A Systematic Review and Meta-Analysis Comparing Surgical and Nonsurgical Treatments for Excessive Gingival Display.

Excessive gingival display (EGD) is defined as more than 2 mm of gingiva display above the maxillary incisors at maximum smile. Various skeletal, dental, and soft tissue etiological factors for EGD have been suggested. This study assessed the effectiveness and stability of surgical (SX) and nonsurgical (NSX) interventions for correction of EGD through a systematic review and meta-analysis following PRISMA 2020 guidelines. An electronic search of Ovid MEDLINE, EMBASE, CENTRAL, Scopus, Web of Science, and LILACS was conducted (2010-2023). Results were expressed as mean change in gingival display using the random-effects model at 1, 3, 6, and 12-month follow-up. At 1 month, SX and NSX treatments yielded a comparable mean reduction of 3.50 mm (2.13-4.86) and 3.43 mm (2.67-4.19) in gingival display, respectively. However, by 6 months, NSX treatments showed a reduction of 0.51 mm compared to 2.86 mm with SX treatments. SX outcomes remained stable past 6 months, while NSX outcomes partially relapsed at 6 months and returned to baseline levels at 12 months. Notably, NSX treatments were more effective in cases with mild initial EGD, while SX treatments showed a better outcome in severe cases. To draw more robust conclusions regarding the treatment outcomes, future primary studies of greater rigor are required.

Myricetin-induced oxidative stress suppresses murine T lymphocyte activation.

A number of polyphenolic compounds present in fruits and vegetables have the capacity to modulate immune responses; however, the impact of the common plant-derived flavonoid myricetin on T lymphocyte function has not been investigated. We show that myricetin inhibited mouse T lymphocyte activation by bead-immobilized anti-CD3 and anti-CD28 monoclonal antibodies, as indicated by a dose-dependent reduction in cell proliferation and decreased synthesis of interferon-γ, interleukin (IL)-2, IL-4, and IL-17 associated with different T helper cell subsets. This effect was attributed to myricetin-induced reactive oxygen species (ROS) since myricetin caused hydrogen peroxide (H2 O2 ) to accumulate in cell-free culture medium and H2 O2 inhibited T cell proliferation and cytokine synthesis. In addition, the antioxidant N-acetyl cysteine restored the ability of myricetin-treated T lymphocytes to proliferate in response to a mitogenic stimulus. The presence of dendritic cells or bone marrow-derived macrophages negated the inhibitory effect of myricetin on T cell activation, and H2 O2 in T cell cultures that were treated with exogenous H2 O2 was reduced when antigen-presenting cells were also present. These findings suggest that antioxidant molecules produced by dendritic cells and macrophages protected T cells from myricetin-induced oxidative stress, and underscore the importance of considering immune cell interactions when evaluating the immunomodulatory activity of ROS-generating phytochemicals.

Effect of Different Disinfection/Sterilization Methods on Risk of Fracture of Teeth Used in Preclinical Dental Education.

The aim of this in vitro study was to determine whether different disinfection/sterilization methods affected the risk of fracture of extracted teeth used for preclinical dental education. Freshly extracted intact mandibular incisors were assigned to different groups according to the processing method used. In the autoclave group (n=20), teeth were autoclaved for 40 min at 240°F under a pressure of 20 psi; in the formalin group (n=20), teeth were immersed in 10% formalin for two weeks; and in the control group (n=10), teeth were not processed. Teeth were then stored at 4°C in distilled water until use. Endodontic procedures were performed, and the fracture strength of the specimen was subsequently tested under compressive force along the long axis of the teeth using an Instron universal testing machine. The results showed that none of the specimens fractured during endodontic procedures. However, the compressive load needed to fracture the teeth was significantly less for the autoclaved teeth than the teeth stored in formalin or the control teeth (p<0.001). The disinfection/sterilization method used affected the fracture resistance of extracted teeth: autoclaved teeth were less resistant to fracture than teeth that were not sterilized or teeth that were chemically disinfected. However, fracture resistance was not reduced enough to lead to tooth fracture during preclinical endodontic procedures. Therefore, either processing method may be appropriate for teeth to be used for preclinical endodontic training.