Developing a Competency-based Dental Curriculum in Korea

Ji, Young-A,Lee, Jaeil,Baek, Seungho The Korean Dental Association 2019 대한치과의사협회지 Vol.57 No.8

Purpose: In recent years, efforts to improve the dental curriculum in South Korea have focused on a shift to outcome-based dental education based on core competencies in dentistry. So far, the field has seen various studies on the development of competencies, performance evaluation, and the importance of outcome-based education, but few studies have documented the development of such an education model. Therefore, this study develops an OBE curriculum for dentistry education and describes the development procedures and then finally this study intends to share our experience to other dental schools. Methods: This study introduces the development procedure and details of an outcome-based education model for dental education and presents the five stages of an outcome-based education model. In this study, 3 educational experts and 2 dental professor composed the TFT and developed the research method according to the ADDIE model. Step 1 is to conduct quantitative / qualitative research analysis through some survey and interview, Step 2 is to do a survey to revise competency, Step 3 is to develop a materials through consensus and participation of our professors of the dental school, Step 4 is to do some workshops, Step 5 is to prepare and conduct a outcome evaluation. Results: Step 1 is a required process for developing an educational model: the Job Analysis & Need Analysis stage. Step 2 is the Development of Outcome and Competency stage, which involves revising the competencies that are the basis of the curriculum. Step 3 is developing competency descriptions, competency levels, and evaluation criteria?the Development of Outcomes and Evaluation Standards. Step 4 is the Development of Milestones for Curriculum and Instructional Strategy, which examines the curriculum's problems and analyzes the improvements of each course. Step 5 is the Evaluating Outcomes stage, conducted based on the competencies specified by the target dental school. Conclustion: The model presented here can serve as a foundation for outcome-based education in other dental schools.

Clinical effect of calcium chelating and deproteinizing agent containing dental conditioning gel on alleviation of periimplant mucosa inflammation

Yang, Kwang-Heon,Lee, Jue-Yeon,Jung, Jin-Hyung,Shin, Hyun-Seung,Cho, In-Woo The Korean Dental Association 2015 대한치과의사협회지 Vol.53 No.9

Purpose : The purpose of this clinical study was to evaluate the effect of chelating and deproteinizing agent containing dental conditioning gel on alleviation of peri-implant mucosa inflammation. Methods: 36 patients with functionally loaded implants for at least 1 year and have clinical signs of peri-implant mucositis were recruited. At baseline, all implants received subgingival prophylaxis with ultrasonic scaler. In the test group, patients were provided a chelating and deproteinizing agent dental conditioning gel (Clinplant$^{(R)}$) and were given instructions to applicate it around the implants using an interdental brush for 2 weeks. Chlorhexidine and saline were provided to the positive control group and negative control group, respectively. The modified sulcus bleeding index (mSBI), modified plaque index (mPI), and probing pocket depth (PPD) were evaluated at baseline, 1 week, and 2 weeks. Results: In the Clinplant$^{(R)}$ and chlorhexidine group, mSBI (-0.81, -0.85 respectively; p<0.01), mPI (-0.46, -0.5 respectively; p<0.01), and PPD (-0.58, -0.48 respectively; p<0.01) at 2 weeks were significantly reduced from baseline. In the saline group, all the clinical parameters were reduced but there was no statistical significance. The saline may be attributed to the influence of prophylaxis at baseline. Conclusions: The present study demonstrated the beneficial clinical effects of chelating and deproteinizing agent containing dental conditioning gel to decrease peri-implant mucosa inflammation equivalent to chlorhexidine. This dental conditioning gel might be useful for alleviation of peri-implant mucosa inflammation.

