Standardized multi-institutional data analysis of fixed and removable prosthesis: estimation of life expectancy with regards to variable risk factors

PURPOSE@#This study aims to assess and predict lifespan of dental prostheses using newly developed Korean Association of Prosthodontics (KAP) criteria through a large-scale, multi-institutional survey. @*MATERIALS AND METHODS@#Survey was conducted including 16 institutions. Cox proportional hazards model and principal component analysis (PCA) were used to find out relevant factors and predict life expectancy. @*RESULTS@#1,703 fixed and 815 removable prostheses data were collected and evaluated. Statistically significant factors in fixed prosthesis failure were plaque index and material type, with a median survival of 10 to 18 years and 14 to 20 years each. In removable prosthesis, factors were national health insurance coverage, antagonist type, and prosthesis type (complete or partial denture), with median survival of 10 to 13 years, 11 to 14 years, and 10 to 15 years each. For still-usable prostheses, PCA analysis predicted an additional 3 years in fixed and 4.8 years in removable prosthesis. @*CONCLUSION@#Life expectancy of a prosthesis differed significantly by factors mostly controllable either by dentist or a patient. Overall life expectancy was shown to be longer than previous research.

Prediction of lifespan and assessing risk factors of large-sample implant prostheses:a multicenter study

PURPOSE@#This study aimed to analyze factors influencing the success and failure of implant prostheses and to estimate the lifespan of prostheses using standardized evaluation criteria. An online survey platform was utilized to efficiently gather large samples from multiple institutions. @*MATERIALS AND METHODS@#During the one-year period, patients visiting 16 institutions were assessed using standardized evaluation criteria (KAP criteria). Data from these institutions were collected through an online platform, and various statistical analyses were conducted. Risk factors were assessed using both the Cox proportional hazard model and Cox regression analysis. Survival analysis was conducted using Kaplan-Meier analysis and nomogram, and lifespan prediction was performed using principal component analysis. @*RESULTS@#The number of patients involved in this study was 485, with a total of 841 prostheses evaluated. The median survival was estimated to be 16 years with a 95% confidence interval. Factors found to be significantly associated with implant prosthesis failure, characterized by higher hazard ratios, included the ‘type of clinic’, ‘type of antagonist’, and ‘plaque index’. The lifespan of implant prostheses that did not fail was estimated to exceed the projected lifespan by approximately 1.34 years. @*CONCLUSION@#To ensure the success of implant prostheses, maintaining good oral hygiene is crucial. The estimated lifespan of implant prostheses is often underestimated by approximately 1.34 years. Furthermore, standardized form, online platform, and visualization tool, such as nomogram, can be effectively utilized in future follow-up studies.

Full mouth rehabilitation of mandibular edentulous patient using implant hybrid prosthesis / 대한치과보철학회지

In edentulous patients, the advantages of prosthodontic therapy using oral implants include both stability and comfort. Advantages suggested for this approach include the prevention of mandibular bone resorption and increased masticatory function. Implant hybrid prostheses place 4 to 6 implants between the mental foramens, and cantilevers are used to replace the posterior teeth at both ends. The 85

Clinical study on the comparison of gold and zirconia wear in an implant-supported fixed prosthesis

PURPOSE: The purpose of this study was to compare and analyze the wear of a prosthesis for 6 months after restoration with implant-supported fixed dental prosthesis made of either zirconia or gold. MATERIALS AND METHODS: This study was conducted on patients requiring implant-supported fixed dental prostheses on first or second molar from January, 2015 to January, 2016. A total of 47 prostheses and antagonists were examined. Occlusal surface was recorded by impression of each prosthesis and antagonist 1 week and 6 months after prosthesis delivery. The digital files were created by impression scan. Occlusal shapes of 1 week and 6 months were compared and wear of prostheses and antagonists was analyzed. The Mann-Whitney test was used to analyzed the result data underwent normality test using SPSS (Version 23.0, IBM Corporation) RESULTS: Mann-Whitney test revealed that there was no statistically significant difference in the median amount of mean vertical wear for 6 months in zirconia (50.84 μm) and gold (42.84 μm) prostheses (P > 0.05). When the opposing teeth were natural, the median amount of mean vertical wear of zirconia and gold prostheses was 47.72 μm and 41.97 μm, respectively, and the median amount of mean vertical wear of enamel was 47.26 μm and 44.59 μm, respectively. Statistical analysis showed no significant difference (P > 0.05). CONCLUSION: Despite the short study period and the small number of experimental groups, zirconia and gold showed no significant difference in wear during the first 6 months. Opposing natural enamel also showed no significant difference in the wear.

The use of surgical guide stent for implant placement / 대한치과보철학회지

Surgical guide not only provide diagnosis and treatment plan, but even location and direction of implantation. Surgical guide could be divided into non-limited design, partially limited design, and completely limited design. Partially limited design is easily manufactured and inexpensive but less accuracy, compared to completely limited design. From this approach, partially limited design may be particularly effective in patients who present with a single missing tooth or partially edentulous teeth. Completely limited design is anatomically accuracy, esthetical and functional, optimized treatment for prosthetic and biomechanical perspective, and also minimizes discomfort for post-treatment. The purpose of this study is to review previous studies of various surgical guides and applying in clinic.

Prosthetic rehabilitation for a glossectomy patient: a clinical report / 대한치과보철학회지

Malignant tumours of the oral cavity that require resection of the tongue result in severe deficiencies in speech and deglutition. In such patients, improvements in mastication, swallowing, and speech may be reasonable goals for treatment. The viability of a prosthodontic approach to treatment depends on the type and extent of surgery. In a total glossectomy, a mandibular tongue prosthesis is the treatment of choice. Mandibular tongue prosthesis occupies the space in the floor of the oral cavity. It provides the patients with a platform for directing food into the esophagus and aids in speaking. This type of prosthesis can achieve that protection of the underlying fragile tissue and improvement in appearance and psychosocial adjustment. This case report describes the technical steps involved in prosthetic rehabilitation for a glossectomy patient.

Comparison of microleakage after load cycling for nanofilled composite resin fillings with or without flowable resin lining / 대한치과보철학회지

STATEMENT OF PROBLEM: when using resin for class II restoration, micoleakage by instrumentation can be regarded as the primary negative characteristic. A review of the available literature suggests that using flowable resin as liner to decreased microleakage. PURPOSE: The aim of this study was to determine the influence of the nanofilled flowable resin lining on marginal microleakage after load cycling in class II composite restoration fillings using nanofiller resin. MATERIAL AND METHODS: 24 extracted premolars were prepared with class II cavity. F group was restored the nanofilled resin with the nanofilled flowable resin as liner. NF group was restored the nanofilled resin only. After restoration, an experiment was performed on 2 groups using a 300N load at 104, 105 and 106 cycles. Prior to and before each load cycling, it was gauged length on total marginal microleakage, axial marginal microleakage and buccal, gingival, lingual marginal microleakage. Data were analyzed with the Mann-Whitney test & Kruskal-Wallis test. RESULTS: There were statistically significant differences between 2 groups and between individual groups. (P < .05) The result showed less microleakage in teeth restored by the nanofilled resin, which was lined by the nanofilled flowable resin. CONCLUSION: There was significant reduction in microleakage when the nanofilled flowable resin lining was placed underneath the nanofilled resin in class II composite restoration fillings.