scholarly journals Wear Resistance of Bulk-fill Composite Resin Restorative Materials Polymerized under different Curing Intensities

2017 ◽  
Vol 18 (1) ◽  
pp. 39-43
Author(s):  
Fahad Alkhudhairy
Keyword(s):  
Wear Resistance ◽  
Light Intensity ◽  
High Intensity ◽  
Composite Resin ◽  
Surface Loss ◽  
Low Intensity ◽  
Significant Difference ◽  
Restorative Materials ◽  
Light Curing ◽  
Curing Light

ABSTRACT Introduction The aim of this study was to assess the wear resistance of four bulk-fill composite resin restorative materials cured using high- and low-intensity lights. Materials and methods Twenty-four samples were prepared from each composite resin material (Tetric N-Ceram, SonicFill, Smart Dentin Replacement, Filtek Bulk-Fill) resulting in a total of 96 samples; they were placed into a mold in a single increment. All of the 96 samples were cured using the Bluephase N light curing unit for 20 seconds. Half of the total specimens (n = 48) were light cured using high-intensity output (1,200 mW/cm2), while the remaining half (n = 48) were light cured using low-intensity output (650 mW/cm2). Wear was analyzed by a three-dimensional (3D) noncontact optical profilometer (Contour GT-I, Bruker, Germany). Mean and standard deviation (SD) of surface loss (depth) after 120,000 cycles for each test material was calculated and analyzed using one-way analysis of variance (ANOVA) with a significance level at p < 0.05. Results The least mean surface loss was observed for SonicFill (186.52 µm) cured using low-intensity light. No significant difference in the mean surface loss was observed when comparing the four tested materials with each other without taking the curing light intensity into consideration (p = 0.352). A significant difference in the mean surface loss was observed between SonicFill cured using high-intensity light compared with that cured using low-intensity light (p < 0.001). Conclusion A higher curing light intensity (1,200 mW/cm2) had no positive influence on the wear resistance of the four bulk-fill composite resin restorative materials tested compared with lower curing light intensity (650 mW/cm2). Furthermore, SonicFill cured using low-intensity light was the most wearresistant material tested, whereas Tetric N-Ceram cured using high-intensity light was the least wear resistant. Clinical significance The wear resistance was better with the newly introduced bulk-fill composite resins under low-intensity light curing. How to cite this article Alkhudhairy F. Wear Resistance of Bulk-fill Composite Resin Restorative Materials Polymerized under different Curing Intensities. J Contemp Dent Pract 2017;18(1):39-43.

scholarly journals Influence of Volumetric Shrinkage and Curing Light Intensity on Proximal Contact Tightness of Class II Resin Composite Restorations: In Vitro Study

2012 ◽  
Vol 37 (2) ◽  
pp. 205-210 ◽  
Author(s):  
H El-Shamy ◽  
MH Saber ◽  
CE Dörfer ◽  
W El-Badrawy ◽  
BAC Loomans
Keyword(s):  
Light Intensity ◽  
High Intensity ◽  
Resin Composite ◽  
In Vitro Study ◽  
Class Ii ◽  
Volumetric Shrinkage ◽  
Low Intensity ◽  
Composite Restorations ◽  
Curing Light

SUMMARY Background Proximal contact tightness of class II resin composite restorations is influenced by a myriad of factors. Previous studies investigated the role of matrix band type and thickness, consistency of resin composite, and technique of placement. However, the effect of volumetric shrinkage of resin and intensity of curing light has yet to be determined. Thus, the aim of this study was to identify the influence of these factors on the proximal contact tightness when restoring class II cavity preparations in vitro. Methods Sixty artificial molars were restored with either a low-shrinkage (Filtek Silorane, 3M ESPE) or a conventional (Z100, 3M ESPE) composite and polymerized with low-intensity (Smartlite IQ2, Dentsply) or high-intensity light curing units (DemiTM, Kerr). Proximal contact tightness was measured using the Tooth Pressure Meter. Data were statistically analyzed using one-way analysis of variance and Tukey post hoc test. Results Use of low-shrinkage composite (Filtek Silorane) resulted in significantly tighter proximal contacts compared to the use of conventional composite (Z100) when cured with the same polymerization unit (p&lt;0.001). Moreover, the low-intensity curing unit (IQ2) resulted in significantly tighter contacts than the high-intensity unit when material is constant (p&lt;0.001). Conclusions Low-shrinkage resin composite and low curing light intensity is associated with tighter proximal contact values.

