| BackgroundUnlike fixed dentures, removable dentures and fixed-removable joint denture, implant denture has become the preferred method for repairing missing tooth for it can maintaining alveolar bone health, with similar bite force like natural teeth, does not damage adjacent teeth, retention strong, beautiful and comfortable etc. Although 10 years follow-up showed titanium implants harvest can reached to 90-95%, but failure cases still to be reported. Studies have shown that peri-implantitis is an important cause of the failure of the implant loosening, for it will leads to soft tissue inflammation, bone absorbing and periodontal pockets. Based on this, the development of the superior antibacterial properties, is conducive to the types of antimicrobial with osteogenesis surface modification has become an important aspect of implant research.Titanium implants with its excellent biocompatibility, corrosion resistance, etc., has become the most commonly used implant materials. However, long-term study found that the titanium-based implants remain poor biological activity, combined with the surrounding bone tissue strength decreases healing time and other issues that affect the patient’s work and life, reducing their quality of life. To further improve the titanium and titanium implants and bone conduction biological activity, better osteogenic effect and excellent antibacterial properties, combined with a variety of treatment methods for treating the surface has become to a trend.In recent years, Sand Blast and Acid Etching(SLA), has become the international face on one of the most widely used implant surface, the surface biocompatibility and good mechanical properties of bone tissue guided the development of implant industry. SLA surface may formed two roughness. Primary roughness in favor of osteoblasts adhered and secondary roughness can stimulate osteoblast proliferation and differentiation, is conducive to the formation of osseointegration; Furthermore, in vivo experiments have demonstrated SLA can significantly increase the implant torque value. But the rough surface may enhance microbes, causing inflammation and lead to inflammation around the implant surface corrosion; SLA surface will leave some unfavorable particles, these deficiencies led scholars of Oral Implantology continue in-depth study.In recent years, with the "pro-metal" element known as tantalum (Ta) with its excellent biocompatibility, excellent corrosion resistance, stable biological characteristics gradually being introduced into the oral cavity fields. It has been reported that tantalum coating effectively prevent the release of titanium ions, improved biocompatibility, MTT colorimetric evaluation the cytotoxicity of L929 is 0 with tantalum coating. Kim loaded the porous tantalum onto the titanium implants, prepared modular dental implant, canine mandible can be observed the porous tantalum within significant bone tissue ingrowth. Implant infection is bacterial adhesion initiating factor, studies have shown that the adhesion to tantalum surface by Staphylococcus aureus and Staphylococcus epidermidis significantly lower than titanium, stainless steel, greatly reducing the failure rate of implant due to infection.Bone tissue is a highly ordered assembly of hierarchical organization of collagen fibers which are assembled from nanoscale units, then with mineral salt ions to micron-level unit like Haversian System, then assembled by the micron unit into cancellous bone, cortical bone and other tissue structures. Therefore, the surface of the implant construct by micro/nano-bionic surface helps to improve early bone implants binding. Micro-and nano-scale surface modification of titanium implants is the most promising way to long-term stability of bone. As an effective method for forming nano phenotype, sputtering is widely used to form nano-scale surface in the semiconductor and metal material surface to improve its performance and add new features. This technology has recently been introduced to the field of bio-engineering plant by making a rough surface, and shown to be effective in vitro biocompatibility.This study is divided into three parts:Chapter I The research of surface modification and surface character of Tantalum ion sputtering on Sand Blast and Acid Etching implant.Purpose:To observe and analysis the microstructure and elementary composition of Tantalum ion sputtering on Titanium implant, Tantalum ion sputtering on SLA implant and SLA implant.Method:1.The manufacture of the implants in this experiment. Processed pure Titanium implants according to Dentium SuperLine FX4008 implant data and divided into 3 groups. Group of Tantalum ion sputtering on implant:under the environment of 5×10-4 Pa,100℃ and 800 V Bias, high purity Tantalum(99.99%) particles sputtering in high concentration Argon gas flow(99.99%) and 60W direct current for 1 hour. Group of SLA implant:use 200μm Alumina particles bombardment implant of pure Titanium