[Efficacy of combined application of glycine powder air-polishing in non-surgical treatment of peri-implant diseases].

OBJECTIVE: To compare the clinical efficacy of combined application of glycine powder air-polishing and mechanical submucosal debridement in non-surgical treatment of peri-implant diseases. METHODS: A randomized controlled clinical study was carried out on patients diagnosed with peri-implant diseases in the Department of Periodontology, Peking University School and Hospital of Stomatology, between May of 2020 and June of 2021.Twenty-eight patients with totally sixty-two implants were enrolled.The patients were randomly divided into the test group and control group. The patients in the test group (13 subjects/32 implants) received mechanical submucosal debridement using titanium curettes combined with application of glycine powder air-polishing, while the control group (15 subjects/30 implants) received mechanical submucosal debridement using titanium only. Clinical parameters, such as plaque index (PLI), pocket probing depth (PPD), bleeding index (BI) and the percentage of suppuration on probing on implants' level (SoP%) were measured at baseline and 8 weeks after non-surgical intervention. Changes and group differences of clinical parameters of the implants before and 8 weeks after non-surgical intervention were compared. RESULTS: Mean PLI, PPD, BI of both the test group and control group significantly reduced 8 weeks after non-surgical intervention (P < 0.05). Compared with the control group, the test group achieved lower BI (2.7±0.8 vs. 2.2±0.7, P < 0.05), more reduction of BI (0.6±0.7 vs. 1.1±0.6, P < 0.01) and more reduction of SoP% (21.9% vs. 10%, P < 0.05) after non-surgical intervention. Both the control and test groups exhibited comparable PLI and PPD reductions (P>0.05). For the implants diagnosed with peri-implant mucositis, the test group revealed more signi-ficant reduction in BI and SoP% than the control group (1.0±0.7 vs. 0.4±0.7, P=0.02; 6.3% vs. 0, P=0.012). There was no significant difference existing in PLI and PD improvement between the control group and test group (P>0.05). For the implants diagnosed with peri-implantitis, there was no significant difference existing in PLI, PPD, BI and SoP% improvement values between the test and control groups (P>0.05). No complications or discomforts were reported during the study. CONCLUSION: Both treatment procedures could relieve the inflammation of peri-implant soft tissue. Non-surgical mechanical submucosal debridement combined application of glycine powder air-polishing is associated with significant reduction of soft tissue bleeding and suppuration on probing especially in the implants diagnosed with peri-implant mucositis.

[Gingival thickness assessment of gingival recession teeth].

OBJECTIVE: To evaluate the gingival thickness and gingival biotype of gingival recession teeth of Chinese population. METHODS: A total of 112 non-molar teeth with gingival recession in 34 patients were included. Direct measurement, cone-beam computerized tomography (CBCT) measurement and periodontal probe method were used to evaluate gingival thickness and biotype. Gingival thickness was measured at 2 mm apical to the gingival margin. Direct measurement was performed with a caliper of 0.01 mm resolution and anesthesia needles attached to silicone disk stops. Gingival biotype was assessed by sulcus probing, if the periodontal probe was visible through the gingival tissue, the gingival biotype was thin; If not visible, the gingival biotype was thick. The differences of gingival thickness among different gingival biotype, tooth site and gingival recession type were analyzed respectively. Besides, the results of CBCT measurement was analyzed compared with the direct measurement. RESULTS: The average gingival thickness of non-molar recession teeth was (1.17±0.41) mm. The average gingival thickness of thick and thin biotype group were (1.38±0.4) mm and (0.97±0.30) mm, respectively, with statistically significant difference (P<0.001). The median of gingival thickness was 1.1 mm. Using 1.1 mm as the cut-off value of thick and thin gingival thickness group, the results matched well with the gingival biotype classification results by periodontal probe method (P=1.000). The average gingival thickness of maxillary teeth was significantly thicker than that of the mandibular teeth. They were (1.39±3.44) mm and (1.01±0.31) mm, respectively (P<0.001). The mean gingival thickness of MillerI, II and III degree gingival recession teeth were (1.15±0.34) mm, (0.83±0.17) mm and (1.26±0.56) mm, respectively, without statistically significant difference (P=0.205). The gingival thickness measurement results between CBCT method and direct measurement were without statistically significant difference (P=0.206). CONCLUSION: In the non-molar gingival recession teeth, the cut-off value of gingival thickness to classify thick and thin biotype of Chinese population was 1.1 mm. The average gingival thickness of the maxillary teeth was significantly thicker than that of the mandibular teeth. Besides, CBCT measurement was an accuracy method for evaluating facial gingival thickness.

