Diagnosis and antidiastole of leukemia-associated gingival lesions / 中华口腔医学杂志

Leukemia is a heterogeneous group of hematological disorders that arises from a hematopoietic stem cell characterized by a disordered differentiation and proliferation of neoplastic cells. The prevalence of leukemia is high in juveniles and adults under 35 years. Gingival manifestations of leukemia include gingiva bleeding, enlargement, pallor, petechial, ulceration, which may be the first clinical signs of leukemia. In the dental clinic, identification of leukemia-associated gingival lesions, referring patients to hematologists without delay will improve the prognosis of leukemia. Diagnosis and antidiastole of leukemia-associated gingival lesions have been discussed with reference to the related cases.

Exploration and practice of Peking University Model to improve the clinical teaching effect of clinical postgraduates majoring in periodontology / 中华口腔医学杂志

The number of patients with periodontal disease in China is large, and the ratio of doctors to patients is seriously imbalanced, especially in the insufficient number of periodontal specialists and periodontal teachers. Strengthening the cultivation of professional postgraduates in periodontology can effectively solve this problem. This paper summarizes the experiences of Peking University School and Hospital of Stomatology in the teaching of periodontal postgraduate students for more than 30 years, in cluding teaching objectives formulation, teaching resources allocation and enhancement of the quality control system of clinical teaching, for ensuring that the periodontal professional postgraduates could reach the expected level after training. This formed the current "Peking University Model". There are both opportunities and challenges in clinical teaching of periodontal postgraduates in domestic stomatology community. The authors hope that the continuous exploration and improvement of this teaching system will promote the vigorous development of clinical teaching for the postgraduates majoring in periodontology in China.

Comparison of initial periodontal therapy and its correlation with white blood cell level in periodontitis patients with or without diabetes mellitus / 北京大学学报(医学版)

OBJECTIVE@#To compare the clinical efficacy of initial periodontal therapy in periodontitis patients with or without type 2 diabetes mellitus and its correlation with white blood cell counts.@*METHODS@#In this study, 32 chronic periodontitis patients without systemic disease (CP group) and 27 chronic periodontitis patients with type 2 diabetes mellitus (CP+DM group) were enrolled. At admission, all the patients went through periodontal examination and fasting blood examination(baseline). Probing depth (PD), attachment loss (AL), bleeding index (BI), plaque index (PLI), white blood cells (WBC) counts and fasting blood glucose (FBG) were recorded respectively, while hemoglobin A1c (HbA1c) was recorded only in CP+DM group. After that, initial periodontal therapy was performed. All the tests were repeated 3 and 6 months after treatment. The changes of periodontal clinical indexes and WBC levels were compared between the two groups before and after treatment, and the correlation between WBC and periodontal clinical indexes and glucose metabolism indexes were analyzed by generalized linear mixed model.@*RESULTS@#At baseline, the periodontal inflammation and destruction were similar in CP and CP+DM group, but the WBC level was significantly higher in CP+DM groups [(6.01±1.26)×109/L vs. (7.14±1.99)×109/L, P=0.01]. After 3 and 6 months of initial periodontal therapy, the mean PD, AL, BI, and PLI in CP+DM and CP groups were significantly lower than the baseline, and the PD in CP+DM group was further decreased by 6 months compared with 3 months [(3.33±0.62) mm vs. (3.61±0.60) mm, P < 0.05]. However, none of these periodontal indexes showed significant difference between the two groups by 3 or 6 months. In CP+DM group, HbA1c at 3 months and 6 months were significantly lower than the baseline [(7.09±0.79)% vs. (7.64±1.16)%, P < 0.05; (7.06±0.78)% vs. (7.64±1.16)%, P < 0.05], and FBG was significantly lower than the baseline by 6 months [(7.35±1.14) mmol/L vs. (8.40±1.43) mmol/L, P < 0.05]. The WBC level in CP group was significantly lower than the baseline level by 3 months [(5.35±1.37)×109/L vs. (6.01±1.26)×109/L, P < 0.05], while that in CP+DM group was significantly lower than the baseline level by 6 months [(6.00±1.37)×109/L vs. (7.14±1.99)×109/L, P < 0.05]. The analysis of genera-lized linear mixed model showed that WBC level was significantly positively correlated with PD and FBG (P < 0.05).@*CONCLUSION@#Initial periodontal therapy can effectively improve the periodontal clinical status of patients with or without type 2 diabetes mellitus, and have benefits on glycemic control in diabetic patients. However, the response of periodontal indexes and WBC level to initial therapy were relatively delayed in diabetic patients. WBC plays an important role in the correlation between diabetes mellitus and periodontitis.

