Type Of Sealer Research Articles

Push-Out Bond Strength of EndoSeal Mineral Trioxide Aggregate and AH Plus Sealers after Using Three Different Irrigation Protocols.

The current study was designed to assess the bonding strength of EndoSeal MTA and AH Plus sealers after using three irrigation protocols as follows: (1) 17% Ethylenediamine tetraacetic acid, (2) 7% maleic acid, and (3) 37% phosphoric acid. Push-out bond strength was evaluated for 60 middle root slices of 1-mm thickness each. They were horizontally cut from freshly extracted single-rooted human teeth. A hole in the root canal was made using a carbide round bur of 1.1 mm in diameter in a middle third root slice. Specimens were dipped in 2.5% NaOCl, and then they were grouped into three groups; G1: 17% EDTA, G2: 7% maleic acid, and G3: 37% phosphoric acid as a final irrigant for 3 minutes. Each group was subdivided into two subgroups, according to the type of sealer, either EndoSeal MTA or AH Plus. After the full set of the sealer, the bond strength was evaluated with the push-out test by applying a force to each slice using a plunger with a 1-mm diameter. The one-way Tukey's post hoc test, analysis of variance (ANOVA) test, and Student's t-test were utilized to gather data and statistically evaluate it. The irrigation protocol used exhibited significant influence on the bond strength of EndoSeal MTA and AH Plus sealers. AH Plus sealer subgroups showed the highest bond strength with 7% maleic acid, followed by 37% phosphoric acid, and 17% EDTA. While in the EndoSeal MTA sealer subgroups, the highest bond strength was shown with the 17% EDTA followed by 7% maleic acid and 37% phosphoric acid, respectively. The present study revealed that the type of the final irrigant significantly impacts the bond strength of the sealer used. The AH Plus sealer bond strength was improved by using the 7% maleic acid as a final irrigant. In contrast, the EndoSeal MTA sealer showed the best results with the 17% EDTA as a final irrigant.

The benefit of tissue sealant on urethroplasty in hypospadias patients – A systematic review and meta-analysis

Background: Hypospadias was ranked second after undescended testis as the most prevalent congenital abnormality in newborn males. Hypospadias can be successfully repaired through multiple surgeries in the majority of children. Postoperative complications were not rarely seen after surgeries, such as urethrocutaneous fistula (UCF), meatal stenosis, and glans breakdown. Tissue sealant application in hypospadias repair serves as additional suture line coverage and reduces the post surgery complications5.However, the effects of sealants usage during urethroplasty are still uncertain. This review aimed to know the effects of tissue sealant usage on patients with hypospadias who undergo urethroplasty. Methods: The study was reported based on the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. Literature was searched on PubMed, Embase, and Scopus following PRISMA guidelines. The search was conducted on October 12th, 2021, using the search term ("glue" OR "sealants" OR "tissue glue" OR "tissue sealant" OR "tissue adhesive") AND ("hypospadias" OR "urethrocutaneous fistula" OR "urethral repair" OR "urethroplasty" OR "hypospadiology"). Result: Systematic searching from all databases resulted in 160 potential articles. After a full-text review, eight articles were included in this study. UCF complication was reported in all studies. The occurrence of complication reported by all studies was urethrocutaneous fistula. Several studies also reported tissue edema and flap-related complications. Tissue sealant had no significant effect in reducing meatal stenosis. Conclusions: This systematic review revealed additional benefits from several types of tissue sealant in hypospadias repair surgery. Fibrin sealant application over the urethroplasty suture line in hypospadias repair offers a water-proof coverage and may enhance the outcome from the surgery.

Sealants for preventing dental caries in primary teeth.

Sealants for preventing dental caries in primary teeth.

