Difference In Microleakage Research Articles

Assessment of Microleakage of a Composite Resin Restoration in Primary Teeth Following Class III Cavity Preparation Using Er, Cr: YSGG laser: An In Vitro Study.

Introduction: Marginal seal integrity is important for a successful adhesive dental restoration. Alterations caused by laser irradiation in the enamel and dentin surface can affect the marginal integrity of adhesive restorations. The aim of this study was to evaluate the microleakage of a composite resin restoration in primary teeth following laser irradiation of enamel and dentin. Methods: Forty freshly extracted sound human primary maxillary and mandibular anterior teeth were used in this study. The teeth were randomly divided into two groups (I and II), with 20 teeth in each. In group I, proximal cavities (Class III) were prepared using an airotor hand -piece and diamond bur. The cavities were etched for 15 seconds with 35% phosphoric acid gel, rinsed with water for 15 seconds, air dried and a bonding agent was applied onto the cavity surfaces and light cured for 20 seconds. The cavities were restored with composite resin and light cured for 40 seconds. In group II, proximal (Class III) cavities were prepared using Erbium, Chromium: Yttrium Scandium Gallium Garnet (Er,Cr:YSGG) (Er,Cr:YSGG) (Biolaseiplus, wave length 2.78 μm). The cavity was then rinsed, air dried and without etching, a bonding agent was applied and light cured for 20 seconds. The cavities were restored in the same manner as that of group I. The treated teeth were mounted on acrylic resin blocks and were subjected to a thermocycling regimen. Following, the teeth were immersed in 2% methylene blue for 24 hours. The teeth were sectioned longitudinally in a bucco-lingual direction using a diamond disc at slow speed. The sections of all the groups were examined under a stereomicroscope for micro-leakage. Results: The mean scores for microleakage in group I was 1.95 ± 1.31 and in group II it was 1.4 ± 1.27. There was no significant difference between the two groups (P = 0.882). Conclusion: No significant difference in microleakage was noticed between the composite resin bonded to lased enamel and dentin and the teeth preparedwith conventional method.

Effect of desensitizers on the microleakage of previously restored Class V resin composite restorations

Objectives: The aim of this in vitro study was to evaluate the effect of different desensitizers’ application on the microleakage of previously restored Class V composite resin restorations.Materials and methods: Class V cavities were prepared on the buccal surfaces of 40 extracted human third molars. Forty box-shaped cavities were divided into four groups, based on the desensitizers used (n = 10). All teeth were restored with the same bonding agent and composite material. No desensitizer was applied in the control group. In the experimental groups, BisBlock, Gluma and Universal bonding agents were the desensitizers. The desensitizers were applied after completion of composite restorations according to manufacturers’ instructions. All specimens were then thermocycled at 5–55 °C, with a 10-s dwell time for 500 cycles. The samples were then immersed in 0.5% methylene blue dye for 24 h, sectioned into two equal halves, evaluated for microleakage using a stereomicroscope at 30× magnification and scored on a scale of 0–3. The data were analysed using the Kruskal–Wallis test at the significance level p < 0.05.Results: There were no significant differences in microleakage after desensitizer application (p > 0.05). However, based on the obtained numerical values in our study, while the BisBlock and bonding groups showed lower microleakage at the occlusal margin, BisBlock, Gluma and bonding group showed lower microleakage at the gingival margin compared to the control group.Conclusions: The application of desensitizers as a post-treatment option could be considered an advisable procedure to minimize microleakage.

The impact of Er:YAG laser enamel conditioning on the microleakage of a new hydrophilic sealant--UltraSeal XT hydro.

