Root Canal Adhesive Filling in Dogs’ Teeth with or without Coronal Restoration: A Histopathological Evaluation

Biological considerations of dental materials as orifice barriers for restoring root-filled teeth

There is ample published literature regarding the technical aspects of restoring root-filled teeth, but little concerning the biological impacts, consequences, and criteria for the selection of direct restorative materials following endodontic treatment. The provision of an effective coronal seal in addition to a sound root filling is known to be important in the prevention of root canal infection. This review seeks to explore the evidence concerning the selection of dental materials in the restoration of root-filled teeth, specifically with a close examination of the properties of commonly used materials as orifice barriers. © 2023 Australian Dental Association.

Expression of Toll-like receptor 2, Dectin-1, and Osteopontin in murine model of pulpitis

OBJECTIVES

This in vivo animal study aimed to develop a murine model of pulpitis induced by pulp exposure with or without application of zymosan in Naval Medical Research Institute (NMRI) mice and observe expressions of Toll-like receptor (TLR)-2, TLR-4, Dectin-1, Osteopontin (OPN), tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, and IL-1ß.

MATERIAL AND METHODS

A total of 168 NMRI mice were divided into two groups, i.e., group A (n = 84) (pulpitis induced by pulp exposure only) and group B (n = 84) (pulpitis induced by pulp exposure and zymosan application). Right maxillary molar pulps were exposed with ¼ round bur, and animals were sacrificed at 0, 6, 9, 12, 24, 48, and 72 h. The exposed teeth were obtained for real-time polymerase chain reaction (qRT-PCR) analysis and histological and immunohistochemistry (IHC) analysis.

RESULTS

Histological evaluation revealed a time-dependent steady increase in inflammation. Similar time-dependent increase in the expression of inflammatory cytokines was noted. Group A exhibited an increase in TLR-4, Dectin-1, and OPN at 6 h, while TLR-2 was expressed at 24 h. Group B expressed TLR-2, Dectin-1, and OPN at 9, 48, and 72 h, respectively (p ≤ 0.05). Expression of OPN and TNF-α exhibited a similar pattern in both groups. IHC also detected expression of TLR-2, Dectin-1, TLR4, and CD68 in some cells at 6 and 9 h.

CONCLUSIONS

NMRI mice provided for a stable pulp inflammation model. Zymosan may be used to develop pulp inflammation model and study inflammatory response towards fungal antigens. Dental pulp expressed Dectin-1 receptor. OPN and TNF-α exhibited a similar expression pattern.

CLINICAL RELEVANCE

Innate immunity of dental pulp is capable of detecting fungal pathogens.

What Are the Chances of Resilon to Dominate the Market Filling Materials for Endodontics?

This paper is a literature review with additional virtual analyses of the authors’ own experimental research results. Knowledge from various areas was synergistically combined, appropriately for concurrent engineering, presenting several possible methodological approaches used in research, optimizing the selection of engineering materials and the conditions of their application with particular application in endodontics. Particular attention was paid to the theoretical aspects of filling material strengths, weaknesses, opportunities, and threats SWOT analysis. Attention was paid to the original concepts of Sustainable Dentistry Development in conjunction with Dentistry 4.0, which includes endodontics as an important element. The dentists’ actions, among others, in conservative dentistry, along with endodontics, requires close cooperation with engineers and the enginering sciences. Methods of root canal preparation were described, together with selected tools, including those made of nitinol. Principles concerning the process of cleaning and shaping the pulp complex are presented. The importance of obturation methods, including the Thermo-Hydraulic-Condensation THC technique, and the selection of filling materials with the necessary sealants for the success of endodontic treatment are discussed. The experimental studies were carried out in vitro on human teeth removed for medical reasons, except for caries, for which two groups of 16 teeth were separated. After the root canal was prepared, it was filled with studs and pellets of a filling material based on polyester materials, which has gained the common trade name of resilon or, less frequently, RealSeal (SybronEndo) with an epiphany sealant. The teeth for the first group were obturated by cold lateral condensation. In the second case the obturation was performed using the Thermo-Hydraulic-Condensation technique using System B and Obtura III. The experimental leakage testing was done using a scanning electron microscope SEM and a light stereoscopic microscope LSM, as typical research tools used in materialography. The research results, in a confrontation with the data taken from the literature studies, do not indicate the domination of resilon in endodontics.

