Spectrophotometric analysis evaluating apical microleakage in retrograde filling using GIC, MTA and biodentine: an in-vitro study.

BACKGROUND: The present study compares the apical microleakage of three different root-end filling materials in which the retrograde cavity is prepared by two different burs. METHODS: Eighty extracted single rooted maxillary and mandibular premolars were taken. Root canal treatment was completed. Apical 3 mm of all the teeth were resected with diamond disk. The tooth were divided into four groups with two subgroups for each group containing 10 tooth (N = 10) as: Group IA (Negative Control and IB (Positive Control); Group IIA and IIB: Prepared with round carbide bur and round diamond bur respectively, filled with GIC; Group IIIA and IIIB: Prepared with round carbide bur and round diamond bur respectively, filled with MTA; Group IVA and IVB: Prepared with round carbide bur and round diamond bur, filled with Biodentine. After applying two coats of nail varnish leaving apical 3 mm (except for negative control group) all teeth were immersed in 2% methylene blue for 3 days and again in 65% nitric acid for next 3 days for extraction of dye. The obtained solution was then transferred to eppendorf tube and centrifuged in microcentrifuges at 14,000 revolution per minutes (RPM) for 5 min. Optical density or absorbance of the supernatant solution was measured with UV spectrophotometer at 550 nm. RESULTS: The absorbance of the supernatant solution after dye extraction is decreasing in the order of positive control> GIC > MTA > Biodentine> negative control group. The significant difference was observed between GIC and MTA (p = 0.0001) and GIC and Biodentine (p = 0.0001) with two different burs but statistically non-significant difference was observed between MTA and Biodentine with Carbide bur (p = 0.127) and Diamond bur (p = 0.496) respectively. CONCLUSIONS: Within the limitations of the present study, it can be concluded that Biodentine and MTA showed less microleakage as compared to GIC. There is no significant difference between mean microleakage of MTA and Biodentine. However, the mean OD of the Biodentine was least of all evaluated materials. Preparation of the root-end using round carbide bur as well as round diamond burs showed comparable microleakage for all three filling materials.

Microleakage of composite crowns luted on CAD/CAM-milled human molars: a new method for standardized in vitro tests.

OBJECTIVES: To investigate debonding of full crowns made of CAD/CAM composites, CAD/CAM technology was applied to manufacture standardized test abutments to increase the reproducibility of human teeth used in in vitro studies. MATERIALS AND METHODS: A virtual test abutment and the corresponding virtual crown were designed and two STL data sets were generated. Sixty-four human third molars and CAD/CAM blocks were milled using a CNC machine. Crowns of four different composite blocks (Lava Ultimate (LU), Brilliant Crios (BC), Cerasmart (CS), Experimental (EX)) were adhesively bonded with their corresponding luting system (LU: Scotchbond Universal/RelyX Ultimate; BC: One Coat 7 Universal/DuoCem; CS: G-PremioBond/G-Cem LinkForce; EX: Experimental-Bond/Experimental-Luting-Cement). Half of the specimens were chemical-cured (CC) and the others were light-cured (LC). Afterwards, specimens were artificially aged in a chewing simulator (WL-tec, 1 million cycles, 50-500 N, 2 Hz, 37 °C). Finally, a dye penetration test was used to detect debonding. For inspection, the specimens were sliced, and penetration depth was measured with a digital microscope. Data were analyzed with the Mann-Whitney U test. RESULTS: No cases of total debonding were observed after cyclic loading. However, the LC specimens showed a significantly lower amount of leakage than the CC ones (p < 0.05). Furthermore, the CC specimens exhibited broad scattering. Only the LC-EX blocks showed no debonding. The CC-CS blocks showed the highest leakage and scattering of all tested specimens. CONCLUSIONS: Natural human teeth can be manufactured by CAD/CAM technology in highly standardized test abutments for in vitro testing. For CAD/CAM composites, light curing should be performed. CLINICAL RELEVANCE: The success of a restoration depends on the long-term sealing ability of the luting materials, which avoids debonding along with microleakage. For CAD/CAM composites, separate light curing of the adhesive and luting composite is highly recommended.

