Impact of acid and laser etching of enamel on microleakage in different adhesive systems.

This study aimed to evaluate the microleakage of light-cured and self-cured adhesives on enamel surfaces selectively etched with Er, Cr: YSGG laser or 35% phosphoric acid. A total of 60 class V cavities were prepared 1 mm above the cemento-enamel junction (CEJ). The specimens were randomly divided into six groups. Group 1: Clearfil SE Bond with no conditioning, Group 2: Tokuyama Universal Bond with no conditioning, Group 3: Clearfil SE Bond conditioned with 35% phosphoric acid, Group 4: Tokuyama Universal Bond conditioned with 35% phosphoric acid, Group 5: Clearfil SE Bond conditioned with Er, Cr: YSGG laser and Group 6: Tokuyama Universal Bond conditioned with Er, Cr: YSGG laser. Microleakage was evaluated qualitatively (visually) and quantitatively (ImageJ). The data were analyzed using IBM SPSS V23 and submitted to Kruskal-Wallis and Wilcoxon tests. The significance level was set at p < 0.05. In all evaluation methods, the microleakage scores exhibit significant differences (p*<0.001). Group 1 and Group 3 exhibited similar and lower microleakage values than the Group 5. In the occlusal margin, the microleakage values were similar in Group 2, Group 4, and Group 6, whereas in the gingival margin Group 4 showed significantly lower leakage compared to Group 2. Regardless of the etching protocols and adhesive systems used, less microleakage was observed on the occlusal surface than on the gingival surface. Phosphoric acid etching provides better results than laser etching for enamel surface treatment on both occlusal and gingival surfaces.

Comparison of the sealing ability amongst orthograde apical plugs of mineral trioxide aggregate plus, mineral trioxide aggregate repair HP, and Biodentine after root resection: a bacterial leakage study.

This study aimed to analyse the effect of root-end resection on the sealing ability of orthograde apical plugs of three root-end filling materials (MTA Repair HP, Biodentine, MTA Plus) using the bacterial leakage method and compare it with the retrograde root-end filling technique. Eighty-four extracted mandibular premolar teeth with single root and single straight canals were selected and randomly divided into two main experimental groups (n = 36) depending on the apical plug placement technique and a control: Group I: orthograde technique, followed by root-end resection; Group II: retrograde root-end filling technique; one control Group III (n = 12): obturation with gutta-percha, followed by root-end resection. Experimental groups were further subdivided into three subgroups A, B, and C (n = 12) depending on the three different root-end filling materials used. An apical plug of 3 mm thickness was obtained in both the experimental groups. The apical sealing ability was evaluated with the dual-chamber bacterial leakage method. Statistical analysis was performed using the Kaplan-Meier survival analysis test. By the end of 30 days, the occurrence of turbidity indicating bacterial leakage was 75% in MTA Repair HP, 83.3% in Biodentine, and 91.7% in MTA Plus samples. This trend of turbidity was similar in both orthograde and retrograde technique. The control group showed turbidity in all the samples (100%). More MTA Repair HP samples (25%) survived the 30 days observation period with no bacterial leakage compared to Biodentine (16.7%) and MTA Plus (8.3%). The sealing ability of already set root-end filling materials placed through the orthograde technique did not deteriorate after root-end resection. Also among three root-end filling materials, MTA Repair HP presented the lowest bacterial microleakage followed by Biodentine and MTA Plus, respectively.

Evaluation of microleakage of mineral trioxide aggregate and biodentine as apical barriers in simulated young permanent teeth.

BACKGROUND: Apexification is a procedure that promotes apical closure by forming mineralized tissue in the apex region of a nonvital young permanent tooth. Calcium silicate-based cement like Mineral trioxide aggregate (MTA) and Biodentine are commonly employed as apical barriers to facilitate this process. Microleakage, defined as the leakage along the junction between the canal wall and filling material, is a crucial aspect to assess in MTA and Biodentine applications as apical barriers, as it directly impacts the prevention of bacterial seepage and maintenance of structural integrity. The current study aims to assess the microleakage of MTA and Biodentine when used as apical barriers in simulated young permanent teeth. METHODS: From a total of 128 extracted teeth, 114 were selected for the study and randomly allocated into three groups: G1 (MTA), G2 (Biodentine), and G3 (Control), with 38 teeth per group. After excluding 5 teeth from each group due to issues such as canal calcification, breakage during sectioning, and procedural errors, 33 teeth were analyzed to ensure equal distribution. To simulate young permanent teeth, samples were instrumented using a person-reamer with a diameter of 1.7 mm. A 4 mm thick apical plug of MTA and Biodentine was placed in G1 and G2, respectively, while G3 was the control group. Apical microleakage in all experimental groups was assessed using a dye penetration method. Specimens were longitudinally sectioned and examined under a stereomicroscope with graded eyepiece. RESULTS: The Kruskal-Wallis test revealed variations in mean apical microleakage among the groups: G1 recorded 0.67, G2-0.16, and G3-1.62, with G2 showing the lowest value and G3 group exhibiting the highest. CONCLUSIONS: Biodentine was found to excel in its ability to create a secure seal and function effectively as an apical barrier in simulated young permanent teeth. These results underscore its potential as a highly efficient material for dental applications, particularly in scenarios requiring reliable sealing and barrier formation in the root canal system of developing permanent teeth.

