Mean Microleakage Score Research Articles

Evaluation of Immediate and Delayed Placement of Post on Sealing ability of Periapical Area: An Original Research

ABSTRACT Objective: The purpose of this research is to compare the effects of post placement—immediate and delayed—on the periapical area’s capacity to close after root canal therapy (RCT). Techniques: A random split of sixty recently removed human single-rooted teeth was made into two groups: Group A received immediate post placement, whereas Group B received post placement after seven days. Standard guidelines were followed in the preparation of root canals and the placement of posts. A dye penetration method was used to measure microleakage, a measure of sealing capacity. Findings: Compared to the immediate post placement group (0.62 ± 0.08) (P < 0.001), the delayed post placement group had a considerably lower mean microleakage score (0.35 ± 0.06), showing improved sealing capacity. In conclusion, post implantation done later enhances the periapical area’s sealing capacity after RCT. This research underscores the significance of scheduling endodontic treatments to maximize treatment success and improve tooth retention, as well as the possible therapeutic advantages of postponing post implantation.

Evaluation of Immediate and Delayed Placement of Post on Sealing Ability of Periapical Area: An Original Research

ABSTRACT Objective: The purpose of this research is to compare the effects of post placement—immediate and delayed—on the periapical area’s capacity to close after root canal therapy. Techniques: A random split of 60 recently removed human single-rooted teeth were made into two groups: Group A received immediate post placement, whereas Group B received post placement after seven days. Standard guidelines were followed in the preparation of root canals and the placement of posts. A dye penetration method was used to measure microleakage, a measure of sealing capacity. Findings: Compared to the immediate post-placement group (0.62 ± 0.08) (P < 0.001), the delayed post-placement group had a considerably lower mean microleakage score (0.35 ± 0.06), showing improved sealing capacity. In conclusion, post implantation done later enhances the periapical area’s sealing capacity after root canal therapy. This research underscores the significance of scheduling endodontic treatments to maximize treatment success and improve tooth retention, as well as the possible therapeutic advantages of postponing post implantation.

In Vitro Evaluation of Sealing Ability of Biodentine and TheraCal PT in Primary Molars.

A major objective in the management of deep carious lesions involving proximal surfaces of primary molars is to control marginal leakage. This could occur due to dimensional changes or failure in the adaptation of pulp capping materials to the prepared cavity. Evaluation of microleakage is important for assessing the success of newer pulp capping materials. Biodentine exhibits good sealing ability but possesses longer setting times and handling difficulties, which might delay the placement of the final restoration. The sealing ability of newer dual-cure calcium silicate-based material in TheraCal PT in class II cavities of primary molars is not known. Hence, the current study aimed to evaluate and compare the microleakage of Biodentine and TheraCal PT in primary molars. Extracted, noncarious primary molars (n = 28) were collected, and standardized class II cavities were prepared and restored with Biodentine (group I) and TheraCal PT (group II). Following this type, IX glass ionomer cement (GIC) was placed and polished. Microleakage was assessed using the dye penetration method, and data obtained through stereomicroscopic analysis were statistically analyzed. The mean microleakage score observed in group I was 2.0 ± 1.3 MPa, and in group II was 1.0 ± 1.1 MPa. Comparable sealing ability was observed between both groups (p = 0.061). TheraCal PT could be used as a suitable alternative to Biodentine for use in vital pulp therapeutic procedures in children to reduce the treatment time and improve sealing ability. Anusha B, Shivashankarappa PG, Mohandoss S, et al. In Vitro Evaluation of Sealing Ability of Biodentine and TheraCal PT in Primary Molars. Int J Clin Pediatr Dent 2024;17(2):158-161.

Comparison of the Effect of Different Bonding Agents on the Microleakage of Two Hydrophilic Pit and Fissure Sealants: An Ex Vivo Study.