Virtual Approach to the Comparative Analysis of Biomaterials Used in Endodontic Treatment

The importance of endodontics is presented within our own concept of Dentistry Sustainable Development (DSD) consisting of three inseparable elements; i.e., Advanced Interventionist Dentistry 4.0 (AID 4.0), Global Dental Prevention (GDP), and the Dentistry Safety System (DSS) as a polemic, with the hypothesis of the need to abandon interventionist dentistry in favour of the domination of dental prevention. In view of the numerous systemic complications of caries that affect 3−5 billion people globally, endodontic treatment effectively counteracts them. Regardless of this, the prevention of oral diseases should be developed very widely, and in many countries dental care should reach the poorest sections of society. The materials and methods of clinical management in endodontic procedures are characterized. The progress in the field of filling materials and techniques for the development and obturation of root canals is presented. The endodontics market is forecast to reach USD 2.1 billion in 2026, with a CAGR of 4.1%. The most widely used and recognized material for filling root canals is gutta-percha, recognized as the “gold standard”. An alternative is a synthetic thermoplastic filler material based on polyester materials, known mainly under the trade name Resilon. There are still sceptical opinions about the need to replace gutta-percha with this synthetic material, and many dentists still believe that this material cannot compete with gutta-percha. The results of studies carried out so far do not allow for the formulation of a substantively and ethically unambiguous view that gutta-percha should be replaced with another material. There is still insufficient clinical evidence to formulate firm opinions in this regard. In essence, materials and technologies used in endodontics do not differ from other groups of materials, which justifies using material engineering methodology for their research. Therefore, a detailed methodological approach is presented to objectify the assessment of endodontic treatment. Theoretical analysis was carried out using the methods of procedural benchmarking and comparative analysis with the use of contextual matrices to virtually optimize the selection of materials, techniques for the development and obturation of root canals, and methods for assessing the effectiveness of filling, which methods are usually used, e.g., in management science, and especially in foresight research as part of knowledge management. The results of these analyses are presented in the form of appropriate context matrices. The full usefulness of the research on the effectiveness and tightness of root canal filling using scanning electron microscopy is indicated. The analysis results are a practical application of the so-called “digital twins” approach concerning the virtual comparative analysis of biomaterials used in endodontic treatment.

Accuracy of Conventional Periapical Radiography in Diagnosing Furcation Repair after Perforation Treatment

INTRODUCTION

Periapical radiography (PR) is a diagnostic tool to be used by professionals in clinical practice. The method presents limitations, and doubts still exist about its value to evaluate furcation perforation and the reparative process of hard or soft tissues after treatment. Thus, the aim of this study was to evaluate the accuracy of PR as a diagnostic method to detect both resorption of the furcation area after induced experimental perforation and repair after perforation treatment using histopathological findings as a gold standard.

METHODS

Thirty teeth of beagle dogs with furcation perforation were filled with Biodentine (Septodont, Saint-Maur-des-Fossés, France), ProRoot White mineral trioxide aggregate (Dentsply Tulsa Dental Specialties, Tulsa, OK), or gutta-percha and examined using PR and histology. Sensitivity, specificity, predictive values, and accuracy were calculated.

RESULTS

PR detected repair and reabsorption of furcation perforation in 55% and 48% of the teeth, respectively. Histologic analysis showed furcation perforation in 66% and 21% of the teeth, respectively. Sensitivity and specificity of PR for the detection of repair were 0.84 and 1, respectively, whereas for resorption detection, the values were 0.43 and 0.65, respectively. Diagnostic accuracy for PR was 0.89 and 0.72 for repair and resorption of furcation perforation, respectively. PR showed more accurate diagnostic (true positives + true negatives/total) in repair detection compared with resorption of furcation perforation.

CONCLUSIONS

We conclude that PR is not adequate in detecting resorption progress after the treatment of furcation perforation, and we encourage the use of digital imaging when suspicious of a possible unsuccessful result after furcation perforation treatment.

