Sealer Cement Research Articles

The degree of crown discoloration induced by a bioceramic and other conventional endodontic sealers

Objective: The aim of this study was to compare the degree of crown discoloration induced by a novel bioceramic and conventional endodontic sealers. Materials and Methods: Thirty extracted maxillary central incisors were selected and randomly divided into three groups (n = 10), according to the assigned sealer: G1 – TotalFill, G2 – Apexit Plus, and G3 – AH Plus. Baseline color of the labial surfaces was obtained using a spectrophotometer. Standardized root canal preparation and obturation were completed using ProTaper system and gutta-percha with sealer cement. Access openings were sealed using light-cured resin composite. Specimens were stored in saline and placed in an incubator at 37°C until testing. Crown color was reassessed after 1 week, 1 month, and 3 months. Color change from baseline was calculated using the following equation: ΔE* = ([ΔL*]2 + [Δa*]2 + [Δb*]2)½. Data were analyzed using ANOVA, t-test, and Tukey post hoc test (at P≤ 0.05). Result: In the three groups tested, the highest mean value of color change was found after 3 months, whereas the lowest was at 1 week. Changes were significant in all groups (P Conclusion: It was concluded that all sealers tested result in a measurable and gradual tooth color change. While the bioceramic sealer resulted in a slightly higher color change compared to calcium hydroxide- and resin-based sealers, the difference was not considerable.

Very low certainty in evidence suggesting no differences in caries development when comparing glass ionomer cement sealants and resin-based sealants

Alirezaei M, Bagherian A, Sarraf Shirazi A. Glass ionomer cements as fissure sealing materials: yes or no? A systematic review and meta-analysis. JADA. 2018;149(7):640-649.e9. https://jada.ada.org/article/S0002-8177(18)30106-5/fulltext.

The Evaluation of Setting Time and FTIR Spectroscopy of Carbonate Apatite Cement as Endodontic Sealer

The carbonate apatite (CO3Ap) cement as an endodontic sealer play an essential role for endodontics treatment due to its potential to obturate root canal system as one of the most important part in endodontic treatment. Moreover, the CO3Ap has probability of similarities with composition of root dentin. Recently, the setting time of commercial endodontic sealer has 4 hours to 1 day. Therefore, the aim of this present study is to evaluate setting time and to determine the functional group of the new material composition for endodontic sealer. CO3Ap cement sealer was prepared by mixing dicalcium phosphate anhydrous (DCPA), vaterite and calcium hydroxide [Ca (OH)2] with 0.2 mol/L Na2HPO4 containing 1% sodium carboxymethylcellulose (NaCMC) and 32 μg thymoquinone, with liquid to powder ratio of 0.6. The setting time was evaluated by Vicat needle method as describe on modification ISO 1566 for zinc phosphate cement. Five compositions of powder ratio were prepared in this study. The set CO3Ap cement sample was evaluated by Fourier Transform Infrared Spectroscopy (FTIR) to define the functional group of the sample. Setting time evaluation indicated that the average setting time of CO3Ap cement was 21 minutes of five compositions. The FTIR analyses revealed that the CO32- groups were detected, so the results could determine as B-type CO3Ap.The CO3Ap cement was considered fast setting as an endodontic sealer compared to sealers made from other base and proven to have similarities with the components of root dentin.

Penyerapan Air Dan Kelarutan Bahan Semen Ionomer Kaca Sebagai Penutup Pit Dan Fisur Gigi

