The long-term effect of periodontitis treatment on changes in blood inflammatory markers in patients with generalized aggressive periodontitis.

BACKGROUND: Periodontitis is characterized by local inflammatory conditions in the periodontium, its severe form has been associated with elevated systemic inflammatory markers. However, the long-term effects of periodontal inflammation control on systemic inflammatory markers are unclear. OBJECTIVE: This study aimed to investigate the long-term effects of periodontal therapy on the levels of peripheral venous blood inflammatory markers in patients with generalized aggressive periodontitis (GAgP), all of whom were now diagnosed as Stage III or IV Grade C periodontitis. METHODS: Patients with GAgP were consecutively recruited from April 2013 to August 2014 (T0). Active periodontal treatment (APT) was provided, and follow-ups were conducted over a 3- to 5-year period (T1). Clinical parameters were assessed and fasting venous blood was collected at T0 and T1. Complete blood cell counts were obtained, and biochemical analyses were performed to evaluate the levels of serum components. The correlations between probing depth (PD) and hematological parameters were analyzed. RESULTS: A total of 49 patients with GAgP completed APT and follow-ups. Probing depth (PD) reduced from 5.10 ± 1.07 mm at T0 to 3.15 ± 0.65 mm at T1. For every 1-mm reduction in PD after treatment, the neutrophil count, neutrophil-lymphocyte ratio, and total protein concentration were reduced by 0.33 × 109/L, 0.26, and 1.18 g/L, respectively. In contrast, the albumin/globulin ratio increased by 0.10. CONCLUSION: This study indicated that periodontal therapy may have beneficial effects on peripheral venous blood inflammatory markers in patients with GAgP during long-term observation.

A nomogram-based predictive model for tooth survival in Chinese patients with periodontitis: An 11-year retrospective cohort study.

AIM: To develop a nomogram-based predictive model of tooth survival by comprehensively analysing clinical and radiographic risk factors of tooth loss (TL). MATERIALS AND METHODS: In this study, 3447 teeth of 131 subjects who underwent non-surgical periodontal treatment were examined retrospectively within a mean follow-up period of 11.6 years. The association of risk factors including clinical and radiographic parameters with TL was assessed using univariate and multivariate Cox regression analyses. A nomogram-based predictive model was developed, and its validation and discriminatory ability were analysed. RESULTS: In all, 313 teeth were lost in 94 patients in this study (overall tooth loss [OTL] 9.08%; 0.21 teeth/patient/year). Male, heavy smoking, molar teeth, probing depth (PD), attachment loss (AL), tooth mobility and radiographic bone loss were significantly associated with TL (p < .05). A gradient effect of tooth mobility on TL increased from degree I to III versus none (p < .0001). The area under the curve (AUC) of the model was 0.865. Calibration curve and decision curve analysis demonstrated good performance and high net benefit, respectively. CONCLUSIONS: Adopting a specific nomogram could facilitate the prediction of tooth survival and the development of tailored treatment plans in Chinese patients with advanced periodontitis.

The occurrence of peri-implant mucositis associated with the shift of submucosal microbiome in patients with a history of periodontitis during the first two years.

AIM: To investigate the dynamic changes of peri-implant microbiome in patients with a history of periodontitis and to construct a microbial prediction model. MATERIALS AND METHODS: The prospective study was performed at one month (T1), one year (T2) and two years (T3) after restoration. Clinical examinations [probing depth (PD), bleeding on probing (BOP), suppuration (SUP)], radiographic examinations and sample collection were conducted at three timepoints. Peri-implant sulcular fluid (PISF) was collected and analysed by 16S rRNA gene sequencing. Generalized linear mixed model (GLMM) was used to identify differences. RESULTS: Totally, 168 subjects were assessed for eligibility. Twenty-two patients were recruited in the longitudinal study. Eventually, 67 PISF samples from 24 implants of 12 patients were collected and analysed. Peri-implant microbiome showed increasing diversity and complexity over time. Disease-associated genera Porphyromonas, Tannerella, Treponema and Prevotella dramatically increased from T1 to T3. The prediction model for clinical suppuration at T1 showed a high accuracy of 90%. CONCLUSION: The dysbiosis of peri-implant microbiome increased with time during the two-year observation in patients with a history of periodontitis. Genera of Porphyromonas, Tannerella, Treponema and Prevotella were biomarkers of peri-implant mucositis. Microbiota at the early stage could predict subsequent microbial dysbiosis and clinical suppuration.

