Preparation and antibacterial properties of Cu-ZnO-loaded dental veneering porcelain / 口腔疾病防治

Objective@#To investigate the antibacterial properties, biocompatibility and mechanical properties of Cu-ZnO-loaded dental veneering porcelain to provide an experimental basis for the development of new dental veneering porcelain. @*Methods@#Cu-ZnO nanoparticles were added to IPS E.max Ceram for restorative veneer porcelain at different mass percentages of 0 wt%, 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5 wt%, and 6 wt% using ball milling in ceramic powder. A cylindrical specimen with a diameter of 20 mm and a thickness of 2 mm was prepared by high-temperature sintering. Scanning electron microscopy was used to observe the surface morphologies of nano-Cu-ZnO and the specimens. The antibacterial effect of Escherichia coli (E. coli) was quantitatively studied by the plate colony counting method. The CCK-8 method was used to evaluate in vitro the cytotoxicity of the tested piece to mouse fibroblasts (L929). Live and dead cells were observed by fluorescence microscopy. The mechanical properties of modified IPS E. Max Ceram veneering porcelain were tested by a three-point bending strength test. @* Results @# Under the scanning electron microscope, Cu-ZnO appears with a block-like structure and can be seen dispersed in the veneering porcelain. When the nano Cu-ZnO loading was 1 wt%, 2 wt%, 3 wt%, and 4 wt%, the antibacterial rates of the specimens were 24.85%, 67.94%, 96.92%, and 99.99%, respectively, and the difference between the experimental groups and the control group was statistically significant (F = 23.308,P = 0.001). The relative growth rate of each group was greater than 80% after coculture with mouse fibroblast cells (L929) for 1 day and 3 days, and there was no significant difference between the groups. The morphology of L929 cells was normal after coculture for 24 hours. With the increase in the Cu-ZnO concentration, the flexural strength of the specimen exhibited an increasing trend followed by a decreasing trend. The bending strength of the specimen loaded with 3 wt% nano Cu-ZnO reached the maximum value (84.728 ± 6.82) MPa, and there was no statistically significant difference between groups (F = 0.633,P = 0.702).@*Conclusion@#The antibacterial rate of IPS E. max Ceram veneering porcelain loaded with 3 wt% nano Cu-ZnO was more than 96% against E. coli after high-temperature sintering at 750 ℃. The bending strength reached the maximum (84.728 ± 6.82) MPa, and there was no obvious cytotoxicity.

Influence of diode laser and warm air drying on the shear bond strength of Lithium di-silicate to Dentin. An in-vitro study / Influência do laser de diodo e da secagem com ar quente na resistência ao cisalhamento do Di-silicato de Lítio a dentina. Um estudo in-vitro

Objective: The current study aimed to evaluate the effect of diode laser irradiation (980 nm) and warm air drying (50°C) on shear bond strength between Lithium di-silicate (IPS e.max; Ivoclar) and human dentin using both (Etch & Rinse) adhesive, Adper™ Single Bond 2 (3M ESPE) and (Self-etch) adhesive, Single Bond UniversalTM(3M ESPE) before adhesive polymerization. Material and Methods: 54 sound lower molars were sectioned to obtain flat dentinal surfaces. Specimens were divided into 2 equal groups (n=27): Group 1 (ER) and Group 2 (SE) according to bonding approach. Each subgroup was subdivided according to dentin surface treatment into 3 equal subgroups (n=9): Control (Co), Diode laser irradiation (L) and Warm air drying (W). All specimens were adhesively cemented to IPS e.max® CAD discs using RelyX™ Ultimate Clicker™(3M ESPE) resin cement. Samples were then subjected to pre-loading in a thermodynamic manner. All samples were tested for shear bond strength using computer-controlled material testing machine. Data analysis was performed using two-way (ANOVA) (p< 0.05) followed by pair-wise Tukey's post-hoc tests. Results: In (SE) group, the subgroup (W) had the highest shear bond strength values followed by (Co) subgroup and the least was (L) subgroup with statistically significant difference. As for (ER) group, the subgroup (W) had the highest shear bond strength values followed by (Co) subgroup and the least was (L) subgroup with no statistically significant difference. Conclusion: Warm air drying for (SE) bonding approach increased shear bond strength of Lithium di-silicate to human dentin and can be introduced as a new effective protocol.(AU)

