Portland Cement: An Overview as a Root Repair Material

Assessment of sealing efficacy, radiopacity, and surface topography of a bioinspired polymer for perforation repair

Background

Root perforation repair presents a significant challenge in dentistry due to inherent limitations of existing materials. This study explored the potential of a novel polydopamine-based composite as a root repair material by evaluating its sealing efficacy, radiopacity, and surface topography.

Methods

Confocal microscopy assessed sealing ability, comparing the polydopamine-based composite to the gold standard, mineral trioxide aggregate (MTA). Radiopacity was evaluated using the aluminium step wedge technique conforming to ISO standards. Surface roughness analysis utilized atomic force microscopy (AFM), while field emission scanning electron microscopy (FESEM) visualized morphology.

Results

The polydopamine-based composite exhibited significantly superior sealing efficacy compared to MTA (P < 0.001). Radiopacity reached 3 mm aluminium equivalent, exceeding minimum clinical requirements. AFM analysis revealed a smooth surface topography, and FESEM confirmed successful composite synthesis.

Conclusion

This study demonstrates promising properties of the polydopamine-based composite for root perforation repair, including superior sealing efficacy, clinically relevant radiopacity, and smooth surface topography. Further investigation is warranted to assess its clinical viability and potential translation to endodontic practice.

Biocompatibility of mineral trioxide aggregate and biodentine as root-end filling materials: an in vivo study

This study evaluated the biocompatibility of mineral trioxide aggregate (MTA) and Biodentine (BD) as root-end filling materials. Six mongrel dogs were divided into two equal groups according to the evaluation period; group A: one month and group B: three months. Three premolars of the same quadrant in each arch were used, summing up 36 teeth (6 teeth/dog). These teeth were randomly subdivided into three subgroups according to the root-end filling material used: MTA, BD and no root-end filling material (control). Endodontic access cavities were performed for induction of periapical pathosis. After the infection period, root canal instrumentation and obturation were accomplished. One day after root canal procedures, root-end surgery was performed. Surgical access was achieved and the root-end was resected approximately 3 mm above the apex. Root-end cavity was prepared ultrasonically and filled with the tested materials. All samples were evaluated by radiography and histopathology (Inflammation and new hard tissue formation). Data were collected and subjected to statistical analysis. In group A, MTA subgroup exhibited significant higher mean inflammatory score than BD subgroup (P < 0.05) while no significant difference was recorded between MTA and BD subgroups in group B (P > 0.05). Regarding mean mineralization score, there was no significant difference between all subgroups in both groups A and B (P > 0.05). Biodentine exhibited favorable biocompatibility in the initial stage of healing than MTA and comparable biomineralization. Clinical relevance: Biodentine could be considered as an acceptable alternative to MTA in peri-radicular surgeries.

Comparative Evaluation of Shear Bond Strength of Resin-modified Glass Ionomer Cement with ProRoot MTA and MTA Angelus

AIM

The aim of the present study was to evaluate the shear bond strength of resin-modified glass ionomer cement with two different types of mineral trioxide aggregate at different time intervals.

MATERIALS AND METHODS

A total of 80 cylindrical blocks were prepared using a self-cure acrylic resin with a central cavity of 4 mm internal diameter and 2 mm height. The prepared samples were randomly divided into two groups (n = 40 each) according to the type of MTA cements used (ProRoot MTA and MTA Angelus). Two groups were further sub-divided into four sub-groups of 10 samples each according to the different time intervals. ProRoot MTA and MTA Angelus were placed in the prepared cavity and a wet cotton pellet was placed over the filled cavity. A hollow plastic tube was placed over the MTA surface and resin-modified glass ionomer cement (RMGIC) was placed into the hollow plastic tube and light-cured (Spectrum 800, Dentsply Caulk Milford, DE, USA) according to the time intervals decided. After light curing the plastic tubes were removed carefully and the specimens were stored at 37°C and 100% humidity for 24 hours to encourage setting of MTA. The specimens were mounted in a universal testing machine (ADMET) and a crosshead speed of 0.5 mm/min was applied to each specimen by using a knife-edge blade until the bond between the MTA and RMGIC failed. The data were statistically analyzed using ANOVA, post hoc Tukey's t-test and Fisher's t-test and p-value ≤ 0.5 was considered significant.

RESULTS

For both ProRoot MTA and MTA Angelus there was no statistically significant difference between 45 minutes and 24 hours (p-value ≥ 0.8). For ProRoot MTA, shear bond strength value at 10 minutes were significantly lower than 45 minutes and 24 hours group. However, for MTA Angelus, shear bond strength value at 10 minute was not significantly different from 45 minutes group (p-value ≥ 0.3). For both ProRoot MTA and MTA Angelus shear bond strength value at 0 minute were the least and were significantly lower than 10 minutes, 45 minutes, and 24 hours, respectively (p-value ≥ 0.000).

CONCLUSION

Resin-modified glass ionomer cement can be layered over MTA Angelus after it is allowed to set for 10 minutes. However, ProRoot MTA should be allowed to set for at least 45 minutes before the placement of RMGIC to achieve better shear bond strength.

CLINICAL SIGNIFICANCE

Due to the variety of types of mineral trioxide aggregate cements available in dentistry, it is justifiable to emphasize on different time intervals as it may affect the shear bond strength of restorative cements. Such information is pivotal for the clinicians while using mineral aggregate-based cements that receive forces from the condensation of restorative materials or occlusion, as the compressive strength may be affected due to different time intervals. How to cite this article: Tyagi N, Chaman C, Anand S, et al. Comparative Evaluation of Shear Bond Strength of Resin-modified Glass Ionomer Cement with ProRoot MTA and MTA Angelus. J Contemp Dent Pract 2024;25(1):35-40.

