Significant Difference In Dye Penetration Research Articles

Impact of radiotherapy and shielding on the efficacy of the self-etch adhesive technique.

Context:The exposure to gamma radiation affects the enamel and dentin in teeth restored with composite restoration, but a little has been done to protect from the detrimental effect.Aims:The aim of this in vitro study was to evaluate the effect of gamma radiation, with or without shielding (0.5 mm thickness of lead), in Class V cavities prepared on teeth exposed before and after restoration using the self-etch adhesive technique.Methods:A total of 75 intact teeth were selected. The samples were divided into five groups: Group I (15 teeth) not exposed to gamma radiation. Group II and III exposed to gamma radiation as per the standardized radiation protocol (2 Gy/day for 5 days/week = 10 Gy/week for 6 weeks = 60 Gy). Group III shielded, using a “0.5 mm thickness of lead” molded into a “C” shaped tube. Standardized Class V cavities were prepared on the buccal surface of all teeth and were restored by composite. Groups IV (not shielded) and V (shielded) were then exposed to standardized radiation protocol. All the samples were evaluated for the assessment of microleakage under stereomicroscope.Statistical Analysis Used:Statistics were tabulated using the Kruskal–Wallis ANOVA test.Results:Samples showed a significant difference in dye penetration scores.Conclusions:The samples restored before being exposed to gamma radiations performed better. Shielding with 0.5 mm of lead has shown increased efficacy of self-etch adhesive system irrespective of the stage of exposure.

An In Vitro Stereomicroscopic Evaluation of Bioactivity between Neo MTA Plus, Pro Root MTA, BIODENTINE & Glass Ionomer Cement Using Dye Penetration Method.

The ideal root end filling material should form a tight seal in the root canal by adhering to the cavity walls. Several materials have been used for root end filling. The present study aims to find out and compare the bioactivity of Neo MTA Plus, Pro Root MTA White, BIODENTINE & glass ionomer cement as root end filling materials using 1% methylene blue as tracer. Materials and methods: 80 extracted human permanent maxillary anterior teeth were used in the study. They were divided into four groups. Specimens were sectioned transversely in the cervical area to separate the crown from the root. The root canal was obturated with gutta percha and zinc oxide eugenol sealers. Thereafter, each sample was resected apically by removing 3 mm of the apex and filled with different materials. Samples were kept in buffering solution at 37 °C until the recommended evaluation periods. The specimens were then suspended in 1% methylene blue for 24 h, prior to the analysis. The teeth were then sectioned, and dye penetration was examined, photographed, and evaluated under a stereomicroscope. Results: Vertical dye penetration showed significant differences across different groups. The minimum dye penetration was seen in Neo MTA plus followed by BIODENTINE, Pro Root MTA and maximum in GIC. There was no significant difference in dye penetration between Neo MTA plus and BIODENTINE both at fifteen days and one-month intervals. Conclusion: The present study suggests Neo MTA plus and BIODENTINE should be the preferred material for root end filling.

Comparison of marginal microleakage of flowable composite restorations in primary canine teeth prepared with high-speed diamond bur, Er:YAG laser and Er,Cr:YSGG laser.

Adhesive restorations have become highly popular in pediatric dentistry, and novel methods of cavity preparation with minimal patient discomfort including Er:YAG and Er,Cr:YSGG laser preparations have greatly advanced. This study aimed to compare the microleakage of composite restorations of class V cavities prepared in primary canine teeth with high-speed bur and Er:YAG and Er,Cr:YSGG lasers. This in vitro study was conducted on 30 class V cavities prepared on the buccal surfaces of primary canine teeth in three groups (n = 10) of bur preparation, Er:YAG laser and Er,Cr:YSGG laser. The cavities were etched, bonded and restored with Grandio flowable composite according to the manufacturer's instructions. After thermocycling, the teeth were immersed in 1% methylene blue dye for 24 hours to detect microleakage. The teeth were evaluated under a stereomicroscope at ×32 magnification to assess the depth of penetration of methylene blue. The data were analyzed using SPSS version 19 and non-parametric Kruskal-Wallis and Mann Whitney tests. Non-parametric Kruskal-Wallis test showed no significant difference in dye penetration among the three groups (P > 0.05). Pairwise comparisons of occlusal and gingival margins by nonparametric Mann Whitney test revealed no significant difference in microleakage either (P > 0.05). Use of Er:YAG and Er,Cr:YSGG lasers can decrease microleakage to the level of bur preparation. Bur and laser cavity preparations are not significantly different in terms of microleakage at the enamel or dentin margins. Thus, considering the advantages of laser, it may serve as a suitable alternative to bur preparation in pediatric dentistry.

