The Safety and Tolerability of Initial Periodontal Therapy Combined With Human Dental Pulp Stem Cell Injection in the Treatment of Chronic Periodontitis

The principal objective of this trial is to investigate the safety and tolerability of human dental pulp stem cells injection in the treatment of chronic periodontitis. The secondary objective is to provide the basis for dosage regimen for further clinical trials and to evaluate the preliminary efficacy.

Initial periodontal therapy involves cleaning, scaling and root planing. The present dose-escalating, randomized, double-blind, blank controlled clinical trial will be conducted to evaluate the safety and tolerability of dental pulp mesenchymal stem cells injection as an adjunct with Initial periodontal therapy in chronic periodontitis. Patients meeting the inclusion criteria will be assigned into five dose groups, in a 3:1 ratio within each group to treat with drug or placebo after initial periodontal therapy. The evaluation will be conducted based on safety and efficacy end points.

Eligibility Criteria:
Inclusion Criteria:

* 18 to 65 years old (including threshold ), unlimited gender.
* Radiological examination of the periodontal defect site shows vertical bone defect, and the probing depth (PD) is 4 to 8 mm.
* Voluntarily participate in the clinical study, understand and sign the informed consent, and comply with the relevant regulations during the study period and within 18 months after the end of the study.

Exclusion Criteria:

* Subjects with severe periodontal diseases (alveolar bone resorption generally exceeds two-thirds of the tooth root length) and affects the study tooth judgment;
* The grade of studied tooth looseness ≥ grade 2 (only buccolingual movement is defined as grade 1; buccolingual and mesiodistal movement is grade 2; vertical loosening is grade 3);
* Subjects with surgical treatment of previous periodontal bone defect sites and adjacent periodontal tissues;
* Subjects with non-steroid anti-inflammatory drug, steroid hormone therapy, and/or hormone (except topical hormones) treatment, bisphosphonates within the previous 3 months before screening;
* Subjects with severe systemic infection within the previous 3 months before screening; or antibiotics treatment within 72 h before screening;
* Subjects with uncontrolled hypertension within 1 month before screening (defined as sitting systolic blood pressure ≥ 160 mmHg or diastolic blood pressure ≥ 95 mmHg after receiving the optimal antihypertensive therapy);
* Subjects with systemic diseases (including but not limited to: malignant tumor or with positive tumor examination during screening, diabetes, heart failure caused by heart disease, myocardial infarction within the first 6 months before screening, angina symptoms within the first 6 months before screening, and congenital heart disease, etc.);
* Subjects who are known to be allergic to any of the materials used in the treatment;
* Subjects with the allergic constitution and previous history of allergy to blood products;
* Laboratory test (any of them meets): abnormal liver function: ALT \> 80 U/L or AST \> 70 U/L; abnormal renal function: serum creatinine (picric acid method) \> 97 μmol/L;
* Subjects with a bleeding tendency or coagulant dysfunction (INR ≥ 1.5 × ULN, or APTT ≥ 1.5 × ULN (except the ones who are receiving anticoagulant therapy)) or serious hematologic diseases (such as grade 3 or above anemia (Hb \< 80 g/L); grade 2 or above thrombocytopenia ( \< 75.0 × 109 /L))
* Viral serology positive (HBsAg, HCV antibody, HIV antibody, treponema pallidum antibody) positive;
* Subjects with unprotected sex within the previous 1 month before the screening;
* Pregnant or lactating women, or subjects with a positive result of β-HCG before the screening, or subjects who are unable or unwilling to take contraceptive measures under the investigator instruction;
* Women with oral contraceptives;
* Subjects with a history of smoking addiction in the previous 12 months before the screening (the number of cigarettes smoked per day ≥ 10);
* Subjects with mental or conscious disorders;
* Subjects who participated in other clinical studies within 3 months before the screening;
* Other circumstances deemed inappropriate by the investigator.