• Journal of Technologic Dentistry
• /
• v.28 no.2
• /
• pp.347-353
• /
• 2006

The Purpose of this study was to compare the distribution of implant fixtures according to length and diameter between screw-retained and cement-retained implant-supported fixed prosthesis and to asses whether prosthesis retained types affected the selection of size of implant fixtures. This study presents a follow-up 2,416 implant-supported fixed type prosthesis that have been screw retained or cemented retained for about 10 years in 14 dental clinics. Included in the study were 458 men and 397 women and implant fixtures used in this study were screw retained type 1,057 and 1,359 of cemented retained type. The statistical results among the diameter types of fixture by prosthesis retained type was no significant difference noted (P= 0.809) and there was significant differences was enough to among the lengths of fixture by prosthesis retained type (P= 0.020). However there were no significant difference among the fixture diameter types and length by prosthesis retained type (P= 0.486). So there was not affected to prostheis fixation mechanism for the size of implant fixtures.

• The Journal of Advanced Prosthodontics
• /
• v.16 no.2
• /
• pp.67-76
• /
• 2024

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.

• The Journal of Korean Academy of Prosthodontics
• /
• v.44 no.2
• /
• pp.174-184
• /
• 2006

Purpose: Current trend in implant dentistry is changing from external connection to internal connection. To evaluate the splinting of external and internal connection implant on screw loosening, 2-units prosthesis was fabricated with BioPlant $System^(R)$ of external connection type and Lifecore STAGE-1 Single Stage Implant $System^(R)$ of internal connection type. Material and Method: Experimental group is classified into three groups. 1) $G_1-EE$: 2-units prosthesis was fabricated with two Bioplant $System^(R)$ of external connection type. 2) $G_1-EI$: 2-units prosthesis was fabricated with one BioPlant $System^(R)$ of external connection type and one Lifecore STAGE-1 Single Stage Implant $System^(R)$ of internal connection type. 3) $G_1-II$: 2-units prosthesis was fabricated with two Lifecore STAGE-1 Single Stage Implant $System^(R)$ of internal connection type. In fabricating 2-units prosthesis, two hexed abutments are recommended when two implants are installed parallel, otherwise one hexed abutment is used on major occlusal force area and one nonhexed abutment is used on the other area. Since it is rare to find two implants being parallel, it is hard to fabricate prosthesis with passive adaptation using two hexed abutments. It is much more difficult to acquire passive adaptation when using hex abutment compared to nonhex abutment. To evaluate the influence of hexed and nonhexed abutment on screw loosening, 2-units prosthesis was fabricated with hexed and nonhexed abutment. Experimental group is classified into three groups. 1) $G_2-HH$: 2-units prosthesis was fabricated with two hexed abutments. 2) $G_2-HN$: 2-units prosthesis was fabricated with one hexed abutment and one nonhexed abutment. 3) $G_2-NN$: 2-units prosthesis was fabricated with two nonhexed abutments. Result: The results of comparing the detorque value after loading on a each prosthesis periodically are as follows. 1. In splinting group of external and internal connection implant, $G_1-II$ group demonstrated the biggest detorque value, followed by $G_1-EI$ group and $G_1-EE$ group. 2. There is no notable significance between external connection implant of $G_1-EI$ group and $G_1-EE$ group and also no significance between internal connection implant of $G_1-EI$ group and $G_1-II$ group. 3. $G_2-HH$ group showed higher detorque value than $G_2-HN\;and\;G_2-NN$ group. From the results, we can concluded that using both external connection and internal connection implant together is clinically acceptable and in order to acquire a good passive adaptation in fabricating 2-units implant prosthesis we can use two nonhexed abutments.

• The Journal of Advanced Prosthodontics
• /
• v.6 no.6
• /
• pp.474-482
• /
• 2014

