scholarly journals Microleakage beneath Ceramic and Metal Brackets Photopolymerized with LED or Conventional Light Curing Units

2006 ◽  
Vol 76 (6) ◽  
pp. 1035-1040 ◽  
Author(s):  
Serdar Arıkan ◽  
Neslihan Arhun ◽  
Ayça Arman ◽  
Sevi Burcak Cehreli
Keyword(s):  
Light Emitting Diode ◽  
Light Emitting ◽  
Adhesive Interface ◽  
Group 4 ◽  
Quartz Tungsten Halogen ◽  
Ceramic Brackets ◽  
Light Curing ◽  
Group 3 ◽  
Group 2 ◽  
Ceramic Bracket

Abstract Objective: To test the null hypotheses that (1) the type of light curing unit used (quartz-tungsten-halogen [QTH] or light-emitting diode [LED]) would not affect the amount of microleakage observed beneath brackets, and (2) the bracket type used (ceramic or metal) would not influence the amount of microleakage observed beneath brackets. Materials and Methods: 40 freshly-extracted human premolars were randomly assigned into 4 bonding groups (n = 10/group): group 1, metal bracket + LED-cured Transbond XT; group 2, ceramic bracket + LED-cured Transbond XT; group 3, metal bracket + QTH-cured Transbond XT; and group 4, ceramic bracket + QTH-cured Transbond XT. The teeth were kept in distilled water for 1 month, and thereafter subjected to 500 thermal cycles. Then, specimens were sealed with nail varnish, stained with 0.5% basic fuchsin for 24 hours, sectioned, and photographed under a stereomicroscope. Microleakage was scored with regard to the adhesive-tooth interface and the bracket-adhesive interface at both incisal and gingival margins. Statistical analysis was accomplished by Kruskal-Wallis and Mann-Whitney U-tests with Bonferroni correction. Results: Microleakage was observed in all groups. When an LED curing unit was used for adhesive polymerization, ceramic brackets displayed significantly less microleakage than metal brackets in both tooth-adhesive and bracket-adhesive interfaces. When a QTH curing unit was used, ceramic brackets displayed significantly less microleakage than metal brackets in the bracket-adhesive interface in both gingival and incisal margins. Conclusions: Ceramic brackets cured with LED units were the best combination, demonstrating the lowest microleakage scores.

scholarly journals Microleakage beneath Ceramic and Metal Brackets Bonded with a Conventional and an Antibacterial Adhesive System

2006 ◽  
Vol 76 (6) ◽  
pp. 1028-1034 ◽  
Author(s):  
Neslihan Arhun ◽  
Ayca Arman ◽  
Sevi Burçak Çehreli ◽  
Serdar Arıkan ◽  
Erdem Karabulut ◽  
...  
Keyword(s):  
Adhesive System ◽  
White Spot Lesions ◽  
Adhesive Interface ◽  
Group 4 ◽  
Significant Difference ◽  
Ceramic Brackets ◽  
Group 3 ◽  
Group 2 ◽  
Ceramic Bracket ◽  
Nail Varnish

Abstract Objective: To assess microleakage of a tooth-adhesive-bracket complex when metal or ceramic brackets were bonded with a conventional and an antibacterial self-etching adhesive. Materials and Methods: Forty freshly extracted human premolars were randomly assigned to four equal groups and received the following treatments: group 1 = Transbond XT + metal bracket, group 2 = Transbond XT + ceramic bracket, group 3 = Clearfil Protect Bond + ceramic bracket, and group 4 = Clearfil Protect Bond + metal bracket. After photopolymerization, the teeth were kept in distilled water for 1 month and thereafter subjected to thermal cycling (500 cycles). Specimens were further sealed with nail varnish, stained with 0.5% basic fuchsin for 24 hours, sectioned and examined under a stereomicroscope, and scored for marginal microleakage for the adhesive-tooth and bracket-adhesive interfaces from incisal and gingival margins. Statistical analysis was accomplished by Kruskal-Wallis test and Mann-Whitney U-test with Bonferroni correction. Results: All groups demonstrated microleakage between the adhesive-enamel and bracket-adhesive interfaces. A significant difference was observed among all groups (P < .05) for the microleakage between the bracket-adhesive interface. Metal brackets exhibited significantly more microleakage than did ceramic brackets between the bracket-adhesive interface with either of the adhesives. Clearfil Protect Bond exhibited results similar to Transbond XT. Clearfil Protect Bond may be a choice of adhesive in bracket bonding because of its antibacterial activity and similar microleakage results with the orthodontic adhesive. Conclusions: Metal brackets cause more leakage between an adhesive-bracket interface, which may lead to lower clinical shear bond strength and white-spot lesions.