Gene polymorphisms of cytochrome B-245 alpha chain (CYBA) and cholesteryl ester transfer protein (CETP) and susceptibility to generalized aggressive periodontitis / 北京大学学报(医学版)

OBJECTIVE@#To explore the correlation of cytochrome B-245 alpha chain (CYBA) rs4673 and cholesteryl ester transfer protein (CETP) rs12720922 polymorphisms with the susceptibility of gene-ralized aggressive periodontitis (GAgP).@*METHODS@#The study was a case-control trial. A total of 372 GAgP patients and 133 periodontally healthy controls were recruited. The CYBA rs4673 and CETP rs12720922 polymorphisms were detected by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Logistic regression models were used to analyze the correlation of CYBA rs4673 and CETP rs12720922 variants with the susceptibility of GAgP. The interaction between the two gene polymorphisms to the susceptibility of GAgP was analyzed by the likelihood ratio test. The interaction model adopted was the multiplication model.@*RESULTS@#The mean age of GAgP group and control group was (27.5±5.2) years and (28.8±7.1) years respectively. There was significant difference in age between the two groups (P < 0.05). The gender distribution (male/female) was 152/220 and 53/80 respectively, and there was no significant difference between GAgP group and controls (P>0.05). For CYBA rs4673, the frequency of CT/TT genotype in the GAgP group was significantly higher than that in the controls [18.0% (66/366) vs. 10.6% (14/132), P < 0.05]. After adjusting age and gender, the individuals with CT/TT genotype had a higher risk of GAgP (OR=1.86, 95%CI: 1.01-3.45, P < 0.05), compared with CC genotype. There was no statistically significant difference in distributions of the CETP rs12720922 genotypes (GG, AA/AG) between GAgP patients and healthy controls (P>0.05). A significant interaction between CYBA rs4673 and CETP rs12720922 in the susceptibility to GAgP was observed. The GAgP risk of the individuals with CYBA rs4673 CT/TT and CETP rs12720922 GG genotypes was significantly increased (OR=3.25, 95%CI: 1.36-7.75, P < 0.01), compared with those carrying CC and AA/AG genotypes.@*CONCLUSION@#CYBA rs4673 CT/TT genotype is associated with GAgP susceptibility. There is a significant interaction between CYBA rs4673 CT/TT genotype and CETP rs12720922 GG genotype in the susceptibility of GAgP.

Expression and distribution of calprotectin in healthy and inflamed periodontal tissues / 北京大学学报(医学版)

OBJECTIVE@#Calprotectin, the heterdimer of S100A8 and S100A9, is the major cytoplasmic protein of neutrophils, which is also expressed or induced in gingival epithelial cells, activated mononuclear macrophages and vascular endothelial cells. Calprotectin is intimately associated with the initiation and progression of periodontitis, but the in vivo expression patterns of calprotectin in healthy and inflamed periodontal tissue are not fully understood. To observe the expression, distribution and cellular localization of calprotectin in the samples of healthy periodontal tissues and experimental periodontitis tissues of Beagles and to explore their relationship with periodontal inflammation and possible effect.@*METHODS@#Experimental periodontitis model was established by ligation around the mandibular second molar of the Beagle dogs, while the contralateral teeth were healthy controls. Induction duration was 12 weeks, before the dogs were executed. Tissue specimens were demineralized and serial sections were made conventionally. The in vivo expression of calprotectin in the healthy and inflamed periodontal tissues were examined by immunohistochemistry. The in vitro expression of calprotectin in human primary gingival fibroblasts (GFs) and periodontal ligament (PDL) cells were detected by immunocytochemistry.@*RESULTS@#Immunohistochemistry analysis indicated that calprotectin was expressed in gingival epithelial cells and infiltrated neutrophils in the healthy periodontium within the gingival epithelium, S100A8/A9 was most strongly expressed in the junctional epithelium, followed by surface epithelium, and least expressed in the sulcular epithelium. The S100A8/A9 expression levels were sharply defined at the junction between the junctional epithelium and the sulcular epithelium. In periodontal inflammatory lesions, the expression level of calprotectin in sulcular epithelium and junctional epithelium was up-regulated than that in the healthy gingival epithelium. Calprotectin was inducibly expressed in fibroblast-like cells in gingival connective tissue and periodontal ligament tissue, microvascular endothelial cells (ECs) and bone marrow fibroblasts under inflammatory conditions. Additionally, the expression of calprotectin in primary human GFs and PDL cells was confirmed by immunnocytochemistry staining.@*CONCLUSION@#Constitutively expressed in neutrophils and gingival epithelial cells, and calprotectin might maintain the homeostasis and integrity of periodontium. Inflammation-induced expression of calprotectin in GFs, PDL cells, microvascular ECs and bone marrow fibroblasts might process anti-microbial function and promote leukocytes transmigration to defend the host against the microorganisms.

