2021 Vol.29(8): 505–514    [Abstract] ( )    [RICH HTML ] ( )   [PDF 2033 KB ]( )

Guided bone regeneration technology applied in alveolar bone defect regeneration is based on the barrier function and space maintenance of the barrier membrane. Therefore, traditional development strategies for barrier membranes focus on their physical barrier function, degradation characteristics and biocompatibility to avoid immunogenicity. However, not only does the barrier membrane passively block connective tissue, it is recognized as a “foreign body”that triggers a persistent host immune response, known as a foreign body reaction. The theories of osteoimmunology reveal a close relationship between the immune system and bone system and emphasize the role of immune cells in bone tissue-related pathophysiological processes. Based on these findings, we propose a novel development strategy for barrier membranes based on immune microenvironment regulation: by manipulating mechanical properties, surface properties and physiochemical properties, barrier membranes are endowed with an improved immunomodulation ability, which helps to regulate immune cell reactions to induce a favorable local immune microenvironment, thus coordinating osteogenesis and osteoclastogenesis as well as barrier membrane degradation to increase the efficiency of barrier membranes in GBR applications. In this paper, we review the development of barrier membranes and their close relationship to the immune microenvironment concerning bone regeneration and membrane degradation. Additionally, the outcomes of research on barrier membranes based on the regulation of the immune microenvironment have been summarized to improve the osteogenesis efficiency of barrier membranes and solve the problem of the regeneration and repair of bone defects, especially alveolar bone defects.

2021 Vol.29(8): 515–522    [Abstract] ( )    [RICH HTML ] ( )   [PDF 2290 KB ]( )

Objective To compare the color stability of Biodentine and mineral trioxide aggregate (MTA) within the blood environment in vitro and to further investigate the underlying reasons for such color instability. Methods We first generated Biodentine and MTA discs with a diameter of 5 mm and a height of 3 mm. 24 discs of each material were randomly divided into two groups: the deionized water group and the defibrinated sheep blood group. Discs of each group were immersed for 1 day or 7 days before assessments. First, all discs were photographed to directly compare the discoloration of Biodentine and MTA. The color degree of the two materials was tested by a spectrophotometer. Then, the high-resolution morphological characteristics were observed by scanning electron microscopy. Finally, the chemical contents of each element in the material were measured by energy-dispersive spectroscopy. Results Compared to immediately after stripping, a change in the brightness of discs after immersion in defibrinated sheep blood for 1 day was observed only in MTA. On the 7th day after being immersed in blood, the colors of both the Biodentine and MTA discs darkened and turned deep red, but the darkness of the MTA discs increased significantly. The color change of MTA immersed in blood was measured on a spectrophotometer with a greater 7-day ?E (21.257 ± 0.955) than the Biodentine 7-day ?E (5.833 ± 0.501) (t=24.781, P < 0.001). MTA exhibits more discoloration as the immersion time goes on. A significant difference was noted between the 1-day ?E(6.233 ± 0.888) and the 7-day ?E(t=19.956, P < 0.001) of MTA immersed in blood. However, there was no statistically significant difference between the 1-day ?E (6.790 ± 0.831) and the 7-day ?E(t=1.707, P=0.163) of Biodentine immersed in blood. It was observed by scanning electron microscopy that after 7 days of immersion in the defibrinated sheep ablood, the surface porosity of MTA was larger than that of Biodentine, and the crystal edge of MTA became rounded and blunt. The analysis by energy-dispersive X-ray spectroscopy showed that the oxygen content decreased and the bismuth content increased in MTA after immersion in defibrinated sheep blood for 7 days. Zirconium was not detected in Biodentine due to its low radiodensity, but the contents of other elements were stable in Biodentine after immersion in defibrinated sheep blood for 7 days. Conclusion The color stability of Biodentine within the blood environment is better than that of MTA in vitro, which is mainly related to the low surface porosity and stable composition of the anti-radiation agent of Biodentine.