scholarly journals Compressive strength of esthetic restorative materials polymerized with quartz-tungsten-halogen light and blue LED

2009 ◽  
Vol 20 (1) ◽  
pp. 54-57 ◽  
Author(s):  
Cecy Martins Silva ◽  
Katia Regina Hostilio Cervantes Dias
Keyword(s):  
Compressive Strength ◽  
Light Source ◽  
Composite Resin ◽  
Light Emitting Diode ◽  
Testing Machine ◽  
Quartz Tungsten Halogen ◽  
Halogen Light ◽  
Significant Difference ◽  
Restorative Materials ◽  
Light Curing

This study compared the compressive strength of a composite resin and compomer photoactivated with a conventional quartz-tungsten halogen-light (XL 3000, 3M/SPE) and a blue light-emitting diode (LED) (SmartLite PS; Dentsply/De Trey). Forty disc-shaped specimens were prepared using a split polytetrafluoroethylene matrix (4.0 mm diameter x 8.0 mm hight) in which the materials were inserted incrementally. The curing time of each increment was of 40 s with the QTH and 10 s with the LED. The specimens were randomly assigned to 4 groups (n=10), according to the light source and the restorative material. After storage in distilled water at 37oC ± 2oC for 24 h, the specimens was tested in compressive strength in a universal testing machine with load cell of 500 kgf running at a crosshead speed of 0.5 mm/min. Data (in MPa) were analyzed statistically by ANOVA and Student-Newman-Keuls test (p<0.05). For the composite resin, light curing with the QTH source did not produce statistically significant difference (p>0.05) in the compressive strength when compared to light curing with the LED source. However, light curing of the compomer with the QTH source resulted in significantly higher compressive strength than the use of the LED unit (p>0.05). The composite resin presented significantly higher (p>0.05) compressive strength than the compomer, regardless of the light source. In conclusion, the compressive strength of the tested materials photoactivated with a QTH and a LED light source was influenced by the energy density employed and the chemical composition of the esthetic restorative materials.

scholarly journals Microleakage under Orthodontic Brackets Using High-Intensity Curing Lights

2009 ◽  
Vol 79 (1) ◽  
pp. 144-149 ◽  
Author(s):  
Mustafa Ulker ◽  
Tancan Uysal ◽  
Sabri Ilhan Ramoglu ◽  
Huseyin Ertas
Keyword(s):  
High Intensity ◽  
Light Emitting Diode ◽  
Bonferroni Correction ◽  
Light Emitting ◽  
Halogen Light ◽  
Halogen Light Source ◽  
Light Curing ◽  
Curing Light ◽  
High Intensity Light ◽  
Nail Varnish

Abstract Objective: To compare the microleakage of the enamel-adhesive-bracket complex at the occlusal and gingival margins of brackets bonded with high-intensity light curing lights and conventional halogen lights. Materials and Methods: Forty-five freshly extracted human maxillary premolar teeth were randomly separated into three groups of 15 teeth each. Stainless steel brackets were bonded in all groups according to the manufacturer's recommendations. Specimens (15 per group) were cured for 40 seconds with a conventional halogen light, 20 seconds with light-emitting diode (LED), and 6 seconds with plasma arc curing light (PAC). After curing, the specimens were further sealed with nail varnish, stained with 0.5% basic-fuchsine for 24 hours, sectioned and examined under a stereomicroscope, and scored for microleakage for the enamel-adhesive and bracket-adhesive interfaces from both the occlusal and gingival margins. Statistical analyses were performed using Kruskal-Wallis and Mann-Whitney U-tests with a Bonferroni correction. Results: The type of light curing unit did not significantly affect the amount of microleakage at the gingival or occlusal margins of investigated interfaces (P &gt;.05). The gingival sides in the LED and PAC groups exhibited higher microleakage scores compared with those observed on occlusal sides for the enamel-adhesive and adhesive-bracket interfaces. The halogen light source showed similar microleakage at the gingival and occlusal sides between both adhesive interfaces. Conclusions: High-intensity curing units did not cause more microleakage than conventional halogen lights. This supports the use of all these curing units in routine orthodontic practice.

scholarly journals Psychological distress and its associated risk factors among university students

2020 ◽  
Vol 66 (4) ◽  
pp. 414-418
Author(s):  
Tingting Li ◽  
Xu Zhang ◽  
Mingming Chen ◽  
Rui Wang ◽  
Lianping He ◽  
...  
Keyword(s):  
Risk Factors ◽  
Psychological Distress ◽  
University Students ◽  
High Intensity ◽  
Education Level ◽  
High Intensity Exercise ◽  
Low Intensity ◽  
Significant Difference ◽  
Associated Risk Factors ◽  
Low Intensity Exercise