Influence of a calcium hydroxide-based intracanal dressing on the quality of the root canal filling assessed by capillary flow porometry.

OBJECTIVE: The objective of this study is to evaluate the influence of a calcium hydroxide intracanal dressing (CH) on the short- and long-term sealing ability of the root canal filling using capillary flow porometry (CFP). MATERIALS AND METHODS: To verify the repeatability of the method, five obturated specimens were submitted to CFP. Measurements were repeated three times and compared with the non-parametric Friedman test. Forty-five instrumented palatal roots were randomly divided into three groups. Group 1: specimens were obturated in one step without placement of any dressing. Group 2: CH was placed and removed after 1 week with syringe irrigation before obturation. Group 3: CH was placed and removed after 1 week with ultrasonic activation before obturation. CFP measurements were conducted at 1 week and 6 months after obturation. The inter-group comparisons were performed using the Kruskal-Wallis test and the intra-group comparison over time using the Wilcoxon signed-rank test. Significance level was set at 0.05. RESULTS: In the five specimens, no difference could be detected between the consecutive measurements for minimum, mean flow, and maximum pore diameter indicating repeatability of the method. No difference in sealing ability could be detected neither between the 3 groups at 1 week and at 6 months nor within each group between the 1 week and the 6 months measurements. CONCLUSIONS: Placement of a CH did not affect significantly the short- and long-term sealing ability of the root canal filling. CLINICAL RELEVANCE: The use of an intermediary CH does not negatively influence the quality of the root canal filling.

Microleakage of Different Adhesive Systems in Primary Molars Prepared by Er: YAG Laser or bur.

BACKGROUND AND AIM: This study aimed to examine the microleakage of class V cavities of primary molars prepared by either a conventional dental bur or Er:YAG laser and one of two different adhesive systems. METHODS: A total of 50 tooth samples from primary molars were used in this study. They were randomly assigned into five experimental groups of 10 samples each, according to the cavity preparation technique and the type of adhesive system applied to the cavities. Following cavity preparation, etching, bonding, and filling steps, samples were dyed using basic fuchsine and were sectioned longitudinally in buccolingual direction. Percentages of dye penetration at gingival and occlusal margins were calculated for each group. RESULTS: Overall, microleakage scores of gingival margins were significantly higher than those of occlusal margins (P < 0.001). The group that underwent laser preparation, laser etch, and self-etch bonding procedures had worse microleakage scores for gingival margins. However, all groups had similar occlusal scores (P > 0.05). CONCLUSION: Self-etch bonding systems and cavity preparation with Er:YAG laser may be an alternative to conventional restoration of primary molars with compomers. Further studies are warranted to fully elucidate the effect of laser-based etching techniques in cavities prepared by laser.

Comparison of three in vitro implant leakage testing methods.

AIMS: To assess the accuracy and sensitivity in detecting implants leakage with a gas-enhanced permeation test (GEPT) and to compare with a molecular- and a bacterial-based leakage tests. MATERIALS AND METHODS: Three implants systems were tested (n = 20 per group): Nobel Biocare (NB), Astra Tech (AT) and Biomet 3i (B3i). Implants were mounted in PVC disks and were first tested for gas pressure change and infiltrated saline volume over 40 min. The same implants were then subjected to a molecular leakage evaluation using fluorescent Dextran for 28 days. After cleaning and sterilization, bacterial permeation (E. faecalis) was evaluated by selective media turbidity for another 28 days. Slopes in the pressure change and the perfused saline rate were used as a measure of leakage in the GEPT model and the times of positive events, that is, color change, after molecular and bacterial tests were recorded. Data were analyzed using Kolmogorov-Smirnov/Shapiro-Wilk, Kruskal-Wallis H and Spearman's Rho tests (P < 0.05). RESULTS: The gas and saline (ml) leakage values accounted for 0.85 ± 0.71 and 0.56 ± 0.50 ml (AT), 0.23 ± 0.030 and 0.12 ± 0.20 ml (NB) and 0.01 ± 0.01 and 0 ± 0 ml (B3i), respectively, and were significantly different from each other (P < 0.001). Slope in the pressure change over time showed a significant positive correlation with the collected saline solution (r = 0.91; P < 0.001). Molecular and bacterial leakage was positive at the same implants, which also showed increased leakage values in the GEPT setup. The development of positive events in the timeline of the bacterial leakage evaluation corresponded well to the GEPT leakage model. CONCLUSION: The GEPT proved to be a reliable method to quantify leakage. The B3i showed the best sealing among the tested systems.