2021 Vol.29(8): 523–528    [Abstract] ( )    [RICH HTML ] ( )   [PDF 2027 KB ]( )

Objective To compare the efficacy of different methods in the removal of calcium hydroxide from root canals and to provide a reference for clinical treatment. Methods A total of 160 extracted single-rooted mandibular premolars were instrumented up to ProTaper Universal F4. The roots were split longitudinally, and standardized groove and depression models were prepared and filled with calcium hydroxide. The samples were randomly divided into 4 groups (n=40) according to different irrigation methods: syringe needle irrigation, passive ultrasonic irrigation, XP-endo finisher (XPF) irrigation, and M3-Max irrigation. Each group was then divided into 2 subgroups (n=20) according to the irrigation protocol: NaOCl and NaOCl+EDTA. Photos of grooves and depressions were taken under a microscope after irrigation, and the residual calcium hydroxide was scored to compare the removal effects of different irritation methods and solutions. Results In the groove and depression model, when sodium hypochlorite is used as the irrigation fluid, ultrasound irrigation, XPF and M3-Max are better than syringe needle irrigation in removing calcium hydroxide (P < 0.05); when sodium hypochlorite combined with EDTA flushing, the effect of removing calcium hydroxide with ultrasound irrigation, XPF and M3-Max is better than that of syringe needle irrigation (P < 0.05); but there is no statistically significant difference between ultrasound, XPF and M3-Max (P > 0.05); when compared with the use of sodium hypochlorite, the combined use of EDTA irrigation could enhance the effect of ultrasonic irrigation, XPF and M3 Max on the removal of calcium hydroxide (P < 0.05), but there was no significant improvement in the syringe needle irrigation group (P > 0.05). Conclusion Sodium hypochlorite combined with EDTA can enhance the effect of ultrasonic irrigation, XPF and M3 Max on the removal of calcium hydroxide, and there is no significant difference among these approaches, which are more effective than syringe needle irrigation.

2021 Vol.29(8): 529–534    [Abstract] ( )    [RICH HTML ] ( )   [PDF 1018 KB ]( )

Objective To study the effect of p38 mitogen activated protein kinase (p38 MAPK) on the expression of genes related to enamel development in the enamel epithelium and to provide a basis for the study of the molecular mechanism of enamel development. Methods The p38 MAPK-specific inhibitor SB203580 dissolved in DMSO was added to the culture medium of mouse mandibular molar tooth germs in vitro as experiment group, and mouse mandibular molar tooth germs treated with the same amount of DMSO were used as control group. Western blot was used to detect the protein expression level of phosphorylated p38 (p-p38) in the enamel epithelium. Real-time PCR was used to detect the mRNA expression levels of runt-related transcription factor 2 (Runx2), osteoblast-specific transcription factor (Osx), ameloblast markers odontogenic ameloblast associated protein (ODAM), amelotin (AMTN), matrix metalloproteinase 20 (MMP20) and kallikrein 4 (KLK4) in the enamel epithelium. Results Western blot results showed that under the action of the inhibitor SB203580, the phosphorylation level of p38 MAPK in mouse enamel epithelium decreased, and the difference was statistically significant (P < 0.05). Real-time PCR results showed that the expression levels of the transcription factors Runx2 and Osx and the ameloblast markers ODAM, AMTN, MMP20, and KLK4 in the SB203580 group were lower than those in the control group, and the difference was statistically significant (P < 0.05). Conclusion The p38 MAPK signaling pathway can mediate enamel development by regulating the expression of the transcription factors Runx2 and Osx and the ameloblast markers ODAM, AMTN, MMP20 and KLK4 in the mouse enamel epithelium.

2021 Vol.29(8): 535–540    [Abstract] ( )    [RICH HTML ] ( )   [PDF 2276 KB ]( )

Objective To investigate the effect of silencing the endoplasmic reticulum stress-related protein calnexin on the proliferation, invasion, and migration of tongue squamous cell carcinoma cells. Methods Calnexin siRNA was transfected into SCC-9 and SCC-25 tongue squamous cell carcinoma cells, and the expression of calnexin was detected by qRT-PCR. The silencing effect of calnexin siRNA was further verified by Western blotting. CCK-8 assay was applied to detect the effect of silencing calnexin on the proliferation of tongue squamous cell carcinoma cells; Transwell assay was used to detect the effect of silencing calnexin on the invasion and migration of tongue squamous cell carcinoma cells. Results qRT-PCR showed that calnexin siRNA could effectively downregulate the expression of calnexin. Western blot analysis further confirmed the silencing effect of calnexin siRNA on calnexin. The CCK-8 assay showed that silencing calnexin expression on the 4th and 5th days could inhibit the proliferation of tongue squamous cell carcinoma cells, and the difference was statistically significant (P < 0.01). The Transwell assay showed that knockdown of calnexin could inhibit the invasion and migration of tongue squamous cell carcinoma cells (P < 0.001). Conclusion Knockdown of calnexin can inhibit the proliferation, invasion, and migration of tongue squamous cell carcinoma cells.

