Histological evaluation of tissue reaction and new bone formation of different calcium silicate-based cements in rats.

BACKGROUND: The purpose of this study was to evaluate the local reactions and new bone formation of rat subcutaneous and bone tissue to different calcium silicate cements. METHODS: In this study, 80 rats were divided into five groups as control, BIOfactor MTA (BIO), NeoMTA Plus (NEO), MTA Repair Hp (REP), Biodentine (DENT) and then into two subgroups according to sacrification times (7, 30 days; n = 8). Polyethylene tubes filled with appropriate materials (test groups); empty tubes (control group) were implanted into the dorsum of each rat subcutaneously. For intraosseous implantation, materials were placed in the cavities created in tibia of rats. Subcutaneous tissue and tibia samples were stained with haematoxylin-eosin and subjected to histopathological analysis. A score (0-3) was used to grade inflammatory reaction and new bone formation. Data were analysed by Kruskal-Wallis and Mann-Whitney U tests (P < 0.05). RESULTS: Inflammatory reaction observed in subcutaneous and intraosseous tissues for 7 days decreased significantly in all groups over time (P < 0.05). It was determined that there was significant increase in new bone formation in REP, BIO, DENT groups over time (P < 0.05). CONCLUSION: Four contemporary bioceramic materials induced local inflammation and tissues changes shortly after subcutaneous implantation, which were reduced over time. In intraosseous implantation, all materials induced new bone formation over time. REGISTRATION NUMBER: ADJ-03-23-0134. © 2023 Australian Dental Association.

Analysis of the bond strength between conventional, putty or resin-modified calcium silicate cement and bulk fill composites.

BACKGROUND: The aim of this study was to evaluate the shear bond strength of three different calcium silicate-based cements (CBCs) with two different bulk-fill composite resins (CRs). METHODS: Plexiglas moulds with a diameter of 4 mm and a thickness of 2 mm were prepared (n = 60). The Biodentine, NeoPutty and MTA Cem LC samples were randomly divided into two subgroups containing 10 samples each. Surfaces of samples were air dried and Single Bond universal adhesive was applied. Cylindrical plastic capsules of 4 mm height and 2 mm inner diameter belonging to Filtek Bulk-fill and EverX Posterior CRs were centred on coating material and polymerized for 20 s. After shear bond strength (SBS) testing, all samples were examined by scanning electron microscopy (SEM) to identify failure patterns. Three samples, one from each group, were prepared to evaluate chemical composition of CBCs and examined with an energy dispersive X-ray spectroscopy for surface elemental analysis. RESULTS: The values obtained from the tests were evaluated as statistically significant (P < 0.05). After SBS testing, the difference between all CBCs was statistically significant in both CRs. CONCLUSION: According to the findings in this study, it was concluded that MTA Cem LC had highest SBS values in both CRs. © 2023 Australian Dental Association.

Microleakage of glass ionomer based restorative materials in primary teeth: An In vitro study.

AIM: Using AutoCAD, we examined the microleakage of dye at the edges of primary-teeth restorations using three glass ionomer-based restorative materials. MATERIALS AND METHODS: A total of 30 extracted noncarious primary molars were used. Class V cavities were adjusted on the buccal surfaces. The teeth were randomly divided into three groups of 10 teeth each as follows: Group A (Ketac Molar), Group B (Photac Fil), and Group C (Dyract XP). All specimens were stored for 24 h at 37°C in distilled water. The teeth were thermocycled 1000 times between 5°C ± 2°C and 55°C ± 2°C before immersion in 0.5% basic fuchsin for 24 h. Two mesiodistal cuts of each tooth were photographed under a stereomicroscope equipped with a digital camera. The dye-infiltrated surface area was measured. Statistical evaluations were performed by the Kolmogorov-Smirnov test, Levene test, one-way analysis of variance, and Tukey's honestly significant difference test. RESULTS: The mean microleakage ratio differed significantly among the groups (P < 0.05). Group C exhibited a significantly smaller area (P < 0.001) than the other groups. Group A had a nonsignificantly higher mean microleakage value than Group B (P > 0.05). CONCLUSIONS: Polyacid-modified composite resin may be a useful restorative material in primary teeth in terms of minimizing microleakage.