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Aim: To evaluate the effect of prosthetic framework material and cantilever length on peri-implant strain in mandibular all-on-four implant-supported prostheses with different types of arch antagonist forces. Materials and Methods: Models simulating a completely edentulous mandibular arch fabricated in heat-cured acrylic resin were used. On the acrylic models, four implants were placed at regions 34, 32, 42, and 44 simulating all-on-four implant placements. Implant-supported screw-retained fixed prosthesis frameworks were fabricated using three different materials (cobalt-chromium, zirconia, and polyetheretherketone) and with three different cantilever lengths (zero mm, 15 mm, and 25 mm). Strain gauges were attached on the model at the buccal and lingual positions of each implant. Forces simulating opposing natural dentition, conventional complete denture, and the parafunctional habit were applied to the models. The peri-implant strain in each strain gauge was recorded. Results: Least peri-implant strains (67 microstrains) were observed when forces simulating conventional complete dentures were applied on the models and the highest peri-implant strains (9091 microstrains) were observed when forces simulating parafunctional habit were applied. One-way ANOVA test followed by Tukey's post hoc analysis was performed to compare the mean deformation scores between different materials at 50 N load. The level of significance [P-value] was set at P < 0.05. Tests showed significant differences between zero mm and the other types in all the different materials, and also between 1.5 x AP and 2.5 x AP for Zirconia and Peek material at P = 0.02 & P = .008, respectively. The results showed that the type of framework material, cantilever length, and occlusal forces from the opposing arch influence the peri-implant strain in the bone in all-on-four implant-supported prostheses. Conclusion: Rehabilitation of a single, completely edentulous arch with implant-supported prostheses should consider the situation of the opposing arch. The choice of framework material, as well as the cantilever length, should be altered based on the forces from the opposing arch.

Introduction: Several techniques and methods have been proposed to estimate the anterior teeth dimensions in edentulous patients. However, this procedure remains challenging especially when preextraction records are not available. Therefore, the purpose of this study is to evaluate some of the existing extraoral and intraoral methods for estimation of anterior tooth dimensions and to propose a novel method for estimation of central incisor width (CIW) and length (CIL) for Saudi population. Materials and methods:Extraoral and intraoral measurements were recorded for a total of 236 subjects. Descriptive statistical analysis and Pearson's correlation tests were performed. Association was evaluated between combined anterior teeth width (CATW) and interalar width (IAW), intercommisural width (ICoW) and interhamular notch distance (IHND) plus 10 mm. Evaluation of the linear relationship between central incisor length (CIL) with facial height (FH) and CIW with bizygomatic width (BZW) was also performed.Results: Significant correlation was found between the CATW and ICoW and IAW (p-values <0.0001); however, no correlation was found relative to IHND plus 10 mm (p-value = 0.456). Clinical significance: Based on the results of the study, ICoW and IAW measurements can be useful in estimating the initial reference value for CATW, while the proposed novel approach using specific palatal dimensions can be used for estimating the width and length of central incisors. These methods are crucial to obtain esthetic treatment results within the parameters of the given population. Evaluation of the Current Techniques and Introduction of a Novel Approach for Estimating Maxillary Anterior

Background Coronavirus disease-19 (COVID-19) is a recent pandemic that is advancing at a rapid rate. The future course of the disease includes severe respiratory infection and also leads to death if unattended. Meticulous measures are necessary before attending any patient. The dental operatories and the clinic surroundings must be well sanitized so as to prevent the spread of pandemic. Aim and objective This review discusses in brief about the pathophysiology and course of COVID-19. Further, we discussed in detail the management aspects of patients in periodontal perspective and the sanitization procedures required for the dental clinic. Review results The SARS coronavirus enters the human circulation via the angiotensin-converting enzyme (ACE) receptors which are also found on the oral mucosal surfaces. Furin and Cathepsin L are the pro-inflammatory molecules released during pathogenesis of periodontitis and mediate the molecular pathways that help the virus invade into the host. The clinic set-up should be modified to best suit the pandemic conditions. This includes the three phases, i.e., phase I: preparatory phase; phase II: implementation phase; and phase III: follow-up. The patient management is explained based on the emergency needs of the patient based on the recent AAP classification of periodontal diseases and conditions 2017 as emergency, urgent, and elective treatment needs which have been explained in detail. Conclusion It can be strongly concluded that there is direct relationship between oral health and systemic health. The treatment procedures and sanitization protocols must be definitely modified. Further consensus and systematic reviews help us arriving at a more standardized protocol. Clinical significance This review would help clinicians modify the way they treat patients in the clinic and provide better services depending upon the emergency needs of the patient. How to cite this article Jafer MA, Hazazi MA, Mashi MH, et al. COVID-19 and Periodontitis: A Reality to Live with. J Contemp Dent Pract 2020;21(12):1398–1403.