2021 Vol.29(8): 541–547    [Abstract] ( )    [RICH HTML ] ( )   [PDF 3169 KB ]( )

Objective To investigate the changes in the sagittal diameter of the upper airway before and after the treatment of skeletal Class Ⅲ malocclusion in adults with microimplant anchorage and class Ⅲ intermaxillary elastics and to provide a reference for clinical treatment. Methods A total of 35 adult patients with skeletal Class Ⅲ malocclusion were selected to be treated with the straight-wire technique. Microimplant group, 15 cases (group A): patients with severe skeletal Class Ⅲ malocclusion (vertical high angle) were treated with the straight-wire technique combined with microimplant anchorage; class Ⅲ intermaxillary elastics group, 20 cases (group B): Patients with mild or moderate skeletal Class Ⅲ malocclusion (vertical low angle and average angle) were treated with the straight-wire technique combined with class Ⅲ intermaxillary elastics, and cephalometric radiographs obtained before and after treatment in the upper airway in the two groups were measured and analyzed. Results Changes in cranial and maxillofacial measurements after correction: in group A, (sella-nasion-supramental angle) the SNB angle decreased significantly (P < 0.05), and (subspinale-nasion-supramental angle) the ANB angle increased significantly (P < 0.05). In group B, the SNB angle decreased significantly (P < 0.05), while (subspinale-nasion-subspinale angle) the SNA angle、ANB angle and anterior skull base plane-mandibular plane angle (Sn-MP) angle increased significantly (P < 0.05). Changes in sagittal diameter of the upper airway measurements after corrections: In group A, the width of the glossopharyngeal segment of the upper airway (TB-TPPW) decreased significantly (P < 0.05). In group B, first segment width of the upper airway behind the hard palate (PNS-R) increased significantly (P < 0.05). After correction, the decreased SNB and increased ANB in group A was higher than that in group B, and the difference was statistically significant （P < 0.05）. The decreased of TB-TPPW in upper airway of group A was greater than that of group B, and the difference was statistically significant （P < 0.05）. Conclusions In the treatment of skeletal class Ⅲ malocclusion with microimplant anchorage, the sagittal diameter of the glossopharyngeal segment of the upper airway has a negative impact.

2021 Vol.29(8): 548–552    [Abstract] ( )    [RICH HTML ] ( )   [PDF 2520 KB ]( )

Objective To explore the feasibility of curettage combined with fenestration for jaw classic ameloblastoma treatment and to provide a basis for improving the treatment of classic ameloblastoma. Methods Twenty-two patients with jaw classic ameloblastoma admitted to Liuzhou People’s Hospital from 2016 to 2019 were selected. They were treated by curettage combined with fenestration. Monthly follow-up visits were conducted after surgery, and orthopantomography was performed for reexamination to observe the recovery of bone and whether there was recurrence. Results Tumors were completely scraped off in 22 patients, no pathological fracture occurred, and no wound infection occurred after surgery. After 1 to 3 years of follow-up, 19 patients showed excellent bone recovery in the original tumor area, and no recurrence was observed. Three patients relapsed and underwent a second curettage combined with fenestration, and the bone at the original tumor site recovered well. During the 12-month follow-up, no tumor recurrence was observed. After the second curettage combined with open surgery, the bone at the original tumor site recovered well. Eight patients underwent dental implants to repair dentition defects one year after surgery. Conclusion Curettage combined with fenestration is a convenient and effective treatment for jaw classic ameloblastoma.

2021 Vol.29(8): 553–556    [Abstract] ( )    [RICH HTML ] ( )   [PDF 745 KB ]( )

Objective To analyze the oral adverse drug reactions induced by omeprazole and provide a reference for rational clinical drug use. Methods From January 2019 to June 2020, the clinical data of patients with burning mouth syndrome caused by omeprazole were collected and analyzed. Additionally, the related literature was reviewed. Results Among the six patients, omeprazole was taken orally for as little as 6 months and as long as more than 5 years. The symptoms of burning mouth syndrome were mainly burning sensation in the mouth and paresthesia on the tongue that might be accompanied by extremity numbness. Vitamin and trace element supplementation was administered. The patient discontinued omeprazole, and symptoms disappeared after symptomatic treatment for 1 month to half a year. Literature review suggests that the reason may be associated with peripheral or central nervous system injury, altered saliva composition, and impaired vitamin and micronutrient intake caused by omeprazole. Conclusion The cause of burning mouth syndrome-like symptoms may be related to peripheral nerve injury caused by omeprazole and saliva changes. The main treatment is withdrawal and symptomatic treatment.