Objetivo: o objetivo do estudo atual é avaliar o efeito da radiação do laser de diodo (980nm) e secagem de ar quente (50°C) na resistência ao cisalhamento entre dissilicati de Lítio (IPS e.max; Ivoclar) e a dentina humana usando ambos modelos de adesivos (condicionamento total) Adper™ Single Bond e (auto-condicionante) Single Bond Universal™ (3M ESPE), Single Bond UniversalTM (3M ESPE) antes da fotopolimerização. Material e Métodos: 54 segundos molares inferiores foram selecionados para obter superfícies dentinárias planas. Os espécimes foram divididos em 2 grupos iguais (n=27): grupo 1 (ER) e grupo 2 (SE) de acordo com protocolo de adesividade. Cada grupo foi subdividido de acordo com o tratamento de superfície dentro de 3 subgrupos iguais (n=9): Controle (co), irradiação com laser de diodo (L) e secagem com ar quente (W). Todos os espécimes foram adesivamente cimentados a discos de IPS emax CAD usando RelyX Ultimate Clicker (3M ESPE) cimento resinoso. As amostras foram então submetidas a pré-carregamento de forma termodinâmica. Todas as amostras foram testadas para resistência a cisalhamento usando máquina de teste de materiais controlados por computador. A análise de dados foi realizada usando ANOVA dois fatores (p<0.05) seguindo por testes de Tukey pareado como test post-hoc. Resultados: No grupo (SE), o subgrupo (W) apresentou maiores valores de resistência ao cisalhamento seguindo o subgrupo (Co) é o menor foi o subgrupo (L) com diferença estatisticamente significativa. Já para o grupo (Er), o subgrupo (W) apresentou os maiores valores de resistência ao cisalhamento seguido do grupo (Co) e o menor foi o subgrupo (L) sem diferença estatisticamente significante. Conclusão: a secagem com ar quente para a abordagem de adesividade (Se) aumentou a resistência ao cisalhamento do dissilicato de lítio à dentina humana e poderia ser introduzido como um novo e eficaz protocolo(AU)

One year clinical evaluation of e-max press crowns retained with fiber reinforced composite post versus e-max press endocrowns in anterior endodontically treated teeth (a randomized clinical trial) / Avaliação clínica de um ano de coroas e-max retidas com resina composta reforçada por fibra versus endocrowns de e-max em dentes anteriores tratados endodonticamente: um ensaio clínico randomizado

Objective: The purpose of this study was to assess patient satisfaction, gross fracture and marginal adaptation of e.max press endocrowns versus e.max press crowns retained with Fiber reinforced composite post (FRCP) and core in upper anterior teeth. Material and methods: The present study included 24 patients seeking root canal treatment in anterior upper arch. The patients received root canal treatment (RCT) then they were randomly assigned into two groups (n=12). The first group received preparation for the IPS e.max crowns retained with FRCP and core and the second group received preparation for the IPS e.max endocrowns. Press technique was used for the fabrication of both restorations using IPS e.max press ingots. Marginal integrity and gross fracture were evaluated using USPHS criteria and a questionnaire was conducted to evaluate patient satisfaction. Data were analyzed using IBM SPSS Statistics for Windows, Version 23.0. Armonk, NY: IBM Corp. Results: There was no statistical significant difference regarding gross fracture of both groups after 12 months (p-value = 0.093, Effect size = 0.447), meanwhile; group 1 was statistically significantly higher than group 2 regarding marginal integrity (p-value = 0.037, Effect size = 0.513). Regarding patient satisfaction FRCP and core group showed statistical significant higher satisfaction than endocrown group (p-value = 0.047, Effect size = 0.447). Conclusion: E.max press endocrowns revealed successful performance similar to e.max press crowns retained with FRCP in terms of gross fracture, however better marginal adaptation and patient satisfaction was obtained with e.max press crowns retained with FRC post and core group. (AU)

Objetivo: O objetivo deste estudo foi avaliar a satisfação do paciente, grau de fratura grosseira e adaptação marginal de endocrowns e.max versus coroas de e.max retidas com pino de compósito reforçado com fibra (FRCP) e núcleo nos dentes anteriores superiores. Material e métodos: O presente estudo incluiu 24 pacientes que buscavam tratamento endodôntico na arcada superior anterior. Os pacientes receberam tratamento de canal radicular (RCT) e foram divididos aleatoriamente em dois grupos (n = 12). O primeiro grupo recebeu preparação para as coroas IPS e.max retidas com FRCP e núcleo e o segundo grupo recebeu preparos para as endocrowns IPS e.max. A técnica de prensagem foi usada para a fabricação de ambas as restaurações usando os lingotes de prensagem IPS e.max. A integridade marginal e a fratura macroscópica foram avaliadas usando os critérios da USPHS e um questionário foi realizado para avaliar a satisfação do paciente. Os dados foram analisados usando IBM SPSS Statistics for Windows, versão 23.0. Armonk, NY: IBM Corp. Resultados: Não houve diferença estatisticamente significativa em relação à fratura bruta de ambos os grupos após 12 meses (p-valor = 0,093, tamanho do efeito = 0,447), entretanto; o grupo 1 foi estatisticamente significativamente maior do que o grupo 2 em relação à integridade marginal (p-valor = 0,037, tamanho do efeito = 0,513). Em relação à satisfação do paciente, o FRCP e o grupo principal mostraram maior satisfação estatisticamente significativa do que o grupo endocrown (p-valor = 0,047, tamanho do efeito = 0,447). Conclusão: as endocrowns E.max press revelaram um desempenho bem-sucedido semelhante às coroas e.max press retidas com FRCP em termos de fratura bruta, no entanto, melhor adaptação marginal e satisfação do paciente foram obtidas com as coroas e.max press retidas com pilar FRC e núcleo de preenchimento (AU)

Mechanical and thermal stress analysis of hybrid ceramic and lithium disilicate based ceramic CAD-CAM inlays using 3-D finite element analysis / Análise do estresse mecânico e térmico de inlays de cerâmica hibrida e de cerâmica a base de dissilicato de lítio através da análise em 3D de elementos finitos

