Background Among several potential transmission sources in the spreading of the COVID-19, dental services have received a high volume of attention. Several reports, papers, guidelines, and suggestions have been released on how this infection could be transmitted through dental services and what should be done. This study aimed to review the guidelines in order to develop a practical feasibility protocol for the re-opening of dental clinics and the reorientation of dental services. Methods This study systematically reviewed the published literature and the guidelines of international health care institutions on dentistry and COVID-19. We searched Pubmed, Web of Science, and SCOPUS electronic databases using MESH terms. The recommendations identified were tested with a convenience sample of experienced practitioners, and a practical step-by-step protocol is presented in this paper. Results To the date this paper was drafted, 38 articles were found, of which 9 satisfied our inclusion criteria. As all the nine studies were proposed in a general consensus, any elective non-emergency dental care for patients with suspected or known COVID-19 should be postponed for at least 2 weeks during the COVID-19 pandemic. Only urgent treatment of dental diseases can be performed during the COVID-19 outbreak taking into consideration pharmacological management as the first line and contagion-reduced minimally invasive emergency treatment as the secondary and final management. Conclusions While the currently available evidence has not demonstrated a clear and direct relationship between dental treatment or surgery and the possibility of the transmission of COVID-19, there is clearly the potential for transmission. Therefore, following the protective protocols in the COVID-19 crisis is of utmost importance in a dental setting.

Introduction: Dentinal hypersensitivity (DH) is an acute intensive tooth pain which can lead to dental annoyances during eating and drinking. Stimulating exposed dentinal tubules by either kind of thermal, tactile, chemical and/or osmotic stimuli is believed to be the cause of this pain. It is hypothesized that dentinal tubules’ orifice occlusion (DOO) can help relieve such dental irritations. Thus, this systematic review was conducted to evaluate the effectiveness of laser application as a prevention and treatment modality on DH reduction. Methods: Electronic databases (MEDLINE, SCOPUS) were searched among randomized clinical trials from January 2007 to December 2016. The extraction of data and quality assessments were carried out by different independent observers. Results: A total of 499 items were found of which3 9 relevant articles were extracted. The profound findings proved lasers’ effectiveness as a treatment of DH. Although some of the researches reported no significant difference between laser and other desensitizing agents, most of the studies suggested that better results (both rapid and long-lasting) were obtained in combined modalities. Furthermore, the preventive role of this new technology has been emphasized as well. Nd-YAG (neodymium-doped yttrium aluminum garnet) and diode lasers reduce DH after bleaching. Lasers can also protect cervical restorations from DH due to tubular occlusion. Moreover, it is suggested to apply lasers in relief of DH following scaling and root planning. Nevertheless, a few researchers dispute its beneficence as a result of placebo effect. Conclusion: The results obtained from several studies in the present review revealed that the application of lasers is effective not only in terms of treatment of DH, but also in the prevention of this intensive tooth pain. Among various types of lasers, the application of Nd:YAG laser has shown the best results in DH treatment.

No abstract

SUMMARY Background: This study investigated the hardness and color stability of five resin composites subjected to different polishing methods following immersion in distilled water or lactic acid for up to three months. Methods and Materials: Three nanohybrid, Paradigm (3M ESPE), Estelite Sigma Quick (Tokuyama), Ice (SDI), and two microhybrid, Filtek P60 and Filtek Z250, composites were examined. Disc-shaped specimens (10×1.5 mm) were prepared and immersed in distilled water for 24 hours then polished using either silicon carbide paper, the Shofu polishing system or were left unpolished (control). The CIE values and microhardness were determined using a spectrophotometer and digital Vickers hardness tester, respectively (n=10) after one, 45, and 90 days of storage in distilled water or lactic acid. Data were analyzed using analysis of variance, Tukey test, and Pearson correlation coefficient. Results: Ice exhibited the greatest color change, yet Paradigm and Filtek P60 demonstrated the least. Overall, discoloration of tested materials was multifactorial and the effect of storage media depended on the material, polishing method and time interval. The greatest hardness was obtained for Paradigm and the lowest for Estelite. Hardness was found to be significantly higher in lactic acid after 45 days (p=0.014) and even higher after 90 days (p<0.001) compared with distilled water. Conclusions: An acidic environment did not adversely affect color stability or microhardness of the resin composites. There was a significantly mild reverse correlation between hardness and color change in both storage media.

