Biocompatibility of Portland Cement Modified with Titanium Oxide and Calcium Chloride in a Rat Model

Subcutaneous Tissue Response to Adseal and Sure-Seal Root Sealers in Rats: a Histopathological Study

Introduction and objectives: One of the essential phases of root canal treatment is root canal obturation. Solid or semi-solid materials are the most common obturating materials (paste or softened form). Sealer is a biomaterial that enables the sealing process to be carried. This study aimed to evaluate the inflammatory response to Adseal sealer and Sure-Seal Root sealer in rats. Materials and methods:This experimental study was conducted on 28 Wistar rats that were divided into four groups of seven animals per group based on four time periods (7, 14, 30 and 60 days). Each rat received subcutaneous implants containing Adseal sealer (Meta Biomed, Cheongju, Korea) and Sure-Seal Root sealer (Sure Dent Corporation, Gyeonggi-do, South Korea) tubes as well as an empty tube as a control. After the insertion of the tubes, the first to fourth groups were sacrificed on days 7, 14, 30 and 60, respectively, by injecting a high dose of anesthetics. Subsequently, the histopathologic features of the samples were investigated. Data were analyzed in SPSS software (version 26) using Freidman, Wilcoxon, Kruskal-Wallis and Mann-Whitney U tests. A p-value less than 0.05 was considered statistically significant. Results:On day 7, the severity of inflammation was higher in the Adseal sealer and Sure-Seal Root sealer groups compared to the control group. Moreover, on day 14, the level of inflammation was higher in the Sure-Seal Root sealer group than the Adseal sealer and control groups. In addition, on days 30 and 60, the severity of inflammation was similar in both the case and control groups and decreased in all samples. Formation of granulation tissue was observed in all samples on day 14. There was fibrosis tissue in the Sure-Seal Root sealer samples (71.4%) on day 60; however, no fibrosis tissue was observed in the Adseal sealer and control groups. Conclusion:It is concluded that the Sure-Seal Root sealer might lead to a more inflammatory response compared to the Ad Seal sealer. However, due to decreasing inflammation in sealers over time, both sealers are biocompatible.

Comparison of Rat Connective Tissue Response to BioMTA, Angelus MTA, and Root MTA

Due to the widespread use of MTA in dentistry and various brands of this product, we decided to compare the three brands available in the country market by their biocompatibility. We divided 20 male Wistar rats into four groups. After local anesthesia and washing, we made two incisions on both sides (4 incisions in total). The experimental groups were Angelus MTA (Angelus, Brazil), BioMTA (CERKAMED, Poland), Root MTA (Dr. Lotfi, Tabriz, Iran), and the control group. The resulting paste was placed in a tube and implanted subcutaneously into male Wistar rats. Wistar rats were sacrificed 7, 15, 30, and 60 days later, with high anesthetic doses. The sample implanted in 10% formalin was stabilized after tissue processing and H&E staining under a microscope. The inflammatory reaction in the tissues received different scores at the beginning of the tube opening. BioMTA had the highest inflammatory response among the groups, but the difference was not statistically significant (p > 0.05). Also, there was no significant difference between the groups' granulation and calcification (p < 0.05). There was a significant difference between BioMTA, Angelus MTA, Root MTA, and control groups in fibrous capsule formation (p < 0.05). Angelus MTA showed the lowest mean fibrous capsule formation in all periods. The effects of Angelus MTA, Root MTA, and BioMTA on connective tissue were investigated and compared. According to this study, these materials have good biocompatibility. According to the findings and statistical analysis, Angelus MTA has the most biocompatibility.

Effect of Biotitania and Titania Addition on Bioactivity and Antibacterial Properties of Calcium Silicate Cement

Introduction

Nanoparticles are gaining more interest in dentistry for their antimicrobial, physical as well as other properties. This study aimed to evaluate the effect of adding two types of nanoparticles (NPs) on calcium silicate hydraulic cement's (CSHC) unique bioactivity and antibacterial properties.

Methods and Materials

Biotitania/AgCl NPs were synthetized and characterized for its morphology, types of formed functional groups and crystalline AgCl using field emission scanning electron microscope (FE-SEM) equipped with energy-dispersive X-ray spectroscopy (EDS), X-ray diffractometer (XRD), Fourier transformation infrared spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA). The former NPs and commercial titania (TiO2) NPs were added (0.5, 1.5 and 3-weight %) to commercial CSHS powder. A total of 140 disk-shaped specimens (10 mm×1 mm) were prepared (seven material groups per each test in addition to the eighth cell control group) to evaluate cell viability and alkaline phosphatase activity (ALP) after 3 and 12 days, respectively. All were incubated with mesenchymal stem cells. Antibacterial efficacy against Streptococcus mutans (S. mutans) was evaluated through the bacterial growth curve slopes while being in direct contact with the tested material groups for 18 h. One-way analysis of variance (ANOVA) and post hoc Tukey's tests were used to analyze the obtained data.

Results

Addition of all NPs percentages had no significant effect (P 0.05) on cell viability in comparison to positive control CSHC. Commercial TiO2 NPs (0.5 weight %) had statistically significant lower values (P≤0.05) for bacterial growth curve slope. However, addition of all NPs percentages had significantly improved (P≤0.05) the ALP activity of CSHC with the most prominent effect to 3-weight% biotitania/AgCl NPs.

Conclusion

Based on this in vitro study, addition of biotitania/AgCl NPs up to 3-weight% significantly improved the bioactivity of CSHC without having a significant negative impact on its antibacterial efficacy. Interestingly, the addition of commercial TiO2 even in small amounts can significantly improve CSHC antibacterial efficacy.