powder-liquid by weight (g:g) and powder-liquid by volume (flat scoop: drop) and encapsulated system (pre-dosed capsules). Five C-GIC specimens were prepared, according to ISO specification #9917 for each variable to be studied. The specimens were stored in plastic containers containing distilled water and kept at 37ºC and 100% humidity until the mechanical testing in a universal testing machine (Instron Corp., USA) at a speed 0.5 mm/min. The data were submitted to two-way ANOVA and Tukey test for multiple comparisons (α = 0.05). Results: The proportioning system (P < 0.0001) and storage time (P < 0.0001) were significant predictors of DTS, however with no interaction between these factors. Conclusion: The DTS of C-GICs was influenced by storage time (1 hour < 24 hours < 7 days) and by the proportioning system only for the initial period of its setting reaction.

Comparação entre enxerto autógeno e xenógeno no levantamento do seio maxilar: relato de caso clínico com dois anos de acompanhamento clínico e por tomografia computadorizada de feixe cônico / Comparison between intra-oral autogenous and one xenogeneic bone source for maxillary sinus lifting: a case report with 2-year follow-up clinical and CBCT results

O objetivo deste trabalho foi analisar, por meio de imagens radiológicas, a regeneração óssea nas regiões posteriores de maxila atrófica após procedimento de levantamento de seio maxilar com utilização, em diferentes sítios cirúrgicos, de enxerto ósseo autógeno e enxerto ósseo xenógeno (Bio-Oss). No procedimento cirúrgico, a região anterior foi enxertada com osso autógeno em bloco, proveniente do ramo mandibular direito; o seio esquerdo foi levantado com osso autógeno proveniente do ramo mandibular esquerdo; e o seio direito foi preenchido com osso xenógeno (Bio-Oss). Posteriormente, foram instalados os implantes e a prótese tipo protocolo após osseointegração. Após acompanhamento de dois anos, verificou-se aumento da densidade óssea nos sítios enxertados, bem como estabilização dos implantes em harmonia com a prótese.

The aim of this paper was to analyze through radiological images the bone regeneration at posterior atrophic maxillary regions after sinus lifting in different surgical sites using autogenous and xenogeneic bone grafts (Bio-Oss). On surgery, the anterior region was grafted with block autogenous bone from the right mandibular ramus; the left sinus was lifted with autogenous material from the left mandibular ramus; and the right sinus area received a xenogeneic material. After, dental implants were placed and a fixed total prosthesis was delivered after the osseointegration period. The 2-year follow-up images demonstrated an increase on the density at the grafted sites, as well as implant stability and adequate prosthetic integration.

Técnica de estratificação e texturização superficial de resinas compostas em dentes anteriores: seis meses de acompanhamento / Layering technique and surface texturization of composite resins in anterior teeth: six month follow-up

Este relato de caso apresenta uma alternativa conservadora para reanatomização de dentes conóides e fechamento de diastemas. O método escolhido foi uma técnica restauradora adesiva direta com resinas compostas, estratificada com diferentes camadas e cores, e posterior texturização superficial durante as fases de acabamento e polimento finais. As restaurações resultaram em dentes reanatomizados, reproduzindo naturalidade de forma, textura e cor, mantidas pelos seis meses em que a paciente foi acompanhada. Com planejamento adequado, enceramento diagnóstico e estratificação-texturização com resinas compostas, foi possível restabelecer o sorriso com proporções, forma e naturalidade satisfatórias.

