No abstract available.
Osseointegration*

STATEMENT OF PROBLEM: Standard type of ITI solid implant model in the 6.2mm thick jaw bone was axisymmetrically modelled for finite element stress analyses. PURPOSE: Primary objective was to investigate the influences of the characteristic design configuration of the ITI solid implant model on the bone stress with the course of osseointegration process at the bone/implant interfaces. To simulate the characteristics of the osseointegration process, five different stages of the bone/implant interface model were implemented. As load conditions, vertical load of 50N was taken into consideration. Bone at the cervical region of implant was the areas of concern where the higher level of stress were likely to take place. RESULTS: The results indicated that rather slightly different stress level could be obtained as a function of the osseointegration conditions. CONCLUSION: Under vertical load, the lower level of stress was observed at the cervical cortical bone in the initial and final stages of osseointegration. Relatively higher stress level, however, was observed during the transitional stages where the osseointegration at the cancellous bone interface were yet to fully develop.
Jaw ; Osseointegration*

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*

In clinical therapy, the current goal of dental implants is to enhance quantity and quality of osseointegration. Surface roughness and oxide structure are considered to influence the behavior of adherent cells. The purpose of this study is to evaluate the effect of different surface treatment on cellular response. The attachment and proliferation of osteoblast-like cell on sandblasted, sandblasted and etched, thermal oxidated surfaces have been compared. Sandblasting was done with Al2O3 particles(grain size of 50micrometer), etching was processed with NH4OH : H2O2 : H2O(1:1:5) at 90degrees C for 1 minute. Thermal oxidation was followed sandblasting and etching at 400degrees C, 600degrees C, 800degrees C for 2 hours. Measurement of surface roughness after the different treatment did not show any differences of Ra value between terated surfaces. Cell attachment and proliferation were increased during experiment period, but no difference was observed. SEM evaluation revealed a similar pattern of osteoblastlike cells, well attached with dendritic extension and producing numerous matrix vesicles on cell surface. The results of this study showed that oxide layer alteration by thermal oxidation did not affect the attachment and proliferation of osteoblast-like cells. This suggests the possibility that the cellular responses are further influenced by surface roughness than titaniun oxide structure. This study was supported by a grant(HMP-98-G-2-035-B) of the HAN(highly advanced National) Projected, Ministry of Health & Welfare, R.O.K
Dental Implants ; Osseointegration ; Osteoblasts

The purpose of this study is to examine the effect of partial osseointegration situation on bone loading patterns around two different free-standing screw shaped implants (Nobel Biocare, Gothenburg, Sweden and Degussa-Huls, Hanau, German). Two dimensional axisymmetric Finite element models of two implants(10mm length and 4mm diameter) were created according to different bone quantity, quality and osseointegration ratio in maxilla and mandible bone. At the same time uni-cortical and bi-cortical fixation were analyzed. Generally, full bond case showed less stress than partial bond case in overall area and mandibular model showed less amount of stress than that of maxilla model. Maximum stress of the Branemark implant is higher than that of ANKYLOS regardless of bondingratio at crestal and apex region. However, more stress concentration was noted in ANKYLOS implant at screw body area especially in mandible. The effect of bicortical fixation on crestal bone stress reduction is dramatical in mandible however, there was no significant effect in maxillary case. The effect of partial bond on stress distribution was more significant at screw body and apex region than in crestal region. Partial bond cases demonstrated greater stress accumulation in trabecular bone than cortical bone. It is concluded that the more accurate model of implant and bone which affects stress and strain distribution is needed to mimic in vivo behavior of implants.
Mandible ; Maxilla ; Osseointegration* ; Sweden

STATEMENT OF PROBLEM: Initial stability of implant is an important factor for predicting osseointegration. It requires a rapid, non-invasive, user-friendly technique to frequently assess the implant stability and the degree of osseointegration. PURPOSE: The aim of this study was to evaluate the correlation between the resonance frequency analysis (RFA) and the radiographic method for peri-implant bone change under in vitro conditions. MATERIAL AND METHOD: Twenty implants of 3.75 mm in diameter(Neoplant, Neobiotech, Korea) were used. To simulate peri-implant bone change, 2 mm-deep 45degrees range horizontal defect and 2 mm-deep 90 degrees range horizontal defect area were serially prepared perpendicular to the X-ray beam after conventional implant insertion. Customized film holding device was fabricated to standardize the projection geometry for serial radiographs of implants and direct digital image was obtained. ISQ values and gray values inside threads were measured before and after periimplant bone defect preparation. Results. Within a limitation of this study, ISQ value of resonance frequency analysis was changed according to peri-implant bone change (p<0.05) and gray value of radiographic method was changed according to peri-implant bone change (p<0.05). There was no correlation between the ISQ value and the gray value for peri-implant bone change (p>0.05). But, in horizontal defect condition, relatively positive correlation were between ISQ and gray values(r=0.663). CONCLUSION: This results provided a possibility that peri-implant bone change may be evaluated by both RFA and radiographic method.
Dental Implants ; Osseointegration ; Radiography