UltraSeal XT® hydro™ is a new hydrophilic, light-cured, methacrylate-based pit and fissure sealant which has been developed by Ultradent Products, USA. The sealant is highly filled with a 53 wt.% mixture of inorganic particles which confer both thixotropy and radiopacity. The principal purpose of this study was to investigate the microleakage of UltraSeal XT® hydro™ as a function of different enamel etching techniques. The occlusal surfaces of sound, extracted human molars were either acid etched, Er:YAG laser irradiated or successively laser irradiated and acid etched. UltraSeal XT® hydro™ was applied to each group of teeth (n = 10) which were subjected to a thermocycling process consisting of 2500 cycles between 5 and 50 °C with a dwell time of 30 s. Microleakage assessments were then carried out using 0.5 % fuchsin dye and optical microscopy. The microleakage score data were analysed using the Kruskal-Wallis, Mann–Whitney U test with Bonferroni adjustment. No significant differences in microleakage were noted between the individually acid etched and laser-irradiated groups (p > 0.05); however, teeth treated with a combination of laser irradiation and acid etching demonstrated significantly lower microleakage scores (p < 0.001). Electron microscopy with energy-dispersive X-ray analysis revealed that the mineral filler component of UltraSeal XT® hydro™ essentially comprises micrometre-sized particles of inorganic silicon-, aluminium- and barium-bearing phases. Laser etching increases the roughness of the enamel surface which causes a concentrated zoning of the filler particles at the enamel-sealant interface.

Comparative evaluation of microleakage using three variables of glass-ionomer cement in primary and permanent teeth: An in vitro study

Background and Objective: Since their invention in 1970, glass-ionomer cements (GICs) have been widely used in pediatric dentistry. They have undergone many modifications in composition till the recent nano cement which claims to have superior properties compared to their primal versions. One of the important requisites of restorative material is adhesion to the tooth structure, failure of which leads to microleakage. Hence, the main objective of this study was to compare the microleakage of three variables (Ketac Molar, Ketac Silver, Ketac N100) of GIC in primary and permanent posterior teeth. Materials and Methods: Class I occlusal cavities were prepared on 60 extracted, noncarious primary molars and premolars. Each set of dentition (primary and permanent teeth) was divided into three groups of 10 specimens each to restore with the selected restorative material - Group A (Ketac Molar), Group B (Ketac Silver), and Group C (Ketac N100). These teeth were subjected to thermocycling, dye immersion, sectioning, and examination was done under a stereomicroscope to assess the degree of microleakage. The scoring was done according to the scoring criteria put forward by Khera and Chan, which were further tabulated and statistically analyzed. Results: There was no significant difference in microleakage between primary and permanent teeth in all the three groups. In both primary and permanent teeth, Group B showed significantly higher dye penetration scores followed by Groups A and C. Conclusion: The nano-filled resin-modified GIC (Ketac N100) proved to be the better restorative material than the other cements used in the study. Clinical Relevance To Interdisciplinary Dentistry Microleakage is the most common cause of failure for all restorative materials, since it is a major contributing factor to secondary caries and early pulpal involvement. Consequently, an interest arises in finding a restorative material which has better bonding with the dental tissues thereby minimizing the chances of microleakage. Nano-filled RMGIC is found to be a good restorative material in maintaining the longevity of the restoration both in primary and permanent dentition.

Microleakage in Class V Composite Restorations after Desensitizing Surface Treatment with Er:YAG and CO2 Lasers

Aims: Glutaraldehyde, CO2 and Er:YAG lasers can be used for treatment of dentin hypersensitivity. However, their application may have adverse effects on the clinical service of restorations. This study aimed to assess the microleakage in composite restorations following surface treatment with Glutaraldehyde desensitizer, CO2 and Er:YAG laser irradiation for treatment of dentin hypersensitivity. Materials and methods: This experimental study was conducted on 60 extracted sound human teeth. Class V cavities were prepared measuring 3×3 mm using a diamond bur. Specimens were randomly divided into 4 groups of 15. Group one:no surface treatment, Group two:applying Glutaraldehyde desensitizer, Groups of three and four were irradiated with CO2 and Er:YAG lasers, respectively. Surfaces were restored with bonding agent (Single Bond 2, 3M, USA) and Z250 composite (3M, USA). Specimens were thermocycled and immersed in 1% methylene blue solution for 24 hours. Microleakage scores were assessed under a stereomicroscope at ×20 magnification. Data were analyzed using SPSS and the Kruskal Wallis test (P=0.05). Results: There was no significant difference between microleakage of groups in enamel margins (P=0.694). The difference in microleakage at the dentin margin was significant between groups (P=0.018). Conclusions: Application of Glutaraldehyde-desensitizer and CO2 laser irradiation of surfaces prior to composite restoration do not increase microleakage at the enamel or dentin margins but tooth surface treatment with Er:YAG laser significantly increased the microleakage at the dentin margins.