Objective: The aim of this study was to analyze mechanical and thermal stresses of hybrid ceramic and lithium disilicate based ceramic of CAD/CAM inlays using 3D Finite element analysis. Material and Methods:A three dimensions finite element model of permanent maxillary premolar designed according to standard anatomy with class II cavity preparation for inlay restored with two different ceramic materials: 1- Hybrid ceramic (Vita Enamic), 2- Lithium disilicate based ceramic (IPS e.max CAD). Totally six runs were performed on the model as: One loading case for each restorative material was tested in stress analysis; seven points of loading with 140N vertically applied at palatal cusp tip and cusp slop, marginal ridges and central fossa while the models base was fixed as a boundary condition in the two cases. Two thermal analysis cases were performed for each restoration material by applying 5ºC and 55ºC on the crown surface including the restoration surface. Results:The results of all structures were separated from the rest of the model to analyze the magnitude of stress in each component. For each group, maximum stresses on restorative materials, cement, enamel, and dentin were evaluated separately. Both ceramic materials generated similar stress distribution patterns for all groups when a total occlusal load of 140 N was applied. Conclusion: Thermal fluctuations of temperature have a great influence on the stresses induced on both restoration and tooth structure. IPS e.max CAD produced more favorable stresses on the tooth structure than Vita Enamic. (AU)

Objetivo: O objetivo deste estudo foi analisar o estresse mecânico e térmico de inlays de cerâmica hibrida e a base de dissilicato de lítio através da análise em 3D de elementos finitos. Material e Métodos: Foi realizado o design de um modelo de três dimensões em elementos finitos de um pré-molar superior de acordo com os padrões anatômicos de um preparo de cavidade classe II para restauração de inlay em dois tipos de cerâmicas diferentes: 1 Cerâmica hibrida (Vita Enamic), 2 ­ Cerâmica a base de dissilicato de lítio (IPS e.max CAD). No total, seis execuções foram realizadas no modelo como: Uma carga para cada material restaurador foi testado para análise de tensão; sete pontos de carga com 140N foi aplicado verticalmente na ponta da cúspide palatina, saliência da cúspide, cristas marginais e fossa central enquanto a base do modelo foi fixada como uma condição de limite nos dois casos. Duas análises térmicas foram realizadas para cada material de restauração, aplicando 5ºC e 55ºC na superfície da coroa, incluindo a superfície da restauração. Resultados: Os resultados de todas as estruturas foram separados do resto do modelo para analisar a magnitude do estresse de cada componente. Para cada grupo, o máximo de estresse nos materiais restauradores, cemento, esmalte e dentina foram avaliados separadamente. Padrões similares de distribuição de estresse foram gerados em todos os grupos para ambos os materiais cerâmicos, quando a carga oclusal de 140 N foi aplicada. Conclusão: As variações térmicas de temperatura têm uma grande influência nas tensões induzidas na restauração e na estrutura dentária. IPS e.max CAD produziu tensões mais favoráveis na estrutura dentária do que o Vita Enamic (AU)

Evaluation of biocompatibility of veneered Bio HPP and veneered lithium disilicate crowns in anterior zone (Randomized controlled clinical trial) / Avaliação da biocompatibilidade de coroas de Bio HPP e coroas de dissilicato de lítio na região anterior (ensaio clínico controlado randomizado)

Objective: Evaluation of the biocompatibility of Bio-High Performance Polymer (Bio HPP) crowns veneered with Visio-Ling versus e.max crowns veneered with e.max veneering system. Material and Methods: 42 full-coverage crowns were fabricated for maxillary anterior teeth. A swap was obtained using a sterile paper cone to determine bacterial count and type. Pocket depth (PD) was determined using a William Periodontal probe. Measurements were repeated after 3, 6, 9 and 12 months respectively. Patients were randomly divided into: Group A fabricated from IPS e.max crowns and Group B fabricated from Bio HPP crowns. The preparations were standardized with an equi-gingival, finish line. Fisher's test was used to compare between the two groups. The significance level was set at P ≤ 0.05. Statistical analysis was performed with Windows, Version 23.0. (IBM SPSS Statistics) Armonk, NY: IBM Corp. Results: Bio HPP and e.max showed no statistically significant difference in bleeding on probing and PD except after 9and 12 months; Bio HPP showed statistically significantly higher PD than e.max (P-value = 0.027, Effect size = 0.245) and (P-value = 0.011, Effect size = 0.310), respectively. Fisher's test showed there was no statistically significant difference between total bacterial counts and the type of the two materials. Conclusion: Both e.max and Bio HPP crowns revealed successful biological behavior. No significant difference between the materials regarding the bacterial count and type as well as the pocket depth, however after 9 and 12 months, Bio HPP showed a higher significant difference PD than e.max. (AU)