Effect of Aging on the Microhardness of Different Resin-based Fluoride-releasing Fissure Sealants: An In Vitro Study

The aim of the present study was to evaluate the effect of aging on the microhardness score [Vickers hardness number (VHN)] of different resin-based fluoride-releasing sealants compared to non-fluoride resin-based sealants. A total of 48 extracted sound molars that were sectioned mesiodistally were used. In the current study, four types of sealants were compared: Group A, a resin-based non-fluoride-releasing pit and fissure sealant (Eco-S sealant) served as a control. Groups B, C, and D received resin-based fluoride-releasing pit and fissure sealants Helioseal F, Fissurit F, and Embrace™ WetBond, respectively. Subsequently, each group was further divided into immediate and aged subgroups. The samples had been evaluated regarding their microhardness using a pyramidal diamond indenter of a Vickers hardness test at two-time intervals: Immediately and after the aging process through thermocycling. There were no statistically significant differences between mean VHN and material types (p = 0.72). Aging appeared to significantly increase the mean VHN (p = 0.001). The interaction model between material type and time factor showed that the effect of aging differs by the material type, where the VHN of the Embrace™ group increased significantly after aging from 24.33 ± 5.60 to 31.70 ± 3.59 (p = 0.001). While there were no significant differences in the microhardness of commonly used fluoride-releasing fissure sealants, time appears to significantly increase the mean microhardness score (VHN), especially in the Embrace™ group. Embrace™ WetBond fissure sealant showed a significant improvement in the mean microhardness score (VHN) with time. However, clinical studies with long-term follow-up are needed to confirm our results.

Comparative Evaluation of Root Reinforcement Using MTA-based, Epoxy Resin-based, and Silicone-based Endodontic Sealers in Canals Instrumented with Single-file Rotary System: An In Vitro Study

To evaluate root reinforcement by four different sealers, namely, AH Plus, MTA Fillapex, Dia-ProSeal, and GuttaFlow 2, on endodontically treated teeth. Sixty human mandibular premolars were randomly divided into four groups of 15 teeth each, according to the type of sealer used: Group I AH Plus, Group II MTA Fillapex, Group III Dia-ProSeal, and Group IV GuttaFlow 2. All samples were decoronated to a length of 13 mm from the apex. Root canals were prepared by OneShape, 25/0.06 taper file and obturated with a matching single cone gutta percha (25/0.06) using the above-mentioned sealers. All samples were subjected to load by universal testing machine until a point at which root fractured, which was recorded. Teeth obturated with GuttaFlow 2 showed the maximum fracture resistance followed by AH Plus, Dia-ProSeal, and MTA Fillapex. There was no significant difference in fracture resistance between AH Plus and Dia-ProSeal. Teeth obturated with GuttaFlow 2 sealer, which has powdered gutta percha particles, showed the highest fracture resistance. According to the results obtained from this study, obturation of roots with GuttaFlow 2 increased the resistance of root canal-filled teeth to vertical root fracture.

Evaluation of microleakage of three different endodontic sealers in the presence and absence of moisture

Background and aims: AH26, Master-Dent, and Endoseal mineral trioxide aggregate (MTA) are three different types of sealers. The purpose of this study was to assess and compare THE apical seal of the root canal-treated teeth with the above-mentioned sealers in the presence and absence of moisture using the fluid filtration method. Methods: To this end, 54 freshly extracted single root canal human canines were selected for this study. The canals were prepared using rotary instruments, and then sodium hypochlorite was applied as an irrigation solution in this protocol. The specimens were randomly divided into three groups of 18. One group was obturated with the gutta-percha by the cold lateral compaction technique. Half of one of the aforementioned sealers belonged to the group of moistened teeth and the other half to the group of the dried teeth. Microleakage in all groups was assessed 3 months after the obturation of canals by the fluid filtration method. The data were analyzed using ANOVA and Tukey’s post hoc tests, and the level of significance was set at P<0.05. Results: The results showed that the minimum and maximum micro-leakage belonged to Masterdent dry (mean leakage = 1.7778 μL/ min/CmH20) and Endoseal-MTA dry (mean leakage = 3.5000 μL/min/CmH20), respectively. All three groups of sealers exhibited a significant difference in apical micro-leakage between dry and moist conditions (PMasterdent <0.001, PAH26=0.002, and PEndoseaL-MTA =0.007). Conclusion: The findings of this experimental study demonstrated that Masterdent provided the least apical micro-leakage under dry conditions while Endoseal-MTA had the highest micro-leakage under these conditions. There was a significant difference between dry and moist conditions in all groups.