[Vestibular incision subperiosteal tunnel access with connective tissue graft for the treatment of Miller classI and II gingival recession].

OBJECTIVE: To evaluate the clinical outcomes of vestibular incision subperiosteal tunnel access (VISTA) with connective tissue graft (CTG) in the treatment of Miller classes I and II localized gingival recession. METHODS: Ten patients with 10 Miller classes I and II localized gingival recessions were enrolled in the study. All defects were equal to or above 2 mm in recession depth. All the patients received treatment with VISTA+CTG. Their clinical parameters, including recession depth (Rec), recession width (RW), keratinized tissue width (KT), clinical attachment loss (CAL), probing depth (PD) were recorded and compared before surgery and 6 months later. The mean root coverage (MRC) and complete root coverage (CRC) were calculated at the end of 6 months. A visual analogue scale (VAS) was used to estimate the patients' discomfort during the operation and during the 2 weeks post-operation. Patient-based aesthetic satisfaction 6 months after surgery was evaluated by a VAS. RESULTS: The mean Rec was (2.65±0.82) mm at baseline, and (0.35±0.58) mm after 6 months. The VISTA+CTG treatment resulted in an improvement of (2.30±0.98) mm in recession depth (P<0.001). MRC was 86.67%±21.94% and CRC reached 70% at the end of 6 months. KT increased (0.90±1.22) mm (P<0.05). Aesthetic satisfaction on the patients' level was 8.30 based on VAS (0=unsatisfied, 10=extremely satisfied). The patients' discomfort during the operation and 2 weeks post operation were 2.40 and 4.30 (0=no pain, 10=extreme pain). Furthermore, clinical outcomes showed no statistically significant difference between the gingival biotypes, and between the teeth positioned in maxillary and in mandibular. CONCLUSION: VISTA+CTG could be an effective treatment for Miller classes I and II localized gingival recession. Clinical outcomes indicated decrease in recession depth and width, and increase in width of keratinized tissue. Patients suffered little pain during the operation and 2 weeks post-operation of healing and accessed good aesthetic satisfaction. VISTA+CTG could be an option for the treatment of Miller classes I and II localized gingival recession.

[Clinical and epidemiological characteristics of 245 cases of influenza A (H3N2)].

Objective: To investigate the clinical and epidemiological characteristics of influenza A (H3N2) infected patients in Jinhua area, and therefore to improve the understanding of infection with H3N2 influenza virus. Methods: The pharynx swab specimens for pathogenic detection were collected from acute respiratory infection (ARI) cases in the fever clinic of the sentinel hospital in Jinhua area from 2014 to 2017. Descriptive statistics method was used to analyze the clinical features and pathogenics characteristics of the patients infected with H3N2 influenza virus. The t test or χ(2) test of independent samples were used for comparison between groups. Results: A total of 3 803 cases of acute respiratory infection (ARI) were reported in the sentinel hospital in Jinhua area from 2014 to 2017. Among them, 245 cases (6.4%) of H3N2 influenza were diagnosed, including 153 males (62.4%) and 92 females (37.6%), aged from 0.5 to 95 years, with an average age of (50.1+15.7) years. They were divided into 5 age groups, with 107 (43.7%) patients aged 60 years and older. The incidence of major diseases was 43.7%. There was no significant difference in the gender in different age groups (χ(2)=4.581, P=0.333). The seasonal peak of H3N2 influenza A virus infection was mainly in summer (In June-September), but was also seen in other months. In the 4 years from 2014 to 2017, there were a total of 4 peaks, which occurred in July-September, July-August, June-August, and June-August. The body temperature of most patients (73.1%) was between 38.0 and 38.9 ℃. The main positive signs of H3N2 influenza A virus infection were different degrees of pharyngeal hyperemia and tonsillar enlargement. Fever (>38 ℃), cough, dizziness, fatigue, sore throat, headache, chills, shortness of breath, runny nose, myalgia, expectoration, nasal congestion were the main symptoms of H3N2 cases. The proportion of abnormal X-ray/CT manifestations in H3N2 influenza A virus infection cases was lower than that of other influenza viruses. 89.8% of the patients were positive for H3N2 influenza A. The average lymphocyte count was (1.1±0.5) × 10(9)/L, total platelet count (157±39) × 10(9)/L in H3N2 influenza A infection group, which were lower than those in other influenza positive patients [(1.2±0.6)×10(9)/L and (165±42) × 10(9)/L], while the neutrophil count (3.6±0.8) × 10(9)/L was higher than that in other influenza positive patients (3.4±1.0) × 10(9)/L(all P<0.05). Conclusions: Patients with H3N2 influenza A in Jinhua mostly presented with throat congestion and tonsillar enlargement in varying degrees, fever (>38 ℃), cough and sputum production. The seasonal peak of influenza A was in summer (June-September). Elderly aged 60 years or older were the susceptible group.

