Dislodgment Resistance, Adhesive Pattern, and Dentinal Tubule Penetration of a Novel Experimental Algin Biopolymer-Incorporated Bioceramic-Based Root Canal Sealer

The currently available bioceramic-based sealers still demonstrate low bond strength with a poor seal in root canal despite desirable biological properties. Hence, the present study aimed to determine the dislodgment resistance, adhesive pattern, and dentinal tubule penetration of a novel experimental algin-incorporated bioactive glass 58S calcium silicate-based (Bio-G) sealer and compared it with commercialised bioceramic-based sealers. A total of 112 lower premolars were instrumented to size 30. Four groups (n = 16) were assigned for the dislodgment resistance test: control, gutta-percha + Bio-G, gutta-percha + BioRoot RCS, and gutta-percha + iRoot SP, with exclusion of the control group in adhesive pattern and dentinal tubule penetration tests. Obturation was done, and teeth were placed in an incubator to allow sealer setting. For the dentinal tubule penetration test, sealers were mixed with 0.1% of rhodamine B dye. Subsequently, teeth were cut into a 1 mm-thick cross section at 5 mm and 10 mm levels from the root apex, respectively. Push-out bond strength, adhesive pattern, and dentinal tubule penetration tests were performed. Bio-G showed the highest mean push-out bond strength (p < 0.05), while iRoot SP showed the greatest sealer penetration (p < 0.05). Bio-G demonstrated more favourable adhesive patterns. No significant association was noted between dislodgment resistance and dentinal tubule penetration (p > 0.05)

Fracture resistance of over-flared root canals filled with MTA and resin-based material: an in vitro study

Aim: To measure the fracture resistance of over-flared roots filled with a variety of materials (gutta-percha-nano HA, resilon-epiphany, composite and mineral trioxide aggregate - MTA) using the Instron machine test and micro-computed tomography (Micro CT) Scan. In addition, scanning electron microscopy (SEM) images were used to illustrate the type of fracture patterns of the specimens. Methods: One hundred and twenty extracted human mandibular singlerooted premolars were selected. A total of 105 out of the selected teeth were prepared to the working length and over-flared, leaving the apical 5 mm undisturbed. Fifteen samples had no treatment and were used as a positive control group (Group +ve). The 105 test teeth were further divided into 7 groups of 15 samples each. One of the 7 groups was designated as negative control (Group -ve) where teeth were over prepared and left without obturation. Remaining groups were filled with gutta-percha-nanoHA (Group1), gutta-percha-nano HA+composite (Group 2), gutta-percha-nano HA+MTA (Group 3), resilon-epiphany (Group 4), resilon-epiphany+composite (Group 5), and resilon-epiphany+MTA (Group 6). Fracture resistance of all samples was measured using the Instron testing machine. Three samples from each group had the depth of their fracture line measured by Micro CT Scan, and 2 samples from each group had their fracture pattern illustrated using SEM. Results: The highest fracture resistance was observed in Group +ve, followed by Groups 3, 6, 5, 2, 4, 1, and Group -ve, with values (in N) of: 1598 (641.0), 1190.5(424.2), 1164.7 (489.4), 821.2 (220.9), 683.4(179), 658.4 (211.3), 658.4 (99.0), 158.3(49.3), respectively. Statistical analysis for root fracture resistance showed highly significant difference between all groups with p value < 001. Conclusions: Micro CT Scan and SEM analysis indicated the ability of MTA to withstand vertical force

Calcium chloride dihydrate affects the biological properties of white mineral trioxide aggregate on dental pulp stem cells: An in vitro study

Introduction: Biological testing of biomaterials on dental pulp stem cells (DPSCs) is one recent advance in endodontic research. The aim of this study was to compare the cytotoxicity, cell attachment properties, and dentinogenic differentiation potential of extracts of white mineral trioxide aggregate (WMTA)/calcium chloride dihydrate CaCl2.2H2O combination (fast-set WMTA [FS WMTA]) to that of WMTA on DPSCs. Materials and Methods: The cytotoxicity and cell attachment properties were evaluated on DPSCs using methyl-thiazol-diphenyltetrazolium assay and under scanning electron microscope, respectively. After 1, 3, and 7 days of incubation, the expression of four dentinogenic gene markers (BGLAP, DSPP, RUNX2, and SPP1) was examined using the real-time polymerase chain reaction. Mann-Whitney test and one-way analysis of variance were used for statistical analysis (P = 0.05). Results: While WMTA showed favorable cytotoxicity and cell attachment properties, FS WMTA demonstrated severe/moderate cytotoxicity at three successive concentrations (P < 0.05), and the cell attachment properties were less favorable. However, DPSCs treated with FS WMTA extracts showed higher expressions of dentinogenic gene markers than WMTA (P < 0.05). BGLAP and SPP1 were down- and up-regulated in both groups at all-time intervals, respectively. DSPP was upregulated only in WMTA at day 3 compared to days 1 and 7 in FS WMTA. RUNX2 was upregulated at all-time intervals only in FS WMTA. Conclusions: The addition of CaCl2.2H2O increases the cytotoxicity but enhances the dentinogenic differentiation potential of WMTA on DPSCs