A nomogram prediction for mandibular molar survival in Chinese patients with periodontitis: A 10-year retrospective cohort study.

AIMS: To develop a nomogram prediction model of mandibular molar survival by comprehensively analysing clinical and radiographic risk factors of mandibular molar loss. MATERIALS AND METHODS: Four hundred and seventy-eight mandibular molars of 139 subjects who underwent non-surgical periodontal treatment were examined retrospectively within a mean follow-up period of 11.1 years. The association of risk factors including clinical and radiographic parameters with mandibular molar loss was assessed using univariate and multivariate Cox regression analyses. A nomogram prediction model was developed, and the validation and discriminatory ability of it were analysed. RESULTS: Hundred and four molars were lost in this study. Probing depth (PD), attachment loss (AL), furcation involvement (FI), bleeding on probing (BOP), tooth mobility and radiographic bone loss were significantly associated with tooth loss (p < .01). A gradient effect of degree of FI on mandibular molar loss existed increasing from degree Ⅱ (HR = 2.37, 95% CI: 1.48, 3.79) to Ⅲ (HR = 5.61, 95% CI: 3.01, 10.45) versus none & degree Ⅰ. The area under the curve (AUC) of the model was 0.891. The calibration curve and decision curve analysis demonstrated good performance and high net benefit of nomogram, respectively. CONCLUSIONS: A specific nomogram could be adopted to predict the mandibular molar survival and formulate tailored treatment plans in Chinese.

Association of CYP1A1 rs1048943 variant with aggressive periodontitis and its interaction with hyperlipidemia on the periodontal status.

BACKGROUND AND OBJECTIVE: CYP1A1 rs1048943 polymorphism was reported to be correlated with periodontitis; however, its association with aggressive periodontitis (AgP) has not yet been investigated. The aim of the study was to investigate the association between the CYP1A1 gene rs1048943 variant with generalized aggressive periodontitis (GAgP) and platelet activation and analyse whether its interaction with hyperlipidemia affects periodontal status in a Chinese population. METHODS: A case-control study of 224 GAgP patients and 139 healthy controls was conducted. The clinical parameters of probing depth (PD), attachment loss (AL) and bleeding index (BI) were recorded. Platelet count (PLT), platelet distribution width (PDW), platelet large cell ratio (PLCR), mean platelet volume (MPV), serum total cholesterol (TC), triacylglycerol (TG), high and low-density lipoprotein (HDL and LDL) were also measured. The CYP1A1 rs1048943 SNP was genotyped by time-of-flight mass spectrometry. Logistic and linear regression models were used to measure correlation. RESULTS: The CYP1A1 rs1048943 AG/GG genotype was associated with GAgP (OR = 1.56, 95%CI: 1.01, 2.42), PD, AL and decreased PDW, PLCR and MPV after adjustment for covariates. Gene-lipid interactions were found between CYP1A1 rs1048943 and HDL for PD (Pinteraction  = 0.0033), BI (Pinteraction  = 0.0311) and AL (Pinteraction  = 0.0141) and between CYP1A1 rs1048943 and LDL for PD (Pinteraction  = 0.013) among patients with GAgP. CONCLUSION: The G allele of the CYP1A1 rs1048943 gene was associated with GAgP, periodontal status and platelet-related inflammation status in a Chinese population. Hyperlipidemia could modulate the effect of CYP1A1 rs1048943 on the periodontal status of GAgP.

Microbiome in maintained periodontitis and its shift over a single maintenance interval of 3 months.