for 30s under 4.5×105 Pa, and then heated(60℃) in 18% hydrochloric acid and 49% sulfuric acid mixture for 30min. Group of Tantalum ion sputtering SLA implant:picked SLA implant which have been handled randomly, and dealt with them similar to the group of Tantalum ion sputtering on implant.2.Observe and analysis microstructure and elementary composition of implant: Observed the morphology of implant in different groups by FE-SEM. Analysised the elementary composition and content in different groups by EDS. Analysised the elements combining status on surface in different groups by XPS.Result:1.FE-SEM observe showed that surface of SLA implant was micro-grade porous mesh construe; the surface of Tantalum ion sputtering implant was nano mesh construe; the surface of Tantalum ion sputtering on SLA implant was micro/nano mesh construe.2.EDS analysis showed that there was no Ta ions existed on the surface of SLA implant.93.397% Ta ions existed on the surface of Tantalum ion sputtering implant; after Tantalum ion sputtering on SLA implant, around 33.208% Ta ions combined the SLA surface of implant.3. XPS atlas showed that there was no Ta element peak on the surface of SLA implant surface, it existed on the surface of Tantalum ion sputtering implant and Tantalum ion sputtering on SLA implant.Conclusion:Implant that has Ta element on the surface which is micro/nano composite can be made by Tantalum ion sputtering on SLA.Chapter Ⅱ Osseointegration studies of tantalum ion sputtering on SLA surface on tibia of Beagle dog.Purpose:To evaluate the osseointegration of Tantalum ion sputtering on SLA surface through the experiment on tibia of Beagle dog.Method:1.6 Beagle dogs were grouped into 3 groups randomly,2 dogs in each group.2.1mplant implantation:Reserved 6 implant holes since 5mm under knee epiphyseal line of both side of tibia of Beagle dog with 8mm separated. Implanted 24 implants in 3 different surfaces that prepared in the first experiment randomly.3.Measure and analysis of resonance frequency:Osstel resonance frequency analyzer was used to measure and record ISQ value of implant at 4th,8th and 12th week after all implants were completely in place.4.Execute experiment animals:executed the dogs after implanted the implants on tibia in the 4th,8th and 12th week by group with the method of air embolism in heart.5. Test of pull-out force of implant:separated the sample of tibia, pick 2 implants each of different surface processed in 3 ways in each group of experiment animals randomly and tested their pullout force.6. Observe and analysis of tissue section:beside sample which were besides the pullout force test, all other tibia samples were made to undecalcified hard tissue section, toluidine blue staining. Observed the formation of bone tissue around implant and measured the indicator of bone tissue formation in metrology.7. Statistical methond:SPSS 22.0 statistical analysis software were used to dealt it and the result were expressed in x±s. The variance of repeated measurement were used to analysis the various of integral. Compare indicators and timings in different groups:one-way analysis of variance were used when it satisfied homogeneity of variance, and LSD method were used to compare each 2; Welch detection were used which approximate to F detection in integral analysis when heterogeneity of variance, and Games-Howell detection were used to compare each 2; Variance analysis of repeated measure were used in comparison of different timing of each group. Assumption the test was a two-sided test, then consider that the difference of P<0.05 had statistics significance.Result:l.No Beagle dog accidental death during the experiment, the survival rate of implant was 100%.2.Accorded the general observation at the tibia sample, part of screw which covered the top of implant was embedded by bone tissue around and fibrous tissue, and bone tissue around the screw increased.3.Measurement of resonant frequency:ISQ value of implant in each group had no difference in statistics in 0th week; ISQ value of the Tantalum ion sputtering on SLA group was noteworthy higher than the Tantalum ion sputtering group at 4th, 8th,12th week; ISQ value of the Tantalum sputtering on SLA group had no difference in statistics with the SLA group at 8th and 12th week.4.Result of pullout force test:at the 4th,8th and 12th week, the pullout force of Tantalum sputtering group was noteworthy lower than SLA group and Tantalum ion sputtering on SLA group; pullout force of SLA group was noteworthy lower than Tantalum ion sputtering on SLA group.5.Neonatal woven bone can be seen at screw area of implant at 4th week. The weight of bone mass between bone tissue and neonatal bone increased, and the woven bone rebuild at the 8th week. The neonatal bone tend to maturation at the 12th week. The density of neonatal bone of compact bone area was higher than cancellous bone area, the density of neonatal bone around Tantalum ion sputtering on SLA implant was