Evaluating flexure properties, hardness, roughness and microleakage of high-strength injectable dental composite: an in vitro study.

BACKGROUND: Recently, a new generation of high-strength flowable dental composites has been introduced by manufacturers. The manufacturers claim that these materials have enhanced mechanical and physical properties and are suitable for use in a wide range of direct anterior and posterior restorations, even in high-stress bearing areas. AIM: The objective of this study was to assess certain physical and mechanical properties of these recently introduced high-strength flowable composites in comparison to conventional multipurpose dental composites. METHODS: Four types of high-strength flowable composites (Genial Universal FLO, Gaenial Universal Injectable, Beautifil Injectable, and Beautifil Flow Plus) were tested in experimental groups, while a nanohybrid conventional composite (Filtek Z350 XT) was used as the control. For flexure properties, ten rectangular samples (2 × 2 × 25 mm) were prepared from each composite material and subjected to 5000 cycles of thermocycling. Samples were then subjected to flexural strength testing using the universal testing machine. Another twenty disc-shaped specimens of dimensions (5 mm diameter × 2 mm thickness) were fabricated from each composite material for surface roughness (Ra) (n = 10) and hardness (VHN) test (n = 10). All samples underwent 5000 cycles of thermocycling before testing. Additionally, microleakage testing was conducted on 60 standardized class V cavities prepared on molar teeth and divided randomly into five groups (n = 12). Cavities were then filled with composite according to the manufacturer's instructions and subjected to thermocycling for 1000 cycles before testing using methylene blue solution and a stereomicroscope. RESULTS: All tested materials were comparable to the control group in terms of flexural strength and surface roughness (p > 0.05), with Gaenial Universal FLO exhibiting significantly higher flexural strength compared to the other flowable composite materials tested. However, all tested materials demonstrated significantly lower elastic modulus and surface hardness than the control group (p < 0.05). The control group exhibited higher microleakage scores, while the lowest scores were observed in the Gaenial Universal FLO material (p < 0.05) CONCLUSION: The physical and mechanical behaviors of the different high-strength flowable composites investigated in this study varied. Some of these materials may serve as suitable alternatives to conventional composites in specific applications, emphasizing the importance of dentists being familiar with material properties before making material selections.

Influence of curing mode and aging on the bonding performance of universal adhesives in coronal and root dentin.

BACKGROUND: This study aims to evaluate the microtensile bond strength (µTBS) of different resin composite restorations bonded to mid-coronal dentin and proximal root dentin using light-cured, chemical-cured, and dual-cured adhesives immediately and after aging. Nanoleakage and degree of cure were also assessed. METHODS: Eighty-four molars were divided into mid-coronal dentin and proximal root dentin. Each group was further subdivided into three subgroups based on the restorative systems used, which involved the utilization of light-cured, chemical-cured, and dual-cured adhesives. Half of the specimens underwent µTBS testing after 24 h, while the other half after aging. Representative specimens were analyzed for nanoleakage. The degree of cure of the tested adhesive systems was also assessed. RESULTS: Aging showed a significant negative effect on µTBS results and led to increased nanoleakage (p < 0.001). Furthermore, in all subgroups, the µTBS values of proximal root dentin were lower compared to mid-coronal dentin, except in the aged subgroup for the system utilizing the dual-cured adhesive. The restorative systems with chemical and dual-cured adhesives demonstrated comparable bonding properties. However, the system with the light-cured adhesive exhibited the worst bonding properties after aging when bonded to proximal root dentin and cured at a large distance (p < 0.05). CONCLUSIONS: All tested restorative systems were negatively affected by aging, and the regional dentin had variable effects on the bonding properties. Clinicians should exercise caution when using the tested light-cured adhesive in areas where the curing distance exceeds 3 mm.

Effect of Salvadora persica on resin-dentin bond stability.