AIM: To assess the subgingival microbial shift of maintained periodontitis treated by ultrasonic scaling (US) or air polishing (AP) during a 3-month maintenance interval. MATERIALS AND METHODS: We conducted a 12-week randomized split-mouth controlled trial with US and AP in 17 maintained subjects (bleeding on probing [BOP%] ≤25%, probing depth [PD] ≤5 mm). They were monitored at baseline, week 2, week 8 and week 12. The V3-V4 region of the 16S rDNA from 136 subgingival plaque samples was sequenced and analysed. RESULTS: Treatment by US or AP could effectively reduce the PD, microbial richness, diversity, periodontitis-associated microbiota and pathogenic metabolism in maintained periodontitis. Bacteria recolonized after treatment and returned to the pre-treatment level 12 weeks after treatment. Ultrasonic scaling group demonstrated slight advantage in reducing BOP (%), pathogenic bacteria and metabolism than AP group. Pathogenic microbiota and commensal microbiota kept a balance in subgingival community of maintained patients during the 3-month interval. CONCLUSIONS: Treatment by US or AP effectively reduced the pathogenicity of subgingival microbiome by reducing microbial diversity, proportion of periodontitis-associated microbiota and pathogenic metabolism. It helped to keep a balanced subgingival community and stable periodontal condition over a single maintenance interval of 3 months.

Clinical performance of non-surgical periodontal therapy in a large Chinese population with generalized aggressive periodontitis.

AIM: This study aimed to evaluate clinical performance of non-surgical periodontal treatment (NSPT) and its influential factors in a large Chinese population with generalized aggressive periodontitis (GAgP). MATERIAL AND METHODS: Longitudinal periodontal examination data of 1,004 GAgP patients (numbers of patients with observation periods 6 weeks~, 3 months~, 6 months~, 1 year~, 3 years~ and >5 years were 203, 310, 193, 205, 70 and 23, respectively) were extracted from a hospital-based electronic periodontal charting record system and analysed by multilevel analysis. RESULTS: Mean probing depth (PD) and attachment loss (AL) reductions at patient level were 1.17 mm and 1.07 mm, respectively. Multilevel analysis demonstrated PD reductions after maintenance were mainly influenced by frequency of supportive periodontal treatment (FSPT), gender, adjunctive systemic use of antibiotics, baseline mobility, tooth type and baseline PD and bleeding index reductions were mainly influenced by FSPT, adjunctive systemic use of antibiotics, baseline AL, baseline mobility, tooth type and baseline PD. CONCLUSION: The clinical performance of NSPT on patients with GAgP was proved in the large Chinese population. Outcomes of NSPT were mainly influenced by FSPT, adjunctive systemic use of antibiotics, baseline mobility, tooth type and baseline PD.

[Association between FADS1 rs174537 polymorphism and serum proteins in patients with aggressive periodontitis].

OBJECTIVE: To investigate the potential association between FADS1 rs174537 polymorphism and serum proteins in patients with aggressive periodontitis, which may provide benefits for diagnosis and treatment of aggressive periodontitis. METHODS: A total of 353 patients with aggressive periodontitis (group AgP) and 125 matched controls (group HP) were recruited in the study. Genotyping of FADS1 rs174537 and serum biochemical indexes were tested at the study's start. The relationships between the levels of TP, GLB, ALB, A/G and genotyping were analyzed. RESULTS: (1) The detection rate of allele G in group AgP was higher than that in group HP(68.1% vs. 61.2%, P=0.046,OR=1.35,95% CI 1.00-1.83); the detection rate of genotype GG in group AgP was higher than in group HP(45.5% vs. 34.4%,P=0.029, OR=1.60, 95% CI 1.05-2.44). (2) In group AgP, the patients with GG genotype exhibited significantly lower TP, GLB than the patients with GT+TT genotype [(77.08 ± 7.88) g/L vs. (79.00 ± 4.66) g/L, P=0.007; (28.17 ± 7.63) g/L vs.(29.88 ± 3.49) g/L,P=0.007) and the higher A/G(1.72 ± 0.22 vs.1.67 ± 0.22, P=0.040), but there was no significant difference in ALB between the patients with GG genotype and the patients with GT+TT genotype. In group HP, there were no significant differences in TP, GLB, A/G and ALB between individuals with genotype GT+TT and with genotype GG. (3)Compared with individuals with genotype GT+TT in group HP, the AgP patients with genotype GT+TT exhibited significantly higher TP, GLB [(79.00 ± 4.66) g/L vs. (75.20 ± 4.53) g/L, P<0.01; (29.88 ± 3.49) g/L vs.(26.55 ± 2.94) g/L, P<0.01) and the lower A/G(1.67 ± 0.22 vs. 1.88 ± 0.30, P<0.01), but there was no significant difference in ALB. There were no significant differences in TP, GLB, A/G and ALB the between the AgP patients with genotype GG and the healthy subjects with the same genotype either. CONCLUSION: FADS1 rs174537 polymorphism is associated with aggressive periodontitis. The patients with genotype GG in group AgP had relatively lower TP,GLB and higher A/G. Genotype GG might be a risk indicator for aggressive periodontitis by reducing host defense capability and contributing to inflammatory response in the occurrence and development of aggressive periodontitis.