Accuracy of digital images in the detection of marginal microleakage: an in vitro study.

PURPOSE: To evaluate the accuracy of Image Tool Software 3.0 (ITS 3.0) to detect marginal microleakage using the stereomicroscope as the validation criterion and ITS 3.0 as the tool under study. MATERIALS AND METHODS: Class V cavities were prepared at the cementoenamel junction of 61 bovine incisors, and 53 halves of them were used. Using the stereomicroscope, microleakage was classified dichotomously: presence or absence. Next, ITS 3.0 was used to obtain measurements of the microleakage, so that 0.75 was taken as the cut-off point, and values equal to or greater than 0.75 indicated its presence, while values between 0.00 and 0.75 indicated its absence. Sensitivity and specificity were calculated by point and given as 95% confidence interval (95% CI). RESULTS: The accuracy of the ITS 3.0 was verified with a sensitivity of 0.95 (95% CI: 0.89 to 1.00) and a specificity of 0.92 (95% CI: 0.84 to 0.99). CONCLUSION: Digital diagnosis of marginal microleakage using ITS 3.0 was sensitive and specific.

Potential systematic error in laboratory experiments on microbial leakage through filled root canals: an experimental study.

AIM: To assess the routes of bacterial leakage in a commonly used two-chamber model designed to evaluate root fillings. METHODOLOGY: Fifty-one intact human mandibular premolars with fully developed roots were used. They were left completely intact (n=23), or were accessed, instrumented and either left open (n=5) or root filled with gutta-percha and AH Plus (n=23). All teeth were sealed between two chambers using sticky wax. The apical root aspects were left uncovered. The upper chamber was seeded with Enterococcus faecalis. An enterococci-selective broth was used in the lower chamber. Leakage was assessed for 120 days and compared using survival statistics (α<0.05). Subsequently, roots were trans-sected, stained using a 'live' DNA stain (Syto59) and inspected using confocal laser scanning microscopy. An E. faecalis-specific RNA probe was used for fluorescence in situ hybridization (FISH). RESULTS: Leakage started to occur from day 56, with further occurrence essentially identical between root filled teeth and intact counterparts (P=0.71). All the trans-sections showed fluorescence related to Syto59 between the cementum layer and the sticky wax. Fluorescence was also observed between the root filling and the tubular dentine, whilst it was absent at the interface between root filling and sclerotic dentine. Secondary dentinal tubules, i.e. lateral branches connecting the main counterparts, contained fluorescent material. FISH revealed that Syto59 exclusively stained E. faecalis. CONCLUSIONS: The current experimental method proved to be unsuitable to compare root fillings. Histology revealed interesting observations regarding the relationship of dentine structure and bacterial leakage, which warrant further investigation.

Novel methodology to evaluate the effect of residual moisture on epoxy resin sealer/dentine interface: a pilot study.