A comparison of apical sealing ability between GuttaFlow and AH plus: An in vitro study.

Aims:The present study aimed to compare apical sealing ability between GuttaFlow and AH Plus.Materials and Method:Eighty extracted human maxillary anterior teeth with fully formed apex and straight root were collected for this study. The root canals were cleaned and shaped using a standard step back preparation to size 60# master apical file at the established working length and divided into four groups: Group 1, GuttaFlow sealer with gutta-percha; Group 2, AH Plus sealer with gutta-percha; Group 3, positive control group (Teeth were instrumented and left without obturation); Group 4, negative control group (Teeth were totally coated with nail varnish) Dye leakage was carried out. Statistical analysis was done using the Statistical Package for the Social Sciences software and Student's unpaired t-test.Results:The GuttaFlow group had a mean leakage of 1.38 mm whereas AH Plus had a mean of 1.425 mm. The standard deviation of GuttaFlow and AH Plus were 0.3861 and 0.3226, respectively. Student's unpaired t-test disclosed no significant difference (P < 0.05) between the groups.Conclusion:None of the sealers used in the study could completely seal the apical foramen to have a fluid-tight seal. GuttaFlow and AH Plus showed no statistically significant difference in microleakage; the better result was shown by GuttaFlow.

Sealing of adhesive systems in ferric sulfate-contaminated dentinal margins in class V composite resin restorations.

Background. Hemostatic agents are applied to prepare an isolated bleeding-free condition during dental treatments and can influence adhesive restorations. This study evaluated the effect of a hemostatic agent (ViscoStat) on microleakage of contaminated dentinal margin of class V composite resin restorations with three adhesives.Methods. Sixty freshly extracted human molars were selected and class V cavities (3×3×1.5 mm) were prepared on buccal and lingual surfaces. Gingival margins of the cavities were placed below the cementoenamel junction. The teeth were divided into six groups randomly. The adhesives were Excite, AdheSE and AdheSE One. In three groups, the gingival walls of the cavities were contaminated with ViscoStat and then rinsed. The cavities were restored with composite resin and light-cured. After storage in distilled water (37°C) for 24 hours and polishing, the samples were thermocycled and sealed with nail varnish. Then they were stored in 1% basic fuchsin for 24 hours, rinsed and mounted in self-cured acryl resin, followed by sectioning buccolingually. Dye penetration was observed under a stereomicroscope and scored. Data were statistically analyzed with Kruskal-Wallis and Mann-Whitney U tests. P<0.05 was set as the level of significance.Results. Only in the Excite group, contamination did not have adverse effects on dentin microleakage (P > 0.05). In the contaminated groups, Excite had significantly less microleakage than the others (P = 0.003). AdheSE and AdheSE One did not exhibit significant difference in microleakage (P > 0.05).Conclusion. ViscoStat hemostatic agent increased dentinal microleakage in AdheSE and AdheSE One adhesives with no effect on Excite.

