The effects of shade and light irradiation on the polymerization of composite resin core materials / 实用口腔医学杂志

Objective:To evaluate the effects of shade and light irradiation condition on the polymerization of composite resin core material.Methods:The light-proof silicon rubber cuboid mold with one end open were stringed and filled by dual-cured flowable composite resin core material with the shade of dentine and white(Paracore) respectively,then the open end of mold was irradiated directly by a light unit at 1 000 mW/cm2 ×20 s and 3 200 mW/cm2 ×6 s respectively.And all specimens of 4 groups(n =5) were stored in the light-proof box.1 h and 24 h after irradiation,Knoop microhardness was measured along the vertical surfaces of the specimens at the depth of 1,2 and 3 mm respectively.Data were analyzed by One-way ANOVA.Results:At all light irradiation conditions,the hardness of all specimens decreased with the increase of measurement depth.24 h after irradiation,the hardness of dentine shade specimens at each measurement depth showed no difference between 1 000 mW/cm2 × 20 s and 3 200 mW/cm2 × 6 s irradiation,while the white shade specimens irradiated by 1 000 mW/cm2 × 20 s showed higher hardness than those by 3 200 mW/cm2 × 6 s.Conclusion:To obtain sufficient polymerization of composite core material with different shade optimal light irradiation condition should be selected.

Effect of different surface treatments on microtensile bond strength of two resin cements to aged simulated composite core materials.

Objective: Roughening of the aged composite resin core (CRC) surface seems essential for durable adhesion. The aim of this study was to investigate the influence of various surface treatments and different resin cements on microtensile bond strength (μTBS) between two aged core build‑up composites (CBCs) and feldspathic ceramic. Materials and Methods: A total of 16 composite blocks made of two CBCs, Core.it and Build‑it were randomly assigned to four surface treatment groups after water storage and thermocycling (2 weeks and 500 cycles). Experimental groups included surface roughening with air abrasion (AA), hydrofluoric acid, pumice, and laser and then were bonded to computer‑aided design/computer‑aided manufacturing feldspathic ceramic blocks using two resin cements, Panavia F2 (PF), and Duo‑link (DL). The μTBS was tested, and the fracture mode was assessed. The data were analyzed with multiple analysis of variance to estimate the contribution of different surface treatments, resin cements, and two aged CRCs on μTBS. Statistical significance level was set at α < 0.05. Results: Surface treatment and cement type significantly affected bond strength (P < 0.001) but the type of CRC did not (P = 0.468). Between roughening methods, the highest and the lowest values of μTBS were sequentially obtained in AA and Er.YAG laser groups. The highest bond strength was in AA group cemented with PF (31.83 MPa). The most common failure mode was cohesive fracture in the cement. Conclusion: Different surface treatments had different effects on μTBS of aged CRCs to feldspathic ceramics. PF was significantly better than DL.

Influência de diferentes métodos de condicionamento superficial em pinos pré-fabricados resinosos fibro-reforçados em vidro e quartzo na resistência adesiva a compósito de polimerização dual: teste de push-out / Influence of different pretreatments in glass and quartz fiber posts on the bond strength of a dual-cure resin core material: push-out test