scholarly journals Microleakage under Metallic and Ceramic Brackets Bonded with Orthodontic Self-Etching Primer Systems

2008 ◽  
Vol 78 (6) ◽  
pp. 1089-1094 ◽  
Author(s):  
Tancan Uysal ◽  
Mustafa Ulker ◽  
Sabri Ilhan Ramoglu ◽  
Huseyin Ertas
Keyword(s):  
Stainless Steel ◽  
Phosphoric Acid ◽  
White Spot Lesions ◽  
Group 4 ◽  
Ceramic Brackets ◽  
Group 3 ◽  
Group 2 ◽  
Ceramic Bracket ◽  
Acid Gel

Abstract Objective: To compare the in vitro microleakage of orthodontic brackets (metal and ceramic) between enamel-adhesive and adhesive-bracket interfaces at the occlusal and gingival sides produced by self-etching primer system with that of conventional acid etching and bonding. Materials and Method: Sixty freshly extracted human mandibular premolar teeth were used in this study. The teeth were separated into four groups of 15 teeth each and received the following treatments: Group 1, 37% phosphoric acid gel + Transbond XT liquid primer + stainless steel bracket; Group 2, Transbond Plus Self-Etching Primer (TSEP) + stainless steel bracket; Group 3, 37% phosphoric acid gel + Transbond XT liquid primer + ceramic bracket; Group 4, TSEP + ceramic bracket. After curing, 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 occlusal and gingival margins. Statistical analyses were performed using Kruskal-Wallis and Mann-Whitney U tests. Results: The gingival sides in all groups exhibited higher microleakage scores compared with those observed in occlusal sides for both adhesive interfaces. Enamel-adhesive interfaces exhibited more microleakage than did the adhesive-bracket interfaces. Brackets bonded with self-etching primer system showed significantly higher microleakage at the enamel-adhesive interface of the gingival side. Conclusions: TSEP causes more microleakage between enamel-adhesive interfaces, which may lead to lower bond strength and/or white-spot lesions.

scholarly journals In vitro Evaluation of Microleakage under Ceramic and Metal Brackets Bonded with LED and Plasma Arc Curing

2012 ◽  
Vol 13 (5) ◽  
pp. 644-649
Author(s):  
Abdolrahim Davari ◽  
Soghra Yassaei ◽  
Mariam Karandish ◽  
Fateme Zarghami
Keyword(s):  
Light Emitting Diode ◽  
Plasma Arc ◽  
Light Emitting ◽  
Group Iii ◽  
Gingival Margin ◽  
Group I ◽  
Ceramic Brackets ◽  
Light Curing ◽  
Ceramic Bracket

ABSTRACT Aim The aim of the present study was to evaluate these two high intensity light curing units regarding microleakage beneath metal and ceramic brackets. Materials and methods A total of 60 freshly extracted human premolar teeth were randomly divided into four groups of 15 samples; group I: Metal bracket + LED cured, group II: Ceramic bracket + LED cured, group III: Metal bracket + plasma arc cured, group IV: Ceramic bracket + plasma arc cured. After photopolymerization, the teeth were immersed in water and thermocycled (500 cycles between 5 and 55). Specimens were further sealed with nail varnish and stained with 5% basic fuchsin for 24 hours. All of the teeth were sectioned with two parallel longitudinal occlusogingival cuts and examined under a stereomicroscope. The microleakage was measured with a digital caliper and scored from 0 to 3 for marginal microleakage at the bracket-adhesive and adhesive-enamel interfaces from both the occlusal and gingival margins. Results Microleakage was detected in all groups. The plasma arc cured group showed less microleakage than light emitting diode (LED) cured in all samples at the enamel-adhesive interface at the gingival margin (ceramic brackets, p = 0.009 and metal brackets, p = 0.005). The plasma arc cured samples showed less microleakage than LED cured in metal brackets at the adhesive-brackets interface at the occlusal margin (p = 0.033). While curing with an LED unit, ceramic brackets displayed significantly less microleakage than metal ones at the gingival margin of adhesive-enamel interface (p = 0.013). The gingival margin in all groups exhibited higher microleakage compared with those observed in occlusal sides in all sample groups (p < 0.001). Conclusion 1. LED units cause more microleakage than plasma arc units. 2. In all groups the microleakage at the gingival margin is greater than the occlusal margin. Clinical significance The microleakage formation permits the passage of bacteria and oral fluids initiating white spot lesions beneath the bracket base. How to cite this article Davari A, Yassaei S, Karandish M, Zarghami F. In vitro Evaluation of Microleakage under Ceramic and Metal Brackets Bonded with LED and Plasma Arc Curing. J Contemp Dent Pract 2012;13(5):644-649.

