Vital pulp therapy aims to maintain healthy pulp tissue as much as possible to improve the long-term survival of teeth. It has limited indications and uncertain curative effects. The pathological changes in inflamed pulp are the histological basis for the determination of treatment strategies and the treatment outcome; however, pulp sensitivity testing cannot reflect the actual histological status of the pulp. With the development of basic and clinical research on vital pulp therapy, the innovation of modern diagnostic and therapeutic technology and capping material, vital pulp therapy can be used as a treatment of teeth on which it was previously thought pulpectomy was necessary. Based on the evidence-based literature, this paper analyzes and summarizes the pathological changes of pulpitis and clinical research on the treatment of pulpitis. Vital pulp therapy can be a treatment for mature teeth with carious exposure and symptoms of irreversible pulpitis if comprehensive applications, including laser Doppler flowmetry, tissue oxygen monitoring, magnetic resonance imaging and microscopy, are used to determine the degree of pulp retention and if infection control and the use of biocompatible capping material are emphasized. In the future, it will be necessary to improve the success rate of vital pulp therapy for the treatment of pulpitis through research on the mechanism of pulp repair and regeneration, the precise diagnosis of pulpitis, and the development of pulp capping materials.
Objective To investigate the effects of platelet-rich fibrin (PRF) and acellular dermal matrix (ADM) on the repair of oral mucosal defects and to provide the basis for soft tissue growth in oral implant operations.Methods Thirty-six healthy male Japanese big ear rabbits were randomly divided into the PRF group, ADM group, Autograft group (autologous connective tissue transplantation group) and Control group (blank control group); each group contained nine rabbits. Between the midline and the hard palate maxillary incisors, in an 8-mm location preparation and a 10-mm standard mucosa defect, the ADM group, PRF and Autograft group were implanted with ADM, autologous PRF and autologous cornification mucosa, respectively, whereas the control group had wound gauze compression processing at 7, 14, and 21 days to determine the wound healing rate in the area selected by HE staining. The inflammatory grade and average epithelial thickness were observed, and the results were statistically analyzed.Results Compared with the control group, the PRF, ADM and Autograft groups had significantly advanced wound healing (P < 0.05). The wound healing degree in the PRF group was similar to that of the ADM group at all time points (P > 0.05). The wound healing degree in the PRF and ADM groups was lower than that of the Autograft group at each time point (P < 0.05). HE staining results showed that compared with the control group, the levels of inflammation in the PRF group, ADM group and Autograft group were reduced, and the difference was statistically significant (P < 0.05). Nevertheless, there was no significant difference between the PRF, ADM and Autograft groups (P > 0.05). The epithelial thickness in the ADM group was similar to that in the Autograft group (P > 0.05). The epithelial thickness in the ADM group was higher than that in the PRF group at 7 d and 14 d (P < 0.05), but there was no significant difference at 21 d (P > 0.05).Conclusion PRF and ADM have similar healing effects in repairing oral mucosa defects, and they can be used as soft tissue augmentation materials instead of connective tissue transplantation.
Objective To investigate the level of hypoxia inducible factor-1α (HIF-1α) on osteoblasts and angiogenesis-associated cytokines in bone marrow mesenchymal stem cells (BMSCs) from SD rats.Methods BMSCs were isolated and cultured and identified by flow cytometry. Plasmid vectors containing upregulated and downregulated HIF-1α gene and a control vector were constructed. The plasmids were transfected into BMSCs by Lipofectamine?LTX transfection reagent, and the cells were divided into an overexpression experimental group, an overexpression control group, a low expression experimental group and a low expression control group. All components were stained with a lizarin red 3 d and 7 d after osteogenesis induction. The mRNA expression levels of the target gene HIF-1α, osteogenic differentiation-specific markers, including Runt-related transcription factor 2 (Runx2) and angiogenic markers, including platelet-derived growth factor-BB (PDGF-BB) and transforming growth factor-β (TGF-β), were detected by RT-PCR. Western blot was used to detect the protein expression of the target proteins HIF-1α, Runx2, and PDGF-BB.Results The CD29- and CD45-positivity rates of BMSC surface markers identified by flow cytometry were 98.2% and 4.2%, respectively. RT-PCR results showed that the mRNA expression of HIF-1α, Runx2, TGF-β and PDGF-BB was observably increased (P < 0.001). The mRNA expression levels of HIF-1α, Runx2, TGF-β and PDGF-BB in BMSCs from the low expression experimental group were significantly reduced (P < 0.001). Western blot results showed that the expression levels of HIF-1α, Runx2 and PDGF-BB in BMSCs from the overexpression experimental group were all increased (P < 0.001). The expression levels of HIF-1α, Runx2 and PDGF-BB in BMSCs from the low expression experimental group were reduced (P < 0.001). Alizarin red staining results showed that the area of calcium nodules in the low expression experimental group was smaller than that in low expression control group, the area of red calcium nodules in the over expression experimental group was larger than that in over expression control group, and with the increase of osteogenic induction time, the calcification area of each group also increased.Conclusion Upregulation and downregulation of HIF-1α can regulate the osteogenic differentiation and the expression of angiogenesis related factors of BMSCs.
