ABSTRACT
A resistência à tração diametral (TD) é um requisito essencial para o sucesso clínico das restaurações. Dessa forma, este estudo objetivou avaliar a resistência à TD de três tipos cimentos ionômero de vidro (CIV) em comparação com uma resina composta, todos utilizados em seis postos de saúde pública do município de Duque de Caxias/RJ. O TD foi realizado em uma máquina universal com uma célula de carga de 200 Kgf. Os valores médios de resistência à TD, em MPa, foram: 11,46 (CIV A), 10 (CIV B), 31 (CIV C) e 38,13 (Resina). Os resultados foram analisados pelos testes Anova e Turkey (p < 0,05). Concluiu-se que os CIVs apresentaram resistência à TD semelhante entre eles, porém inferior à resina, mas ainda sendo uma ótima opção para restauração preconizada pelo Serviço Público de Saúde (SUS).
The diametric tensile strength (DT) is a prerequisite for clinical success of restoration. Thus, this study aimed to evaluate the resistance of DT of three types of glass ionomer cements (IO) for restorative, and compare with a composite resin. Eight samples of each material were using by bipartite matrices. All of the materials were used according to manufacturers. The DT test was performed using a universal testing machine with a load of 200 kgf. The results were analyzed using Anova and Turkey (p <0.05). Mean values for resistance to DT in MPa were: 11.46 (IO A), 10 (IO B), 31 (IO C) and 38.13 (Resin composite). We concluded that IO showed similar DT among themselves.
Subject(s)
Tensile Strength , In Vitro Techniques , Composite Resins , Dental Materials , Glass Ionomer CementsABSTRACT
A resistência à tração diametral (TD) é um requisito essencial para o sucesso clínico das restaurações. Dessa forma, este estudo objetivou avaliar a resistência à TD de três tipos cimentos ionômero de vidro (CIV) em comparação com uma resina composta, todos utilizados em seis postos de saúde pública do município de Duque de Caxias/RJ. O TD foi realizado em uma máquina universal com uma célula de carga de 200 Kgf. Os valores médios de resistência à TD, em MPa, foram: 11,46 (CIV A), 10 (CIV B), 31 (CIV C) e 38,13 (Resina). Os resultados foram analisados pelos testes Anova e Turkey (p < 0,05). Concluiu-se que os CIVs apresentaram resistência à TD semelhante entre eles, porém inferior à resina, mas ainda sendo uma ótima opção para restauração preconizada pelo Serviço Público de Saúde (SUS).
The diametric tensile strength (DT) is a prerequisite for clinical success of restoration. Thus, this study aimed to evaluate the resistance of DT of three types of glass ionomer cements (IO) for restorative, and compare with a composite resin. Eight samples of each material were using by bipartite matrices. All of the materials were used according to manufacturers. The DT test was performed using a universal testing machine with a load of 200 kgf. The results were analyzed using Anova and Turkey (p <0.05). Mean values for resistance to DT in MPa were: 11.46 (IO A), 10 (IO B), 31 (IO C) and 38.13 (Resin composite). We concluded that IO showed similar DT among themselves.
Subject(s)
Tensile Strength , Composite Resins , Dental Materials , Glass Ionomer CementsABSTRACT
Aim: The aim of this study is to evaluate the influence of different combinations of irradiance and exposure time for a given radiant exposure on the degree of conversion (DC) and on the mechanical properties of two resin composites: Filtek Z250 and Filtek P90 LS (3M ESPE). Materials and Methods: The following curing protocols were used: Standard irradiance: 400 mW/cm² for 60 s; Medium irradiance: 700 mW/cm² for 34 s and High irradiance: 950 mW/cm² for 26 s. The DC was measured using Fourier Transform Infrared spectroscopy. Each specimen was submitted to five indentations to evaluate the Knoop microhardness (KHN). The flexural strength (FS) was obtained from the three‑point bending test. Cylindrical specimens were prepared for the Diametral tensile strength (DTS) test. Statistical analysis: Data were evaluated using two‑way ANOVA and Tukey’s test (a = 0.05). Results: DC and DTS were not influenced by the different curing protocols. For P90, the medium irradiance showed higher values of KHN than the standard irradiance. For Z250, the high irradiance showed higher values of FS than the standard irradiance. Conclusion: The influence of the different combinations of irradiance and exposure time depends on the resin composite as well as the specifically evaluated mechanical property.
ABSTRACT
Introdução: O cimento de ionômero de vidro é um material odontológico que apresenta limitações de uso devido às suas propriedades mecânicas, como baixa resistência ao desgaste, microdureza, compressão e tração diametral. Com base nisso, este estudo investigou o efeito da excitação ultrassônica sobre o CIV, em diferentes tempos de aplicação, por meio da resistência à tração diametral. Material e Método: Os materiais utilizados foram o Ketac Molar Easymix (KME) e o Ketac Cem Easymix (KCE). Foram confeccionados 10 corpos de prova para cada condição estudada: grupo controle, e os grupos que receberam aplicação de ultrassom por 15s, 30s e 45s, para ambos materiais. A excitação ultrassônica foi aplicada durante a reação de presa inicial do CIV, logo após sua inserção na matriz de silicone. Os valores de resistência à tração diametral foram analisados pelo teste Shapiro Wilk e Anova (α = 0.05). Resultado: A aplicação de excitação ultrassônica não apresentou efeito estatisticamente significante na resistência à tração diametral dos materiais testados, independente do tempo de aplicação (p > 0,05). O KME apresentou resistência estatisticamente maior que o KCE (p = 0,023). Conclusão: A utilização das ondas ultrassônicas não influenciou na resistência à tração diametral dos CIV testados independentemente do seu tempo de aplicação.