[Exploration and practice of Peking University Model to improve the clinical teaching effect of clinical postgraduates majoring in periodontology].

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.

[Exploration and practice of periodontal specialist training system].

The standardized training of specialist doctors is an important part of medical education after graduation and it is the only way to train clinicians to diagnose and treat the specialist diseases independently by using a standardized and high-quality way. The prevalence of periodontal disease and the proportion of patienets with severe and advanced periodontitis in our country are high and the diagnosis and treatment process for the periodontal disease are complicated. There is an urgent need to expand the team of periodontal specialists capable of the specialized treatment. The training of periodontal specialists in our country has just started. The present article summarizes the exploration and practice of periodontal specialist training in Peking University School and Hospital of Stomatology in the past five years, including the establishment of training bases, formulation of clear training goals, strict implementation of training rules, strengthening of process quality control to ensure the trainees could reach the expected standard of periodontal specialist after training. Through the summary of the previous stage practice, the authors hope to explore and establish a periodontal specialist training system in line with our country's national conditions and further to promote and accelerate the pace of nationwide periodontal specialist training system.

[Enhancing the clinical competence of postgraduate students in periodontology: design and implementation of multidisciplinary grand rounds].

Recently the model of cultivating stomatology talents for postgraduate education in China is primarily specialized education. The aim of the present study was to construct a multidisciplinary grand rounds series based on presentation and commentary for diagnosis and treatment plan of clinical cases, in order to improve the clinical competence of postgraduate students from various dental disciplines for resolving the clinical problems. The grand rounds series was designed for postgraduate students of periodontology, with the combination of the advantages of the international dentistry education experience and Chinese characteristics. This study focused on designing and exploring the multidisciplinary grand rounds series based on complicated periodontal clinical cases, and also on analyzing and evaluating the effectiveness of the series by questionnaire investigation for both teachers and students. The results of the preliminary investigation showed that postgraduate students had positive view on the form and content of the teaching rounds. However, more analysis is needed for further evaluation.

[Comparison of two training protocols in periodontal surgery teaching for undergraduate students].

Objective: To compare the efficacies of two training protocols, i.e. the multimedia instruction and the conventional method, in periodontal surgery teaching for undergraduate students. Methods: One hundred and twenty-three dental undergraduates in their pre-clinical training course were recruited and divided into two groups according to the learning grade matching principle: the experimental group (multimedia instruction, 60 students) and the control group (conventional method, 63 students). The teaching aim was to train the students gingivectomy and periodontal flap surgery by using the pig jaws. The conventional teaching method of teacher-demonstrating and student-practicing was used in the control group, and the practice time of the students' for each surgery was 45 minutes. A standardized teaching video combined with the teachers' explanations of the key steps was used in the experimental group. The students' practice time for each surgery was 60 minutes. The efficacy of teaching protocol was evaluated by the teachers according to the scoring criteria set by the teaching group. Results: In gingivectomy training, accuracy of fixed points, angle of postoperative gingival margin and morphology of gingiva of the experimental group were better than those of the control group. The experimental group also had more complete and continuous excised gingivae and more thorough adjacent gingival removal. The total scores of the experimental group were significantly higher than those of the control group (92.8±2.6 vs. 89.9±3.7, P<0.05). In periodontal flap surgery training, the experimental group operated the blade around the shape of the tooth better in internal bevel incision than the control group. Additionally, the incision position of internal bevel incision, periosteal integrity after flapping and flap depth of the experimental group were better than those of the control group. Besides, the experimental group had smoother flap edge and more thorough debridement. The total scores of the experimental group were significantly higher than those of the control group (92.2±4.1 vs. 89.2±4.4, P<0.05). Conclusions: The teaching efficacy of multimedia instruction was better than that of the conventional method. Its value needs to be further tested in future teaching practice.