TYPES OF PIT AND FISSURE SEALANTS. INDICATIONS AND CONTRAINDICATIONS FOR SILANIZATION. REVIEW

Background: Dental sealants have been used to reduce the incidence and severity of dental caries in the pits and fissures of teeth for over 40 years. Since that time, numerous scientific discoveries have led to the development of multiple generations of new sealant materials. Aim: The aim of this paper is to summarize the findings of reviews regarding the types of pit and fissure sealants, indications and contraindications for their use. Methods and materials: Previous systematic reviews on this topic were used as the basis for the current review. Cochrane, MEDLINE, Embase, and a few other bibliographic databases were searched for English and Bulgarian-language articles. The year of publication of the searched articles was limited from 2000 to 2020. Only articles in English and Bulgarian languages were read in full. Results: A total of 114 articles were identified by the literature search, the title and abstract of the articles were examined. Twenty-four original research studies met the inclusion criteria. They were read in full, and evidence was extracted for types of pit and fissure sealants, as well as indications and contraindications for their use. Conclusion: Evidence derived from the literature led to the conclusion that sealants are effective in preventing pit and fissure occlusal carious. The selection of the material used for silanization is made depending on a few factors that should be considered, such as patient's and tooth age, child's behavior and ability to isolate the surfaces which are going to be sealed. Regular examinations are required to be able to determine the need for reapplication of sealants and to maximize the effectiveness and results of the treatment.

Effect of two calcium-silicate sealers and a resin sealer on collagen matrix integrity of root dentin after different treatments. An in vitro and in vivo study

Introduction: This research aimed to examine and compare the effect of two calcium silicate sealers with AH plus resin sealer on collagen extraction and surface collagen degradation of dog's root dentin, using different irrigants.Materials and Methods: In vitro part; 180 standardized root dentin cylinders obtained from dog's incisors were randomly allocated into three groups (n = 60) according to the final irrigant used; Group A: 17% Ethylenediaminetetraacetic acid, Group B: 2.5% NaOCl, Group C: 0.9% saline. Each group was classified into 4 subgroups (n = 15) according to the type of sealer used for obturation; subgroup 1: BioRoot RCS, subgroup 2: Total Fill BC, subgroup 3: AH Plus sealer, and subgroup 4: Unfilled (control). After preparation, irrigation, obturation, and aging in a storage medium; hydroxyproline (HYP) released in the medium was determined after 1 day, 1 and 3 months using spectrophotometer. In vivo part, sixty incisors of five dogs were randomly allocated as in the vitro part into three groups and four subgroups in accordance to the type of irrigation and sealer used. After 3 months of preparation, irrigation, and obturation, dogs were euthanized and teeth were extracted for the assessment of surface collagen degradation using scanning electron microscope. HYP released was analyzed using repeated-measures analysis of variance and post hoc of Bonferroni. Surface collagen degradation was analyzed using Kruskal–Wallis test and Dunn's test.Results: BioRoot RCS and TotalFill BC showed a significant higher (P < 0.001) HYP release and surface collagen degradation than AH plus sealer and control with all irrigants.Conclusions: Calcium silicate sealers significantly affected the collagen microstructure of dentin surface. AH Plus resin sealer has no effect on collagen dissolution or microstructure.

Lack of Correlation Between the Penetration of Two Types of Sealers and Interfacial Adaptation to Root Dentine.

ObjectiveThis study aimed to determine the correlation between sealer penetration into dentinal tubules and interfacial adaptation to root canal walls using a hydraulic calcium silicate-based sealer, Endosequence Bioceramic Sealer (Brasseler USA, Savannah, GA, USA), and an epoxy resin-based sealer, AH Plus (Dentsply DeTrey, Konstanz, Germany).MethodsSixty-four maxillary central incisors were endodontically prepared with nickel-titanium rotary instruments and randomly assigned into two groups (n=32). Roots were filled with gutta-percha using a single-cone technique in conjunction with one of the two sealers, AHP or BCS. Sealers were mixed with Rhodamine B and analysed under a confocal laser scanning microscope. Transverse sections at 5 mm from root apex were obtained. The circumference of the root canal wall was first outlined and measured to determine the circumferential percentage of sealer penetration. The regions along the canal walls where the sealer had penetrated the dentinal tubules were delineated and measured. Then, the outlined distances were divided by the canal circumference. The width of each gap was measured and pooled for each specimen for comparison to determine the interfacial adaptation. The measurements were repeated twice to ensure reproducibility. Mann-Whitney tests were performed to compare continuous variables between AHP and BCS groups. The correlation between gap width and percentage of sealer penetration was investigated using the Spearman correlation coefficient.ResultsNo significant difference was observed between groups regarding the percentage of sealer penetration (P>0.05) and the gap width (P>0.05). Also, there was no significant correlation between the two variables analysed for AHP (r=0.165; P>0.05) and BCS (r=-0.147; P>0.05) and in the overall sample (r=0.061; P>0.05).ConclusionThe present results show no correlation between interfacial adaptation and sealer penetration in dentinal tubules in the total sample and among sealer subgroups. The ability of root canal sealers to penetrate dentinal tubules cannot be considered a sign of better interfacial adaptation.