Introduction: The glass ionomer cement is a dental material that has limitations of use due to its mechanical properties, such as low wear resistance, hardness, tensile and compressive diametral. Based on this, this study investigated the effect of ultrasonic excitation on the GIC in different application times, through the diametral tensile strength. Material and Method: The materials used were Ketac Molar EasyMix (KME) and Ketac Cem EasyMix (KCE). Were made 10 specimens for each condition studied: control group, and the groups that received application of ultrasound for 15s, 30s and 45s, for both materials. The ultrasonic excitation was applied during the initial setting reaction of GIC, soon after its insertion into the silicone matrix. The values of the diametral tensile strength were analyzed by Shapiro Wilk test and ANOVA (α = 0.05). Result: The application of ultrasonic excitation showed no statistically significant effect on diametral tensile strength of the materials tested, regardless of the time of application (p > 0.05). The KME resistance showed statistically greater than the KCE (p = 0.023). Conclusion: The use of ultrasound waves did not influence the diametral tensile strength of CIV tested regardless of their time of application.
Subject(s)
Tensile Strength , Ultrasonics , Analysis of Variance , Glass Ionomer CementsABSTRACT
PURPOSE: The purpose of this study was to investigate the diametral tensile strength of polymer-based temporary crown and fixed partial denture (FPD) materials, and the change of the diametral tensile strength with time. MATERIAL AND METHODS: One monomethacrylate-based temporary crown and FPD material (Trim) and three dimethacrylate-based ones (Protemp 3 Garant, Temphase, Luxtemp) were investigated. 20 specimens (the empty set 4 mm x 6 mm) were fabricated and randomly divided into two groups (Group I: Immediately, Group II: 1 hour) according to the measurement time after completion of mixing. Universal Testing Machine was used to load the specimens at a cross-head speed of 0.5 mm/min. The data were analyzed using one-way ANOVA, the multiple comparison Scheffe test and independent sample t test (alpha = 0.05). RESULTS: Trim showed severe permanent deformation without an obvious fracture during loading at both times. There were statistically significant differences among the dimethacrylate-based materials. The dimethacrylate-based materials presented an increase in strength from 5 minutes to 1 hour and were as follows: Protemp 3 Garant (23.16 - 37.6 MPa), Temphase (22.27 - 28.08 MPa), Luxatemp (14.46 - 20.59 MPa). Protemp 3 Garant showed the highest value. CONCLUSION: The dimethacrylate-based temporary materials tested were stronger in diametral tensile strength than the monomethacrylate-based one. The diametral tensile strength of the materials investigated increased with time.
Subject(s)
Acrylic Resins , Bisphenol A-Glycidyl Methacrylate , Collodion , Composite Resins , Crowns , Denture, Partial, Fixed , Methacrylates , Polymethacrylic Acids , Tensile StrengthABSTRACT
The purpose of this study was to determine the influence of incrementally added uncured HEMA in experimental HEMA-added glass ionomer cement (HAGICs) on the mechanical and shear bond strength (SBS) of these materials. Increasing contents of uncured HEMA (10-50 wt. percent) were added to a commercial glass ionomer cement liquid (Fuji II, GC, Japan), and the compressive and diametral tensile strengths of the resulting HAGICs were measured. The SBS to non-precious alloy, precious alloy, enamel and dentin was also determined after these surfaces were subjected to either airborne-particle abrasion (Aa) or SiC abrasive paper grinding (Sp). Both strength properties of the HAGICs first increased and then decreased as the HEMA content increased, with a maximum value obtained when the HEMA content was 20 percent for the compressive strength and 40 percent for the tensile strength. The SBS was influenced by the HEMA content, the surface treatment, and the type of bonding surface (p<0.05). These results suggest that addition of an appropriate amount of HEMA to glass ionomer cement would increase diametral tensile strength as well as bond strength to alloys and teeth. These results also confirm that the optimal HEMA content ranged from 20 to 40 percent within the limitations of this experimental condition.
Subject(s)
Eyeglasses , Methacrylates/metabolism , Biomechanical Phenomena , Microscopy, Atomic Force , Microscopy, Electron, Scanning , Tensile StrengthABSTRACT
BACKGROUND: There are many species of ceramic bonding systems supplied in market, the mechanical strength is aprerequisite condition for resin cement in clinical use.OBJECTIVE: To study the difference of mechanical strength between Panavia F resin cement and self-made resin cement,DESIGN, TIME AND SETTING: A controlled observational study was performed in the prosthesis laboratory of the FourthMilitary Medical University of Chinese PLA between May 2006 and March 2007.MATERIALS: Panavia F resin cement was sourced from KURARAY MEDICAL INC. (Japan), experimental resin cement wasproduced by College of Stomatological Medicine in the Fourth Military Medical University of Chinese PLA.METHODS: Five cylindrical compressive strength specimens at an 8-mm height and 4-mm diameter were prepared, as well as5 cylindrical diametral tensile strength specimens at a 3-mm height and 6-mm diameter. AGS-500 universal material testingmachine was applied to detect the compressive strength and diametral tensile strength.MAIN OUTCOME MEASURES: The diametral tensile strength test and compressive strength test of the specimens.RESULTS: The compressive strength of Panavia F resin cement was remarkably higher than that of experimental cement[(238.92±24.54), (149.08±12.13) M Pa, P ＜ 0.05]. There were no significances between two resin cements on diametral tensilestrength (P＞ 0.05).CONCLUSION: There were no significance between two resin cements on diametral tensile strength following completecuring. The compressive strength of experimental resin cement can reach the standard of ADA (＞ 70 MPa) although it is lowerthan the compressive strength of Panavia F resin cement.