Fracture resistance of over-flared root canals filled with MTA and resin-based material: an in vitro study

measure the fracture resistance of over-flared roots filled with a variety of materials (gutta-percha-nano HA, resilon-epiphany, composite and mineral trioxide aggregate - MTA) using the Instron machine test and micro-computed tomography (Micro CT) Scan. In addition, scanning electron microscopy (SEM) images were used to illustrate the type of fracture patterns of the specimens. Methods: One hundred and twenty extracted human mandibular singlerooted premolars were selected. A total of 105 out of the selected teeth were prepared to the working length and over-flared, leaving the apical 5 mm undisturbed. Fifteen samples had no treatment and were used as a positive control group (Group +ve). The 105 test teeth were further divided into 7 groups of 15 samples each. One of the 7 groups was designated as negative control (Group -ve) where teeth were over prepared and left without obturation. Remaining groups were filled with gutta-percha-nanoHA (Group1), gutta-percha-nano HA+composite (Group 2), gutta-percha-nano HA+MTA (Group 3), resilon-epiphany (Group 4), resilon-epiphany+composite (Group 5), and resilon-epiphany+MTA (Group 6). Fracture resistance of all samples was measured using the Instron testing machine. Three samples from each group had the depth of their fracture line measured by Micro CT Scan, and 2 samples from each group had their fracture pattern illustrated using SEM. Results: The highest fracture resistance was observed in Group +ve, followed by Groups 3, 6, 5, 2, 4, 1, and Group -ve, with values (in N) of: 1598 (641.0), 1190.5(424.2), 1164.7 (489.4), 821.2 (220.9), 683.4(179), 658.4 (211.3), 658.4 (99.0), 158.3(49.3), respectively. Statistical analysis for root fracture resistance showed highly significant difference between all groups with p value < 001. Conclusions: Micro CT Scan and SEM analysis indicated the ability of MTA to withstand vertical force

Sealing ability of gutta-percha/Nano HA versus Resilon/Epiphany after 20 months using an electrochemical model – an in vitro study

Aim: To evaluate the sealing ability of gutta-percha-nano-HA and Resilon-Epiphany by electrochemical method and micro-computed tomography (CT) scan at 48 h and 20 months using three different obturation techniques (cold lateral condensation technique, warm vertical condensation - System B, and warm vertical condensation with vibration - Down-Pak). Methods: 150 human mandibular single-rooted premolars were prepared and randomly allocated into 6 groups of 25 specimens each, and filled with either gutta-percha-nano HA or Resilon-Epiphany with the three different obturation techniques (cold lateral, warm vertical - System B, and warm vertical with vibration - Down-Pak). Electrochemical microleakage method was used to measure the microleakage after 48 h and after 20 months, and a micro-CT Scanner 1072 was used to evaluate the quality of obturation after 48 h. Results: Group 6 (Resilon-epiphany/Down-Pak technique) had the highest microleakage value, followed by Group 2 (Gutta-percha-nano HA/ System B technique), Group 4 (Resilon-Epiphany/Lateral condensation technique), Group 3 (Gutta-percha-nano HA/Down-Pak technique), Group 5 (Resilon-Epiphany/System B technique), and Group 1 (Gutta-percha-nano HA/Lateral condensation technique) with the values of 4.69 (6.06) KÙ, 3.88 (2.92) KÙ, 3.77 (3.75) KÙ, 3.38 (3.92) KÙ, 2.64 (2.90) KÙ, and 2.44 (4.34) KÙ, respectively. No significant difference in the quantity of leakage was observed for each root in each group between the two tested filling materials and their sealers (p=0.143). Micro CT scan investigations revealed more micro-voids in the Resilon-Epiphany Group obturated with Down- Pak technique. Conclusions: Nano-hydroxyapatite sealer with gutta-percha filling material provided a reasonable seal compared with Epiphany sealer and Resilon filling material

White mineral trioxide aggregate mixed with calcium chloride dihydrate: chemical analysis and biological properties