BACKGROUND: Pit and fissure sealants are materials that are often used for preventive maintenance, especially on occlusal surfaces of teeth that are susceptible to caries. All restoration materials that come into contact with water will experience 2 mechanisms, namely the absorption of water, which causes matrix swelling and increased mass and water solubility, namely the release of components from unreacted monomers and causing reduced mass. OBJECTIVE: Measure the value of water absorption and solubility of glass ionomer cement as a cover of the pit and fissure of the tooth. METHODS: 18 specimens of glass ionomer cement sealant material manipulated according to the manufacturer's instructions consisted of six specimens measuring 15 mm in diameter and 1 mm in thickness made for each immersion time. The specimen was put into a desiccator at 37°C for 22 hours and then put into another desiccator with a temperature of 23°C for 2 hours. The specimen was weighed with a precision scale of 0.1 mg. Measurements are carried out repeatedly until a constant mass is obtained (M1). Next, the specimen was put into 40 ml of aquabides and stored in a desiccator at 37°C for 1 day, 2 days and 7 days. At the end of each immersion time, the specimen was removed from aquabides, dried with suction paper and vibrated in the air for 15 seconds. Specimens are weighed to get M2. The specimens were reconditioned to the desiccator at 37°C for 22 hours and then put into another desiccator with a temperature of 23°C for 2 hours and this procedure was repeated one day later, then the mass was weighed repeatedly until a constant mass was obtained (M3). RESEARCH RESULTS: The Kruskal-Wallis statistical test shows that there is no significant difference in the average water absorption value and solubility of materials for immersion for 1 day, 2 days and 7 days. CONCLUSIONS AND RECOMMENDATIONS: The absorption rate of glass ionomer cement as a cover of dental pit & fissure decreased until the second day and increased until the seventh day, with an average absorption of water for 1 day immersion of 42.68mg/mm³, 2 days 40, 53mg/mm³ and 7 days 42.99mg/mm³. Solubility value in water of glass ionomer cement as a cover of dental pit & fissure decreased until the second day then increased until the seventh day, with an average solubility of material for immersion for 1 day at 41.46mg/mm³, 2 days 39.39mg/mm³ and 7 days 41,91mg/mm³. It was said that there was no significant difference in the value of water absorption and solubility of materials during the immersion period of 1, 2 and 7 days. It is recommended that in the application of glass ionomer cement as a cover of dental pits and fissures, please note in the provision of varnish or protector to reduce the occurrence of water absorption and solubility of the material. In addition, the pit and fissure of the tooth that has been covered should be controlled 3 months later to find out if the cover is still intact or has been damaged or loose. It is also recommended that there is further research to determine the value of water absorption and solubility of ingredients if soaked in artificial saliva for more than 7 days.

Efficacy of ProTaper rotary instruments in removing filling materials during root canal retreatment

The aim of the this study was to investigate the efficacy of ProTaper rotaryinstruments compared to hand instrumentation with Hedstrom files, with and withoutthe use of a solvent (eucalyptol) in the retreatment of gutta-percha filled root canals.Roots of forty extracted single-rooted maxillary anterior teeth with straight root canalswere utilized in this study. The root canals were prepared using step-back techniqueand obturated with laterally condensed gutta-percha and sealer cement. The rootsrandomly divided into four groups with ten specimens each. Removal of gutta-perchawas performed using ProTaper and Hedstrom files, both were used with and withoutthe solvent eucalyptol. Both, time taken to reach the working length and time taken tocomplete removal of gutta-percha were recorded. Statistical analysis of the collecteddata revealed a highly significant decrease in the working time when ProTaper wasused to remove gutta-percha compared with Hedstrom files. A highly significantdecrease in the working time was found when eucalyptol was used with ProTaper. Nosignificant difference existed between the treatments using Hedstrom with or withoutthe use of eucalyptol.

Interfacial Characteristics and Cytocompatibility of Hydraulic Sealer Cements

IntroductionThe stability and long-term success of root canal obturation depends on the choice of sealer because the sealer bonds to the dentin and stabilizes the solid cone. Furthermore, the sealer needs to be nontoxic because sealer toxicity will certainly lead to treatment failure. The aim of this study was to assess the sealer-dentin interface of 3 hydraulic root canal sealers and to evaluate their cytocompatibility compared with AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany). MethodsFour dental root canal sealers were assessed. AH Plus, MTA Fillapex (Angelus, Londrina, Brazil), BioRoot RCS (Septodont, Saint-Maur-des-Fossés, France), and Endoseal (Maruchi, Wonju-si, Gangwon-do, South Korea) were characterized using scanning electron microscopy and energy-dispersive spectroscopy. The sealer-tooth interface was assessed by confocal microscopy and scanning electron microscopy, and biocompatibility was measured by assessing the cell metabolic function using direct contact assays and alkaline phosphatase activity. ResultsThe tricalcium silicate–based sealers presented a different microstructure and elemental composition despite their similar chemistry and classification. BioRoot RCS was free of aluminum, and all sealers presented different radiopacifying elements. The sealer penetration in the dentinal tubules and interfacial characteristics were different. The migration of silicon was evident from sealer to tooth for all sealers containing tricalcium silicate. MTA Fillapex and BioRoot RCS exhibited the best cytocompatibility in both the direct contact test and alkaline phosphatase activity. ConclusionsThe use of hydraulic calcium silicate–based sealers has introduced a different material type to endodontics. These materials are different than other sealers mostly because of their hydraulic nature and their interaction with the environment. Although the sealers tested had a similar chemistry, their cytocompatibility and bonding mechanisms were diverse.

