• The Journal of Korean Academy of Prosthodontics
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• v.45 no.1
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• pp.71-84
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• 2007

Statement of problem: Implant surface characteristics plays an important role in clinical success and many studies have been made for improvement of success by changing surface roughness. Purpose: Appropriate increase of surface roughness increases the activity of osteoblast and enhance contact and retention between bone and implant. Material and method- Machined, SLA and RBM surface implants, which are the most commonly used implants were implanted into the tibia of rabbits and after 1 week, 4 weeks, 8 weeks and 12 weeks there were histologic and histomorphometric analysis and study for bone gradient and change of Ca/P ratio using EDS(Energy Dispersive X-ray Spectroscope). Results: Comparison of bone-implant contact showed no significant difference among each implant. In comparison of bone area rates, SLA showed higher value with significant difference at 1 week and 4 weeks, and SLA and RBM at 8 weeks than Machined implant (p<0.05). In analysis of bone constituents with EDS, titanium was specifically detected in new bones and the rates were constant by surface treatment method or period. In case of Ca/P ratio, according to surface treatment method, each group showed significant difference. Lots of old bone fragments produced during implantation remained on the rough surface of RBM implant surface and each group showed histological finding with active synthesis of collagen fibers until 12 weeks. In transmission electronic microscopic examination of sample slice after elapse of twelve weeks, tens nm of borderline (lamina limitans like dense line)was seen to contact the bone, on the interface between bone and implant. Conclusion: SLA and RBM implant with rough surface shows better histomorphometrical result and the trend of prolonged bone formation and maturation in comparison with Machined implant. In addition, implant with rough surface seems to be helpful in early stage bone formation due to remaining of old bone fragments produced in implantation. From the results above, it is considered to be better to use implant with rough surface in implantation.

• Journal of Periodontal and Implant Science
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• v.35 no.4
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• pp.921-937
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• 2005

Mechanical and chemical methods are the two ways to treat the implant surfaces. By using mechanical method, it is difficult to eliminate bacteria and by-products from the rough implant surface and it can also cause the structural change to the implant surface. Therefore, chemical method is widely used in order to preserve and detoxicate the implant surface more effectively. The purpose of this study is to evaluate the effect of tetracylcline- HCl on the change of implant surface microstructure according to application time. Implants with pure titanium machined surface, SLA surface and $TiO_2blasted$ surface were used in this study. Implant surface was rubbed with sponge soaked in 50mg/ml tetracycline - HCl solution for $\frac{1}{2}$ min., 1min., $1\frac{1}{2}$ min., 2 min., and $2\frac{1}{2}min.$ respectively in the test group and with no treatment in the control group. The sponge was soaked in every 30 seconds. Then, the specimens were processed for scanning electron microscopic observation. Based upon the analysis of photographs by three dentists who are not related with this study, the results were obtained as follows; 1. In the pure titanium machined surfaces, the control specimen showed a more or less rough machined surface composed of alternating positive and negative lines corresponding to grooves and ridges. After treatment, machining line was more pronounced for the control specimens. but in general, test specimens were similar to control. 2. In the SLA surfaces, the control specimen showed that the macro roughness was achieved by large-grit sandblasting. Subsequently, the acid-etching process created the micro roughness, which thus was superimposed on the macro roughness. Irrespective of the application time of 50mg/ml tetracycline - HCl solution, in general, test specimens were similar to control. 3. In the $TiO_2blasted$ surfaces, the control specimen showed the rough surface With small pits. The irregularity of the $TiO_2blasted$ surfaces with 50mg/ml tetracycline - HCl solution was lessened and the flattened areas got wider after 1 minute.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.5
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• pp.396-405
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• 2001

Osseointegrated implants are used for the fixation of dental prosthesis with good long-term clinical results. In an attempt to improve the quantity and quality of the bone-implant interface, numerous implant modification have been used. Implants surface modifications have been used such as titanium-plasma sprayed, hydroxyapatite-coating, sandblasted, sandblasted and acid-etched, acid-etched. Rough surface implants have greater implant surface area and enhance the bone-implant interface and improve stabilization. The purpose of present study was to evaluate light microscopic and scanning microscopic examinations and removal torque value of newly developed calcium phosphate blast and acid-etched implant in the femur of rabbits. Titanium plasma sprayed(TPS) implant served as controls. After 12 weeks of healing of the femurs of 12 rabitts, the implant-containing segments of femur were removed on bloc and bone block including sections. Histologic examination and histomorphometric and removal torque values comparision were made for two implants. Obtained results are follows: 1. Newly developed calcium phosphate blasted and acid-etched implants were in close contact with bone under light microscopic examinations. 2. New implants showed mean bone-to implant contact 59.8%, whereas TPS implants showed mean bone-to implant contact 54.5% (statistically no difference p<0.05). 3. New implants showed mean bone density 56.7%, whereas TPS implants showed mean bone density 49.2% (statistically difference p<0.05). 4. New implants demonstrated mean removal torque values 40.5Ncm, whereas the mean removal torque values of TPS implants ranged 39.3Ncm. No statistical differences(p<0.05) were observed between two groups of implants nor was there any difference between the two implants at the clinical level.

