| dc.description.abstract | Several methods have been developed and applied to assess the interfacial situations after the dental implantation, but so far they are not able to provide the diagnostic standard for determining the success and the failure of the surgery. This study, establishing a newly noncontact resonance frequency (RF) detection technique, uses the procedure to perform bone defect and osseointegration evaluation in the implant-bone interface. Based on our method, the implant-bone structure was excited by the acoustic energy of a loudspeaker, and its vibration response was acquired with a capacitance displacement sensor. The spectral analysis was used to characterize the first peak RF value. Two types of in vitro defect models, single vertical dehiscence (SVD) and opposite vertical dehiscence (OVD), were 4 and 8 mm in depth and made for verification. The measurements of RF with each model being clamped in four heights (9, 10, 11, and 12 mm) were performed in their defect directions (0°, 45° and 90°), respectively. Afterward the finite element (FE) modal analysis was applied to determine mode shapes as well as their corresponding RFs of these bone defect models and compared simulated results with measuring RFs. Besides, two implants (1: coating, 2: non coating) were embedded in the left tibia of one rabbit. This noncontact method was used to perform the preliminary osseointegration detection and measured the RFs of the tibia in the lateral as well as the axial direction. Each in vitro and in vivo model was also checked by using an Osstell Mentor. The obtained two parameters, RF and ISQ (Implant Stability Quotient), were tested statistically by the ANOVA and the linear regression analysis for comparisons. In the in vitro test, the RFs and the ISQs of all defect models in four clamp heights decrease significantly (p < 0.05) along with the increase of the defect quantity; and the two parameters of each imperfection increase significantly (p < 0.05) when the clamp height increases. The RFs of SVD models linearly correlate with their corresponding ISQs in four clamp heights and two measuring orientations (0° and 90°). The numerical RF variations also present the same trend along with the changing of the defect structure and the surrounding boundary condition. Additionally, in the in vivo test, the RFs of two implants in the lateral direction are higher than that in the axial direction (p < 0.05). The axial RFs of the implant 1 in the 24 week are higher than that in the 16 week, and the lateral RFs of the implant 2 are higher than those of the implant 1 (p < 0.05). Other unapparent differences in some RF and ISQ detection need detailed animal experiments to confirm. Therefore, our technique can estimate availably the interfacial imperfection/osseointegration and is feasible for the assessment of the postoperative healing around a dental implant. | en_US |