Association between root abnormalities and related pathogenic genes in patients with generalized aggressive periodontitis / 北京大学学报(医学版)

OBJECTIVE@#To explore the association between the abnormal root morphology and bone metabolism or root development related gene polymorphism in patients with generalized aggressive periodontitis.@*METHODS@#In the study, 179 patients with generalized aggressive periodontitis were enrolled, with an average age of (27.23±5.19) years, male / female = 67/112. The average number of teeth remaining in the mouth was (26.80±1.84). Thirteen single nucleotide polymorphisms (SNPs) of nine genes which related to bone metabolism and root development were detected by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Root abnormalities were identified using periapical radiographs. The abnormal root morphology included cone-rooted teeth, slender-root teeth, short-rooted teeth, curved-rooted teeth, syncretic-rooted molars, and molar root abnormalities. The number of teeth and incidence of abnormal root morphology in different genotypes of 13 SNPs were analyzed.@*RESULTS@#The constituent ratio of root with root abnormality in GAgP patients was 14.49%(695/4 798). The average number of teeth with abnormal root morphology in GAgP was (3.88±3.84). The average number of teeth with abnormal root morphology in CC, CT and TT genotypes in vitamin D receptor (VDR) rs2228570 was (4.66±4.10), (3.71±3.93) and (2.68±2.68). There was significant difference between TT genotype and CC genotype (t = 2.62, P =0.01). The average number of root morphological abnormalities in CC, CT and TT genotypes of Calcitotin Receptor (CTR) gene rs2283002 was (5.02±3.70), (3.43±3.95), and (3.05±3.12). The incidence of root morphological abnormalities in CC genotype was higher than that in the patients with CT and TT, and the difference was statistically significant(87.86% vs. 65.26% & 63.64%, P=0.006, adjusted OR =3.71, 95%CI: 1.45-9.50). There was no significant difference in the incidence of abnormal root morphology between CT and TT genotypes.@*CONCLUSION@#VDR rs2228570 and CTR rs2283002 may be associated with the occurrence of abnormal root morphology in patients with generalized aggressive periodontitis, which is worthy of further research.

Effect of initial periodontal therapy on blood parameters related to erythrocyte and platelet in patients with type 2 diabetes mellitus and chronic periodontitis / 北京大学学报(医学版)

OBJECTIVE@#To compare the blood parameters related to erythrocyte and platelet between baseline and 3 months after initial periodontal therapy in patients with both type 2 diabetes mellitus and chronic periodontitis (DM-P).@*METHODS@#According to the International Symposium on Classification of Periodontal Diseases and Conditions in 1999 and the diagnostic criteria of type 2 diabetes mellitus proposed by the World Health Organization in 1999, 35 patients with DM-P were recruited. All the participants received initial periodontal therapy, including oral hygiene instruction, scaling, and root planning provided by one senior periodontist. Original diet, exercise, and medication for blood glucose control were unchanged for all the participants. At baseline and 3 months after initial periodontal therapy, the clinical periodontal parameters, including probing depth (PD), bleeding index (BI) and clinical attachment loss (CAL); erythrocyte-related indexes, including red blood cell (RBC) count, hemoglobin (HGB), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), RBC volume distribution width (RDW); platelet-related indexes, including platelet (PLT) count, mean platelet volume (MPV), platelet distribution width (PDW), plateletocrit (PCT) were measured and compared.@*RESULTS@#Compared with baseline, the periodontal parameters, including PD [(3.370±0.601) mm vs. (2.729±0.431) mm], BI [2.160 (1.550~3.410) vs. 1.420 (1.000~2.970)] and CAL [(3.307±1.577) mm vs. (2.990±1.587) mm], were significantly reduced (P < 0.001) three months after the initial periodontal therapy; the erythrocyte-related indexes, including RBC count [(4.727±0.392)×1012/L vs. (4.825±0.394)×1012/L, P=0.010], HGB [(145.886±11.792) g/L vs. (149.200±12.979) g/L, P=0.007] and HCT [43.40% (37.50%~48.50%) vs. 43.80% (38.50%~53.20%), P=0.003], were significantly increased three months after the initial periodontal therapy; PLT count [(216.714±61.900)×109/L vs. (205.886±62.051)×109/L, P=0.016] was significantly reduced 3 months after the initial periodontal therapy.@*CONCLUSIONS@#The initial periodontal therapy can significantly improve blood parameters related to RBC and PLT, which might decrease the risk of vascular complications in DM-P patients.

Influence of local anesthesia on the outcomes of non-surgical periodontal treatment / 中华医学杂志(英文版)

BACKGROUND@#There is limited evidence of the effects of local anesthesia (LA) on outcomes of non-surgical periodontal treatment (NSPT), in particular among the Chinese. This retrospective cohort study aimed to evaluate the effects of LA on short-term treatment outcomes of NSPT and to determine under what circumstances LA should be prescribed to improve these outcomes.@*METHODS@#Data from periodontal examinations of 3980 patients were used. The data were from 3-month re-evaluation records of an electronic periodontal charting record system in the Department of Periodontology of Peking University School and Hospital of Stomatology from June 2008 to January 2015. Descriptive analyses included changes in probing depth (PD) and the Mazza bleeding index (BI). Two-level (patient and tooth) logistic regression models and three-level (patient, tooth, and site) linear regression models were constructed to analyze the influence of LA on PD for all teeth/sites and teeth/sites with an initial PD ≥ 5 mm. Decreases in PD and BI at sites under LA using the initial PD were also compared.@*RESULTS@#A significantly higher mean decrease in PD after NSPT was found in the LA group than in the no local anesthesia (NLA) group (0.98 vs. 0.54 mm, t = 24.12, P  1 and BI > 2) for all teeth (16.7% vs. 13.8%, t = 3.75, P < 0.001; 34.7% vs. 28.1%, t = 6.73, P < 0.001) and PD for teeth with PD ≥ 5 mm (32.3% vs. 17.3%, t = 28.48, P < 0.001). The difference in PD between the LA and NLA groups increased as the initial PD increased. The difference between the two groups was 0.12 to 0.22 mm for sites with a baseline PD < 7 mm; however, it increased to 0.41 to 1.37 mm for sites with a baseline PD ≥ 7 mm.@*CONCLUSIONS@#LA improved the decrease in PD after NSPT. Root debridement at sites with initial PD ≥ 7 mm should be performed under routine LA.