SUMMARY OBJECTIVE Psychological distress is an important mental health problem among university students. The goal of this study was to determine psychological distress and its associated risk factors among students in the Anhui province. METHODS A cross-sectional study was conducted in a sample of 1304 students. In this study, a self-administered questionnaire consisting of the general demography and General Health Questionnaire (GHQ-12) was completed. Psychological distress was assessed using the GHQ-12-item questionnaire. A dichotomous category split was imposed on the GHQ-12 for the purpose of analysis. A GHQ-12 score of 4 or higher indicated psychological distress. The data were analyzed by SPSS 20.0 system. RESULTS A total of 1304 samples were analyzed in this study. The results indicated that the education level of the father and mother was associated with the students’ psychological distress (P<0.001). A significant association was found between high-intensity exercise and low-intensity exercise and psychological distress. However, no significant difference was identified between gender and psychological distress (P=0.173). CONCLUSION The education level of parents, high-intensity exercise, and low-intensity exercise were associated with psychological distress. Our results suggest that it is indispensable to raise awareness of psychological disorders and its associated risk factors among university students. Further studies are required to develop appropriate interventions for high-risk groups.

scholarly journals Impact of Intracoronal Dentin Treatment Prior to Bleaching on Bond Strength of Restorative Materials

2014 ◽  
Vol 25 (6) ◽  
pp. 519-523 ◽  
Author(s):  
Erica Moreno Zanconato-Carvalho ◽  
João Felipe Bruniera ◽  
Natália Spadini de Faria ◽  
Vivian Colucci ◽  
Danielle Cristine Messias
Keyword(s):  
Phosphoric Acid ◽  
Bond Strength ◽  
Surface Treatment ◽  
Shear Bond Strength ◽  
Composite Resin ◽  
Er:Yag Laser ◽  
Composite Resins ◽  
Bleaching Procedure ◽  
Significant Difference ◽  
Restorative Materials

Surface treatment of dentin before the bleaching procedure may affect its permeability and influence the bond strength of restorative materials. This study evaluated the influence of surface treatment before the bleaching on shear bond strength (SBT) of restorative materials to intracoronal dentin. Dentin slabs were subjected to surface treatment: no bleaching (control - CON), no surface treatment + bleaching (HP), 37% phosphoric acid + bleaching (PA) and Er:YAG laser + bleaching (L). After the bleaching procedure, specimens (n=10) were restored with: microhybrid composite resin (MH), flowable composite resin (F), and resin-modified glass-ionomer cement (RMGIC). The shear test was carried out. ANOVA and Tukey's test (α=0.05) showed significant difference for surface treatment and restorative materials (p<0.05). CON presented higher STB and was statistically different from HP (p<0.05). PA and L showed intermediate values and were statistically similar to CON and HP (p>0.05). STB for MH and F were higher than RMGIC (p<0.05), and did not differ from each other (p>0.05). The surface treatments with phosphoric acid and Er:YAG laser before the bleaching procedure provided shear bond strength at the same level of unbleached dentin and the composite resins presented superior bond strength to the intracoronal dentin.

scholarly journals The Influence of Different Light Curing Modes on the Depth of Cure of the Composite Resin

2018 ◽  
Vol 35 (1) ◽  
pp. 58-64
Author(s):  
Nikola Miljković ◽  
Stefan Dačić ◽  
Tamara Karuntanović ◽  
Marko Igić ◽  
Milica Dačić ◽  
...  
Keyword(s):  
Composite Resin ◽  
Composite Layer ◽  
Composite Specimen ◽  
Depth Of Cure ◽  
Average Value ◽  
Clinical Recommendation ◽  
Significant Difference ◽  
Light Curing ◽  
Metal Block ◽  
Digital Caliper

Summary The aim of this study was to investigate the influence of different light curing modes on the depth of cure of the composite resin. The metal block with formed round holes served as a mold for the placement of the composite resin. The composite resin was cured with Penguin DB-685 lamp with four optional working modes: strong, low, gradually strong, and flashing. Unpolymerized part of the composite specimen was removed by scraping with a plastic spatula, and then each specimen was placed into the capsule with 1 ml of ethanol alcohol and mixed for 20 s in amalgamator. The length of the remaining composite specimen was measured with the digital caliper with a precision of 0.01 mm. The measured values were divided by 2 (according to ISO 4049 standard) and then statistically processed. Based on the measured lengths of the polymerized part of the composite specimens, the lowest average value of the depth of cure (2.75 ± 0.08 mm) was determined after polymerization with the low mode and the highest value was obtained (2.98 ± 0.08 mm) with strong polymerization mode. Statistically significant difference (p < 0.05) was determined between low polymerization mode and all other modes (strong, gradually strong and flashing mode). The observed statistically significant differences are not clinically important because all curing modes provided the necessary depth of cure, which is in accordance with the clinical recommendation of 2 mm thick composite layer.