To compare the impact of fifth- and seventh-generation bonding agents on the microleakage between Embrace WetBond sealants and Ionoseal. Forty extracted human premolar teeth were used for the study and grouped according to different sealants and bonding agents-group I: Embrace WetBond sealant with fifth-generation bonding agent; group II: Embrace WetBond sealant with seventh-generation bonding agent; group III: Ionoseal with fifth-generation bonding agent; group IV: Ionoseal with seventh-generation bonding agent. For microleakage evaluation, all the teeth were subjected to invasive sealant placement using the respective sealant materials in combination with bonding agents as specified. The treated teeth were stored at 37°C for 24 hours and then thermocycled for 100 cycles at temperatures of 5°C and 55°C with a dwell time of 30 seconds. In order to assess microleakage, the samples were immersed in 0.2% methylene blue dye for 24 hours, then sectioned in buccolingual direction, and evaluated under stereomicroscope. The mean microleakage scores in group III were highest at 0.90 ± 0.57, while the least was in group IV at 0.30 ± 0.68, indicating that Ionoseal with seventh-generation bonding agent was the most effective. However, when the mean microleakage scores of the four groups were compared using Kruskal-Wallis test, it indicated that the differences were not statistically significant. V R, P P, A A, et al. Comparison of the Effect of Different Bonding Agents on the Microleakage of Two Hydrophilic Pit and Fissure Sealants: An Ex Vivo Study. Int J Clin Pediatr Dent 2024;17(3):270-273.

The effect of preprocedural mouthrinses against COVID-19 before acid etching on the microleakage of a resin-based sealant in permanent molars: An in vitro experimental study.

To determine whether rinsing with preprocedural mouthrinses against coronavirus disease before acid etching affects resin-based sealant microleakage. A presented in vitro experimental study was performed on 15 extracted permanent third molars. Samples were randomly allocated into five groups: Group 1-distilled water (control); Group 2-1% hydrogen peroxide; Group 3-1.5% hydrogen peroxide; Group 4-0.5% povidone-iodine; and Group 5-1% povidone-iodine. After the teeth were immersed in the assigned mouth rinses for 60 s, they were sealed with Concise™ white sealant. Subsequently, the teeth were thermocycled for 500 cycles, immersed in 2% methylene blue solution for 24 h, and sectioned with two parallel cuts in the buccolingual direction. Sixty surfaces (12 surfaces in each group) were examined for microleakage under a 40× light microscope and scored as described by Zyskind et al. Welch's one-way analysis of variance test and the Games-Howell test were used to analyze the results at a significance level of P < 0.05 for all tests. The intergroup comparisons indicated that the 0.5% povidone-iodine group and the 1% povidone-iodine group had significantly higher microleakage compared with the control group. The 1% and 1.5% hydrogen peroxide groups demonstrated no significant difference in mean microleakage scores compared with the control group. There was no significant difference between the povidone groups and the hydrogen peroxide groups. Preprocedural rinsing with 0.5% and 1% povidone-iodine before acid etching caused higher microleakage of resin-based sealant, while hydrogen peroxide rinsing gave comparable microleakage compared with the control group.

Comparative Evaluation of Different Post and Core Systems in Maxillary Molar Endodontic Treatments: An Original Study.

Maxillary molar endodontic treatments require the right post and core system. This study tested cast metal, glass fiber with composite resin, carbon fiber with composite resin, and zirconia post and core materials. Sixty removed human maxillary teeth were randomly divided into four post and core material groups (n = 15 per group). The teeth acquired their post and core system after normal endodontic treatment. Fracture resistance, cyclic fatigue resistance, and microleakage analyses were statistically assessed. The zirconia post and core material had the highest fracture resistance (mean: 900 N), followed by carbon fiber with composite resin, cast metal, and glass fiber with composite resin. Zirconia had the highest mean cycles to failure (120,000), followed by carbon fiber with composite resin (100,000), cast metal (110,000), and glass fiber with composite resin (90,000). Zirconia had the lowest mean microleakage score (1.8), and glass fiber with composite resin, the highest (3.0). The zirconia post and core material outperformed the others in fracture resistance, cyclic fatigue resistance, and sealing. The cast metal has better fracture and cycle fatigue resistance than glass fiber with composite resin. These findings help doctors choose maxillary molar endodontic post and core materials.