Dissolving efficacy of xylene on epoxy resin-based and bioceramic-based root canal sealers

Background: Epoxy resin-based and bioceramic-based root canal sealers are used in endodontic treatment as root canal obturation materials because they are considered to have many advantages. The complete removal of these materials during root canal retreatment is crucial in order to ensure adequate disinfection. Due to the difficulty in accessing root canal ramifications, removal of these filling materials without damaging the teeth can be successfully achieved using endodontic solvents. Objective: The aim of this study was to evaluate the solubility of two types of root canal sealers in xylene used in endodontics. Methods: A total of 34 epoxy resin and bioceramic samples were stored for 72 h in an incubator to set. The samples were then immersed for 2 min in 1 mL of xylene. The excess xylene on the samples was drained with an absorbent paper and stored in an incubator for 24 h to dry. The pre- and post-immersion weight of the samples was measured using a digital analytical scale, then the weight difference between the groups was analyzed using the independent t test at a 5% significance level. Results: No significant difference was observed between the epoxy resin-based root canal sealer group and the bioceramic-based root canal sealer group (P ≥ 0.05). Conclusion: Xylene endodontic solvent has a similar efficacy for removing epoxy resin-based and bioceramic-based root canal sealers in in vitro study.

Cytotoxicity and biocompatibility of root canal sealers: A review on recent studies

Many types of endodontic root canal sealers have been employed for the purpose of filling voids and irregularities in root canals, as well as reducing/removing bacterial remnants/remains. Sealers are available in various formulations, and research work to find the most appropriate ones is still ongoing. Recently, many kinds of novel root canal sealers have been introduced under various commercial names. However, most sealers are known to exhibit different levels of cytotoxicity on tissues which would result in prolonged wound healing, inflammation, and bone resorption. Preferably, sealers need to have tolerable biological and physico-chemical properties along with biocompatibility. Additives promoting the biocompatibility and bioactivity of sealers are of major concern in clinical applications. The aim of this review was to compare, evaluate, and analyze comparatively the cytotoxic effects, biocompatibility, and antimicrobial properties of recently used root canal sealers. A comprehensive literature search was made to identify their properties involving biocompatibility and cytotoxicity. In general, the sealers reported in recent literature exhibited favorable biological features in comparison to conventional ones. They promoted better cell viability and biocompatibility. The incorporation of additives influences favorably the potential negative effects. However, it has been highlighted that there is a lack of well-designed long-term clinical applications, and more in vitro and in vivo research work would be helpful to confirm the sustainability of the sealers for further clinical practice.

Evaluation of In situ Adaptability of Two Types of Fissure Sealants Placed with or Without Enameloplasty

Context: Literature has no consensus over the utility of enameloplasty before fissure sealant placement. Aim: The objective of the study was to explore the effect of enameloplasty using a scanned electron microscope on the adaptability of resin-modified glass ionomer versus flowable resin-based sealants. Settings and Design: An in vitro, experimental study was done from July to November 2017 at the NED University and Dow University of Health Sciences, Karachi, Pakistan. Materials and Methods: An in vitro experimental study was done, for which twenty extracted human molars and premolars were selected. They were divided into two groups on the basis of sealant type (resin-modified glass ionomer versus flowable resin-based sealant). The groups were further subdivided on the basis whether these were subjected to enameloplasty or not. All specimens were thermocycled, sectioned, dried, and gold sputtered before inspection under a scanning electron microscope (×50). Statistical Analysis Used: The adaptability of the sealant material in the tooth fissures was assessed on an ordinal scale. SPSS version 23.0 was used for data analysis. Mann–Whitney U-test and ordinal regression were applied at 0.05 level of significance. Results: There were no statistically significant differences between adaptability scores achieved with resin-modified glass ionomer-based sealant and flowable resin-based sealant (P = 0.96). Moreover, enameloplasty resulted in inferior adaptability of the two sealant materials (P = 0.02). Conclusions: Enameloplasty has shown to exert a negative influence over adaptation of the sealant material into the tooth fissure irrespective of the sealant chemistry.

