Małgorzata Pawińska

Cytotoxicity evaluation of three light-cured dentin adhesive materials on human gingival fibroblasts, ex vivo

PURPOSE To evaluate the cytotoxic effects of three current light-cured dentin adhesives, in both uncured and post-cured conditions, on human gingival fibroblasts. MATERIAL AND METHODS The materials tested were Heliobond, Adper Single Bond 2 and Xeno V, which are characterized by various compositions and application procedures. Each agent, in volumes of 5 and 10 μL, was tested after polymerization, and those unpolymerized were diluted in DMEM to 10-3 and 10-5. The cytotoxicity of the adhesives was assessed on the basis of a test of cell viability in a culture of human gingival fibroblasts, with the use of tetrazolic salt (MTT assay). RESULTS The results showed that, among the adhesive/bonding systems tested, Xeno V was the least cytotoxic. There were statistically significant differences in cell survival between polymerized Xeno V, Adper Single Bond 2 and Heliobond in the amount of 5 μL as well as between the Xeno V and Adper Single Bond 2 in 10-5 dilutions. The tested adhesives were more toxic in the polymerized form than in the dilutions. Samples of 10 μL resulted in a lower survival percentage of fibroblasts compared to 5 μL. CONCLUSION All the tested adhesives demonstrated cytopathic effects towards human gingival fibroblasts, but varied in their cytotoxicity. This has clinical implications. Dentists should follow the rules of adhesive application, precisely dose them and not allow direct contact with the gums as, even after polymerization, adhesive agents exhibit potential cytotoxic activity.

A microcomputed tomography-based comparison of root canal filling quality following different instrumentation and obturation techniques.

Objective: With a microcomputed tomography (microCT) imaging device, we aimed to quantitatively evaluate root canal fillings after commonly used endodontic procedures and also tested the suitability of microCT for this purpose. Materials and Methods: Eighty single roots were instrumented and obturated with gutta-percha and Tubli-Seal. They were divided into 4 groups of 20. The Hand groups were instrumented with hand files and filled with thermoplastic (Th) compaction and cold lateral (CL) condensation, i.e. Hand-Th and Hand-CL, respectively. The Rot groups, i.e. Rot-Th and Rot-CL, were instrumented with a rotary ProFile system and filled as above. The roots were scanned and 3-dimensional (3D) visualization was obtained. The number, size, percentage of volume and distribution of voids at the filling/dentine interface (i-voids) and voids surrounded by filling material (s-voids) were measured. Results: Canal fillings differed significantly with regard to the size of both types of voids and the average number of i-voids. All canals presented a low volume of voids. The highest percentage (0.69%) was found for i-voids in the Hand-CL group, while the lowest volume (0.11% for s-voids and 0.14% for i-voids) was in the Hand-Th canals. Apically, in the last 3 mm, i-voids were observed mainly in the Th groups, and s-voids occurred mostly in the coronal part of the canal filling in all cases. Conclusion: MicroCT was a useful tool for 3D quantitative evaluations of these root canal fillings. None of the root canal instrumentation and filling methods ensured void-free obturation. CL condensation produced mainly i-voids. With Th compaction, internal s-voids were particularly common, but there were mainly i-voids in the apical part.

New endodontic obturation systems and their interfacial bond strength with intraradicular dentine – ex vivo studies

PURPOSE To comparatively evaluate adhesive properties of selected root canal fillings through the measurement of the material-dentine interfacial bond strength. MATERIAL AND METHODS Fifty extracted single-rooted human teeth with one canal each were prepared using Hero instruments to size 30.04. Teeth were divided into four subgroups depending on the root canal filling material and the method of obturation: Resilon/Epiphany - a thermoplastic method (IA), Resilon/Epiphany - a matching single-point method (IB), gutta-percha/Roeko Seal Automix - a thermoplastic method (IIA) and gutta-percha/Roeko Seal Automix - a matching single-point method (IIB). The obturated roots were cut perpendicular to the long axis to create 1.7 mm thick slices. The bond strength was measured for each test slice with push -out testing machine. RESULTS The highest push-out bond strength was registered in subgroup IB (3.98 ± 1.33 MPa). Significantly lower bond strength was observed in subgroups IA (0.50 ± 0.24 MPa), IIA (0.33 ± 0.18 MPa) and IIB (0.08 ± 0.03 MPa) (p<0.001). No statistically significant differences in material-dentine interfacial bond strength values were observed between IA and IIA, IA and IIB, IIA and IIB subgroups (p > 0.05). CONCLUSIONS The push-out bond strength of the material-dentine interface was dependent on the type of material used and the root canal filling technique. The R/E system exhibited better adhesion ability to intraradicular dentine than G/RSA. The highest bond strength was observed for Resilon/Epiphany introduced with the single-cone technique.

