Statement of problem. Primary implant stability has long been identified as a prerequisite to achieve osseointegration. So the application of a simple, clinically applicable noninvasive test to assess implant stability and osseiointegratation are considered highly desirable. Purpose. The purpose of this study was to evaluate the ISQ value and the insertion torque of the 3 different implant system, then to evaluate whether there was a correlation between ISQ value and insertion torque; and to determine whether implant design has an influence on either insertion torque or ISQ value. Material and method. The experiment was composed of 3 groups: depending on the implant fixture design. Group1 was Bra.nemark type parallel implant in 3.75*7mm. Group2 was Oneplant type straight implant in 4.3*8.5mm. Group3 was Oneplant type tapered implant in 4.3*8.5mm. Depending on the density of the bone, 2 types of bone were used in this experiment. Type I bone represented for cortical bone, type II bone represented for cancellous bone. With the insertion of the implant in type I and type II bone, the insertion torque was measured, then the ISQ value was evaluated, and then the correlation between insertion torque and ISQ value was analyzed Result and conclusion. Within the limitations of this study, the following conclusions were drawn. 1. Within the 3 different implants, the insertion torque value and ISQ value were higher in type I bone, when compared with type II bone.(p<0.05) 2. In type I and type II bone, Oneplant type tapered implant has the highest value in insertion torque.(p<0.05) 3. In type I and type II bone, there was no difference in ISQ values among the 3 types of implant. (p>0.05) 4. Significant linear correlation was found in Bra.nemark type parallel implant: 3.75*7mm in type II bone.
Osseointegration ; Torque*

Statement of problem. Osseointegration is important mechanism of dental implant but it is not easy to evaluate. Indirect measurement is non-invasive and clinically applicable but they need more study about correlation between indirect values and degree of osseointegration. Purpose. The aims of this study were to evaluate the coefficient of correlation between indirect measurement and direct measurement under different healing time, and assessment of effect of initial insertion torque to the implant stability. Material and Methods. 20 rabbits received 3 implants on each side of tibia. Three kinds of implants (machined surface implant, Sandblasted with Large grit and Acid etched implant, Resorbable Blast Media treated implant) were used. During the surgery implant insertion torque were measured with OsseocareTM. After the 1, 4, 8, 12 weeks of healing time, animals were sacrificed and stability values (Implant Stability Quotient with OsstellTM, removal torque with torque gauge) were measured. Results. The Bone quality of rabbit tibia was classified into 2 groups according to the insertion torque. Resonance frequency analysis (ISQ) and removal torque showed positive correlation until 4th week (r=0.555, p=0.040). After 8th week (r=-0.011, p=0.970) the correlation became weak and it turned negative at 12th week (r=-0.074, p=0.801). Insertion torque and ISQ showed changing correlation upon the healing time (1st week: r=0.301, p=0.033, 4th week: r=-0.429, p=0.018, 8th week: r=0.032, p=0.865, 12th week: r=-0.398, p=0.029). Insertion torque and removal torque has positive correlation but it was not statistically significant (1st week: r=0.410, p=0.129, 4th week: r=-0.156, p=0.578, 8th week: r=0.236, p=0.398, 12th week: r=-0.260, p=0.350). Conclusion. In this study, bone quality may affect the degree of osseointegration positively during healing time and correlation between ISQ and degree of osseointegration can be different according to the healing time and bone quality.
Animals ; Dental Implants ; Osseointegration ; Rabbits ; Tibia ; Torque*

