Intentional replantation for the treatment of a double-rooted maxillary lateral incisor with periodontal-endodontic lesions: a case report and literature review / 口腔疾病防治

Objective@#To investigate the clinical characteristics, diagnosis and treatment of severe combined periodontal-endodontic lesions in a double-rooted maxillary lateral incisor with a palatal radicular groove and to provide a reference for clinical diagnosis and treatment.@*Methods@#A patient with a double-rooted left maxillary lateral incisor with a palatal radicular groove and severe combined periodontal-endodontic lesions underwent complete root canal therapy and intentional replantation, and a retrospective analysis of the management of this type of patient was performed based on the literature.@*Results@#The 3-year follow-up examination revealed no discomfort, good healing of the upper left lateral incisor, no pathological loosening, and a palatal gingival sulcus was found at a depth of approximately 1 mm. Review of the literature showed that the prognosis of the affected tooth and the choice of treatment plan were correlated with the length and depth of extension of the lingual groove toward the root, the periodontal condition and the pulpal status of the affected tooth. For minor PRGs or for affected teeth with no loss of pulpal viability, flap surgery and odontoplasty can be used to avoid endodontic treatment or retreatment. For deep or long lingual grooves that result in significant loss of periodontal tissue, endodontic treatment, odontoplasty, or closure of the grooves and guided tissue regeneration are needed. In the case of PRGs with double root formation, the affected tooth can be preserved via root canal therapy, removal of the small root and filling with apical restorative material, and intentional replantation.@*Conclusion@#In cases of severe combined periodontal-endodontic lesions due to palatal radicular grooves occurring in double-rooted maxillary lateral incisors, clinical presentation and imaging can prevent missed diagnoses, and appropriate treatment should be based on the length and depth of lingual grooves extending toward the roots, periodontal conditions, and pulpal status of the affected teeth.

Effects of atractylodin on inflammatory damage of periodontal tissue and alveolar bone loss in periodontitis rats and its mechanism / 中国药房

OBJECTIVE To investigate the effects and mechanism of atractylodin on inflammatory injury of periodontal tissue and alveolar bone loss in periodontitis rats. METHODS A total of 144 SD rats were divided into control group （intragastric and intraperitoneal injection of normal saline）， model group （intragastric and intraperitoneal injection of normal saline）， atractylodin low-dose， medium-dose and high-dose groups （intraperitoneal injection of 6.665， 13.33， and 26.66 mg/kg atractylodin）， metronidazole group （positive control group， intragastric injection of 0.05 g/kg metronidazole， intraperitoneal injection of normal saline）， AMD3100 [stromal cell-derived factor-1 （SDF-1）/CXC chemokine receptor-4 （CXCR4） pathway inhibitor] group （intragastric injection of 1 mg/kg AMD3100， intraperitoneal injection of normal saline）， atractylodin high-dose+AMD 3100 group （intraperitoneal injection of 26.66 mg/kg atractylodin， intragastric injection of 1 mg/kg AMD3100）， with 18 rats in each group. Except for the control group， all other groups of rats were inoculated with Porphyromonas gingivalis to construct a periodontitis model. After successful modeling， they were given relevant medicine or normal saline， once a day， for 4 consecutive weeks. The gingival index of rats was detected； the levels of interleukin-6 （IL-6） and tumor necrosis factor α （TNF-α） in rat serum were also determined； alveolar bone resorption， periodontal histopathologic changes and the number of osteoclasts were detected by methylene blue staining， HE staining and TRAP staining， respectively. The expressions of osteoprotegerin （OPG）， receptor activator of NF-κB ligand （RANKL）， SDF-1 and CXCR4 proteins were determined. RESULTS Compared with the control group， serious pathological injury of periodontal tissue was found in the model group， the gingival index， the levels of IL-6 and TNF- α， alveolar bone absorption value， the number of osteoclasts， and the expression of RANKL protein were all increased significantly （P＜0.05）， while the expressions of OPG， SDF-1 and CXCR4 proteins were decreased significantly （P＜0.05）. Compared with the model group， pathological injury of periodontal tissue in rats was reduced； the gingival index， the levels of IL-6 and TNF-α， alveolar bone resorption value， osteoclast number and RANKL protein expression were decreased significantly， while protein expressions of OPG， SDF-1 and CXCR4 were increased significantly in atractylodin low-dose， medium-dose and high-dose groups and metronidazole group （P＜0.05）. The change trend of corresponding indexes in the AMD3100 group was opposite to the above （P＜0.05）. AMD3100 attenuated the inhibitory effect of high-dose atractylodin on inflammatory response and alveolar bone loss in rats with periodontitis （P＜0.05）. CONCLUSIONS Atractylodin may improve the inflammatory response and alveolar bone loss in periodontitis rats by activating the SDF-1/CXCR4 signaling pathway.

