Gene Delivery Therapeutics in the Treatment of Periodontitis and Peri-Implantitis : A State of the Art Review

Background: Periodontal disease is a chronic inflammatory condition that affects supporting tissues around teeth, resulting in periodontal tissue breakdown. If left untreated, periodontal disease could have serious consequences; this condition is in fact considered as the primary cause of tooth loss. Being highly prevalent among adults, periodontal disease treatment is receiving increased attention from researchers and clinicians. When this condition occurs around dental implants, the disease is termed peri-implantitis. Periodontal regeneration aims at restoring the destroyed attachment apparatus, in order to improve tooth stability and thus reduce disease progression and subsequent periodontal tissue breakdown. Although many biomaterials have been developed to promote periodontal regeneration, they still have their own set of disadvantages. As a result, regenerative medicine has been employed in the periodontal field, not only to overcome the drawbacks of the conventional biomaterials but also to ensure more predictable regenerative outcomes with minimal complications. Regenerative medicine is considered a part of the research field called tissue engineering/regenerative medicine (TE/RM), a translational field combining cell therapy, biomaterial, biomedical engineering and genetics all with the aim to replace and restore tissues or organs to their normal function using in vitro models for in vivo regeneration. In a tissue, cells are responding to different micro-environmental cues and signaling molecules, these biological factors influence cell differentiation, migration and cell responses. A central part of TE/RM therapy is introducing drugs, genetic materials or proteins to induce specific cellular responses in the cells at the site of tissue repair in order to enhance and improve tissue regeneration. In this review, we present the state of art of gene therapy in the applications of periodontal tissue and peri-implant regeneration. Purpose: We aim herein to review the currently available methods for gene therapy, which include the utilization of viral/non-viral vectors and how they might serve as therapeutic potentials in regenerative medicine for periodontal and peri-implant tissues

Pre-augmentation soft tissue expansion: An overview

Objectives: The aim of this study was to explore the development of soft tissue expanders, their different types and their potential applications prior to bone augmentation and implant placement. Material and Methods: A review of pertinent literature was performed using PubMed to comprehend the dynamics of soft tissue expanders and determine the current position of their pre-augmentation applications. Results: There is promising, albeit preliminary information regarding the benefits of pre-augmentation soft tissue expansion. Findings cannot be generalised due to relatively small sample size. Conclusions: Further clinical trials with larger sample sizes and long-term follow-up are needed before soft tissue expanders can be confidently applied in everyday clinical practice

Periodontal health awareness among gynecologists in Riyadh, Saudi Arabia

Abstract OBJECTIVE: To determine the knowledge of periodontal disease and pregnancy outcomes among the gynecologists practicing in Riyadh, Saudi Arabia. MATERIALS AND METHODS: A cross-sectional survey of 200 randomly chosen gynecologists from Riyadh was carried out by using a structured, self-administered, closed-ended questionnaire. Knowledge of periodontal disease and possible ways of prevention; knowledge of periodontal disease and pregnancy outcomes; and oral self-care attitudes among gynecologists were assessed. RESULTS: One-quarter of the gynecologists knew the meaning of dental plaque. Almost 57.5% believed that the frequency of toothbrushing should be increased during pregnancy. Eighty percent of gynecologists were aware of the serious effects of smoking on the pregnant woman and her child. Less than half (44.5%) believed that there is a relationship between gum disease and premature labor. Gynecologists working in the government sector were significantly more aware about the causes of inflamed gum in pregnancy, gum disease and its prevention, and negative effects of smoking on pregnancy. A significantly higher percentage of male and senior gynecologists aged between 50 and 54 years answered that gum disease would lead to the delivery of a preterm or low-birth-weight infant. CONCLUSION: Gynecologists considered in the present study showed an acceptable level of knowledge and awareness toward periodontal health and the association between periodontal disease and adverse pregnancy outcomes

Free energy density for mean field perturbation of states of a one-dimensional spin chain

Motivated by recent developments on large deviations in states of the spin chain, we reconsider the work of Petz, Raggio and Verbeure in 1989 on the variational expression of free energy density in the presence of a mean field type perturbation. We extend their results from the product state case to the Gibbs state case in the setting of translation-invariant interactions of finite range. In the special case of a locally faithful quantum Markov state, we clarify the relation between two different kinds of free energy densities (or pressure functions).Comment: 29 pages, Section 5 added, to appear in Rev. Math. Phy

Correlation between sequence hydrophobicity and surface-exposure pattern of database proteins

Hydrophobicity is thought to be one of the primary forces driving the folding of proteins. On average, hydrophobic residues occur preferentially in the core, whereas polar residues tends to occur at the surface of a folded protein. By analyzing the known protein structures, we quantify the degree to which the hydrophobicity sequence of a protein correlates with its pattern of surface exposure. We have assessed the statistical significance of this correlation for several hydrophobicity scales in the literature, and find that the computed correlations are significant but far from optimal. We show that this less than optimal correlation arises primarily from the large degree of mutations that naturally occurring proteins can tolerate. Lesser effects are due in part to forces other than hydrophobicity and we quantify this by analyzing the surface exposure distributions of all amino acids. Lastly we show that our database findings are consistent with those found from an off-lattice hydrophobic-polar model of protein folding.Comment: 16 pages, 2 tables, 8 figure