The effect of oxalate-based desensitizers on the microleakage and shear bond strength of resin modified glass ionomer.

BackgroundThe first line of intervention to alleviate tooth sensitivity is to use dentin desensitizers such as oxalate-based desensitizers. When the dentin sensitivity continues even after application of desensitizers the next intervention would be restoration of the lesion. The aim of this in vitro study was to investigate the effect of prior application of oxalate-based desensitizer on the marginal microleakage and shear bond strength of resin modified glass ionomer (RMGI) restorations.Material and MethodsIn order to prepare the specimens for microleakage test standard class v cavities were prepared on buccal surfaces of 45 teeth. The specimens were randomly divided into three equal groups. In control group, the cavities were restored with RMGI. In group 2, oxalate-based desensitizer was applied and the specimens were kept in distilled water for 14 days before restoration. In group 3 the specimens were prepared similar to group 2 and the surface of the cavities were slightly cut with bur before restoration. Methyleneblue penetration was evaluated using stereomicroscope. The data were analyzed using non-parametric tests. For shear bond strength test cervical dentin specimens were prepared and were divided into 3 groups. Surface treatments were similar to microleakage test. RMGI was packed into cylindrical plastic molds which were placed on the cut surface of the tooth and light cured. The data were analyzed by one-way ANOVA.ResultsThere was not any significant difference in dye penetration in dentin margins among the groups, but microleakage in enamel margins of group 2 and 3 was higher than group 1. There was no significant difference in shear bond strength among the groups (p =0.285).ConclusionsNon carious cervical lesions which were treated for hypersensitivity with oxalate-based desensitizers could be restored with resin modified glass ionomer if the hypersensitivity persists. Key words:Dentin hypersensitivity, oxalate-based desensitizers, microleakage, shear bond strength.

Evaluation of microleakage in class V composite restorations using dye penetration and micro-CT.

The aim of this study was the evaluation of microleakage in class V cavities using micro-CT imaging and dye penetration. Sixty class V cavities were prepared, randomly divided into five groups (Adper Single Bond Plus (ASB), ExciTE (EX), iBond TE (ITE), Optibond Solo Plus (OSP), Prime & Bond NT (PB)) and restored with Venus Diamond. After thermocycling and dye penetration test with 50wt% ammoniacal silver nitrate, eight samples per group were sectioned longitudinally and evaluated under a coaxial incident light microscope (enamel (E) and dentin (D) measurement in mm). The remaining samples were analyzed by counting voids in the coronal and cervical adhesive areas by means of micro-CT. In dentin, no statistically significant difference in dye penetration was found. In enamel, OSP showed significant higher microleakage than all other adhesives (p<0.001). Groups ITE, ASB, PB, and EX showed a significantly lower penetration depth in E than in D (p<0.001). The results of the micro-CT examination in dentin are contrary to the findings of the microleakage evaluation. Regarding enamel, only group PB showed significant more voids than EX in enamel (p<0.02). Within the adhesive groups, PB showed significantly more voids in E than in D (p<0.04). This test method must be optimized by developing a new leakage tracer for a better differentiation between hard tissues and dental materials. The micro-CT is not yet a vulnerable tool to evaluate the marginal integrity of resin composites.