This report presents an alternative, conservative treatment for reshaping conoid teeth and diastema closure. The chosen method was a direct restorative technique with composite resins, stratified with different masses and shades, and subsequent surface texturization during the final stages of finishing and polishing. The final restorations reproduced naturally the form, texture and shade, followed-up for 6 months. After proper planning, diagnostic wax-up and stratification/surface texturization of composite resins reestablished the smile with pleasant proportions, shape and life-like appearance of the smile

Effect of light sources and curing mode techniques on sorption, solubility and biaxial flexural strength of a composite resin

Adequate polymerization plays an important role on the longevity of the composite resin restorations. OBJECTIVES: The aim of this study was to evaluate the effect of light-curing units, curing mode techniques and storage media on sorption, solubility and biaxial flexural strength (BFS) of a composite resin. MATERIAL AND METHODS: Two hundred and forty specimens were made of one composite resin (Esthet-X) in a stainless steel mold (2 mm x 8 mm Ø), and divided into 24 groups (n=10) established according to the 4 study factors: light-curing units: quartz tungsten halogen (QTH) lamp and light-emitting diodes (LED); energy densities: 16 J/cm² and 20 J/cm²; curing modes: conventional (CM) and pulse-delay (PD); and permeants: deionized water and 75% ethanol for 28 days. Sorption and solubility tests were performed according to ISO 4049:2000 specifications. All specimens were then tested for BFS according to ASTM F394-78 specification. Data were analyzed by three-way ANOVA followed by Tukey, Kruskal-Wallis and Mann-Whitney tests (α=0.05). RESULTS: In general, no significant differences were found regarding sorption, solubility or BFS means for the light-curing units and curing modes (p>0.05). Only LED unit using 16 J/cm² and PD using 10 s produced higher sorption and solubility values than QTH. Otherwise, using CM (16 J/cm²), LED produced lower values of BFS than QTH (p<0.05). 75% ethanol permeant produced higher values of sorption and solubility and lower values of BFS than water (p<0.05). CONCLUSION: Ethanol storage media produced more damage on composite resin than water. In general the LED and QTH curing units using 16 and 20 J/cm² by CM and PD curing modes produced no influence on the sorption, solubility or BFS of the tested resin.

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.

Resistência Adesiva do Cimento de Ionômero de Vidro a Restaurações em Resina Composta –Revisão da Literatura / Bond Strength of glass Ionomer Cement to Composite Resin Restorations - a Literature Review

Os cimentos de ionômero de vidro são usados normalmentecomo protetores do complexo dentino-pulpar. O presenteestudo objetivou analisar, através de revisão da literatura,como ocorre a união adesiva destes cimentos a restauraçõesde resina composta. O levantamento bibliográfico foi realizadonas bases de dados: PUBMED, Portal de Periódicos CAPES,SCIELO, BBO, BIREME e LILACS. A seleção das publicaçõesfoi realizada utilizando-se os descritores (português/inglês):cimentos de ionômeros de vidro/glass ionomer cements,resinas compostas/composite resins, resistência de união/bond strength e propriedades mecânicas/mechanicalproperties. O período determinado para seleção dos artigosfoi fixado entre os anos 1995 e 2010 e, após filtragem, 23artigos foram selecionados. Diferentes variáveis estãoenvolvidas no processo de união entre o cimento e a resinacomposta. A composição, o tempo decorrido entre a inserçãodo cimento e a realização da restauração, bem como a técnicautilizada é importantes fatores. Os cimentos modificados porresina apresentaram resultados de comportamento clínicosuperiores aos convencionais. A união entre cimento e resinacomposta deve ser realizada imediatamente após a inserçãodo primeiro na cavidade. O sistema adesivo autocondicionanteaumentou a resistência adesiva entre osmateriais quando aplicado sobre o cimento antes de suapresa inicial. Adesivos com composição semelhante à de umionômero resinoso aumentaram a resistência de união apósa presa do cimento...

