ABSTRACT
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.
ABSTRACT
Objective@#To explore the training pattern of periodontal probing practice so as to improve the accuracy of probing depth measurements of undergraduate students.@*Methods@#Sixty-two undergraduate dental students in their pre-clinical training course were divided into two groups (31 students in each group): the reform group and the control group. The students in reform group learned and practiced periodontal probing by using transparent gingiva models for 30 minutes, and using conventional periodontal probing models for further 90 minutes in two sessions. The total practicing time was 2 hours. The students in control group learned and practiced periodontal probing using conventional periodontal probing models only for 1 hour of practicing time. After the training, new conventional periodontal probing models were used to evaluate the accuracy of probing depth measurements of the students in the two groups. The probing depths of Ramfjord index teeth were recorded by the students and were compared with the results of an experienced teacher's measurements.@*Results@#The percentage of absolutely consistent sites in the reform group (63.4% [708/1 116]) was significantly higher than that of the control group (60.0% [670/1 116]) (P=0.012). In both reform group and control group, the percentages of absolutely consistent sites of the incisors (reform group: 69.1% [257/372], control group: 65.9% [245/372]) were significantly higher than those of the molars (reform group 58.9% [219/372], control group 54.3% [202/372])(P< 0.01), meanwhile, the percentages of absolutely consistent sites of the buccal-lingual sites (reform group: 88.7% [330/372], control group: 80.4% [299/372]) were significantly higher than those of the interproximal sites (reform group: 50.8% [378/744], control group: 49.9% [371/744])(P<0.01).@*Conclusions@#The comprehensive reform of periodontal probing training could improve the accuracy of probing depth measurement of the undergraduate students. During the pre-clinical practice, probing training in the molar areas and the interproximal sites should be reinforced.
ABSTRACT
Objective:To establish a stable primary culture method of human gingival epithelial cells, with a higher successful rate and shorter culture time.Methods:Nine patients who received “crown-lengthening surgery”with relatively healthy periodontal conditions were selected (n =9).Gingival sam-ples were collected from the 9 donors during gingivectomy.Gingival epithelial cells were isolated and cul-tured by both an advanced enzyme digestion method and a tissue explant method.In the advanced enzyme digestion culture process,2.5 g/L DispaseⅡwas used to separate the epithelial tissue part from the con-nective tissue part,which lasted for one night.Then the epithelial tissues were digested by 0.025% tryp-sin without EDTA for 10 minutes,and centrifuged by keeping the digested epithelial tissues that re-mained.This advanced method not only decreased the concentration and digesting time of the two above-mentioned enzymes,but also simplified the centrifugel process.The tissue explant method was not changed too much compared with the original method.Growing processes of the primary cells cultured by the two methods were observed and recorded respectively,and indirect immunocytochemical staining was used to identify the type of cultured cells.At the same time,successful rates and cell culture time were also compared between the two methods.Results:Human gingival epithelial cells with typical morpholo-gy could be cultured within a shorter period by the advanced enzyme digestion method with a successful rate of 88.9%,and proliferated rapidly as sheets.After 10 -14 d cells could be passaged,gradually turned to be like fibroblasts when passaged to the third generation,and eventually went to apoptosis.The primary culture time was longer by using the tissue explant method,and approximately after 17 -22 d cells could be passaged,although the successful rate was the same as the enzyme digestion method.Cy-tokeratin staining was both positive by indirect immunocytochemical staining of cells.Conclusion:Pri-mary human gingival epithelial cells cultured by the advanced enzyme digestion method could grow faster and be passaged to the second generation successfully,which could supply a stable origin for cellular ex-periments.