Properties of New Glass-Ionomer Restorative Systems Marketed for Stress-Bearing Areas

2020 ◽  
Vol 45 (1) ◽  
pp. 104-110 ◽  
Author(s):  
D Fuhrmann ◽  
D Murchison ◽  
S Whipple ◽  
K Vandewalle
Keyword(s):  
Fracture Toughness ◽  
Composite Resin ◽  
Testing Machine ◽  
Surface Hardness ◽  
Glass Ionomer ◽  
Hardness Tester ◽  
Resin Coating ◽  
Significant Difference ◽  
Restorative Materials ◽  
Post Hoc

SUMMARY Objectives: The purpose of this study was to evaluate the properties (fracture toughness, surface hardness) of newer conventional glass-ionomer restorative materials that are marketed for posterior stress-bearing areas compared with more traditional glass-ionomer restorative materials marketed for non–load-bearing areas and composite-resin restorative materials. Methods and Materials: Notched-beam fracture toughness specimens were created in a mold with each tested material (Equia Forte, GC America, with and without a surface coating of Equia Forte Coat; Ketac Universal, 3M/ESPE; ChemFil Rock, Dentsply; Fuji IX GP Extra, GC; Ionostar Molar, VOCO; Filtek Z250, 3M/ESPE; Filtek Supreme Ultra, 3M/ESPE) and fractured using a universal testing machine after 24 hours of storage. Hardness values were determined on the surface of the fracture toughness specimens using a hardness tester. Data were analyzed with a one-way ANOVA and Tukey's post hoc test per property (alpha=0.05). Results: The composite-resin restorative materials had significantly greater fracture toughness than the glass-ionomer materials. There was no significant difference in fracture toughness between the glass-ionomer materials. The use of a resin coating significantly increased the surface hardness of the newer glass ionomer marketed for stress-bearing areas. Conclusions: Fracture toughness was not improved with the newer glass-ionomer restorative materials marketed for stress-bearing areas compared to the conventional glass-ionomer materials, however a resin coating provided greater surface hardness.

scholarly journals Analysis of the relationship between the surface hardness and Wear resistance of indirect composites used as veneer materials

2007 ◽  
Vol 18 (1) ◽  
pp. 60-64 ◽  
Author(s):  
Adriana Cláudia Lapria Faria ◽  
Ubiratan Menezes Benassi ◽  
Renata Cristina Silveira Rodrigues ◽  
Ricardo Faria Ribeiro ◽  
Maria da Gloria Chiarello de Mattos
Keyword(s):  
Wear Resistance ◽  
Water Immersion ◽  
Surface Hardness ◽  
Inverse Correlation ◽  
Test Surface ◽  
Immersion Period ◽  
Significant Difference ◽  
Indirect Composites ◽  
Light Curing ◽  
Unpaired Student

This study evaluated the surface hardness and wear resistance of indirect composites (Artglass and Solidex) and the existence of a correlation between these properties. Twenty-four specimens (12 per material) were fabricated using a polytetrafluoroethylene matrix (5.0 mm in diameter; 7.0 mm high) following an incremental technique. Polymerization was done with a xenon stroboscopic light curing unit. After polishing, the specimens were stored in water at 37°C during either 1 day (n=6 per material) or 55 days (n=6 per material), after which Vickers surface hardness and wear resistance were assessed. Data were analyzed statistically by unpaired Student t-test, two-way ANOVA and Tukey's test. Surface hardness. Artglass had higher surface hardness than Solidex after 1-day immersion period (p<0.01), but after 55 days there was no significant difference between the materials (p>0.05). Comparing the materials at both periods, Artglass means differed significantly to each other (p<0.01), while no significant difference was found between Solidex means (p>0.05). Wear resistance. Solidex had higher wear than Artglass after 1-day immersion period (p<0.01), but no significant difference was found between the materials after 55 days (p>0.05). Comparing the materials at both periods, Artglass means differed significantly to each other (p<0.01), with higher wear at 55-day period, but no difference was found between Solidex means (p>0.05). These results suggest that Artglass was better than Solidex in terms of hardness and wear resistance after 1-day water immersion. However, it was more susceptible to degradation, showing greater wear after 55 days. In conclusion, there was an inverse correlation between surface hardness and wear resistance for both Artglass and Solidex indirect composites, that is the higher the hardness, the lower the wear.