Natural products in endodontics.

Herbal remedies are used throughout the world, either in earlier or in recent times. The number of studies on this alternative therapeutic system increased in the last decades. In this paper, the relevant literature on the use of natural products in root canal therapy is revised from a MEDLINE database search. The uses of medicinal plants in endodontics include cleaning and disinfection of root canals, intracanal medicaments between appointments, sealer cements, and for removal of obturation material. Other studies showed the effect of natural products in pulpal and dentin repair. Their use is anecdotal, and their effectiveness showed to be variable and is always compared to the chemical standards currently being used. Alkaloids, coumarins, saponins, and flavonoids are aromatic substances that are produced by plants and evaluated for their therapeutic potential. Further investigation into benefits of natural products is warranted.

Fabrication of Carbonate Apatite Cement as Endodontic Sealer

Carbonate Apatite (CO3Ap) cement has been widely used for bone substitute. It is known that CO3Ap crystals have the close composition to natural bone. It is expected that CO3Ap cement may play an essential role in endodontics treatment, particularly as an endodontic sealer due to its potential to obturate root canal system to a more hermetic and stable environment. Therefore, the aim of this study is to fabricate CO3Ap cement as a new material for endodontic sealer. The CO3Ap cement sealer was prepared by mixing dicalcium phosphate anhydrous (DCPA), vaterite and calcium hydroxide [Ca(OH)2] with 0.2 mol/L Na2HPO4 containing 1% sodium carboxymethyl cellulose (NaCMC) and 32 µg thymoquinone, with liquid to powder ratio of 0.6. The set cement was incubated at 37°C under 100% relative humidity for 72 h. In this study, five compositions of powder ratio were prepared. The diametral tensile strength (DTS) evaluation indicated that CO3Ap cement made of 60% DCPA, 30% Vaterite and 10% Ca(OH)2 has the highest mechanical strength compared with the other compositions. X-ray diffraction (XRD) analysis of the set cement with the highest DTS value indicated that CO3Ap crystals were successfully formed. The set cement with the highest DTS value showed the highest density compared with the other compositions evidenced from scanning electron microscope (SEM) images. In conclusion, the CO3Ap cement was successfully fabricated by mixing DCPA, vaterite and Ca(OH)2. The CO3Ap cement prepared from 60% DCPA, 30% Vaterite and 10% Ca(OH)2 demonstrated the highest DTS value compared with the other compositions.

A zinc oxide-modified hydroxyapatite-based cement facilitated new crystalline-stoichiometric and amorphous apatite precipitation on dentine.