Microleakage Under Orthodontic Brackets Bonded Using a Conventional Adhesive System, Nanocomposites, and Nanoionomers: A Comparative Study.

Background Microleakage under orthodontic brackets has a role in early bracket debonding and white spot lesions due to the ingress of oral fluids in the bracket-adhesive-tooth interface. This in vitro study aimed to evaluate and compare the microleakage under orthodontic brackets bonded with the conventional adhesive system, nanocomposites, and nanoionomers. Materials and methods Forty-five human premolars were extracted for therapeutic reasons and collected for this study. Teeth were randomly assigned to three groups: Group A: conventional etching with conventional adhesive, Group B: conventional etching with nanocomposite, and Group C: conventional etching with nanoionomer. Stainless steel premolar brackets were used for bonding. After thermocycling, the extracted teeth were submerged in a 0.5% solution of basic fuchsine for 24 hours. They were then cut longitudinally. A stereomicroscope was used to assess microleakage along the occlusal and gingival interfaces. Results To compare the microleakage scores between gingival and occlusal aspects within each group, the student's t-test was performed. Analysis of variance (ANOVA) and the post-hoc Tukey test were applied to the data for intergroup comparison of microleakage scores. On comparing the microleakage scores, the gingival side of interfaces depicted higher microleakage than the occlusal side gingival side across all groups, demonstrating statistically significant results (P <0.05).On intergroup comparison, the occlusal bracket adhesive interface and gingival tooth adhesive interface revealed significantly higher microleakage values for Group B followed by Group C withGroup Athe least. However, there was no significant difference in the microleakage scores between Group B and Group C on intergroup comparison of mean microleakage scores(P <0.05). Conclusion The gingival side showed higher microleakage scores than the occlusal side. Nanoionomers showed microleakage values higher than the Transbond XT but lower than nanocomposites. Based on the results of thepresent study, in terms of microleakage, Transbond XT demonstrated lower microleakage when compared to nanoionomers and nanocomposites.

Microleakage Assessment of Hydrophilic Pit and Fissure Sealants Fortified with Green Synthesized Silver Nanoparticles-An in Vitro Study

Background and Aim: Pit and fissure sealants play a significant role in preventive dentistry. The sealant's physical properties lend a notable contribution to its long-term success. The invention of nanoscience has led to breakthrough discoveries in improving the mechanical properties of sealants. The current work aimed to evaluate the microleakage of Hydrophilic sealant fortified using silver nanoparticles compared to the Hydrophilic sealant and conventional sealant on permanent molars. Materials and methods: Silver nanoparticles were green synthesized using beetroot extract and incorporated into hydrophilic Ultraseal XT Hydro sealant. A sample of extracted third molars, thirty in number, were allocated randomly to three different groups as follows: Group I: conventional Clinpro sealant, Group II: hydrophilic Ultraseal XT hydro, and Group III: Ultraseal XT hydro fortified with silver nanoparticles. Microleakage assessment was performed using a stereomicroscope. The Kruskal-Wallis test was employed to compare the microleakage values of the three groups. Results: Group III had the lowest values about mean microleakage score , and the highest scores were noted for Group I ( . A statistically significant difference was observed in comparing the three groups employing the Kruskal-Wallis test. Conclusion: The results of the current study have established that the microleakage was the lowest in fortified UltraSeal XT Hydro (Group III) when compared to Ultraseal XT Hydro (Group II) and Clinpro sealant (Group I).

In Vitro Evaluation of Viscosity, Depth of Penetration, Microleakage, and Shear Bond Strength of Conventional and Hydrophilic Sealants.