Glass ionomer cements are widely used as protectors of thepulp-dentin complex. This study aimed to examine, through aliterature review, how adhesive bonding is establishedbetween those cements and composite resin restorations. Abibliographic research was conducted in the databases:PubMed, CAPES, SCIELO, BBO, LILACS and BIREME. Paperswere selected using the descriptors (Portuguese / English):cimentos de ionômeros de vidro/glass ionomer cements,resinas compostas/composite resins. The period determinedfor their selection was set between 1995 and 2010, andafter filtration, 23 articles were selected. It was observedthat different variables are involved in the process of bondstrength between glass ionomer and composite resin. Thecomposition, the elapsed time between the insertion of thecement and execution of the restoration, as well as therestorative technique are important factors. The resinmodifiedcements presented results clinically superior to thosefound for conventional cements. Bonding between cementand composite resin should be performed immediately afterinsertion of the cement in the prepared cavity. The self-etchingadhesive system increased bond strength values whenapplied over glass ionomer before initial setting. Adhesiveswith a composition similar to that of resin modified ionomerincreased bond strength after cement’s setting...

Inorganic particle analysis of dental impression elastomers

The aim of this study was to determine quantitatively and qualitatively the inorganic particle fraction of commercially available dental elastomers. The inorganic volumetric fraction of two addition silicones (Reprosil Putty/Fluid and Flexitime Easy Putty/Fluid), three condensation silicones (Clonage Putty/Fluid, Optosil Confort/Xantopren VL and Silon APS Putty/Fluid), one polyether (Impregum Soft Light Body) and one polysulfide (Permlastic Light Body) was accessed by weighing a previously determined mass of each material in water before and after burning samples at 600ºC, during 3 h. Unsettled material samples were soaked in acetone and chloroform for removal of tthe organic portion. The remaining filler particles were sputter-coated with gold evaluation of their morphology and size, under scanning electron microscopy (SEM). Flexitime Easy Putty was the material with the highest results for volumetric particle fraction, while Impregum Soft had the lowest values. Silon 2 APS Fluid presented the lowest mean filler size values, while Clonage Putty had the highest values. SEM micrographs of the inorganic particles showed several morphologies - lathe-cut, spherical, spherical-like, sticks, and sticks mixed to lathe-cut powder. The results of this study revealed differences in particle characteristics among the elastometic materials that could lead to different results when testing mechanical properties.

O objetivo desse estudo foi determinar quantitativamente e qualitativamente a fração de partículas inorgânicas de elastômeros dentais disponíveis comercialmente. A fração volumétrica de dois silicones por adição (Reprosil Denso/Fluído e Flexitime Denso/Fluído), três silicones por condensação (Clonage Denso/Fluído, Optosil/Xantopren, e Silon 2 APS Denso/Fluído), um poliéter (Impregum Soft Light) e um polissulfeto (Permlastic Light Body) foi determinada pela pesagem prévia de uma determinada massa de cada material em água antes e após a queima das amostras a 600ºC, por 3 h. Amostras de material não polimerizado foram imersas em acetona e clorofórmio para a remoção da parte orgânica. As partículas de carga remanescentes foram cobertas com uma camada de ouro para avaliação da sua morfologia e tamanho, em microscopia eletrônica de varredura. O material Flexitime Denso foi o material com maior fração volumétrica de partículas de carga, enquanto que o Impregum teve menor fração volumétrica. Silon 2 APS Fluído apresentou partículas de carga de menor tamanho, enquanto que o Clonage Denso apresentou as maiores partículas. A observação em MEV. mostrou partículas de carga com vários tipos de morfologia (esféricas, irregulares, semi-esféricas, retangulares e mistura de retangulares/irregulares). Os resultados desse estudo mostraram diferenças nas partículas de carga dos materiais, as quais podem levar a diferentes resultados em suas propriedades mecânicas.

Cavity preparation machine for the standardization of in vitro preparations

Several in vitro studies employ the confection of cavity preparations that are difficult to standardize by means of manual high speed handpieces. This study presents the development of a cavity preparation machine designed to standardize in vitro cavity preparations. A metal base of 25 mm x 25 mm x 4 mm (length x width x height) was coupled to a small mobile table which was designed to be able to move by means of two precision micrometers (0.01-mm accuracy) in the horizontal directions (right-left, and back-front). A high speed handpiece was coupled to a metallic connecting rod which had an accurate dial indicator enabling control of the vertical movement. The high speed handpiece is also able to move 180° around its longitudinal axis and 360° around its transversal axis. The suggested cavity preparation machine precisely helps in the standardization of cavity preparations for in vitro studies.