BACKGROUND: The stability of resin-dentin interfaces is still highly questionable. The aim of this study was to evaluate the effect of Salvadora persica on resin-dentin bond durability. MATERIALS AND METHODS: Extracted human third molars were used to provide mid-coronal dentin, which was treated with 20% Salvadora persica extract for 1 min after acid-etching. Microtensile bond strength and interfacial nanoleakage were evaluated after 24 h and 6 months. A three-point flexure test was used to measure the stiffness of completely demineralized dentin sticks before and after treatment with Salvadora persica extract. The hydroxyproline release test was also used to measure collagen degradation by endogenous dentin proteases. Statistical analysis was performed using two-way ANOVA followed by post hoc Bonferroni test and unpaired t-test. P-values < 0.05 were considered statistically significant. RESULTS: The use of Salvadora persica as an additional primer with etch-and-rinse adhesive did not affect the immediate bond strengths and nanoleakage (p > 0.05). After 6 months, the bond strength of the control group decreased (p = 0.007), and nanoleakage increased (p = 0.006), while Salvadora persica group showed no significant difference in bond strength and nanoleakage compared to their 24 h groups (p > 0.05). Salvadora persica increased dentin stiffness and decreased collagen degradation (p < 0.001) compared to their controls. CONCLUSION: Salvadora persica extract pretreatment of acid-etched dentin preserved resin-dentin bonded interface for 6 months. CLINICAL SIGNIFICANCE: Durability of resin-dentin bonded interfaces is still highly questionable. Endogenous dentinal matrix metalloproteinases play an important role in degradation of dentinal collagen within such interfaces. Salvadora persica may preserve resin-dentin interfaces for longer periods of time contributing to greater clinical success and longevity of resin composite restorations.

Bacterial sealing ability of calcium silicate-based sealer for endodontic surgery: an in-vitro study.

BACKGROUND: Apical surgery with standard retrograde maneuvers may be challenging in certain cases. Simplifying apical surgery to reduce operating time and streamline retrograde manipulation is an emerging need in clinical endodontics. AIM OF THE STUDY: The aim of the study was to compare the bacterial sealing ability of a calcium silicate-based sealer with the single cone technique combined with root end resection only, and calcium silicate-based sealer as a retrograde filling versus MTA retrofilling, and to analyze bacterial viability using confocal laser scanning microscope (CLSM). MATERIALS AND METHODS: In this in vitro experimental study, 50 extracted human maxillary incisor teeth were instrumented and randomly divided into five groups: three experimental groups, a positive control group, and a negative control group (n = 10/group). In the experimental groups, the roots were obturated using the single cone technique (SCT) and a calcium silicate-based sealer. In group 1, the roots were resected 3 mm from the apex with no further retrograde preparation or filling. In groups 2 and 3, the roots were resected, retroprepared, and retrofilled with either a calcium silicate-based sealer or MTA, respectively. Group 4 (positive control) was filled with a single gutta-percha cone without any sealer. In group 5 (negative control), the canals were left empty, and the roots were sealed with wax and nail varnish. A bacterial leakage model using Enterococcus faecalis was employed to assess the sealing ability over a 30-day period, checking for turbidity and analyzing colony forming units (CFUs) per milliliter. Five specimens from each group were examined using CLSM for bacterial viability. Data for the bacterial sealing ability were statistically analyzed using chi-squared and Kruskal-Wallis tests. RESULTS: The three experimental groups did not show significant differences in terms of bacterial leakage, or bacterial counts (CFUs) (P > 0.05). However, significant differences were observed when comparing the experimental groups to the positive control group. Notably, the calcium silicate-based sealer, when used as a retrofilling, yielded the best sealing ability. CLSM imaging revealed viable bacterial penetration in all the positive control group specimens while for the experimental groups, dead bacteria was the prominent feature seen. CONCLUSION: Within the limitations of this study, it could be concluded that the bacterial sealing ability of calcium silicate-based sealer with the single cone technique combined with root end resection only and calcium silicate-based sealer as a retrograde filling were comparable with MTA retrofilling during endodontic surgical procedures.

Effect of cervical margin relocation on marginal adaptation and microleakage of indirect ceramic restorations.

PURPOSE: This study evaluated the effect of cervical margin relocation (CMR) with two different materials and contamination with hemostatic agents on the margin adaptation and microleakage of ceramic restorations. MATERIALS AND METHODS: Mesial-occlusal-distal cavities were prepared in 60 human first molars and distributed to 3 groups (n = 20) according to the margin relocation procedure. The groups were: group F; flowable composite applied in two 2 mm increments, group B; bulk-fill flowable composite applied as a bulk increment of 4 mm thickness and group C (control); no CMR was done. Each group was subdivided into two subgroups (subgroup N; no hemostatic agent applied and subgroup H; hemostatic agent was applied). In all groups, ceramic inlays were prepared and cemented. The samples were subjected to thermocycling (10,000 cycles). The adaptation of the cervical margin was evaluated with scanning electron microscopy (200×). Samples were then assessed for microleakage analysis with the dye penetration method. Marginal adaptation data were normally distributed and analyzed using two-way ANOVA followed by Tukey's post hoc test. Ordinal microleakage score data were analyzed using cumulative link models followed by the analysis of deviance using Wald chi-square tests. RESULTS: Both CMR and contamination with a hemostatic agent had significant effects on the margin adaptation of the cervical margin. Group C showed the highest adaptation with no significant difference from group F. The lowest adaptation was revealed in group B with a significant difference from group C. Subgroup N (in all groups) showed a statistically higher adaptation than subgroup H. Regarding microleakage assessment, CMR had no significant effect but hemostatic agent application showed a significantly higher microleakage score for all groups. CONCLUSIONS: Both the CMR procedure and contamination with AlCl3 hemostatic agent had a negative effect on marginal adaptation. For microleakage assessment, only contamination with hemostatic agent negatively affected the microleakage with no effect on the margin relocation procedure.

