Dental discoloration caused by Grey-MTAFlow cement: analysis of its physicochemical, biological and antimicrobial properties

Tricalcium silicate-based cement are materials used in reparative and regenerative procedures in endodontics. A recently proposed formulation aimed to enhance handling during clinical use with a versatile material applicable by syringe. Although, the use of bismuth oxide as radiopacifier and grey raw powder are drawbacks considering aesthetics. Objectives: Evaluate physicochemical, biological, and antimicrobial properties of Grey-MTAFlow (Ultradent) and assess whether the addition of zinc oxide (ZnO) prevents dentinal discoloration caused by bismuth oxide. Methodology: Grey-MTAFlow was manipulated in 'thin' consistency for all tests. Luminosity, color change, ion migration to dentine, radiopacity, setting time, ISO 6876:2012 linear flow, volumetric lateral flow and central filling of simulated grooves scanned using micro-computed tomography (μCT), pH, calcium release, volumetric change using μCT, chemical characterisation, cytotoxicity, and antimicrobial activity were assessed. Addition of 5% ZnO to Grey-MTAFlow and a bismuth-containing experimental composition were comparatively tested. Statistical analyses used Shapiro-Wilk, T-test, ANOVA, and Kolmogorov-Smirnov (p<0.05). Results: The addition of ZnO to Grey-MTAFlow prevented dentine darkening after 90 days due to bismuth migration reduction, although no statistical difference was found (p=0.863). ZnO addition significantly enhanced Grey-MTAFlow radiopacity without differences in initial setting time. Grey-MTAFlow presented an ISO linear flow of 10.9 mm and a balanced volumetric lateral flow with central filling in μCT evaluation. All compositions presented an alkaline pH after immersion. Grey-MTAFlow had a significantly higher calcium ion release after 28 days in comparison to 24 hours (p=0.011) and volumetric expansion of 0.4±1.8% after immersion. ZnO addition altered the hydrated cement matrix once calcium hydroxide (portlandite) could not be detected in characterisation. Neither of the materials produced inhibition halos nor reduced bacterial turbidity, but all presented cytocompatibility above 100%

Can strontium replace calcium in bioactive materials for dental applications?

The substitution of calcium with strontium in bioactive materials has been promising but there has been some concern over the material instability and possible toxicity. The aim of this research was the synthesis and characterization of calcium and strontium substituted bioactive materials and assessment of interactions with local tissues and peripheral elemental migration in an animal model. A bioactive glass, hydroxyapatite and hydraulic calcium silicate with 50% or 100% calcium substitution with strontium were developed and the set materials were characterized immediately after setting and after 30 and 180‐days in solution. Following subcutaneous implantation, the local (tissue histology, elemental migration) and systemic effects (elemental deposition after organ digestion) were assessed. The strontium‐replaced silicate cements resulted in the synthesis of partially substituted phases and strontium leaching at all‐time points. The strontium silicate implanted in the animal model could not be retrieved in over half of the specimens showing the high rate of material digestion. Tissue histology showed that all materials caused inflammation after 30 days of implantation however this subsided and angiogenesis occurred after 180 days. Strontium was not detected in the local tissues or the peripheral organs while all calcium containing materials caused calcium deposition in the kidneys. The tricalcium silicate caused elemental migration of calcium and silicon in the local tissues shown by the elemental mapping but no deposition of calcium was identified in the peripheral organs verified by the assessment of the digested tissues. Strontium can substitute calcium in bioactive materials without adverse local or systemic effects

Acute Odontogenic Maxillary Sinusitis Treated Endodontically Two Case Reports and 15-day CBCT outcome

s presented acute recurrences from Otorhinolaryngology treatments with unilateral symptoms compatible with maxillary sinusitis with a dental origin (MSDO). Cone beam computed tomography (CBCT) showed sinus extensive membrane thickening that was not visible at periapical exam associated to the maxillary molar infection in both cases. Respiratory structures assessment was possible using a 6-inches field of view CBCT. Non-surgical endodontic treatment (case 1) performed and retreatment (case 2) showed a fast symptoms relief. Recall examination after 15 days revealed healthy soft tissues with normal periodontal probing and no dental mobility. In addition, 15-day CBCTs revealed initial maxillary sinus membrane recovery after the endodontic approaches in the reported cases. No additional medical intervention nor antibiotics administration were necessary in these MSDO cases management. Long-term follow-up in such cases is advisable to exclude other potential dental or respiratory issues. Diagnose and follow-up using CBCT presented significant sinus membrane thick reduction with no symptoms recurrence after the endodontic treatment

Anxiety immediately before endodontic treatment: cross-sectional quantitative analysis

Abstract Introduction Endodontic treatments are considered by the patients to be one of the most painful and anxiety-generating procedures and this feeling may be linked to both environmental and individual aspects. This study aimed to evaluate the degree of anxiety of patients immediately before the endodontic treatment. Methods The study design was a cross-sectional quantitative analysis where patient sampling was performed on those who met the inclusion criteria and needed endodontic treatment. The interview instruments for the investigation were a questionnaire with semi-structured questions, the Corah Dental Anxiety Scale, and a digital device for measurement of blood pressure and heart rate. The variables investigated were gender, age, whether the patient liked to visit the dentist, depression, whether the patient used medication for depression, systolic and diastolic pressure, and heart rate. Data statistical were analysed using descriptive statistics and to evaluate the association between variables Pearson’s chi-square tests were used with a significance level of 5%. Results 175 patients were included in the study and categorized as little anxious (33.7%), mildly anxious (45.1%), moderately anxious (15.4%), and extremely anxious (5.7%). There was a strong association between higher degrees of anxiety and whether the patient declared not liking to visit the dentist; no other significant correlation was found. Conclusion Endodontic patients who claim not to like to visit the dentist are more anxious. Healthcare professionals can pursue strategies to treat these patients with anxiety reduction techniques avoiding the postponement or evasion of endodontic treatments

Protocol for subcutaneous implantation of polyethylene tubes containing endodontic reparative materials in 12-week-old Wistar rats

The subcutaneous implantation of filled polyethylene tubes is traditionally used to investigate local biological responses to a material placed within this type of tube. An extensive report regarding this implantation technique in the 1960’s validated this type of implantation since their results indicated that “after 60 days of implantation the tubes were surrounded by a noninflamed connective tissue capsule”. Thus, a potential tissue reaction (i.e., inflammation) to an implanted filled tube could be attributed to the material/substance within the tube. However, it is crucial to include in the experimental setup empty tubes to be implanted similarly, serving as controls. Here, we describe a protocol for tube implantation used to investigate in vivo the tissue response to implanted polyethylene tubes containing calcium silicate-based materials. The expected results following these implantations include qualitative histological analysis and, additionally, quantitative data from score analysis are also obtainable