2021 Vol.29(8): 557–561    [Abstract] ( )    [RICH HTML ] ( )   [PDF 776 KB ]( )

Periodontitis is an infectious disease caused by a variety of microorganisms. Fusobacterium nucleatum is closely related to periodontitis with a high detection rate. Fusobacterium nucleatum is able to coaggregate with other microorganisms and attach and invade epithelial cells with the help of adhesins. It can also promote the occurrence and development of periodontal diseases and even systemic diseases by destroying periodontal tissues with virulence factors and metabolites and inducing a host immune response. However, at present, drugs assisting periodontal nonsurgical treatment clinically cannot target specific periodontal pathogens, such as Fusobacterium nucleatum, which may lead to problems such as dysbacteriosis or drug resistance. Therefore, studies on the pathogenic mechanism of Fusobacterium nucleatum provide new ideas for the prevention and treatment of periodontitis. The idea is to develop materials, drugs, or probiotics that target adhesins, virulence factors, and metabolites or cut off each pathogenic pathway of Fusobacterium nucleatum to inhibit its proliferation and inflammatory responses in deep periodontal pockets and achieve a balance with other oral microorganisms, and the host is beneficial for the control of periodontitis.

2021 Vol.29(8): 562–566    [Abstract] ( )    [RICH HTML ] ( )   [PDF 767 KB ]( )

Periodontitis is a chronic inflammatory disease that is initiated by bacteria. Pathogens and their virulence factors alter normal cellular metabolic activity and deteriorate periodontal microconditions. Owing to the complexity of tooth structure and the limitation of conventional treatment, we may not live up to all patients’ expectations, especially those with grade C and stage Ⅲ or Ⅳ periodontitis. With the advantages of bactericidal effects, high safety, inhibition of bacterial drug resistance and promotion of tissue healing, photodynamic therapy （PDT） seems to be an ideal technology in periodontal treatment. However, it cannot remove subgingival stones and still cannot replace mechanical treatment to preliminarily control periodontal inflammation. Therefore, near-infrared low-energy light combined with traditional photosensitizers is mostly used in clinical periodontal adjuvant treatment. In periodontal maintenance treatment on a regular basis, a single application can also reduce the sensitivity of patients and effectively control plaque, but its effect will be affected by the degree of periodontal inflammation, the concentration and type of photosensitizer, the energy of the light source, etc. With the further development of material science, the performance of photosensitizers to accelerate oxides and target bacteria will be optimized. In the future, parameters of PDT need to be designed in large-scale studies in accord with different stages and grades of periodontitis.

2021 Vol.29(8): 567–571    [Abstract] ( )    [RICH HTML ] ( )   [PDF 771 KB ]( )

Mucositis is the most common side effect of radiotherapy and chemotherapy. It is an inflammatory disease with an unclear pathogenesis, diverse clinical manifestations and no effective treatment. It often manifests as local mucosal burning and stinging pain in the oral cavity and nausea, vomiting and diarrhea in the gastrointestinal tract. At present, it has been found that local microflora imbalance promotes the occurrence and development of chemoradiotherapy mucositis, and probiotics can be used as an emerging approach to prevent and treat mucositis. This paper reviews the research progress of probiotics in the prevention and treatment of oral and gastrointestinal chemoradiotherapy mucositis, focusing on the influence of microorganisms on the pathogenesis and treatment of gastrointestinal mucositis. Literature review results showed that the occurrence and development of mucositis may be related to changes in the composition and function of local microflora, and probiotics can play a preventive role by regulating local microecology and host immunity. At present, the main probiotics used in the prevention and treatment of mucositis are Lactobacillus and Bifidobacterium. Most clinical trials have confirmed that probiotics have a positive effect in the prevention and treatment of mucositis. However, due to the variety of probiotics and different tumor treatment regimens, prevention and treatment effects may not be observed in some studies. Therefore, the selection of probiotics with high efficacy and safety and the design of the best combination of probiotics and intervention programs are current research hotspots.

2021 Vol.29(8): 572–576    [Abstract] ( )    [RICH HTML ] ( )   [PDF 772 KB ]( )

Acute lymphoblastic leukemia is the most common type of leukemia in children. In recent years, the treatment and prognosis of acute lymphoblastic leukemia in children have improved significantly. However, acute lymphoblastic leukemia itself and treatment measures can lead to a variety of adverse oral complications and affect further treatment. These complications have a significant effect on patients and affect further treatment. To improve the quality of life of children, this article reviews the oral health status and oral health management of children with acute lymphoblastic leukemia for clinical reference. The literature review shows that the oral health management measures for children with acute lymphoblastic leukemia mainly include oral health education, active prevention of oral diseases, timely oral treatment before the start of antitumor treatment, elimination of potential sources of infection after blood examination and risk assessment, treatment of oral mucosal problems during therapy, oral emergency during antitumor therapy should be carried out under the guidance of hematologists and regular oral inspection and oral care. However, current studies have found that there is still a lack of effective prevention and treatment measures for oral mucositis. As a common oral disease in children with acute lymphoblastic leukemia, the prevention and treatment of oral mucositis remain to be further studied.