Microleakage evaluation of class II composite restoration with incremental and bulk fill technique

Introduction: Microleakage has been regarded as a primary concern of use of composites in class II cavity restorations. Many products have attempted to minimize the interfacial gap between the tooth and restoration, the main pathway of microleakage. The aim of this in-vitro study is to quantitatively evaluate the microleakage of class II composite restoration done with incremental and bulk fill technique. Materials and Methods: In an in-vitro study, a total of 40 sound extracted molars were used for class II preparations and restoration with incremental (Group I, 20 teeth) and bulk fill technique (Group II, 20 teeth). Samples were accessed for dye penetration and pairwise comparison was done using Wilcoxon rank test. Results: Both the composite insertion techniques were not able to completely eliminate the microleakage. Two specimens of bulk filling technique show microleakage, extending to the axial wall. There is no statistically significant difference in microleakage irrespective of the insertion technique used. Conclusion: It can be concluded from the results that there is no significant difference in microleakage for composite restorations done by a bulk layering technique using the newer generation composites and the conventional incremental layering technique.

Microleakage of Four Dental Cements in Metal Ceramic Restorations With Open Margins.

Background:Fixed prosthodontics is a routine dental treatment and microleakage is a major cause of its failure.Objectives:The aim of this study was to assess the marginal microleakage of four cements in metal ceramic restorations with adapted and open margins.Materials and Methods:Sixty sound human premolars were selected for this experimental study performed in Tehran, Iran and prepared for full-crown restorations. Wax patterns were formed leaving a 300 µm gap on one of the proximal margins. The crowns were cast and the samples were randomly divided into four groups based on the cement used. Copings were cemented using zinc phosphate cement (Fleck), Fuji Plus resin-modified glass ionomer, Panavia F2.0 resin cement, or G-Cem resin cement, according to the manufacturers’ instructions. Samples were immersed in 2% methylene blue solution. After 24 hours, dye penetration was assessed under a stereomicroscope and analyzed using the respective software. Data were analyzed using ANOVA, paired t-tests, and Kruskal-Wallis, Wilcoxon, and Mann-Whitney tests.Results:The least microleakage occurred in the Panavia F2.0 group (closed margin, 0.18 mm; open margin, 0.64 mm) and the maximum was observed in the Fleck group (closed margin, 1.92 mm; open margin, 3.32 mm). The Fleck group displayed significantly more microleakage compared to the Fuji Plus and Panavia F2.0 groups (P < 0.001) in both closed and open margins. In open margins, differences in microleakage between the Fuji Plus and G-Cem as well as between the G-Cem and Panavia F2.0 groups were significant (P < 0.001). In closed margins, only the G-Cem group displayed significantly more microleakage as compared to the Panavia F2.0 group (P < 0.05). Paired t-test results showed significantly more microleakage in open margins compared to closed margins, except in the Fuji Plus group (P = 0.539).Conclusions:Fuji Plus cement exhibited better sealing ability in closed and open margins compared to G-Cem and Fleck cements. When using G-Cem and Fleck cements for full metal ceramic restorations, clinicians should try to minimize marginal gaps in order to reduce restoration failure. In situations where there are doubts about perfect marginal adaptation, the use of Fuji Plus cement may be helpful.

Microleakage of Different Self-Adhesive Materials for Lithium Disilicate CAD/CAM Crowns

Objectives: To evaluate the microleakage and marginal gap of various luting materials after cementing ceramic crowns. Methods: Cervical margins of human molars were designed as circular chamfers. Cementation of full-contour ceramic crowns was conducted with zinc-phosphate cement (Harvard cement), resin cement (Panavia F 2.0) and self-adhesive resin cements (RelyX Unicem, BifixSE, MaxCem Elite, PermaCem2.0, G-Cem). Aging of specimens was performed in artificial saliva, at 37 °C for four weeks and thermocycling. The marginal gap was measured with a scanning electron microscope and silver precipitation within the microleakage. All data were compared statistically. Results: Independent of the margin preparation, the highest median value for microleakage was 320.2 μm (Harvard cement), and the lowest was 0 μm (Panavia F 2.0). The median value for enamel was 0 µm and for dentin 270.9 μm (p < 0.001), which was independent of the luting material. The marginal and absolute marginal gaps were not significantly different between the tested materials. There was no correlation between microleakage and the marginal gaps. Conclusion: Significant differences in microleakage were found between the tested luting materials (p < 0.05). Independent from the luting materials, the microleakage in dentin showed significantly higher values than in enamel.