Assessment of cytotoxic potential of root canal sealers after hardening - an ex vivo study.

AIM The aim of this study was to perform a comparative assessment of the toxic action of root canal sealers currently on the market on human gingival fibroblasts after setting. MATERIAL/METHODS The inserts with an equal quantity of set root canal sealers were transferred into 24-well culture dishes containing human gingival fibroblasts cultured in Dulbeccos Modified Eagles Medium (DMEM) supplemented with 10% fetal calf serum (FCS). The dishes with materials were incubated at 37°C, 100% humidity and in an atmosphere of 5% CO2 for 24 h. The cytotoxic effects of the root canal materials were measured by the mitochondrial succinate dehydrogenase activity in living cells using tetrazolium bromide (MTT assay). RESULTS Epiphany and Sealapex exhibited high toxicity towards human gingival fibroblasts - 25.57% ± 0.88 and 27.63 % ± 2.35 respectively (less than 30% live cells in the culture). The remaining materials were characterized by lack of a cytotoxic effect (over 90% of live cells in the culture). None of the preparations exhibited moderate or low toxicity. CONCLUSIONS The majority of root canal sealers tested after hardening were well tolerated by human gingival fibroblasts. Only two materials were characterized by high toxicity: with methacrylate (Epiphany) and calcium hydroxide (Sealapex).

Evaluation of cytotoxicity and pH changes generated by various dental pulp capping materials — an in vitro study

INTRODUCTION Various materials are used in direct dental pulp capping method. Their biocompatibility and alkalizing abilities are of primary importance affecting therapeutic effects. The aim of this study was to evaluate and compare the cytotoxicity of various pulp-capping materials on human gingival fibroblasts and investigate the pH changes induced by these materials. MATERIAL AND METHODS Human gingival fibroblasts were cultured with nine direct pulp materials using culture plate inserts. The cytotoxic effects were recorded by using an MTT-based colorimetric assay after 3 and 24 h. In the second part of the experiment, the materials were inserted in dialysis tubes and transferred into plastic vials containing deionized water. The changes of the medium pH were measured after 3 and 24 h. RESULTS We showed differences in cell viability of gingival fibroblasts after varied time of exposition for the tested materials. Cell viability after 24 h increased for Dycal, Biopulp, and Calcipro, and decreased for Calcipulpe, Angelus, Angelus White, and ProRoot Regular. Cell viability for ProRoot and Life did not change. Non-setting calcium hydroxide preparations followed by the MTA group and setting calcium hydroxide materials produced the highest pH. All the tested materials significantly increased pH (p < 0.0001) at 24 h. CONCLUSIONS Currently used pulp capping materials varied in their cytotoxicity relative to human gingival fibroblasts and their alkalizing capacities. Since most likely pH does not affect the viability of cultured cells, further investigations are required to determine physicochemical properties of these materials and the biological activity of the dental pulp.

Evaluation of the cytotoxicity of selected conventional glass ionomer cements on human gingival fibroblasts

BACKGROUND Dentistry materials are the most frequently used substitutes of human tissues. Therefore, an assessment of dental filling materials should cover not only their chemical, physical, and mechanical characteristics, but also their cytotoxicity. OBJECTIVES To compare the cytotoxic effects of 13 conventional glass ionomer cements on human gingival fibroblasts. MATERIAL AND METHODS The assessment was conducted using the MTT test. Six samples were prepared for each material. Culture plates with cells and inserts with the materials were incubated at 37°C, 5% CO2, and 95% humidity for 24 h. Then the inserts were removed, 1 mL of MTT was added in the amount of 0.5 mg/1 mL of the medium, and the samples were incubated in the described conditions without light for 2 h. The optical density was measured with an absorption spectrophotometer at a wavelength of 560 nm. RESULTS The cytotoxic effects of the Argion Molar was significantly stronger than the Fuji Triage (p = 0.007), Chemfil Molar (p < 0.0001), and Ionofil Molar AC Quick (p < 0.001). The Fuji IX GP and Fuji IX Extra had a significantly stronger adverse effect than the Chemfil Molar (p = 0.014, p = 0.029, respectively) and Ionofil Molar AC Quick (p = 0.017, p = 0.034, respectively). The cements from the low cytotoxicity group were significantly more toxic vs materials whose presence resulted in fibroblast growth (p < 0.001). CONCLUSIONS The research conducted indicates that, although the materials studied may belong to the same group, they are characterized by low, yet not uniform, cytotoxicity on human gingival fibroblasts. The toxic effects should not be assigned to a relevant group of materials, but each dentistry product should be evaluated individually.