FISSURE SEALANT INTERFACE MICROLEAKAGE USING ONE STEP ADHESIVES

Background:This study evaluated the efficacy of a one step adhesives in reducing microleakage after water storage and thermocycling. Method: eighteen freshly extracted caries-free human premolars were used. The teeth were randomly divided into two groups; Group I: control etch adhesive (GC),Group II: G Bond One step adhesive (GC) The teeth were restored using helioseal Vivadent. Group II Each layer was cured using the Spectrum 800 curing light (Dentsply/Caulk) for 20 seconds at 600mW/cm2. The teeth were stored in artifisial saliva for 7 days in incubator. Samples were thermocycled 250x between 5°C and 55°C with a dwell of 30 seconds, then placed in a 0.5% methylene blue dye solution for 24 hours at 37°C. Samples were sectioned longitudinally and evaluated for microleakage at the occlusal and gingival margins under a microscope at 40x magnification. Dye penetration was scored: 0: no microleakage visible, score 1: microleakage up to half of the fissure, score 2: microleakage more than half of the fissure. Result: Mann-Whitney test was used to demonstrate significantly more dye penetration in Group I and Group II. When comparing the scores for two group, the Mann Whitney test showed no significant difference in dye penetration for etch and One step adhesive (p&gt;0.05). Conclusion: Based on the results of this study, it can be concluded that etch and one step adhesive in the fissure sealant no significant difference to reduce of microleakage in study in vitro.

The Effect of Two Bulk Fill Resin Composites on Microleakage in Endodontically Treated Teeth

Purpose: To evaluate the effect of two bulk fill resin composites on microleakage in endodontically treated Class II restorations. Materials and Methods: Twenty-four non-carious molars were selected and randomly divided into three groups (n = 8). The Class II cavity preparations were made with the cervical margin 1 mm below the cementum-enamel junction, and endodontic treatment was performed using a resin-based sealer and gutta-percha points. In Group 1 (Control), resin composite (G-aenial Posterior; GC Corp., Tokyo, Japan) was applied to the interproximal wall, and then restorative material was applied incrementally. In Group 2, resin composite was applied to the interproximal wall, followed by a 4-mm-layer of a bulk fill flowable composite (x-tra base; Voco, GmbH, Cuxhaven, Germany) and the remaining occlusal part of the cavity was filled with resin composite. In Group 3, resin composite was applied to the interproximal wall, followed by a 4mm layer of a bulk fill fiber-reinforced composite (everX Posterior; GC Corp., Tokyo, Japan), and the remaining occlusal part of the cavity was filled with a resin composite. The restorations were then subjected to 500 thermal cycles, each with a dwell time of 20 seconds at 5 and 55 oC. The adaptation at the cervical margin was evaluated by dye penetration, and one tooth was used to evaluate the restorative material interface using SEM. The data were statistically analyzed using the Kruskal Wallis test (p &lt; 0.05). Results: No significant difference in dye penetration was found between the control and the experimental groups. Microleakage was significantly higher on enamel margins compared with the dentin margins for all of the groups. Conclusion: The use of bulk fill restorative materials under resin composites does not affect the sealing ability of restorations.

The effect of a new-generation flowable composite resin on microleakage in Class V composite restorations as an intermediate layer

Aim:To evaluate the effect of application a new-generation bulk-fill flowable composite resin as an intermediate material between composite resin and dental substrates on micro-leakage in Class V composite restorations.Materials and Methods:A total of 144 Class V cavities were prepared in 72 human molars. Specimens were then randomly distributed among three groups according to adhesive system applied (Group 1: Clearfil SE Bond; Group 2: Adper Easy One; Group 3: Adhesive 200T), and each group was divided into three subgroups according to liner material used (Group A: No liner-control group; Group B: Aelite Flo LV, low viscosity microhybrid composite; Group C: Smart dentin replacement). All cavities were restored using resin composite (Aelite LS, low shrinkage posterior composite). Specimens were stained with 0.5% basic fuchsin and evaluated dye penetration.Results:There was no significant difference in dye penetration was found between the control and the experimental groups.Conclusions:Micro-leakage is not affected by the application of either conventional or new-generation flowable composite resin as an intermediate material between composite resin and dental substrates.