Effect of vertical soft tissue thickness on clinical manifestation of peri-implant tissue in patients with periodontitis / 北京大学学报(医学版)

OBJECTIVE@#To observe and investigate the effect of vertical soft tissue thickness on the peri-implant tissue condition and the prevalence of peri-implant disease in patients with history of periodontitis.@*METHODS@#Among 210 patients who showed initial interest of implant therapy, 92 patients were included in this study and received implant surgery during 2010 and 2015. Sixty-six patients with 66 implants finally came back for T2 evaluation. Prior to the implant therapy, all the patients had received periodontal treatment. During the implant placement surgery, the distance from palatal soft tissue edge to the alveolar crest, which was defined as vertical soft tissue thickness (VT), was measured after the buccal full thickness flap was elevated. According to the cut off point which was adopted from the operating characteristic curve, 66 implants within 66 patients were divided into two groups, which were called normal group (VT≤4.5 mm) and thick group (VT>4.5 mm), respectively. Information of the patient's general status, periodontal situation and implant information were recorded. After a follow-up period of 42.9 months, the parameters of peri-implant tissue and condition of peri-implant disease were recorded. Mann-Whitney U test as well as Chi-square test were used to compare the parameters between two groups. Moreover, Kaplan-Meier method was chosen to draw the event(peri-implantitis)-free survival curve.@*RESULTS@#The survival rate of the implants was 100%. At the end of the follow-up examination(T2), the parameters including max PDi, mean PDi, max BIi, mean BIi, mean MBL, MBL at distal side, MBL at mesial side, mean PLIi presented significantly higher values in thick group than in normal group (P < 0.05). Moreover, the prevalence of peri-implantitis and peri-implant disease (peri-implant mucositis & peri-implantitis) in thick group was respectively 34.8% and 73.9%, which was significantly higher than 2.3% and 48.8% respectively in normal group (P<0.05). The prevalence of peri-implant mucositis did not show significant difference in the two groups. In addition, Kaplan-Meier analysis showed that there was significant difference between the event-free survivals of the two groups.@*CONCLUSION@#The vertical soft tissue thickness around implants in patients with periodontitis has a significant effect on the health of the peri-implant tissue. Excessive vertical soft tissue thickness may result in deeper peri-implant probing depth as well as more peri-implant marginal bone loss, and eventually increase the risk of peri-implant disease. The vertical remodeling of soft tissue may be a new direction to indicate the role of periodontitis in peri-implant tissue condition. Moreover, the biological mechanism of the association between soft tissue thickness and peri-implantitis risk as well as effective approaches to prevent the adverse effect of excessive soft tissue thickness on peri-implant tissue is necessary to be investigated.

Short-term outcome of regenerative surgery treating peri-implantitis / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the short-term outcome of regenerative surgery for peri-implantitis therapy.@*METHODS@#From March 2018 to January 2019, 9 patients with 10 implants who suffered from peri-implantitis were included in the present research. Vertical bone defect at least 3mm in depth with 2 or more residual bone walls was confirmed around each implant by radiographic examination. Restorations were replaced by healing abutments on 3 implants with the consent of the patients. Guided bone regeneration surgery was performed after a hygienic phase. During surgery, full thickness flaps were elevated on both buccal and lingual aspects. Titanium curette was used for inflammatory granulation tissue removal and implant surface cleaning. The implant surface was decontaminated by chemical rinsing with 3% hydrogen peroxide solution. After being thoroughly rinsed with saline, the bone substitutes were placed in bone defects which were covered by collagen membranes. 6 months after non-submerged healing, the clinical parameters including peri-implant probing depth (PD, distance between pocket bottom and peri-implant soft tissue margin) and radiographic bone level (BL, distance form implant shoulder to the first bone-to-implant contact) were used to evaluate the regenerative outcome. PD was measured at six sites (mesial, middle and distal sites at both buccal and lingual aspects) around each implant, and BL was measured at the mesial and distal surfaces of each implant on a periapical radiograph.@*RESULTS@#The deepest PD and largest BL of each implant ranged from 6-10 mm and 3.2-8.3 mm respectively. All the implants healed uneventfully after surgery. The mean peri-implant PD at baseline and 6 months after surgery were (6.2±1.4) mm and (3.1±0.6) mm respectively, and a mean (3.0±1.5) mm radiographic bone gain was observed, P<0.01. Treatment success was defined as: no sites with residual PD≥6 mm, no bleeding on probing, and BL elevation of at least 1 mm. Nine implants from 8 patients fulfilled the success criteria. Residual pockets with 6 mm in depth and bleeding on probing could be detected in only one implant.@*CONCLUSION@#Within the limitation of the present research, guided bone regeneration surgery can be used for the treatment of bone defect that resulted from peri-implantitis. Significant PD reduction and radiographic bone gain can be obtained after 6 months observation.