The effects of ascorbic acid on the morphology and cell proliferation of three-dimensional stem cell spheroids

이현진,여성일,박준범,Lee, Hyunjin,Yeo, Seong-Il,Park, Jun-Beom The Korean Dental Association 2017 대한치과의사협회지 Vol.55 No.9

Purpose: The effects of various concentrations of ascorbic acid on stem cell spheroids derived from intraoral areas are not known yet. Thus, the purpose of this study is to evaluate the effects of different concentrations of ascorbic acid on the morphology and cellular viability of stem cell spheroids derived from the gingival tissues. Materials and Methods: Stem cells were plated onto silicon elastomer-based concave microwells and grown in the presence of ascorbic acid at concentrations ranging from 0.003% to 0.3%. The morphology of the cells was viewed under an inverted microscope at day 1, 2, 3 and 5. Qualitative live/dead assay and quantitative cellular viability using Cell Counting Kit-8 were performed on day 2 and day 5. Results: Gingiva-derived stem cells formed spheroids irrespective of ascorbic acid concentration in silicon elastomer-based concave microwells. Increase in the diameter of spheroid were seen with higher concentrations of ascorbic acid. Higher cellular viability was seen in higher concentrations of ascorbic acid. Conclusion: Within the experimental setting, the application of ascorbic acid on stem-cell spheroids produced an increase in the size and higher viability with higher dosage. It can be suggested ascorbic acid be applied with stem cell spheroids for tissue engineering purposes.

Combined effects of a chemically cross-linked porcine collagen membrane and highly soluble biphasic calcium phosphate on localized bone regeneration

Kim, You-Kyoung,An, Yin-Zhe,Cha, Jae-Kook,Lee, Jung-Seok,Jung, Ui-Won,Choi, Seong-Ho The Korean Dental Association 2018 대한치과의사협회지 Vol.56 No.12

Objectives: Aim of this study was to evaluate bone regenerative efficacy of a chemically cross-linked porcine collagen membrane (CM) when used in combination with highly soluble biphasic calcium phosphate (BCP). Materials and methods: Physiochemical properties of the experimental collagen membrane were analyzed. Four circumferential defects with diameter of 8 mm were created in each calvarium of New Zealand white rabbits (n = 10). Defects were randomly allocated to one of following 4 groups: 1) BCP-CM (BCP (20% hydroxyapatite/80% ${\beta}$-tricalcium phosphate) covered with the prepared collagen membrane), 2) BCP (only BCP used), 3) CM (only the prepared collagen membrane used), and 4) C (control; only blood clot). After 2 weeks (n = 5) and 8 weeks (n = 5), histologic and histomorphometric analyses were performed. Results: The experimental collagen membrane exhibited dense and compact structure, relatively high tensile strength and lower degradability. Histologic analyses revealed that new bone increased rapidly at 2 weeks, while defect was preserved at 8 weeks. Histomorphometric analyses revealed that the new bone areas increased in the BCP-grafted groups over 8 weeks, with BCP-CM exhibiting greater total augmented area than that of BCP group both at 2 weeks ($27.12{\pm}3.99$ versus $21.97{\pm}2.27mm^2$) and 8 weeks ($25.75{\pm}1.82$ versus $22.48{\pm}1.10mm^2$) (P < 0.05). Conclusions: The experimental collagen membrane successfully preserved localized defect for 8 weeks despite early rapid resorption of BCP. Within the study limitations, combined use of the chemically cross-linked porcine collagen membrane and highly soluble BCP aided localized bone regeneration.

ORIGINAL ARTICLE - Adhesion of Streptococcus mutans and Streptococcus sobrinus to different types of self-ligating brackets

Yang, Pil-Seung,Yu, Yoon-Jeong,Cha, Jung-Yul,Hwang, Chung-Ju The Korean Dental Association 2012 대한치과의사협회지 Vol.50 No.7

Objective: The adhesion capabilities of different types of self-ligating brackets were measured with respect to Streptococcus mutans and Streptococcus sobrinus. Methods: Five types of self-ligating brackets (Clippy-C; Mini Clippy; Clarity-SL; Speed; Damon 3) were used for the experiment group and composite resin brackets (Spirit-MB), metal brackets (Victory) and polycrystalline alumina brackets (Clarity) were used for the control group. In order to assess adhesion of bacteria to the brackets, the brackets were cultured for 3, 6 and 24 hours in media containing bacteria and 20% sucrose. Results: There was no statistic difference in adhesion amount of Streptococcus mutans and Streptococcus sobrinus according to the types of brackets. A total adhesion amount according to bracket type was different. An extended incubation time increased adhesion amount. Observation under scanning electron microscope showed that Streptococcus sobrinus adhered more to Clippy-C and Victory rather than to Clarity-SL. Conclusions: Clarity-SL, a self-ligating esthetic bracket was confirmed to show lower bacterial adhesion to cariogenic bacteria, Streptococcus mutans and Streptococcus sobrinus group than other self-ligating brackets or conventional brackets, which suggests that proper use of self-ligating esthetic brackets might even be better in preventing tooth surface decalcification.

