Fournierjarvis0348

This paper introduces these recent developments in CAD/CAM of RPD.Objective To investigate the effectiveness of a digital virtual simulation training system applied in the preclinical teaching of access and coronal cavity preparation. Methods Twenty dental undergraduate students from Peking University School and Hospital of Stomatology were recruited and divided randomly and equally into two groups according to the random number method after being unified with theory training, including access and coronal cavity preparation skills assessment form and Simodont system operation manual. Tests for access and coronal cavity preparation skills by using standard simulation plastic teeth were performed and the scores were recorded as baseline for each student. Students in group of virtual simulation priority were trained using Simodont virtual simulation system, while those in group of phantom-simulator priority were trained using conventional phantom-simulator system. Access and coronal cavity preparation skills of standard simulation plastic teeth were assessed once again and recl simulation system has the characteristics of repeatability, multi-dimension and multiple practice, and provides me with more attention to details" [80% (16/20)], however "it needs to be improved and upgraded to be close to the conventiaonl phantom-simulator system" [90% (18/20)]. Conclusions Compared with using the conventional phantom-simulator system only, the preclinical teaching effectiveness of access and coronal cavity preparation could be effectively improved by using Simodont virtual simulation system combined with the phantom-simulator training system and might influenced by the training sequence.Objective To provide a scientific basis for the standardized operation of clinical disinfection by comparing and analyzing the influence of disinfection times on the accuracy of digital intraoral scanning. Methods The author prepared 10 brand-new intraoral scanning heads (Trios, 3Shape, Denmark), scan the same plaster standard dentition model after 1, 20, 40, and 60 times of pressure steam sterilization, and obtained the data of four groups of experimental groups A, B, C, D, and scan the model 5 times repeatedly after each disinfection cycle of each scanning head. A model scanner (D2000, 3Shape, Denmark) was used to scan the standard dentition model, and the scan results were used as the control group data. Vernier calipers and measurement software were used to measure the arch length (the distance between the mesial cheek tips of the first molars on both sides of the maxillary) and the front and back length (the distance from the tongue protrusion of the right incisor to the buccal tip of the first molar on lly acceptable range. After 60 times of pressure steam sterilization, the accuracy of digital scan data can still meet clinical needs.Objective To investigate the relationship between age, sex, length of upper lip and the exposure of maxillary central incisor. Methods A total of 304 participants in normal occlusion (154 males, 150 females, aged 18-49 years) were recruited in this study from patients, visited the Medical Examination Center, Affiliated People's Hospital, Shanxi Medical University from January 2019 to August 2020. Participants were divided into 18-29 years old group (104, 53 males, 51 females), 30-39 years old group (110, 56 males, 54 females) and 40-49 years old group (90, 45 males, 45 females). Facial photography was used to record the facial state during the mandibular postural position, "che" pronunciation position and posed smile. The upper lip length, upper lip thickness and the exposure of maxillary central incisor were measured by ImageJ. The differences of measurement items in each group and the gender differences of each measurement item were analyzed. The length of upper lip and the exposure of upper central incisor in the mandibular postural position were analyzed by Pearson correlation. see more Results In the mandibular postural position, the length of upper lip was (21.9±2.2), (22.5±2.5) and (23.1±2.2) mm in the 18-29 years old, 30-39 years old and 40-49 years old groups, and the length of upper lip in the 40-49 years old group was significantly larger than that in the 18-29 years old group (P0.05). There was a significant linear correlation between the exposure of upper central incisor and the length of upper lip at the mandibular postural position in normal occlusion aged 18-49 (r=-0.325, P less then 0.01). Conclusions Gender factor should be considered in the esthetic design of anterior teeth. The exposure of anterior teeth in the mandibular postural position and "che" pronunciation position is more valuable than that in the posed smile. The length of upper lip in normal occlusion aged 40-49 was significantly shorter than that aged 18-29, and the exposure of upper central incisors was significantly reduced.Burning mouth syndrome (BMS) is one of the most common mucosal diseases. Although a variety of therapies have been reported to treat BMS, there is a lack of widely recognized therapies and it is still a dilemma for clinicians to treat BMS. Led by the Chinese Stomatological Association, the first edition of evidence-based guideline for clinical practice of BMS was developed under the guidance of WHO Handbook for Guideline Development. The 27 recommendations were formed from the following 6 aspects pre-treatment examination, removal of stimuli, medication, physical therapy, psychological therapy and antipsychotics. There are 3 strong recommendations and 12 weak recommendations in pre-treatment examination and removal of stimuli, as well as 12 weak recommendations in therapies, which could provide the references for clinical practice of BMS in China.Objective To evaluate the preliminary clinical effect of flap-raising and cortical-perforation based extraction method in patients with potential risk of medication-related osteonecrosis of the jaw (MRONJ). Methods Eighteen patients, who needed teeth extraction in the Department of Oral and Maxillofacial Surgery, Peking University School and Hospital of Stomatology from February 2016 to November 2020, with a history of using anti-resorption/anti-angiogenesis medication were included in this retrospective study. According to the characteristics of the patient's medication history, patients were stratified into three categories, low-dose anti-resorption drug group, high-dose anti-resorption drug group, and high-dose anti-resorption combined with anti-angiogenesis targeted drug group. There were 15 females and 3 males, the average age was 62.4 years (range from 27 to 87 years) old. A total of 31 teeth were indicated for extraction due to chronic infection. The flap-raising and cortical-perforation techniques were used to extract the affected teeth, and the patients were followed up closely.