Tooth loss and multivariable analysis after 5-year non-surgical periodontal treatment on molars with furcation involvement / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the tooth loss status of mandibular molars with furcation involvements after 5-year non-surgical periodontal treatment, and to analyze the factors that affected the tooth loss.@*METHODS@#A retrospective analysis was conducted in 79 patients with chronic periodontitis, who had received non-surgical periodontal treatment and 5 years of periodontal maintenance treatment in Department of Periodontology, Peking University School and Hospital of Stomatology from 1988 to 2012. Their clinical indexes, including probing depth (PD), bleeding index (BI), furcation index (FI) and tooth mobility were both evaluated before treatment and at the last time of the maintenance treatment. Bone resorption at furcation area was measured at the first visit by periapical radiographs taken by professional doctors of medical imaging. The status of tooth loss after 5-year non-surgical periodontal treatment on mandibular molars with furcation involvement, and the factors that affected the tooth loss were analyzed.@*RESULTS@#(1) Non-surgical treatment was significantly effective on the changes of PD in the patients of chronic periodontitis with furcation involvement, while the presence of furcation involvement could affect the improvement of PD here. (2) PD at the furcation area, tooth mobility, vertical bone resorption, and bone resorption area were all significant risk factors of mandibular molar missing (P<0.001), and the same with FI=3 and FI=4 (P=0.017, P=0.007), while age (P=0.703), gender (P=0.243) and smoking history (P=0.895) were not related to the tooth loss in this study. (3) The risk of tooth loss in mandibular molars with FI≥3 were significantly higher than those with FI≤2, and the survival rate of the former was less than 50%.@*CONCLUSION@#The loss of mandibular molars with furcation involvement was related to the furcation involvement, meanwhile the degree of furcation involvement and bone resorption can significantly increase the risk of tooth loss.

Clinical study of locking-taper implants in patients treated for periodontitis / 北京大学学报(医学版)

OBJECTIVE@#To evaluate the survival rate and peri-implant clinical parameters of Locking-Taper implants in patients having lost their teeth due to non-periodontitis (NP) reasons, chronic periodontitis (CP) and aggressive periodontitis (AgP).@*METHODS@#In the study, 145 subjects were installed with 315 Bicon Locking-Taper implants and followed up for 1-5 years. The subjects and implants were classified into three groups, tooth loss by NP, CP and AgP. NP included 44 subjects with 100 implants, CP 70 subjects with 132 implants and AgP 31 subjects with 83 implants. Periodontal parameters before subgingival scaling and root planning (T0), at the end of active periodontal therapy (T1) and at the time of last recall (T2) were recorded. Right after the installation of final restoration and at the time of last recall (T2), peri-implant probing parameters were recorded.@*RESULTS@#After active periodontal therapy, mean probing depth (PD) in CP and AgP were reduced from 4.05 mm, 5.20 mm at T0 to 3.07 mm, 2.96 mm at T1 (P<0.001, P<0.001), (PD≥6 mm)% were reduced from 33.2%, 58.5% at T0 to 14.4%, 10.5% at T1 (P<0.001, P<0.001). The periodontal parameters remained stable at T2 compared with T1 (P>0.05). Cumulative survival rates of implants in NP, CP and AgP were 100%, 97.6% and 100% for 1-5 years' follow-ups with no statistical significance found. At T2, mean implant PD was 2.78 mm, 2.96 mm and 2.97 mm in NP, CP and AgP, with NP significantly lower than the other two groups (P=0.006, P=0.01). The percentage of implant sites with PD≥6 mm was 3.7% in CP and 4.8% in AgP, both significantly higher than NP (P=0.003, P<0.001). 8.4% implant sites showed at least 2 mm deeper than those at prosthesis installation were found in CP group, significantly higher than NP (4.3%, P=0.003).@*CONCLUSION@#Periodontal conditions of patients having lost their teeth for chronic and aggressive periodontitis were significantly improved after active periodontal therapy and remained stable during 1-5 years. Short-term survival rates of Locking-Taper implants in patients treated for CP and AgP was no less than those who lost their teeth for non-periodontitis reasons. More sites with increasing peri-implant probing depth were found in CP and AgP patients, compared with NP.