The effect of vitality and dentin depth on resin tags length of resin-dentin interface in dogs' teeth

The aim of this study was to evaluate the effect of pulpal pressure and dentin depth on the quality of hybrid layer of bonded composite. Four healthy dogs, aged between 12 and 18 months, with intact dentitions were used for the experimental work. A total of 24 teeth were available for the study by using the six upper anterior teeth of each of the four dogs used in the study. The 24 teeth included in the study were divided according to presence or absence of pulpal pressure (P) into two groups with 12 teeth in each group. P₁ teeth with positive pulpal pressure and P₂ teeth with no pulpal pressure. Each of these two groups was further divided into two subgroups, according to the cavity depth (D) they received, where in D₁ a class V cavity with depth of 1 mm was performed, while in D₂ a class V cavity with depth of 2 mm was performed. The cavities were restored with micro hybrid composite restorative material and the samples were then left in the dogs’ mouth for 30 days. At the end of the experimental period, the dogs were euthanized by injecting an overdose of thiopental sodium. The anterior part of the upper jaw was sawed out of each dog’s mouth and the teeth were sectioned to evaluate the resin–dentin interface using Environmental Scanning Electronic Microscope. Results of the study showed that the mean resin tag length value was significantly affected by vitality and dentin depth. The presence of pulpal pressure together with depth of dentin could adversely affect the quality of hybridization.

Pulpal Tissue Inflammatory Reactions after Experimental Pulpal Exposure in Mice

INTRODUCTION

The purpose of this study was to establish a stable experimental mice pulpal inflammatory model and to evaluate inflammatory reactions of pulpal tissue after pulpal exposure.

METHODS

Pulpal inflammation was induced in 80 C57BL/6 mice by occlusal exposure of the pulp of the maxillary first molar. The mice were sacrificed randomly at 0, 1, 6, 12, 24, 48, and 72 hours after pulpal exposure. Mice without pulpal exposure served as controls. Maxillary teeth were obtained and prepared for histologic analyses and real-time polymerase chain reaction analyses.

RESULTS

As the duration of pulpal exposure increases, the inflammatory reaction is exacerbated. Within 6 to 12 hours after pulpal exposure, pulp tissues experienced red blood cell extravasation to the destruction of the odontoblast layer. After 24 hours, necrosis was observed in the pulpal tissue; until 72 hours, necrosis spread to the whole coronal pulpal tissue, and a large number of inflammatory cells were found in the radicular pulpal tissue. The results of histomorphologic scores have the same trend; samples from the 72-hour group possessed the highest score followed by samples from other groups (P < .01). The expression levels of inflammatory cytokines increased over the 72 hours, and there was a high rate of inflammatory cytokine expression at 6 and 12 hours after pulpal exposure.

CONCLUSIONS

Our study represents a stable mice model for studying pulpal inflammation in vivo. Mouse pupal inflammation progresses rapidly, with dramatic changes evident in just a few hours.

Resilon: Review of a New Material for Obturation of the Canal

Resilon is a thermoplastic synthetic polymer-based endodontic material alternative to gutta-percha. It contains bioactive glass and also radiopaque fillers. It has the same handling properties as gutta-percha. For endodontic retreatment, it may be dissolved with some solvents, such as chloroform or softened with heat. The composition of Resilon and its sealer (Epiphany) bond to dentin and form a monoblock. A review of the literature and a discussion of its properties comparing to other root canal filling materials are presented.

Ability of new obturation materials to improve the seal of the root canal system: a review

New obturation biomaterials have been introduced over the past decade to improve the seal of the root canal system. However, it is not clear whether they have really produced a three-dimensional impervious seal that is important for reducing diseases associated with root canal treatment. A review of the literature was performed to identify models that have been employed for evaluating the seal of the root canal system. In vitro and in vivo models are not totally adept at quantifying the seal of root canals obturated with classic materials. Thus, one has to resort to clinical outcomes to examine whether there are real benefits associated with the use of recently introduced materials for obturating root canals. However, there is no simple answer because endodontic treatment outcomes are influenced by a host of other predictors that are more likely to take precedence over the influence of obturation materials. From the perspective of clinical performance, classic root filling materials have stood the test of time. Because many of the recently introduced materials are so new, there is not enough evidence yet to support their ability to improve clinical performance. This emphasizes the need to translate anecdotal information into clinically relevant research data on new biomaterials.