Statement of problem. Higher fracture rates were reported for Branemark implants placed in the maxilla and for 3.75 mm diameter implants installed in the posterior region. Purpose. The purpose of this study was to investigate the fracture of a fixture by finite element analysis and to compare different diameter of fixtures according to the level of alveolar bone resorption. Material and Methods. The single implant and prosthesis was modeled in accordance with the geometric designs for the 3i implant systems. Models were processed by the software programs HyperMesh and ANSA. Three-dimensional finite element models were developed for; (1) a regular titanium implant 3.75 mm in diameter and 13 mm in length (2) a regular titanium implant 4.0 mm in diameter and 13 mm in length (3) a wide titanium implant 5.0 mm in diameter and 13 mm in length each with a cementation type abutment and titanium alloy screw. The abutment screws were subjected to a tightening torque of 30 Ncm. The amount of preload was hypothesized as 650 N, and round and flat type prostheses were 12 mm in diameter, 9 mm in height were loaded to 600 N. Four loading offset points (0, 2, 4, and 6 mm from the center of the implants) were evaluated. To evaluate fixture fracture by alveolar bone resorption, we investigated the stress distribution of the fixtures according to different alveolar bone loss levels (0, 1.5, 3.5, and 5.0 mm of alveolar bone loss). Using these 12 models (four degrees of bone loss and three implant diameters), the effects of loading offset, the effect of alveolar bone resorption and the size of fixtures were evaluated. The PAM-CRASH 2G simulation software was used for analysis of stress. The PAM-VIEW and HyperView programs were used for post processing. Results. The results from our experiment are as follows: 1. Preload maintains implant-abutment joint stability within a limited offset point against occlusal force. 2. Von Mises stress of the implant, abutment screw, abutment, and bone was decreased with increasing of the implant diameter. 3. With severe advancing of alveolar bone resorption, fracture of the 3.75 and the 4.0 mm diameter implant was possible. 4. With increasing of bending stress by loading offset, fracture of the abutment screw was possible.
Alloys ; Alveolar Bone Loss ; Bite Force ; Bone Resorption ; Cementation ; Finite Element Analysis* ; Joints ; Maxilla ; Prostheses and Implants ; Titanium ; Torque

Statement of problem. Proliferation of Candida albicans is primarily within the plaque on the fitting surface of the denture rather than on the inflamed mucosa. Consequently, the treatment of the denture is equally important as treatment of the tissue. Cleansing and disinfection should be efficiently carried-out as the organisms can penetrate into the voids of the acrylic resin and grow in them, from which they can continue to infect and reinfect bearing tissues. Purpose. The purpose of this study was to evaluate the applicability of photocatalytic reaction to eliminate Candida albicans from acrylic resin denture base, and to investigate the antifungal effect with various UVA illumination time. Materials and Methods. The specimens were cured by the conventional method following the manufacturer's instruction using thermal polymerized denture base resin (Vertex RS; Dentimex, Netherlands). TiO2 photocatalyst sol(LT), which is able to be coated at normal temperature, was made from the Ti-alkoxide progenitor. The XRD patterns, TEM images and nitrogen absorption ability of the TiO2 photocatalyst sol(LT) were compared with the commercial TiO2 photocatalyst P-25. The experimental specimens were coated with the mixture of the TiO2 photocatalyst sol(LT) and binder material (silane) using dip-coater, and uncoated resin plates were used as the control group. Crystallinity of TiO2 of the specimen was tested by the XRD. Size, shape and chemical compositions were also analyzed using the FE-SEM/EDS. The angle and methylene blue degradation efficiency were measured for evaluating the photocatalytic activity of the TiO2 film. Finally, the antifungal activity of the specimen was tested. Candida albicans KCTC 7629(1 ml, initial concentration 105cells/ml) were applied to the experiment and control group specimens and subsequently two UVA light source with 10W, 353 nm peak emission were illuminated to the specimens from 15cm above. The extracted 2 microliter of sample was plated on nutrient agar plate (BactoTM Brain Heart Infusion; BD, USA) with 10 minute intervals for 120 minute, respectively. It was incubated for 24 hours at 37 degree C and the colony forming units (CFUs) were then counted. Results. Compared the characteristics of LT photocatalyst with commercial P-25 photocatalyst, LT were shown higher activity than P-25. The LT coated experimental specimen surface had anatase crystal form, less than 20 nm of particle size and wide specific surface area. To evaluate the photocatalytic activity of specimens, methylene blue degradation reaction were used and about 5% of degradation rate were measured after 2 hours. The average contact angle was less than 20.indicating that the LT photocatalyst had hydrophilicity. In the antifungal activity test for Candida albicans, 0% survival rate were measured within 30 minute after irradiation of UVA light. Conclusion. From the results reported above, it is concluded that the UVA-LT photocatalytic reaction have an antifungal effect on the denture surface Candida albicans, and so that could be applicable to the clinical use as a cleaning method.
Absorption ; Agar ; Brain ; Candida albicans* ; Candida* ; Crystallins ; Denture Bases* ; Dentures* ; Disinfection ; Heart ; Hydrophobic and Hydrophilic Interactions ; Lighting ; Methylene Blue ; Mucous Membrane ; Nitrogen ; Particle Size ; Polymers ; Stem Cells ; Survival Rate