Evaluation of using cone beam computed tomography as a regular test before and after periodontal regenerative surgery / 北京大学学报(医学版)

OBJECTIVE@#To test the accuracy and credibility of cone-beam computed tomography (CBCT) on measuring the height and volume of alveolar bone defects before periodontal regeneration surgery. By comparing the bone density measured by CBCT before and after the operation, the time to evaluate the efficacy of the periodontal regenerative surgery would be determined.@*METHODS@#Periodontal regenerative surgeries were performed on three-wall bone defects of ten teeth in nine patients. The height of bone defects was measured using both periapical film of distant parallel technique and CBCT before periodontal regenerative surgery. Before the surgery, CBCT data were used to measure the volume of the bone defects and the bone density around the defective areas. The height of the bone defects was measured during periodontal regeneration surgery, and the volume of the defective areas was obtained with bone wax in operation. CBCT was taken 6, 12 and 24 weeks after surgery to measure the bone density in the regenerated region.@*RESULTS@#The Wilcoxon test showed that the height of the bone defects measured preoperatively using periapical film was (0.822±0.222) mm deeper than the intraoperative measurement results, and the difference was statistically significant (P<0.05). Whereas CBCT measurement results was (0.150±0.171) mm less than the intraoperative measurement results, without statistical significant (P>0.05). The regression analysis and the Bland-Altman method also showed that the results of CBCT measurement were more accurate. The Wilcoxon test showed that the bone defect volume measured by CBCT preoperatively was accurate, and the difference between the preoperative and the intraoperative measurements was not statistically significant, ranging from 0.38 to 2.83 mm3 (P>0.05). The bone density of the regenerated areas measured by CBCT was (0.49±0.03) times in the sixth week, (0.74±0.09) times in the twelfth week and (1.16±0.11) times in the twentieth week as that of the areas around the bone defects after the surgery.@*CONCLUSION@#The present data suggest that using CBCT before periodontal regenerative surgery could result in accurate measurement of height and volume of alveolar bone defects. For the purpose of evaluating the effectiveness of regenerative surgery, CBCT could be taken 24 weeks after surgery.

Influence of vitamin D receptor FokI polymorphism on expression of CYP24A1 in periodontal cells / 北京大学学报(医学版)

OBJECTIVE@#There is asingle nucleotide polymorphism (SNP) in the exon 2 of the vitamin D receptor (VDR) gene that can be distinguished using the restriction endonuclease FokI, and accordingly divided into three genotypes: FF, Ff and ff. VDR-FokI polymorphism was the only known SNP that could alter the protein structure of VDR. CYP24A1 is the gene encoding vitamin D 24 hydroxylase and is a vitamin D responsive gene. The influence of rs2228570 on transcriptional activation by VDR in human gingival fibroblasts (hGF) and periodontal ligament cells (hPDLC) was investigated in this study.@*METHODS@#hGF and hPDLC of 12 donors' were primarily cultured and genomic DNA was extracted. A part of genomic DNA with the length of 267 bp was obtained using PCR, which contained the SNP. VDR-Fok I genotypes were determined according to the results of restriction fragment length polymorphism. hGF and hPDLC were stimulated with 10 nmol/L 1α,25 dihydroxy vitamin D3 (1,25OH2D3) or 1 000 nmol/L 25 hydroxy vitamin D3 (25OHD3) for 48 h before RNA was extracted. Then VDR antagonist ZK159222 was used or not used during 1,25OH2D3 or 25OHD3 stimulation with hGF and hPDLC. After 1,25OH2D3 stimulation for 48 h, the proteins in hGF and hPDLC were also collected. The protein expressions of CYP24A1 and VDR were detected using Western blot.@*RESULTS@#Among the 12 donors' cell cultures, the number of FF, ff and Ff genotypes was 4, 3 and 5, respectively.After stimulation with 1,25OH2D3 or 25OHD3 for 48 h,CYP24A1 mRNA levels in FF-hGF were significantly higher than those in other hGF genotypes(1,25OH2D3: F=31.147, P<0.01; 25OHD3: F= 32.061,P <0.01), as was in FF-hPDLC (1,25OH2D3: F=23.347, P<0.01; 25OHD3: F=32.569,P<0.01). When ZK159222 was used before 1,25OH2D3 stimulation, this statistically significant difference disappeared (hGF: F=0.246, P=0.787; hPDLC: F=0.574, P=0.583). When ZK159222 was used before 25OHD3 stimulation, the trend was similar (hGF: F=1.636, P=0.248; hPDLC: F=0.582, P=0.578).After stimulation with 1,25OH2D3 for 48 h, CYP24A1 protein levels in FF-hGF were significantly higher than those in the other hGF genotypes (F=12.368, P <0.01), as was in FF-hPDLC (F=15.749, P <0.01). In hGF and hPDLC, the mRNA or protein expression of VDR of different genotypes was not significantly different under different stimulation conditions.The paired comparison showed that there was no statistically significant difference between the expression of CYP24A1 in hGF and that in hPDLC under all the stimulation conditions, as was the expression of VDR.@*CONCLUSION@#In hGF and hPDLC, the FF-VDR genotype is associated with the more remarkable up-regulation of CYP24A1than the other genotypes, indicating that transcriptional activation of FF-VDR might be higher than those of other vitamin D receptors.