Periapical inflammation subsequent to coronal inoculation of dog teeth root filled with resilon/epiphany in 1 or 2 treatment sessions with chlorhexidine medication

INTRODUCTION

Therapeutic methods that inhibit microbial ingress into filled root canals are desirable. This in vivo study assessed the inhibition of periapical inflammation subsequent to coronal inoculation in canals medicated with 2% chlorhexidine gel and filled with Resilon/Epiphany (Pentron Clinical Technologies, Wallingford, CT).

METHODS

Six Beagle dogs each had 10 two-rooted premolars treated. In group 1 (n = 36 roots), 1 root/tooth had the canal conditioned with Primer Epiphany, filled with Epiphany sealer and Resilon core in 1 session, and coronally sealed with PhotacFil. In group 2 (n = 36 roots), the second root/tooth had the canal medicated with 2% chlorhexidine gel for 1 week and then filled and coronally sealed as in group 1. After 3 weeks, canals were exposed to the oral environment for 7 days, inoculated with isologous plaque, and coronally sealed. Negative controls treated as groups 1 and 2 remained sealed. Positive controls had canals unfilled and exposed. Seven months after inoculation, dogs were euthanized; jaw blocks processed for histologic examination; and periapical inflammation (PI) recorded as none, mild, or severe.

RESULTS

In groups 1 and 2, severe PI occurred in 5 of 65 roots (8%) and mild PI in 18 of 65 roots (28%) with a significantly higher (P = .031) PI incidence in group 2 than in group 1. Negative controls had only mild PI in 9 of 29 roots (31%). Roots medicated with 2% chlorhexidine gel had mild PI significantly more (P = .009) than roots filled in 1 session (more than 2-fold).

CONCLUSIONS

Intracanal medication with 2% chlorhexidine gel and root filling with Resilon/Epiphany did not effectively inhibit apical periodontitis subsequent to coronal inoculation.

Resilon: a comprehensive literature review

Background and aims. An ideal root canal filling material should completely seal the entire root canal space and block communication between the root canal system and its surrounding tissues; it should also be nontoxic, noncarcinogenic, non-genotoxic, biocompatible, insoluble in tissue fluids and dimensionally stable. Bonding to dentin is a promising property, which can prevent leakage and improve the sealing ability of root canal filling materials. Resilon was developed and rec-ommended initially because the existing rootcanal filling materials did not bond to root canal dentin. Since its introduction in 2004, numerous reports have been published regarding various aspects of this material. The aim of this literature review is to present investigations regarding Resilon's physical and chemical properties and leakage studies. Materials and methods. A review of the literature was performed by using electronic and hand searching methods for Resilon from May 2004 to April 2012. Results. There are many published reports regarding Resilon. The searchshowed that Resilon is composed of a parent polymer, polycaprolactone or Tone, which is a biodegradable aliphatic polyester, with filler particles consisting of bioactive glass, bismuth oxychloride and barium sulfate. It possesses some antibacterial and antifungal properties. It is a promising material for root canal filling. Despite the presence of numerous case reports and case series regarding these applications, there are few designed research studies on clinical applications of this material. Resilon has some drawbacks such as high cost. Conclusion. Resilon seals well and is a biocompatible material. However, more clinical studies are needed to confirm its efficacy compared with other materials.

Qualitative SEM/EDS analysis of microleakage and apical gap formation of adhesive root-filling materials

Objective

The aim of this study was to compare the correspondence between gap formation and apical microleakage in root canals filled with epoxy resin-based (AH Plus) combined or not with resinous primer or with a dimethacrylate-based root canal sealer (Epiphany).

Material and Methods

Thirty-nine lower single-rooted human premolars were filled by the lateral condensation technique (LC) and immersed in a 50-wt% aqueous silver nitrate solution at 37ºC (24 h). After longitudinal sectioning, epoxy resin replicas were made from the tooth specimens. Both the replicas and the specimens were prepared for scanning electron microscopy (SEM). The gaps were observed in the replicas. Apical microleakage was detected in the specimens by SEM/energy dispersive spectroscopy (SEM/EDS). The data were analyzed statistically using an Ordinal Logistic Regression model and Analysis of Correspondence (α=0.05).