AIM: To evaluate the sealer/dentine interface associated with an epoxy resin sealer using the combination of Goldner's trichrome stain (GTS) and scanning electron microscopy (SEM) to verify the use of the experimental methodology. METHODOLOGY: Extracted human maxillary incisors (6) were subjected to root canal treatment. Subsequent to pulp removal, canal instrumentation and smear layer removal using EDTA and NaOCl, teeth were randomly and equally assigned to a 'wet' or 'dry' group. The 'dry' group was desiccated (95% ethanol/suction/paper points/air-drying), whilst the 'wet' group was treated with a saline rinse/suction/single paper point. Canals were then filled with an epoxy-based resin sealer and warm vertical gutta-percha compaction. After 7-day storage at 37°C, roots from each group were sectioned into apical, middle and coronal horizontal subsections that were cut and split into paired halves and evaluated with GTS or SEM. With GTS sections, hybrid layer and sealer tubular penetration were measured (n=15 measurements/intracanal location/condition) and evaluated using a two-factor repeated measures analysis of variance. The SEM qualitative analysis of paired sections was included as a complementary confirmation of GTS analyses. RESULTS: In dry and wet groups, there was no conspicuous sealer/dentine interface hybrid layer, irrespective of canal location. However, dry specimens exhibited more uniform sealer distribution with deeper tubular penetration in the coronal and middle third (P<0.05). In contrast, there was decreased sealer distribution and tubule penetration in the apical third, regardless of moisture condition (P<0.05). CONCLUSIONS: The experimental methodology (combination of GTS and SEM) can be used to evaluate the intracanal resin sealer/dentine interface. The pilot data indicated that thorough drying of the root canal system may result in improved epoxy resin sealer distribution and deeper resin sealer tubular penetration, especially in the coronal and middle thirds of root canals.

An in vitro study to assess glucose microleakage along fiber posts cemented with 2- and 3-step etch-and-rinse resin adhesive systems.

The aim of the study is to compare the sealing ability of two adhesive systems. Thirty teeth were endodontically treated and were randomly assigned to 2 groups: G 1 - 3-step adhesive (Solobond-Plus) and G 2 - 2-step adhesive (Solobond-M). Posts containing glass fiber were cemented using the adhesive technique recommended by the manufacturer. All samples were mounted on a glucose leakage model. A 10 microL aliquot of solution was drawn from the glass bottle using a micropipette. The samples were then analyzed in a UV-Vis spectrophotometer. The two tested adhesive systems presented a similar capacity to prevent the glucose infiltration.

Microleakage evaluation using acetate peel technique.

OBJECTIVES: To evaluate and measure the interfacial space or the restoration cavity integrity for probable microleakage using acetate film; acetate peel technique under different magnifications. STUDY DESIGN: Premolar tooth was obtained and standardized class V restoration with Z-350 done both buccally and lingually. The tooth was hemisectioned buccolingually and embedded in epoxy resin, polished, acid etched, washed and dried. The sectioned sample was flooded with acetone and a pre-cut acetate film placed over it. As the acetone evaporated, the film took the shape of the micro relief produced by etching and dried in 10-15 mins. It was pulled off the tooth surface and mounted between two glass slides for examination under research microscope with different magnifications. RESULTS: This enabled us to measure the interfacial space that might lead to leakage of restoration and also could detect the intricate details of tooth. CONCLUSION: The acetate peel technique is an efficient way to study the interfacial space/restoration-cavity marginal integrity at a higher magnification and was a fast and reliable tool for assessing the microleakage of a restorative material.

En face optical coherence tomography investigation of apical microleakage after laser-assisted endodontic treatment.