PURPOSE. To assess removable prosthetic restoration tolerance according to the patient section of the short form of the Gagging Problem Assessment Questionnaire (GPA-pa SF) and the influence of gender, education level and prosthesis type and denture-related mucosal irritation on the GPA-pa SF scores before treatment and over a period of two months after prosthesis insertion. MATERIALS AND METHODS. 130 participants who required removable prosthesis were surveyed with a standard form that included questions regarding age, gender, education level, dental attendance, and prosthetic restoration type. Participants answered the GPA-pa SF before restoration (T0) and 1 day (T1), 2 days (T2), 15 days (T3), 1 month (T4), and 2 months (T5) after prosthesis insertion. RESULTS. Of the 130 participants, 110 participants completed the prosthetic restoration procedure, but only 93 of these were able to use the prosthesis over the two-month period. The mean GPA-pa SF score obtained at T0 was higher than the scores obtained at the other periods in the total of the sample. Significant difference was present between mean scores obtained at T0-T1 and T2-T3 than scores obtained at other periods (P<.05). Female participants and participants with denture-related mucosal irritation had higher GPA-pa SF scores at all time points analysed. Significant difference was present between mean GPA-pa SF scores obtained at T2-T3 than scores obtained at other periods for females and participants with denture-related mucosal irritation (P<.05). Education level and prosthesis type did not significantly influence the GPA-pa SF score at any time point analysed (P>.05). CONCLUSION. GPA-pa SF scores were higher before the restoration procedure began, and decreased over time with the use of prosthesis. Gender and denture-related mucosal irritation affected the GPA-pa SF scores.

• Journal of Korean society of Dental Hygiene
• /
• v.7 no.1
• /
• pp.15-30
• /
• 2007

The main objective of this study is to investigate the improvement of the quality of dental health based on the dental service satisfaction factors of the old dental prosthesis patients of more than 60 years of age who use the dental institutes including dental hospital, clinic, and public health center and to identify the interest in the dental prosthesis as changing paint. Across the country through a questionnaire survey of a question and answer type conducted by the trained dental hygienists or dentist's. Major results of the empirical analysis are as follows. 1. looking at variation of the variables of socio-demographic features of the respondents, the group of female, age distribution of 60-65, average monthly income of 0.5-1 million Won, and schooling background of college showed significant difference. And the prosthesis treatment in terms of the purpose of isiting a dental institute, and the dental clinic in terms of the type of visiting dental institute showed a remarkably significant difference. 2. looking at variation of variables of the general features of the respondents, a prosthesis satisfaction service in terms of age showed significant difference: a prosthesis satisfaction service, dental staffs' service and dental facilities' service in terms of average monthly income showed significant difference: the entire conditions except for the dental facilities' service in terms of schooling and general features showed significant difference: and in terms of the purpose of visiting dental institute, it showed no significant difference. In terms of a visiting dental institute, the prosthesis satisfaction service, dental facilities, overall level of satisfaction, result of treatment, word of mouth and revisit showed significant difference. 3. looking at variation of the variables of post-installation prosthesis satisfaction of the respondents, the prosthesis satisfaction service, dentist's dental service, staffs' service, dental facilities' service and revisit in terms of the prosthesis type: and the prosthesis satisfaction service, word of mouth, revisit and overall level of satisfaction from the perspective of serious concern showed significant difference. The prosthesis satisfaction service and dentist's service in terms of the solving the economic burden: and the entire variables in terms of dissatisfaction elements showed a similar level of significant difference 4. in regard to the satisfaction of dental service and the change of the recognition of prosthesis patients, it was revealed that the level of dental prosthesis satisfaction of the respondents was closely related to the dentist's service, staffs' service, and dental facilities' service. Finally, looking at the influence of the dental service on the treatment result, satisfaction, word of mouth, revisit and the overall satisfaction level, it was revealed that they had a great impact on the prosthesis satisfaction service.

• Journal of Korean Dental Science
• /
• v.15 no.1
• /
• pp.84-91
• /
• 2022

An all-on-4 restoration allows edentulous patients to use a fixed prosthesis with a minimum number of implants. These implant-supported fixed complete dentures have traditionally been fabricated as screw-retained or cement-retained prostheses. However, it is difficult to passively fit the long-span full-arch prosthesis using the screw-retained type restoration, and predictable retrievability is not obtained with the cement-retained type. This case report describes a prosthesis fabricated using a combination of the two retention types. The screwmentable method allows the implant-supported fixed complete denture to achieve a passive fit at the connection with retrievability. In addition, a framework with an optimized size was designed by using digital dental technology.

• The Journal of Korean Academy of Prosthodontics
• /
• v.55 no.4
• /
• pp.427-435
• /
• 2017

The most important factor in the treatment of fully edentulous patients using implants is the shape of the definitive prosthesis. After the shape of the definitive prosthesis is determined, residual bone analysis and selection of the implant type, number and position should be followed. In this case, for restoration of an edentulous patient fully implanted (except the maxillary right lateral incisor) without considering definitive prosthesis, facial esthetics and possibility of fixed type prosthesis were evaluated using complete denture. It was determined that the fixed type prosthesis was possible. Implants that could not be used for the definitive prosthesis were excluded from the treatment plan and fixed type provisional restorations were fabricated. After four months of provisional restorations, the patient showed stable occlusion and esthetic satisfaction. Definitive prosthesis was made of zirconia using CAD/CAM (computer aided design and computer aided manufacturing). The results were satisfactory during the 3 months of follow-up period after termination of treatment.