Calcium hypochlorite as a dentin deproteinization agent: Microleakage, scanning electron microscopy and elemental analysis.

This study investigated the influence of collagen removal with calcium hypochlorite on the surface morphology of acid-etched dentin and on the microleakage of composite restorations. In addition, the elemental composition (EC) of dentin after removal of the collagen fibrils was analyzed. Forty third molars received two cavities and were divided into four groups according to dentin treatment: CTRL-no pre-treatment; Na10-10% NaOCl for 30 s; Ca10-10% CaOCl for 30 s, and Ca15-15% CaOCl for 30 s. The cavities were filled using an acetone-based adhesive system and a resin composite; they were then subjected to thermal cycling for 5,000 cycles, immersed in methylene blue for 4 h and sectioned into 1-mm thick slabs. Two examiners evaluated two slices per tooth using a stereomicroscope and assigned the degree of infiltration (scores 0-3). The data were analyzed using the Kruskal-Wallis (α = 0.05). Four teeth received surface treatment according to the groups and were submitted to SEM and EDS to carry at the EC. There was no significant difference between the experimental groups (P = 0.533). CaOCl alters the morphology and surface composition of the dentin, resulting in an increase in the amount of calcium in the interface. When used prior to an acetone-based adhesive system, CaOCl did not produce any differences in microleakage when compared to the CTRL group or to the Na10 group.

Evaluation of Pumice, Fissure Enameloplasty, Dentin Adhesive and Air Abrasion on Sealant Microleakage

Aim: To evaluate microleakage of pit and fissure sealant after using four different pit and fissure preparation techniques. o C, for 500 cycles with dwell time of 30 seconds then stored in 0.9% normal saline. All teeth were sealed apically and coated within 1.5 mm of the sealant margin with 2 layers of nail varnish. The teeth were immersed in a 1% solution of methylene blue for 24 hours to allow dye penetration. Three buccolingual cuts parallel to the long axis of the teeth were made yielding 4 sections and 6 surfaces per tooth for analysis. The surfaces were scored 0 to 3 for extent of microleakage using a binocular microscope at 25x magnification. Results: There was no significant difference in microleakage between the four groups although the air abrasion and acid etching exhibited the least microleakage followed by enameloplasty and acid etching then the self etching adhesive system, and the highest microleakage was pumice and acid etching. Conclusions: Neither air abrasion and enameloplasty followed by acid etching nor the self etching adhesive system produced significantly less microleakage than the traditional pumice prophylaxis with acid etching technique.

Microleakage of zirconia frameworks cemented with two types of phosphate monomer-based resin cements

Abstract Objective: Resin cements containing phosphoric acid modified methacrylate monomers are commonly used for zirconia-based restorations. However, there are few studies of microleakage of zirconia frameworks cemented with these types of resin cements. The purpose of this study was to compare microleakage of zirconia frameworks cemented with two types of phosphate monomer-based resin cements after long-term thermocycling. Materials and Methods: Totally, 30 permanent premolars were randomly divided into two groups: Self-etching (SE) (Panavia™ F2.0, Kuraray Medical, Japan) and self-adhesive (SA) (RelyX™ U100, 3M ESPE, USA) resin cements. The teeth were prepared for zirconia frameworks, which were fabricated by TDS CAD/CAM. After cementation and thermocycling (20,000 cycles), specimens were immersed in 2% methylene blue dye solution for 24 h and were sectioned mesiodistally and buccolingually. Microleakage was recorded, and the data were analyzed using the Mann-Whitney U-test and Sign test (α = 0.05). Results: All specimens showed significantly higher microleakage scores at the cementum margins than at the enamel margins (P &lt; 0.05). The SE resin cement provided significantly lower microleakage scores than the SA resin cement at the enamel margin (P &lt; 0.05); however, there were no statistically significant differences in microleakage between two resin cements at the cementum margins (P &gt; 0.05). Conclusion: SE resin cement has a better sealing ability than SA resin cement at the enamel surface. Both resin cements presented high microleakage at the cementum margins, especially at the tooth/resin interface.