Removal of superficial dentin surface to restore decreased bond strength caused by sodium hypochlorite

Song, Mi-Yeon,Hwang, Ho-Keel,Jo, Hyoung-Hoon The Korean Dental Association 2015 대한치과의사협회지 Vol.53 No.12

Objective: Sodium hypochlorite (NaOCl) decreases the bond strength of resin composite. The purpose of this study was to compare the effect of antioxidant and superficial dentin surface removal on the microtensile bond strength of NaOCl-treated dentin. Materials and Methods: Twenty non-carious human third molars were used in this study. The dentin surfaces were treated with 5.25% NaOCl for 10 min, followed either by treatment with 10% ascorbic acid or superficial dentin surface removal. Two-step self-etch adhesive and resin composite were used for restoration. The bonded specimens were subjected to the microtensile bond strength test. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey's test (p < 0.05). Results: The bond strength after removal of the superficial dentin surface following NaOCl irrigation was similar to that in the control group. The group treated with 10% ascorbic acid demonstrated significantly higher bond strength than the other groups. Conclusion: NaOCl irrigation-induced reduction in dentin bond strength could be recovered by either treatment with 10% ascorbic acid or simple removal of the superficial dentin surface.

Comparative study of prosthetic complications associated with the bar-clip, milled bar, and Locator attachments for implant overdentures: a retrospective study

Yoon, Kye-Won,Heo, Ji-Ye,Hwang, Hee-Sung,Kim, Chul-Hoon,Kim, Bok-Joo,Kim, Jung-Han The Korean Dental Association 2016 대한치과의사협회지 Vol.54 No.12

Purpose. The purpose of this study was to compare the type and frequency of prosthetic complications associated with attachment types for implant overdenture. Material and methods. In this retrospective study, 38 patients (mean age, 63.5 years) have been treated with implant overdentures from 2007 to 2014. Ten patients received a bar-clip attachment. Eleven patients had received a milled bar with Locator attachment. Seventeen patients had received a Locator attachment. The mean follow-up period was 36.9 months (range, 15-83 months). The type and frequency of prosthetic complications was recorded. The frequency was analyzed to determine the statistical difference among the 3 different attachments by using one-way ANOVA (${\alpha}=.05$) and Bonferroni post hoc method at a 5% level of significance. Results. The total number of prosthetic complications was higher in the bar-clip attachment (55 events) than in the milled bar with Locator attachment (39 events) and the Locator attachment (34 events). There were no statistically significant differences, and the most common prosthetic complication was the loss of retention. In the bar-clip attachment group, the average frequency of prosthetic complications was 3.0 events per prosthesis during the first year. In the milled bar with Locator attachment and Locator attachment groups, the average frequencies were 1.45 events and 2.35 events, respectively. Statistically significant differences were observed in the frequency of the complication. (p = .043) Conclusions. Compared to the bar-clip attachment, implant overdentures that use milled bars with the Locator attachment have a significantly lower incidence of prosthetic complications in the first year of follow-up after placement.

Comparison of the clinical results between endoscopically assisted transoral approach and retromandibular approach for surgical treatment of mandibular subcondyle fracture

Lee, Woo-Yul,Cho, Jin-Yong,Yang, Sung-Won The Korean Dental Association 2016 대한치과의사협회지 Vol.54 No.12