STATEMENT OF PROBLEM: Accurate fit between the implant components is important because the misfit of the implant components results in frequent screw loosening, irreversible screw fracture, plaque accumulation, poor soft tissue reaction, and destruction of osseointegration. PURPOSE: This study is to evaluate the machining accuracy and consistency of the implant fixture/abutment/screw interfaces of the internal connection system by using a Stereoscopic Zoom microscope and FE-SEM(field emission scanning electron microscope) MATERIALS AND METHODS: The implant systems selected in this study were internal connection type implants from AVANA(Osstem(R)), Bioplant(Cowell-Medi(R)), Dio(DIO(R)), Neoplant(Neobiotech (R)), Implantium(Dentium(R))systems. Each group was acquired 2 fixtures at random. Two piece type abutment and one piece type abutment for use with each implant system were acquired. Screw were respectively used to hold a two piece type abutment to a implant fixture. The implant fixtures were perpendiculary mounted in acrylic resin block. Each two piece abutment was secured to the implant fixture by screw and one piece abutment also secured to the implant fixture. Abutment/fixture assembly were mounted in liquid unsaturated polyester. All samples were cross-sectioned with grinder-polisher unit. Finally all specimens were analysed the fit between implant fixture/abutment/screw interfaces Results and CONCLUSIONS: 1. Implant fixture/abutment/screw connection interfaces of internal connection systems made in Korea were in good condition. 2. The results of the above study showed that materials and mechanical properties and quality of milling differed depending on their manufacturing companies.
Korea ; Osseointegration ; Polyesters

The surface properties of implant are responsible to provide mechanical stability by creating an intimate bond between the bone and implant; hence, play a major role on osseointegration process. The current study was aimed to measure surface characteristics of titanium modified by a pulsed Nd:YAG laser. The results of this study revealed an optimum density of laser energy (140 Jcm⁻²), at which improvement of osteointegration process was seen. Significant differences were found between arithmetical mean height (Ra), root mean square deviation (Rq) and texture orientation, all were lower for 140 Jcm⁻² samples compared to untreated one. Also it was identified that the surface segments were more uniformly distributed with a more Gaussian distribution for treated samples at 140 Jcm⁻². The distribution of texture orientation at high laser density (250 and 300 Jcm⁻²) were approximately similar to untreated sample. The skewness index that indicates how peaks and valleys are distributed throughout the surface showed a positive value for laser treated samples, compared to untreated one. The surface characterization revealed that Kurtosis index, which tells us how high or flat the surface profile is, for treated sample at 140 Jcm⁻² was marginally close to 3 indicating flat peaks and valleys in the surface profile.
Osseointegration* ; Surface Properties ; Titanium*

Anchorage plays an important role in orthodontic treatment. Endosseous implants may be considered adequate firm anchorage. However, chinicians have hesitated to use endosseous implants as orthodontic anchorage because of limited implantation space, high cost, and long waiting period before osseointegration occurs. Recently, some clinicains have tried to use titanium miniscrews and microscrews in treatment due to their many advantages such as ease of insertion and removal, low cost, immediate loading, and the ability to place microscrews in any area of alveolar bone. The author treated a case with skeletal cortical anchorage using titanium microscrew implants. During six months of orthodontic force application from skeletal cortical anchorage, the author could get 4mm bodily retraction and intrusion of upper anterior teeth. The most outstanding result was a 1.5mm posterior retraction of the upper posterior teeth. The titanium microscrew implants and remained firm and stabel throughout treatment. These results indicate that skeletal cortical anchorage might be a very good option.
Osseointegration ; Titanium* ; Tooth

osseointegration of definitive implants, while the was provided with immediate esthetic and function. In addition, the provisional implant protects graft site. Also the provisional implant provides anchorage for orthodontic treatment and reconstructs vertical dimension in edentulous condyle fracture to practice functional therapy. The provisional implant system is a sound and economical method to achieve patient's immediate masticatory and esthetic function. Three cases are presented to document and illustrate the clinical application.]]>
Osseointegration ; Transplants ; Vertical Dimension