Effect of protective coating on marginal integrity of nanohybrid composite during bleaching with carbamide peroxide: A microleakage study.

The aim of the study was to evaluate the microleakage on the marginal integrity of nanohybrid composite during bleaching with carbamide peroxide after applying a protective coating of G-Coat plus (GC, Japan). Class V cavities were prepared and restored with nanohybrid composite restoration in 60 freshly extracted noncarious premolars extracted for orthodontic reasons. Then they were divided into 3 groups. Group 1 - bleaching with carbamide peroxide without G coat plus (n = 20), Group 2 - bleaching with carbamide peroxide with G-Coat plus (n = 20), Group 3 - without bleaching procedure (n = 20) (control group). In Group 2, G coat plus was applied over the restorative surface and margins. Then all teeth in Groups 1 and 2 were taken and mounted in dental stone. Bleaching trays were custom fabricated over the cast with the help of a heated vacuum-forming machine. 10% carbamide peroxide (opalescence PF) was applied over the tooth, and the bleaching process was done for about 2 weeks. Then all samples underwent thermocycling and were then immersed in the 2% methylene blue solution for 24 h and observed under a stereomicroscope to evaluate the amount of dye penetration. Data were compared using Kruskal-Wallis test and Mann-Whitney test using SPSS Inc.; Chicago, IL, USA, Version 17.0. Mann-Whitney test shows that the difference in microleakage between Group 1-Group 2 and Group 2-Group 3 is statistically significant (P < 0.05). Significant reduction in microleakage was seen in Group 2 when compared to other groups.

The effect of various desensitizers on the bond strength of the 4th generation dentin adhesive system

The purpose of this study was to evaluate the effect of shear bond strength and microleakage between dentin and dentin adhesive system after application of dentin desensitizers. Ten desensitizers (UltraEZ, Gluma Desensitizer, MicroPrime G, Systemp desensitizer, SuperSeal, BisBlock, MS-Coat One, Seal&Protect, HurriSeal and Zarosen) were evaluated. Each desensitizer was applied to the dentinal surface and composite resin (Filtek Z-250) was bonded to dentin using dentin adhesive system (Scotchbond MultiPurpose). Then, shear bond strength was measured using an universal testing machine. For microleakage test, class V cavities were prepared and cavities were restored with composite resin using dentin bonding agent after desensitizers application. The data were analyzed using t-test and Newman-Keuls multiple comparisons test (p=0.05). There were no statistical differences in bond strength between the control (24.23 MPa) and the experimental groups treated with HurriSeal (24.99 MPa), Zarosen (24.13 MPa), Gluma Desensitizer (22.44 MPa), MicroPrime G (21.64 MPa), Systemp desensitizer (19.15 MPa), MS-Coat (18.64 MPa), UltraEZ (18.17 MPa). The experimental groups with Seal&Protect (11.71 MPa), SuperSeal (9.12 MPa), BisBlock (8.66 MPa) yielded significantly lower bond strength than the control. There were no statistical differences in microleakage between control group and the experimental groups except for groups treated with SuperSeal and BisBlock.

Effects of Fiber-reinforced Composite Bases on Microleakage of Composite Restorations in Proximal Locations.

