Pathologies Associated with Second Mandibular Molar Due to Various Types of Impacted Third Molar: A Comparative Clinical Study.

Introduction: Impacted third molars are associated with various degrees of damage to the second molars. The possible complications also include distal cervical caries, root resorption of second molar, periodontal problems, odontogenic cysts, etc. Whether a particular impacted third molar is going to affect second molar depends upon its position and orientation in the bone. Materials and Method: This study was carried out in 418 cases. Three examiners evaluated the patient clinically and radiographically and only those cases were included in this study where at least two observers agreed. A total of 341 cases (163 males and 178 female), age range (15-40 years) with impacted mandibular third molars, were included. Clinically and radiographically, the impacted mandibular third and second molars were evaluated; simultaneously, the prevalence of various pathologies associated with mandibular second molar (dental caries, periodontal pockets, root resorption) due to impacted third molar was also evaluated and compared among various types and positions of impactions. Results: Statistical analysis was carried out using Pearson Chi-square and Asymp. Sig. (two-sided) test. Prevalence of mesioangular impactions was maximum (50.1%). Mesioangular impaction and position B (Pell and Gregory classification) were significantly associated with dental caries (32.20% and 33.90%, respectively), and periodontal pockets were seen higher with position B impactions (26.8%) {horizontal (14.7%), disto-angular (12.10%), vertical (14.5%) mesioangular (16.4%%)} in adjacent mandibular second molar. Root resorption was seen maximally in horizontal impaction (17.30%) with position c type (12.30%). The order of pathologies associated with second molar due to impacted third molar was dental caries (19.9%) > periodontal pockets (15.2%) > root resorption (8.5%). Discussion: Evidence regarding pathologies are associated with second molar due to impacted third molar aids in decision making for surgical removal of third molars. Different types of impaction and the prevalence of pathologies related to them would aid in treatment planning of the impacted tooth as certain types have high probability of pathologies associated.

Tuning the oscillatory dynamics of the Belousov-Zhabotinsky reaction using ruthenium nanoparticle decorated graphene.

The classic Belousov-Zhabotinsky (BZ) reaction, which involves transition metal catalysed redox reactions, represents a family of nonlinear chemical oscillators. Here, we show that it is possible to tune the oscillatory dynamics of the BZ reaction by using a hybrid 2D material, i.e., graphene-based nanosheets decorated with Ru nanoparticles. Specifically, we demonstrate that the frequency of chemical oscillations in a BZ reaction increases, by up to four-fold, when catalyzed by the Ru-graphene nanocomposite. We show that this observed behaviour is attributed to enhanced access to active catalytic sites on Ru nanoparticles, as well as the rapid shuttling of electrons facilitated by the highly conductive graphene platform. We further demonstrate that this enhancement of oscillations facilitated by the graphene platform can be simulated using the Oregonator model. Our numerical simulations reveal a strong correlation between the rate of charge transfer and the frequency of chemical oscillations. This ability of a 2D material, like graphene, to influence the dynamics of an oscillatory chemical reaction, as showcased in this work, is studied for the first time and opens up new avenues to tune the dynamics of chemical oscillators. We anticipate that these findings would enable us to design a variety of intrinsically powered biomimetic systems with controllable dynamic behavior.

Benign Fibrous Histiocytoma: A Rare Case Report and Literature Review.

Fibrous histiocytoma is a benign soft tissue tumour that may present as a fibrous mass anywhere in the human body. The involvement of the oral cavity is extremely rare and very few cases have been reported in literature till date. We here report a case of benign fibrous histiocytoma localized in the oral cavity. The clinical and histological features of the lesion are discussed precisely in the light of a literature review of this pathology in oral cavity.