Objetivo: Avaliação da biocompatibilidade de coroas de Polímero Bio-High Performance (Bio HPP) estratificadas com Visio-Ling versus coroas e.max estratificadas com sistema de estratificação e.max. Material e Métodos: 42 coroas totais foram confeccionadas para dentes anteriores superiores. Uma amostra foi obtida usando um cone de papel estéril para determinar a contagem e o tipo de bactérias. A profundidade de bolsa (PD) foi determinada usando uma sonda periodontal de William. As medições foram repetidas após 3, 6, 9 e 12 meses, respectivamente. Os pacientes foram divididos aleatoriamente em: Grupo A fabricado com coroas IPS e.max e Grupo B fabricado com coroas Bio HPP. As preparações foram padronizadas com uma linha de término no nível da gengiva marginal. O teste de Fisher foi usado para comparação entre os dois grupos. O nível de significância foi estabelecido em P ≤ 0,05. A análise estatística foi realizada com Windows, versão 23.0. (IBM SPSS Statistics) Armonk, NY: IBM Corp. Resultados: Bio HPP e e.max não mostraram nenhuma diferença estatisticamente significativa no sangramento à sondagem e PD, exceto após 9 e 12 meses; Bio HPP mostrou PD estatisticamente significativa maior do que e.max (valor P = 0,027, tamanho do efeito = 0,245) e (valor P = 0,011, tamanho do efeito = 0,310), respectivamente. O teste de Fisher mostrou que não houve diferença estatisticamente significativa entre as contagens bacterianas totais e o tipo dos dois materiais. Conclusão: As coroas e.max e Bio HPP revelaram comportamento biológico bem-sucedidos. Não houve diferença significativa entre os materiais em relação à contagem e tipo de bactérias, bem como à profundidade da bolsa, no entanto, após 9 e 12 meses, o Bio HPP apresentou uma diferença significativamente mais elevada de PD do que e.max. (AU)

An assessment of color effect on minimal and no-preparation veneers / 实用口腔医学杂志

Objective: To evaluate the color effect of esthetic rehabilitation of anterior teeth restored with the minimal and no-preparation veneers and to analyze the influence factors of satisfaction. Methods: 30 patients were divided into group A (9 patients with tetracycline discoloured teeth treated with 72 veneers) and group B (21 patients with non-tetracycline teeth treated with 66 veneers) . All the selected teeth were restored with the minimal and non-preparation veneers. Before the teeth were prepared and after veneers were cemented, Olympus Crystaleye was employed to obtain L*, a*, b*values of each tooth. The shade was selected according to the patients' expectation and dentist's advice. The color difference (ΔE) before and after restoration of group A and group B, the color difference (ΔE1) between the tooth color after restoration and the expectation color of the patients, the relationship of the satisfaction degree and the color difference (ΔE1), the lightness difference (ΔL*), Δa*and Δb*were analyzed by SPSS 20. 0. Results: After cemented, the color of teeth-veneer-complex obviously improved in both groups. The color difference (ΔE1) between the tooth color before and after restoration, and the expected color between the 2 group was significant (P ＜ 0. 05) . ΔE1, ΔL*, Δa*had great influence on the satisfaction of dentists and patients (P ＜ 0. 05) . Conclusion: The appearance of non-tetracycline teeth restored with the minimal and no-preparation veneers was excellent. The more of the color of the teeth-veneer-complex matched the expectation color, the higher the patients are satisfied with the restorations. The less of the lightness difference, the higher the patients are satisfied with the restorations.

Alternativas de tratamientos de superficie para adhesión de cerámica de disilicado de litio / Alternatives of surface treatments for adhesion of lithium disilicate ceramics

Introduction: the clinical success of a restoration is strongly associated with the quality and durability of the ceramic-cement resin interface. In order to obtain an adequate union between these materials of different nature surface treatments are used and achieve mechanical retention or chemical interaction. Objectives: to check if any method promotes a true chemical bond between lithium disilicate ceramics and resin cement. As well as determineif there is any treatment that reports bonding values comparable to hydrofluoric acid and silane (gold standard). Methods: a systematic literature review was developed based on the PRISMA strategy, where the databases were searched: Science Direct, Pubmed (MEDLINE), EMBASE, Springer Journal, SciELO with MeSH and free terms from 2005 to November 2016 for articles in English and Spanish on surface treatments for lithium disilicate. Results: from 58 publications selected a sample of 21 articles. Two articles reported high risk of bias. Conclusions: hydrofluoric acid and silane continue to be the method with the highest and most reliable adhesion values in the literature. Universal adhesives are an alternative to promote chemical adhesion additional to the silane. Diamond burs, Nd: YAG and Er: YAG laser are not recommended as surface treatments(AU)

Introducción: el éxito clínico de una restauración se asocia fuertemente a la calidad y duración de la interface cerámica-cemento resinoso. Para que exista una adecuada unión entre estos materiales de distinta naturaleza se emplean tratamientos de superficie para lograr una buena retención mecánica o interacción química. Objetivos: revisar si algún método promueve una verdadera adhesión química entre la cerámica de disilicato de litio y el cemento resinoso, así como determinar si existe algún tratamiento que reporte valores de unión comparables al ácido fluorhídrico y silano (patrón de oro). Métodos: se desarrolló una revisión sistemática de literatura basada en la estrategia PRISMA, donde se buscó en las bases de datos: Science Direct, Pubmed (MEDLINE), EMBASE, Springer Journal, SciELO con términos MeSH y libres desde el 2005 a noviembre de 2016 para artículos en inglés y español sobre tratamientos de superficie para disilicato de litio. Resultados: de 58 publicaciones, se seleccionó una muestra de 21 artículos. Dos artículos reportaron riesgo de sesgo alto. Conclusiones: el ácido fluorhídrico y silano continúan siendo el método con los valores de adhesión más altos y confiables de la literatura. Los adhesivos universales son una alternativa para promover adhesión química adicional al silano. Fresas diamantadas, laser Nd: YAG y Er:YAG no se recomienda como tratamientos de superficie(AU)