Objectives:The aim of this study was to evaluate the microleakage of direct restorative composite resin upon the addition of an intermediate glass fiber-reinforced composite (GFRC) layer of various fiber orientations between tooth and particulate filler composite resin (PFRC). Materials and Methods: Cavities were prepared both on the mesial and distal surfaces of sixty extracted human molars with one margin placed below and the other above the cementoenamel junction (CEJ). Teeth were assigned to five different groups. Four of the groups received a layer of semi-interpenetrating polymer network (semi-IPN) resin system impregnated E-glass GFRC at the bottom of the cavity: Group 1; unidirectional continuous GFRC (EVS) in buccolingual direction (EVS-BL), Group 2; EVS in mesiodistal direction (EVS-MD), Group 3; bidirectional woven GFRC (EVN), Group 4; multidirectional short GFRC (EXP-MLT), Group 5; PRFC only (control). After acid etching and priming of the cavities and insertion of GFRC layer with the adhesive resin (Scotchbond Multipurpose 3M-ESPE), the cavities were filled incrementally with PRFC (Filtek Z250, 3M-ESPE) and each layer was light cured for 20 s. After finishing and polishing, the restored teeth were water-stored for 24 h at 37 °C and then thermocycled for 6000 cycles between 5-55 °C, before immersion in 0.5 % basic fuchsin dye for 24 h. After sectioning by 3-5 sagittal cuts, each sequential section was imaged and digitally analyzed to determine the stain depth. Results: All GFRC groups in dentin revealed significantly lower microleakage compared to control (p<0.05). The orientation of FRC intermediate layer did not reveal significant differences in microleakage (p>0.05). The microleakeage in enamel was not different between the groups (p>0.05).Conclusion: Use of intermediate GFRC layer between tooth and PFRC could provide alternative method to minimize microleakage.Clinical Relevance: Use of GFRC intermediate layer underneath the particulate filler composite can be used to minimize the leakeage of the restorations.

Resistance to leakage of various thicknesses of apical plugs of Bioaggregate using liquid filtration model.

The aim of this study was to compare the resistance to leakage of different thicknesses of Bioaggregate (BA) and 4-mm-thick white mineral trioxide aggregate (WMTA) in an apexification model using liquid filtration. 32 extracted mandibular premolar teeth were sectioned at the cemento-enamel junction and 3-4mm from the tooth apex to obtain 12-mm-long root segments. The apical and coronal thirds were prepared with size two through six Gates Glidden burs. The teeth were divided into four groups according to material and thickness, as follows: Group 1: 2-mm BA; Group 2: 4-mm BA; Group 3: 12-mm (total length) BA; Group 4: 4-mm WMTA (control). The empty parts of the roots in Groups 1, 2, and 4 were filled with gutta-percha and root canal sealer, and leakage was measured using fluid filtration. The data were analyzed using the Kruskal-Wallis H-test. No statistical differences in microleakage were observed between Groups 1, 2, and 4 (P>0.05). Group 3 (roots filled completely with BA) showed significantly less leakage than the other groups tested (P<0.01). The findings of this study showed that 12mm of BA exhibited the best resistance to leakage. At the same time, 2-4mm of BA showed similar results when compared to 4-mm MTA. In light of these results, this study suggests that BA may be a good candidate for further clinical studies when used as an apical barrier for apexification.

Comparison of the Microleakage of Encapsulated and Hand-Mixed Glass Ionomer in Class V Restorations in Deciduous Teeth