In Vitro Microleakage and Fracture Resistance of "Infinity Edge" and Cusp Reduction Preparation Designs for Moderate-sized Class II Composites.

AIM: This study aimed to evaluate the marginal microleakage and maximum occlusal fracture loads and fracture modes of two novel class II preparation designs, "infinity edge" and the "2.5 mm cusp reduction" preparations as compared to a traditional class II preparation without cuspal involvement. MATERIALS AND METHODS: Thirty extracted human mandibular molars were prepared for moderate-sized class II restorations with extensions into all occlusal grooves. Of these, ten class II preparations served as control. Ten were modified for a 2.5 mm even reduction of the cusps adjacent to the interproximal box. An additional 10 preparations were modified with an "infinity edge" bevel on the interproximal and occlusal portions. All teeth were restored utilizing a flowable bulk-fill composite in the apical portion of the interproximal box and 2-4 mm of heated bulk-fill composite in one increment for the remainder. All groups were cyclic loaded and thermocycled, then imaged with microcomputed tomography (µCT) before and after infiltration with a silver nitrate solution. Images were subtracted to obtain volumetric measurements of microleakage and reported as a percentage of the total volume from the apical extent of the proximal box. All groups were loaded to failure and fracture load and mode were recorded. RESULTS: No significant differences were found in microleakage volume as a percentage of total tooth volume; however, the "infinity edge" group had significantly greater microleakage in the proximal box compared to the traditional class II group. No significant differences were found in fracture load or mode between the groups. CONCLUSION: Traditional class II, 2.5 mm cuspal reduction, and "infinity edge" preparation designs have similar fracture loads as well as volumes of microleakage; however, an "infinity edge" preparation has a higher ratio of microleakage in the proximal box. CLINICAL SIGNIFICANCE: Clinicians should carefully consider the use of "infinity edge" margins, particularly on dentin in the apical extent of the proximal box. How to cite this article: Watson JC, Lien W, Raimondi JC, et al. In Vitro Microleakage and Fracture Resistance of "Infinity Edge" and Cusp Reduction Preparation Designs for Moderate-sized Class II Composites. J Contemp Dent Pract 2024;25(1):3-9.

Comparative Assessment of Marginal Micro Leakage of Different Esthetic Restorative Materials Used on Primary Teeth: An In-vitro Study.

AIM: The aim of the current investigation was to evaluate the marginal microleakage of various esthetic restorative materials applied to primary teeth. MATERIALS AND METHODS: A total of 75 noncarious primary molars that were removed for orthodontic intervention and teeth nearing exfoliation were chosen. One millimeter (mm) above the cementoenamel junction, on the buccal surface of the teeth, Class V cavities were prepared. William's graded periodontal probe was used to standardize cavity preparation on all teeth. 3 mm was the cavity's length, 2 mm in width, and 2 mm in depth. The teeth were then divided into three groups (25 samples in each group) according to the type of esthetic restorative material used. Group I: Resin-modified glass ionomer cement, Group II: Ormocer, Group III: Giomer. The samples underwent 500 cycles of thermocycling, with an immersion time of 60 seconds and a well time of 15 seconds, between 5 and 55°C. The samples were submerged in methylene blue dye for 24 hours at room temperature and dried. The samples were then divided into sections and examined with a stereomicroscope. Data was recorded and statistically analyzed. RESULTS: The least marginal microleakage was found in the ormocer group (1.22 ± 0.01) followed by resin-modified glass ionomer cement group (1.31 ± 0.07) and the giomer group (1.78 ± 0.03). There was a highly statistically significant difference found between resin-modified glass ionomer cement group and the ormocer group, resin-modified glass ionomer cement group and giomer group. And no significant difference was found between the ormocer group and the giomer group. CONCLUSION: The present study concluded that there was some amount of microleakage in primary teeth in all restorative materials examined in this in-vitro investigation. However, the marginal sealing ability of ormocer was found highest compared to resin-modified glass ionomer cement and Giomer materials. CLINICAL SIGNIFICANCE: The primary reason dental restorations fail, particularly in Class V cavities, is microleakage since the margins of these restorations are typically found in the dentin or cementum. Assessing microleakage is a crucial step in determining the marginal integrity of restorative materials. Developing methods and resources that reduce the adverse effects caused by the restorative marginal seal failing would benefit from this. How to cite this article: Al Ghwainem A, Alqarni AS. Comparative Assessment of Marginal Micro Leakage of Different Esthetic Restorative Materials Used on Primary Teeth: An In-vitro Study. J Contemp Dent Pract 2024;25(1):58-61.