Results

Epiphany presented more regions containing gaps between dentin and sealer (p<0.05). There was correspondence between the presence of gaps and microleakage (p<0.05). Microleakage was similar among the root-filling materials (p>0.05).

Conclusions

The resinous primer did not improve the sealing ability of AH Plus sealer and the presence of gaps had an effect on apical microleakage for all materials.

Evaluation of bacterial microleakage of root canals irrigated with different irrigation solutions and KTP laser system

OBJECTIVE

The aim of this study was to evaluate bacterial microleakage of the root canals irrigated with different irrigation solutions and the potassium-titanyl-phosphate (KTP) laser system and filled with gutta-percha and AH26 root canal sealer. In addition, the effect of the irrigation solutions on dentin surface was evaluated with a scanning electron microscope (SEM).

BACKGROUND DATA

A few studies have reported that KTP laser has the capacity to remove the smear layer. Many researchers have demonstrated that propolis has a bactericidal effect. Both are important effects on root canal treatments.

MATERIALS AND METHODS

One hundred and twenty single-root single-canal mandibular premolar teeth were used for this study. The root canals were prepared by Dentaport Root ZX and ProTaper rotary instruments with the crown-down technique. The specimens were randomly divided into five groups of 20 teeth each. Each group was irrigated with 17% ethylenediaminetetraacetic acid (EDTA), 20% propolis, 2.5% sodium hypochlorite (NaOCl), 2% chlorhexidine gluconate (CHX), and KTP laser, respectively. A total of 20 teeth were used as controls-10 positive controls and 10 negative controls-which were irrigated with distilled water. The root canals were filled with gutta-percha and AH-26. The external surfaces of specimens were covered with three layers of nail varnish except the apical third. The teeth were inserted into Eppendorf plastic tubes and suspended in glass bottles containing sterile broth. All specimens were inoculated every 5 days with Enterococcus faecalis. The contamination onset time was continuously recorded, as turbidity was the first indication of contamination in a period of 30 days.

RESULTS

All statistical analysis was performed using the SPSS for Windows version 15.0 software. A χ(2) test was computed and the statistical significance was set at p<0.05. The controls behaved as expected.

CONCLUSIONS

This study showed that different irrigation solutions and KTP laser allowed microleakage of E. faecalis.

Comparative Resistance of AH26 and a New Sealer Prototype to a Bacterial Challenge

Objective. This study compared the leakage resistance of a New Sealer Prototype (NSP) with a traditional sealer (AH 26) in Resilon-filled roots subjected to a bacterial challenge. Study Design. 41 roots were instrumented to ISO size 50 apically. Group 1 (n = 20) contained Resilon and AH 26 sealer and roots in group 2 (n = 21) contained Resilon and NSP. Roots were embedded in a dual-chamber model with the upper chamber containing Streptococcus mutans inoculum. Evidence of bacterial penetration was observed for 1 month. Fisher's Test was used to analyze the data. Results. 8 of 20 roots (40%) in the AH 26 group demonstrated leakage whereas 3 of 21 roots (14%) in the NSP group leaked. The difference in leakage rates was not statistically significant (P = 0.053). Conclusion. The traditional sealer (AH 26) demonstrated increased leakage rates compared to the New Sealer Prototype (NSP), but the difference did not reach statistical significance in this study.

Biocompatibility of RealSeal, its primer and AH Plus implanted in subcutaneous connective tissue of rats

OBJECTIVE

This study tested rat connective tissue response to RealSeal, RealSeal primer or AH Plus after 7, 15, 30, 60 and 90 days of implantation.

MATERIAL AND METHODS

Thirty Wistar rats had subcutaneous sockets created on their back and received four implants each of polyethylene tubes containing one of the materials tested according to the groups: AH (AH Plus Sealer); RS (RealSeal Sealer); RP (RealSeal Primer); CG (control group - empty tube). After histological processing, sections were analyzed to identify the presence of neutrophils, lymphocytes and plasma cells, eosinophils, macrophages and giant cells, as well as fibrous capsule and abscesses, by an examiner using light microscope. Kruskal-Wallis and multiple-comparisons test were used for statistical analysis. Significance level was set at 5%.