scholarly journals Comparison of effectiveness of light emitting diode phototherapy with conventional phototherapy and combination phototherapy of conventional with fiberoptic biliblanket, and light emitting diode phototherapy with fiber optic biliblanket for treatment of neonatal hyperbilirubinemia

2018 ◽  
Vol 5 (6) ◽  
pp. 2042
Author(s):  
Kamal K. Yenamandra ◽  
Rajesh Kumar ◽  
Ajoy K. Garg ◽  
Vivek Kumar ◽  
Daljit Singh
Keyword(s):  
Skin Rash ◽  
Fiber Optic ◽  
Light Emitting Diode ◽  
Light Emitting ◽  
Led Phototherapy ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Double Surface ◽  
Group 1

Background: Hyperbilirubinemia is a common problem in neonates with an incidence of 70-80%. Phototherapy is the preferred method of treatment for neonatal hyperbilirubinemia by virtue of its noninvasive nature and its safety. LED phototherapy, conventional phototherapy and fiber optic phototherapy are the modalities used in management of nonhemolytic hyperbilirubinemia in the first week of life in healthy near term and term neonates. The present study was conducted with the objective to compare effectiveness of double surface light emitting diode phototherapy with conventional double surface phototherapy and combination phototherapy of conventional and fiberoptic biliblanket, and light emitting diode phototherapy with fiber optic biliblanket for treatment of neonatal hyperbilirubinemia.Methods: Total of 236 neonates with hyperbilirubinemia were prospectively randomized to four groups to receive single surface conventional and fiber optic biliblanket combination phototherapy (n=60; Group-1), double surface LED phototherapy (n=59; Group-2), fiber optic biliblanket and single surface LED phototherapy groups (n=62; Group-3) and double surface conventional phototherapy group (n=55; Group-4). Bilirubin levels were measured at different time intervals and adverse effects were noted if any.Results: The rate of percentage and overall decrease of bilirubin was best in Group-2 (48.27%; 8.6 mg%) followed by Group-4 (45.49%; 8.1 mg%), Group-3 (41.26%; 7.27 mg%) and Group-1 (39.37%; 6.9 mg%). None of the babies presented side effects in Group-1 and Group-3. Neonates in Group-4 had shown loose stools (n=1), skin rash (n=3) and hyperthermia (n=2). Hyperthernia and skin rash was found in each case in Group-2.Conclusions: Rate of decrease of bilirubin was best in double surface LED phototherapy followed by double surface conventional phototherapy, fiber optic biliblanket with single surface LED combination phototherapy and fiber optic biliblanket and single surface conventional phototherapy.

scholarly journals Surface Hardness of Nanohybrid and Microhybrid Resin Composites Cured by Light Emitting Diode and Quartz Tungsten Halogen Light Curing Systems: An Invitro Study

2020 ◽  
Author(s):  
Anuradha Vitthal Wankhade ◽  
Sharad Basavraj Kamat ◽  
Santosh Irappa Hugar ◽  
Girish Shankar Nanjannawar ◽  
Sumit Balasaheb Vhate
Keyword(s):  
Light Emitting Diode ◽  
Surface Hardness ◽  
Composite Resins ◽  
Resin Composites ◽  
Light Emitting ◽  
Quartz Tungsten Halogen ◽  
Halogen Light ◽  
Intergroup Comparison ◽  
Light Curing ◽  
Curing Systems