Evaluation of Microleakage of Nanoparticle-incorporated Cyanoacrylate Root Canal Sealer Using the Radioisotopic Method: An In Vitro Study.

AIM OF THE STUDY: The study aimed to assess the microleakage of nanoparticle-based (NPB) cyanoacrylate sealer and epoxy resin-based (ERB) sealer using radioisotope method and confocal laser scanning microscopy (CLSM). MATERIALS AND METHODS: A total of 100 single-rooted teeth were collected; specimens were accessed, instrumented, and irrigated, and randomly distributed into 4 groups of 25 samples each: Group I: Positive control, group II: Negative control, group III: Obturated with NPB sealer, and group IV: Obturated with ERB sealer. All samples were immersed in 99mTc pertechnetate solution, for 3 hours after which radioactivity was estimated under a Gamma camera. The radioactivity released by specimens before and after nail varnish removal was statistically analyzed. After 2 weeks, the same samples were used for CLSM analysis. The sealer tubular penetration depth was measured at the deepest level for each group using ZEN lite 2012. Data collected was statistically evaluated. RESULTS: The amount of radioactivity observed at first in group III and group IV was 194.76 and 599.12 units, respectively, with p-value < 0.001, indicating significant interaction, and after nail varnish removal, it was 89.68 and 468.44 units, respectively, with a p-value < 0.001; again, indicating statistical significance. Hence, the radioactivity of NPB sealer was found to be lower than ERB sealer in both cases, indicating better sealing of the former. The photomicrographs show that mean value of dye penetration in NPB sealer in first, second, and third segment from apex was 85.06, 75.73, and 66.09, respectively; while in the case of ERB sealer, those were 597.28, 461.17, and 195.68, respectively; with p-value < 0.001; signifying that NPB sealer exhibited higher resistance to microleakage than ERB sealer. CONCLUSION: The NPB sealer can become a potential root canal sealer in future endodontics due to superior physiochemical properties attributed to the cyanoacrylate and incorporated nanoparticles. CLINICAL SIGNIFICANCE: The study clinically signifies that we can equally use the radioisotopic method along with confocal method while conducting the microleakage studies. In addition, NPB sealer can be an emerging replacement with better properties than gold standard root canal sealers for clinical use. How to cite this article: Shetty C, Qaiser S, Shetty A, et al. Evaluation of Microleakage of Nanoparticle-incorporated Cyanoacrylate Root Canal Sealer Using the Radioisotopic Method: An In Vitro Study. J Contemp Dent Pract 2024;25(4):335-341.

Comparative Evaluation of Microleakage of Fiber-reinforced Glass Ionomer Cement and Conventional Glass Ionomer Cement Restorations Immersed in Three Different Beverages: In Vitro Study.

AIM: The aim of the study was to compare and evaluate the microleakage of fiber-reinforced glass ionomer cement (GIC) and conventional glass ionomer cement restorations immersed in three different beverages. MATERIALS AND METHODS: A total of 96 human exfoliating deciduous molars were selected which were cleaned and disinfected. Standardized Class V cavity preparations were done and buccal surface were restored with experimental fiber-reinforced glass ionomer cement (Exp-FRGIC), lingual surface were restored with Type II conventional GIC. They were divided into four groups according to the test beverage. The samples were subjected to various immersion regimes and evaluated for microleakage under stereomicroscope. RESULTS: Intragroup comparison for (Exp-FRGIC) showed significant microleakage when immersed in fresh fruit juice at high immersion whereas intragroup comparison in conventional GIC, showed highest microleakage with soft drink. Intergroup comparison of (Exp-FRGIC) in high immersion regime, showed more microleakage with specimen immersed in soft drink followed by fresh fruit juice. CONCLUSION: It can thus be concluded that the three beverages used in the study affected the microleakage of both restorative materials significantly. CLINICAL SIGNIFICANCE: Increasing usage of fruit juices in the pediatric diet has a definite impact on the progression of caries and it directly or indirectly affects the quality of restorations placed in the oral cavity. How to cite this article: George MA, Chandak SA, Khekade SH, et al. Comparative Evaluation of Microleakage of Fiber-reinforced Glass Ionomer Cement and Conventional Glass Ionomer Cement Restorations Immersed in Three Different Beverages: In Vitro Study. J Contemp Dent Pract 2024;25(4):346-353.