Research progress of periodontal tissue regeneration by combined biomaterials of dental derived mesenchymal stem cells / 口腔医学

@#The ultimate treatment goal of periodontitis is the structural and functional regeneration of periodontium. However, existing methods for periodontal regeneration have difficulties in regenerating the hierarchical structure. Therefore, stem cell-based tissue engineering has attracted more and more attention for its advantages of self-renewal and multi-lineage differentiation potential. This review summarized the progress of research on periodontal tissue regeneration by combined biomaterials of dental-derived stem cells. It is pointed out that the application of autologous stem cell transplantation is limited by the donor source, and the subsequent research should focus on the development of multi-phase scaffold materials and the attempt to establish a stem cell bank.

Applicatoin of chitosan-based hydrogel in oral tissue engineering / 中南大学学报(医学版)

Pulpitis, periodontitis, jaw bone defect, and temporomandibular joint damage are common oral and maxillofacial diseases in clinic, but traditional treatments are unable to restore the structure and function of the injured tissues. Due to their good biocompatibility, biodegradability, antioxidant effect, anti-inflammatory activity, and broad-spectrum antimicrobial property, chitosan-based hydrogels have shown broad applicable prospects in the field of oral tissue engineering. Quaternization, carboxymethylation, and sulfonation are common chemical modification strategies to improve the physicochemical properties and biological functions of chitosan-based hydrogels, while the construction of hydrogel composite systems via carrying porous microspheres or nanoparticles can achieve local sequential delivery of diverse drugs or bioactive factors, laying a solid foundation for the well-organized regeneration of defective tissues. Chemical cross-linking is commonly employed to fabricate irreversible permanent chitosan gels, and physical cross-linking enables the formation of reversible gel networks. Representing suitable scaffold biomaterials, several chitosan-based hydrogels transplanted with stem cells, growth factors or exosomes have been used in an attempt to regenerate oral soft and hard tissues. Currently, remarkable advances have been made in promoting the regeneration of pulp-dentin complex, cementum-periodontium-alveolar bone complex, jaw bone, and cartilage. However, the clinical translation of chitosan-based hydrogels still encounters multiple challenges. In future, more in vivo clinical exploration under the conditions of oral complex microenvironments should be performed, and the combined application of chitosan-based hydrogels and a variety of bioactive factors, biomaterials, and state-of-the-art biotechnologies can be pursued in order to realize multifaceted complete regeneration of oral tissue.

Research progress on basic fibroblast growth factor in promoting periodontal tissue regeneration / 口腔疾病防治

@#Basic fibroblast growth factor (bFGF) exhibits superior biological functions by improving periodontal inflammation, promoting the migration and proliferation of periodontal-related stem cells, promoting the formation of blood vessels and periodontal ligament-like tissue, and regulating the formation of bone/cementum. It plays an important role in tooth development, repair and regeneration. bFGF can be combined with seed cells and scaffold materials for periodontal tissue regeneration, which has been verified in a number of experimental studies. However, the application of bFGF alone as a drug in clinical treatment requires further research.