higher than SLA implant, the density of neonatal bone around Tantalum ion sputtering implant was the lowest.6.At 4th,8th and 12th week, BIC value of Tantalum ion sputtering group was noteworthy lower than SLA group and Tantalum ion sputtering on SLA group; BIC value of SLA group was noteworthy lower than Tantalum ion sputtering on SLA group.Conclusion:SLA implant which is processed by Tantalum ion sputtering can increase the success rate of osseointegration, and increase stability of implant.Chapter Ⅲ The influence of Tantalum ion sputtering on SLA implant to experimental peri-implantitis.Purpose:To evaluate the influence of Tantalum ion sputtering on SLA implant to peri-implantitis through compare the performance of Tantalum ion sputtering on SLA implant and SLA implant from the model of peri-implantitis of Beagle dog.Method:1.Tooth extraction:8 premolars were pulled out of both sides of under jaw of 6 Beagle dogs in minimally invasive way.2.Place the implants:8 weeks after wound healing, implanted STTSTSTS, TSSTSTST, STTTSSTS, TSSSTTST, STTSTSTS, SSTTSTST (S represent SLA implant, T represent Tantalum ion sputtering on SLA implant) from the left to the right side in turn in 6 Beagle dogs.3.Grouping:implant were tagged from no.1 to no.8 from the left to the right side after two-stage operation. No.1, no.2, no3, no6, no7, no8 implants were recorded as experimental group, twined 4-0 silk suture around the neck of implant abutment to made peri-implantitis model; no.3 and no.6 implant were recorded as the group of positive control with drug therapy; no.4 and no.5 implant were recorded as the group of base line which was not twined. Cleaned the dental plaque of no.4 and no.5 implant, and minocycline hydrochloride were used around gingiva of no.3 and no.6 implant twice a week, and the silk suture around the neck of implant abutment were checked whether it lose or not. Executed the experimental animals one week after the last examination. Tag twined T implant as group A, tag twined S implant as group B; tag twined and used minocycline hydrochloride T implant as group C; tag T implant as group D; tag S implant as group E.4.Measurement of clinical index:tested the clinical index of soft tissue around implant at the 2nd,4th,6th and 8th week after the abutment were placed, which included:gingival index; plaque index; modified Sulcus Bleeding Index and probing depth.5.Measurement of bone defect:flap the mucous and exposed the implant and bone defect area, measured the Defect Depth, DD and Defect Width, DW by periodontal probes under direct vision.6.Micro-CT scan:separated under jaw of Beagle dog after executed and micro-CT were used to scan, observe the bone tissue around implant.7.Observation of tissue section:made undecalcified hard tissue section of implant, toluidine blue staining. Light microscope were used to observe the bone structure and osteoclastic of the neck of implant.8.Statistic method:similar to chapter 2.Result:1.No accidental death happened to Beagle dog during the experiment. No rejection reaction after implant plancement.2. GI value of group B was noteworthy higher than group A and group C; GI value of group A was noteworthy higher than group C at the 4th week; group D and group E of base line had no different in statistics.3.PI value of group B was noteworthy higher than group C; PI value of group A was noteworthy higher than group C at the 4th and 6th week; PI value of group B was noteworthy higher than group A at the 4th,6th and 8th week; group D and group E had no different in statistics.4.mSBI value of group B was noteworthy higher than group A and group C; mSBI value of group A was noteworthy higher than group C at the 6th week; group D and group E had no different in statistics.5.PD value of group B was noteworthy higher than group A and group C; PD value of group A was noteworthy higher than group C at 4th,6th and 8th week; group D and group E had no different in statistics.6.DD and DW value of group B was noteworthy higher than group A and group C; DD and DW value of group A was noteworthy higher than group C; group D and group E had no different in statistics.7.Micro-CT scan:obvious osteoclastic can be observed in both group A and group B at the neck of implant, group B was more obvious than group A and lingual side was more obvious than buccal side, osteoclastic at the neck was less obvious than group A. Osteoclastic of peri-implant of Group D and group E of base line group contacted well.8.Check the peri-implant bone tissue in morphology:osteoclastic can be observed at the neck of implant of group A, group B and group C, and osteoclastic was more obvious at the neck of implant of group B. No obvious osteoclastic can be observed at the neck of implant at group D and group E.Conclusion:Tantalum ion sputtering on SLA implant, compare to SLA implant, can delay the development of peri-implantitis and lighten symptom of peri-implantitis. |
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