| Summary: | 碩士 === 國立成功大學 === 口腔醫學研究所 === 102 === Nowadays, using dental implants for replacement of missing teeth is a common and prior dental treatment choice. However, the establishment of osseointegration between implant and alveolar bone is the key point to provide primary stability for implants. There are many past literatures showed the implant design, including screw type, chemical component, topography of implant surface can affect the osseointegration. Furthermore, current trends in clinical dental implant therapy include use of dental implant surface embellished with nanoscale topographies. The nanoscale topography has the characteristics of stimulating cell adhesion, and enhancing cell proliferation. Several studies have shown nanoscale topography also enhances osteoblast differentiation. Moreover, the alveolar bone morphology and bone density of minipigs are closer to human, so the aim of the study is to applicate special nanoscale topography implant surface, and compare with the SLA (Sandblasted, Large grit, Acid-etched) surface implant that many literatures have showed high bone-to-implant contact and high remove torque, to evaluate the osseointegration in minipigs.
The study divids into three different surface implant. (1) control group—ITI system SLA implant. (2) test group—Type I and Type II nanoscale implant. First stage surgery(mimic the human edentulous ridge) — extract bilateral mandibular first to third premolar of milk teeth and underlying permanent premolar germs of 9 minipigs , and then wait 3 months for bone healing and during the period, take ISQ test (implant stability quotient) at implant insertion and sacrifice. Second stage ( implant insertion ) — insert 4 implants in every side of bilateral mandibular extraction area, totally 72 implants, and in addition, also insert 5 implants in every side of bilateral femur, which divide into (1) control group—non-surface treatment Type I implant. (2) test group—Type I and Type II nanoscale implant. Minipigs will be sacrificed at 8, 12, and 24 weeks after implant insertion. Then, histomorphometric analysis and bone-to–implant contact (BIC) of mandibular samples and removal torque value measurement of femur samples will be examined.
In removal torque value measurement (RTV), there was significant difference between type II and non-surface treatment type I implants, but no significant difference between type I and non-surface treatment type I implants in 8-week group. In 12-week group, the removal torque value of
type II implant was superior to type I and non-surface treatment type I implants. Moreover, there was no statistically difference in 24-week group.
In the histomorphometric analysis, there was no statistically difference in the bone-to–implant contact (BIC) between the three different implants in 8 and 24 weeks. However, in 12 weeks, there were significant differences between them, whose BIC values were (type I) 58±8 / (type II) 68±9/ (SLA) 82±4, respectively. The BIC values of type II and SLA implants increased about 5-6% from 8 weeks to 12 weeks, while type I implants remained in a stable state. In addition, both in 8 and 12 -week group, there were significant differences in ISQ values. SLA implants had superior ISQ values to type I and II implants. In 24-week group the ISQ value of type I implant showed a significant difference lower than type II and SLA implants.
The results of the study indicated that nanoscale with rough surface topography indeed can produce better bone anchorage than non-treatment surface. Moreover, the nanoscale topography implant can produce good osseointegration at early bone healing period and the performance of osseointegration in type II implant is closer to SLA implant. To sum up, the nanoscale topography implants may be a choice for clinical use, but it is still necessary for more in vivo studies to prove and evaluate other characteristics of nanoscale topography implants.
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