Correlation between marginal accuracy and fracture resistance of indirect composite restorations varying cavity preparation design

This study evaluated the correlation between marginal accuracy and fracture resistance of laboratory-processed resin composite (LPRC) restorations with different cavity preparation designs. Eighty human third mandibular molars were selected and divided into 8 groups (n=10): G1 û conservative (-c) inlay; G2 û extensive (-e) inlay; G3 û onlay-c with mesio-buccal cusp coverage (CC); G4 û onlay-e with mesiobuccal CC; G5 û onlay-c with buccal CC; G6 û onlay-e with buccal CC; G7 û onlay-c with total CC; G8 û onlay-e with total CC. Indirect composite restorations (SR Adoro, Ivoclar-Vivadent) were manufactured and positioned over each respective preparation. Marginal accuracy was assessed using a stereomicroscope at 3 points on buccal, lingual, mesial and distal regions (40x magnification). After adhesive cementation (Adper Single Bond 2 and Rely-X ARC, 3M ESPE) a load compressive test (0.5mm/minute) was performed. Data were recorded in mm (marginal accuracy) and Kgf (fracture resistance). In general, Pearson correlation coefficient (a=0.05) did not show significance between factors in study (r=0.073; p=0.520) but it showed significance only on G6 (r=0.702; p=0.024). Irrespective of the preparation design it seems difficult to state the clear correlation between marginal accuracy and fracture resistance of LPRC restored teeth. In this study the effect of one variable on another was negligible.

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.

Influence of root depth and the post type on Knoop hardness of a dual-cured resin cement

Fiber posts are usually luted to the root canal with dual-cured resin cements. However, some of these cements require light-activation in order to reach optimal degree of cure. The aim of this study was to evaluate the effect of the fiber post type on microhardness of a dualcured resin cement used for luting these posts. After endodontic treatment, four fiber post types were luted to the root canal of bovine incisors with RelyX ARC. The samples were sectioned in order to obtain four slices, representing different depths (0.0; 2.5; 5.0; 7.5 and 10.0mm). Knoop microhardness testing was performed in eachslice. The data were submitted to split-plot ANOVA and Tukey post-hoc tests. An additional sample per fiber post type was used to analyze bonding interface by SEM. At the depths of 0 and 2.5 mm, the resin cement presented the highest hardness values. The lowest values were observed at the 10 mm depth, and the resin cement presented intermediary hardness means at the depths of 5 mm and 7.5 mm. By means of scanning electronic microscopy, it was possibleto see the more homogeneous hybrid layer in the cervical region of the root.

Influence of time elapsed between application and adhesive polymerization on the bond strength to dentin

The aim of this study was to evaluate the influence of time elapsed between dentin adhesive application and its polymerization on the bond strength to dentin. Superficial bovine dentin received the following treatments: Single Bond (3M/ESPE Dental Products Division, St.Paul, MN, USA), Excite (Ivoclar/Vivadent, Schaan, Liechtenstein), Prime&Bond 2.1 (Dentsply/Caulk, Milford, DE, USA) and One-Up Bond F (Tokuyama Corp.,Tokyo, Japan) being polymerized immediately after its application, 10 and 20 seconds after application. After, indirect composite restoration was fixed with resinous cement RelyX Arc (3M/ESPE). The restoration/tooth interface was observed on Scanning Electron Microscopy (SEM). Bond strength was accessed through a shear bond test on a testing machine at 0.5 mm/min. Data were compared by ANOVA followed by Tukey test (á=0.05). The failure modes was observed by means of stereo-microscope (40X magnification), being classified as adhesive, dentin cohesive, resin cohesive and mixed failure. There was no significant difference on the bond strength between the 10s and 20s groups for the majority of the materials. However, both the failure modes and the SEM showed better interaction between dentin and adhesive systems after elapsed 20s its application. It was concluded that longer periods of adhesive system application resulted on better interaction between dentin and adhesive systems evaluated.

