Since the digital impression technique has already been widely used in dental therapy, it has grown into a popular option among implant practitioners. The advantages of the digital impression technique are as follows: better experience for patients during the treatment; less chair-side time consumption; and reliability in making the precise impression. Thus, we reviewed the relevant factors that impact the precision of the digital impression technique and introduced its influence mechanism through an evidence-based method that was based on analyzing in vitro and in vivo literature published within the previous 5 years, with a focus on such considerations as relevant factors to dentists, digital impression systems, patients, and the environment. A review of the literature showed that the main factors that have a large influence on impression precision are imaging techniques and the software for the impression system. However, due to the development of impression systems that are restricted at scientific and technological levels, impression precision is affected by multiple factors, such as scanning techniques, dentist operation proficiency, material and contours of scanbodies, patient conditions, and ambient light. Dentists are advised to scientifically choose the impression system, limit ambient light and adopt direct techniques that could enhance impression precision. In the future, the development of impression systems could reduce the systematic errors, decrease the operating complexity of dentists, and improve impression precision.

Occlusal disorder is an abnormal condition in which the static and dynamic relations between the upper and lower teeth are not well aligned. The most common occlusal disorder in clinical practice is the inability to reach the intercuspal position due to early contact of individual points or occlusal interference due to occlusal high points, which can lead to periodontal tissue damage, decreased masticatory function, temporomandibular joint and muscle discomfort; these results can occur through the overactivation of the locus coeruleus-sympathetic-adrenal medullary system and hypothalamic-pituitary-adrenal axis induce elevated serum corticosteroid levels, which leads to chronic stress in the body. This article reviews the effects of chronic stress caused by occlusal disorder on bone tissue, stomatognathic system, emotional health and cognitive function. It has been found that occlusal disorders not only result in the loss of bone in the oral cavity, the reduction of bone mass in the whole body and damage to the local function of the stomatognathic system but also negatively affect the body’s anxiety, sleep, cognitive function and spatial memory ability as a result of the neuroendocrine changes. In recent years, concern about occlusal disorders has been on the rise. Early detection and timely adjustment of uncoordinated occlusion has become an issue that cannot be ignored in the clinic.