Dental caries in primary and permanent teeth in children's worldwide, 1995 to 2019: a systematic review and meta-analysis

Background: Early childhood caries (ECC) is a type of dental caries in the teeth of infants and children that is represented as one of the most prevalent dental problems in this period. Various studies have reported different types of prevalence of dental caries in primary and permanent teeth in children worldwide. However, there has been no comprehensive study to summarize the results of these studies in general, so this study aimed to determine the prevalence of dental caries in primary and permanent teeth in children in different continents of the world during a systematic review and meta-analysis. Methods: In this review study, articles were extracted by searching in the national and international databases of SID, MagIran, IranMedex, IranDoc, Cochrane, Embase, ScienceDirect, Scopus, PubMed, and Web of Science (ISI) between 1995 and December 2019. Random effects model was used for analysis and heterogeneity of studies was evaluated by using the I2 index. Data were analyzed by using the Comprehensive Meta-Analysis (Version 2) software. Findings: In this study, a total of 164 articles (81 articles on the prevalence of dental caries in primary teeth and 83 articles on the prevalence of dental caries in permanent teeth) were entered the meta-analysis. The prevalence of dental caries in primary teeth in children in the world with a sample size of 80,405 was 46.2% (95% CI: 41.6–50.8%), and the prevalence of dental caries in permanent teeth in children in the world with a sample size of 1,454,871 was 53.8% (95% CI: 50–57.5%). Regarding the heterogeneity on the basis of meta-regression analysis, there was a significant difference in the prevalence of dental caries in primary and permanent teeth in children in different continents of the world. With increasing the sample size and the year of study, dental caries in primary teeth increased and in permanent teeth decreased. Conclusion: The results of this study showed that the prevalence of primary and permanent dental caries in children in the world was found to be high. Therefore, appropriate strategies should be implemented to improve the aforementioned situation and to troubleshoot and monitor at all levels by providing feedback to hospitals

Mitigating the foreign body response through ‘immune-instructive’ biomaterials

ObjectivesBiomaterials are routinely used in clinical applications. A key to the clinical success of implanted biomaterials is not eliciting detrimental immune responses. In this article, we provide an overview of immune responses to biomaterials, along with biomaterial-based approaches to mitigate the adverse host reactions while supporting pro-healing immune responses. We also review existing in-vitro models used to assess the biocompatibility of biomaterials.Key findingsOnce implanted, biomaterials are often detected as foreign bodies by the immune system, triggering detrimental immune responses. Such responses could damage host tissues and impair the function of implanted materials or devices. Therefore, there is substantial interest in developing new materials and tools with the ability to modulate immune responses to support tissue regeneration and healing processes. However, the bioengineering of immune responses through biomaterials requires detailed understanding of how the immune system typically responds to foreign materials. This knowledge can inform designing materials with bio-instructive chemistries and/or surface attributes. In this review, first we briefly discuss basic aspects of the foreign body response followed by different strategies for developing ‘immune-instructive’ biomaterials, models to test their efficacy and examples of their clinical applications.ConclusionsPromising progress has been made in the field of biomaterial engineering however, how different immune cells interact with biomaterials is yet to be fully elucidated. A better understanding of cell-material interactions, and particularly the impact of inter-individual variations, will allow the development of new generation of more personalised ‘immune-instructive’ biomaterials and medical devices to modulate immune responses towards anti-inflammatory and pro-healing phenotypes