Advances and challenges in regenerative dentistry: A systematic review of calcium phosphate and silicate-based materials on human dental pulp stem cells

Conventional dentistry faces limitations in preserving tooth health due to the finite lifespan of restorative materials. Regenerative dentistry, utilizing stem cells and bioactive materials, offers a promising approach for regenerating dental tissues. Human dental pulp stem cells (hDPSCs) and bioactive materials like calcium phosphate (CaP) and silicate-based materials have shown potential for dental tissue regeneration. This systematic review aims to investigate the effects of CaP and silicate-based materials on hDPSCs through in vitro studies published since 2015. Following the PRISMA guidelines, a comprehensive search strategy was implemented in PubMed MedLine, Cochrane, and ScienceDirect databases. Eligibility criteria were established using the PICOS scheme. Data extraction and risk of bias (RoB) assessment were conducted, with the included studies assessed for bias using the Office of Health and Translation (OHAT) RoB tool. The research has been registered at OSF Registries. Ten in vitro studies met the eligibility criteria out of 1088 initial studies. Methodological heterogeneity and the use of self-synthesized biomaterials with limited generalizability were observed in the included study. The findings highlight the positive effect of CaP and silicate-based materials on hDPSCs viability, adhesion, migration, proliferation, and differentiation. While the overall RoB assessment indicated satisfactory credibility of the reviewed studies, the limited number of studies and methodological heterogeneity pose challenges for quantitative research. In conclusion, this systematic review provides valuable insights into the effects of CaP and silicate-based materials on hDPSCs. Further research is awaited to enhance our understanding and optimize regenerative dental treatments using bioactive materials and hDPSCs, which promise to improve patient outcomes.

Ex Vivo Osteogenesis Induced by Calcium Silicate-Based Cement Extracts

Calcium silicate-based cements are used in a variety of clinical conditions affecting the pulp tissue, relying on their inductive effect on tissue mineralization. This work aimed to evaluate the biological response of calcium silicate-based cements with distinct properties-the fast-setting Biodentine™ and TotalFill^® BC RRM™ Fast Putty, and the classical slow-setting ProRoot^® MTA, in an ex vivo model of bone development. Briefly, eleven-day-old embryonic chick femurs were cultured for 10 days in organotypic conditions, being exposed to the set cements' eluates and, at the end of the culture period, evaluated for osteogenesis/bone formation by combining microtomographic analysis and histological histomorphometric assessment. ProRoot^® MTA and TotalFill^® extracts presented similar levels of calcium ions, although significantly lower than those released from Biodentine^TM. All extracts increased the osteogenesis/tissue mineralization, assayed by microtomographic (BV/TV) and histomorphometric (% of mineralized area; % of total collagen area, and % of mature collagen area) indexes, although displaying distinct dose-dependent patterns and quantitative values. The fast-setting cements displayed better performance than that of ProRoot^® MTA, with Biodentine^TM presenting the best performance, within the assayed experimental model.

Cell viability and physicochemical effects of different concentrations of bismuth trioxide in a mineral trioxide aggregate cement

PURPOSE

To evaluate the effect of three concentrations of bismuth trioxide (Bi₂O₃) on the biological and physicochemical properties of an experimental mineral trioxide aggregate-type (MTA-type) cement at different time points.

METHODS

Three experimental groups with white Portland cement containing 15, 20, or 25 wt% of Bi₂O₃ were assessed. Cellular proliferation in human periodontal ligament fibroblasts was evaluated with an MTT assay. Radiopacity, dimensional stability, pH, and compressive strength were evaluated at different time points.

RESULTS

Bismuth trioxide induced cell proliferation in the Bi15 and Bi25 groups in a time-dependent manner; pH was similar in all groups. Compressive strength was associated with time and bismuth concentration. Bi25 had significantly contracted at day 7 and expanded at day 14 (ANOVA P < 0.05, post hoc Tukey test P < 0.05).

CONCLUSION

A higher Bi₂O₃ concentration had a negative effect on the physical properties of the cement at all time points.

Comparison of the Effects of TheraCal LC and Mineral Trioxide Aggregate on Direct Pulp Capping (DPC) Based on Histological Findings

Background: Direct pulp capping can conserve its vitality by placing materials that promote dentin bridge (DB) formation at the exposure site. This study aimed to determine whether TheraCal LC could produce a layer of reparative dentin. It also compared the histological differences between treatment with mineral trioxide aggregate (MTA) and TheraCal LC.

Material and methods: A sample of 20 maxillary and mandibular premolars, which had previously been indicated for extraction in orthodontic therapy, was taken from 10 patients and randomly divided into two halves, a TheraCal LC, and an MTA group. Pulpal exposure was achieved by similar class I preparations, which were restored with a resin-modified glass-ionomer and extracted after ten weeks, noting that these interventions have been performed on live teeth in the oral cavities. The newly formed dentin bridge thickness, the inflammation degree within the pulp tissue, and odontoblast function were thoroughly examined histologically and compared between the two groups using the Mann-Whitney test and an analysis software SPSS (statistical package for the social sciences, v.26, IBM, New York, N, USA), at a significance level of a=0.05.

Results: Dentin bridge composition in the TheraCal group had 80% effective tubules and 20% defective tubules, while in the MTA group, the proportions were 90% and 10%, respectively. Dentin bridge thickness in the TheraCal group was greater than 0.25 mm in 60%, and 0.1-0.25 mm in 40% of the sample compared to the MTA group, which had 70% greater than 0.25 mm, and 30% between 0.1 and 0.25 mm in dentin bridge thickness. Statistically, there was no significant difference between both groups (P=0.739).

Conclusion: Statistically insignificant differences in dentin bridge composition and thickness produced by both TheraCal and MTA materials render them similar in their effectiveness in treating pulp exposures through pulp capping.