Effect of different hydrofluoric acid etching methods on the surface and adhesion strength of two ceramic inlays / 口腔疾病防治

Objective@#o study the effect of cleaning treatment with hydrofluoric acid (HF) on the surface and bonding strength of IPS e.max and Vita Mark II ceramic inlays. @*Methods@#Fifty pieces of IPS e.max and Vita Mark II ceramic inlay specimens were made separately using CAD/CAM. After uniformly bonding surfaces using 9% HF etching, they were randomly divided into an untreated control group (group A) and the following experimental groups: neutralizing powder (B group), 37% phosphoric acid (group C), ultrasonic cleaning (group D) and neutralizing powder + 37% phosphoric acid + ultrasonic cleaning (group E). Each set of 8 specimens was bonded to Variolink N resin adhesive under standard conditions. The shear adhesive strength was measured after exposure to a constant-temperature water bath at 37 ℃ for 24 h. The location of the fracture and the type of adhesion failure were recorded. The shear adhesion and the average strength of the connection were analyzed. The remaining 2 specimens were used for scanning electron microscopy (SEM) to observe the surface morphology, including the crystal structure, pore pattern, and residue.@*Results @# The results were similar for the IPS e.max and Vita Mark II inlays. The maximum bond strength was observed in the IPS e.max ceramic inlays in group E, with an average bond strength 11.96 MPa higher than that in group A. Among the Vita Mark II porcelain inlays, the maximum bond strength was observed in group E. The average bond strength was 9.74 MPa higher than that in group A. The results of the statistical analysis were similar for the IPS e.max and Vita Mark II porcelain inlays, with significant differences in the bond strengths between groups C, D, and E and the control group (P < 0.05). There was no significant difference in the adhesive strength between groups B and A. At the same time, there was no significant difference in the bond strength between the treatment groups B, C, D, and E (P > 0.05). SEM revealed that the pores on the surface of ceramics subjected to the acid etching treatment were broadened and uniform, with less residue than observed in the control group. The effects of treatments D and E were the best. @*Conclusion@#The HF etching treatment can enhance the bonding strength of IPS e.max and Vita Mark Ⅱ ceramic inlays while leaving little residue, and the joint strength is highest when the joints are treated together.

The effect of Er: YAG laser irradiation on bonding properties of IPS e.max CAD ceramics / 口腔疾病防治

Objective @#To investigate different Er:YAG laser power settings on the bonding properties of IPS e.max CAD ceramics. @*Methods@# 96 IPS e.max CAD ceramics blocks (5 mm × 5 mm × 5 mm) were prepared and randomly divided into 8 groups (n = 12), the untreated blocks served as the control, while one of the experimental groups was treated with 4.5% HF for 20 seconds, six remaining test group (C、D、E、F、G、H) were treated with different Er: YAG laser power settings: 100 mJ、200 mJ、300 mJ、400 mJ、500 mJ and 600 mJ. Morphology of the ceramic surface was observed by atomic force microscopy and its shear bond strength (SBS) was tested. @*Results @#Higher shear bond strength values were found in group C-H compared to group B, the highest is group F (24.12 ± 1.91) MPa. The difference was statistically significant. The atomic force microscope observation of the surface structure showed that the control group was smooth and flat, and the HF-like etching group formed a uniform needle-like convex structure. The laser group gradually formed a regularly arranged cylindrical convex structure, in which the surface of the G and H groups was damaged. @*Conclusion @#The Er: YAG laser power settings of 400 mJ can be used as an effective pretreatment method before bonding of IPS e.max CAD ceramic.

Clinical effects of full crown prosthesis on anterior teeth / 中华医学美学美容杂志

Objective To evaluate the clinical effects of anterior teeth repair of three different restorations made of Co-Cr alloy,Ag-Pd alloy and all-ceramic crowns.Methods 90 cases who needed the both maxillary and mandibular anterior teeth restarations were selected and treated respectively with Co-Cr alloy porcelain fused to metal crowns (PFM)(60 teeth),Ag-Pd alloy PFM (46 teeth)and IPS e.max Press Porcelain full crown (38 teeth).Gingival index was observed before restoration and in 6 and 12 months after restoration.Meanwhile,clinical indicators of two restorations were evaluated as cervical margin's coloration,margin fitness degree,color of restorations,fracture of restorations and contour of restorations,etc.Results The healthy condition of gingiva in groups of Ag-Pd alloy PFM and IPS e.max Press Porcelain full crown were superior to the group of Co-Cr alloy PFM (P＜0.05).There was no cervical margin's coloration in groug of all-ceramic PFM.The color and contour of this group was superior to the group of Co-Cr alloy PFM (P ＜0.05).The significant difference between group of Co Cr alloy and group of Ag-Pd alloy was cervical margin's coloration and marginal density of the restoration (P＜0.05).Conclusions The clinical effects of both groups of Ag-Pd alloy PFM and IPS e.max Press Porcelain full crown is superior to the group of Co-Cr alloy PFM.The IPS e.max Press Porcelain full crown group works best.