Dynamics of the Streptococcus gordonii Transcriptome in Response to Medium, Salivary α-Amylase, and Starch.

Streptococcus gordonii, a primary colonizer of the tooth surface, interacts with salivary α-amylase via amylase-binding protein A (AbpA). This enzyme hydrolyzes starch to glucose, maltose, and maltodextrins that can be utilized by various oral bacteria for nutrition. Microarray studies demonstrated that AbpA modulates gene expression in response to amylase, suggesting that the amylase-streptococcal interaction may function in ways other than nutrition. The goal of this study was to explore the role of AbpA in gene regulation through comparative transcriptional profiling of wild-type KS1 and AbpA(-) mutant KS1ΩabpA under various environmental conditions. A portion of the total RNA isolated from mid-log-phase cells grown in 5% CO2 in (i) complex medium with or without amylase, (ii) defined medium (DM) containing 0.8% glucose with/without amylase, and (iii) DM containing 0.2% glucose and amylase with or without starch was reverse transcribed to cDNA and the rest used for RNA sequencing. Changes in the expression of selected genes were validated by quantitative reverse transcription-PCR. Maltodextrin-associated genes, fatty acid synthesis genes and competence genes were differentially expressed in a medium-dependent manner. Genes in another cluster containing a putative histidine kinase/response regulator, peptide methionine sulfoxide reductase, thioredoxin protein, lipoprotein, and cytochrome c-type protein were downregulated in KS1ΩabpA under all of the environmental conditions tested. Thus, AbpA appears to modulate genes associated with maltodextrin utilization/transport and fatty acid synthesis. Importantly, in all growth conditions AbpA was associated with increased expression of a potential two-component signaling system associated with genes involved in reducing oxidative stress, suggesting a role in signal transduction and stress tolerance.

Oral microbiome in chinese patients with aggressive periodontitis and their family members.

AIM: To investigate the microbiome composition in Chinese patients with aggressive periodontitis (AgP), and to compare the similarity of bacterial profiles between AgP patients and their family members. MATERIAL AND METHODS: Pooled subgingival plaque and saliva samples were collected from 10 AgP patients and 10 of their first-degree blood relatives with chronic periodontitis. DNA amplicons of the V1-V3 hypervariable region of the bacterial 16S rRNA gene were generated, and were subjected to 454-pyrosequencing. RESULTS: In subgingival plaque, the unweighted UniFrac distances between family members were significantly lower than those in unrelated participants (p = 0.039). Compared with the relatives, the microbiota of subgingival plaque and saliva from AgP patients revealed significantly lower taxonomic diversity. High relative abundance of Porphyromonas gingivalis (about 35.88%) was detected in subgingival plaque from AgP patients. The relative abundance of P. gingivalis and Red complex pathogens (P. gingivalis, Treponema denticola and Tannerella forsythia) in the subgingival plaque and saliva samples from the same individual were significantly correlated in AgP patients (ρ= 0.687 and 0.678, respectively). CONCLUSIONS: There is a kinship in the phylogenetic architecture of microbiota among Chinese AgP patients and their family members. P. gingivalis might be a predominant pathogen in these Chinese AgP patients.

[Clinical and putative periodontal pathogens' features of different sites with probing depth reduction after non-surgical periodontal treatment of patients with aggressive periodontitis].