Sealants are effective in preventing and arresting pit and fissure caries. Newer brands of sealants continue to be developed despite the lack of scientifically based information addressing the caries-preventive properties of these materials. Hence, laboratory in vitro tests play a vital role in providing the necessary information regarding the efficacy of new products in a short period of time. To compare and evaluate the viscosity, resin tag length, microleakage, and shear bond strength between conventional and hydrophilic sealants. A total of 40 extracted third molars were selected. Only 20 were evaluated for microleakage and resin tag length and another 20 for shear bond strength evaluation between group I-ClinPro and group II-UltraSeal XT hydro. After sealant placement, specimens were immersed in 0.1% rhodamine dye, followed by thermocycling. Microleakage testing was done using a confocal laser scanning microscope and resin tag length evaluation using a scanning electron microscope (SEM) and shear bond strength using an Universal Instron machine. Viscosity was assessed using an Anton Paar viscometer. Results were subjected to statistical analysis using Statistical Package for the Social Sciences (SPSS) software version 20. Viscosity and mean microleakage scores for group I (0.92 MPa and 1.50) were found to be higher than for group II (0.72 MPa and 0.60). Mean resin tag length and mean shear bond strength for group I (7.46 ± 0.95 μm and 13.71 ± 0.94 MPa) were found to be less compared to group II (10.03 ± 1.00 μm and 20.39 ± 0.98 MPa). The results were found to be statistically significant (p < 0.05). Group II was found to be less viscous, which resulted in the formation of resin tags of sufficient length and showed less microleakage and higher shear bond strength than group I. Prabakar J, Jeevanandan G, Kengadaran S. In Vitro Evaluation of Viscosity, Depth of Penetration, Microleakage, and Shear Bond Strength of Conventional and Hydrophilic Sealants. Int J Clin Pediatr Dent 2023;16(5):745-750.

Comparison of Different Dentin Deproteinizing Agents on Bond Strength and Microleakage of Universal Adhesive to Dentin

Aim: To evaluate the effects of papain (Brix 3000), bromelain, sodium hypochlorite (NaOCl), and chlorine dioxide (ClO2) application to the deep dentin surface on shear bond strength (SBS), microleakage, and dentin surface properties. Materials and Methods: Deep dentin surface ( n = 100) for evaluating SBS, class V preparation at the buccal surface for testing microleakage ( n = 100), and deep dentin slices ( n = 20) for evaluating surface properties were conducted on the 220 molar teeth. Four different deproteinizing agents (Brix 3000, 40% bromelain, 5.25% NaOCl (Chloraxid), and 0.12% ClO2) were applied to the dentin, and then the universal adhesive was used in self-etch (SE) and etch&amp;rinse (E&amp;R). Deproteinizing agents were not applied to the control group. All of the samples were subjected to 5000 cycles of thermal aging at 5ºC–55ºC. SBS (MPa) was tested by a universal testing machine. The microleakage of resin composite bonded with different adhesive modes was evaluated under a stereomicroscope. The changes in the surface morphology were examined with scanning electron microscopy (SEM) and attenuated total reflection – fourier transform infrared spectroscopy (ATR-FTIR). Results: ClO2 exhibited the highest bond strength among deproteinizing agents. Compared to the SE mode, E&amp;R mode significantly showed higher bond strength ( p &lt; .05). In gingival margin, bromelain SE exhibited the highest marginal leakage, while Brix 3000 SE had the lowest mean microleakage score. Conclusion: Deproteinizing with ClO2 was effective in improving the SBS of universal adhesive in the E&amp;R mode to deep dentin. Deproteinization with bromelain before universal adhesive in SE mode showed more microleakage on both the occlusal and gingival surfaces.