The aim of our study was to evaluate the potential of en face optical coherence tomography (OCT) for the detection of apical microleakage after 980 nm and 1,064 nm laser-assisted endodontic treatment. Ninety, human, single-rooted teeth with one straight root canal and closed apices were used. All roots were prepared biomechanically to the working length at an apical size 30 and 0.06 taper. The teeth were divided into three equal groups of 30 samples each, according to the treatment to be applied to the root canal. Group I received 980 nm diode laser (3 W, 0.01 s on time, 0.01 s off time, 5 s per procedure, four procedures); group II received neodymium:yttrium-aluminum-garnet (Nd:YAG) laser (1.5 W, 15 Hz, 5 s per procedure, four procedures). In group III the root canals were approached conventionally only. In all groups the root canal filling was performed with AH Plus endodontic sealer and gutta-percha points. An en face OCT prototype was used for the investigation of apical microleakage. According to one-way analysis of variance (ANOVA) and en face OCT, the number of defects in the laser groups was significantly lower (P < 0.005) than in the control group. No statistical differences were noted between the laser groups (P = 0.049). En face OCT imaging proved that laser-assisted endodontic treatment improved the prognosis of root canal filling and led to a reduction in apical microleakage.

Assessment of different dyes used in leakage studies.

The goal of this in vitro study was to identify the most suitable dye for endodontic dye leakage studies, which could be a further step towards standardisation. The root canals of 70 extracted, single-rooted human adult teeth were enlarged to apical size 50 using hand instruments. The teeth were divided into seven groups (n = 10 each), and all root canals were completely filled by injection with one of the following dyes: methylene blue 0.5% and 5%, blue ink, black ink, eosin 5%, basic fuchsin 0.5% and drawing ink. Transverse root sections from the coronal, middle and apical part of the roots were examined, and the percentage of the dentine penetrated by dye was evaluated by software-supported light microscopy. In addition, the range of particle size of drawing ink particles was evaluated. There were conspicuous differences in the relative dye penetration into the root dentine and the penetration behaviour in the different root sections (two-way ANOVA, both p < 0.0001). One dye (drawing ink) penetrated less into the root dentine compared with all the others (p <0.0001). The particle size of this agent (0.1-2 microm) corresponds best with the size range of a representative selection of 21 species of pathogenic endodontic bacteria. Compared to the other dyes tested, drawing ink appears to be superior for use in endodontic dye leakage studies. The penetration behaviour into the root dentine of all the other dyes tested might be one factor that limits the applicability of these dyes in dye leakage studies.

Nanoleakage of current self-etch adhesives bonded to artificial carious dentin.

PURPOSE: To evaluate the nanoleakage of one- and two-step self-etch adhesives bonded to artificial carious dentin. METHODS: Deep dentin of 24 human molars was exposed and divided into four groups. One group served as control while the others were demineralized in artificial demineralization solution for 10 minutes, 6 hours, and 24 hours. Roots were sectioned and the crowns were bonded with one- and two-step self-etch adhesives (Clearfil S3 and Clearfil SE Bond) then restored with flowable composite (Estelite Flow Quick). Specimens were exposed to intrapulpal pressure through a tube connected to a barrel filled with silver nitrate solution in total darkness for 24 hours and then sectioned into two mid-slabs that were photo-developed and prepared for nanoleakage evaluation using FE-SEM and EDX. Penetration of silver into the hybrid and adhesive layers was evaluated and compared between adhesives and dentin condition. Data were statistically analyzed by Kruskal-Wallis test (alpha = .05). RESULTS: Increasing depths of demineralization were observed with increasing demineralization time. There were statistically significant differences for both adhesives (P < 0.05) and dentin demineralization (P< 0.05) in hybrid and adhesive layers. Normal dentin interfaces revealed no or slight nanoleakage regardless of adhesive. The bonded interface treated with one-step Clearfil S3 showed significant differences between normal and demineralized dentin. Also a trend towards increases in nanoleakage with the increasing of the demineralization time was demonstrated. Different patterns of nanoleakage were observed within adhesives.

Cross-sectional assessment of apical dye penetration following three endodontic obturation techniques.