O objetivo deste estudo foi realizar uma avaliação tridimensional da rugosidade superficial em 3 tipos de pinos de fibra - DT LightPost®, FRC Postec Plus® e Transluma Post™ - submetidos a diferentes tratamentos de superfície e avaliar os efeitos dos pré-tratamentos na resistência adesiva a um compósito de presa dual Biscore™. Os tratamentos de superfície foram: imersão em ácido hidrofluorídrico, jateamento com óxido de alumínio a 50µm, imersão em peróxido de hidrogênio, jateamento com óxido de alumínio a 50µm seguido de imersão em ácido hidrofluorídrico e jateamento com óxido de alumínio a 50µm seguido de imersão em peróxido de hidrogênio. No experimento 1, 75 pinos foram divididos em 3 grupos (n = 25), de acordo com seu fabricante e subdivididos em cinco subgrupos. A rugosidade superficial foi medida usando um rugosímetro tridimensional e analisada com o software de análise 3D. Os valores de rugosidade foram obtidos antes e após diferentes tratamentos de superfície na área dos mesmos corpos-de-prova. Para o experimento 2, foram utilizados os mesmos corpos-de-prova, os mesmos grupos e subgrupos do experimento 1, tendo sido adicionado o subgrupo de controle (n=90) e a resistência adesiva a um compósito presa dual Biscore™ foi mensurada através de um teste push-out. A resistência adesiva foi medida em uma máquina universal de ensaios, com uma célula de carga tipo SLBL-5kN em uma velocidade de 0,5 mm / min. Os resultados do experimento 1 foram analisados através de um teste estatístico t-Student. Jateamento e jateamento seguido de imersão em ácido hidrofluorídrico produziram um aumento estatisticamente significante na rugosidade, contudo somente o tratamento por jateamento proporcionou um aumento significativo nos valores de rugosidade. Os resultados do experimento 2 foram obtidos através de um um teste t-unilateral de hipótese com variância desconhecida. Concluiu-se que o jateamento com óxido de alumínio a 50μm em uma distância de 30 mm a 2,5 bar ...

The aim of this study was to perform a tridimensional surface roughness test evaluation of different surface treatments to 3 types of fiber posts - DT LightPost®, FRC Postec Plus® e Transluma Post™ - and evaluate the effects of the different pretreatments on the bond strength of a dual-cure resin core material Biscore™. The different surface treatments were: immersion in hydrofluoric acid, sandblasting abrasion with 50 µ alumina particles, immersion in hydrogen peroxide, sandblasting abrasion with 50 µ alumina particles followed by immersion in hydrofluoric acid and sandblasting abrasion with 50 µ alumina particles followed by immersion in hydrogen peroxide. In the first experiment seventy five fiber posts were divided into 3 groups (n = 25), according to their manufacturer and subdivided into 5 subgroups. Surface roughness was measured using a tridimensional surface roughness test and analyzed with 3D analysis software. Surface roughness was obtained before and after the different surface treatments at the same post area. In the second experiment the same samples divided in groups and subgroups were used, but a control group (no treatment) was added (n = 90) and the bond strength to a composite resin core material Biscore™ was measured using a push-out design. The interfacial push-out bond strength was measured in a universal testing machine, with a load cell type SLBL-5kN at a crosshead speed of 0.5 mm/min. Results in experiment 1 were statistically analyzed using Student´s t-Test. Sandblasting and sandblasting followed by immersion in hydrofluoric acid produced a significant increase in roughness, but the sandblasting treatment was able to provide a significant roughness increase. Results in experiment 2 were statistically analysed using one-sided t-Test of Hypothesis with unknown variance. It was concluded that sandblasting airborne-particle abrasion with alumina 50µ at a distance of 30 mm at 2.5 bars pressure for 5 seconds was ...

Influência de diferentes métodos de condicionamento superficial em pinos pré-fabricados resinosos fibro-reforçados em vidro e quartzo na resistência adesiva a compósito de polimerização dual: teste de push-out / Influence of different pretreatments in glass and quartz fiber posts on the bond strength of a dual-cure resin core material: push-out test