Comparison of Sealing Ability of Lateral and Vertical Techniques in Two Different Post Space Preparations

INTRODUCTION: The purpose of this study was to compare the apical sealing ability of lateral and vertical compaction techniques following immediate and delayed post space preparation. MATERIALS AND METHODS: Seventy-four distal and palatal roots of human extracted molars were instrumented and randomly divided into 4 experimental groups (n=15), two experimental control groups (n=5), and two positive and negative leakage controls (n=2). Canals were filled by lateral (groups 1 and 2) and vertical (groups 3 and 4) compaction techniques using Tubliseal sealer. Post space was prepared immediately after obturation in group 1 and after seven days in groups 2 and 4 using a # 3 Peeso drill. In group 3, post space was prepared immediately during down-packing phase. The teeth were kept in 2% methylen blue dye for seven days. The roots were sectioned buccolingually and the mean score of dye penetration was measured. Data was analyzed with T-test and one way ANOVA. RESULTS: There was significant difference in dye penetration between delayed and control-lateral compaction groups ( p =0.009). There was also a significant difference in dye penetration between immediate and delayed lateral compaction groups ( p =0.044). CONCLUSION: Less apical leakage in the cold lateral condensation and immediate post space preparation group was observed.

The Effect of CO2Laser on the Permeability of Dentinal Tubules: A Preliminaryin VitroStudy

The purpose of this in vitro study was to determine whether there is a change in dentin permeability following 9.6-microm CO(2) laser irradiation and high-speed drilling. Twenty permanent, intact, non-carious molars were selected. The crowns were separated from the roots at the cemento-enamel junction. The teeth were randomly divided into two groups, control and experimental, each containing 10 teeth. After class I preparation using a high-speed drill, 9.6-microm CO(2) laser irradiation was applied to dentinal areas only on the experimental group. The samples were soaked in 0.5% methylene blue for 48 h; three independent examiners using scanning electron microscopy evaluated dye penetration through the specimens. The results of the three examiners were similar. There was a significant difference in dye penetration into dentin after laser irradiation versus controls (p < 0.05). The 9.6-microm CO(2) laser appears to be a promising tool in the clinical setting. However, further investigation is needed to ensure maximum effectiveness.

An in vitro investigation of a comparison of bond strengths of composite to etched and air-abraded human enamel surfaces

Purpose The purposes of the study were to measure the tensile bond strength of composite resin to human enamel specimens that had been either etched or air-abraded, and to compare the quality of the marginal seal, through the assessment of microleakage, of composite resin to human enamel specimens that had been either etched or air-abraded. Materials and methods Thirty mandibular molar teeth were decoronated and sectioned mesio-distally to produce six groups, each containing ten specimens that were embedded in acrylic resin using a jig. In each of the four treatment groups, the specimen surfaces were treated by either abrasion with 27 or 50 microm alumina at 4 mm or 20 mm distance, and a composite resin was bonded to the treated surfaces in a standardized manner. In the two control groups the specimens were treated with 15 seconds exposure to 36% phosphoric acid gel and then similarly treated before being stored in sterile water for 1 week. All specimens were then subjected to tensile bond strength testing at either 1 or 5 mm/min crosshead speed. For the microleakage study, the degree of dye penetration was measured 32 times for each treatment group, using a neutral methylene blue dye at the interface between composite and either 27 or 50 microm air-abraded tooth structure or etched enamel surfaces. Results The mean bond strength values recorded for Group 1 (phosphoric acid etch, 5 mm/min crosshead speed) was 25.4 MPa; Group 2 (phosphoric acid etch, 1 mm/min), 22.2 MPa; Group 3 (27 microm alumina at 4 mm distance), 16.8 MPa; Group 4 (50 microm alumina at 4 mm distance), 16.9 MPa; Group 5 (27 microm alumina at 20 mm distance), 4.2 MPa; and for Group 6 (50 microm alumina at 20 mm distance) 3.4 MPa. An analysis of variance (ANOVA) demonstrated significant differences among the groups, and a multiple comparison test (Tukey) demonstrated that conventionally etched specimens had a greater bond strength than air-abraded specimen groups. No significant difference in dye penetration could be demonstrated among the groups (p= 0.58). Conclusions Composite resin applied to enamel surfaces prepared using an acid etch procedure exhibited higher bond strengths than those prepared with air abrasion technology. The abrasion particle size did not affect the bond strength produced, but the latter was adversely affected by the distance of the air abrasion nozzle from the enamel surface. The crosshead speed of the bond testing apparatus had no effect on the bond strengths recorded. The marginal seal of composite to prepared enamel was unaffected by the method of enamel preparation.

