Summary: | 碩士 === 國立臺灣大學 === 臨床牙醫學研究所 === 98 === Objectives
Surface design and treatment on dental implant had been progressed rapidly, which caused reduction of healing time and raise of successful rate. Successful treatment with dental implant depends on a direct contact between dental implant and surrounding bone, which is known as osseointegration. Since the initial stability of implant was related to osseointegration, the geometric design on implant surface may play an important role in improving of initial stability of implant thus enhancing the osseointegration.
The purpose of this study is to evaluate the influence of modified thread design on osteointergration.
Materials and methods
Two different implant thread designs, the simplex type (ITI), and complex type (Biodenta) with same length (8mm) , diameter(3.3mm), surface treatment (SLA), were used in the present study. A total of 24 implants were inserted into the edentulous ridge in oral cavity of 3dogs and assigned into three healing periods, 4weeks, 8weeks and 12weeks. Each dog received implantation of 8 implant, which included 5 implants of complex type (Biodenta) and 3implants of simplex type(ITI). The assessments of implants are including clinical evaluation, resonance frequency analysis (RFA), and photographic record. And the dogs were sacrificed at the time interval of 4, 8,12 weeks after implantation for further histological analysis.
Results
It showed that implants of complex thread design had greater torque value during insertion. There was no statistically difference in initial stability, even though the ISQ value of implant with complex thread design was higher than simplex group. Furthermore there were two implants of complex group dislodged spontaneously leading to lower initial survival rate in complex group (86.67% in simplex group vs. 100% in complex group, p<0.05). However, there was no statistically difference in osseointegration and bone-implant-contact among two groups by means of histological analysis.
In the present study, the survival rate of either group was above 85%. Although superior initial stability in complex type implant group, the outcome of osseointegration was not as good as expecting. It seems that factors rather than design of implant such as the diameter of the drills, stress distribution around the implant preparation site might lead to fair osseointegration result. While a new complex implant system development, it seems be cautious on the design and stress distribution around the implant preparation site is warranted.
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