The clinical demand for occlusal reconstruction increases rapidly with increasing number of patients who have lost their normal occlusion because of tooth wear and dentition defects. Occlusal reconstruction is a special type of restoration defined as a comprehensive restoration of the function of the stomatognathic system by reestablishing a uniform and stable occlusal relationship between the upper and lower dentitions. Occlusal function analysis is an important part of occlusal reconstruction to achieve accurate restoration design and adjustment. Digital occlusal function analysis was conducted to monitor the movement of the mandible and obtain related data for the parameter design of occlusal reconstruction. Preoperative design, intraoperative adjustment, and postoperative verification were achieved, thereby improving the efficiency and accuracy of occlusal reconstruction.
Anterior diastema is a common esthetic defect in China. The general treatment for a patient with diastemata, including orthodontics and direct and indirect restorations, is a multidisciplinary clinical procedure covering the orthodontics, operative dentistry, general dentistry, and prosthodontics department. Given the diversity of departments and the complex etiology of this defect, decision-making regarding the closing methods and time selection is undefined and unintegrated, which makes the long-term stability of closure unpredictable. This article proposed an etiology-based decision tree with actual measurement of diastemata width for diastemata closure. The decisional steps include classifying the etiological factors based on patients' medical history and clinical manifestation to evaluate the stability of diastemata. After maintaining the stability of diastemata, contemporary and multidisciplinary treatment plans were selected in accordance with the measured width of diastemata and patients' cosmetic psychology, economics, and available time. These decision trees focus on the challenges of collaboration among dental departments, propose an objective and efficient ways for connections, and promote efficient and effective diastemata closure.
Dental invagination is an abnormality of the crown or root development induced during tooth germ development when the enamel-forming apparatus or epithelial root sheath overpopulates and folds into the papilla. In severe cases, the invaginated channels are connected to the pulp and periodontal tissues, often causing endodontic and periapical diseases. The complex anatomical pattern of this disease adds difficulty in its preoperative diagnosis and clinical operation. In this paper, we report a case of non-surgical treatment assisted by cone beam CT and microscopy for maxillary lateral incisor double dens invaginatus type Ⅲ (Ⅲa and Ⅲb) with apical periapical infection. After 1-year follow-up, the affected tooth was asymptomatic and the periapical lesion was significantly reduced.
Objectives: This study aims to analyze the clinical epidemiology, diagnostic and treatment characteristics of minor patients with maxillofacial fracture and provide a reference for the prevention and treatment.
Methods: The clinical data of minor patients with maxillofacial fracture in Departmentof Traumatic and Plastic Surgery, West China Hospital of Stomatology, Sichuan University, from January 1, 2015 to December 31, 2020 were retrospectively studied and statistically analyzed in terms of age, gender, etiology, anatomic sites and treatment modalities.
Results: The mean age of the patients was (10.65±5.15) years, and the male-to-female ratio was 1.91∶1. High fall was the primary cause of maxillofacial fractures in minors aged 0-6 years. Traffic accident injuries were the main cause of maxillofacial fractures in minors aged 7-12 and 13-17 years. About 65.13% of the midface and 83.08% non-condylar fractures were mainly treated by surgery, and condylar fractures were treated conservatively in 74.73% and by surgical treatment in 25.27%.
Conclusions: The etiology of maxillofacial fractures in minors differs at different ages, so prevention strategies should be adjusted according to age. Surgical treatment has become the preferred treatment modality for midface and non-condylar fractures. Conservative treatment is still the main treatment method for condylar fractures, but the proportion of surgical treatment increases.
Objectives: This study aimed to investigate the temporal and spatial changes in the expression of periostin during periodontal inflammation in mice.