Introduction: New generation composite resin materials have revolutionized the art of aesthetic dentistry. The clinical success is dependent on effective polymerisation and surface hardness which in turn are dependent on the performance of Light Curing Units (LCU). This study utilises surface hardness as a measure of degree of polymerisation of composite resins achieved by LCUs. Aim: To evaluate the difference in surface hardness of nanohybrid and microhybrid resin composites cured by light curing systems, Light Emitting Diode (LED) and Quartz Tungsten Halogen (QTH). Materials and Methods: In this invitro experimental study, two types of hybrid composites (Nanohybrid and Microhybrid) were tested for surface hardness by using two different light curing systems (LED and QTH). All the Nanohybrid and Microhybrid specimens were cured using LED and QTH LCUs, thus giving four combinations. A total of 60 specimens (6 mm diameter and 2 mm depth) were prepared using Teflon mould with 15 samples for each combination. Surface hardness was measured on upper and lower surface after 24 hours and hardness ratio was calculated. Data was analysed using independent t-test for intergroup comparison. Level of significance was kept at 5%. Results: Surface hardness of resin composites cured by LED LCU was greater than those cured by QTH LCU. Additionally, the hardness value was greater for the upper surface. Nanohybrids showed better surface hardness than Microhybrids for both the LCUs. Conclusion: Nanohybrid composite resins and LED system were found to be more effective in terms of surface hardness as compared to their counterparts.

scholarly journals Sorption, solubility and residual monomers of a dental adhesive cured by different light-curing units

2010 ◽  
Vol 21 (5) ◽  
pp. 432-438 ◽  
Author(s):  
Francine do Couto Lima Moreira ◽  
Nelson Roberto Antoniosi Filho ◽  
João Batista de Souza ◽  
Lawrence Gonzaga Lopes
Keyword(s):  
Light Source ◽  
High Performance ◽  
Light Emitting Diode ◽  
Single Bond ◽  
Light Emitting ◽  
Dental Adhesive ◽  
Quartz Tungsten Halogen ◽  
Light Curing ◽  
Storage Times ◽  
Curing Regimes

The aim of this study was to assess polymerization ability of three light-curing units by evaluating the influence of the light source, curing regimen and permeant (water or ethanol) on sorption, solubility and amount of residual monomers of a dental adhesive. Specimens of Adper Single Bond 2 were fabricated using a stainless steel circular matrix (8 mm x 1 mm). One quartz-tungsten-halogen (QTH) lamp and two light-emitting diode (LED) device at three different curing regimes (L1 = 12 J; L2 = 24 J; L3 = 24 J) were used to cure the specimens. Specimens were stored in two types of permeants - deionized water or 75% ethanol - for two storage times (G1 =7 days; G2 = 30 days). The specimens underwent water sorption and solubility tests, according to ISO 4049:2000 standard. After storage, residual monomers were identified and quantified by high performance liquid chromatography (HPLC). For sorption, L1 showed the highest values and QTH, the lowest. For solubility, in ethanol-stored groups, L1 had also the highest values, and QTH, the lowest, and findings were significantly different from the other curing regimens. L1 leached significantly more monomers than the others, and QTH had the lowest results. In conclusion, the type of light source, the curing regimen and the permeant affected sorption, solubility and amount of residual monomers of the adhesive under study.

scholarly journals Effect of the increase of energy density on knoop hardness of dental composites light-cured by conventional QTH, LED and xenon plasma arc

2005 ◽  
Vol 16 (3) ◽  
pp. 218-224 ◽  
Author(s):  
Américo Bortolazzo Correr ◽  
Mário Alexandre Coelho Sinhoreti ◽  
Lourenço Correr Sobrinho ◽  
Rubens Nisie Tango ◽  
Luis Felipe Jochims Schneider ◽  
...  
Keyword(s):  
Energy Density ◽  
Light Emitting Diode ◽  
Knoop Hardness ◽  
Composite Resins ◽  
Plasma Arc ◽  
Light Emitting ◽  
Quartz Tungsten Halogen ◽  
Light Curing ◽  
Cylindrical Cavities ◽  
Hardness Values

The aim of this study was to evaluate the effect of the increase of energy density on Knoop hardness of Z250 and Esthet-X composite resins. Cylindrical cavities (3 mm in diameter X 3 mm in depth) were prepared on the buccal surface of 144 bovine incisors. The composite resins were bulk-inserted and polymerized using different light-curing units and times: conventional QTH (quartz-tungsten-halogen; 700 mW/cm²; 20 s, 30 s and 40 s); LED (light-emitting diode; 440 mW/cm²; 20 s, 30 s and 40 s); PAC (xenon plasma arc; 1700 mW/cm²; 3 s, 4.5 s and 6 s). The specimens were stored at 37°C for 24 h prior to sectioning for Knoop hardness assessment. Three measurements were obtained for each depth: top surface, 1 mm and 2 mm. Data were analyzed statistically by ANOVA and Tukey's test (p<0.05). Regardless of the light source or energy density, Knoop hardness of Z250 was statistically significant higher than that of Esthet-X (p<0.05). Specimens cured with PAC had lower hardness than those cured with QTH and LED (p<0.05). Higher Knoop hardness was obtained when the energy density was increased for LED and PAC (p<0.05). No statistically significant differences (p>0.05) were found for QTH. Knoop hardness values decreased with the increase of depth. The increase of energy density produced composites with higher Knoop hardness means using LED and PAC.