OBJECTIVE: To evaluate the differences of clinical parameters and putative periodontal pathogens in sites of different probing depth (PD) reduction after non-surgical periodontal treatment in patients with aggressive periodontitis (AgP). METHODS: Clinical examinations including plaque index, probing depth (PD), attachment level (AL) and bleeding index (BI), and full-mouth periapical photographs were collected from 20 patients with AgP. All the patients received non-surgical periodontal treatment, including oral hygiene instruction, supra-gingival scaling, subgingival scaling and root planing (SRP) and were followed up for 6 months post-therapy. Gingival crevicular fluids (GCF) were collected at 1 site in each quadrant before and at the end of 6 months post-therapy. Six kinds of putative periodontal pathogens and 6 kinds of short chain fatty acids (SCFAs) were detected in the GCF samples. RESULTS: The baseline clinical parameters of PD, AL and BI, the baseline concentration of succinic acid, acetic acid, propionic acid and butyric acid, and the prevalence of Treponema denticola were significantly higher in sites with PD reduction more than 2 mm sites compared with PD reduction no more than 2 mm sites [(7.7 ± 1.2) mm vs. (5.1 ± 1.8) mm, (6.3 ± 1.9) mm vs. (4.5 ± 2.2) mm, 3.8 ± 0.4 vs. 3.3 ± 0.8, 1.66 mmol/L vs. 1.10 mmol/L, 31.67 mmol/L vs.17.78 mmol/L, 3.31 mmol/L vs.1.95 mmol/L, 84.6% vs. 56.1%, P<0.05]. However, there were no significant differences in the clinical parameters, the 6 kinds of putative periodontal pathogen detection and SCFAs concentration between the 2 groups at the end of 6 months post-treatment. In sites with PD>5 mm at the end of 6 months post-therapy, all were found with red complex bacteria infection. CONCLUSION: The baseline clinical parameters are important factors in predicting PD reduction after non-surgical periodontal treatment in patients with AgP. In sites with deep pockets after non-surgical periodontal treatment, the active control of red complex bacteria is recommended.

[Analysis of serum IgG titers to Aggregatibacter actinomycetemcomitans serotype c in aggressive periodontitis patients].

OBJECTIVE: To analyze the serum IgG titers to Aggregatibacter actinomycetemcomitans(Aa) and associated factors in patients with aggressive periodontitis (AgP). METHODS: Venous blood samples were collected from 62 AgP patients and 45 periodontal healthy controls, unstimulated whole saliva and pooled subgingival plaque samples of AgP patients were also collected for the detection of Aa (PCR method). Serum IgG titers to Aa serotype c were measured by enzyme-linked immunosorbnent assay (ELISA). RESULTS: The detection rates of serum IgG to Aa serotype c in the AgP patients and the healthy controls were both 100%. The AgP patients exhibited significantly higher IgG titers to Aa serotype c than the healthy controls (11.1±1.9 vs. 9.1±1.8, P<0.01). There was no significant difference in serum IgG levels to Aa serotype c and in the prevalence of high-responding patients to Aa serotype c between the incisor-first molar type AgP patients and generalized AgP patients. Serum IgG titers to Aa serotype c in the Aa-positive AgP patients (the patients who were Aa-positive in subgingival plaque or saliva) were significantly higher than those of the Aa-negative patients (11.9±1.3 vs. 10.7±2.1, P<0.05). CONCLUSION: Serotype c was the main serotype of Aa in Chinese patients with AgP. Serum IgG responses in generalized AgP patients were comparable to those in incisor-first molar type AgP patients.

Immune dysregulation and macrophage polarization in peri-implantitis.

The term "peri-implantitis" (peri-implantitis) refers to an inflammatory lesion of the mucosa surrounding an endosseous implant and a progressive loss of the peri-implant bone that supports the implant. Recently, it has been suggested that the increased sensitivity of implants to infection and the quick elimination of supporting tissue after infection may be caused by a dysregulated peri-implant mucosal immune response. Macrophages are polarized in response to environmental signals and play multiple roles in peri-implantitis. In peri-implantitis lesion samples, recent investigations have discovered a considerable increase in M1 type macrophages, with M1 type macrophages contributing to the pro-inflammatory response brought on by bacteria, whereas M2 type macrophages contribute to inflammation remission and tissue repair. In an effort to better understand the pathogenesis of peri-implantitis and suggest potential immunomodulatory treatments for peri-implantitis in the direction of macrophage polarization patterns, this review summarizes the research findings related to macrophage polarization in peri-implantitis and compares them with periodontitis.

