• The Journal of Advanced Prosthodontics
• /
• v.5 no.4
• /
• pp.428-433
• /
• 2013

PURPOSE. The present study was aimed to evaluate the influence of implant contact ratio and stiffness of implant-surrounding materials on the resonance frequency analysis (RFA) values. MATERIALS AND METHODS. Seventy resin blocks that had the different amounts (100, 50, 30, 15%) of resin-implant contact (RIC) were fabricated. Ten silicone putty blocks with 100% silicone-implant contact were also made. The implants with ${\phi}5.0mm{\times}13.0mm$ were placed on eighty specimen blocks. The RFA value was measured on the transducer that was connected to each implant by Osstell Mentor. Kruskal-Wallis and Scheffe's tests (${\alpha}$=.05) were done for statistical analysis. RESULTS. The control resin group with 100% RIC had the highest RFA value of 83.9, which was significantly different only from the resin group with 15% RIC among the resin groups. The silicone putty group with 100% contact had the lowest RFA value of 36.6 and showed statistically significant differences from the resin groups. CONCLUSION. Within the limitations of this in vitro study, there was no significant difference in the RFA values among the resin groups with different RIC's except when the RIC difference was more than 85%. A significant increase in the RFA value was observed related to the increase in stiffness of material around implant.

• The Journal of Korean Academy of Prosthodontics
• /
• v.43 no.6
• /
• pp.745-750
• /
• 2005

Statement of problem. Resonance frequency analysis has been increasingly served as a non-invasive and objective method for clinical monitoring of implant stability. Many clinical studies must be required for standardized data using RFA. Purpose. This study was performed to evaluate RFA value changes in two anodized implant groups. Material and method. Among a total of 24 implants, twelve screw shaped implants as a test group (H2-R8.5) were manufactured, which had a pitch-height of 0.4 mm, an outer diameter of 4.3 mm, a length of 8.5 mm, and external hexa-headed, were turned from 5 mm rods of commercially pure titanium (ASTM Grade IV, Warantec Co., Seoul, Korea), and another twelve implants as a control group were $Br{\aa}nemark$ Ti-Unite MK4 (diameter 4.0 mm, length 8.5 mm). Each group was installed in tibia of rabbit. Two implants were placed in each tibia (four implants per rabbit). Test two implants were inserted in right side and control two in left side. ISQ values were measured using $Osstell^{TM}$ (Integration Diagnostics Ltd. Sweden) during fixture installation, and 12 weeks later and evaluated the RFA changes. Results. Mean and SD of baseline ISQ values of test group were $75.0{\pm}3.4$ and $68.7{\pm}8.1$ for control group. Mean and SO of ISQ values 12 weeks after implant insertion were $73.2{\pm}4.7$ for test group and $72.6{\pm}3.9$ for control group. There were no statistically significant differences between groups in ISQ values after 3 months (P>0.05). From the data, RFA gains after 3 months were calculated, and there was statistically significant difference between groups (P<0.05). Conclusion. Although there were RFA changes between groups, implant stability after experimental period shows alike tendency and good bone responses.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.34 no.2
• /
• pp.80-88
• /
• 2018

Purpose: Implant surface modification and implant design are the principle targets for achieving successful primary stability. The aim of this study was to measure implant stability quotient (ISQ) values of sandblasted, large-grit, acid-etched (SLA) implants with tapered straight body design during the healing period, and to determine the various factors affecting implant stability. Materials and Methods: To measure implant stability, resonance frequency analysis (RFA) was performed in 26 patients (13 women and 13 men) with 44 SLA implants with tapered straight body design. Implant stability (ISQ values) was evaluated at baseline and healing abutment connection (12 weeks), and the correlations between RFA and insertion torque (IT), bone quality, and jawbone were determined. Results: The mean ISQ value of the implants was $69.4{\pm}10.2$ at the time of implant placement (baseline) and $81.4{\pm}6.9$ at the time of healing abutment connection (P < 0.05). Significant differences were found between RFA and bone quality and between RFA and jawbone (P < 0.05). No significant differences were found between RFA and IT, insertion area, fixture diameter, and implant length (P > 0.05). Conclusion: ISQ values of SLA implants with tapered straight body design were high at baseline and healing abutment connection. It was concluded that SLA implants with tapered straight body design show improved primary and secondary stability, and that immediate or early loading may be applicable.