• Journal of Technologic Dentistry
• /
• v.35 no.1
• /
• pp.1-17
• /
• 2013

Purpose: This study was to assess the extents of the release of metals from the non-precious alloys used for dental casting by measuring the differences in the extents of the release of metals by types of alloys, pH level and elapsed time. Methods: Uniform-sized specimens(10 each) were prepared according to the Medical Device Standard of the Korea Food and Drug Administration(2010) and International Standard Organization(ISO22674, 2006), using four types of alloys(one type of Ni-Cr and one type of Co-Cr used for fixed prosthesis, and one type of Ni-Cr and one type of Co-Cr used for removable prosthesis). A total of 12 metal-release tests were performed at one-day, three-day, and two-week intervals, for up to 20 weeks. The metal ions were quantified using an Inductively Coupled Plasma-Atomic Emission Spectrometer. Results: The results showed that the extent of corrosion was higher in the ascending order of Jdium-$100^{(R)}$, Bellabond-$Plus^{(R)}$, Starloy-$C^{(R)}$, and Biosil-$F^{(R)}$. The lower the pH and the longer the elapsed time were, the greater the increase in metal corrosion. At pH 2.4, the release of Ni from Jdium-$100^{(R)}$, a Ni-Cr alloy, was up to 15 times greater than the release of Co from the Co-Cr alloy from two weeks over time, indicating that the Ni-Cr alloy is more susceptible to corrosion than the Co-Cr alloy. Conclusion: It is recommended that Co-Cr alloy, which is highly resistant to corrosion, be used for making dental prosthesis with a non-precious alloy for dental casting, and that non-precious alloy prosthesis be designed in such a way as to minimize the area of its oral exposure. For patients with non-precious alloy prostheses, a test of the presence or absence of periodontal tissue inflammation or allergic reaction around the prosthesis should be performed via regular examination, and education on the good management of the prosthesis is needed.

• The Journal of Korean Academy of Prosthodontics
• /
• v.55 no.1
• /
• pp.71-78
• /
• 2017

The retaining methods of implant prosthesis were classified into a screw-retained and a cement-retained type. A screw-retained prosthesis has many advantages, such as retrievability, preventing residual cement, while their disadvantages include the possibility of screw loosening and fracture, on the contrary advantages of cement-retained prosthesis are relatively low cost, but they are difficult to retrieve. To combine the advantages of both type, screw-cement retained prosthesis (SCRP) type have been introduced. But they still require ideal implant placement. So we introduce fiber post retained prosthesis without residual cement for preventing soft tissue trouble due to excessive cement.

• The Journal of Korean Academy of Prosthodontics
• /
• v.44 no.2
• /
• pp.207-216
• /
• 2006

Statement of Problem: To conduct a successful function of implant prosthesis in oral cavity for a long time, it is important that not only structure materials must have the biocompatibility, but also the prosthesis must be designed for the stress, which is occurred in occlusion, to scatter adequately within the limitation of alveolar bone around implant and bio-capacity of load support. Now implant which is used in clinical part has a very various shapes, recently the fixture that has tapered form of internal connection is often selected. However the stress analysis of fixtures still requires more studies. Purpose: The purpose of this study is to stress analysis of the implant prosthesis according to the different implant systems using finite element method. Material and methods: This study we make the finite element models that three type implant fixture ; $Br{\aa}nemark$, Camlog, Frialit-2 were placed in the area of mandibular first premolar and prosthesis fabricated, which we compared with stress distribution using the finite element analysis under two loading condition. Conclusion: The conclusions were as follows: 1. In all implant system, oblique loading of maximum Von mises stress of implant, alveolar bone and crown is higher than vertical loading of those. 2. Regardless of loading conditions and the type of system. cortical bone which contacts with implant fixture top area has high stress, and cancellous bone has a little stress. 3. Under the vertical loading, maximum Von mises stress of $Br{\aa}nemark$ system with external connection type and tapered form is lower than Camlog and Frialit-2 system with internal connection type and tapered form, but under oblique loading Camlog and Frialit-2 system is lower than $Br{\aa}nemark$ system.