Comparative evaluation of radiographic density of different endodontic material

The purpose of this study was to evaluate and compare the densities of four different brands of root canal sealers using three different intraoral imaging receptors. Four different root canal sealers used were – AH Plus (Dentsply Germany, Resin based), Epiphany (Pentron USA, Resin based), U/P (Sultan Healthcare, Zinc oxide eugenol based) and Apexit (Ivoclar / Vivadent, Calcium hydroxide based). The sealers were mixed according to manufacturer instructions and six specimens of each material were fabricated. All the specimens were imaged using three different intraoral #2 sized imaging receptors-D and E speed film and storage phosphor plates. D and E speed films were digitized and stored in JPEG format. All the images were exported into the Image J software (rsb.info.nih.gov/ij/) and the mean grey values and integrated density of each material was calculated from four random areas of each image and averaged. Mixed model ANOVA was performed. Pair wise comparison of mean grey values between the three imaging receptors and integral densities recorded by the receptors showed high statistical significance for all the four different root canal sealers. Results showed that the four different types of root canal sealers showed different optical densities on all the three receptors. The purpose of this study is to evaluate and compare the optical densities of four different brands of root canal sealers using three different intraoral imaging receptors.

An in vitro study on the effects of serum proteins on Enterococcus faecalis adhesion to three types of root sealers and gutta-percha

BackgroundThe extrusion of overfilled materials that extend beyond the apical foramina into the periradicular tissue may serve as a reservoir for bacterial adhesion and further affect recovery from periapical diseases. The aim of this study was to evaluate the effects of serum proteins on Enterococcus faecalis adhesion and survival on the surface of a calcium hydroxide-based root canal sealer (Apexit Plus), an epoxy resin sealer (AH-Plus) and a bioceramic sealer (iRoot SP).MethodsApexit Plus, AH-Plus and iRoot SP were evenly coated on gutta-percha, using gutta-percha alone as the control. After root canal sealer setting, the number of E. faecalis adhering to the root canal sealers and gutta-percha was counted in fetal bovine serum (FBS) or tryptic soy broth supplemented with 1% glucose (TSBG) by viable cell plate counts. The morphology of 7-day-old E. faecalis biofilms in FSB and TSBG was observed by scanning electron microscopy (SEM). Furthermore, E. faecalis biofilms on the three root canal sealers were labeled with a LIVE/DEAD BacLight™ Bacterial Viability Kit, and the ratios of viable to dead cells were analyzed using laser scanning microscopy operative software (Zen software).ResultsIn the assays, after 1 and 7 days, the number of E. faecalis adhering to the root canal sealers or gutta-percha in FBS were significantly lower than those in TSBG (P < 0.05). In FBS, E. faecalis adhesion to iRoot SP and gutta-percha was reduced to a greater extent than that adhered to Apexit Plus and AH-Plus. Few E. faecalis accumulated on iRoot SP in FBS, whereas many bacteria assembled on iRoot SP and formed biofilms in TSBG. The ratio of viable cells in the E. faecalis biofilm on iRoot SP was the lowest.ConclusionsCalcium hydroxide-based root canal sealers, epoxy resin sealers and bioceramic sealers may provide a substrate for E. faecalis adhesion, and the bioceramic sealer in this study showed the least E. faecalis adhesion in the presence of serum proteins compared to the other two sealers.

The Effect of Resin-Based Dental Sealant Containing Vanillin on Biofilm Formation of &lt;i&gt;Candida albicans&lt;/i&gt;

