[Research on the pathogeny of black tooth stain and association between black tooth stain and primary dentition caries in children].

Purpose: To investigate the relationship between polymorphism of cytochrome P450, family 2, subfamily A, polypeptide 6(CYP2A6) and periodontitis, the expression of inflammatory cytokines in 123 Han smokers.

Methods: From October 2018 to October 2019, a total of 123 smokers with periodontitis were selected as the experimental group, and 125 non-smokers as the control group. The general data of the patients were collected, including age, gender, body mass index (BMI), chewing and brushing habits, as well as molar condition; plaque index (PLI), gingival bleeding index (BI), periodontal probing depth (PD) and attachment loss (AL) were detected.

[Clinical effect of Nd:YAP laser in periodontal regeneration surgery].

Purpose: To evaluate the clinical effect of Nd:YAP laser in periodontal regeneration surgery.

Methods: Four weeks after primary periodontal treatment, 48 patients, 60 teeth with bone defect and probing depth(PD) ≥6 mm, bleeding on probing (BOP)(+), were randomly divided into two groups. Patients in the experimental group were treated with Nd:YAP laser combined with periodontal regeneration surgery, while patients in the control group were treated with conventional periodontal regeneration surgery alone.

Pulp status of teeth in patients with chronic advanced periodontitis.

Objective: This study aimed to evaluate the dental-pulp status in patients with chronic advanced periodontitis.

Materials And Methods: Sixty teeth were extracted from patients with advanced periodontitis. Before extraction, electric pulp tests were conducted to explore the real state of the pulp.

[Study on improving the practical ability of specialized nurses in micro-endodontics by cooperative medical and nursing training].

Purpose: To explore the effect of cooperative training between doctors and nurses on improving the practical ability of micro-endodontics specialist nurses.

Methods: Twenty-two nurses in the Department of Endodontics were trained by specialist directors and doctors. The head of department nursing explained in the form of teaching and simulated exercises of medical and nursing training.

[Bone regeneration effect of injectable-platelet rich fibrin (I-PRF) in lateral sinus lift: a pilot study].

Purpose: The aim of the present research was to evaluate the regeneration effect of injectable-platelet rich fibrin (I-PRF) in lateral sinus lift.

Methods: A total of 46 cases, who lost their single posterior tooth with residual bone height of 3-5 mm, who needed lateral sinus lift, were treated in our hospital for implantation from June 2014 to Jun 2015. They were randomly divided into 2 groups.

[Clinical efficacy and effects of CAD/CAM zirconia all-ceramic crown and metal-ceramic crown restoration on periodontal tissues].

Purpose: To investigate the clinical efficacy and effects of CAD/CAM zirconia all-ceramic crown, cobalt-chromium alloy and silver-palladium alloy porcelain-fused-to-metal crown restorations on periodontal tissues.

Methods: Forty-nine teeth with crowns in 46 patients were randomly assigned into CAD/CAM zirconia all-ceramic crown group, cobalt-chromium alloy porcelain-fused-to-metal crown group and silver-palladium alloy porcelain-fused-to-metal crown group. The amounts of GCF, TNF-α and IL-6 were analyzed before and 12 months after restorations, and the clinical efficacy was evaluated.

[Cone-beam CT study of bone septa during maxillary sinus lift among Changzhou population].

Purpose: To observe the incidence, location, morphological characteristics of sinus septa among Changzhou population, and to investigate the relationship between maxillary posterior teeth loss and bony septum, and the guiding significance for sinus lift.

Methods: One hundred and twenty-four subjects were selected, the preoperative cone-beam CT (CBCT) data was analyzed by NNT software, which provided a three-dimensional measurement of the maxillary sinus septa. SPSS 13.

[Three dimensional measurement and analysis of maxillary protraction treatment in skeletal Class III malocclusion].

Purpose: To study the three-dimensional mechanism of maxillary protraction in skeletal Class III malocclusion by cone-beam CT (CBCT).

Methods: Fourteen patients (6 males and 8 females with a mean age of 10.9 years) of early permanent dentition with skeletal Class III malocclusion were treated with maxillary protraction.