To evaluate the remineralization ability of two endodontic sealer cements. Mid-coronal dentine surfaces were subjected to: (i) 37% phosphoric acid (PA) or (ii) 0.5mol L-1 ethylenediaminetetraacetic acid (EDTA) conditioning prior to the application of two experimental hydroxyapatite-based cements, containing sodium hydroxide (calcypatite) or zinc oxide oxiapatite respectively. Samples were stored in simulated body fluid for 24h or 21days. Remineralization of the dentine surfaces were studied by Raman spectroscopy (mapping with K-means cluster and hierarchical cluster analysis) was undertaken. Nanoroughness and collagen fibril width measurements were performed with an atomic force microscopy. ANOVA and Student-Newman-Keuls test were performed (α=0.05). Phosphoric acid+oxiapatite promoted both the highest dentine mineralization (P<0.05) and crystallographic maturity at the dentine surface. Noncrystalline amorphous-like apatites were also formed. Dentine treated with PA+calcypatite attained the roughest surface (P<0.05) with minimal fibril width (P<0.05). Cross-linking of collagen only became greater in the group PA+oxiapatite after 21days. The maximum relative mineral concentration and structure of collagen linked to the amide I and ratio amide III/AGEs was obtained after using PA+calcypatite at 21-days time-point (P<0.05). EDTA produced a lower stoichiometric hydroxyapatite (P<0.05) with decreased maturity, at the expense of carbonate band widening, although it favoured the nucleation of carbonated calcium phosphate. Dentine surfaces treated with PA+oxiapatite attained the highest dentine remineralization with both crystalline-stoichiometric and amorphous apatites, at 21days. EDTA conditioning facilitated amorphous-bulk mineral precipitation. The amorphization was more intense after using oxiapatite and provided an ion-rich environment favouring insitu dentine remineralization.

Cellular Responses in Human Dental Pulp Stem Cells Treated with Three Endodontic Materials.

Human dental pulp stem cells (HDPSCs) are of special relevance in future regenerative dental therapies. Characterizing cytotoxicity and genotoxicity produced by endodontic materials is required to evaluate the potential for regeneration of injured tissues in future strategies combining regenerative and root canal therapies. This study explores the cytotoxicity and genotoxicity mediated by oxidative stress of three endodontic materials that are widely used on HDPSCs: a mineral trioxide aggregate (MTA-Angelus white), an epoxy resin sealant (AH-Plus cement), and an MTA-based cement sealer (MTA-Fillapex). Cell viability and cell death rate were assessed by flow cytometry. Oxidative stress was measured by OxyBlot. Levels of antioxidant enzymes were evaluated by Western blot. Genotoxicity was studied by quantifying the expression levels of DNA damage sensors such as ATM and RAD53 genes and DNA damage repair sensors such as RAD51 and PARP-1. Results indicate that AH-Plus increased apoptosis, oxidative stress, and genotoxicity markers in HDPSCs. MTA-Fillapex was the most cytotoxic oxidative stress inductor and genotoxic material for HDPSCs at longer times in preincubated cell culture medium, and MTA-Angelus was less cytotoxic and genotoxic than AH-Plus and MTA-Fillapex at all times assayed.

Clinical aspects of Atraumatic Restorative Treatment

The objective of Atraumatic Restorative Treatment is to prevent carious lesion development and to stop its progression. This can be achieved, among other ways, by placing high-viscosity glass-ionomer cement sealants in pits and fissures in the enamel. A second area of utilisation is the treatment of dentine carious lesions. The weakened demineralised dentine can effectively be removed using hand instruments only. An accurately placed sealant-restoration prevents remaining cariogenic bacteria from reigniting the process of decay and allows the residual carious dentine to remineralise. To achieve good results using Atraumatic Restorative Treatment, an oral healthcare provider should complete a programme of instruction and have command of sufficient knowledge of cariology, the principles of treatment and the available restorative materials. High-viscosity glass-ionomer cement is the material of first choice for the prevention of enamel caries and the treatment of dentine carious lesions, but there is a constant search for improvements to this material and for a qualitatively better alternative.

A regeneration-based, nonobturation root-canal treatment for fully-mature teeth: Six years' experience with "SealBio".

Objectives:To provide scientific evidence on the outcome of a large number of cases treated by SealBio over the longer follow-up period.Materials and Methods:One hundred and thirty-four teeth in 116 patients presenting with pulp and periapical disease were randomly recruited between 2009 and 2014. SealBio was performed, and cases were followed up at regular intervals up to 6-year.Results:Of the total 134 teeth treated, 16 teeth could not be followed up and 9 cases failed (7.62% of cases). In only 4 cases (approximately 3.38% of cases), the failure could be directly attributed to endodontic causes. In the remaining 5 cases, coronal leakage from under the crown margins or dislodged restoration was found after 3-5 years of treatment.Conclusions:SealBio was found to be a successful, nonobturation, regeneration-based endodontic treatment protocol. By cell homing of endogenous stem cells, a biological seal rather than an artificial seal with gutta-percha and sealer cement is possible to achieve. It is highly cost saving and easier to perform, in addition to other advantages, such as retreatment is much simpler, and postcore restoration is possible after SealBio treatment.