Potential of chitosan oligosaccharide gel as a cavity cleanser against adhesive restoration adhesive on the cavity wall

Cavity cleanser is a cavity cleaner with ideal properties such as being biocompatible, antibacterial,removing smear layers, and not interfering with the adhesive bond. This study aims to examine the potential of gelchitosan oligosaccharide (COS) as a cavity cleanser on the adhesion of the restoration to the cavity wall. Thirty-twomandibular premolars with class V restorations are divided into two groups with 2% COS gel and 2% chlorhexidinedigluconate (CHX). Samples were immersed in 2% methylene blue, cut longitudinally, observed under astereomicroscope with 1x magnification, and scored 0-3. The Mann-Whitney test was used to see the potential of gelCOS as a cavity cleanser. The results showed a significant difference between the two groups at the edge of theenamel junction restoration (p=0.038) and the dentin junction restoration (p=0.027). The mean microleakage score ingroup 1 showed better results at the enamel junction (1.19± 1.328) and the dentin junction (2.00±1.211). It shows that2% COS gel has the potential as a cavity cleanser. There was a significant difference between the two groups as acavity cleanser on the adhesion of adhesive restorations to the cavity wall.KEYWORDS: cavity cleanser; chitosan oligosaccharide; chlorhexidine digluconate; microleakage

Comparative evaluation of microleakage and hardness of newer posterior restorative materials.

The physical properties of restorative materials are critical when restoring posterior teeth. Restorative materials are continuously evolving in the quest for creating long lasting restorations. To compare and evaluate microleakage and hardness of three different posterior restorative materials: Cention N, Zirconomer Improved and Solare Sculpt. For micro leakage evaluation, 40 extracted human third molars were randomly divided into three experimental groups of 10 teeth each and two control group of 5 teeth each. Standardized box shaped class II cavity preparation was done in Group I, II, III and V. In Group V, cavity was prepared but left unrestored. No cavities were prepared in Group IV. Cavities in Group I, II, and III were restored with Cention N, Zirconomer Improved, Solare Sculpt respectively. Teeth were thermocycled together for 500 cycles. All the samples were placed in 2% methylene blue for 24h. Microleakage evaluation was done using stereomicroscope. For hardness evaluation ten standardized discs of each material were prepared and evaluated using vicker's hardness test. All the groups showed some amount of microleakage. The mean micro-leakage score was significantly more among Group II compared to Group I. There was no significant difference in mean micro-leakage score between Groups I and III. The mean hardness value was significantly more among Groups I and II compared to Group III. No material was able to completely eliminate microleakage. Cention N showed high hardness among the materials tested.

Microleakage beneath orthodontic brackets in high field magnetic resonance imaging (MRI) AT 1.5 & 3 Tesla.

The aim of the present study was to evaluate the effects of 1.5 T and 3 T MRI on the adhesion between the orthodontic brackets and the teeth by evaluating the microleakage between the enamel, adhesive and brackets interfaces. 58 extracted human premolars which were received a standard bracket bonding procedure were randomly divided into three groups; control group (n = 20; no MRI), 1.5 T MRI group (n = 19; 20 min MRI exposure of 1.5 T) and 3 T MRI group (n = 19; 20 min MRI exposure of 3 T). The teeth were kept in distiled water for 2 weeks, and thereafter subjected to 500 thermal cycles. Then, specimens were sealed with nail varnish, stained with 0.5% basic fuchsin for 24 h, sectioned and photographed under a stereomicroscope. Microleakage was scored with regard to the adhesive-enamel and bracket-adhesive interfaces at the occlusal and gingival levels. Statistical analysis was accomplished by Kruskal-Wallis and Bonferroni-Dunn tests. All of the groups exhibited statistically similar microleakage scores in the adhesive-enamel interface along occlusal margins (p>0.05, p = 0.331). The mean microleakage scores along gingival margins in the 3 T MRI group was significantly higher compared to the control group both in the adhesive-enamel and bracket-adhesive interfaces (p<0.05, p = 0.019 and p = 0.020 respectively). The microleakage scores along the gingival margins were also significantly higher than the occlusal margins in the 3 T MRI group (p<0.05, p = 0.029). 3 T MRI may weaken the adhesion between the enamel and the stainless steel orthodontic brackets.