Backgrounds: The degree of microleakage is one of the main criteria in evaluating the restorative materials such as glass ionomer (GI) restoratives, which are available in two forms: loose powder and liquid form to be hand-mixed or pre-proportioned in a capsule to be mixed mechanically. Objectives: This study was conducted to compare the microleakage of encapsulated GI restoratives with their hand-mixed equivalent. Materials and Methods: In this interventional (field trial) study, 40 extracted caries-free deciduous teeth were selected. After preparing class V cavities, teeth were divided into two groups. Cavities in group one were restored with encapsulated self-cured GI restorative (EQUIA, Fuji IX). In the second group, hand-mixed GI restoratives (Fuji IX) were used, which were prepared in accordance with the manufacturers’ recommended powder to liquid mixing ratios. After thermo cycling, the samples were immersed in 0.5% methylene blue solution for 12 hours. Then, they were sectioned for examination under light microscope. Micro leakage of each restoration was evaluated by the depth scale of the dye penetration along the tooth-restoration interface. Results: Statistical analysis by Mann-Whitney U test showed no significant difference in micro leakage between encapsulated GI restoratives and their hand-mixed equivalents (P < 0.05). Conclusions: There was no difference between micro leakage of hand-mixed and encapsulated GIs and in case of following the manufacturer’s instruction and recommendations, hand-mixed GIs could be as efficient as their encapsulated equivalents.

Comparison of Micro-Leakage from Resin-Modified Glass Ionomer Restorations in Cavities Prepared by Er:YAG (Erbium-Doped Yttrium Aluminum Garnet) Laser and Conventional Method in Primary Teeth.

In recent years, significant developments have been taking place in caries removal and cavity preparation using laser in dentistry. As laser use is considered for cavity preparation, it is necessary to determine the quality of restoration margins. Glass ionomer cements have great applications for conservative restoration in the pediatric field. The purpose of this in vitro study was to compare resin-modified glass ionomer restorations micro-leakage in cavities prepared by Er:YAG (Erbium-Doped Yttrium Aluminum Garnet) laser irradiation and conventional method in primary teeth. This was an in vitro experimental study. Forty primary canine teeth were divided into 2 groups: group 1 represented cavities prepared by the no. 008 diamond bur, group 2 represented cavities prepared by Er:YAG laser. After cavity preparation, samples were restored by resin-modified glass ionomer. The teeth were thermocycled for 700 cycles, placed in 2% methylene blue for 24h and sectioned in the buccolingual direction. The degree of dye penetration was scored by 3 examiners. Data was analyzed using Mann-Whitney Test. There was no statistical difference in micro-leakage between the two modes of cavity preparation (P=0.862) CONCLUSION: Since preparing conservative cavities is very important in pediatric dentistry, it is possible to use Er:YAG laser because of its novel and portable technology. However, further investigations of other restorative materials and other laser powers are required.

In vitrostudy of microleakage of endodontically treated teeth restored with different adhesive systems and fiber-reinforced posts

Purpose: While studies have examined microleakage in endodontically treated teeth restored with posts, microleakage among post and adhesive systems remains a concern. This study compared the sealing properties of 3 adhesively luted post systems. Materials and methods: Thirty-six endodontically treated permanent maxillary central incisors were divided into 3 groups: Zirconia-glass fiber, Quartz-glass fiber, Polyethylene fiber posts. Post space was prepared and each post was adhesively luted with 3 systems. The specimens were separately immersed in freshly prepared 2% methylene blue solution for 1 week. The cleaned specimens were then embedded in autopolymerizing acrylic resin. The root portion of tooth were horizontally sectioned into three pieces (apical, middle, and coronal portions). An occlusal view of each section was digitally photographed with a stereomicroscope. The methylene blue-infiltrated surface for each specimen was measured. Dye penetration was estimated as the ratio of the methylene blue-infiltrated surface to the total dentin surface. Results: No significant differences were found among post types. The variables of middle section and 3-stage adhesive produced significant differences in microleakage between the following post pairs: zirconia-glass fiber versus quartz-glass fiber, zirconia-glass fiber versus polyethylene fiber, and quartz-glass fiber versus polyethylene fiber (P<.05). There were significant differences between the apical and coronal sections of each post type, and between apical versus middle sections of quarze-glass fiber and polyethylene fiber posts (P<.05). Conclusion: No significant differences were found among post types. The 3-stage adhesive produced significant differences in microleakage between the following post pairs. (J Korean Acad Prosthodont 2014;52:74-81)