A comparative assessment of the antibacterial activityof root canal sealers on 2 Actinomyces species: An in vitro study

BACKGROUND Actinomyces species have a low virulence and pathogenicity, but under specific circumstances they may be involved in root canal and periapical tissue infections. OBJECTIVES The aim of the study was to investigate the antibacterial activity of various root canal sealers on standardized strains of Actinomyces. MATERIAL AND METHODS The materials tested in this study included AH Plus™ Jet (AH), Apexit® Plus (AP), Endomethasone N (EN), GuttaFlow® (GF), Hybrid Root SEAL (HB), MTA Fillapex (FL), Real® Seal (RCS), Roeko Seal Automix (RSA), Sealapex™ (SP), and Tubli-Seal™ (TS). The antibacterial effect of the freshly mixed sealers on standardized strains of Actinomyces israelii NCTC 8047 and Actinomyces viscosus ATCC 15987 was evaluated with the use of the agar diffusion test (ADT). The results were obtained by measuring the diameter of the growth inhibition zone at 96 h and 1, 2, 3, and 4 weeks, and were analyzed in time using repeated measures analysis of variance (ANOVA). Statistically significant differences among the materials were determined by using one-way ANOVA and Tukeys post hoc testing. A paired Students t-test was applied to compare the susceptibility of particular strains to each sealer. The critical level of significance for all tests was p < 0.05. RESULTS Most sealers demonstrated growth inhibition zones against both tested bacteria, except for RSA and GF. Actinomyces viscosus was significantly more susceptible than A. israelii to AP, RCS (p < 0.001) and TS (p = 0.012). Actinomyces israelii was significantly more susceptible than A. viscosus to EN, HB and SP (p < 0.001). CONCLUSIONS The antimicrobial effect of the examined materials varied considerably depending on the type of material and bacterial species tested. Most of the tested root canal sealers exhibited antibacterial activity on standardized strains of Actinomyces, with FL showing the highest antibacterial effect on both bacterial strains. Importantly, both standardized strains of Actinomyces were characterized by varied sensitivity to root canal sealers.

In vitro evaluation of the antibacterial effect of various root canal sealers on selected anaerobic bacteria

Aim of the study. To determine and compare the antibacterial activity of various root canal sealers against selected strains of anaerobic bacteria: Fusobacterium nucleatum ATCC 25586, Porphyromonas gingivalis ATCC 33277, Peptostreptococcus anaerobius ATCC 27337. Material and Methods. The materials tested in this study included AH Plus Jet (AH), Apexit Plus (AP), Endomethasone N (EN), Epiphany (EP), GuttaFlow (GF), Roeko Seal Automix (RSA), Sealapex (SP) and Tubliseal (TS). The antibacterial effect of the freshly mixed sealers on the above mentioned strains of bacteria was evaluated with the use of the agar diffusion test. After inoculation with the bacteria and applying the materials, the agar plates were incubated at 37°C for one week in an atmosphere of 5-10% CO2. The results were obtained

Direct Pulp Capping in Primary Molars using Mineral Trioxide Aggregate: An in Vivo Study

OBJECTIVE To do a clinical and radiographic evaluation of the effectiveness of MTA when used as a direct pulp capping material in primary molars. STUDY DESIGN Clinical and radiographic follow-up was performed on 30 primary molars with deep caries lesions in 30 patients from 3 to 9.75 years of age. Pulps exposed during cavity preparation were treated by direct pulp capping with MTA. The follow-up clinical and radiographic examinations were carried out at different time intervals: 6, 7-12, 13-18, 19-24, and >24 months after treatment. RESULTS Twenty-four teeth were evaluated during the entire observation period. Positive clinical and radiographic outcomes were achieved in 19 teeth (13 teeth were saved and 6 were exfoliated). In five teeth, complications were observed only in children under 7 years old. CONCLUSION Based on these clinical and radiographic results, MTA was found to be successful when used as a direct pulp capping material in primary teeth.

Different outcomes of managing severe intruded immature permanent incisors: A report of two cases

This report describes the interdisciplinary management of complete intrusions of the maxillary right central incisors with an immature open apex in 2 different patients of a similar age but with different outcomes. The most likely causes of these differences were: ankylosis; inflammatory root resorption; and the systemic condition of the 2nd patient. A number of preinjury and injury factors have a significant influence on the healing outcome. According to this report, prognosis after intrusive luxation appears to depend not only on the severity of the trauma, stage of root development and treatment method, but also probably on the patient’s systemic condition. Therefore, the patient’s current complex medical history should be taken into consideration as a factor significantly affecting the healing outcome and long-term prognosis.