Marginal microleakage and modified microtensile bond strength of Activa Bioactive, in comparison with conventional restorative materials.

This study aimed to assess the enamel and dentin marginal microleakage and dentin microtensile bond strength (μTBS) of ACTIVA BioACTIVE Restorative with and without a bonding agent compared with conventional restorative materials. For enamel and dentin microleakage, Class II boxes were prepared in the mesial (1 mm under the cementoenamel junction) and distal (1 mm above the cementoenamel junction) surfaces of 90 extracted human third molars. The teeth were randomly divided into five groups (n = 18): Group Z (G-Premio Bond + Filtek Z250 XT), Group X (G-Premio Bond + X-tra fil bulk-fill), Group AA (G-Premio Bond + Activa Bioactive restorative), Group A (Activa Bioactive restorative), and Group G (dentin conditioner + Fuji II LC Improve). The teeth were thermocycled, and their microleakage was quantified using the dye penetration test under a stereomicroscope. For dentin μTBS measurement, 12 specimens were fabricated in metal molds (1 × 1 × 12 mm³) for each group mentioned above, and a universal testing machine measured their μTBS. Data were analyzed using one-way analysis of variance (ANOVA), the Kruskal-Wallis test, and multiple comparisons tests. Significant differences were noted among the groups in marginal microleakage and μTBS (p < .001). The highest mean microleakage scores at the enamel and dentin margins were noted in Group A, which had significant differences with other groups (p < .001). The highest μTBS was found in Group X, with significant differences with Group G and Group A (p < .05). The lowest µTBS was noted in Group A, with significant differences with Groups X, Group AA, and Group Z (p < .001). Activa Bioactive without a bonding agent showed significantly lower µTBS to dentin, and higher microleakage at the enamel and dentin margins. Application of adhesive resin with Activa Bioactive provided a dentine bond strength and marginal seal comparable to other restorative materials.

Evaluation of Microleakage of Micro Hybrid Composite Resins versus Chitosan-Incorporated Composite Resins When Restored in Class V Cavities Using Total Etch and Self-Etch Adhesives: An In vitro Study.

Aim:To evaluate the in-vitro microleakage of traditional micro hybrid composite resin and 0.2% chitosan-incorporated composite resin when restored in Class V cavities using total etch versus self-etch adhesives after storing in artificial saliva for 24 h.Materials and Methodology:Sixty permanent maxillary premolars collected and Class V cavities were prepared on buccal surface of each tooth (dimensions: mesio-distally 3 mm, occluso cervically 2 mm, and depth of 1.5 mm) and restored with Group 1: micro hybrid (30 teeth) and Group 2: chitosan-incorporated composite (30 teeth), which was further subdivided into: (a) 15 teeth using total-etch adhesives. (b) 15 teeth using self-etch adhesives. Next dye extraction test was carried out using spectrophotometer.Results:Comparison within groups: In Group 1: Self-etch demonstrated less microleakage (0.0129) compared with total etch (0.0183). The difference was statistically significant, and in Group 2: No statistically significant difference was found in mean microleakage scores after using either self-etch (0.0118) or total etch adhesives (0.0120).Conclusion:It can be concluded that chitosan-incorporated composite seems to have improved mechanical properties with a stable bond when used with either self-etch or total etch adhesives in addition to being antibacterial. It may be clinically useful in restoring Class V cavities in patients with high caries risk. However, further in vitro and in-vivo studies need to be carried out.