Association between plasma leptin level and systemic inflammatory markers in patients with aggressive periodontitis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Increasing evidence supports an association between periodontitis and systemic diseases. Leptin is involved both in the energy metabolism and inflammatory processes and is suggested to be a link between periodontal infection and systemic health. The present study aimed to evaluate the peripheral leptin concentration in patients with aggressive periodontitis (AgP) and to explore the relationship between leptin and systemic inflammation.</p><p><b>METHODS</b>Ninety patients with AgP visiting the Clinic of the Periodontology Department, Peking University School and Hospital of Stomatology between July 2001 and May 2006, and 44 healthy controls (staff and student volunteers in the same institute) were recruited. Plasma levels of leptin and inflammatory cytokines including interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α) and C-reactive protein (CRP) were measured by enzyme-linked immunosorbent assay. Correlation and multiple linear regression analysis were performed to analyze the association between plasma leptin level and other variables.</p><p><b>RESULTS</b>Plasma leptin level of AgP group was significantly higher than that of the control group (19.7 ± 4.4 ng/ml vs. 7.5 ± 1.3 ng/ml, P < 0.01). After controlling for age, gender, and body mass index, positive correlation was observed between plasma leptin concentration and log-transformed levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α and CRP), and the partial correlation coefficients ranged from 0.199 to 0.376 (P < 0.05). Log-transformed IL-1β and IL-6 levels entered the final regression model (standardized β were 0.422 and 0.461 respectively, P < 0.01).</p><p><b>CONCLUSIONS</b>Elevated plasma leptin concentration may be associated with increased systemic levels of inflammatory markers in AgP patients.</p>

Association between plasma leptin level and periodontal parameters in patients with aggressive periodontitis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To detect the plasma leptin levels in patients with aggressive periodontitis (AgP) and to analyze the relationship between circulating leptin level and periodontal condition.</p><p><b>METHODS</b>A total of 97 patients with AgP and 44 healthy controls were recruited. Detailed clinical examinations were conducted and clinical parameters such as bleeding index (BI), probing depth (PD), attachment loss (AL) were recorded. Plasma leptin level was measured by enzyme-linked immunosorbent assay.</p><p><b>RESULTS</b>The plasma leptin level in AgP group was significantly higher than that of control subjects [(20.0 ± 4.3) µg/L vs. (7.5 ± 1.3) µg/L, P < 0.01)]. The plasma leptin level was positively related to BI, PD and AL, and the r values were 0.647, 0.596 and 0.632 respectively (P < 0.01).</p><p><b>CONCLUSIONS</b>Plasma leptin concentration in AgP patients was significantly elevated compared with healthy controls. Circulating leptin level was positively related to periodontal parameters including BI, PD and AL.</p>

Detection of periodontal pathogens from saliva of type 2 diabetic patients in urban area of Beijing / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the prevalence of periodontal pathogens from saliva of patients with type 2 diabetes mellitus (T2DM), and to characterize the association between the glucose status and periodontal pathogens in oral cavity.</p><p><b>METHODS</b>All the subjects were hypertension patients under regular care at Beijing hypertension prevention and management institute. Whole unstimulated saliva samples were collected from 45 non-diabetic subjects (non-DM group), 80 well-controlled diabetic patients (DM-well group) and 100 poor-controlled diabetic patients (DM-poor group). DNA was extracted from the salivary deposition, Porphyromonas gingivalis (Pg), Tannerella forsythia (Tf) and Treponema denticola (Td) were detected by polymerase chain reaction (PCR) method based on 16SrRNA. Prevalence and quantity of the pathogens under different glucose states were compared and logistic regression model was set to analyze the factors related to each bacterium.</p><p><b>RESULTS</b>The prevalence of Tf in DM-well group and DM-poor group was significantly lower than that of non-DM group [81% (65/80), 80% (80/100) vs 91% (41/45), P = 0.048], meanwhile the quantity of Tf was also lower than that of non-DM group [1.9(2.6), 2.1(5.3) vs 3.4(6.4)] (P > 0.05). With the worsening of glucose control, the quantity of Tf was declining (P = 0.032). However, the prevalence and the quantity of Pg, Td in 3 groups had no statistical differences (P > 0.05). After adjusting age, gender, number of missing teeth and other periodontal parameters, OR of having Tf in saliva from DM-well group and DM-poor group was 0.58 and 0.53, respectively.</p><p><b>CONCLUSIONS</b>Abnormal blood glucose state may affect the colonization of Tf in oral cavity.</p>