Retention evaluation of two glass ionomer cement sealants: six-month clinical follow-up

Objective: The aim of this study was to evaluate the retention of glass ionomer sealant, Vitro Molar(r) (DFL) and Ketac Molar Easy Mix(r) (3 m ESPE) as pit and fissure sealants on first permanent molars, fully or partially erupted. Methods: The study sample consisted of 412 molars, among 110 children. The sealant retention was evaluated after 6 months of the application. Results: The results were collected through digital photographs and the retention results were assessed by the following System: score 0 - total retention; score 1 - sealant present in more than 50% of the pit and fissure system; score 2 - sealant present in less than 50% of the pit and fissure system; score 3 - missing sealant. Regarding the presence of the sealants in less than 50% of the occlusal surface, lower percentages were found for the two materials used as follows: score score 2 - Vitro Molar(r) (9,52% examiner 1 and 11.9% examiner 2) and score 2 - Ketac Molar Easy Mix(r)(9.52% examiner 1 and 10.71% examiner 2). Approximately 90% of the teeth sealed with Ketac Molar Easy Mix(r)or Vitro Molar(r) presented total loss (score 3). Thus, there was no statistical difference between the materials and between the examiners (p&gt;0.05). Conclusion: Therefore it was concluded that the sealant retention in the studied population was not satisfactory for any of the materials used.

Dynamic intratubular biomineralization following root canal obturation with pozzolan-based mineral trioxide aggregate sealer cement.

SummaryThe application of mineral trioxide aggregates (MTA) cement during the root canal obturation is gaining concern due to its bioactive characteristic to form an apatite in dentinal tubules. In this regard, this study was to assess the biomineralization of dentinal tubules following root canal obturation by using pozzolan‐based (Pz‐) MTA sealer cement (EndoSeal MTA, Maruchi). Sixty curved roots (mesiobuccal, distobuccal) from human maxillary molars were instrumented and prepared for root canal obturation. The canals were obturated with gutta‐percha (GP) and Pz‐MTA sealer by using continuous wave of condensation technique. Canals obturated solely with ProRoot MTA (Dentsply Tulsa Dental) or Pz‐MTA sealer were used for comparison. In order to evaluate the biomineralization ability under different conditions, the PBS pretreatment before the root canal obturation was performed in each additional samples. At dentin‐material interfaces, the extension of intratubular biomineralization was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy. When the root canal was obturated with GP and Pz‐MTA sealer, enhanced biomineralization of the dentinal tubules beyond the penetrated sealer tag was confirmed under the SEM observation (p < 0.05). Mineralized apatite structures (calcium/phosphorous ratio, 1.45–1.89) connecting its way through the dentinal tubules were detected at 350–400 μm from the tubule orifice, and the pre‐crystallization seeds were also observed along the intra‐ and/or inter‐tubular collagen fiber. Intratubular biomineralization depth was significantly enhanced in all PBS pretreated canals (p < 0.05). Pz‐MTA cement can be used as a promising bioactive root canal sealer to enhance biomineralization of dentinal tubules under controlled environment. SCANNING 38:50–56, 2016. © 2015 The Authors. Scanning Published by Wiley Periodicals, Inc.

Thin and thick layers of resin-based sealer cement bonded to root dentine compared: Adhesive behaviour.

This study aims to evaluate tensile and shear bond strengths of one epoxy (AH) and two methacrylate resin-based sealers (EZ and RS) in thin and thick layers bonded to root dentine. An alignment device was prepared for accurate positioning of 20 root dentine cylinders in a predefined gap of 0.1 or 1 mm. Sealer was placed in the interface. Bond strength tests were conducted. Mode of failures and representative surfaces were evaluated. Data were analysed using anova and post-hoc tests, with P < 0.05. The thick layer of sealer produced higher bond strength, except for the shear bond strength of EZ. Significant differences between thin and thick layers were found only in tensile bond strengths of AH and RS. Mixed type of failure was constantly found with all sealers. Bond strengths of thick layers of resin-based sealers to root dentine tended to be higher than with thin layers.