Correlation between proteoglycan and alveolar bone resorption in a mouse periodontitis model / 口腔疾病防治

Objective@#To analyze changes in proteoglycan and its correlation with alveolar bone resorption in periodontitis. @*Methods @#Twelve eight-week-old C57BL/6J male mice were selected, and the periodontitis model was established by ligating the right maxillary second molar with 6-0 silk thread. The nonligated part of the left maxilla was used as the control. The mice were killed 14 days after the operation. Micro-CT was used to assess alveolar bone resorption. HE staining was used to observe the alveolar bone profile, and TRAP staining was conducted to examine the positive rate of osteoclasts. The expression of proteoglycan-related genes, such as aggrecan (ACAN), biglycan (BGN), versican (VCAN), decorin (DCN), osteoclast-related genes, such as cathepsin K (CTSK), matrix metalloprotein-9 (MMP-9), and receptor activator of nuclear factor kappa-B ligand (RANKL), and inflammation-related genes, such as interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α), was detected by real-time quantitative PCR. Additionally, the correlation of the expression of proteoglycans with osteoclast-related genes and inflammation-related genes was evaluated by Pearson correlation analysis.@* Results@#The resorption of alveolar bone on the periodontitis side increased. TRAP staining showed that the number of osteoclasts was substantially increased in the maxilla with periodontitis. Real-time quantitative PCR demonstrated that compared with the control side, the expression of proteoglycan-related genes, such as ACAN, BGN, and DCN, was decreased, whereas the expression of the VCAN gene was significantly increased in the periodontitis side. Meanwhile, the expression of osteoclast-related genes, such as CTSK, MMP-9, and RANKL, and inflammation-related genes, such as IL-1β, IL-6, and TNF-α, was markedly increased in the periodontitis side (P<0.05). Pearson correlation analysis indicated a negative correlation between the expression of proteoglycans and the mRNA levels of osteoclast-related genes and inflammation-related genes (P<0.05). @*Conclusion @#The expression of proteoglycan was closely related to alveolar bone resorption in a periodontitis model.

Research progress on microRNA-21 in regulating osteoclast and osteogenic differentiation in orthodontic treatment / 口腔疾病防治

@#In the process of orthodontic treatment, the balance between the modeling of alveolar bone and the mechanical stress exerted by the appliance is key to the effective movement of orthodontic teeth. Alveolar bone modeling involves many regulatory factors, and microRNAs (miRNAs), as posttranscriptional regulatory factors, play an important role in the occurrence of bone modeling. As an important member of the miRNA family, miRNA-21 promotes the differentiation of periodontal ligament stem cells into osteoblasts and plays an important role in maintaining bone balance and preventing bone resorption as a regulator of osteoclast formation and a promoter of osteoclast differentiation. A literature review showed that miRNA-21 can regulate osteoclast function and promote bone resorption through programmed cell death 4 (PDCD4), phosphate and tension homology deleted on chromosome ten (PTEN), receptor activator of nuclear factor-κB ligand (RANKL) and osteoprotegerin (OPG). MiRNA-21 is highly sensitive to external mechanical stress in the process of orthodontic tooth movement. After orthodontic force is applied, miRNA-21 can promote osteoclast formation and accelerate orthodontic movement; through targeted regulation of periodontal ligament associated protein-1 (PLAP-1), it can regulate periodontal ligament remodeling in the late stage of tooth movement and improve the potential of tooth movement. In addition, miRNA-21 mediates orthodontic tooth movement (OTM) and alveolar bone remodeling in the periodontal inflammatory microenvironment. miRNA-21 can upregulate the expression of hypoxia-inducible factor-1α (HIF-1α) in periodontal ligament stem cells in a hypoxic environment. It can promote the expression of osteogenic markers, such as osteopontin (OPN), osteocalcin (OCN), alkaline phosphatase (ALP) and runt-related transcription factor 2 (Runx2), and promote osteogenic differentiation during orthodontic tooth movement.

Effect of miR-21 on the proliferation and osteogenic differentiation of human periodontal ligament stem cells / 口腔疾病防治