Population pharmacodynamics of cilostazol in healthy Korean subjects

Cilostazol is used for the treatment of intermittent claudication, ulceration and pain. This study was conducted to develop a population pharmacodynamic (PD) model for cilostazol's closure time (CT) prolongation effect in healthy Korean subjects based on a pharmacokinetic (PK) model previously developed. PD data were obtained from 29 healthy subjects who participated in a study conducted in 2009 at Severance Hospital. The PK model used was a two-compartment model with first order absorption. CT data were best described by a turnover model with a fractional turnover rate constant (K(out)) inhibited by drug effects (Eff), which were represented by a sigmoid E(max) model [Eff = E(max) · C(γ) / (EC₅₀(γ)+C(γ))] with E(max) being maximum drug effect, EC₅₀ drug plasma concentration at 50% of E(max), C drug plasma concentrations, and γ the Hill coefficient. For the selected PD model, parameter estimates were 0.613 hr⁻¹ for K(out), 0.192 for E(max), 730 ng/ml for EC₅₀ and 5.137 for γ. Sex and caffeine drinking status significantly influenced the baseline CT, which was 85.36 seconds in male non-caffeine drinkers and increased by 15.5% and 16.4% in females and caffeine drinkers, respectively. The model adequately described the time course of CT. This was the first population PD study for cilostazol's CT prolongation effect in a Korean population.

The effect of Er: YAG laser irradiation on bonding properties of IPS e.max CAD ceramics / 口腔疾病防治

Objective@#To investigate different Er:YAG laser power settings on the bonding properties of IPS e.max CAD ceramics. @*Methods @# 96 IPS e.max CAD ceramics blocks (5 mm × 5 mm × 5 mm) were prepared and randomly divided into 8 groups (n = 12), the untreated blocks served as the control, while one of the experimental groups was treated with 4.5% HF for 20 seconds, six remaining test group (C、D、E、F、G、H) were treated with different Er: YAG laser power settings: 100 mJ、200 mJ、300 mJ、400 mJ、500 mJ and 600 mJ. Morphology of the ceramic surface was observed by atomic force microscopy and its shear bond strength (SBS) was tested. @*Results @#Higher shear bond strength values were found in group C-H compared to group B, the highest is group F (24.12 ± 1.91) MPa. The difference was statistically significant. The atomic force microscope observation of the surface structure showed that the control group was smooth and flat, and the HF-like etching group formed a uniform needle-like convex structure. The laser group gradually formed a regularly arranged cylindrical convex structure, in which the surface of the G and H groups was damaged. @*Conclusion@# The Er: YAG laser power settings of 400 mJ can be used as an effective pretreatment method before bonding of IPS e.max CAD ceramic.

Parameter estimation for sigmoid E(max) models in exposure-response relationship

The purpose of this simulation study is to explore the limitation of the population PK/PD analysis using data from a clinical study and to help to construct an appropriate PK/PD design that enable precise and unbiased estimation of both fixed and random PD parameters in PK/PD analysis under different doses and Hill coefficients. Seven escalating doses of virtual drugs with equal potency and efficacy but with five different Hill coefficients were used in simulations of single and multiple dose scenarios with dense sampling design. A total of 70 scenarios with 100 subjects were simulated and estimated 100 times applying 1-compartment PK model and sigmoid E(max) model. The bias and precision of the parameter estimates in each scenario were assessed using relative bias and relative root mean square error. For the single dose scenarios, most PD parameters of sigmoid E(max) model were accurately and precisely estimated when the C(max) was more than 85% of EC₅₀, except for typical value and inter-individual variability of EC₅₀ which were poorly estimated at low Hill coefficients. For the multiple dose studies, the parameter estimation performance was not good. This simulation study demonstrated the effect of the relative range of sampled concentrations to EC₅₀ and sigmoidicity on the parameter estimation performance using dense sampling design.

Clinical application of E-MAX glass ceramic onlays in the restorations of the nonvital posterior teeth / 口腔疾病防治

Objective @# To investigate the clinical use of glass ceramic onlay in the restoration of the non-vital posterior teeth with computer aided design and computer-aided manufacturing technique (CAD/CAM). @*Methods @# 70 patients with 75 teeth of residual crown were selected and restored with CAD/CAM glass-ceramic onlay after completely root canal therapy. Marginal adaptation, anatomic form, adjacent relation, contour appearance, color match were checked in 12-month follow-up. @*Results @# Marginal adaptation, anatomic form, adjacent relation, contour appearance, color match of 73 teeth were satisfactory and 2 cases was excluded because of lost to follow-up. There were no significant differences in the number of cases which met clinical criterion A or B between immediate restoration and 12-month follow-up (P > 0.05), and more than 95% of cases met clinical criterion A.@*Conclusion @#The CAD/CAM glass-ceramic onlay in the restoration of non-vital posterior teeth can provide better effect of retention and esthetics in a short term observation of 12 months.