Early childhood caries (ECC), or baby bottle tooth decay is one of the most common chronic diseases that affect young children at 6 years of age or younger. The disease is resulted from complex interactions between tooth structures and cariogenic microorganisms in dental biofilm after exposure to fermentable carbohydrates through improper feeding practices. This leads to a rapid development of demineralization of teeth shortly after they erupt in the oral cavity. Candida albicans have been reported recently to be associated with the pathogenesis of ECC. One of the general approaches currently used for the prevention of ECC is the application of dental sealant to occlusal (chewing surface) pits and fissures of caries-susceptible teeth. Many types of dental sealants have been extensively used and various antimicrobial agents were introduced to dental sealants to increase their caries preventive effect. The aim of the present study was to evaluate the antimicrobial effect of vanillin incorporated resin-based dental sealant on C. albicans biofilm. Resin-based dental sealants (Clinpro; 3M ESPE, USA) containing different concentrations of vanillin (0%, 0.5%, 1% and 5% w/v) were prepared in 96-well plate. The suspension (107 colony forming unit/mL) of each strain of Candida albicans (ATCC 10231, ATCC 18804 and 2 clinical isolates) was added to saliva-coated sealant resin samples and incubated at 37°C in 5% CO2 atmosphere for 24 h to allow the Candida biofilm formation. The quantity of vital biofilm was determined by WST Microbial Cell Counting Kit (Dojindo Molecular Technologies, USA) at 460 nm. All tests were done in triplicate and repeated three times. Kruskal-Wallis test followed by Dunn’s method were used to account for multiple comparisons. Statistical significance was set at p-value less than 0.05. The results showed that 0.5-5% vanillin-incorporated dental sealant resins showed a significant suppressive effect against all strains of Candida. No significant differences of anti-biofilm effects were found among Candida strains. Approximately 30-50% Candida biofilm reduction was noticed in sealant resins containing vanillin compared with controls without vanillin. In conclusion, the adding of vanillin (0.5-5% w/v) to dental sealant resins is effective in inhibiting biofilm formation of fungus related to early childhood caries, C. albicans. Therefore, the use of dental sealants containing vanillin has the potential to prevent this type of dental caries in young children and biofilm formation by oral Candida. Further clinical studies are required to investigate physical properties of this sealant and clinical evaluation in the patients.

The Effect of Softening of Gutta-Percha Using Cajuput Oil in Root Canal Filling with Epoxy Resin and Glass Ionomer Cements Sealers

Background: The failure of root canal treatment is non-hermetic obturation. It could be prevented with the use of sealer material. The sealer with an excellent bond to the dentin is epoxy resin and glass ionomer cement sealer. Eucalyptus oil is a natural substance that could dissolve gutta-percha because it has an antimicrobial effect and is biocompatible. Objective: To determine the effect of softening with Cajuput Oil on root canal filling with epoxy resin and glass ionomer cement sealers. Methods: The design of this study was pure laboratory experimental, 24 samples of single root canal block, each block was prepared with step back technique and obturation with lateral condensation. The samples were treated differently by the type of sealer used and incubation time. Group of treatment will be dripped with 0.1 ml of cajuput oil for 5 minutes. Compressive loading was performed apico-coronally by Universal testing machine using cylindrical stainless-steel plunger speed of 2 mm/min until softening occurred. The data were processed using a one-way ANOVA and Post-Hoc Tukey test with a significance level of 95% (p &lt;0,05). Results: There was a significant effect of epoxy bisphenol resin sealer and Glass Ionomer Cement sealer in softening gutta-percha using cajuput oil. The epoxy resin sealer, which was incubated for 22 days after contact with cajuput oil for 5 minutes, had a higher softening value than others. Conclusion: Sealer epoxy bisphenol resin is easier to remove than the Glass Ionomer Cement sealer with cajuput oil solvent at 22 days after incubation.

Effect of Different Treatment Regimen and Types of Endodontic Sealers on Pain and Periapical Radiographic Changes

INTRODUCTION: The study aims as a pilot study to evaluate the effect of different treatment regimen and different types of endodontic sealers on pain and periapical radiographic changes was studied. MATERIALS AND METHODS: Forty patients in need of an endodontic root canal treatment on anterior teeth were selected and divided into two groups (20 patients each), according to the endodontic treatment protocol (single or multiple visits). Then, each group was subdivided into two subgroups according to sealer used 10 each (AH Plus Jet resin sealer, Total Fill Bioceramic Sealer). To record pain intensity of the patients at different intervals: 1, 2, 3, 7 days, a visual analog scale was used. Furthermore, patients were recalled after 1, 3, 6, 9 months to evaluate periapical radiographic changes. RESULTS: Showed that as regard pain assessment both tested endodontic sealers, as well as single or multiple visits have no statistically significant difference between pain values of patients during all the observation period from immediately post-operative, after 4, 12, 24, 48, 72 h as well as after 7 days (p &gt; 0.05). As regard lamina dura thickness, results showed that with both tested endodontic sealers as well as single or multiple visits, there was no statistically significant difference between lamina dura thickness of patients after 1 month, 3, 6 as well as after 9 months. CONCLUSIONS: Neither number of visits of endodontic treatment nor type of sealer used for obturation affects post-operative pain and thickness of lamina dura.