O objetivo deste estudo foi realizar uma avaliação tridimensional da rugosidade superficial em 3 tipos de pinos de fibra - DT LightPost®, FRC Postec Plus® e Transluma Post™ - submetidos a diferentes tratamentos de superfície e avaliar os efeitos dos pré-tratamentos na resistência adesiva a um compósito de presa dual Biscore™. Os tratamentos de superfície foram: imersão em ácido hidrofluorídrico, jateamento com óxido de alumínio a 50µm, imersão em peróxido de hidrogênio, jateamento com óxido de alumínio a 50µm seguido de imersão em ácido hidrofluorídrico e jateamento com óxido de alumínio a 50µm seguido de imersão em peróxido de hidrogênio. No experimento 1, 75 pinos foram divididos em 3 grupos (n = 25), de acordo com seu fabricante e subdivididos em cinco subgrupos. A rugosidade superficial foi medida usando um rugosímetro tridimensional e analisada com o software de análise 3D. Os valores de rugosidade foram obtidos antes e após diferentes tratamentos de superfície na área dos mesmos corpos-de-prova. Para o experimento 2, foram utilizados os mesmos corpos-de-prova, os mesmos grupos e subgrupos do experimento 1, tendo sido adicionado o subgrupo de controle (n=90) e a resistência adesiva a um compósito presa dual Biscore™ foi mensurada através de um teste push-out. A resistência adesiva foi medida em uma máquina universal de ensaios, com uma célula de carga tipo SLBL-5kN em uma velocidade de 0,5 mm / min. Os resultados do experimento 1 foram analisados através de um teste estatístico t-Student. Jateamento e jateamento seguido de imersão em ácido hidrofluorídrico produziram um aumento estatisticamente significante na rugosidade, contudo somente o tratamento por jateamento proporcionou um aumento significativo nos valores de rugosidade. Os resultados do experimento 2 foram obtidos através de um um teste t-unilateral de hipótese com variância desconhecida. Concluiu-se que o jateamento com óxido de alumínio a 50μm em uma distância de 30 mm a 2,5 bar ...

The aim of this study was to perform a tridimensional surface roughness test evaluation of different surface treatments to 3 types of fiber posts - DT LightPost®, FRC Postec Plus® e Transluma Post™ - and evaluate the effects of the different pretreatments on the bond strength of a dual-cure resin core material Biscore™. The different surface treatments were: immersion in hydrofluoric acid, sandblasting abrasion with 50 µ alumina particles, immersion in hydrogen peroxide, sandblasting abrasion with 50 µ alumina particles followed by immersion in hydrofluoric acid and sandblasting abrasion with 50 µ alumina particles followed by immersion in hydrogen peroxide. In the first experiment seventy five fiber posts were divided into 3 groups (n = 25), according to their manufacturer and subdivided into 5 subgroups. Surface roughness was measured using a tridimensional surface roughness test and analyzed with 3D analysis software. Surface roughness was obtained before and after the different surface treatments at the same post area. In the second experiment the same samples divided in groups and subgroups were used, but a control group (no treatment) was added (n = 90) and the bond strength to a composite resin core material Biscore™ was measured using a push-out design. The interfacial push-out bond strength was measured in a universal testing machine, with a load cell type SLBL-5kN at a crosshead speed of 0.5 mm/min. Results in experiment 1 were statistically analyzed using Student´s t-Test. Sandblasting and sandblasting followed by immersion in hydrofluoric acid produced a significant increase in roughness, but the sandblasting treatment was able to provide a significant roughness increase. Results in experiment 2 were statistically analysed using one-sided t-Test of Hypothesis with unknown variance. It was concluded that sandblasting airborne-particle abrasion with alumina 50µ at a distance of 30 mm at 2.5 bars pressure for 5 seconds was ...

Influence of modification in core building procedure on fracture strength and failure patterns of premolars restored with fiber post and composite core

PURPOSE: The influence of the modified process in the fiber-reinforced post and resin core foundation treatment on the fracture resistance and failure pattern of premolar was tested in this study. MATERIALS AND METHODS: Thirty-six human mandibular premolars were divided into 4 groups (n = 9). In group DCT, the quartz fibre post (D.T. Light-post) was cemented with resin cement (DUO-LINK) and a core foundation was formed with composite resin (LIGHT-CORE). In group DMO and DMT, resin cement (DUO-LINK) was used for post (D.T. Light-post) cementation and core foundation; in group DMO, these procedures were performed simultaneously in one step, while DMT group was accomplished in separated two steps. In group LCT, the glass fiber post (LuxaPost) cementation and core foundation was accomplished with composite resin (LuxaCore-Dual) in separated procedures. Tooth were prepared with 2 mm ferrule and restored with nickel-chromium crowns. A static loading test was carried out and loads were applied to the buccal surface of the buccal cusp at a 45 degree inclination to the long axis of the tooth until failure occurred. The data were analyzed with MANOVA (alpha = .05). The failure pattern was observed and classified as either favorable (allowing repair) or unfavorable (not allowing repair). RESULTS: The mean fracture strength was highest in group DCT followed in descending order by groups DMO, DMT, and LCT. However, there were no significant differences in fracture strength between the groups. A higher prevalence of favorable fractures was detected in group DMT but there were no significant differences between the groups. CONCLUSION: The change of post or core foundation method does not appear to influence the fracture strength and failure patterns.