Objective @# To explore the effect of miR-21 on human periodontal ligament stem cells (PDLSCs) proliferation and osteogenesis and to provide a theoretical basis for the stem cell treatment of periodontitis.@*Methods@#hPDLSCs were isolated and cultured with the enzymatic tissue block method, and surface molecules (CD34, CD45, CD90 and CD105) were detected by flow cytometry. An miR-21 mimics (pre-miR-21) and inhibitor (anti-miR-21) were transfected into hPDLSCs by Lipofectamine 2000. The experiment groups: mimics-NC group, mimics group, inhibitor group, and inhibitor-NC group. The transfection efficiency of miR-21 was determined by qRT-PCR. Proliferation was detected by CCK-8 and flow cytometry. The osteogenic differentiation ability of hPDLSCs was determined by alizarin red staining. Western blot was used to detect the protein expression of osteogenic related genes: Runx2.@*Results@#The mRNA expression of miR-21in the mimics group was significantly higher than that in the mimics-NC group; additionally, the expression in the inhibitor group was significantly weaker than that in the inhibitor-NC group (P < 0.05). hPDLSCs proliferation and the S phase cell ratio in the mimics group were stronger than those in the mimics-NC group(P < 0.05); those in the inhibitor group were weaker than those in the inhibitor-NC group (P < 0.05). After alizarin red staining, the mimics group was found to have more mineralized modules than mimics-NC group, and the inhibitor group had fewer than that in the inhibitor-NC group. Runx2 protein expression in the mimics group was higher than that in the mimics-NC group (P <0.05), and expression was lower in the inhibitor group than in the inhibitor-NC group (P < 0.05).@*Conclusion@#miR-21can promote the proliferation and osteogenesic differentiation of hPDLSCs.

Research progress on cell sheet technology and its application in periodontal tissue regeneration / 口腔疾病防治

@#At present, conventional periodontal treatment cannot achieve complete and effective periodontal tissue regeneration. Cell sheet technology (CST) is a kind of cell transplantation method without scaffold material that can maintain complete extracellular matrix, important ion channels of cells, growth factor receptors, etc., and ensure the interaction between cells and the extracellular matrix. In this paper, the application and research progress of the cell sheet in the field of periodontal tissue regeneration are reviewed. Different types of seed cells can be prepared into monolayer cell sheet, multilayer cell sheet, cell sheet fragments and cell sheet polymers. Among them, the monalayer cell sheet is easily damaged and requires high deoperator; the multilayer cell sheet shows improved mechanical properties, but its thickness needs to be controlled to avoid cell necrosis. The cell sheet fragment can be used in the narrow space between the alveolar bone and root cementum to reduce the difficulty of operation and improve the mechanical properties of the cell sheet. Cell sheet polymers are three-dimensional structures that can provide strong mechanical support and improve the stability of the cell sheet, but the stability of their biological activity needs to be further improved. In methods for construction of the cell sheet, the antifibrosis and antiangiogenesis properties of the amniotic sheet have shown that this structure is suitable as the matrix of cell culture; the method of using a temperature-sensitive culture dish is simple and easy; continuous induction with vitamin C can retain some important proteins on the cell surface; and the magnetic tissue engineering method can increase cell adhesion and easily form a stable cell sheet. The above methods have their own characteristics. In clinical applications, monolayer cell sheet is mainly used for direct transplantation to the receiving site to construct periodontal tissue; multilayer cell sheet of the same or different species overlap and are then transplanted to the receiving site; and multilayer cell sheet of the same kind are wrapped with scaffold material and then transplanted to the receiving site to construct a three-dimensional structure. Overall, cell sheet technology has shown good potential in periodontal tissue regeneration.

Endodontic-periodontal combined therapy for type Ⅲ dens invaginatus in maxillary lateral incisor: a case report / 华西口腔医学杂志

We report a clinical case of type Ⅲ dens invaginatus with endodontic-periodontal lesion in a maxillary lateral incisor. The palatal radicular anomaly predisposed the tooth to periodontal lesions. The caries along the palatal groove caused tooth pulp necrosis and periapical lesions. By means of microscopic root canal therapy, apical surgery, and guided periodontal tissue regeneration, the apical and periodontal infection were controlled, and the affected tooth was retained.

Effect of recombinant human amelogenin-loaded PCLA-PEG-PCLA hydrogels on biological properties of human periodontal ligament fibroblasts / 上海交通大学学报（医学版）

