Denture wearers' recognition for their oral health status, denture cleansing methods, and insurance health system / 대한치과보철학회지

PURPOSE: The aim of the present investigation was to understand the incidence, prevalence of denture stomatitis in denture wearers, who were over 60 years old, and use the results for a fundamental data to promote public awareness about denture stomatitis and its education tools. MATERIALS AND METHODS: From August 21 to September 8 2017, 500 denture wearers, who were more than 60 years old in Seoul and 4 other metropolitan cities (Busan, Daegu, Gwangju, and Daejeon), received questionnaires. The questionnaires included denture wearers' demographic distributions, specific dental treatment experiences, discomforts with current dentures, their oral health conditions, and the method of denture cleansing. RESULTS: Thirty-two percent of 500 denture wearers responded that they have healthy oral conditions. Two hundred and eight respondents (41.6%) were aware of denture stomatitis. Only 131 (26.2%) were informed about the removable denture covered by national health insurance and 327 (65.4%) of denture wearers were using the improper denture cleansing methods. CONCLUSION: A large number of denture wearers still do not recognize the importance of proper treatment for denture stomatitis, insurance covered denture treatments, and adequate denture cleansing methods.

Effect of bone-implant contact pattern on bone strain distribution: finite element method study / 대한치과보철학회지

PURPOSE: To date most of finite element analysis assumed the presence of 100% contact between bone and implant, which is inconsistent with clinical reality. In human retrieval study bone-implant contact (BIC) ratio ranged from 20 to 80%. The objective of this study was to explore the influence of bone-implant contact pattern on bone of the interface using nonlinear 3-dimensional finite element analysis. MATERIALS AND METHODS: A computer tomography-based finite element models with two types of implant (Mark III Branemark(R), Inplant(R)) which placed in the maxillary 2nd premolar area were constructed. Two different degrees of bone-implant contact ratio (40, 70%) each implant design were simulated. 5 finite element models were constructed each bone-implant contact ratio and implant design, and sum of models was 40. The position of bone-implant contact was determined according to random shuffle method. Elements of bone-implant contact in group W (wholly randomized osseointegration) was randomly selected in terms of total implant length including cortical and cancellous bone, while ones in group S (segmentally randomized osseointegration) was randomly selected each 0.75 mm vertically and horizontally. RESULTS: Maximum von Mises strain between group W and group S was not significantly different regardless of bone-implant contact ratio and implant design (P=.939). Peak von Mises strain of 40% BIC was significantly lower than one of 70% BIC (P=.007). There was no significant difference between Mark III Branemark(R) and Inplant(R) in 40% BIC, while average of peak von Mises strain for Inplant(R) was significantly lower (4886 +/- 1034 microm/m) compared with MK III Branemark(R) (7134 +/- 1232 microm/m) in BIC 70% (P<.0001). CONCLUSION: Assuming bone-implant contact in finite element method, whether the contact elements in bone were wholly randomly or segmentally randomly selected using random shuffle method, both methods could be effective to be no significant difference regardless of sample size.