SciCombinator

Discover the most talked about and latest scientific content & concepts.

Journal: Dentistry journal

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The human body supports the growth of a wide array of microbial communities in various niches such as the oral cavity, gastro-intestinal and urogenital tracts, and on the surface of the skin. These host associated microbial communities include yet-un-cultivable bacteria and are influenced by various factors. Together, these communities of bacteria are referred to as the human microbiome. Human oral microbiome consists of both symbionts and pathobionts. Deviation from symbiosis among the bacterial community leads to “dysbiosis”, a state of community disturbance. Dysbiosis occurs due to many confounding factors that predispose a shift in the composition and relative abundance of microbial communities. Dysbiotic communities have been a major cause for many microbiome related systemic infections. Such dysbiosis is directed by certain important pathogens called the “keystone pathogens”, which can modulate community microbiome variations. One such persistent infection is oral infection, mainly periodontitis, where a wide array of causal organisms have been implied to systemic infections such as cardio vascular disease, diabetes mellitus, rheumatoid arthritis, and Alzheimer’s disease. The keystone pathogens co-occur with many yet-cultivable bacteria and their interactions lead to dysbiosis. This has been the focus of recent research. While immune evasion is one of the major modes that leads to dysbiosis, new processes and new virulence factors of bacteria have been shown to be involved in this important process that determines a disease or health state. This review focuses on such dysbiotic communities, their interactions, and their virulence factors that predispose the host to other systemic implications.

Concepts: Immune system, Inflammation, Archaea, Disease, Infectious disease, Bacteria, Microbiology, Infection

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Evaluation of the effect of a high frequency acceleration device (HFA) on clear aligner exchange intervals and treatment time required to achieve prescribed tooth movements. Sixteen subjects with similar Class I malocclusions, ≤5 mm crowding, and treated with aligner orthodontic therapy (Invisalign) were divided into two groups. Group 1 (experimental; n = 8) underwent aligner treatment in conjunction with daily use of the HFA device and exchanged aligners every five days. Group 2 (controls; n = 8) underwent aligner treatment without use of the device and exchanged aligners every 14 days according to the manufacturer’s recommended interval. All subjects were treated by one investigator, and results-total number of aligners used, and number of refinements required-were evaluated by both prior to final mobile retention (Vivera) scan. A significant decrease in both treatment time and number of aligners required to complete treatment was observed by HFA subjects vs. controls. In addition, no refinements were required by HFA subjects, whereas six of eight control subjects required one or more refinements. The results of the present preliminary report showed that the use of the HFA device in conjunction with aligner orthodontic treatment resulted in a significant decrease in the length of treatment. Moreover, the number of patients requiring refining treatment was significantly lower.

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The purpose of this study was to investigate the effectiveness of a resorbable alloplastic in situ hardening bone grafting material for alveolar ridge preservation in a swine model. Seven Landrace pigs were used. In each animal, the maxillary left and right deciduous second molars were extracted, and extraction sites were either grafted with a resorbable alloplastic in situ hardening bone substitute, composed of beta-tricalcium phosphate (β-TCP) granules coated with poly(lactic-co-glycolic) acid (PLGA), or left unfilled to heal spontaneously. Animals were euthanized after 12 weeks, and the bone tissue was analyzed histologically and histomorphometrically. Linear changes of ridge width were also clinically measured and analyzed. Pronounced bone regeneration was found in both experimental and control sites, with no statistically significant differences. At the experimental sites, most of the alloplastic grafting material was resorbed and remnants of the graft particles were severely decreased in size. Moreover, experimental sites showed, in a statistically nonsignificant way, less mean horizontal dimensional reduction of the alveolar ridge (7.69%) compared to the control sites (8.86%). In conclusion, the β-TCP/PLGA biomaterial performed well as a biocompatible resorbable in situ hardening bone substitute when placed in intact extraction sockets in this animal model.

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With the increasing numbers of the elderly requiring care in Japan, the management of their oral health care will require cooperation between medical and dental professionals, and we need to transfer dental knowledge from dental professionals to caregivers. With the help of a questionnaire, we examined 181 caregivers' depth of understanding regarding 20 typical dental terms with a view to improving the educational instruction provided to them. It was found that except for “clasp”, popular dental terms have largely been accepted. The differences in their degrees of understanding could be owing to the lack of systematic education for caregivers.