Objective • To determine the effect of recombinant human amelogenin (rhAm)-loaded PCLA-PEG-PCLA hydrogels on cell proliferation, immigration, attachment and osteogenic differentiation of human periodontal ligament fibroblasts (HPDLFs). Methods • HPDLFs were obtained by tissue block method in vitro from extracted premolars and the 3rd-5th passages of HPDLFs were treated with DMEM medium (control group), 20 μg/mL rhAm (rhAm group) or rhAm-loaded PCLA-PEG-PCLA hydrogels (rhAm-loaded hydrogel group). Proliferation activity was measured by CCK-8, while cell migration was assayed both by wound-healing experiment in vitro and Transwell experiment. Cell attachment was measured by hemocytometer and observed by scanning electron microscope. Osteogenic differentiation was measured by real-time PCR, with ALP, Runx2, CEMP1 and CAP as the target genes. Results • RhAm-loaded PCLA-PEG-PCLA hydrogels had no significant effect on cell growth curve of HPDLFs, but promoted cell proliferation after 3 days (P<0.05). RhAm accelerated cell migration mostly both in wound-healing experiment and Transwell experiment, with rhAm-loaded hydrogels in the second place. RhAm-loaded hydrogels promoted cell attachment, and in the 4th hour the promotion was of statistic significance (P<0.05). Meanwhile cells of rhAm group and rhAm-loaded hydrogel group had a better stretch condition than control group under the scanning electron microscope. After culture with rhAm-loaded hydrogels, ALP, Runx2, CEMP1, and CAP mRNA were upregulated in different time points. Conclusion • Recombinant human amelogenin-loaded PCLA-PEG-PCLA hydrogels can significantly improve proliferation, attachment and osteogenic differentiation of HPDLFs, but has no effect on cell migration on a statistical scale.

Application of 3D printing technology in preparation of scaffolds for periodontal tissue regeneration / 口腔疾病防治

@#How to obtain ideal regeneration of periodontal tissue remains a challenge in the clinical treatment of periodontitis. Three-dimensional printing technology is based on computer-aided design, which produces materials with specific 3D shapes by layer-by-layer superposition, and has been applied to periodontal tissue regeneration therapy, this method offers hope to achieve ideal periodontal regeneration. This article reviews the application of 3D printing technology in the field of periodontal tissue regeneration. The literature review results show that 3D printing technology can design three-dimensional structures using computer software in advance and produce materials with specific three-dimensional structures. 3D printing technology mainly includes selective laser sintering, selective laser melting, extrusion forming printing and 3D bioprinting. At present, the support materials prepared by 3D printing technology include ceramic materials, polymer materials and metals. Submaterials have been extensively studied given their high adjustability, and 3D-printed personalized titanium mesh has been applied in the clinic. Multiphase materials prepared by 3D-printing technology can regenerate periodontal tissue in animal experiments, but the effect is not good in patients with periodontitis. In addition, 3D printing of composite scaffolds for periodontal tissue regeneration need to be further studied.

Research progress on the common risk factors and related mechanisms of periodontitis and osteoporosis / 口腔疾病防治

@#Periodontitis is a chronic infectious disease of periodontal tissue caused by plaque biofilm. Osteoporosis is a systemic skeletal disease characterized by low bone density and the microarchitectural deterioration of bone tissues, which leads to increased bone fragility and risk of fracture. Recent studies have indicated that there is a certain relationship between periodontitis and osteoporosis. This paper reviews the epidemiology, shared risk factors, and potential mechanisms of mutual impact between the two diseases. A literature review shows that periodontitis and osteoporosis can affect each other, and the RANKL-RANK-OPG pathway as well as a variety of cytokines and hormones involved in bone remodeling and inflammation are involved in both diseases. Common risk factors for periodontitis and osteoporosis include aging, vitamin D and calcium deficiency, and smoking, but further research is needed to determine the specific mechanism of interaction between periodontitis and osteoporosis.

Progress relationship between periostin and periodontitis / 华西口腔医学杂志

Periostin, a kind of matricellular protein highly expressed in periodontal ligament and periosteum, is an important regulator of the integrity of periodontal ligament and periodontitis processes. Periostin has been shown to play a positive role in the recovery of periodontitis. This paper reviews relevant literature about the role of periostin in periodontal tissue and periodontitis.