Methods: A periodontitis model was constructed using silk thread ligation. Mice were randomly divided into five groups including control group, 4-day ligation group, 7-day ligation group, 14-day ligation group, and self-healing group (thread removal for 14 days after 14-day ligation). Micro-CT and histological staining were performed to characterize the dynamic changes in the mouse periodontal tissue in each group. RNAscope and immunohistochemical staining were used to analyze the pattern of changes in periostin at various stages of periodontitis. The cell experiment was divided into three groups: control group, lipopolysaccharide (LPS) stimulation group (treated with LPS for 12 h), and LPS stimulation removal group (treated with LPS for 3 h followed by incubation with medium for 9 h). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of periostin, transforming growth factor-β1 (TGF-β1), and matrix metalloproteinase 2 (MMP2).
Results: Significant alveolar bone resorption was observed 7 days after ligation. With increasing duration of ligation, the damage to the mouse periodontal tissue was aggravated, which manifested as increased osteoclasts, widening of the periodontal membrane space, and decreased alveolar bone height. Some degree of periodontal tissue repair was observed in the self-healing group. Periostin expression decreased at 4 and 7 days compared with the control group and increased at 14 days compared with 4 and 7 days. A significant recovery was found in the self-healing group. The qRT-PCR results showed that the expression of periostin and TGF-β1 in the LPS stimulation group decreased compared with that in the control group but significantly recovered in the LPS removal group.
Conclusions: Periostin expression in the PDL of mice showed a downward and upward trend with inflammation progression. The significant recovery of periostin expression after removing inflammatory stimuli may be related to TGF-β1, which is crucial to maintain the integrity of the PDL.
Most of the maxillary impacted third molars are located in the maxillary tuberosity, where the vision and operation space are limited. This paper reports a case of surgical extraction of the left maxillary horizontal superhigh impacted third molar, which is located between the roots of the adjacent teeth and is closely related to the maxillary sinus. The digital simulation technology was used to reconstruct a three-dimensional visual image of the patient's maxilla, related teeth, and other adjacent anatomical structures to assist in finding the optimal surgical method accurately. Root dislocation before the crown not only protects the roots of the adjacent tooth, but also reduces the risk of maxillary sinus lining damage or perforation during operative procedures, improves the efficiency of the operation, and reduces surgical trauma, which conforms to the concept of minimally invasive surgery and provides a new idea and experience for the clinical extraction of such maxillary impacted third molars.
Objectives: This study aims to investigate bond strength between zirconia and resin cement through surface treatments with Er: YAG laser, Nd: YAG laser, and Si-Zr coating.
Methods: Seventy-five round pre-sintered zirconia discs with a diameter of 18 mm and a thickness of 1.5 mm were prepared by a powder compactor. Fifty discs were randomly divided into five groups of 10 discs each and were subjected to five surface treatments: no treatment (control group), sandblasting with alumina particles (sandblasting group), Er: YAG laser treatment (Er: YAG laser group), Nd:YAG laser treatment (Nd: YAG laser group), and Si-Zr coating treatment (Si-Zr coating group). The discs were then bonded to composite resin columns with resin cement. The shear bond strength of each group was tested with a universal tester. Roughness tester, scanning electron microscope (SEM), and energy dispersive spectroscopy were used to analyze surface performance.
Results: The bond strength of the Si-Zr coating group was higher than that of the remaining groups (P<0.05). The difference in bond strength between the sandblasting group and the Er: YAG laser group was not statistically significant (P>0.05), but both of them had higher bond strength than the Nd: YAG laser group (P<0.05). The Si-Zr coating group had the highest surface roughness (P<0.05). The surface roughness of the sandblasting, Er: YAG laser, and Nd: YAG laser groups was higher than that of the control group (P<0.05), but the difference among the three groups was not statistically significant (P>0.05). SEM observations showed irregular scratches on the surface of the sandblasting group and large pits with holes on the surface of the Er: YAG and Nd: YAG laser groups. In the Er: YAG laser group, the crystal structure was replaced by a smooth surface with a large amount of microcracks due to partial melting. Complex porous structures that comprised "island-like" structures and mass pores among the grains were observed on the surface of the Si-Zr coating. Only Zr, O, and Y were detected on the surfaces of the control, Er: YAG laser, and Nd: YAG laser groups. Al was found on the surface of the sandblasted group, and a higher proportion of Si was detected on the surface of the Si-Zr coating group.
