The nature, significance, parameters, influencing factors and testing of implant primary stability were studied by a literature review. Primary stability is a kind of anchorage force at the interface between the implant and bone, and it is merely mechanical. The significance of primary stability is to keep the implant unmovable so that the new bone can grow undisturbed on the surface of the implant without interference from fibrous tissue. The implant is finally bound to the bone by osseointegration. The most common assessments of primary stability are insertion torque (IT), the implant stability quotient (ISQ) of the resonance frequency analysis (RFA) and Periotest. IT is more commonly used to directly imply initial stability. At present, no consensus has been reached regarding the concrete parameters of primary stability to predict osseointegration. Implant osseointegration could be developed through all phases of primary stability. However, the excessive primary stability would cause mini-bone fractures, followed by bone necrosis at the interface and the final failure of implantation. Primary stability is influenced by three factors: implant design, bone condition of alveolar bone, and surgical technique. Under the condition of a lack of primary stability and immediate implantation, there may be the possibility of successful osseointegration. Therefore, it is necessary to re-examine the accuracy of the current elaboration on the primary stability. It is related directly to whether the clinic can choose the appropriate implant treatment path.
Root canal isthmus(RCI) is defined as a narrow, ribbon-shaped communication between two root canals that contains pulp or tissue derived from pulp. Any root that contains two or more root canals has the potential to contain an isthmus. The incidence of RCI from different tooth positions varies, with the highest RCI incidences usually found in the mesial root of the mandibular first molar and the mesiobuccal root of the maxillary first molar. The presence of RCI increases the difficulty of root canal therapy and introduces uncertainty regarding the prognosis for dental treatment. It is recommended to use CBCT and dental microscopy to identify teeth with suspected RCI in clinical practice. At the same time, for treatment of teeth with RCI, appropriate instruments should be selected, and enhanced root canal irrigation assisted by ultrasound should be considered to improve the success rate of root canal treatment and endodontic root-end surgery. The current technology still has some limitations regarding the cleaning and filling of RCI and additional research and development. Improvement of the corresponding technology and equipment is a current research hotspot and a future research direction.
Objective To investigate the in vitro interaction of amphotericin B (AmB) and fluconazole (FLC) at different time points and provide a reference for clinical combined treatment therapy of polyenes and azoles. Methods Candida albicans ATCC SC5314 was used in the study. The minimum inhibitory concentration (MIC) of antifungal drugs was determined using the double microdilution broth method. The same amount of DMSO and low concentration drugs were added to the DMSO treatment group at different time points (0, 2, 4, 6 h) to determine whether the solvent background environment affected the growth of Candida albicans. In the experimental group, to observe the effect of low concentration AmB on the antifungal effect of FLC, the experimental group was administered a low concentration of AmB (0.25 μg/mL or 0.125 μg/mL) added to FLC at different time points (0, 2, 4, 6 h), and the same amount of DMSO was added to FLC at different time points in the single drug control group. In the experimental group, to observe the effect of low concentration of FLC on the antifungal effect of AmB, the experimental group was administered a low concentration of FLC (0.06 μg/mL or 0.03 μg/mL) in AmB at different time points (0, 2, 4, 6 h), and the same amount of DMSO was used at different time points as the single drug control group. In the solvent group, the same amounts of DMSO and low concentration drugs were added at different time points. After resuscitation, the colony growth of each solvent control group, single-drug control group and experimental group was observed to evaluate the interaction between drug concentration and time. Compared with the AmB single-drug control group, there was no significant change in the experimental group with added low concentrations of FLC at 0 h (F=0.27, P=0.775), which was 1.74-1.93 times that of the control group at 2-4 h (P < 0.001), and there was no significant difference in colony count after 6 h (P > 0.05). Results Under the treatment of FLC at an inhibitory concentration (0.25 μg/ml), adding low concentration AMB did not affect the antifungal effect of FLC, and the multiple of colony count differences were not significant (P > 0.05). Conclusion The interaction between AmB and FLC was time-dependent. At the early stage (0 h), the interaction effect between fluconazole and amphotericin B was not clear. The fungicidal effect of AmB could be weakened when FLC was supplied at 2-4 h, and the effect of FLC on AmB was absent after 6 h.
Objective To analyze the differentially expressed genes of patients with oral squamous cell carcinoma (OSCC) from paracarcinoma through biological information analysis to preliminarily identify OSCC-associated genes. Methods GSE23558, GSE37991 and GSE30784 were downloaded from the Gene Expression Omnibus (GEO), which is the mRNA expression profile dataset. The differentially expressed genes (DEGs) were identified based on the gene ontology and the Kyoto Encyclopedia of Genes and Genomes. Then, the protein-protein interaction (PPI) network was constructed using the STRING online tool, and Cytoscape was used to filter the critical genes. Furthermore, key genes involved in the survival of patients with OSCC were analyzed using Kaplan-Meier analysis. The expression of hub genes was validated based on GEPIA（http://gepia.cancer-pku.cn/）. Results A total of 212 DEGs were screened, and further analysis revealed 16 core genes, among which the core genes associated with prognosis included aurora kinase A (AURKA), aurora kinase B (AURKB), apoptosis inhibiting factor 5 (BIRC5), cell division cycle 6 (CDC6), E2F transcription factor 7 (E2F7), ubiquitin-like with PHD and ring finger domains 1 (UHRF1). These key genes were highly expressed in patients with oral squamous cell carcinoma, and the survival time of patients was short; the difference was statistically significant (P < 0.05). Conclusion AURKA, AURKB, BIRC5, CDC6, E2F7 and UHRF1 may be useful as potential biomarkers for OSCC prognosis prediction.