Objectives: This study aimed to evaluate the chemical and biological properties of fast-set white mineral trioxide aggregate (FS WMTA), which was WMTA combined with calcium chloride dihydrate (CaCl2·2H2O), compared to that of WMTA. Materials and Methods: Surface morphology, elemental, and phase analysis were examined using scanning electron microscope (SEM), energy dispersive X-ray microanalysis (EDX), and X-ray diffraction (XRD), respectively. The cytotoxicity and cell attachment properties were evaluated on human periodontal ligament fibroblasts (HPLFs) using methyl-thiazol-diphenyltetrazolium (MTT) assay and under SEM after 24 and 72 hours, respectively. Results: Results showed that the addition of CaCl2·2H2O to WMTA affected the surface morphology and chemical composition. Although FS WMTA exhibited a non-cytotoxic profile, the cell viability values of this combination were lesser than WMTA, and the difference was significant in 7 out of 10 concentrations at the 2 time intervals (p < 0.05). HPLFs adhered over the surface of WMTA and at the interface, after 24 hours of incubation. After 72 hours, there were increased numbers of HPLFs with prominent cytoplasmic processes. Similar findings were observed with FS WMTA, but the cells were not as confluent as with WMTA. Conclusions: The addition of CaCl2·2H2O to WMTA affected its chemical properties. The favorable biological profile of FS WMTA towards HPLFs may have a potential impact on its clinical application for repair of perforation defects

Dentinogenic differentiation potential of fast set white portland cements of a different origin on dental pulp stem cells

Background: Advances in endodontic biomaterials are at the forefront of endodontic research. Purpose: This study aimed to compare the dentinogenic differentiation potential of extracts of two formulations (normal and fast set [FS] by the addition of calcium chloride dihydrate (CaCl2.2H2O) of white Portland cements (WPCs) of a different origin (Aalborg, Malaysia, and Egypt) on dental pulp stem cells (DPSCs). Materials and Methods: The material extracts at 12.5 mg/ml were applied on DPSCs cultured in 96‑well plates. After 1, 3, 7 and 14 days of incubation, the RNA was extracted, cDNA was prepared, and the expression of four dentinogenic gene markers (bone gamma‑carboxyglutamate protein, dentin sialophosphoprotein, runt‑related transcription factor 2, and secreted phosphoprotein 1 [SPP1]) was examined using the real‑time polymerase chain reaction. One‑way analysis of variance was used for statistical analysis, and the level of significance was set at 0.05 (P = 0.05). Results: Significant differences were observed between Malaysian WPC (MAWPC) and Egyptian WPC (EGWPC) and FS MAWPC), FS EGWPC in 7 out of 15 and 6 out of 10 comparisons, respectively. While more expressions in EGWPC group were observed in four comparisons and three for MAWPC, all FS formulations showed higher expressions for FS MAWPC compared to FS EGWPC (P < 0.05). The addition of CaCl2.2H2O to MAWPC and EGWPC increased the upregulation of SPP1 gene at all‑day intervals, which was not observed with other genes. Conclusions: The dentinogenic differentiation of DPSCs shows different expression profiles to extracts of normal and fast formulations of WPC. Extracts of WPC of different origin have different dentinogenic differentiation potential on DPSCs. Keywords: Calcium chloride dihydrate, dentinogenic differentiation, Egypt, Malaysia, real‑time polymerase chain reaction, white Portland cemen

Chemical analysis and biological properties of two different formulations of white portland cements

White Portland cement (WPC) has generated research interests in the field of endodontics. This study compared between the properties of two formulations of white Portland cement (WPC) of different origin (Malaysia [MA] and Egypt [EG]). WPCs with and without calcium chloride dihydrate were prepared. Scanning electron microscope (SEM), energy dispersive X-ray micro-analysis, and X-ray diffraction were used for surface morphology evaluation, elemental, and phase analysis, respectively. After the preparation of optimized serial dilutions, the cytotoxicity was evaluated on human periodontal ligament fibroblasts (HPLFs) and dental pulp stem cells (DPSCs) using methyl-thiazol-diphenyltetrazolium assay after 24 and 72 h. Cell attachment properties were examined under SEM after 24 and 72 h. Results showed that the surface morphology and chemical composition of both formulations demonstrated detectable variations. The cytotoxicity evaluation showed different cellular responses of HPLFs compared to DSPCs. Both formulations favored the viability of HPLFs. However, the fast set formulations demonstrated severe cytotoxicity on DPSCs. Significant differences between EGWPC and MAWPC were identified (p < 0.05). The cell attachment properties were favorable; however, HPLFs attached and spread over the samples better than DPSCs. In conclusion, WPC of different origin may show differences in chemical and biological properties. The addition of CaCl2 ·2H2 O to WPC can affect its properties. Human cell types may react differently towards different formulations of WPCs. SCANNING 9999:1-14, 2015. © 2015 Wiley Periodicals, Inc