Long-term clinical and hematologic effects of non-surgical treatment on aggressive periodontitis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the long-term effects of non-surgical treatment on clinical and hematologic states of patients with generalized aggressive periodontitis (GAgP).</p><p><b>METHODS</b>Patients with GAgP (n = 25) and healthy controls (n = 28) were recruited. The clinical parameters, including probing depth (PD), bleeding index (BI), attachment loss (AL) were examined and recorded. Blood cell variables, including white blood cells (WBC), leukocyte, neutrophil, and lymphocyte counts, as well as serum triglycerides, fasting glucose and protein parameters, including total protein, albumin, globulin, and albumin/globulin ratio (A/G), were analyzed. Twenty-five GAgP patients received non-surgical treatment and the clinical and blood parameters 3 to 7 years after treatment were re-evaluated. Clinical and hematological parameters of the two groups were compared. Comparisons of clinical and hematologic parameters pre- and post-treatment in GAgP group were performed through one-way ANOVA and paired-t test.</p><p><b>RESULTS</b>Elevated white blood cells, neutrophil numbers and serum total protein, globulin levels were observed in patients with GAgP compared to controls[(6.3 ± 2.0)×10(9)cell/L vs.(5.4 ± 1.0)×10(9)cell/L, (4.1 ± 1.8)×10(9) cell/L vs.(3.0 ± 0.9)×10(9) cell/L, (78.2 ± 4.4) g/L vs. (75.6 ± 4.6) g/L and (29.3 ± 3.8) g/L vs.(26.5 ± 3.9) g/L respectively, P < 0.05]. A/G ratio was lower in the GAgP group than in the control group (1.7 ± 0.2 vs.1.9 ± 0.3, P < 0.01). Three to seven years after periodontal treatment, the reduction of PD and BI was observed in GAgP group(P < 0.05). There were significant decreases of WBC count, neutrophil count, serum total protein and globulin level, and significant increases of albumin level and A/G at 3 to 7 years after treatment(P < 0.05).</p><p><b>CONCLUSIONS</b>Non-surgical treatment may have long-term beneficial effect on the periodontal clinical status and hematologic parameters of generalized aggressive periodontitis.</p>

The accuracy of probing depth measurements of undergraduate students and associated factors analysis / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the accuracy of probing depth measurements of undergraduate students in department of periodontology and analyze the cause of measurement errors.</p><p><b>METHODS</b>Thirty-eight dental students from Peking Universty School and Hospital of Stomatology who began their periodontal clinical practice for the first time were recruited. According to principle of clinical teaching, after the students recorded the probing depth of 1-2 periodontitis patients using Williams periodontol probe, an experienced teacher checked the probing depth. The measurements of interproximal sites of Ramfjord index teeth (6 14 41 6) were used as the data of this study. According to the probing depth discrepancies between teacher and the students, all the probing sites were divided in three levels: absolutely consistent sites (probing depth measured by teacher and by student was completely consistent), almost consistent sites (the depth discrepancy between teacher and student was 1 mm), inconsistent sites (the depth discrepancies between teacher and student ≥ 2 mm).</p><p><b>RESULTS</b>The accuracy of probing depth measurements of students decreased with the deepening of probing depth, and the accuracy of probing depth measurements in molar teeth was significantly lower than incisor teeth [58.8% (261/444) vs.73.1% (339/464), P < 0.01]. The main factor associated with the accuracy of probing depth measurements in interproximal sites was the probe's inability to get into gingival col, which accounted for 70.7% (87/123) of the total inconsistent sites.</p><p><b>CONCLUSIONS</b>The correct angle of insertion of the probe in interproximal sites should be reinforced during the course of pre-clinical education of periodontal probing. More attention should be paid to check the probing depth of deep pockets and molar teeth during the clinical practice of undergraduate students.</p>

Alveolar bone loss in nuclear families of aggressive periodontitis and the heredity of root shape / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the status of residual alveolar bone in aggressive periodontitis (AgP) nuclear families and to investigate the influence of teeth with root abnormity on residual alveolar bone and the heredity of root abnormity, the premolar cone-root and proportion of crown and root.</p><p><b>METHODS</b>Nineteen AgP probands (9 males and 10 females) at average age of 24.5 and 38 parents at average age 51.0 were included. A full set of periapical radiographs of all the subjects were taken. The residual alveolar bone of each tooth was measured by the ratio (shown as percentage) of the distance between apical and the alveolar bone crest to the whole root length. The abnormity of roots was detected on a full set of periapical radiographs. All the roots and crowns of teeth were measured. The relationship between the residual bone and the ratio was studied. The heredity grade of the premolar cone-root, proportion of crown and root, and root abnormity were computed.</p><p><b>RESULTS</b>The average residual alveolar bone of probands was less than that of their parents.In 11 families, the father's residual alveolar bone was less than that of the mother's. The average residual alveolar bone of the teeth with root abnormity was less than that of normal teeth. The average residual alveolar bone of the teeth with abnormity of roots and the normal teeth were (67.5 ± 22.2)% and (73.1 ± 18.7)% respectively, with statistical significance (P < 0.001). The heredity grade of the premolar cone-root was 40.1%, the heredity grade of proportion of crown and root was 46.8%, the heredity grade of root abnormity was 30.3%.</p><p><b>CONCLUSIONS</b>The residual alveolar bone of the teeth with root abnormity was less than that of normal teeth in nuclear families. The heritability of the root abnormity, the cone-root and proportion of crown and root in our sample was 0.3-0.5, which means that genetic factors accounted for about one third to half of the efficiency for AgP.</p>