Statement of problem. There have been many studies about marginal discrepancy of single restorations made by various systems and materials. However most of the statistical inferences are not definite because of sample size, measurement number, measuring instruments, etc, and there have been few studies about the marginal fit of the Digident CAD/CAM zirconia ceramic crowns. Purpose. The purpose of this study was to compare the marginal fit of the anterior single restorations made by using the Digident CAD/CAM zirconia ceramic crowns with metal-ceramic restorations and to obtain more accurate information by using a large enough sample size and by making sufficient measurements per specimen. Material and Methods. The crowns were made from one extracted maxillary central incisor prepared with a 1mm shoulder margin and 6.taper walls by milling machine. The in vitro marginal discrepancies of the digident CAD/CAM zirconia ceramic crowns and control groups(metal ceramic crowns) were evaluated and compared. Twenty crowns per each system were fabricated. Measurements of a crown were recorded at 50 points that were randomly selected for marginal gap evaluation. Parametric statistical analysis was performed for the results. Conclusion. Within the limitations of this in vitro study, the following conclusions were drawn: 1. Mean gap dimensions and standard deviations at the marginal opening for maxillary incisal crowns were 88+/-10microm for the control (metal-ceramic crowns), 92+/-4microm for Digident CAD/CAM zirconia ceramic crowns. 2. Marginal gap between Digident CAD/CAM zirconia ceramic crowns and metal ceramic crowns did not show significant difference (P>.05). 3. The Digident CAD/CAM zirconia ceramic crowns and metal ceramic crowns showed clinically acceptable marginal discrepancy.
Ceramics* ; Crowns* ; Incisor ; Sample Size ; Shoulder

No abstract available.
Academies and Institutes

The implant-supported fixed dental prosthesis in irradiated maxilla needs meticulous treatment planning due to low bone healing capacity. All-on-4 concept implantation can reduce the number of implants to be placed avoiding bone grafting procedure. Conventionally, prefabricated angled abutments for tilted implants have been used. However, in this case, it was replaced with computer-aided design and computer-aided manufacturing (CAD/CAM) abutment. This case report described all-on-4 concept implantation and fabrication of CAD/CAM zirconia fixed dental prostheses using CAD/CAM titanium abutments.
Bone Transplantation ; Ceramics* ; Computer-Aided Design ; Dental Prosthesis* ; Maxilla* ; Titanium

In case of the insufficient horizontal bone loss, a regular diameter implant is not possible without lateral bone augmentation. In this situation, narrow diameter implants (NDIs) could be the alternative to lateral bone augmentation procedures. However, complication generally expected with the NDI is implant fracture. Recently, the survival rate and success rate of NDI in the posterior region are similar to that of standard-diameter implants (SDIs). These 3 case reports demonstrate the incorporation of NDI to replace missing mandibular posterior teeth. So far, the follow-up examination period was maintained and no unusual complications were presented for more than four years. Long term follow-up clinical data are needed to confirm the excellent clinical performance of these implants.
Alloys* ; Dental Implants ; Follow-Up Studies ; Rehabilitation* ; Survival Rate ; Tooth

Loss of posterior support may cause extrusion of antagonistic teeth and excessive wear of remaining teeth which often leads to the destruction of the occlusal plane. In such cases, it is critical to verify the need to increase vertical dimension of occlusion (VDO). Should you increase VDO, provisionalization is crucial in evaluating function and esthetics. Double scanning technique is a useful method when fabricating definitive restoration that mimic provisional restoration. In this case, a patient with apparently no loss of VDO and insufficient interocclusal space for dental materials due to loss of posterior support and extrusion of antagonistic teeth was rehabilitated using double scanning technique.
Dental Materials ; Dental Occlusion ; Esthetics ; Humans ; Methods ; Rehabilitation* ; Tooth ; Vertical Dimension

Maxillofacial defect comes from congenital defect, trauma and surgical resection. Patients with intraoral defect are commonly related to maxillary defect and they need prosthetic rehabilitation. Functional reconstruction of partially edentulous mandible has many limitations. However, if both condyles are intact, maxillofacial prosthesis using partial denture give competent results. In this case, a patient of 58 year-old male has a defect on palate and left mandibular posterior teeth from gunshot. The maxillary defect of this patient is Class IV according to Aramany classification and the mandibular one is Type V according to Cantor and Curtis classification. For retention of the obturator, remaining teeth are fully utilized and artificial teeth are arranged harmoniously to provide stable occlusion. Mandibular RPD covered limited range of deformed soft tissue derived from mandibular resection surgery. With these treatments, the patient in this case showed improvements in mastication, swallowing and speech.
Classification ; Congenital Abnormalities ; Deglutition ; Denture, Partial ; Denture, Partial, Removable ; Humans ; Male ; Mandible ; Mastication ; Maxillofacial Prosthesis ; Palate ; Rehabilitation* ; Tooth ; Tooth, Artificial