• The Journal of Korean Academy of Prosthodontics
• /
• v.43 no.1
• /
• pp.78-94
• /
• 2005

Purpose. The purpose of this study was to compare the effects of various surface treatments by measuring resonance frequency and histomorphometric analyses. Material and methods. In 5 adult dogs, the mandibular premolar were extracted. Six months later, 30 screw titanium implants (Dentium Co., Seoul, Korea) 6mm in length and 3.4mm in diameter, were placed in the mandibles of 5 dogs. Implants were divided into five groups following to surface treatment methods ; Group 1 is machined controls, Group 2 is sandblasted with large grit and acid-etched (SLA), Group 3 is anodized (Autoelectric Co., Korea, 660Hz, Duty10), Group 4 is hydroxyapatite(HA) coated by ion beam assisted deposition(E-beam), Group 5 is hydroxyapatite(HA) coated with Sol-gel coating process. Resonance frequency was measured implant placement immediately, and 3, 6 weeks and 10 weeks of healing perods. With the animal subject's sacrifice 10 weeks after implantation, implants were removed on bloc and histologic and computer-based histomorphometric analyses were performed. Histomorphometric analysis involved quantification of the entire bone to metal contact around the implants. Statistical analyses were performed using the SPSS for Windows (ver. 9.0 SPSS Inc.) Statistical differences were considered significant at P<0.05. Results. The results were as follows : 1) In five groups, mean value of resonance frequency analysis(RFA) were highest in group 5 (Sol-gel implant) at implantation and those of group 4 (E-beam)was highest at 10 weeks . but there was no correlation between surface treatments and RFA. 2) In all surface treatment groups, the RFA values of implants decreased until 3 weeks and increased to 10 weeks. 3) The percentage of direct bone-to-implant contact (BIC) had statistical significance between five groups in cancellous bone, (P<0.05) the percentage of bone density inside the thread had no statistical significance between five groups. (P>0.05) 4) There was a significant difference between cortical bone and cancellous bone in BIC. (P<0.05) and bone density. (P<0.05) 5) There was a correlation between the RFA value of implants at 10 weeks and BIC in cancellous bone, and between the RFA value of implants at 10 weeks and bone density in cortical bone. (P<0.05). Conclusions. These results indicate that surface treatment does not affect the implant stability in case of good bone quality.

• 대한치과보철학회:학술대회논문집
• /
• 2006.04a
• /
• pp.102-102
• /
• 2006

• Journal of Dental Rehabilitation and Applied Science
• /
• v.19 no.4
• /
• pp.291-296
• /
• 2003

The use of resonance frequency analysis (RFA) provides a possibility to clinically measure implant stability and osseointegration. The implant stability quotient (ISQ) value of RFA is well known that influenced by effective abutment length and stiffness of the implant in the surrounding tissues. Among these factors stiffness is not accurately defined histologically yet. And the purpose of this study was to find the histolgical relationship of RFA. 17 implants in 3 beagle dogs were used for this study. Among these implants 10 were survived for 7 months, 4 were survived for 3 months and 3 were immediate status after placement. Resonance frequency analyses were conducted and the dogs were sacrificed. Percentage of the bone to implant contact (BIC) in the interface, percentage of the mineralized bone (bone area) within the threads of the implant, and marginal bone level were measured under light microscopy. The correlation between resonance frequency and histomorphometric measurements were analysed and following results were obtained. 1. There was statistically significant correlation between ISQ value and BIC on healed implants. But ISQ value and BIC of all implants were not significantly correlated. (P<0.01) 2. Significant correlation between ISQ value and bone area was not found in this study. 3. There was statistically significant correlation between ISQ value and marginal bone level on all implants as well as on healed implants. (P<0.01).

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.29 no.5
• /
• pp.383-393
• /
• 2007

The aim of the present study is to investigate the effect of anodized surface of osseointegration implants by using of resonance frequency analysis (RFA) and histomorphometric analysis. A total of 96 screw-shaped implants were devided into 4 groups. Seventy-two implants were prepared by electrochemical oxidation with 3 different ways; Group 1 (n=24) were prepared at galvanostatic mode in 0.25M sulfuric acid and phosphoric acid, Group 2 (n=24) were prepared at galvanostatic mode in calcium glycerophosphate and calcium acetate, and Group 3 (n=24) were prepared at galvanostatic mode in 0.25M sulfuric acid and phosphoric acid followed by Calcium metaphosphate(CMP) coating. Control group (n=24) were the RBM surfaced implants. The implants were placed in the mandibles of 12 mini pigs. Bone tissue responses were evaluated by resonance frequency analysis(RFA) and histomorphometric analysis that were undertaken at 2, 4 and 6weeks after implant placement. The following result were obtained. 1. Twenty-two of 96 implants (4 in control group, 5 in group 1, 7 in group 2, and 6 in group 3) were failed due to faliure of osseoitegration. The failure rate of osseointegration was 22.9%. 2. The mean values of RFA in control, group 2 and groups 3 showed the similar values, but there was no significant difference among groups. 3. Histomorphometric evaluation demonstrated significantly higher bone-to-implant contact ratio in group 2 at 3 and 4 weeks after implant placement than other groups (p<0.05), but there was no significant difference among groups at 6weeks after implant placement.