Mineral trioxide aggregate: present and future developments

Portland cement is used in the building industry to make concrete. It is hydraulic and thus it develops its properties well in the presence of moisture. The oral environment is inherently wet, however, all dental materials need a dry field for optimal performance. A mixture of Portland cement and bismuth oxide was developed and marketed as mineral trioxide aggregate (MTA). The first formulation was gray in color followed by a white version and eventually by various similar materials, which are all composed of a tricalcium silicate‐based cement and radiopacifier. The MTA was originally suggested for particular clinical uses, such as root‐end filling and perforation repair, where maintenance of a dry field is difficult. The suggested uses were extended to apexification and dressing over pulpotomies, pulp capping and also as a sealer cement. The multipurpose use of MTA necessitated the development of improved formulations where material additives were included to the original cement/radiopacifier formulation. These additives supposedly enhance the material's properties and improve its function. Furthermore, the original Portland cement formulation was replaced with tricalcium silicate to avoid the inclusion of an aluminum phase and eliminate the inclusion of trace elements. The bismuth oxide was also replaced with alternative radiopacifiers. The multifaceted use of MTA allows the material to come into contact with different oral environmental conditions, including blood, saliva, tissue fluids, dental restorative materials, tooth structure and even air. These different conditions affect the properties and setting of the material. Future developments should further investigate the material's interactions and strive to create materials which are suited to a specific use.

Marginal adaptation of mineral trioxide aggregate (MTA) to root dentin surface with orthograde/retrograde application techniques: A microcomputed tomographic analysis.

Background:Achieving a good apical seal for root canals is known to be associated with good mineral trioxide aggregate (MTA) adaptation to dentin.Aims:This study aims to compare the marginal adaptation of MTA with root dentin between orthograde and retrograde application techniques using microcomputed tomography (micro-CT) analysis.Settings and Design:Fifty-two single-rooted human teeth were divided into four equal groups: (Group 1) Retrograde MTA (RMTA), (Group 2) Orthograde MTA (OMTA), (Group 3) Etched RMTA (ERMTA), and (Group 4) Etched OMTA (EOMTA).Materials and Methods:For Group 1, 3-mm retrograde cavities were prepared and filled with MTA. For Group 2, the apical 6 mm of the canals were filled with MTA and sealed with sealer cement and warm gutta-percha. In Groups 3 and 4, canals were treated the same as Groups 1 and 2, respectively, except that before placing the MTA, canals were irrigated with 17% ethylenediaminetetraacetic acid (EDTA). After 48 hours, all the teeth were analyzed using a micro-CT scanner.Statistical Analysis:Mean dentin-MTA contact and the mean length and width of each gap was analysed using one-way analysis of variance (ANOVA). Statistical significance was set at an α level of 5%.Results:No significant difference in gap volumes was observed in the dentin-MTA adaptation in both orthograde and retrograde application techniques. However, significant difference in the gap volumes was observed between RMTA and ERMTA (P = 0.045). Etching significantly improved the MTA-Dentin adaptation (P < 0.05). The type of application technique did not significantly improve the dentin-MTA adaptation, instead with the use of 17% EDTA, a significant improvement could be achieved.Conclusion:Within the limitations of the present study, it concludes that MTA adaptation to dentin tooth structure is not significantly different between an orthograde and retrograde approach. However, the use of EDTA significantly improved the MTA-Dentin adaptation.

Antibacterial efficacy of three root canal sealers against Enterococcus faecalis and Candida albicans: An in vitro study