Conclusions: Er: YAG laser and Nd: YAG laser treatment on the zirconia ceramic surface could increase roughness and improve the bond strength to resin cement. Si-Zr coating treatment is an effective alternative for increasing the roughness and bond strength of zirconia surface and is superior to sandblasting and laser treatments.
Objectives: This study aimed to systematically compare the effects of flapless and flapped implantations on the surrounding soft tissues of dental implants.
Methods: Nine databases were searched, including PubMed, Embase, Cochrane Library, Web of Science, Clinical Trials, OpenGrey, OpenDoar, Scopus, and Ovid, from January 1, 2013, to August 27, 2023. Randomized controlled trials comparing flapless implantation with flapped implantation for restoration of missing teeth were included. Meta-analysis was conducted on studies that met the inclusion criteria by using RevMan 5.3 and Stata 14.0.
Results: A total of 1 245 articles were retrieved, and 17 studies were ultimately included. The results of Meta-analysis showed that flapless implantation resulted in better healing of the soft tissues around the dental implants than flapped implantation. Moreover, flapless implantation showed superior changes in implant success rate [mean difference (MD)=1.06, 95% confidence interval (CI) (1.02, 1.10), P=0.004], the width of keratinized gingival changes [MD=0.10, 95%CI (0.00, 0.20), P=0.04], and probing depth [MD=-0.60, 95%CI (-0.67, -0.53), P<0.000 01], with statistically significant differences. The final combined results of modified plaque index [standardized mean difference (SMD)=-0.41, 95%CI (-0.81, 0.00), P=0.05] and modified sulcus bleeding index [SMD=-0.44, 95%CI (-0.78, -0.10), P=0.01] showed superiority over flapped implantation. The papillary presence index was higher in the flapless implantation group than in the flapped implantation group. No statistically significant differences were observed in plaque index and gingival indices changes between the two groups.
Conclusions: Flapless implantation can achieve higher implant success rate, smaller changes in the width of keratinized gingival, and smaller probing depths than flapped implantation. It also has advantages in terms of modified plaque index, modified sulcus bleeding index, and papillary presence index.
Objectives: This study aims to investigate the influence of glucose regulated protein (GRP) 78 on osteoblast differentiation in periodontal ligament fibroblasts (PDLFs) under cyclic mechanical stretch and determine the underlying mechanism.
Methods: FlexCell 5000 cell mechanical device was applied to simulate the stress environment of orthodontic teeth. GRP78High and GRP78Low subpopulation were obtained by flow sorting. Gene transfection was performed to knockdown GRP78 and c-Src expression and overexpress c-Src. Western blot analysis was used to detect the protein expression of Runt-related gene 2 (RUNX2), Osterix, osteocalcin (OCN), and osteopontin (OPN). Immunoprecipitation assay was used to determine the interaction of GRP78 with c-Src. The formation of cellular mineralized nodules was determined by alizarin red staining.
Results: GRP78 was heterogeneously expressed in PDLFs, and GRP78High and GRP78Low subpopulations were obtained by flow sorting. The osteogenic differentiation ability and phosphorylation level of c-Src kinase in the GRP78High subpopulation were significantly increased compared with those in GRP78Low subpopulation after cyclic mechanical stretch (P<0.05). GRP78 interacted with c-Src in PDLFs. The overexpression c-Src group showed significantly increased osteogenic differentiation ability than the vector group (P<0.05), and the sic-Src group showed significantly decreased osteogenic differentiation ability (P<0.05) after cyclic mechanical stretch.
Conclusions: GRP78 upregulates c-Src expression by interacting with c-Src kinase and promotes osteogenic differentiation under cyclic mechanical stretch in PDLFs.
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