RESULTS

Lymphoplasmacytic infiltrate scores significantly higher than those of the control group were observed at 14 and 60 days in AH group, and at 90 days in RS group (p<0.05). There were no differences in terms of presence of macrophages, giant cells, eosinophils, neutrophils or fibrosis. AH Plus group scored higher for abscesses at 7 days than after any other period (p=0.031). RP group scored higher for lymphoplasmacytic infiltrate at 14 days than at 90 days (p=0.04).

CONCLUSION

The main contribution of this study was to demonstrate that issues involved with tissue tolerance of a Resilon-containing sealer, RealSeal Sealer, cannot be attributed to its primer content.

A biocompatible model for evaluation of the responses of rat periapical tissue to a new zinc oxide-eugenol sealer

We aimed to establish an experimental animal model to evaluate materials for endodontic therapy. We focused on the biocompatibility of new paste-type zinc oxide-eugenol (ZOE) sealer. The results of this sealer were compared with those of conventional powder/liquid ZOE and eugenol-free sealers. The molars of Wistar rats were extracted and repositioned in the original socket after application of the sealers on the root apices. Mild inflammation occurred in the periapical tissue of the replanted teeth with both ZOE sealers on day 7, whereas the eugenol-free sealer induced severe inflammation. On day 14, the lesions induced by all types of sealers were healed and replaced predominantly by fibrous connective tissue. Thus, all endodontic materials showed high biocompatibility, although the extent of inflammatory reactions during the early stages varied depending on the types of materials. We demonstrated that our animal model was useful for the assessment of the biocompatibility of endodontic materials.

Cytotoxicity of 5 endodontic sealers on L929 cell line and human dental pulp cells

AIM

To investigate the cytotoxicity of five root canal sealers on L929 mouse fibroblasts and primary human dental pulp cells.

METHODOLOGY

Cylindrical specimens of AH Plus (Dentsply De Trey GmbH, Konstanz, Germany), RoekoSeal (Coltène Whaledent, Langenau, Germany), EndoREZ (Ultradent Products Inc., South Jordan, UT, USA), Epiphany (Pentron Clinical Technologies, LLCC, Wallingford, CT, USA) and Activ GP (Brasseller Inc., USA, Savannah, GA, USA) were kept at 37 °C in a humidified atmosphere of 5% CO(2) for thrice the length of the setting time given by the manufacturer. Extraction of specimens was performed after setting in cell growth medium for 1, 4 and 7 days. Undiluted, 50% and 25% diluted eluates were incubated with cultured cells for 24 and 72 h. Cytotoxicity was assessed using MTS colorimetric bioassay. Kruskal-Wallis test and post hoc Dunn's multiple comparison test were used to compare the sealers and diluted/undiluted eluates in terms of cell viability (% of control). Friedman test and post hoc Dunn's multiple comparison test were performed to compare extraction periods. Wilcoxon test was utilized in comparing 24- and 72-h readings.

RESULTS

Undiluted 1-day eluate of Activ GP was significantly more cytotoxic than all other sealers (P < 0.0001). Undiluted 4- and 7-day eluates of Epiphany and Activ GP were significantly more cytotoxic than the other three sealers (P < 0.0001). Diluted eluates of Activ GP and Epiphany were generally less toxic than the undiluted ones. The cytotoxicity of Epiphany significantly increased as the extraction period increased (P < 0.0001). Epiphany became more toxic with time of exposure to cells. No or minimal cytotoxicity was observed with RoekoSeal, AH Plus and EndoREZ.

CONCLUSIONS

The sealers exhibited varying degrees of cytotoxicity dependent on their chemical composition.

Preliminary study of the inflammatory response to subcutaneous implantation of three root canal sealers

AIM

To evaluate the kinetics of the inflammatory tissue response to three root canal sealers using a physicochemical method for quantification of the enhanced vascular permeability and histopathological analysis.

METHODOLOGY

Twenty-eight male Wistar rats randomly assigned to four groups according to the evaluation periods (1, 3, 7 and 14 days) were used to assess the vascular permeability and histopathological reaction to RoekoSeal, AH Plus and Sealapex (new formulation) sealers, using saline and Chloropercha as negative and positive controls, respectively. Seven rats were sacrificed per period. The biocompatibility of the sealers was evaluated spectrophotometrically and histopathologically.