• The Journal of Korean Academy of Prosthodontics
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• v.48 no.1
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• pp.28-40
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• 2010

Purpose: The aim of this retrospective study was to provide long-term data about the correlation between multifactorial local factors and the survival of implants. Material and methods: During 19 years (1991 to 2009), 2796 implants were placed in 879 patients. From dental charts and radiographs, the following data were collected: patient's age at implant placement, gender, implant system, surface, length, diameter, location of implant placement, bone quality, primary stability, type of prosthesis. The correlations between these data and implant survival were analyzed. Statistical analysis was performed using Kaplan-Meier survival analysis, Chi-square test, odds ratio. Results: 1. Among the 2796 implants, 150 implants failed that resulted in a cumulative survival rate of 94.64%. The cumulative survival rate of smooth surface implants (91.76%) was lower than rough surface implants (96.02%). 2. Anatomic location, implant surface, diameter of smooth surface implant, primary stability, type of prosthesis, patient's age and gender were significantly associated with implant survival (P < .05). 3. No significant difference in implant survival was found in relation to the following factors: implant length, bone quality, diameter of rough surface implants and type of rough surface according to implant manufacturer (P < .05). Conclusions: Local factors such as anatomic location, implant surface, diameter of smooth surface implant, primary stability and type of prosthesis have a significant effect on implant survival.

• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.309-316
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• 2008

Purpose: The aim of this study was to determine the survival rates of implants placed in grafted maxillary sinuses and compare the results obtained with graft materials, implant surfaces and timing of implant placement. Materials and Methods: Between January 1996 and December 2005, 391 implants were placed in 161 patients who underwent sinus grafting treatment simultaneously or separately at Ewha Womans University Hospital. According to inclusion criteria, 272 implants were placed in 102 patients with 112 sinus grafts (30 females, 72 males), aged 26 to 88 years (mean age $49.0{\pm}9.7$). The follow-up period ranged from 12 to 134 months (mean F/U $47{\pm}32$). Survival rates were evaluated according to graft material, implant surface and timing of implant placement. The Kaplan-Meier procedure and the log rank (Mantel-Cox) test were used to estimate survival rates and test for equality of survival rates between different groups of patients. Results: Ten-year cumulative survival rate for implants placed in the grafted sinuses was 90.1%. The survival rates for autogenous bone, combination and bone substitutes were 94.6%, 85.9% and 100%, respectively (p > 0.05). According to implant surface, survival rates were 84.8% in machined group and 97.5% in rough group (p < 0.05). The survival rates were 92.9% in delayed group and 86.0% in simultaneous group (p > 0.05). Conclusion: Ten-year cumulative survival rate for implants placed in the grafted sinuses was 90.1%. Rough-surfaced implants have a higher survival rate than machined-surfaced implants when placed in grafted sinuses (p < 0.05).

• Journal of Periodontal and Implant Science
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• v.38 no.sup2
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• pp.385-394
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• 2008

Purpose: The aim of this study was to evaluate the factors affecting healing patterns of surgically created circumferential gap defects around implants in dogs. Materials and Methods: In four mongrel dogs, all mandibular premolars were extracted. After 8 weeks of healing periods, implants were submerged. According to the surface treatment, turned surface was designated as a group A and rough surface as a group B. In each dog, surgical defects on the left side were made with a customized tapered step drill and on the right with a customized paralleled drill. Groups were also divided according to the width of the coronal gaps: 1.0mm, 1.5mm, or 2.0mm. The dogs were sacrificed following 8 weeks and the specimens were analyzed histologically and histomorphometrically. Results: During the postoperative period, healing was uneventful and implants were well-maintained. As the size of the coronal gap was increased, the amount of bone-to-implant contact was decreased. The bone healing was greater in rough surface implants compared to the turned ones. About the defect morphology, tapered shape showed much bone healing and direct bone to implant contact even in the smooth surface implants. Conclusion: Healing of the circumferential defect around dental implant is influenced by the implant surface, defect width and the morphology of the defect. When using rough surface implants, circumferential gap defects within 2 mm do not need any kinds of regenerative procedures and the healing appeared to be faster in the tapered defect morphology than the paralleled one.

