Microscopic qualitative evaluation of fixation time and decalcification media in rat maxillary periodontium

The rat model is widely used in periodontal research and the quality of histological sections is essential. The purpose of this study was to evaluate the histological characteristics of periodontal tissues in Wistar rat maxillae, with different times of fixation and decalcified by nitric acid or formic acid (Anna Morse Solution). Fifteen rats were used. Fixation was performed for 24, 48 and 72 hours. The maxillae were hemi-sectioned and each part was decalcified either in nitric acid for 7 days or in Anna Morse solution for 35 days. Two trained and blinded examiners performed the evaluation. Fourty eight hours of fixation and decalcification with Anna Morse solution showed more clear characteristics of the epithelium-connective tissue interface and of the periodontal structures. Mean measurements between the cementum-enamel junction and the bone crest varied in the different experimental times from 176.5 (+/- 60.45) to 210.94 (+/- 39.33) pixels on the buccal aspect, and from 199.69 (+/- 38.33) to 298.55 (+/-70.81) pixels on the palatal aspect, with no statistically significant differences (ANOVA, p > 0.05). In the same fixation period, decalcification with nitric acid or Anna Morse solution did not display any statistically significant differences. It may be concluded that for a qualitative histological analysis, fixation should preferably be for 48 hours and the demineralization should be made by Anna Morse solution. For a histomorphometric analysis, the decalcification solution does not interfere in the results.     

Oral fluoride retention in saliva following toothbrushing with child and adult dentifrices with and without water rinsing

Ten healthy adult volunteers were recruited to participate in this double-blind randomised 18-leg crossover designed study. The subjects either rinsed their mouth with 10 ml de-ionised distilled water for 10 s or just spat out once after 1-min brushing with one of nine different toothpastes: NaF (500, 1,000 and 1,450 ppm F), SMFP (525, 1,000, 1,450 ppm F), AmF (250, 1,400 ppm F) or fluoride-free dentifrice. Samples of whole mixed unstimulated saliva were collected at different time intervals. The results showed that the use of the AmF toothpaste (1,400 ppm F) resulted in the highest fluoride content of saliva without water rinsing after 120 min (0.52 ppm F, CI 0.23, 0.81). Two hours after brushing with fluoride toothpaste containing AmF and NaF, the salivary fluoride levels were still higher than baseline levels.     

Potential Remineralization of Postorthodontic Demineralized Enamel and the Use of Enamel Microabrasion and Bleaching for Esthetics

Prevention of enamel demineralization during orthodontic treatment is of utmost importance. Should enamel demineralization occur (white spot lesions), early diagnosis and intervention is appropriate. Improved brushing with fluoridated dentifrice and over-the-counter fluoride rinses would be the first recommended intervention. If more aggressive intervention is considered to be necessary due to the extent of demineralized enamel or expected noncompliance with oral hygiene by the patient, professionally applied and/or prescribed fluorides are recommended. Likewise, casein phosphopeptide-amorphous calcium phosphate systems have demonstrated remineralization effects.     

Bacterial leakage along the implant-abutment interface of premachined or cast components

In recent clinical studies, contamination of the inner parts of dental implants through bacterial penetration along the implant components has been observed. The aim of the present in-vitro study was to investigate leakage of Fusobacterium nucleatum through the interface between implants and premachined or cast abutments. Both premachined (n=10) and cast (n=10) implant-abutment assemblies were inoculated with 3.0 microL of microbial inoculum. The assemblies were completely immersed in 5.0 mL of tryptic soy broth culture medium to observe leakage at the implant-abutment interface after 14 days of anaerobic incubation. Bacterial growth in the medium, indicative of microbial leakage, was found only in 1 out of 9 samples (11.1%) in each group. Both premachined and cast abutments connected to external hexagonal implants provide low percentages of bacterial leakage through the interface in in vitro unloaded conditions if the manufacturer's instructions and casting procedures are properly followed.     

Regulatory T cells for tolerance

Regulatory T cells (Tregs) are critical mediators of immune homeostasis and hold significant promise in the quest for transplantation tolerance. Progress has now reached a critical threshold as techniques for production of clinical therapies are optimised and Phase I/II clinical trials are in full swing. Initial safety and efficacy data are being reported, with trials assessing a number of different strategies for the introduction of Treg therapy. It is now more crucial than ever to elucidate further the function and behaviour of Tregs in vivo and ensure safe delivery. This review will discuss the current state of the art and future directions in Treg therapy.     

Mechanisms of COVID-19-induced kidney injury and current pharmacotherapies

The COVID-19 pandemic created a worldwide debilitating health crisis with the entire humanity suffering from the deleterious effects associated with the high infectivity and mortality rates. While significant evidence is currently available online and targets various aspects of the disease, both inflammatory and noninflammatory kidney manifestations secondary to COVID-19 infection are still largely underrepresented. In this review, we summarized current knowledge about COVID-19-related kidney manifestations, their pathologic mechanisms as well as various pharmacotherapies used to treat patients with COVID-19. We also shed light on the effect of these medications on kidney functions that can further enhance renal damage secondary to the illness.

     

Excellent Results and Minimal Complications of Total Hip Arthroplasty in Sickle Cell Hemoglobinopathy at Mid-Term Follow-Up Using Cementless Prosthetic Components

The purpose of this study was to compare the outcomes of cementless primary total hip arthroplasty (THA) in sickle cell patients compared to the remaining cohort of osteonecrosis patients who did not have this disease. Thirty-two sickle cell patients (42 hips) who had a mean age of 37 years and mean follow-up of 7.5 years (range, 5–11 years) were compared to 87 non-sickle cell osteonecrosis patients (102 hips) who had mean age of 43 years and mean follow-up of 7 years (range, 3–10.5 years). Outcomes evaluated included implant survivorship, Harris hip scores, complication rates, radiographic outcomes, and Short Form-(SF-36) health questionnaire. There were no significant differences in aseptic implant survivorship (95 vs. 97%), Harris hip scores (87 vs. 88 points), SF-36 score, or radiographic findings between the two patient cohorts. In light of these findings, we believe that the outcomes of THA improved in sickle cell patients with optimized medical management and the use of cementless prosthetic devices.