Enamel hypoplasia or amelogenesis imperfecta: a restorative approach

Genetic or acquired disturbances may lead to the development of alterations on enamel structure, compromising tooth esthetics and function. This short communication aims to briefly discuss the possibility of employment of several treatment options either to Enamel Hypoplasia or Amelogenesis Imperfecta in order to achieve optimally esthetic results.

Procedimentos adesivos empregados na transformação de dentes conóides e fechamento de diastemas / Direct adhesive procedures employed on peg-shaped teeth transformation and closing diastemata

A demanda estética na Odontologia é gerada pela preocupação da sociedade moderna com a beleza. Os autores apresentam caso clínico que envolve a presença de incisivos laterais superiores conóides, diastemas entre elementos dentais e inversão do sorriso devido ao comprimento inferior dos incisivos centrais em relação aos lateriais. Foi proposta a transformação dental empregando procedimentos adesivos diretos com a associação de hibridização da estrutura dental com resina composta híbrida e micropartícula. Após o planejamento, feito por meio de enceramento em modelo de estudo, foi realizado a transformação dos incisivos laterais conóides, acréscimo na porção incisal dos incisivos centrais e fechamento de diastemas proporcionando harmonia e estética e oclusal do sistema estomatognático

Marginal integrity and microleakage of direct and indirect composite inlays: SEM and stereomicroscopic evaluation

O objetivo deste estudo foi avaliar a microinfiltração em restaurações diretas e indiretas em resina composta por meio de estereomicroscopia e microscopia eletrônica de varredura (MEV). Trinta incisivos bovinos foram lixados de forma a produzir uma plataforma incisal, simulando a face oclusal de um molar humano. Cada dente recebeu dois preparos proximais com 8º e término cervical em esmalte ou dentina. Uma cavidade foi restaurada pela técnica direta com Filtek Z250/Single Bond, e a outra pela técnica indireta com Solidex/RelyX ARC/Single Bond. As amostras foram armazenadas em água a 37°C por 24 horas e então imersas em solução de 50% de nitrato de prata por 6 horas em recipiente escuro. As amostras foram lavadas em água corrente, imersas em solução reveladora e expostas à luz fluorescente por 12 horas. Os dentes foram seccionados para avaliação da penetração do marcador em lupa estereoscópica e MEV. Não houve diferença entre as técnicas direta e indireta para o término em esmalte, porém, para o término em dentina, a técnica indireta resultou em menor infiltração. MEV mostrou infiltração similar à da lupa estereoscópica. A análise por meio de lupa estereoscópica e MEV melhora a avaliação da microinfiltração.

Infiltração marginal em cavidades cervicais: efeito do material de proteção pulpar / Marginal infiltration in cervical cavities: effects pulp liner material

Introdução - Os autores avaliaram a infiltração marginal em cavidades cervicais em 40 pré-molares recém extraídos. Material e métodos - Os materiais utilizados foram divididos em 4 grupos (n= 10): G1 - Vitrebond/A110; G2 - Vidrion R/A110; G3 - Scotchbond Multi-uso/A110; G4 - Single Bond/A110. A análise da infiltração marginal foi realizada por três avaliadores em lupa estereoscópica em aumento de 10x. A infiltração marginal foi sempre superior na margem em dentina que em esmalte. Resultados - O ionômero de vidro convencional como protetor resultou em infiltração estatisticamente superior aos demais grupos. Conclusões - Os demais grupos dos adesivos dentários e o ionômero modificado por resina fotoativado apresentaram comportamentos semelhantes