Influence of modification in core building procedure on fracture strength and failure patterns of premolars restored with fiber post and composite core

PURPOSE: The influence of the modified process in the fiber-reinforced post and resin core foundation treatment on the fracture resistance and failure pattern of premolar was tested in this study. MATERIALS AND METHODS: Thirty-six human mandibular premolars were divided into 4 groups (n = 9). In group DCT, the quartz fibre post (D.T. Light-post) was cemented with resin cement (DUO-LINK) and a core foundation was formed with composite resin (LIGHT-CORE). In group DMO and DMT, resin cement (DUO-LINK) was used for post (D.T. Light-post) cementation and core foundation; in group DMO, these procedures were performed simultaneously in one step, while DMT group was accomplished in separated two steps. In group LCT, the glass fiber post (LuxaPost) cementation and core foundation was accomplished with composite resin (LuxaCore-Dual) in separated procedures. Tooth were prepared with 2 mm ferrule and restored with nickel-chromium crowns. A static loading test was carried out and loads were applied to the buccal surface of the buccal cusp at a 45 degree inclination to the long axis of the tooth until failure occurred. The data were analyzed with MANOVA (alpha = .05). The failure pattern was observed and classified as either favorable (allowing repair) or unfavorable (not allowing repair). RESULTS: The mean fracture strength was highest in group DCT followed in descending order by groups DMO, DMT, and LCT. However, there were no significant differences in fracture strength between the groups. A higher prevalence of favorable fractures was detected in group DMT but there were no significant differences between the groups. CONCLUSION: The change of post or core foundation method does not appear to influence the fracture strength and failure patterns.

Effect of ascorbic acid, ethanol and acetone on adhesion between the treated fiber posts and composite resin cores

PURPOSE: The aim of the present study was to assess the effect of ascorbic acid, ethanol and acetone on microtensile bond strength between fiber posts pre-treated with hydrogen peroxide and composite resin cores. MATERIALS AND METHODS: Twenty four fiber posts were pre-treated with 24% hydrogen peroxide and divided into 4 groups as follows: G1: no treatment, as control group; G2: treatment with 10% ascorbic acid solution for 5 minutes; G3: treatment with 70% ethanol solution for 5 minutes; and G4: treatment with 70% acetone solution for 5 minutes. Each fiber post was surrounded by a cylinder-shaped polyglass matrix which was subsequently filled with composite resin. Two sections from each sample were selected for microtensile test at a crosshead with speed of 0.5 mm/min. Statistical analyses were performed using one-way ANOVA and a post hoc Tukey HSD test. Fractured surfaces were observed under a stereomicroscope at x20 magnification. The fractured surfaces of the specimens were observed and evaluated under a SEM. RESULTS: Means of microtensile bond strength values (MPa) and standard deviations in the groups were as follows: G1: 9.70+/-0.81; G2: 12.62+/-1.80; G3: 16.60+/-1.93; and G4: 21.24+/-1.95. G4 and G1 had the highest and the lowest bond strength values, respectively. A greater bond strength value was seen in G3 compared to G2. There were significant differences between all the groups (P<.001). All the failures were of the adhesive mode. CONCLUSION: Application of antioxidant agents may increase microtensile bond strength between fiber posts treated with hydrogen peroxide and composite cores. Acetone increased bond strength more than ascorbic acid and ethanol.