Effects of different antibacterial disinfectants on microleakage of bulk-fill composite bonded to different tooth structures

BackgroundThis in-vitro study aimed to investigate the effect of two different antibacterial disinfectants on the microleakage performance of newly developed bulk-fill composite, bonded to different tooth structures.MethodsClass V cavities were prepared in 30 sound premolar teeth, with enamel occlusal margins (OM) and dentin cervical margins (CM). Two disinfectants, 2% chlorhexidine gluconate (CHX) and Listerine Miswak (ListM), were used. Teeth were divided into three groups (n = 10): G1, Control; G2, CHX; and G3, ListM. Disinfectants were applied to the cavity preparation walls after they were etched with 35% phosphoric acid. The Single Bond Universal adhesive system was then used, and teeth were restored with Filtek One Bulk Fill composite. Samples were examined, after thermocycling aging, by stereomicroscopy for the evaluation of marginal dye penetration.ResultsThe highest mean microleakage score was reported in the CM of G1 (2.60 ± 1.174), which was significant compared with that of G2 only (p = 0.02). OM in G1 showed no microleakage, with no significant differences found among groups (χ2 = 1.39, p = 0.50). No significant differences were reported between G2 and G3 (p = 0.45 OM; p = 0.17 CM).ConclusionsCavity pretreatment with CHX is not significantly different to pretreatment with CHX. In contrast, CHX improved the cervical marginal seal as compare to the control group (G1).

Assessment of internal fit and micro leakage of conventionally fabricated ceramometallic restoration versus CAD wax and press veneering (in-vitro study)

Statement of problemAccuracy of internal fit and microleakage for CAD-CAM systems used in metal coping fabrication and veneered with layering or pressing porcelain in ceramometallic restoration is unclear.Material and methodsA master metal die was milled to resemble the right mandibular first molar preparation for coverage with ceramometallic restoration. Master die was duplicated to twenty-four resin specimen dies.They were divided into two groups according to metal coping construction technique using either conventional (C) or CAD (D) wax. Each group was subdivided into two subgroups (n = 6) according to the technique of porcelain veneering (layered or pressed) to fabricate ceramometallic restorations, where subgroup (CL, DL) were conventionally layered by porcelain and (CP, DP) were press veneered. A standardized thickness of metal and porcelain was performed in all specimens as per manufacturer’s instructions for techniques ceramometallic restoration construction.Evaluation of internal fit was done with silicone replica technique using stereomicroscope at ×24 magnification where the thickness of silicon layer was measured at 20 reference points on each specimen. Then specimens were subjected to thermocycling. Sectioned specimens were assessed for microleakage using a stereomicroscope at ×12 magnification along die-cement interface with a five scale score.ResultsMean internal gap values of veneering showed a statistically nonsignificant difference between specimens made with layering(L) and pressing(P). Different techniques of wax construction showed a non-significant difference in internal gap values between specimens made with conventional(C) and CAD(D) waxing. However, a significant difference was found in the internal gap at different sites. The highest internal gap was found at the occlusal surface, while the lowest gap was found at the finish line. The highest mean microleakage score was found with CAD wax and press veneering, while the lowest mean microleakage score was found with conventional wax and press veneering.ConclusionBoth construction techniques of ceramometallic restoration were considered reliable in restoration production within a clinically acceptable range regarding internal fit and microleakage. There is a strong positive correlation between internal fit and microleakage of ceramometallic restoration constructed.

Stereomicroscopic Analysis of Microleakage, Evaluation of Shear Bond Strengths and Adhesive Remnants Beneath Orthodontic Brackets under Cyclic Exposure to Commonly Consumed Commercial “Soft” Drinks