In vitro study of wear of Ceramage and IPS e.max Press / 口腔疾病防治

Objective @#To compare the wear of Ceramage and IPS e.max Press offering foundation for nonmetallic materials selection in clinical. @*Methods @#20 class I cavities were prepared in the approximal flattened sides of the extracted human maxillary first molars. The cavities were divided into 2 groups randomly, and then restored with Ceramage or IPS e.max Press. Inlays were prepared according to the manufactures’ instructions with indirect methods and cemented with Varolink N. The non-wear extracted maxillary third molars were used as antagonistic enamel cusps after standardized prepared. After the self-made wear-testing device concluded 200,000 cycles under a load of 20 N, the wear depth of specimens and antagonistic enamel cusps was assessed by Kavo PREP assistant.@*Results @# The wear in Ceramage group was (298.30 ± 40.02) μm, while the wear of normal enamel was (206.60 ± 49.17) μm. The wear in IPS e.max Press group was (212.90 ± 61.21) μm, while the wear of normal enamel was (217.00 ± 25.10) μm. The wear of IPS e.max Press inlays was higher than Ceramage inlays (P < 0.05). Ceramage inlays showed higher wear than normal enamel (P < 0.05), while IPS e.max Press inlays was not statistically different from the normal enamel (P > 0.05). @*Conclusions @#Ceramage has more wear than IPS e.max Press. Ceramage shows higher wear compared with normal enamel, while IPS e.max Press has lower antagonistic war compared with normal enamel.

The Effect of Lithium Disilicate Glass-Ceramic Core Thickness on Fracture Thickness of All-ceramic Restorations.

Statement of the Problem: Fracture strength is fundamental for the long-term success and clinical service of all-ceramic restorations. Core thickness is an important factor affecting fracture strength. Purpose: The main objective of this study was to assess and compare the fracture strength of 0.4 mm and 0.7 mm core thicknesses. Materials and Methods: In this in vitro, experimental study, one brass die was prepared with classic chamfer finish line design (0.8 mm depth). An impression was made from the metal die and poured with epoxy resin. The epoxy resin die was scanned and lithium disilicate glass ceramic core was fabricated by the computer-aided design/computer-aided manufacturing (CAD/CAM) technique. IPS e.max cores with 0.4 and 0.7 mm thicknesses were fabricated using CAD/CAM technique. Ten samples were fabricated of each thickness and veneered with IPS e.max. After adhesive bonding onto the die, they were vertically loaded using a universal testing machine until fracture. The data were statistically analyzed using the Kolmogorov-Smirnov test and t-test. Results: The mean and standard deviation (SD) of fracture strength were 1754±313.47 and 1073±202.81 N, for 0.7 mm and 0.4 mm cores, respectively. The Kolmogorov-Smirnov test showed normal distribution of data; thus, t-test was applied for comparison of the two groups (p<0.001). The fracture strength of 0.7 mm core was significantly greater than that of 0.4 mm core. Conclusions: Within the limitations of this study, it was concluded that increasing the core thickness improves the fracture strength. However, the mean fracture strength values obtained for 0.4 and 0.7 mm core thicknesses were far greater than the load threshold applied in the oral cavity; thus, both thicknesses can be successfully used in the clinical setting.

Comparación In Vitro de la adaptación marginal entre incrustaciones MOD maquinadas con el sistema IPS e: max CAD y restauraciones MOD en oro colado tipo III / valuation of marginal adaptation In Vitro of MOD fillings with an enamel finish manufactured with IPS e: max CAD (computer assisted design) and with gold type III

Objetivo: comparar la adaptación marginal In Vitro de incrustaciones MOD con terminación en esmalte fabricadas con IPS e.max CAD (Computer Asisted Desing) y fabricadas en oro tipo III. Materiales y métodos: En este estudio experimental exploratorio se uso una muestra no probabilística de 15 premolares sanos por cada uno de los dos grupos; IPS e.max CAD y oro tipo III.A todos los premolares se les realizó cavidades MOD estandarizadas para los 2 grupos. Los dientes preparados fueron asignados aleatoriamente a cada grupo. Las incrustaciones del grupo IPS e.max CAD fueron elaboradas con el sistema CEREC 3 y las incrustaciones en oro fueron elaboradas por los investigadores. Se tomaron estereo microfotografías de todas las muestras sobre papel milimetrado, y las imágenes fueron analizadas mediante el programa ImageTool. Se tomaron tres medidas adaptación marginal en el área proximal mesial o distal de cada muestra, que fueron promediadas y reportadas en micras. Los datos fueron analizados mediante ANOVA y Test de Mann-Whitney. Resultados: el 98% del total de las incrustaciones en oro y el 47% del total de las incrustaciones de IPS e.max CAD presentaron una adaptación marginal < a 120 micras. El promedio de desadaptación marginal del grupo IPS e.max CAD fue 122.8 μ + 44.1, mientras que para el grupo oro fue de 75.3 μ+42,6 encontrándose diferencias estadísticamente significativas entre los dos. Conclusiones: El oro reporta mejor adaptación marginal en restauraciones inlays MOD que los sistemas maquinados como el sistema IPS e.max CAD.

Objective: To compare In Vitro, the marginal adaptation of MOD fillings with an enamel finish manufactured with IPS e.max CAD (Computer Assisted Design) and those manufactured with gold type III. Materials and methods: In this exploratory experimental study, a non-probabilistic sample of 15 healthy premolars for each of the two groups (IPS e.max CAD and gold type III) was used. Standardized MOD cavities were made in all the premolars for both groups. The prepared teeth were randomly assigned to each group. The IPS e.max CAD fillings were made using the CEREC 3 system and the gold fillings were made by the researchers. Stereo microphotographs of all the samples were taken on millimeter paper and the images were analyzed using the Image Tool software. Three marginal adaptation measurements in the mesial proximal or distal area were taken for every sample; they were averaged and reported in microns. The data was analyzed using ANOVA and the Mann-Whitney test. Results: 98% of all the gold fillings and 47% of all the IPS e.max CAD fillings showed a marginal adaptation of less than or equal to 120 microns. The marginal unfitness average for the IPD e.max CAD group was 122.8 + 44.1 μm, and for the gold fillings group it was 75.3 + 42.6 μm. There was a statistically significant differences between the groups. Conclusions: Gold reports a better marginal adaptation for inlay MOD fillings than manufactured systems like IPS e.max CAD system.