Evaluation of the effect of high-intensity light-curing device on micro-leakage of pits and fissure sealants.

Reducing treatment time is one of the most important trends in modern dentistry. This study aimed to compare the micro-leakage around the resin sealants when using both high and conventional intensity light-curing systems. The study sample consisted of 30 extracted human maxillary premolar teeth that were divided into two equal groups according to the light-curing system used: Group 1, High-Intensity Light-Curing System and Group 2, Conventional Light-Curing System. Light-curing by Woodpecker I-LED device with two intensities (high and conventional) has been used. All teeth were subjected to 500 cycles of thermocycling. Then, a methylene blue dye microleakage test was performed, and the teeth were sectioned longitudinally and studied under a stereo microscope. The mean of micro-leakage in the high-intensity group (1.33 ± 1.29) was less than in the conventional intensity group (1.63 ± 1.29) without any statistically significant differences (p = 0.320). The high-intensity light-curing system mode may be a good and acceptable alternative to conventional intensity light-curing system mode in polymerization of pits and fissure sealants.

Micro-CT analysis and leakage of bioceramic retrofillings after ultrasonic and Er:YAG laser cavity preparations: an in vitro study.

The purpose of the study was to determine the influence of preparation techniques on marginal adaptation and sealing of Biodentine™ and TotalFill® RRM bioceramic retrograde fillings. Fifty-two single-root teeth extracted for periodontal reasons were used. Root canals were instrumented using Reciproc Blue #25 and obturated using a single cone technique with an AH Plus® root canal sealer. Retrograde cavities were prepared with Piezomed device (Piezo), Er:YAG laser in short-pulse(SP) and quantum square pulse(QSP) modes and filled with Biodentine™ (BD) or TotalFill® RRM (TF). There were 6 groups (n=8): (1) Piezo BD, (2) Piezo TF, (3) SP BD, (4) SP TF, (5) QSP BD, and (6) QSP TF, and positive and negative controls (n=2). Micro-CT analysis was performed on two samples from each group. Percentage volumes of internal and external voids in apical 1.5 mm were determined. Rhodamine B dye leakage was done on six samples. The samples were cut longitudinally and examined under a stereomicroscope. Digital recordings were analyzed in ImageJ software. The deepest penetration of color in mm was recorded. The data were statistically analyzed using ANOVA and Duncan's test at the level of significance α=0.05. TotalFill® RRM performed significantly better than Biodentine™ in terms of sealing (p<0.05) and marginal adaptation, as evaluated by micro-CT. Sealing was significantly better in SP compared to QSP mode preparations (p<0.05). Differences between Piezomed and laser modes were not significantly different (p>0.05). Sealing was statistically significantly better with TotalFill® RRM compared to Biodentine™ and in Er:YAG SP preparations compared to Er:YAG QSP.

In vitro evaluation of the sealing ability of combined use of iRoot BP Plus and iRoot SP for root-end filling.

OBJECTIVES: The aim of this in vitro study was to evaluate the sealing ability of combined application of iRoot BP Plus Root Repair Material (BP-RRM) and iRoot SP Injectable Root Canal Sealer (SP-RCS) for root-end filling. MATERIAL AND METHODS: A total of 120 extracted human teeth were used in this study and were randomly divided into four groups. The BP-RRM+SP-RCS group included teeth retro-filled with combined use of BP-RRM and SP-RCS (n=45), and the BP-RRM group included teeth retro-filled by BP-RRM alone (n=45). Teeth without root-end preparation and filling were equally divided into positive control (n=15) and negative control (n=15). The apical sealing ability was evaluated by micro-CT analysis, dye penetrant examination, bacterial leakage test, and glucose leakage test. RESULTS: Micro-CT analysis showed that the total void fraction of BP-RRM+SP-RCS group was significantly lower than that of BP-RRM group, particularly at the coronal 1/3 segment of the retro-filled roots. Consistently, the maximum linear depth of dye leakage in BP-RRM+SP-RCS group was less than that of BP-RRM group. Bacterial leakage test showed that the microbial leakage in BP-RRM+SP-RCS group was significantly less than that in BP-RRM group. However, no significant difference in glucose leakage between BP-RRM+SP-RCS group and BP-RRM group was observed. CONCLUSION: Combined use of BP-RRM and SP-RCS for root-end filling promotes apical sealing in vitro. CLINICAL RELEVANCE: Combined use of BP-RRM and SP-RCS for root-end filling exhibited better apical sealing as compared to BP-RRM alone in vitro, and this may help reducing technical sensitivity and promoting clinical efficiency during endodontic microsurgery.