Objective: This study aimed to evaluate the effects of Coca-Cola®, Sprite®, and Maaza® on Microleakage, shear bond strength (SBS) and adhesive remnants underneath orthodontic brackets. Materials and Methods: A total of 192 human premolar teeth were used in this study. The sample was divided into four groups: Artificial saliva (control) [Group 1], Coca-Cola [Group 2], Sprite [Group 3] and Maaza [Group 4]. All the samples were stored in artificial saliva and immersed in their respective testing media (except the control group) for 15 minutes 3 times a day, separated by intervals of 8 hours. The immersion cycle was repeated for 15 days. After the immersion cycle, 24 teeth from each group were tested for SBS and adhesive remnant index subsequently. The remaining 24 teeth from each group underwent dyeing with methylene blue and were analyzed stereomicroscopically to evaluate microleakage underneath the brackets. Kolmogorov-Smirnov and Shapiro normality tests were performed and homogeneity of variance was tested with the Levene test. One-way ANOVA and Kruskal-Wallis tests were carried out separately for SBS, ARI and microleakage. Statistical analyses were performed using SPSS 20 for Windows (SPSS Inc., Chicago) software. Results: Coca-Cola showed a significant reduction in SBS and microleakage (p &lt; 0.05) compared to the other groups. ARI did not show any significant differences between any groups (p &gt; 0.05). The mean microleakage scores were higher for the gingival side of the brackets compared to the incisal side. Both Sprite and Maaza showed significant differences compared to artificial saliva, despite the SBS not being statistically significant (p &gt; 0.05). Conclusions: A significant reduction of SBS was observed in Coca-Cola while increased microleakage was seen in all three drinks compared to artificial saliva.

Microleakage at Implant Abutment and Prosthesis Interface in Cemented Implant-Supported Prosthesis.

Background:Dental implants have an important role in mainstream dental practice today to restore esthetics. The present study was conducted to evaluate the microleakage at implant abutment and prosthesis interface in cemented implant-supported prosthesis.Materials and Methods:The present study comprised sixty replicas of abutment analog with length 5 mm, width of platform 4.8 mm, and taper 6° which were milled and divided into three groups. In Group I, nickel–chromium copings were fabricated; marginal gap was evaluated with optical microscope and luted with zinc oxide noneugenol cement, Group II with zinc polycarboxylate cement, and Group III with zinc phosphate cement. Microleakage was scored by the method used by Tjan et al.Results:The mean microleakage score in Group I was 2.5, in Group II was 1.9, and in Group III was 1.05. The difference was significant (P < 0.05).Conclusion:All cements showed microleakage. Minimum microleakage was seen with zinc phosphate cement than zinc oxide noneugenol cement and zinc polycarboxylate cement.

Comparative evaluation of microleakage of metallic copings luted with three different commercially available luting cements: An in vitro study.

Aim:To evaluate the microleakage of metallic copings luted with three different commercially available luting cements.Setting and Design:Comparative evaluation in vitro study.Materials and Methods:Thirty replicas of abutment analog were milled and divided into 3 groups. Nickel chromium copings were fabricated; marginal gap was evaluated with optical microscope and luted with Zinc Oxide Non Eugenol cement, Zinc Polycarboxylate cement and Zinc Phosphate cement. After Thermocycling, cemented specimens were placed into 0.5% aqueous solution of basic fuchsin solution for 24 hours for dye penetration. Copings were longitudinally sectioned and microleakage scores were evaluated.Statistical Analysis Used:Kruskal-Wallis analysis of variance (ANOVA) followed by Chi-Square test. Pairwise comparison of groups with Mann Whitney U test.Result:Mean microleakage score was least for Zinc Phosphate cement (1.075 ± 0.85) followed by Zinc Polycarboxylate cement (1.80± 0.23) and most for Zinc Oxide Non Eugenol (2.1± 0.37). The results of the study were statistically significant, P < 0.05.Conclusions:Within the limitations of the study, it was found that all cements exhibited certain amount of microleakage. Zinc Phosphate cement exhibited a mean microleakage score that was significantly lower than Zinc Oxide Non Eugenol cement and Zinc Polycarboxylate cement. When microleakage scores of Zinc Oxide Non Eugenol cement and Zinc Polycarboxylate cement were compared, the difference was found to be insignificant indicating that microleakage in these cements is similar.