Sealing Ability of Various Types of Root Canal Sealers at Different Levels of Remaining Gutta Percha After Post Space Preparation at Two Time Intervals.

ABSTRACTObjective:This study evaluated the apical sealing ability of various types of sealers (Sure-Seal Root, AH Plus, and GuttaFlow2) at different levels of remaining gutta percha after post space preparation at two time intervals (1 day and 1 week after obturation).Materials and Methods:One hundred and two single canal mandibular premolars were decoronated at the cement–enamel junction and biomechanically prepared. Twelve samples served as negative and positive controls (n = 6). The remaining 90 samples were distributed into three groups (n = 30 each), based on the used sealer for obturation with gutta percha (Sure-Seal Root, AH Plus, GuttaFlow2). Each experimental group was divided into two subgroups (n = 15 each), subgroup I: post space prepared 1 day after obturation and subgroup II: post space prepared 1 week after obturation. For each subgroup, the post space was prepared to a length that remained 3, 4, or 5 mm of gutta percha apically for each of five samples. Then, the dye penetration technique was used to measure the apical microleakage. Data were analyzed using “ANOVA test” and “post hoc Duncan’s test.”Results:Sure-Seal Root sealer demonstrated the best apical seal compared with other tested sealers. Post space preparation 1 day after obturation exhibited less microleakage than the group with 1 week after obturation. Additionally, 5 mm of remaining gutta percha showed superior sealing value than 3 and 4 mm.Conclusion:Bioceramic (Sure-Seal) sealer is the material of choice to be used when post space preparation is required. Post space preparation was preferred to be done 1 day after obturation than 1 week after obturation. Superlative apical seal was obtained with a maximum length of remaining gutta percha.

Properties of Sealed Joints After Exposure to Water

In practice, sealed joints in the construction industry are very often exposed to adverse climatic influences. One of these climatic influences is the effect of water, for example in the form of rain or humidity. This article is therefore devoted to the sealing of joints of problematic base materials, which are then exposed to the effects of water and subsequently tested according to the recommended test standards. For this research, a problematic substrate based on cement is selected, and glass cement is specifically chosen for its shortcomings. The main disadvantage of this material is the existence of small particles on its surface, which due to their insufficient wettability disrupt the adhesion of both the primer and subsequently the sealant to this substrate and thus significantly reduce the quality of the sealed joint. Furthermore, representatives of several types of sealants and primers recommended for them available on the Czech market are selected for this experiment. Test specimens are made using glass cement plates treated with the appropriate primer and the sealant. These test specimens are then the goal of a test procedure to verify the properties of the sealed joint of the problematic material and the selected primer and sealant that is exposed to the water element. The results of these tests are then presented in the article.

Research on fracture behaviour of the adhesive sealant based on energy failure criterion for TFT-LCD

The adhesive sealant is a crucial structure connecting color filters and thin film transistors in liquid crystal panels. Research on the fracture progress of the connection structure is heavily needed in reliability evaluation engineering. In this work, three types of adhesive sealants with different widths were tested by the uniaxial tensile experiment to obtain their fracture process curves, which conformed to the brittle fracture characteristics described by the bilinear cohesion zone model. Then, according to the theory of engineering fracture mechanics, the Dugdale-Barenblatt plastic zone model was employed to analyze the adhesive sealant with hole defects, and it was simplified to mode ? fracture mechanics problem. Calculating with finite element numerical simulation, the numerical relationship between the stress field of the internal defect and the external stress of the material was obtained, and the brittle fracture behavior model was deduced as related to the defect size. Applying the model to the adhesive sealant, the average error of the model value after the correction was reduced from 7.98-12.13% to 6.84-7.53%, and the overall error was only within 15%. The model includes the material’s basic characteristics and the defect’s size that affect the fracture process, provides a theoretical basis for predicting the fracture of the sealant and improving the strength of bonded joints, thus is of great significance for material application and fracture analysis in engineering.