Assessment of clinical effect of IPS e. max press ceramic endocrowns in preserving endodontically treated molars / 中华医学美学美容杂志

Objective To evaluate the clinical effect of IPSe. max press ceramic endocrowns being used in preserving endodontically treated molars. Methods Forty-five endodontically treated molars were selected from 45 patients in this study. All the molars had been endodontically treated and performed with ultrasonic scaling. After 1-2 weeks, the crowns and pulp chambers were prepared. The impressions and master casts were gained and IPSe. max press ceramic endocrowns were fabricated in the lab. The endocrowns were cemented with resin cement. The further consultations were offered to these molars after 6 months and 1 year. The difference of sulcus bleeding index among these endodontically treated molars and the same teeth in the opposite sides was compared. Results In these cases, 100 % of endocrowns were

An in-vitro wear study of human enamel opposing heat-pressed ceramics / 대한치과보철학회지

PURPOSE: The purpose of this study was to compare the wear characteristics of human enamel opposing 2 heat-pressed ceramics (e.max Press and Empress Esthetic), conventional feldspathic porcelain (Ceramco 3) and type III gold alloy. MATERIAL AND METHODS: Intact cusps of extracted premolars were used for enamel specimens. Five disk samples were made for each of two heat-pressed ceramics groups, conventional feldspathic porcelain group and type III gold alloy group. Wear tests were conducted in distilled water using a pin-on-disk tribometer. The amount of enamel wear was determined by weighing the enamel specimens before and after wear tests, and the weight was converted to volumes by average density. The wear tracks were analyzed by scanning electron microscopy and surface profilometer to elucidate the wear characteristics. RESULTS: 1. Ceramco 3 led to the greatest amount of enamel wear followed by Empress Esthetic, e.max Press and type III gold alloy. However, there was no significant difference between Ceramco 3 and Empress Esthetic (P > .05), and there were also no significant differences among Empress Esthetic, e.max Press and type III gold alloy (P > .05). 2. The average surface roughness of e.max Press after wear test was smallest followed by Empress Esthetic and Ceramco 3, but there was no significant difference between Empress Esthetic and Ceramco 3 (P > .05). 3. There were no significant differences among the depth of wear tracks of all the groups (P > .05). The group that showed the largest width of wear track was Ceramco 3 followed by Empress Esthetic, e.max Press and type III gold alloy. However, there was no significant difference between e.max Press and Empress Esthetic (P > .05), and there was also no significant difference between Empress Esthetic and Ceramco 3 (P > .05). CONCLUSION: Within the limits of this study, heat-pressed ceramics were not more abrasive than conventional feldspathic porcelain.

Improvement in Regional Contractility of Myocardium after CABG / 대한핵의학회잡지

PURPOSE: The maximal elastance (E (max) ) of myocardium has been established as a reliable load-independent contractility index. Recently, we developed a noninvasive method to measure the regional contractility using gated myocardial SPECT and arterial tonometry data. In this study, we measured regional E (max) (rE (max) ) in the patients who underwent coronary artery bypass graft surgery (CABG), and assessed its relationship with other variables. MATERIALS AND METHODS: 21 patients (M: F=17: 4, 58+/-12 y) who underwent CABG were enrolled. (201) Tl rest/ dipyridamole stress (99m) Tc-sestamibi gated SPECT were performed before and 3 months after CABG. For 15 myocardial regions, regional time-elastance curve was obtained using the pressure data of tonometry and the volume data of gated SPECT. To investigate the coupling with myocardial function, preoperative regional E (max) was compared with regional perfusion and systolic thickening. In addition, the correlation between E (max) and viability was assessed in dysfunctional segments (thickening or=60%), E (max) was 2.65+/-1.67, while it was 1.30+/-1.24 in the segments of decreased perfusion. With regard to thickening, E (max) was 3.01+/-1.92 mmHg/mL for normal regions (thickening > or=40%), 2.40+/-1.19 mmHg/mL for mildly dysfunctional regions ( or=20%), and 1.13+/-0.89 mmHg/mL for severely dysfunctional regions (< 20%). E (max) was improved after CABG in both the viable (from 1.27+/-1.07 to 1.79+/-1.48 mmHg/mL) and non-viable segments (from 0.97+/-0.59 to 1.22+/-0.71 mmHg/mL), but there was no correlation between E (max) and thickening improvements (r=0.007). CONCLUSIONS: Preoperative regional E (max) was relatively concordant with regional perfusion and systolic thickening on gated myocardial SPECT. In dysfunctional but viable segments, E (max) was improved after CABG, but showed no correlation with thickening improvement. As a load-independent contractility index of dysfunctional myocardial segments, we suggest that the regional E (max) could be an independent parameter in the assessment of myocardial function.