Aim: The aim of this in vitro study was to compare the antimicrobial efficacy of calcium hydroxide-based sealer (Apexit Plus), zinc oxide eugenol-based sealer (Endoflas FS) and resin-based sealer (EndoRez) root canal sealers against Enterococcus faecalis microbial type culture collection (MTCC) 439 and Candida albicans MTCC 239 using agar diffusion test. Materials and Methods: In the present study, 20 Mueller Hinton agar (MH agar) plates were employed. Three wells were made by removal of agar at equidistant points and filled with root canal sealers according to manufacturer's instructions. The strains of the bacteria and fungi used in this study were E. faecalis MTCC 439 and C. albicans MTCC 227. Both micro organisms were grown at 37°C for 24 h in MH Broth and seeded into MH agar to produce a turbidity of 0.5 on the McFarland scale, which corresponds to a concentration of 10 8 CFU/mL. This MH broth was used as a second layer. The seeded agar was then added over the plates immediately after the insertion of sealer cements. After incubation, the diameters of zones of inhibition around the plates were measured. Results: The results were statistically analyzed using two way ANOVA test. Against both the micro organisms used in this study, Endoflas FS showed the largest zones of inhibition followed by Apexit Plus and EndoRez. Conclusion: Within the limitations of this study, it can be concluded that: Root canal sealers showed different inhibitory effects depending on their types and microbial strains tested. Against Enterococcus faecalis and Candida albicans, zinc oxide based sealers showed the highest microbial zones of inhibition followed by the calcium hydroxide based sealer and resin based sealer respectively

A Comparative Study of Two High-Viscosity Ionomeric Cements for the Sealing of Newly Erupted Permanent Molars

Objective: To compare the retention and preventive aspects of two different types of high-viscosity glass ionomer cements for newly erupted permanent molars, considering the cost-benefit ratio in relation to public health. Material and Methods: fifty-four children (5-12 years) with erupted molars were selected. One hundred and fifty-four teeth were sealed, 75 with Ketac Molar (KM) and 79 with Vitro Molar (VM). Before and after sealant application, photos were taken and condensation silicone casts were produced in order to better classify tooth eruption stage and to assess the sealant retention rate. Results: Fifty-six percent of teeth sealed with KM showed fully retained material (FR) after the 5-month follow-up period; 18.4 % showed KM in two-thirds of the occlusal surface (partial retention 2- PP2); 23.7 % in one third of the occlusal surface (partial retention 1-PP1); and only 1.3 % of sealed teeth showed total loss (TL). Among teeth sealed with VM, 28.8 % showed total retention (TR) of the sealant after 5 months; 7.5 % of sealants were present in two-thirds of the occlusal surface (PP2); 10% were present in one third of the occlusal surface (PP1), and 53.7 % showed total loss of the sealant (TL). The development of only one active white spot caries lesion after total sealant loss was observed in the VM group. Conclusion: Occlusal surfaces of newly erupted permanent molars sealed with high-viscosity KM glass ionomer cement exhibited higher retention when compared to VM after a 5-the development of carious lesions in sealed teeth was similar in both materials, which confirms the good clinical performance of glass ionomer cement sealants in the evaluation period, being highly significant when considering the cost-benefit ratio in relation to public health (KM cost is 4 times higher than VM cost).

Critical Evaluation of the Push-out Test for Root Canal Filling Materials

IntroductionThe push-out test has been widely used in experimental endodontics but has been criticized on technical grounds particularly because the soft-core material undergoes plastic deformation under load. This study systematically evaluated the technique by comparing push-out strength and load profiles in relation to core material stiffness, canal diameter, punch diameter, sample orientation, and mode of failure. MethodsStraight palatal roots of 90 maxillary molars were obturated with an epoxy resin–based sealer alone (10 roots) or gutta-percha (70) or epoxy resin (10) cores with a thin layer of sealer cement. Roots were embedded in mounting resin vertically or at an angle of 5° or 10° to the long axis of the root. One-millimeter sections were tested using a universal testing machine with a punch diameter corresponding to 50%, 75%, or 90% of the canal diameter. Bond strengths (MPa) were calculated, and data were analyzed using analysis of variance with post hoc Tukey multiple comparisons (P < .05). After push out, core materials and canal walls were examined using scanning electron microscopy. ResultsPush-out strength was affected by core material stiffness. Angulation up to 10° from vertical had little effect on push-out strength, but load profiles were strongly influenced by orientation. No effect of the punch diameter was observed when the diameter was 90% of the canal diameter, but push-out strength was lower when the punch diameter was 50%–60% of the canal size. ConclusionsDespite limitations, the push-out test may still be suitable for ranking the bonding of root filling materials.