scholarly journals PREVALENCE OF HYPODERMA BOVIS AND THE ECONOMIC LOSSES CAUSED BY THE INFESTATION IN CATTLE HIDES

2003 ◽  
Vol 27 (1) ◽  
pp. 86-98
Author(s):  
Mohammed Awad Mallah ◽  
Raad Harbi Rahif
Keyword(s):  
Veterinary Medicine ◽  
High Intensity ◽  
Agricultural Research ◽  
Economic Losses ◽  
Low Intensity ◽  
Hypoderma Bovis ◽  
Significant Difference ◽  
Research Plan ◽  
College Farm ◽  
Low Rate

One thousand nine hundred thirty three cattle were examined, at age six months – eight years, slaughtered at Al-Shuala abattoir and market for selling the animals and also cows reared in 7 Nissan plan in Al-Ameria research plan belonging to IBA center for agricultural research, for a period extended from September 2001 until June 2002. The results of the study showed that the rate of infestation with Hypoderma bovis was 10.34% and the larvae were found in November and the higher rate of infestation was in December and reached 23.5%, while the lower rate was in May and reached 3.7%. Animals at age of 3-< 5.5 years showed the higher rate of infestation and reached 13.28% while others at age of 5.5 – 8 years showed the lower rate of infestation and reached 8.75% with significant difference (P< 0.05). The economic losses caused by infestation with Hypoderma bovis were evaluated. In Al-Shuala slaughterhouse infestation ranged from low intensity (1-5 bores) and it's higher rate was 25.9% in November, to moderate (6-10 bores) with the rate 13.9% and high (>10 bores) and its rate 6.3% in January. The over all losses were 859945.95Dinars. In Al-Karkch abattoir the higher rate of low intensity was 17% in January, the moderate infestation was 13.3% in November and the high intensity was 12.1% in January and the overall losses caused by different degree of infestation was 1177618.55 Dinars. A higher low rate 15%, moderate 10% and high 5% infestation were found in November and the overall losses reached 329450.75 Dinars .The study didn't show any losses in 7 Nissan and Al-Ameria Research plans and Veterinary Medicine College farm.

scholarly journals Influence of composite restorative materials and light-curing units on diametrical tensile strength

2005 ◽  
Vol 19 (2) ◽  
pp. 123-126 ◽  
Author(s):  
Maria Cecília Caldas Giorgi Tolosa ◽  
Luís Alexandre Maffei Sartini Paulillo ◽  
Marcelo Giannini ◽  
Alex José Souza dos Santos ◽  
Carlos Tadeu dos Santos Dias
Keyword(s):  
Tensile Strength ◽  
Light Emitting Diode ◽  
Resin Composite ◽  
Testing Machine ◽  
Internal Diameter ◽  
Dark Bottle ◽  
Halogen Light ◽  
Significant Difference ◽  
Restorative Materials ◽  
Light Curing

The aim of this study was to evaluate the diametrical tensile strength (DTS) of three light-curing photo-activated composites with two different light curing units (LCU). Three types of dental restorative composites were used in this study: micro filled A110 (3M Espe); P60 (3M Espe) for posterior restorations, and micro-hybrid Charisma (Heraeus-Kulzer). The two LCUs were: halogen light (HAL) (Degulux, Degussa) and blue light emitting diode (LED) (Ultrablue, DMC). Resin composite specimens were inserted incrementally into a Teflon split mold meas-uring 3 mm in depth and 6 mm in internal diameter, and cured using either LCU (n = 10). Specimens were placed into a dark bottle containing distilled water at 37°C for 7 days. DTS tests were performed in a Universal Testing Machine (0.5 mm/min). Data were submitted to two-way ANOVA and Tukey's test. Results were (MPa): A110/HAL: 276.50 ± 62.94ª; A110/LED: 306.01 ± 65.16ª; P60/HAL: 568.29 ± 60.77b and P60/LED: 543.01 ± 83.65b; Charisma/HAL: 430.94 ± 67.28c; Charisma/LED: 435.52 ± 105.12c. Results suggested that no significant difference in DTS was obtained with LCUs for the same composite. However, resin composite restorative materials presented different DTS.

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