An In Vitro Investigation of a Comparison of Bond Strengths of Composite to Etched and Air‐Abraded Human Enamel Surfaces

The purposes of the study were to measure the tensile bond strength of composite resin to human enamel specimens that had been either etched or air-abraded, and to compare the quality of the marginal seal, through the assessment of microleakage, of composite resin to human enamel specimens that had been either etched or air-abraded. Thirty mandibular molar teeth were decoronated and sectioned mesio-distally to produce six groups, each containing ten specimens that were embedded in acrylic resin using a jig. In each of the four treatment groups, the specimen surfaces were treated by either abrasion with 27 or 50 microm alumina at 4 mm or 20 mm distance, and a composite resin was bonded to the treated surfaces in a standardized manner. In the two control groups the specimens were treated with 15 seconds exposure to 36% phosphoric acid gel and then similarly treated before being stored in sterile water for 1 week. All specimens were then subjected to tensile bond strength testing at either 1 or 5 mm/min crosshead speed. For the microleakage study, the degree of dye penetration was measured 32 times for each treatment group, using a neutral methylene blue dye at the interface between composite and either 27 or 50 microm air-abraded tooth structure or etched enamel surfaces. The mean bond strength values recorded for Group 1 (phosphoric acid etch, 5 mm/min crosshead speed) was 25.4 MPa; Group 2 (phosphoric acid etch, 1 mm/min), 22.2 MPa; Group 3 (27 microm alumina at 4 mm distance), 16.8 MPa; Group 4 (50 microm alumina at 4 mm distance), 16.9 MPa; Group 5 (27 microm alumina at 20 mm distance), 4.2 MPa; and for Group 6 (50 microm alumina at 20 mm distance) 3.4 MPa. An analysis of variance (ANOVA) demonstrated significant differences among the groups, and a multiple comparison test (Tukey) demonstrated that conventionally etched specimens had a greater bond strength than air-abraded specimen groups. No significant difference in dye penetration could be demonstrated among the groups (p= 0.58). Composite resin applied to enamel surfaces prepared using an acid etch procedure exhibited higher bond strengths than those prepared with air abrasion technology. The abrasion particle size did not affect the bond strength produced, but the latter was adversely affected by the distance of the air abrasion nozzle from the enamel surface. The crosshead speed of the bond testing apparatus had no effect on the bond strengths recorded. The marginal seal of composite to prepared enamel was unaffected by the method of enamel preparation.

