| Background:The main focuses of this project is periodontal clinical treatment and clinical applications, which contains two major parts:one is the relationship between periodontitis&diabetes mellitus and the effect of periodontal treatment on glycemic control, another one is clinical application research, including the efficacy of minocycline-HCl on root conditioning and the aesthetic thinking in the pre-surgical design of crown lengthening surgery.Periodontal disease is a kind of disease that affects the periodontal supportive tissue.The common types of periodontal diseases are gingivitis and periodontitis, also includes some non-inflammatory diseases. Periodontitis has the correlation with systemic diseases, such as hypertension, diabetes, leukemia. As the incidence of diabetes increased year by year, more and more research focused on the relationship between diabetes and periodontitis. Diabetes is a chronic metabolic disease with the main manifestation of hyperglycemia. Hyperglycemia is caused by insufficient insulin secretion correlated with dysfuncion of pancreatic β-cell, and liver and muscle insulin resistance. Hyperglycemia can cause long-term damage to systemic organs (such as the heart, eyes, kidneys, nerves and blood vessels). From the1960s, many studies focused on the relationship and corresponding mechanism between periodontitis and diabetes, and most of the studies suggested that diabetic hyperglycemia may activate a series of signaling pathways causing local inflammation, which increase periodontal tissue destruction. And so many epidemiological data has confirmed the effect. However, there is no clear data specific the relationship between the glucose concentrations and destruction of periodontitis. Periodontitis can cause chronic inflammation, resulting in elevated levels of serum C-reactive protein, IL-6and fibrinogen, furtherly aggravating insulin resistance. Periodontal treatment can remove local dental plaque, release imflamation. so periodontal treatment may improve glycemic control. However, the results of clinical intervention trials are disputed. Part of the studies reported that periodontal treatment can improve glycemic control, but the others found little effect. In order to solve these issues in the clinical research of diabetes and periodontitis, the first part of this topic carried out a community survey, the case-control study to provide more definitive data on the relationship between periodontitis and diabetes risk factors, and observe the effects of periodontal initial therapy on glycemic control&periodontal condition by a single-blind randomized controlled clinical trial.The second part selected two major issues in periodontal practice-get better prognosis and esthetics, and bring two new applications:minocycline hydrochloride ointment in root conditioning and aesthetics in crown lengthening surgery. It has always been a major purpose and problem that get much more clinical attachment. Even though the biological bone material, enamel matrix proteins and other materials has been confirmed to improve the clinical efficacy, the complexity of the operation and excessive cost limit these applications. Minocycline hydrochloride has the demineralization characteristics as low PH value characteristics, which may be used in root conditioning. Except that, minocycline has anti-bacterial and anti-collagenase properties. If it can be used in root conditioning during flap surgery, it would improve the clinical efficacy without raise the difficulty and cost of surgery. Therefore, we designed a vitro and vivo study to evaluate the effect of minocycline on root conditioning. With the progression of human civilization, the demand for aesthetics increased day by day. We bring aesthetic consideration to surgical crown lengthening in order to obtain the aesthetic effect of the anterior region.Part I:The relationship between diabetes&periodontitis, and the effect of periodontal initial therapy on diabetic patientsObjectives:This study aims to observer the correlation between periodontitis and diabetes in community population, and evaluate the effects of scaling and root planing (SRP) as well as enhanced root planing (ERP) on the glycemic control and periodontal condition of patients with type2diabetes mellitus (T2DM) and chronic periodontitis. Materials and methods:200non-diabetic and200diabetic persons was randomly selected from community population. The periodontal and glycemic condition of selected samples were recorded. Multiliner regression model was used to analyze the influence of HbA1c and FPG on periodontal condition. Patients with T2DM and chronic periodontitis were randomly assigned to treatment (n=49) and control (n=22) groups. The treatment group was treated with SRP, whereas the control group remained untreated. After three months, the patients in the treatment group were randomly divided into sub-ERP (n=25) and subprophylaxis (n=24) groups, which were treated with ERP and prophylaxis, respectively. Results:A total of193non-diabetic and196diabetic persons finished the survey. The odds ratio of diabetes to non-diabetes on periodontitis is2.52(95%C1:1.23,5.66). Glycemic condition can affect PD and CAL. HbA1c and FPG levels in the treatment group decreased after SRP. The changes in the HbA1c level in this group was significantly greater than it in the control group (p<0.05). The periodontal condition significantly improved in the treatment group compared with that in the control group (p<0.01). The decrease of the periodontal pocket depth in the sub-ERP group was more significant than that in the sub-prophylaxis group (p<0.05). Conclusions:The prevalence of periodontitis in diabetic population is high than in non-diabetic population. SRP can benefit the improvement of glycemic control and periodontal condition. In addition, ERP can further improve the periodontal condition of patients with T2DM.Part Ⅱ:Periodontal clinical studyStudy1:The effect of Minocycline-HCl paste on root conditioning:vitro and vivo studyObjectives:This study aimed to investigate the root conditioning effects of2%minocycline-HCl paste during periodontal flap surgery. Materials and Methods:In vitro, cementum slices affected by periodontitis were randomly conditioned with2%minocycline-HCl paste,2%Minocycline-HCl liquid and0.9%normal saline respectively. Then NIH3T3cells were cultured. Cellular density/shape attached to each slices were observed and the viability/proliferation were tested. In vivo.21deep periodontal pockets were treated with flap surgery and root conditioning randomly with2%minocycline-HCl paste or0.9%normal saline. The periodontal parameters were measured before surgery,3and6months after surgery. Results:In vitro, NIH3T3cells attached to minocycline-HCl conditioning groups had better density/extension than normal saline group; cell growth was better on minocycline-HCl groups than normal saline group on3rd,5th and7th day; little difference was found between paste and liquid surfaces. In vivo, greater reduction of CAL and PD was found in minocycline-HCl group than normal saline3months and6months after surgery. Conclusions:The study suggests that conditioning roots with minocycline-HCl paste during flap surgery tends to increase clinical attachment and reduce periodontal pocket further, which might be correlated with better cell attachment and growth on conditioned surface.Study2:The effect of esthetic design on crown lengtheningObjectives:To design an esthetic crown lengthening surgery procedure for "gummy smile" patients to achieve the aesthetic requirements at the anterior area. Materials and methods:First, design the postsurgical gingival margin of teeth#13-#23on study cast, and copy it to oral cavity by temporarily veneer with composite resin for doctor and patient to assess; then fabricate the "final template" for guidance during surgical procedure according to the "temporary veneer". Results:the postoperative gingival margin was coincident with preoperative design; Satisfactory degree of patients improved. Conclusion:"temporary veneer+final template" for crown lengthening can get better esthetic outcomes. |