Since the emergence of the new coronavirus disease (COVID-19), profound alterations in general and specialist dental practice have been imposed to provide safe dental care. The guidelines introduced in response to the COVID-19 pandemic to mitigate healthcare disruption are inconsistent regarding the dental practice re-installation, particularly during a transitional time. Despite the successful mass vaccination campaigns rolled out in 2021, the presence of more than 80 genotypes of COVID-19, rapid neutralisation of antibodies within a short period of seropositivity, and the likelihood of recurrent infection raise some doubts on whether vaccination alone will provide long-term immunity against COVID-19 and its variants. Here, from this perspective, we aim to provide an initial proposal for dental services reinstallation, easily applicable in various care settings. We discuss the potential options for the transition of dental services, as well as challenges and opportunities to adapt to new circumstances after mass COVID-19 vaccination. The proposal of the universal three-tier system of dental services resumption, determined by regional COVID-19 rates, testing accessibility, and vaccination rollout has been presented. Following herd COVID-19 immunity enhancement, it would be prudent to confer various preventative measures until virus spread naturally diminishes or becomes less virulent. Based on modelling data, dental practices may not return to normal, routine operation even after global vaccination as there would still be a significant risk of outbreaks of infection. Variable, multi-level measures will still be required, depending on the local COVID-19 cases rate, to secure safe dental care provision, despite predicted success of vaccination agendas. This approach can be implemented by achievable, practical means as a part of risk assessment, altered work pattern, and re-arrange of dental surgery facilities. The adequate standard operating procedure, with the support of rapid point-of-care testing at workplace, would vastly intensify the uninterrupted recovery of the dental care sector.

Abstract Among several potential sources of transmission for the spreading of the COVID-19, dental services have received a high volume of attention. Several reports, papers, guidelines, and suggestions have been released on how this infection could be transmitted through dental services, and what should be done. This study has systematically reviewed the published literature on dentistry and COVID-19 in order to develop a practically feasible protocol for re-opening and reorientation of dental services. The recommendations identified were tested with a convenience sample of experienced practitioners, and a practical step-by-step protocol is presented in this paper.

The present study aimed to investigate the efficiency of passive ultrasonic irrigation (PUI), EndoActivator (EA), standard needle irrigation (SNI), and XP-endo Finisher files in removing pure calcium hydroxide (pCH) and injectable CH from in vitro root resorption cavities. Using a rotary system, the root canals of 116 extracted single rooted teeth were prepared. Imitated internal resorption cavities were then created in root halves. The specimens were divided into two groups according to the form of CH (n = 58): (I) pCH; (II) injectable CH. The teeth of each group were randomly divided into six subgroups: negative control (n = 5), positive control (n = 5), PUI (n = 12), XP-endo Finisher (n = 12), EA (n = 12), and SNI (n = 12). The root canals were irrigated using NaOCl and EDTA and split longitudinally, and both halves were evaluated with a stereomicroscope. Kruskal–Wallis and Mann–Whitney U tests were used to analyze data. The present results revealed that PUI completely removed pCH in 79% and injectable CH in 70.8% of the internal resorption cavities which was significantly higher than other methods (p<0.05). There was no statically significant difference between different forms of CH in terms of CH removal (p=0.918). The PUI technique was observed as the most efficient method of P-CH and injectable CH removal from a replicated internal resorption cavity. Finally, according to the findings, different forms of CH were comparable in terms of CH removal.

Adhesion between the resin-based materials and the tooth substrate is the foundation of restorative dentistry. Despite all the improvements in adhesive systems, the hybrid layer, which is the interface of the bonding between the tooth substrate and adhesive materials, remains the weakest area in adhesive dentistry. [1] In general, it is accepted that the resin-dentin bond created by adhesives deteriorates over time. Degradation of the hybrid layer is the main cause of this phenomenon. Decreased resin monomer diffusion within the acid-etched creates incompletely infiltrated zones along the bottom of the hybrid layer that contains denuded collagen fibrils. These denuded collagen fibrils are vulnerable to degradation by endogenous matrix metalloproteinases (MMPs). [2] MMPs are a group of calcium-and zinc-dependent host-derived enzymes that are trapped within the mineralized dentin matrix during tooth development. They can hydrolyze components of the extracellular matrix.Dentinogenesis is a complicated developmental phenomenon that requires the active extra-cellular enzymatic function of several different proteinases, mainly of the MMP family. Recent studies revealed the contributions of host-derived proteinases to the breakdown of the collagen matrices in the pathogenesis of dentin and periodontal disease. [3] The existence of an acidic environment due to caries leads to the activation of different MMPs and degradation of the collagen fibrils, hence weakening the bond between the adhesive and dentin interface occurs. [4] During bonding procedures with etch-and-rinse or self-etch systems, demineralization of dentin activates proteolytic enzymes (MMPs), which degrades unprotected