This study sought to investigate apical leakage following three endodontic obturation techniques. Fifty-one recently extracted maxillary and mandibular canines were decoronated at the cementoenamel junction (CEJ) level and a size 10 file was passed to the exit of the apical foramen. Working distance was established 0.5 mm from where the file could be seen exiting the apical foramen. All teeth were instrumented using Brasseler Sequence files to a .06 taper size 40 file at working distance. The teeth were randomly divided into three groups: Group A (lateral condensation of gutta-percha with Roth's 811 Elite sealer), Group B (gutta-percha with GuttaFlow sealer), and Group C (Activ GP gutta-percha cone with Activ GP glass ionomer sealer). Two groups of three teeth served as positive and negative controls. There were no significant differences between Groups A and B; however, Group C was significantly different from Groups A and B.

Effect of tooth preparation on sealant success--an in vitro study.

This study compared the depth of penetration and marginal leakage of filled and unfilled sealants, with and without tooth preparation. One hundred and twenty extracted human third molar teeth that were free of restorations, fluorosis, caries, and sealants were used. After adequate storage and surface debridement, the teeth were randomly divided into four groups of 30 teeth each. In two groups, the occlusal surfaces were left intact, while in the other two groups, the occlusal surfaces were prepared using a diamond bur. Teeth in two groups were sealed with a filled sealant, and an unfilled sealant was used to seal teeth in the other two groups. The sealed teeth were then prepared for marginal leakage, immersed in 5% methylene blue (at 37 degrees C) for 24 hours. Subsequently, buccolingual sections were made and each section was examined for sealant penetration and marginal leakage, using a stereomicroscope. The depth of dye penetration and marginal leakage was evaluated according to a method described by Ovrebo and Raadal. The unfilled sealant placed after tooth preparation showed better enamel fissure penetration and less marginal leakage than the filled sealant.

Ultramorphological characterization of the resin dentin interface--an in vitro analysis of nanoleakage patterns of dentin adhesives.

AIM AND DESIGN: The requirements of an effective dentin adhesive system include the ability to thoroughly infiltrate the collagen network and partially demineralized zone, to encapsulate the collagen and hydroxyapatite crystallites, to produce a well polymerized durable hybrid layer with high bond strengths. Microleak-age and marginal percolation are the most detrimental factors thwarting the success of any restoration. However the presence of leakage pathways, called nanoleakage have been observed in the hybrid layer, even in the absence of microleakage. The nanoleakage patterns of four dentin adhesives (Prime & Bond NT, AdheSE, Clearfil S3 bond and Fuji Bond LC) was compared using Scanning electron microscopy and Energy Dispersive Spectroscopy, by the silver nitrate penetration method. RESULTS AND CONCLUSION: The results indicated that etch and rinse adhesives showed the maximum nanoleakage followed by the self etch systems. The glass ionomer based bonding agents showed the least nanoleakage. It is extremely important to take nanoleakage as a consideration while choosing dentin adhesives, to ensure success of the restoration.

Evaluación de la filtración apical al utilizar dos selladores biocerámicos / Evaluation of apical leakage when using two bioceramic sealers