Objective To explore the clinical effect of bulk-fill composite resin combined with transparent preformed crowns for aesthetic restoration of deciduous incisor of children. Methods A predesigned clinical prospective randomized controlled research method was used to select 90 patients (123 teeth). The random number table method was divided into three groups: A, B, and C. Group A was treated with a bulk-fill composite resin of SF (SonicFill) combined with a transparent preformed crown (41 teeth in 30 cases), and group B was treated with a large block of Tetric N-Ceram Bulk Fill Composite resin combined with transparent preformed crowns (39 teeth in 29 cases). Group C was treated with 3M Z350 XT universal nano resin combined with transparent preformed crowns (43 teeth in 31 cases). The visual analog scale (VAS) and the modified USPHS standard were used to evaluate the completeness, marginal steps, marginal discoloration, surface condition, secondary caries and satisfaction of the parents with prostheses after 12 months. Results Twelve months after the operation, the evaluation indexes of group A were better than those of group B and group C, and the differences were statistically significant, including edge integrity (χ 2=10.847, P=0.028), edge step (χ 2=7.799, P=0.020), edge discoloration (χ 2=10.391, P=0.034), surface state (χ 2=11.476, P=0.021), and secondary caries (χ 2=10.447, P=0.034). The satisfaction of parents in group A on the overall contour (χ 2=10.238, P=0.037), shape and texture (χ 2=11.521, P=0.021) were better than those in group B and group C, and the differences were statistically significant. There was no significant difference in the evaluation of color satisfaction among the three groups (χ 2=0.990, P=0.610). Conclusion SonicFill bulk-fill composite resin combined with transparent preformed crown is good for short-term aesthetic restoration of deciduous incisor, and parental satisfaction is high.
Objective To investigate the clinical efficacy of cevimeline as a pharmacotherapeutic approach to stimulating gland activity in improving the symptoms and signs of primary Sj?gren syndrome (pSS). Methods Sixty-three patients diagnosed with pSS who attended the Affiliated Huai'an Hospital of Xuzhou Medical University from January 2018 to September 2019 were included in this trial. They were randomly assigned to the therapeutic group and control group. All patients were recalled at baseline and after 2 weeks, 3 months and 6 months. Measurement of salivary and lacrimal flow as well as evaluation of subjective symptoms was performed at the follow-up. Results Fifty-eight patients completed the trial and were included in the statistical analysis. There was a significant difference between the two groups in the measurement of salivary and lacrimal flow at the second week and third month (P < 0.05). Improvement in subjective symptoms of oral, ocular and gland was detected at the third month (P < 0.05). At the sixth month, compared with the control group, only the salivary gland symptom score of the treatment group was statistically significant (P < 0.05). Conclusion Cevimeline has good specificity and safety and can increase salivary and lacrimal flow and improve subjective symptoms of pSS in a short time.
Objective To investigate the influence of abnormal occlusion factors on the incidence of temporomandibular disorders (TMDs) in junior college students and to provide an etiological basis for the prevention and treatment of TMDs. Methods We examined the temporomandibular joint (TMJ) and dental occlusion in 754 lower grade college students (male 354, female 400) at Zunyi Medical University (Zhuhai campus). A questionnaire was also administered. We analyzed the correlation between TMD and the other three factors (static abnormal occlusion, dynamical abnormal occlusion and oral parafunctional activity) from the perspective of multivariate unconditioned logistic regression and univariate unconditioned logistic regression with dummy variables. Results The prevalence of TMD was 31.7%. The incidence of TMD was significantly (P<0.05) associated with sleep bruxism (OR=2.070), clenching (OR=2.553), diurnal (OR=2.642) and anterior teeth overbite (OR=1.228). Univariate unconditioned logistics regression analysis by dummy variables was used to analyze the incidence of TMD at different deep overbites (mild, OR=1.558; moderate, OR=2.189; severe, OR=3.236; P<0.05). Conclusion The risk factors for TMD in lower grade college students included anterior teeth occlusion, sleep bruxism, clenching, and diurnal treatment. Worse deep overbite might increase the risk of TMD.
