Differences in percussion-type measurements of implant stability according to height of healing abutments and measurement angle / 대한치과보철학회지

PURPOSE: The purpose of this study was to evaluate the effect of healing abutment height and measurement angle on implant stability when using Periotest and AnyCheck. MATERIALS AND METHODS: 60 implants were placed into artificial bone blocks. After implant insertion, 2, 3, 4 and 5 mm healing abutments were installed on 15 specimens, respectively. Insertion torque value, implant stability test, Periotest value were measured. Insertion torque value was controlled between 45 – 55 Ncm. AnyCheck was used for measuring implant stability test and Periotest M was used for measuring Periotest value. Implant stability test and Periotest value were measured at the angles of 0 and 30 degrees to the horizontal plane. Measured values were analyzed statistically. RESULTS: Insertion torque value had no significant difference among groups. When healing abutment height was higher, implant stability test and Periotest value showed lower stability. Also when measurement angle was decreased, implant stability test and Periotest value showed lower stability. CONCLUSION: When measuring stability of implants with percussion type devices, measured values should be evaluated considering height of healing abutments and measurement angle.

The effect of PostGraft(TM) on implants were installed at the tibia of ovariectomized rats / 대한치과보철학회지

PURPOSE: This study evaluated PostGraft(TM) which enhances implant stability and bone density. MATERIALS AND METHODS: Forty eight implants were installed at the tibia of ovariectomized rats. The group administrated with PostGraft(TM) was the experimental group, and the control group was not administrated. Implant stability was evaluated at the 2nd, 4th and 6th week by Periotest value, bone mineral density, bone-to-implant contact. These values were analyzed statistically with Mann-Whitney U test (P<.05). Histological analysis was evaluated at the 2nd, 4th and 6th week. RESULTS: According to the Periotest(R) measurement, both experimental and control groups showed decrease in values as time elapsed. Greater decrease was observed in the experimental group but there was no significant difference. By examining the radiographic images, both experimental and control groups showed tendency of increase in bone density. Greater increase was seen in the experimental group but there was no significant difference. According to the bone-to-implant contact measurement, both experimental and control groups showed increase in values as time elapsed. Greater increase was seen in the experimental group. At the 2nd and 4th week, there was no significant difference. But at the 6th week, there was significant difference (P<.05). By histological analysis, both experimental and control groups showed increase in bone formation as time elapsed. In addition, greater increase was seen in the experimental group. CONCLUSION: It could be concluded that the PostGraft(TM) medicated group showed better results in the bone density and osseointegration.

Comparion of stability in titanium implants with different surface topographies in dogs

STATEMENT OF PROBLEM: A few of studies which compared and continuously measured the stability of various surface treated implants in the same individual had been performed. PURPOSE: We aim to find the clinical significance of surface treatments by observing the differences in the stabilization stages of implant stability. MATERIAL AND METHODS: Eight different surface topographies of dental implants were especially designed for the present study. Machined surface implants were used as a control group. 4 nano-treated surface implants (20 nm TiO2 coating surface, heat-treated 80 nm TiO2 coating surface, CaP coating surface, heat treated CaP coating surface) and 3 micro-treated surface implants [resorbable blast media (RBM) surface, sandblast and acid-etched (SAE) surface, anodized RBM surface] were used as experiment groups. All 24 implants were placed in 3 adult dogs. Periotest(R) & ISQ values measured for 8 weeks and all animals were sacrificed at 8 weeks after surgery. Then the histological analyses were done. RESULTS: In PTV, all implants were stabilized except 1 failed implants. In ISQ values, The lowest stability was observed at different times for each individual. The ISQ values were showed increased tendency after 5 weeks in every groups. After 4 to 5 weeks, the values were stabilized. There was no statistical correlation between the ISQ values and PTV. In the histological findings, the bone formation was observed to be adequate in general and no differences among the 8 surface treated implants. CONCLUSIONS: In this study, the difference in the stability of the implants was determined not by the differences in the surface treatment but by the individual specificity.

AN EVALUATION OF PRECISION FIT OF IMPLANT-SUPPORTED PROSTHESIS USING THE PERIOTEST / 대한치과보철학회지

In this study, the Periotest value was measured with Periotest to evaluate precision fit of the 2-unit and 3-unit implant-supported prosthesis by modifying the size and location of ill-fitted conditions. The 2-unit prosthesis was fabricated with the right implant fitted incorrectly and the 3-unit prosthesis with the right and center implant fitted incorrectly. To evaluate the effects of the ill-fitted sizes, 4 groups were divided.:The control group being the accurately fabricated sample group fitted properly. Group 1 was constructed with 40micrometer ill-fitted conditions, group 2 with 70micrometer and group 3 with 100micrometer ill-fitted conditions. The Periotest value was measured at each implant site after tightening 10Ncm. The result was follows: 1. The PTV on the ill-fitted area in the 2-unit implant-supported prosthesis increased as the ill-fitted conditions increased. There was a statistically significant difference among groups(p<0.05). In the same ill-fitted sample, the PTV depending on the measured location demonstrated a statistically significant difference (p<0.05). 2. The PTV on the ill-fitted area of the 3-unit implant-supported with an ill-fitted condition in the right implant increased as the ill-fitted conditions increased. There was a significant difference among groups (p<0.05). In the same ill-fitted sample, the PTV depending on the measured location demonstrated a statistically significant difference (p<0.05). 3. In the 3-unit implant-supported prosthesis with ill fitting conditions in the center implant, the PTV on the ill-fitted area demonstrated a statistically significant difference between the control group, group 1 and group 2 (p<0.05). In the same ill-fitted sample, the PTV depending on the measured location demonstrated significant difference between the gap side and the adjacent side with over 70micrometer ill-fitted conditions (p<0.05). The results suggest that Periotest is a valuable objective method for evaluating the precision fit of an implant superstructure.