Objective To evaluate the effect of different surface treatments on the bonding strength between highly translucent zirconia and veneering porcelain and to provide a research basis for improving the zirconium porcelain bond strength between zirconium and ceramic material.Methods Thirty cylindrical zirconia blocks with 10-mm diameter and 10-mm height were prepared and divided into four groups (n=7), labeled as control group (C), sandblasting group (S), bonding group (B), and sandblasting and bonding group (SB). The surface morphology of zirconia before and after sandblasting was observed in the remaining two specimens. Group C was veneered (2 mm in height and 5 mm in diameter) with porcelain powder by layering after grinding. Group S was sandblasted after grinding. Group B was veneered with a thin layer of porcelain powder as bond coating. Group SB was sandblasted and veneered with a thin layer of porcelain powder. After sintering, the shear specimens were embedded, and a shear bond strength test was conducted. Statistical analysis was conducted to analyze the data. Fracture surface analysis was also performed to determine the failure modes by stereomicroscopy.Results The bonding strength of group C was 21.86 ± 3.18 MPa. For group S, it was 22.12 ± 3.06 MPa. For group B, it was 19.19 ± 1.46 MPa. Finally, for group SB, it was 27.76 ± 1.95 MPa. There was no significant difference in shear strength between group C, group S and group B. There was a significant difference in shear strength between each group and group SB (P < 0.05). Under a stereomicroscope, the observed fracture modes of each group were mainly mixed failure.Conclusion Sandblasting cannot significantly increase the bonding strength between zirconia and veneering porcelain. Veneering with a thin layer of porcelain powder as the bond coating has no obvious effect on the bonding strength. Sandblasting and veneering with a thin layer of porcelain powder as a bond coating can significantly improve the bonding strength between zirconia and veneering porcelain.
Objective To investigate the inhibitory effect of baicalin on Streptococcus mutans UA159 in vitro.Methods The minimum inhibitory concentration (MIC) of baicalin on Streptococcus mutans UA159 was determined by the liquid multiple dilution method combined with the OD600 value measured by microplate. The OD600 value of Streptococcus mutans UA159 in different concentrations of baicalin was measured by an enzyme mapping instrument. A growth curve was drawn, and the adhesion rate and adhesion inhibition rate were calculated. The effect of baicalin on the formation of Streptococcus mutans UA159 biofilms was observed by the crystal violet quantitative method and scanning electron microscopy. The effect of baicalin on the total number of Streptococcus mutans UA159 bacteria was observed by scanning electron microscopy.Results The MIC of baicalin on Streptococcus mutans UA159 was 12 mg/mL. With increasing baicalin concentration, the growth rate of Streptococcus mutans UA159 was slowed, the adhesion rate of Streptococcus mutans UA159 decreased and the adhesion inhibition rate increased（P < 0.05）. The results of crystal violet quantitative method showed that compared with the bacterial control group, the biofilm formation of Streptococcus mutans UA159 was significantly reduced after adding baicalin at 0 h, 6 h and 12 h (P < 0.001). Under a scanning electron microscope, the total number of bacteria decreased significantly after adding baicalin at 0 h, 6 h and 12 h.Conclusion Baicalin can inhibit the growth and reproduction of Streptococcus mutans UA159 in vitro as well as the adhesion and biofilm formation of Streptococcus mutans UA159.