Application effect of glass fiber pile and cast metal pile in tooth defect repair and its influence on periodontal tissue / 中国基层医药

Objective To analyze the application effect of glass fiber pile and cast metal pile in tooth defect repair and its influence on periodontal tissue.Methods From February 2014 to February 2015,112 patients with dental defect in the Central Hospital of Yiwu were randomly divided into the control group and the research group according to the digital table,with 56 cases in each group.The control group received the casting metal pile repair,the research group was repaired with glass fiber piles.The remediation effect,periodontal tissue status,inflammatory response and adverse reaction were compared between the two groups.Results The success rate of the research group was significantly higher than that of the control group(89.29％vs.66.07％),and there was statistically significant difference(χ2 =8.70,P<0.05).After treatment,the alkaline phosphatase,interleukin-6(IL-6)and interleukin-8(IL-8)levels of the two groups were increased compared with before treatment,which of the research group were obviously lower than those of the control group [(440.75 ±55.75)U/L vs.(491.75 ±62.59)U/L,(18.77 ± 2.21)ng/L vs.(30.65 ±3.97)ng/L,(51.42 ±6.32)μg/L vs.(76.33 ±9.50)μg/L],there were statistically significant differences(t=4.52,19.56,16.33,all P<0.05).After treatment,the periodontal examination depth of the two groups was(2.15 ±0.29)mm and(2.17 ±0.25)mm,respectively,and there was no statistically significant difference(t=0.39,P>0.05).Conclusion The effect of glass fiber pile in tooth defect repair is better than cast metal pile,and its stability and biocompatibility are better,and it is a simple operation,which is worthy of clinical promotion.

Effects of bacterial lipopolysaccharide on the mineralization and differentiation of periodontal ligament stem cells / 医学研究生学报

Objective Periodontal tissue engineering has shown a highlight prospect in the treatment of periodontitis,but the related clinical experiments have not achieved the predetermined goal. In this study,we analyzed the reasons for the limited clinical efficacy of periodontal tissue engineering. Methods We primarily cultured the periodontal tissue from the young permanent teeth extracted for or-thodontic treatment,isolated periodontal ligament stem cells (PDLSCs),and transplanted the well-grown third-generation PDLSCs onto the fluorapatite-polycaprolactone (FA-PCL) nanofiber scaffolds and PCL nanofiber scaffolds. We randomly divided the cells into groups A (cultured with 10 ng/mL porphyromonas gingivalis lipopo-lysaccharide (Pg-LPS)+FA-PCL),B (cultured with 10 ng/mL PG-LPS+PCL),C (cultured with 10 μg/mL PG-LPS+FA-PCL),D (cultured with 10 μg/mL PG-LPS+PCL),E (cultured with FA-PCL),and F (cultured with PCL),and observed their proliferation,differentiation and mineralization. Results The PDLSCs adhered and grew well after transplanted onto the nanofiber scaffolds and their proliferation significantly increased in groups A and B but decreased in C and D as compared with E and F. At 7 days,the expres-sions of ALP and mineralization-related genes runx2 and SPP1 in the PDLSCs were significantly higher in group E than in the other five groups (P<0.05),but higher groups A and C than in B and D as well as in A than in C. At 28 days,alizarin red and Von Kossa stai-ning showed a higher positivity in group E than in the other five groups,but higher groups A and C than in B and D as well as in A than in C. Conclusion The inflammatory environment not only affects the proliferation of PDLSCs,but also inhibits their differentiation and mineralization. The FA-PCL scaffold can reduce the cytotoxic effect of PG-LPS.

Periodontal status assessment before orthodontic treatment and opportune moment selection for orthodontic treatment / 华西口腔医学杂志

The aesthetic demands of teeth by the public have improved with the increase in the living standard. Orthodontics, which is a method of aesthetic dentistry, is becoming increasingly important. Orthodontic treatment mainly involves the application of orthodontic force to the teeth and guides the reconstruction of the periodontal tissue, thereby changing the position of the teeth at the occlusal bone. Orthodontic treatment can also improve the dental occlusion caused by dentition crowding and teeth mobility to achieve long-term stability of periodontal tissue. The number of patients with periodontal disease is high in China, and the number of patients with periodontal disease that are eager to receive orthodontic treatment is increasing. Hence, the periodontal status during the orthodontic therapy should be explored along with periodontal therapy and orthodontic treatment. This article briefly demonstrates the assessment criteria of periodontal status before orthodontic treatment, the opportune moment selection for orthodontic treatment, and the supportive periodontal therapy. This study helps dentists develop individualized treatment programs and win a balanced, stable, and aesthetic impression.