• The Journal of Korean Academy of Prosthodontics
• /
• v.42 no.3
• /
• pp.294-300
• /
• 2004

The present experimental study was designed to address two issues. The first was to investigate whether oxidation voltage of titanium implants influenced bone tissue responses after an in vivo implantation. The second aim was to investigate secondary stability change after 1 to 3months period. Screw-shaped implants with a wide range of oxide properties were prepared by electrochemical oxidation methods, where the oxide thickness varied in the range of $3-15{\mu}m$. The micro structure revealed pore sizes of $1-3{\mu}m$, the crystal structures of the titanium oxide were amorphous, anatase and a mixture of anatase and rutile type. Bone tissue responses were evaluated by resonance frequency measurements that were undertaken 1 to 3months after insertion in the rabbit tibia. It was concluded that no statistical difference of RFA values was found between the groups, RFA gains after Imonth and 3months were calculated.

• The Journal of Korean Academy of Prosthodontics
• /
• v.43 no.2
• /
• pp.248-257
• /
• 2005

Statement of problem. Cortical bone plays an important role in the primary implant stability, which is essential to immediate/early loading. However, immediate load-bearing capacity and primary implant stability according to the change of the cortical bone thickness have not been reported. Purpose. The objectives of this study were (1) to measure the immediate load-bearing capacity of implant and primary implant stability according to the change of cortical bone thickness, and (2) to evaluate the correlation between them. Material and methods.48, screw-shaped implants (3.75 mm$\times$7 mm) were placed into bovine rib bone blocks with different upper cortical bone thickness (0-2.5 mm) and resonance frequency (RF) values were measured subsequently. After fastening of healing abutment. implants were subjected to a compressive load until tolerated micromotion threshold known for the osseointegration and load values at threshold were recorded. Thereafter, RF measurement after loading, CT taking and image analysis were performed serially to evaluate the cortical bone quality and quantity. Immediate load-bearing capacity and RF values were analyzed statistically with ANOVA and post-hoc method at 95% confidence level (P<0.05). Regression analysis and correlation test were also performed. Results. Existence and increase of cortical bone thickness increased the immediate load-bearing capacity and RF value (P<0.05) With the result of regression analysis, all parameter's of cortical bone thickness to immediate load-bearing capacity and resonance frequency showed significant positive values (P<0.0001). A significant high correlation was observed between the cortical bone thickness and immediate load-beating capacity (r=0.706, P<0.0001), between the cortical bone thickness and resonance frequency (r=0.753, P<0.0001) and between the immediate load-bearing capacity and resonance frequency (r=0.755, P<0.0001). Conclusion. In summary, cortical bone thickness change affected the immediate load-baring capacity and the RF value. Although RF analysis (RFA) is based on the measurement of implant/bone interfacial stiffness, when the implant is inserted stably, RFA is also considered to reflect implant/bone interfacial strength of immediately after placement from high correlation with the immediate load-baring capacity. RFA and measuring the cortical bone thickness with X-ray before and during surgery could be an effective diagnosis tool for the success of immediate loading of implant.

• Maxillofacial Plastic and Reconstructive Surgery
• /
• v.32 no.2
• /
• pp.107-111
• /
• 2010

Purpose: The aim of this study is to compare the stability between Mg-incorporated implant, TiUnite and Machined implant. Materials and Methods: Premolars of 3 Mini pigs (24 months) were extracted. After 2 months later, total 27 fixtures of implants (9 of each design : Machined/ TiUnite/ Mg-incorporated) were inserted into the mandible of 3 mini-pig. Implant stability was estimated by RFA in installation to 2, 4 & 6 weeks. Statistical analysis of RFA values was performed with time and between groups using repeated measure ANOVA and turkey's multiple comparison test. Results: In analyzing the mean value for the observation periods, three types of implants yielded a slight decrease in RFA mean value after 2 week, followed by increase at 4-6 weeks. Mg incorporated oxidized implants demonstrated significantly higher RFA mean values at 6 weeks comparing other groups. The difference of RFA value with time and between groups was statistically significant. Conclusion: We concluded that Mg implants may reduce failure rates of clinical implants In the early period of bone healing and Mg implants may shorten the bone healing time from surgery to functional loading.