Objective To investigate the difference of the temporomandibular joint between patients with anterior open-bite and normal overbite with cone beam CT (CBCT).Methods Fifty-four patients with anterior open bites and 54 patients with normal overbites were selected from the Department of Orthodontics, Nanjing Stomatological Hospital, Medical School of Nanjing University from June 2014 to August 2020. Sagittal and coronal images of the temporomandibular joint were reconstructed with multiplanar reconstruction techique. The Kamelchuk method was used to measure the superior, posterior and anterior space of the temporomandibular joint, and the condylar morphology was divided into two types: normal and abnormal. The joint space and condylar morphology of the anterior open-bite group and the normal overbite group were statistically analyzed. The anterior open-bite group was divided into 3 subgroups: ① Ⅰ° open-bite (open bite distance < 3 mm), ② Ⅱ° open-bite (open bite distance ≥ 3 mm and ≤ 5 mm) and ③ Ⅲ° open-bite (open bite distance > 5 mm). The difference of overbite spaces of the temporomandibular joint was compared among these three subgroups.Results Compared to the normal group, no significant differences were found for the anterior and superior space of the temporomandibular joint in the anterior open-bite group (P > 0.05), but the posterior space increased significantly (P < 0.01). A total of 52.8% of patients in the anterior open-bite group had abnormal condyles, whereas 21.3% of patients in the normal group, overbite significant differences was found between the two groups (P < 0.01). Compared with patients with Ⅰ° and Ⅱ° openbite, the condyle of patients with III° open bites was more forward in the fossa (P < 0.05).Conclusion The position of the condyle in the fossa of patients with anterior open bites is more forward, and abnormal condylar bone is more common found.
Objective To evaluate the value of Kirschner wire internal fixation in the treatment of sagittal mandibular condylar fractures.Methods From January 2019 to January 2020, 13 patients (19 sides) with mandibular condylar sagittal fracture treated by Kirschner wire internal fixation at the Stomatological Medical Center, Foshan Hospital of Traditional Chinese Medicine were retrospectively analyzed. After conventional surgical incision and exposure and reduction of the mandibular condyle, 2-4 Kirschner wires were used for fixation, and other maxillofacial fractures were treated simultaneously. The reduction accuracy and stability of the free mandibular condyle were evaluated by CBCT one week after the operation, and the occlusion relationship, opening degree and opening type were evaluated by clinical examination.Results All patients had good fracture alignment and no twisting, breaking or loosening of the Kirschner wire. The occlusion relationship, opening degree and opening shape recovered well after the operation.Conclusion Kirschner wire is effective in treating sagittal fractures of mandibular condyles.
Objective To explore the technology and efficacy of fabrication of a guide and removal of a fiber post by tetrahedron positioning technology at the chair side.Methods For one patient with acute chronic periapical periodontitis of the left maxillary lateral incisor who needed to have the fiber post removed, the chair side tetrahedral positioning technique was used to make a guide plate to remove the fiber post. Cone beam CT (CBCT) data were imported into the software to design the guide plate for fiber post removal. The guide plate design on CBCT was transferred to a solid model by using tetrahedral positioning technology. The guide plate was made to guide the removal of the fiber post, and then left maxillary lateral incisor root canal was performed. We evaluated the effect of fiber post removal with tetrahedral positioning technology by reviewing the literature.Results The guide plate made by tetrahedral positioning technology can accurately locate the position and direction of fiber posts at a low cost and with high speed. After the fiber post was removed, the root canal could be dredged by using root canal preparation instruments. After root canal preparation, the root canal was filled with warm gutta-percha to complete the root canal treatment. After 3 months, the apical radiograph showed that the transmission shadow of the apical area was reduced. The results of the literature review showed that the fiber post removal with guide plates provides a predictable result and a lower risk of iatrogenic damage. Minimally invasive treatment can be carried out, and chair time can be reduced.Conclusion On the basis of CBCT data, using tetrahedral positioning technology to make fiber post removal guides can help reduce the risk of fiber post removal and has the characteristics of speed, low cost and short chair side processing. However, the accuracy comparison between tetrahedral positioning technology and 3D printing guides needs further study.