Correlation between mother's behavior with periodontal status and periodontal treatment needs in children with autism

Background@#Autism is a neurological and developmental disorder. Children with autism have problems related to physical, psychological, and mental barriers that can hinder their ability to achieve optimal dental health status. Maintaining the dental health of children with autism is influenced by parents' teaching skills and habits. From previous study, there were about 17.4% children with autism in Saudi Arabia suffering from bleeding of the gingiva. Periodontal disease is often found in children with autism.@*Objective@#This study analyzes the relationship between mother’s behavior with periodontal status and periodontal treatment needs of children with autism.@*Methods@#Analytical observational study with cross-sectional approach at AGCA Centre Surabaya with a total sample of 34 pairs of children with autism and their mothers. This study used the HU-DBI questionnaire which consisted of knowledge, attitude, and mother’s action and oral examination of children with autism with the CPITN index.@*Results@#Of the children with autism, 55.8% had healthy periodontal status. The knowledge, attitudes, and actions of mothers were high. Statistical results with Spearmen correlation test obtained a value of p>0.05 on aspects of knowledge, attitudes, and actions towards the CPITN index and periodontal treatment needs.@*Conclusion@#There was no significant correlation between the mother’s behavior and the periodontal status and periodontal treatment needs of children with autism in managing their oral health.

The Effect of Apical Resection on Biomechanical Properties of Maxillary Central Incisor by Three- / 医用生物力学

Objective To study the tooth and periodontal stress distribution and tooth displacement after apical root resection, so as to provide data support for clinicians to perform apical root surgery and improve the cure rate of apical root surgery. Methods Three-dimensional (3D) finite element model of normal maxillary central incisor with its periodontal tissues was established based on Micro CT image data. Then periapical periodontitis and apical root resection surgery were simulated. The model of periapical periodontitis and maxillary central incisor with different apical root resection length (3, 4, 5, 6, 7, 8 mm) and their supporting tissues were established. With the occlusal force applied, the biomechanical behavior of postoperative healing teeth was studied by 3D finite element analysis. The optimal apical resection length was obtained by comparing biomechanical effects of surgical restoration. Results The completely healed model reduced the stress (by 26.8%) and displacement (by 7.3%) compared with the apical periodontitis model. With the increase of apical root resection length, the stress of the teeth neck and periodontal ligament increased by 11.14% and 29.27%, respectively, when the root resection was 8 mm. The stress of the alveolar bone increased by 83.11%. The stress of new apical root at the section increased on the whole compared with the same part of normal tooth. The displacement of the tooth along the long axis also increased. The displacement significantly increased by 18.39% when the resection length was over 5 mm. Conclusions Apical root resection significantly improves the biomechanical properties of refractory apical periodontitis tooth. The recommended resection length was 3-5 mm and the crown-to-root ratio (CRR) should be larger than 0.84.

Expression of hypoxia-inducible factor 1α in the pressure-side periodontium during orthodontic tooth movement in rats / 口腔疾病防治

Objective @#To assess hypoxia-inducible factor 1α (HIF-1α) expression levels in the periodontal tissues of the pressure side during orthodontic tooth movement in rats.@*Methods@#A total of 50 male 6-week-old Sprague Dawley (SD) rats were randomly divided into 10 groups of 5 rats each. The upper left first molar was the experimental tooth and was pulled mesially with an orthodontic force of 10-15 g for 0, 1, 3, 6, or 12 h, or 1, 3, 7, 14, or 21 d. Routine five-micrometer paraffin-embedded tissue sections were processed for HE staining and immunohistochemical staining for HIF-1α. The Image-Pro Plus system was used to quantitatively analyze the stained slices. The expression of HIF-1α in the periodontal tissue of the pressure side changed during the process of orthodontic tooth movement.@*Results@#The expression of HIF-1α increased immediately after loading for 1 h, reached a small peak at 3 h, and then decreased. After 12 h, the expression increased again, reached a peak after 1 d, and then gradually decreased to near the pre-loading level(P < 0.05). @*Conclusion@#There were differences in expression of HIF-1α in different groups in the periodontal tissues of the pressure side during orthodontic tooth movement in rats.