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Light activated disinfection (LAD) is a strategy for optimizing root canal disinfection by using a highly-selective, targeted killing of bacteria using a combination of photosensitizers and light. Over the past decade, numerous in vitro and clinical studies have been performed to demonstrate the effectiveness of this mode of root canal disinfection. While most studies offer an important understanding of the effectiveness of LAD on monospecies biofilms, few have offered credence to the fact that infections of the root canal system are mediated by polymicrobial biofilms. Hence, it is imperative to understand the effect of LAD on polymicrobial biofilms both in terms of microbial killing and the changes in the biofilm architecture. The aim of this review was to systematically review the literature to evaluate the effect of LAD on dual and multispecies biofilms and demonstrate the antibiofilm effect of LAD. Two databases (PubMed and Scopus) were searched to identify eligible studies using a combination of key words. These studies were reviewed to draw conclusions on the effect of LAD on dual and multi species biofilm and the antibiofilm effect of LAD. It was found that LAD alone may be unable to eradicate dual and multispecies biofilms, but it may enhance the effect of conventional canal debridement strategies. Novel formulations of photosensitizers with nanoparticles showed the potential to inhibit biofilm formation and/or disrupt the biofilm architecture.

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Background—The literature related to minimally invasive periodontal surgery is reviewed. This includes the original minimally invasive surgery (MIS) procedure for bone regeneration, the modification of MIS for the minimally invasive surgery technique (MIST) and modified MIST (M-MIST) procedures, and the introduction of the videoscope for oral surgical procedures and the ability to perform videoscope-assisted minimally invasive surgery (VMIS). The evolution from MIS through MIST to the current VMIS is reviewed. The results from studies of each of these methods are reported. Conclusion—The use of small incisions that produce minimal trauma and preserve most of the blood supply to the periodontal and peri-implant tissues results in improved regenerative outcomes, minimal to absent negative esthetic outcomes, and little or no patient discomfort. Minimally invasive procedures are a reliable method to regenerate periodontal tissues.

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One of the potential complications of surgery for velopharyngeal insufficiency (VPI) is postoperative oral-nasal fistula (ONF). Reported rates vary from 0 to 60%. Several factors are on account of these disproportionate rates.

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The aim of the present study is to review the licensing process and challenges faced by foreign-trained dentists in United States (U.S.), and how incorporating foreign-trained dentists in the dental workforce in the U.S. impacts the population’s dental care. Foreign-trained dentists must complete additional training in a Commission of Dental Accreditation recognized program offered by a U.S. dental school in order to be eligible for licensing. Foreign-trained dentists interested in seeking employment in the U.S. face numerous challenges, including stringent admission processes, high tuition costs, immigration barriers and cultural differences. Opening the U.S. dental profession to foreign-trained dentists provides several advantages, such as increasing the diversity of dentists in the U.S., expanding access to underrepresented communities, and enhancing the expertise of the profession. Foreign-trained dentists are an important resource for a U.S. government seeking to build the human capital base and make the most of global trade opportunities through a “brain gain”. Increasing the diversity in the dental profession to match the general U.S. population might improve access to dental care for minorities and poor Americans, reducing disparities in dental care.

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Maxillectomy often results in a high level of morbidity with significant psychological and functional implications for patients. The aims of the present study were to assess the effectiveness of the maxillary obturator as a speech rehabilitation aid, to examine the influence of dentition on speech intelligibility, to restore patients’ regular daily activity as soon as possible, and to maintain patients’ psychological well-being throughout the treatment.

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The development of cognitive knowledge, motor skills, and artistic sense in order to restore lost tooth structure is fundamental for dental professionals. The course of dental anatomy is taught in the initial years of dental school, and is a component of the basic core sciences program in the faculties of dentistry. The learning objectives of the dental anatomy course include identifying anatomical and morphological characteristics of human primary and permanent teeth; identifying and reproducing tooth surface details in order to recognize and diagnose anatomical changes; and developing student’s psychomotor skills for restoring teeth with proper form and function. The majority of dental schools rely on traditional methods to teach dental anatomy, using lectures to convey the theoretical component; whereas the practical component uses two-dimensional drawing of teeth, identification of anatomical features in samples of preserved teeth, and carving of teeth. The aim of the present literature review is to summarize different educational strategies proposed or implemented to challenge the traditional approaches of teaching dental anatomy, specifically the flipped classroom educational model. The goal is to promote this approach as a promising strategy to teaching dental anatomy, in order to foster active learning, critical thinking, and engagement among dental students.