Chronic periodontitis is an infectious disease caused by plaque as the initiating factor. Clinically, it manifests as irreversible loss of hard tissue, leading to the destruction of surrounding periodontal tissue, including the deep periodontal pocket, loss of attachment, and finally, tooth loss. Interleukin-18 (IL-18) can promote inflammation and regulate immune function and plays an important role in mediating the host immune response and inflammatory response. An increase in IL-18 in vivo can induce the production of interferon and inflammatory factors, such as interleukin, tumor necrosis factor and matrix metalloproteinase, thus mediating the dual reaction of immunity and inflammation. These inflammatory factors are involved in the occurrence and development of chronic periodontitis. Many clinical studies have shown that the levels of IL-18 in serum, saliva, gingival crevicular fluid and gingival tissue samples of patients with chronic periodontitis may be positively correlated with the severity of periodontitis; however, as a candidate gene, IL-18 is involved in the susceptibility polymorphism of periodontitis. Understanding how to quantify the level of IL-18 in clinical studies and apply it to diagnostic tools and new sites identified by new methods (genome-wide association studies and omics research) will also deepen our understanding of the pathogenesis of IL-18 in chronic periodontitis and provide new ideas for future precision medicine and the formulation of personalized programs. In this paper, the structure, biological function and association between IL-18 and periodontitis are reviewed.
Malignant tumors in the head and neck seriously threaten the physical and mental health of patients. After treatment, they may cause many complications, such as facial deformity, difficulties with chewing, dysphagia and asaphia. Among them, trismus (restricted mouth opening) is one of the most common complications after treatment of malignant oral-maxillofacial tumors. In severe cases, patients may even suffer from trismus and eating difficulties, finally leading to malnutrition and even cachexia. Therefore, it not only affects the quality of life of patients and even endangers their lives but also brings heavy social and economic burdens. How to effectively prevent and treat posttreatment trismus is a clinical problem that is easily ignored by head and neck surgeons and urgently needs to be solved. The results of a literature review showed that trismus may be related to the tumor clinical stage, tumor site, treatment used, radiotherapy site, radiotherapy dose, radiotherapy type, and other factors. The incidence of trismus tends to be significant 6 months after treatment. Without early intervention, the resulting dysfunction may become more severe. Current studies have shown that the prevention and treatment of restricted mouth opening is based on controlling the progress of restricted mouth opening and restoring function. Exercise intervention for trismus can significantly improve the restricted mouth opening of patients with malignant head and neck tumors after treatment.
As a minimally invasive procedure, micro-osteoperforations (MOPs) achieve desired therapeutic effect with minimal surgical intervention. The operation is relatively simple, and the effect of assisted orthodontic treatment is obvious. However, due to the lack of long-term follow-up studies, there is no unified consensus on the long-term stability of the procedure. This article reviews the research status of MOPs, biological and biomechanical mechanisms, clinical applications and limitations. MOPs can shorten orthodontic treatment time and accelerate tooth movement by exerting regional acceleratory phenomena (RAP). At the same time, this procedure will not damage the health of the periodontal tissue, and the postoperative bleeding and postoperative reaction are minor. In addition, the pain and discomfort of patients were relatively mild and acceptable. However, it also has limitations, mainly including the limited time of the RAP effect of MOPs. Although this procedure is a minimally invasive surgery, there is still a risk of treating regional bone defects. At present, it is still necessary to increase the sample size and extend the follow-up time to evaluate the long-term stability of MOPs.
Peripheral nerve injury (PNI) is a common disease in the oral cavity that can easily lead to loss of function and abnormal appearance. The application of dental pulp stem cells (DPSCs) combined with tissue engineering in the repair of PNI is a research hotspot. DPSCs have the advantages of abundant sources, simple extraction, low immunogenicity and a high proliferation rate in vitro. They can differentiate into Schwann cells (SCs). SCs can induce autophagy and secrete key neurotrophic factors, such as nerve growth factor, brain-derived neurotrophic factor, ciliary neurotrophic factor and glial cell-derived neurotrophic factor. SCs are beneficial for the repair of nerve injury. DPSCs in different periods have differences in immune regulation, anti-inflammatory effects, expression of neural markers, angiogenesis and so on, which provide more diversified choices for nerve repair. At present, the introduction of tissue engineering provides a more controllable and improved microenvironment for DPSCs, which is conducive to the application and development of DPSCs in regenerative medicine and tissue engineering. However, there are still many problems to be solved, such as the selection of stem cells, functional link recovery, uncontrollable direction of axon regeneration, regulation of the peripheral nervous system and mechanism of repair.
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