Effect of surface treatments of fiber posts on bond strength to composite resin cores / 대한치과보존학회지

The purpose of the present study was to compare the influence of post-surface treatment with silane, hydrogen peroxide, hydrofluoric acid or sandblasting and to investigate the effect of silane in combination of the other treatments on the microtensile bond strength between fiber posts and composite resins for core build-up. Thirty-two glass-fiber posts (FRC Postec Plus, Ivoclar Vivadent, Schaan, Liechtenstein) were divided into eight groups according to the different surface pretreatments performed: silane application (S); immersion in 28% hydrogen peroxide (HP); immersion in hydrogen peroxide followed by application of silane (HP-S); immersion in 4% hydrofluoric acid gel (HF); immersion in hydrofluoric acid gel followed by application of silane (HF-S); sandblasting with aluminum oxide particles (SB); sandblasting followed by application of silane (SB-S). In control group, no surface treatment was performed. The composite resin (Tetric Flow, Ivoclar Vivadent, Schaan, Liechtenstein) was applied onto the posts to produce the composite cylinder specimen. It was sectioned into sticks to measure the microtensile bond strength. The data was analyzed with one-way ANOVA and LSD test for post hoc comparison (p < 0.05). Post pretreatment with sandblasting enhanced the interfacial strength between the fiber posts and core materials. Moreover, sand-blasting followed by application of silane appears to be the most effective method that can improve the clinical performance of glass fiber posts.

The influence of AH-26 and zinc oxide-eugenol root canal sealer on the shear bond strength of composite resin to dentin / 대한치과보존학회지

The purpose of this study was to evaluate the influence of the AH-26 root canal sealer on the shear bond strength of composite resin to dentin. One hundred and forty four (144) extracted, sound human molars were used. After embedding in a cylindrical mold, the occlusal part of the anatomical crown was cut away and trimmed in order to create a flat dentin surface. The teeth were randomly divided into three groups; the AH-26 sealer was applied to the AH-26 group, and zinc-oxide eugenol (ZOE) paste was applied to the ZOE group. The dentin surface of the control group did not receive any sealer. A mount jig was placed against the surface of the teeth and the One-step dentin bonding agent was applied after acid etching. Charisma composite resin was packed into the mold and light cured. After polymerization, the alignment tube and mold were removed and the specimens were placed in distilled water at 37degrees C for twenty four hours. The shear bond strength was measured by an Instron testing machine. The data for each group were subjected to one-way ANOVA and Tukey's studentized rank test so as to make comparisons between the groups. The AH-26 group and the control group showed significantly higher shear bond strength than the ZOE group (p 0.05). Under the conditions of this study, the AH-26 root canal sealer did not seem to affect the shear bond strength of the composite resin to dentin while the ZOE sealer did. Therefore, there may be no decrease in bond strength when the composite resin core is built up immediately after a canal filling with AH-26 as a root canal sealer.

A STUDY OF CORE TYPE AND LUTING CEMENTS ON COMPLETE CAST CROWN RETENTION / 대한치과보철학회지

The purpose of this study was to compare the retention of complete cast crown over amalgam cores, composite resin cores, and cast gold cores when cemented with three different luting agents. Eighteen core specimens each of amalgam(Bestaloy, Dong Myung, Seoul, Korea), composite resin (Z100, 3M Dental product, st. Paul, Minn) and type N gold alloy (Ba 4, Heesung Engelhard Corp., Korea) were made in a customized milling stainless steel die. A wax pattern with a loop attached to occlusal surface was made for each core and a type 11 gold alloy casting was fabricated. The castings which had clinically acceptable marginal fit were used as test samples. The following luting cements were used to cement cast crowns on each core material : (1) zinc phosphate cement (Confi dental Products Co., USA) (2) glass-ionomer cement (Fuji Plus, GC Industrial Corp., Tokyo, Japan) (3) resin cement (Panavia 21, Kuraray Co., USA). All cements were mixed according to manufacturers instructions. A static load of 5kg was then applied for 10 minutes on the crowns. All specimens were stored in saline solution for 24 hours at 371C and thermocycled for 500 cycles. After storage and cycling, the tensile bond strengths were measured by using a universal testing machine (Instron Corp., Canton, Mass.) at a crosshead speed of 0.5mm/min. The results were as follows : 1. The retentive strength of resin cement was the highest of all three types of cement for resin core (p0.05). 3. The retentive strength of resin cement was higher than that of zinc phosphate for cast core, but there was no difference between the retentive strength of glass ionomer cement and those of rein and zinc phosphate cement. 4. The retentive strength of the zinc phosphate cement for amalgam core was the highest of all type of cores.