[Relationship between volatile fatty acids and Porphyromonas gingivalis and Treponema denticola in gingival crevicular fluids of patients with aggressive periodontitis].

OBJECTIVE: Short chain fatty acids (SCFAs), such as succinic acid, acetic acid, propionic acid, butyric acid, etc. are metabolic product of putative periodontal pathogens, which play significant roles in periodontitis. The aim of this study was to analyze the relationship between Porphyromonas gingivalis (P. gingivalis), Treponema denticola (T. denticola), and the concentration of SCFAs in gingival crevicular fluid (GCF) of patients with aggressive periodontitis (AgP). METHODS: GCF was sampled from 4 sites per individual in 20 patients with AgP and 14 healthy controls. Concentrations of SCFAs, including succinic acid, acetic acid, propionic acid, butyric acid, and isovaleric acid in the supernant of GCF were analyzed by high performance capillary electrophoresis (HPCE), P. gingivalis and T. denticola in the deposit of the same GCF were detected by PCR with their electrophoretic band quantified. RESULTS: The concentrations of succinic acid, acetic acid, propionic acid, butyric acid, and isovaleric acid, the prevalence and PCR band quantity of P. gingivalis and T. denticola in GCF were all significantly higher in patients with AgP than that of healthy controls. In patients with AgP, butyric acid concentration was significantly higher in P. gingivalis positive sites than negative sites [2.87 (0.99, 4.36) mmol/L vs. 0.33 (0.00, 1.44) mmol/L, P<0.05], the concentrations of succinic acid, acetic acid, propionic acid, butyric acid, and isovaleric acid were positively correlated with PCR band quantity of P. gingivalis (r value was 0.334, 0.548, 0.411, 0.493, 0.273, respectively, P<0.05); the concentrations of SCFAs were significantly higher in T. denticola positive sites than negative sites: succinic acid, 1.67 (1.15, 2.11) mmol/L vs. 0.80 (0.48, 1.06) mmol/L; acetic acid, 31.95 (23.77, 43.13) mmol/L vs.12.51 (7.57, 15.69) mmol/L; propionic acid, 11.86 (6.55, 14.98) mmol/L vs. 2.82 (1.71, 7.03) mmol/L; butyric acid, 3.45 (2.41, 4.78) mmol/L vs. 0.54 (0.00, 1.56) mmol/L; isovaleric acid, 2.23 (1.05, 3.85) mmol/L vs. 0.62 (0.00, 2.33) mmol/L. The concentrations of succinic acid, acetic acid, propionic acid, butyric acid were positively correlated with PCR band quantity of T. denticola (r value was 0.443, 0.702, 0.625, 0.557, respectively, P<0.05). CONCLUSION: SCFAs concentrations reflect the quantity of P. gingivalis and T. denticola in patients with AgP, and may be an indicator to the disease progression in patients with AgP.

[Predictive model for post-treatment tooth loss of patients with aggressive periodontitis].

OBJECTIVE: To establish a predictive model for long-term tooth loss of patients with aggressive periodontitis (AgP) after periodontal treatment. METHODS: Patients diagnosed as AgP in Department of Periodontology, Peking University School and Hospital of Stomatology, who were re-evaluated 3 to 11 years after periodontal treatment were enrolled (n=85). Logistic regression was performed to select background, periodontal and radiographic factors which were related to long-term post-treatment tooth loss. A predictive model was built and analyzed by receiver operator characteristic (ROC) curve. RESULTS: After periodontal treatment, 55 teeth from 22 patients lost further. High prevalence of baseline bone loss, root abnormality, and residual severe bleeding sites, as well as poor compliance to maintenance were detected as risk factors in the predictive model. ROC analysis found the sensitivity and specificity of the model could reach up to 80% simultaneously. CONCLUSION: Predictive model for post-treatment tooth loss of patients with AgP is an important adjunct in clinical practice.

