ABSTRACT
Background: Covid-19 is a worldwide pandemic causing considerable morbidity and mortality. Many studies have shown the influence of periodontal health on systemic disease. Aims: This article explores the association between periodontal disease (PD), oral dysbiosis and cytokine storm requiring proto- col of maintainence of oral hygiene in covid patients and also in healthy individuals during the pandemic. Covid patients need to be motivated to maintain proper oral hygiene measures to avoid risk of Covid related adverse outcomes. Methods: Data was collected and analyzed from recently published literature and electronic database searches of PubMed and Google Scholar. Results: Covid-19 leads to increased release of cytokines from host cells termed as cytokine storm, many of the components of which are common with the cytokine expression profile of periodontitis. It has been shown that periodontitis was significantly associated with increased risk of complications from the Covid-19 including ICU admission, need for assisted ventilation and death. Conclusion: Plaque control is important to prevent exchange of microorganisms between the oral cavity and the lungs and to reduce the chances of worsening respiratory disease during Covid-19 infection. Understanding this association may definitely help to identify individuals at high risk and deliver appropriate care at early stages.
ABSTRACT
Statement Of Problem;Developments in ceramic core materials such as lithium disilicate, aluminium oxide, and zirconium oxide have allowed more widespread application of all-ceramic restorations over the past 10 years. However, establishing a reliable bond of resin cement to zirconia based materials has been proven to be difficult, which is the major limitation against fabricating zirconia restoration , and there is no clear recommendation in the literature regarding surface treatment before bonding. Purpose; This study evaluated the effect of zirconia surface treatments namely Airborne Particle Abrasion, Hydrofluoric acid etching, Hydrofluoric acid etching followed by silanation and Primer application on shear bond strength to a self etch dual cure resin cement bonded to dentin specimens. Material And Methods; Twenty zirconia rods (3 x 2.5 mm) were prepared from zirconia blocks and assigned into 5 groups. Each group were subjected to the following surface treatments. (1) group I - Control ( C ) no treatment , (2) group II - airborne-particle abrasion (APA), (3) group III – hydrofluoric acid etching ( HF ), (4) group IV - hydrofluoric acid etching followed by silanation ( HF/S ), and (5) group V - application of zirconia primer ( Z ) . Dentin specimens were prepared from extracted molars stored in 0.5% chloramine-T. Zirconia rods were bonded to dentin using a resin cement (Multilink Speed), then light polymerized. The specimens were loaded to failure with the notched shear bond test method in a universal loading apparatus. Results were analyzed using 1-way ANOVA (alpha=.05). Results;ANOVA showed significant differences in bond strength among the different surface treatments ( p value 0.001). The highest values were obtained with group V (Z) ( 8.66 Mpa) followed by group II (APA) (6.71 Mpa ), group IV (HF/S) (4.41 Mpa) . The least values were obtained for group III (HF) (3.88 Mpa ) and there were no significant difference ( p value 0.53 ) between group III (HF) ( 3.88 Mpa ) and group I (C) (3.70 Mpa).Conclusion:The resin bond to Y-TZP was improved by surface treatment. Zirconia Primer application is practically a reliable surface treatment . Airborne Particle Abrasion , although not so reliable , is also an effective treatment while bonding zirconia to a resin cement .