Objetivo: Evaluar con técnica de diafanización el gra-do de filtración apical al utilizar dos selladores bio-cerámicos y la técnica de cono único con taper ex vivo. Materiales y métodos: Se utilizaron 60 premola-res inferiores humanos uniradiculares extraídos. La instrumentación se realizó con lima Primary 25/.07 (WaveOne Gold, Dentsply Maillefer), según protocolo del fabricante. Se irrigó con NaOCl 2,5% y EDTAC 17%. Para la obturación, la muestra se dividió aleatoria-mente en 4 grupos (n=15). Grupo 1: Cono único y Bio C Sealer. Grupo 2: Cono único y MTA Fillapex. Grupo control negativo: no se obturó. Grupo control positi-vo: Cono único y AH Plus. En todas las muestras se aplicaron dos capas de esmalte para uñas en toda la superficie dentaria con excepción del tercio apical y del grupo control positivo, que se esmaltó en su tota-lidad. Medio de filtración: tinta china negra por difu-sión pasiva. Se diafanizó con técnica de Robertson. Se usó programa AutoCad 2022, para medir filtración en milímetros lineales. Los datos se analizaron me-diante prueba de Kruskal-Wallis seguida por compa-raciones post hoc empleando el método de Conover (p<0,05, significativo). Resultados: La filtración con Bio C Sealer, MTA Fillapex, control negativo y control positivo tuvo una media (mínimo-máximo) de 0 (0-2), 1 (0-3), 6 (2-12) y 0 (0-0); sin diferencias significativas entre Bio C Sealer y MTA Fillapex (p>0,05), ni entre Bio C Sealer y control positivo (p>0,05); pero con di-ferencias significativas entre MTA Fillapex y control positivo (p<0,05), y entre control negativo y cual-quiera de los otros tres grupos (p<0,05). Conclusión: La obturación con Bio C Sealer lograría un nivel de sellado similar al que se obtiene con el control po-sitivo; mientras que la obturación con MTA Fillapex produciría un sellado ligeramente menos efectivo que el control positivo. Sin embargo, la filtración no variaría sustancialmente entre obturaciones con Bio C Sealer y MTA Fillapex (AU)

Objective: To evaluate the degree of apical filtration with diaphanization technique, using two bioceramic sealers and single cone technique with taper, ex vivo. Materials and methods: 60 extracted single-root human mandibular premolars were used. The instrumentation was carried out with primary file 25/.07 (WaveOne Gold, Dentsply Maillefer), according to the manufacturer's protocol. Irrigation was done with 2.5% NaOCl and 17% EDTAC. For obturation, the sample was randomly divided in 4 groups (n=15). Group 1: Single cone and Bio C Sealer. Group 2: Single cone and MTA Fillapex. Negative control group: it was not obturated. Positive control group: Single cone and AH Plus. In all samples, two layers of nail polish were applied to the entire tooth surface with exception of apical third and the positive control group, which was completely glazed. Filtration medium: black Chinese ink by passive diffusion. It was diaphanized with Robertson technique. AutoCad 2022 program was used to measure filtration in linear millimeters. Data were analyzed using Kruskal-Wallis test, followed by post hoc comparisons using Conover method (p < 0.05, significant). Results: Filtration with Bio C Sealer, MTA Fillapex, negative control and positive control had a mean (minimum-maximum) of 0 (0-2), 1 (0-3), 6 (2-12) and 0 (0-0); no significant differences between Bio C Sealer and MTA Fillapex (p > 0.05), nor between Bio C Sealer and positive control (p > 0.05); but with significant differences between MTA Fillapex and positive control (p < 0.05), and between negative control and any of the other three groups (p < 0.05). Conclusion: Obturation with Bio C Sealer would achieve a level of sealing similar to obtained with the positive control; while obturation with MTA Fillapex would produce a slightly less effective seal than the positive control. However, filtration would not vary substantially between fillings with Bio C Sealer and MTA Fillapex (AU)

Similar glucose leakage pattern on smear-covered, EDTA-treated and BioPure MTAD-treated dentin.

This study assessed the effect of BioPure MTAD on the sealing ability on the basis of the filtration rate of glucose along the root fillings. Both 17% ethylenediaminetetraacetic acid (EDTA) and smear-covered dentin were used as reference patterns to compare the results. Sixty-four human upper incisors were prepared with different irrigation protocols (n = 18): G1, NaOCl; G2, NaOCl + EDTA; and G3, NaOCl + BioPure MTAD. The teeth were obturated and then prepared in a double-chamber apparatus to evaluate the glucose leakage along the root fillings. The amount of glucose leakage was quantified with spectrophotometry at 7, 14, 21, 28, 35, 42, 49, and 56 days. Leakage existed in every sample and was variable in all of the experimental groups, and Kruskal-Wallis H test results showed that there were no significant differences among the experimental groups (P > .05). The smear-covered dentin did not allow more glucose leakage than EDTA-treated and BioPure MTAD-treated dentin.