[Clinical evaluation of periodontal intrabony defects treated with a reconstituted bovine porous bone mineral containing bone morphogenetic proteins].

OBJECTIVE: To compare the outcomes of bovine porous bone mineral (BPBM) containing bone morphogenetic proteins (BMP) and BPBM alone in periodontal intra-bony defects. METHODS: In the study, 22 intrabony defects of 9 patients with periodontitis were recruited. All the patients had at least one pair of intrabony defects of ≥3 mm. The split-mouth and single blind methods were used. The defects were randomly assigned to BPBM containing BMP (test) or BPBM alone (control). After debridement, the intrabony defects were treated by bone graft. Assessments at baseline and after 6 months included plaque index, attachment level, probing pocket depth, bleeding indexes on probing and gingival recession. The early wound-healing, adverse effects and patients' perceptions were also recorded. RESULTS: The gain in clinical attachment was (3.0±1.2) mm in the test group and (3.2±1.1) mm in the control group. The pocket reduction was (3.4±1.5) mm in the test group and (2.8±1.0) mm in the control group. The reduction of bleeding index was 1.9±1.3 in the test group and 2.3±0.8 in the control group. There was no statistical difference between the test group and control group (P>0.05). CONCLUSION: Both treatment modalities led to similar significant clinical improvements.

[A short-term clinical evaluation of periodontal treatment with an Er:YAG laser for patients with chronic periodontitis: a split-mouth controlled study].

OBJECTIVE: To compare the short-term clinical effects following non-surgical periodontal treatment with Er:YAG laser or with combination of ultrasonic subgingival scaling and root planing with hand instrument (SRP) for patients with chronic periodontitis. METHODS: In the study, 17 patients with chronic periodontitis were randomly treated in a split-mouth design with Er:YAG laser (test group) or a combination of ultrasonic subgingival scaling and root planing with hand instrument (control group). The degree of discomfort experienced during the treatment was graded by the patient using visual analogue scale (VAS) immediately after the completion of test and control treatment procedures. The following clinical parameters were recorded by a calibrated and blinded examiner: plaque index (PLI), bleeding index (BI), probing depth (PD) and attachment loss (AL). RESULTS: The mean VAS score of Er:YAG laser treatment [3 (2, 4.5)] was significantly lower than that of control treatment [5 (4, 6), P=0.013]. Both the groups showed significant reduction of PLI, PD, AL and BI values 2 months and 4 months after treatment. For sites with PD≥4 mm at baseline, the sites treated with Er:YAG laser demonstrated mean PD change from (5.6±1.1) mm to (3.6±1.1) mm and to (3.4±1.0) mm at the end of 2 months and 4 months respectively and demonstrated mean AL change from (5.1±1.5) mm to (3.9±1.6) mm and to (3.8±1.7) mm at the end of 2 months and 4 months respectively, meanwhile the BI value showed significant decrease, P=0.000; the sites treated with conventional SRP demonstrated mean PD change from (5.6±1.1) mm to (3.8±1.1) mm and (3.5± 1.0) mm at the end of 2 months and 4 months respectively and demonstrated mean AL change from (4.8±1.6) mm to (3.8±1.6) mm and (3.6±1.8) mm at the end of 2 months and 4 months respectively, and the BI value also showed significant improvement. No statistical difference for all clinical parameters were found between the two treatment groups. CONCLUSION: The present results indicate that non-surgical periodontal therapy with Er:YAG laser is safe and effective, and Er:YAG laser therapy could be used for patients who was sensitive to pain.

[Correlation study on polymorphisms of vitamin D receptor gene in patients with periodontitis].

OBJECTIVE: To investigate the relationship between vitamin D receptor (VDR) gene polymorphisms and periodontitis. METHODS: Ninety patients with aggressive periodontitis(AgP), 34 patients with chronic periodontitis and 91 healthy controls were recruited in this study. VDR gene was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with Taq I restriction endonuclease. RESULTS: The detection frequency of Tt genotype was higher in the aggressive periodontitis patients than in the healthy controls (16.7% vs 7.7%, P>0.05). The difference between the female aggressive periodontitis patients and healthy controls (20.8% vs 4.2%, P<0.05) was statistically significant, but no difference was found between the male patients and controls (10.8% vs 11.6%, P>0.05). There was a strong association between aggressive periodontitis and Tt genotype in females (AgP patients vs healthy controls, OR=6.02). The detection frequency of Taq I ER-alpha genotypes was not statistically different between the chronic periodontitis patients and healthy controls. CONCLUSION: In female Han Chinese population, the Tt VDR genotype may be associated with aggressive periodontitis.