3D-2D microleakage assessment of preheated bulk-fill composite resin applied with different parameters: a micro-CT analysis.

This study evaluated microleakage from class II cavities filled with bulk-fill composite preheated to different temperatures, applied at different thicknesses, and with different polymerization modes. A total of 60 mesio-occlusal cavity were drilled into the extracted human third molars at 2 mm and 4 mm thickness. Preheated bulk-fill composite resin (Viscalor; VOCO, Germany) was applied to the cavities at 68 °C and 37 °C after the adhesive resin was applied, and cured using standard and high-power light-curing modes of a VALO light-curing unit. An incrementally applied microhybrid composite was used as the control. The teeth were subjected to 2000 cycles of heating to 55 °C and cooling to 5 °C with a 30-s hold time. Then, they were immersed in a 50% silver nitrate solution for 24 h and scanned with micro-computed tomography. Scanned data were processed using the CTAn software. Two (2D) and three (3D) dimensional analyses of leached silver nitrate were performed. The data's normality was assessed using the Shapiro-Wilk test before comparisons using a three-way analysis of variance. In both 2D and 3D analysis, bulk-fill composite resin preheated to 68 °C and applied at 2 mm thickness showed less microleakage. In the 3D analysis, restorations applied at 37 °C and 4 mm thickness in high-power mode showed significantly higher values (p < 0.001). Preheated bulk-fill composite resin can be applied at 68 °C and effectively cured at both 2 mm and 4 mm thickness.

Comparison of the marginal microleakage of a bioactive composite resin and traditional dental restorative materials.

The primary objective of this study was to evaluate the marginal microleakage of Activa Kids BioActive-Restorative used with an adhesive bonding agent (AB+) and compare it with the microleakage of a traditional composite resin (CR), a resin-modified glass ionomer cement (RMGIC), and Activa Kids BioActive-Restorative placed without the use of an adhesive bonding agent (AB-). Standard Class I cavities were prepared in 200 extracted, caries-free permanent molars, which were then restored with 1 of the 4 restorative materials (n = 50 each). The restored teeth were thermocycled for 500 cycles, alternating between 5°C and 55°C with a dwell time of 25 seconds; stained with basic fuchsin dye with a soak time of 24 hours; and sectioned buccolingually. Microleakage was assessed independently by 2 evaluators who viewed specimens under a dissecting microscope at ×30 magnification and assigned scores according to a standardized microleakage scale. Because a Spearman correlation test showed a high correlation between the scores assigned by the 2 evaluators, their ratings for each of the 4 test groups were pooled, and a modified Wilcoxon rank sum test (P < 0.05) was used to analyze the microleakage scores. No difference in microleakage was observed between the AB+ and CR groups (P = 0.8652). Statistically significant differences in microleakage were observed between the AB+ and RMGIC groups (P < 0.0001) as well as between the AB+ and AB- groups (P = 0.0324). The results showed that AB+ had a mean microleakage rate comparable to that of traditional CR. Moreover, AB+ exhibited a lower mean microleakage rate than RMGIC; both the bioactive composite resin and RMGIC are fluoride-releasing materials, so clinicians should consider using AB+, especially in high-caries-risk patients, who are vulnerable to recurrent caries resulting from microleakage and benefit from fluoride release. In this study, AB+ exhibited a significantly lower mean microleakage rate than AB-; therefore, this bioactive material should be used with a bonding agent.

Effect of Prolonged Water Aging on the Bond Strength and Marginal Seal of Three Novel Restorative Materials.

AIM: To assess and contrast the shear bond strength (SBS) and microbial leakage of Cention-N, Fuji IX, and nanohybrid composite restorative materials after being exposed to prolonged water aging. MATERIALS AND METHODS: A total of 30 self-curing acrylic blocks were prepared for SBS analysis. Extracted teeth were affixed on the acrylic resin to incorporate the root section. To expose the occlusal dentin, 3 mm of the midcoronal portion was sectioned. The sectioned samples were allocated into the following three groups: Group I: Fuji IX; group II: Filtek Z350; and group III: Cention-N. Cylindrical plastic tubing was used to place each material as directed by the manufacturer and water aging for 7, 14, and 28 days at 37°C. Also, a universal testing machine (UTM) was utilized for testing followed by a scanning electron microscope (SEM). For microleakage analysis, a total of 30 class-V cavities were prepared. The prepared samples were allotted to respective groups; Later, 200 thermocycles at 5°C and 55°C were applied for 30 seconds to mimic the oral environment. The root apices sealed with sticky wax and the exception of a 1-mm around the edges of the restorations were then painted twice with clear nail varnish and submerged in 0.5% basic fuchsin dye at 37°C. Samples were washed, dried, and sectioned longitudinally followed by stereomicroscopic evaluation. RESULTS: Groups I (0.083), group II (0.083), and group III (0.102) did not show significant variation in the SBS after water degradation. At the end of 28 days of water aging, group III showed 33.3% adhesive failure and 66.7% mixed failure mode. For marginal leakage in group III, the mean and standard deviation (SD) were 334.90 ± 418.454 with the p = 0.001 showing a significant difference compared to groups I and II. CONCLUSION: Compared to nanohybrid composite and Fuji IX, Cention-N showed a superior SBS after being exposed to water aging and exhibited lesser marginal leakage. CLINICAL SIGNIFICANCE: Cention-N outperformed in its marginal adaptation with superior shear resistance and can be considered as an alternative bulk filling material.