RESULTS

At day 14, Sealapex produced significantly more inflammatory exudate than AH Plus and RoekoSeal (P < 0.05); however, there was no significant difference between AH Plus and RoekoSeal (P > 0.05). Sealapex (new formulation) was the most irritating sealer, producing severe inflammation with the presence of multinucleated giant cells. RoekoSeal was the most biocompatible sealer, producing the least amount of inflammatory exudate.

CONCLUSIONS

RoekoSeal root canal sealer was biocompatible when implanted in connective tissue.

Biocompatibility of four root canal sealers: a histopathological evaluation in rat subcutaneous connective tissue

The aim of this study was to evaluate the subcutaneous biocompatibility of: Epiphany, AH Plus, Pulp Canal Sealer and Sealapex root canal sealers. Sixty rats were randomly assigned to 4 groups, according to the sealer. Polyethylene tubes containing the tested materials were inserted into the connective tissue. The implants were removed after 7, 15 and 30 days, and the tissue samples were processed, stained and examined by light microscopy. The descriptive analysis considered: thickness of the fibrous capsule, severity of the inflammatory reaction, and presence of giant cells. After 7 days, all sealers induced moderate to severe inflammatory reaction. After 15 days, Epiphany and AH Plus sealers showed a moderate inflammatory reaction, while Pulp Canal Sealer and Sealapex induced severe and mild inflammatory reactions, respectively. After 30 days, mild inflammatory reactions were observed for Epiphany, Sealapex and AH Plus. Sealapex induced the lowest inflammatory response at all evaluation periods, and only Pulp Canal Sealer did not show a decreased in the inflammatory reaction over time.

Radiopacity evaluation of root canal sealers containing calcium hydroxide and MTA

The purpose of this study was to evaluate the radiopacity of root canal sealers containing calcium hydroxide and MTA (Acroseal, Sealer 26, Sealapex, Endo CPM Sealer, Epiphany and Intrafill). Five disc-shaped specimens (10 x 1 mm) were fabricated from each material, according to the ISO 6876/2001 standard. After setting of the materials, radiographs were taken using occlusal film and a graduated aluminum stepwedge varying from 2 to 16 mm in thickness. The dental X-ray unit (GE1000) was set at 50 kVp, 10 mA, 18 pulses/s and distance of 33.5 cm. The radiographs were digitized and the radiopacity compared to that of the aluminum stepwedge using VIXWIN-2000 software (Gendex). The data (mmAl) were analyzed statistically by ANOVA and Tukey's test at the 5% significance level. Epiphany and Intrafill presented the highest radiopacity values (8.3 mmAl and 7.5 mmAl respectively, p < 0.05) followed by Sealer 26 (6.3 mmAl), Sealapex (6.1 mmAl) and Endo CPM Sealer (6 mmAl). Acroseal was the least radiopaque material (4 mmAl, p < 0.05). In conclusion, the calcium hydroxide- and MTA-containing root canal sealers had different radiopacities. However, all materials presented radiopacity values above the minimum recommended by the ISO standard.

Periapical repair after root canal filling with different root canal sealers

The aim of this study was to evaluate periapical repair after root canal filling with different endodontic sealers. Sixty-four root canals from dog´s teeth were filled, divided into 4 groups (n=16). Root canals were instrumented with K-type files and irrigated with 1% sodium hypochlorite solution. Root canals were filled in the same session by active lateral condensation of the cones and sealers: Intrafill, AH Plus, Roeko Seal and Resilon/Epiphany System. After 90 days, the animals were euthanized and the tissues to be evaluated were processed and stained with hematoxylin and eosin. For histopathological analysis, the following parameters were evaluated: inflammatory process, mineralized tissue resorption, and apical mineralized tissue deposition. Histopathological analysis demonstrated that Intrafill had less favorable results in terms of apical and periapical repair, compared to the other sealers (p<0.05). AH Plus, Roeko Seal, and Epiphany sealers had similar and satisfactory results (p>0.05). In conclusion, AH Plus and the materials Roeko Seal and Epiphany are good options for clinical use in Endodontics.