[Effect of periodontal mechanical treatment on periodontal pathogenic bacteria in gingival crevicular fluid of chronic periodontitis patients].

OBJECTIVE: To evaluate the subgingival prevalent rates of 6 periodontal pathogenic bacteria in gingival crevicular fluids of CP patients before and after treatment, to analyze the relationship between the prevalent variance and periodontal clinical parameters, and to provide a microbiologic method of evaluating curative effect and estimating the prognosis. METHODS: Gingival crevicular fluids of 13 CP patients were collected at baseline, 2 weeks, 2 months and 4 months after periodontal mechanical treatment. Also, gingival crevicular fluids were collected from 11 healthy subjects. Six periodontal pathogenic bacteria including Actinobacillus actinomycetemcomitans (Aa), Porphyromonas gingivalis(Pg), Tannerella forsythensis (Tf), Prevotella intermedia (Pi), Fusobacterium nucleatum(Fn), Prevotella nigrescens (Pn) were detected by 16S rRNA based PCR. RESULTS: The PLI, PD, BI of the CP patients 2 months and 4 months after periodontal mechanical treatment were evidently less than those before treatment. These 4 months after treatment were a little more than those 2 months after. The six bacteria were more frequently detected in the CP patients at baseline than in healthy controls. The prevalent rates of Tf (42.1%, 73.7%, 70.2%), Pg (47.4%, 68.4%, 77.2%), Aa (15.8%, 22.8%, 7.0%), Pn (38.6%, 57.9%, 64.9%), Pi(15.8%, 38.6%, 42.1%) 2 weeks, 2 months and 4 months following treatment were significantly lower than those at baseline (Tf 96.5%, Pg 93.0%, Aa 36.8%, Pn 86.0%, Pi 84.2%), but the prevalent rates of all the detected bacteria 2 months after treatment were higher than those at 2 weeks after. CONCLUSION: Tf, Pg, Aa, Pn and Pi may cooperate in the development of CP. The changes of periodontal pathogenic bacteria could be detected before the changes of clinical parameters and the patients should be re-evaluated and re-treated regularly within 2 months after treatment.

[Clinical significance of the change in serum IgG titers respond to Aggregatibacter actinomycetemcomitans in chronic periodontitis patients].

OBJECTIVE: To characterize serum antibody response to Aggregatibacter actinomycetemcomitans (Aa) serotype c in chronic periodontitis (CP) patients, and to observe the correlation of IgG titer with clinical parameters. METHODS: Venous blood samples were collected from 30 CP patients and 45 periodontal healthy controls, and unstimulated whole saliva and pooled subgingival plaque samples of CP patients were also collected for detection of Aa (PCR method). Serum IgG titers to Aa were measured by Enzyme-Linked Immunosorbent Assay (ELISA). RESULTS: The detection rates of serum IgG to Aa serotype c in CP patients and healthy controls were both 100%. CP patients exhibited significantly higher IgG titers to Aa serotype c than healthy controls [(10.9+/-1.9) vs (9.1+/-1.8), P=0.000], and the prevalence of high-responding patients in CP group was also significantly higher than that of healthy controls (23.3% vs 0%, P=0.003). Serum IgG titers to Aa serotype c in Aa-positive CP patients (Aa-positive in subgingival plaque or saliva, n=7) were significantly higher than those of Aa-negative patients [(12.6+/-1.6) vs (10.4+/-1.7), P=0.005)]. Serum IgG titers to Aa in CP patients tended to be positively related to mean probing depth of whole mouth (r=0.344, P=0.068). CONCLUSION: Serotype c was the main serotype of Aa in CP patients. Serum IgG antibody to Aa serotype c did not seem to have a protective effect against periodontal infection.