Evaluating the effect of three fissure preparation techniques on microleakage of a colored flowable composite used as a fissure sealant.

Pit and fissure sealants play an essential role in preventive dentistry. This study evaluates the microleakage levels of a new and colored flowable composite applied as a sealant after three preparation techniques. A total of 24 non-carious mandibular permanent molars with deep pits and fissures were included in the study. Pit and fissures were prepared with 37% phosphoric acid, tungsten carbide bur and fissurotomy burs (SS WHITE Dental, New Jersey, USA) using conventional, enameloplasty and fissurotomy techniques. All samples were thermocycled following the placement of Rainbow Flow (PPH CERKAMED Wojciech Pawlowski, Poland) as a sealant and sections were taken after immersion in methylene blue dye. The microleakage levels of the samples were examined under a stereomicroscope (Olympus SZX-7 Olympus SZ-61 Stereo Microscope) at 2.8× magnification to analyze the dye penetration of the flowable composite. The 144 sections were examined and scoring for microleakage was done by examining the dye penetration from the occlusal border to the base of the fissure. Considering all sections regardless of the preparation technique, it was found that 16.6% of the sections have no leakage. Regarding the microleakage scores, the mean score of the conventional group was 1.87 ± 0.98, the mean score of the enameloplasty group was 1.88 ± 1.14, and the mean score of the fissurotomy group was 1.81 ± 1.1. The median scores of the conventional, enameloplasty and fissurotomy groups were 2, 2 and 1.5, respectively. The present study reports no difference between the microleakage level of a colored flowable composite material used as a pit and fissure sealant following three fissure preparation techniques and supports the clinical use of this material.

Impact of access cavity cleaning on the seal of postendodontic composite restorations in vitro.

AIM: The aim of the study was to investigate the influence of cavity cleaning and conditioning on marginal integrity of directly placed post-endodontic composite class-I-restorations in vitro. METHODOLOGY: A total of 168 fully intact teeth without caries or fillings received pre-endodontic composite restorations (class-II) after their extraction. Occlusal endodontic access-cavities were prepared, and root canals were instrumented and filled with gutta-percha and an epoxy resin-based sealer. Prior to post-endodontic class-I-restoration, access cavities were completely contaminated with sealer, cleaned with alcohol and pre-treated as follows: cleaner only (alcohol), glycine-polishing, Al2 O3 sandblasting, carbide bur (immediate as well as delayed restoration). A positive control (not contaminated with sealer and adhesive used) and negative control (cleaner used but no adhesive) were established. Half of the teeth from each group were subjected to thermocycling and mechanical loading (TCML). Marginal integrity of post-endodontic restoration was evaluated in oro-vestibular or mesio-distal sections after AgNO3 dye penetration (DP) by standardized photomacroscopic imaging and expressed in per cent of margin length along all segments and separately for enamel, dentine and composite, respectively. Results were analysed non-parametrically (α = .05). RESULTS: No restorations or teeth fractured or debonded completely. Without TCML, the median DP of all segments was significantly higher for the negative control compared with all other groups in oro-vestibular cutting direction (53%; p = .002) and in mesio-distal cutting direction (51%; p ≤ .041). The other groups without TCML revealed 16%-24% DP (oro-vestibular) and 12%-24% DP (mesio-distal). With TCML, the median DP in oro-vestibular cutting direction for all segments ranged between 48% and 62% for all groups, a significant difference was only observed between glycine-polishing and carbide bur (p = .041). In mesio-distal cutting direction, the median DP in negative control was 69% with TCML and significantly higher compared with all other groups (p = .002). For all other groups, the median DP of all segments ranged between 28% and 40% with TCML without significant differences. Error rates method (k = 7) revealed a significant influence of TCML in general on penetration of all segments in both oro-vestibular and mesio-distal cutting directions. CONCLUSION: Additional access cavity pre-treatment after alcohol cleaning did not improve the marginal integrity of post-endodontic composite restorations. Thorough cleaning of the access cavity with alcohol seems to assure an acceptable marginal integrity to the tooth and restorative composite.