Objective To assess the effect of caries management based on risk assessment in children and to provide the basis for the government to develop strategies to prevent and treat oral diseases. Methods From March 2018 to March 2019, 512 3-year-old children and 502 6-year-old children were selected by cluster sampling from kindergartens and primary schools, respectively, in the Minhang district of Shanghai, and oral examinations and questionnaires were carried out to assess baseline status. Then, the children were divided into 3 groups, including low-, middle- and high-risk groups, according to caries risk assessment. In each caries risk group, the children were randomly divided into an experimental group and a control group. The experimental groups were managed by risk assessment, and the control groups were provided basic oral public health services by the Shanghai government. The effect of caries prevention was evaluated 12 months later. Results Among the children with a high risk of caries, the incidence of caries was 51.22% in the 3-year-old control group, 34.17% in the experimental group, 51.27% in the 6-year-old control group and 33.15% in the experimental group, with statistical significance (P < 0.05). Among the children with a middle risk of caries, the incidence of caries was 38.71% in the 3-year-old control group and 7.32% in the experimental group, with statistical significance (P < 0.05). However, there was no significant difference in caries incidence between the control group and the experimental group for the children with low risk in the 3-year-old or 6-year-old groups and middle risk caries risk in the 6-year-old group. Both 3-year-old and 6-year-old children in the experimental group had a lower risk of caries than those in the observation group in 2019. Conclusion The caries prevention effect is remarkable in high-risk children, and caries management by risk assessment is probably recommended for children with high caries risk.
The jaw and femur are commonly used sites in basic research for modeling bone defects or inserting implants. An increasing number of studies have identified that the jaw and femur indeed show great differences in embryonic development and growth, histomorphology and bone metabolism. A literature review showed that, compared with the femur, the main osteogenic pathway of the jaw may have better osteogenic ability, and its stem cells have better proliferation and osteogenic differentiation ability. However, the jaw structure is less regular, the osteogenic differentiation ability of its osteoblasts is mineralization slightly weak, and the immune cells of the jaw are more sensitive to cytokines. These may be the reasons why the osseointegration of the jaw implant is different from that of the femur in animal experiments, but its specific mechanism has not been clarified.
Nonsyndromic cleft lip with/without cleft palate is a common congenital birth defect of the maxillofacial region. The pathogenic mechanism is related to the interaction of genes and environmental factors. At present, there are many studies on genes, and genome-wide association analysis has found that the new susceptibility gene v-maf musculoaponeurotic fibrosarcoma oncogene homolog B (MAFB) is associated with the development of nonsyndromic cleft lip with/without cleft palate. This paper reviews the research progress on the correlation between single nucletide polymorphism(SNPs) in MAFB and nonsyndromic cleft lip with/without cleft palate. The results of this review reveal how the MAFB gene is expressed and differentiated in various cell types and plays an important role in maintaining the development of various organs, such as the brain, pancreas, and parathyroid glands. The MAFB gene is significantly associated with the occurrence of nonsyndromic cleft lip with/without cleft palate in the Asian population. rs13041247, rs11696257, rs17820943 and other teratopoietic single nucleotide loci are the most commonly studied teratopoietic single nucleotide loci, and the research conclusions on the correlation between SNPs in MAFB genes are obviously different in different populations. The interaction between the MAFB gene and other susceptibility genes leads to the occurrence of nonsyndromic cleft lip with/without cleft palate; nevertheless, more in-depth research is needed on specific mechanisms and approaches based on the relationship between these two factors.
Oropharyngeal carcinoma is a highly heterogeneous disease that is mainly caused by tobacco and alcohol abuse or high-risk human papillomavirus (HPV) infection. HPV-positive oropharyngeal carcinoma and HPV-negative oropharyngeal carcinoma have obvious differences in etiology, epidemiology and prognosis; therefore, different methods should be adopted for treatment. It is known that the TP53 gene is not mutated in HPV-positive oropharyngeal carcinoma, and radiation therapy can activate it and induce cell apoptosis via DNA damage. There are common repair pathways to DNA damage, such as nonhomologous end joining, and this pathway is more sensitive to radiotherapy under the inhibition of HPV oncoprotein. In addition, the further activation of the immune response under the effect of radiation also participates in the elimination of tumors. In this paper, we reviewed the research on the sensitivity of HPV-positive oropharyngeal cancer to radiotherapy to provide a scientific basis for targeted treatment for various pathogenic factors and clinical stages of oropharyngeal cancer in the future.
Bonding of brackets to dental fluorosis has always been a difficult problem for clinicians. At present, clinical research has adopted several methods to facilitate bracket bonding, including prolonging etching time, enamel microabrasion, enamel ground, using adhesion promoter and laser etching. Prolonging etching time is suitable for mild-to-moderate dental fluorosis with easy chair-side operation; however, over-etching may cause severe tooth damage. Microabrasion can be applied to mild dental fluorosis while removing pigment deposition simultaneously; however, rubber dam protection is needed. Enamel ground can improve the bond strength to all kinds of dental fluorosis at the price of removing a relatively large amount of superficial enamel. Adhesion promoters might improve the bond strength of moderate to severe dental fluorosis; however, the current results conflict with one another. This needs further verification using larger-sample clinical trials. Laser etching has no effect on improving bond strength; however, it can remove pigment without destroying tooth enamel, which is worth further modification and enhancement.
This work is licensed under Creative Commons Attribution 4.0 License.