scholarly journals Evaluation of Different Light-Curing Units—Light-Emitting Diodes and Quartz–Tungsten–Halogen-Based Light-Curing Units in Polymerization of Posterior Composite: An In Vitro Study

2018 ◽  
Vol 6 (02/03) ◽  
pp. 060-064
Author(s):  
R. Bansal ◽  
M. Bansal ◽  
S. Walia ◽  
C. Gupta ◽  
L. Bansal ◽  
...  
Keyword(s):  
Composite Resin ◽  
Light Emitting Diode ◽  
In Vitro Study ◽  
Hardness Test ◽  
Acrylic Resin ◽  
Halogen Lamp ◽  
Light Emitting ◽  
Quartz Tungsten Halogen ◽  
Light Curing

Abstract Objective To assess the adequacy of various light-curing units to polymerize the posterior composite resin. Materials and Methods Specimens were prepared by placing a single increment of posterior composite resin in split cylindrical metallic mold of dimension (6.0 mm in diameter and 5 mm in depth). Polymerization was done by utilizing one quartz-tungsten-halogen and three light-emitting diode light-curing units of different powers. The specimens of composite resin were then mounted on metallic molds utilizing autopolymerizing acrylic resin. After polishing, the complete setting of composite resin material was analyzed using Vickers hardness test. Results Showed in each group, hardness reduced as we moved from upper to lower surface of composite resin. Furthermore, hardness increased as intensity of light was increased. The maximum hardness was detected when light-emitting diode light-curing unit having intensity of 1,250 mW/cm2 was utilized and least hardness was detected when halogen lamp having intensity 418 mW/cm2 was utilized and results were found to be highly significant (p < 0.01). Conclusion It was concluded that increased top and bottom hardness can be accomplished by utilizing the light-curing unit of high intensity.

Composite Resin Microhardness: The Influence of Light Curing Method, Composite Shade, and Depth of Cure

2008 ◽  
Vol 9 (4) ◽  
pp. 43-50 ◽  
Author(s):  
Cesar Henrique Zanchi ◽  
Flávio Fernando Demarco ◽  
Camila Silveira de Araújo ◽  
Marcelo Thomé Schein ◽  
Sinval Adalberto Rodrigues
Keyword(s):  
Composite Resin ◽  
Light Emitting Diode ◽  
Curing Time ◽  
Light Emitting ◽  
Depth Of Cure ◽  
Quartz Tungsten Halogen ◽  
Light Curing ◽  
Curing Method ◽  
Hardness Values ◽  
Knoop Indenter

Abstract Aim The aim of this study was to investigate the influence of light curing method, composite shade, and depth of cure on composite microhardness. Methods and Materials Forty-eight specimens with 4 mm of depth were prepared with a hybrid composite (Filtek Z-100, 3M ESPE); 24 with shade A1 and the remaining with shade C2. For each shade, two light curing units (LCUs) were used: a quartz-tungsten-halogen (QTH) LCU (Optilight Plus - Gnatus) and a light emitting diode (LED) LCU (LEC 470 II - MM Optics). The LED LCU was tested using two exposure times (LED 40 seconds and LED 60 seconds). After 24-hour storage, three indentations were made at mm depth intervals using a Knoop indenter. Data were submitted to three-way analysis of variance (ANOVA) and Tukey's test (p<0.05). Results The three factors tested (light curing method, shade, and depth) had a significant influence on the composite microhardness (p<0.05). All groups presented similar hardness values in the first mm, except for composite shade C2 cured with LED for 40 seconds. The hardness decreased with depth, especially for shade C2 for 40 seconds. Increasing light-curing time with LED produced hardness values similar to the QTH. Conclusions The light curing method including variations of time, the depth of cure, and the composite shade influence the composite microhardness. Clinical Significance Clinicians should avoid thicker increments when working with composite restorations. Extended light-curing time might be indicated depending on the composite shade and on the light-curing device. Citation de Araújo CS, Schein MT, Zanchi CH, Rodrigues SA Jr, Demarco FF. Composite Resin Microhardness: The Influence of Light Curing Method, Composite Shade, and Depth of Cure. J Contemp Dent Pract 2008 May; (9)4:043-050.

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