A microleakage study of single-bottle adhesives applied to enamel and cementum and aged by both occlusal loading and thermocycling

Objective To compare enamel and dentin microleakage of three single-bottle dentin-bonding agents (DBA) (One-Step, Single Bond, and Dentamed P&B) on teeth that were then subjected to thermocycling and occlusal loading. Method and Materials Class 5 cavities were prepared on the buccal and lingual surfaces of 30 extracted human molars and divided into three groups. The occlusal margins were in enamel, and the cervical margins were in cementum. DBA were applied strictly according to the manufacturers' recommendations, and the preparations were restored with resin composite. Specimens were subjected to 2,000 intermittent occlusal loads and 3,000 thermocycles and then immersed in 0.5% basic fuchsin dye for 72 hours. Four consecutive sections were cut for each specimen and examined under a stereomicroscope. The extent of dye penetration was measured and recorded using a nonparametric scale from 0 to 4. Results The Mann-Whitney U test showed a significant difference at cementum margins between One-Step and Dentamed P&B, as well as between Single Bond and Dentamed P&B, and an insignificant difference between Single Bond and One-Step. There was no significant difference in dye penetration at enamel margins between the three DBA. Conclusion Under combined use of occlusal loads and thermocycling, the sealing ability of single-bottle DBA at dentin margins ranged from good for One-Step to moderate for Single Bond to poor for Dentamed P&B. At enamel margins, all materials performed equally well.—Reprinted with permission of Quintessence Publishing. To compare enamel and dentin microleakage of three single-bottle dentin-bonding agents (DBA) (One-Step, Single Bond, and Dentamed P&B) on teeth that were then subjected to thermocycling and occlusal loading. Class 5 cavities were prepared on the buccal and lingual surfaces of 30 extracted human molars and divided into three groups. The occlusal margins were in enamel, and the cervical margins were in cementum. DBA were applied strictly according to the manufacturers' recommendations, and the preparations were restored with resin composite. Specimens were subjected to 2,000 intermittent occlusal loads and 3,000 thermocycles and then immersed in 0.5% basic fuchsin dye for 72 hours. Four consecutive sections were cut for each specimen and examined under a stereomicroscope. The extent of dye penetration was measured and recorded using a nonparametric scale from 0 to 4. The Mann-Whitney U test showed a significant difference at cementum margins between One-Step and Dentamed P&B, as well as between Single Bond and Dentamed P&B, and an insignificant difference between Single Bond and One-Step. There was no significant difference in dye penetration at enamel margins between the three DBA. Under combined use of occlusal loads and thermocycling, the sealing ability of single-bottle DBA at dentin margins ranged from good for One-Step to moderate for Single Bond to poor for Dentamed P&B. At enamel margins, all materials performed equally well.—Reprinted with permission of Quintessence Publishing.

An in vitro study of the quality of root fillings in teeth obturated by lateral condensation of gutta‐percha or Thermafil obturators

The aim of this in vitro study was to assess the quality of root canal obturation and degree of linear apical dye penetration in teeth root filled with either laterally condensed gutta-percha or Thermafil obturators. A total of 150 teeth with single roots were included in the study. All canals were prepared using a standard step-back technique with anticurvature filing. Radiographs taken of the teeth to show the maximum degree of canal curvature were then exposed and the angle, radius and position of curvature determined. This information about the canals, together with their working length and diameter at end-point, was used to divide the teeth into two experimental and two control groups. A total of eight teeth were excluded because of technical difficulties, 65 were filled with Thermafil obturators, 63 were filled with laterally condensed gutta-percha whilst 14 teeth remained unfilled and acted as controls. Following obturation, the teeth were radiographed in two planes and the technical quality of fill assessed on a four-point scale. All access cavities were then sealed and the teeth immersed in dye for 48 h before being split longitudinally. Linear dye penetration via the apical foramen was then assessed. Canal obturation with Thermafil obturators (0.7 min) was significantly quicker (P < 0.001) than lateral condensation (6.4 min). Apical extrusion of sealer and gutta-percha occurred significantly more often with Thermafil obturators but there was little difference in the technical quality of the fillings and no significant difference in dye penetration. Under the conditions of this study. Thermafil obturators proved a satisfactory alternative to lateral condensation of gutta-percha.