Purpose : Aim of this study is to describe and compare clinical results and complications epending on the surgical approaches for the mandibular subcondyle fracture Materials and methods : The patients who had been diagnosed as the mandibular subcondyle fracture and underwent open reduction and internal fixation from May 2009 to December 2014 were included. They were divided into two groups depending on the surgical approaches; endoscopically assisted transoral approach and retromandibular approach. Association between the preoperative fracture classification and post-operative results was reviewed depending on the surgical approaches. Results : The number of patients selected in this study was 33. Eighteen patients (male 7, female 11) underwent open reduction and internal fixation via retromandibular approach and fifteen patients (male 12, female 3) underwent open reduction and internal fixation via endoscopically assisted transoral approach. The mean age, follow up period, and operation time were $44.29{\pm}15.19years$, $9.97{\pm}7.82months$, and $161{\pm}89.44minutes$. Post-operative results were all "good" state in the retromandibular approach group regardless of the fracture classification but two patients in the endoscopically assisted transoral approach group underwent re-operation due to "poor" results. The fracture types of two were classified as displacement and lateral override at the same time. There was no statistically significant difference between two groups. Three patients in the retromandibular approach group had experienced facial nerve palsy (17%) temporarily. No one showed malocclusion in this study. There was no significant difference on the complications such as temporomandibular disorder, local infection, and condyle resorption depending on the surgical approaches. Conclusion : In this study, there was no significant difference on the complications between the two groups but retromandibular approach has advantage over endoscopically assisted transoral approach in case of the severely displaced subcondyle fracture.

A Study of mechanical properties of oxide layer removed Co-Cr-Mo abutments

Ryu, Jae-ho,Huh, Jung-Bo,Ro, Jung-Hoon,Yun, Mi-Jung,Jeong, Chang-Mo The Korean Dental Association 2015 대한치과의사협회지 Vol.53 No.11

PURPOSE: The aim of this study was to evaluate the influence of the oxide layer removal process in the Co-Cr-Mo (CCM) abutment after casting procedure on the prosthesis settlement and screw stability. MATERIALS AND METHODS: CCM abutments of four different interface conditions (CCM-M; machined, CCM-O; oxide layer formed, CCM-B; blasted, CCM-P; polished after blasted) and gold abutment (Gold-C; Cast with type III Gold alloy) were used. The initial settling values of abutments were evaluated according to the difference of implant-abutment length when the tightening torques were applied at 5 Ncm and 30 Ncm, and the settling values of abutments caused by loading were evaluated according to the difference of implant-abutment length before and after loading with 250 N, 100000 cycle. The loss ratios of removal torque for abutment screws were evaluated according to the difference in value of removal torques under 30 Ncm tightening torque applied before and after cyclic loading. RESULTS: The CCM-P and CCM-B group showed a higher initial settling value compared with the Gold-C group (P<.05), while the Gold-C group showed the highest settling values caused by loading (P<.05) and no significant differences were observed for between CCM groups (P>.05). The loss ratio of removal torque values for the CCM-B, CCM-P groups did not differ significantly from that of the Gold-C group (P>.05). CONCLUSION: Even though the oxide layer was removed by different methods, CCM abutment with internal conical connection structure showed lower abutment settling and similar screw loosening after cyclic loading compared with gold abutment.

A morphometric study on stainless steel crowns of the primary first molar using a three dimensional scanner

Lee, Jihyun,Shin, Teo Jeon,Kim, Young-Jae,Kim, Jung-Wook,Jang, Ki-Taeg,Lee, Sang-Hoon,Kim, Chong-Chul,Hyun, Hong-Keun The Korean Dental Association 2016 대한치과의사협회지 Vol.54 No.6

Objectives: The aim of this study was to assess the morphologic characteristics of two types of stainless steel crowns (SSCs) for the first primary molar using a 3D scanner. Study design: Two types of SSCs, KIDS CROWN (KC) and 3M ESPE ND-96 (ND), for the first primary molars were scanned using a 3D scanner. The mesiodistal and buccolingual diameters at the height of the contour and the cervical margin, occlusocervical diameters on the mesial, distal, buccal, and lingual aspects were measured, and the crown shape ratio, the smooth surface crown height ratio, and the cervical convergence were calculated. Results: In the crown shape ratio of the mandibular SSC, KC was larger buccolingually compared with ND. In the smooth surface crown height ratio, ND was larger than KC in all of the maxilla and mesial, distal, and lingual aspects of the mandible. ND was more convergent to the cervical mesiodistally and buccolingually compared with KC. Conclusion: In the superimposed images of the maxillary SSC, the mesiolingual and distolingual line angles of KC were more prominent compared with ND. In the mandible, ND demonstrated higher cusps and more obvious buccal developmental lobes than KC. ND showed a larger cervical undercut than KC.