• Journal of Periodontal and Implant Science
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• v.24 no.1
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• pp.131-143
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• 1994

For maintenance of exposed implant in healthy state, it is necessary to treat the surface of implant fixture and provide the surface adjustable to surrounding tissues. Variable techniques have been introduced such as citric acid and air-abrasive system to treat the failed implant. Although when the rough surface of HA coated implant was exposed to oral environment, the surface treatment method with citric acid or air-abrasive system is effective for removal of bacterial endotoxin, it is unsuccessful to prevent plaque deposition due to difficulty in removal of rough surface of HA coated implant. Thus, in this study the method that removes bacterial endotoxin and makes smooch surface without alteration of surface characteristics was studied. HA coated disc manufactured by IMZ Co. Was treated with high speed diamond bur, low speed diamond bur, stone bur, rubber point, jetpolisher. And then its surface state was examined with profilometer and SEM to evaluate the surface smoothness, and its surface component was analyzed with EDX to evaluate wheter the surface characteristics were altered or not. As a result, following results were obtained. When the surface roughness of each implant disc was measured by profilometer, the group I showed a $R_{max}\;2.11{\mu}m$ and the group II, III, IV, V showed a $R_{max2}\;4.17{\mu}m$, $7.28{\mu}m$, $8.61{\mu}m$ and $39.44{\mu}m$ respectively. That is, surface smoothness was highest in the group I and it has been gradually decreased in the group II, III, IV and V. Under the SEM examination, the group I showed relatively smooth surface and the group II showed slightly rougher surface than the group I due to partially remaining HA particles while most HA particle was removed. The group III and IV showed rough topography due to HA particles that was not grinded, and HA coated surface in group V showed very irregular surface with deep groove and prominence. In cross-sectional view, the group I showed uniform surface, and the group III, IV showed rough surface due to remaining HA particles but the thickness of HA coating was remarkably reduced. The group II has similar pattern in group I, and the group V showed about $40{\mu}m$ thickness although it was not constant. By analysis of surface component with EDX, the group II in which the grinding was effective showed a small quantity of calcium and phosphorous and the group III, IV, in which the grinding was incomplete showed calcium and phosphorus peak. In all experimental group, no other than titanium, aluminum, calcium, phosphorus was observed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.6
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• pp.514-523
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• 2006

The purpose of the present study was to evaluate the effects of several implant surface treatments to the bone formation, by placing Machined implants, 75${\mu}m$ Calcium phosphate-blasted implants and $Al_2O_3$-blasted and acid-etched implants in rabbit tibia through histomorphometric study. Two animals of each group were sacrificed at 2, 4, 8 weeks. The specimens containing the implants were dehydrated and embedded into hard methylmethacrylate plastic. Thereafter, the sections were ground to 50${\mu}m$. The specimens were stained with Villanueva bone stain for a light microscopic study. The results were as follows; 1. When the surface roughness of three different implants was measured by Surfcorder, the Ra of the Machined group, the RBM group and the SLA group was 0.16${\mu}m$, 0.44${\mu}m$, and 1.08${\mu}m$. 2. When examining the surfaces of the implants in the scanning microscope, Machined implant has the smooth surface with a few scratches, RBM implant has the rough surface with curled ridges and valleys, and SLA implant has the rough surface structures such as sharp protruding parts and micropits measuring 1-2${\mu}m$ in diameter. 3. After 2 weeks of implantation, the percentage of bone-to-implant contact of the Machined group, the RBM group and the SLA group was 26.86%, 35.40% and 45.99%. However, its differences between each group decreased during the healing periods. 4. After 2 weeks of implantation, the percentage of bone area inside the threads of the Machined group, the RBM group and the SLA group were 21.55%, 30.43% and 41.18%. However, its difference of bone area between machined group and surface treatment groups was maintained but the difference within the surface treatment groups decreased during the healing periods. In summary, the amount of bone formation in RBM and SLA group was greater than Machined group in early healing stage. These results suggest that RBM and SLA implants can reduce the healing period for osseointegration and may be suitable for early function.

• Journal of Periodontal and Implant Science
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• v.31 no.4
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• pp.749-763
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• 2001

Osseointegrated titanium implants have become an integral therapy for the replacement of teeth lost. For dental implant materials, titanium, hydroxyapatite and alumina oxide have been used, which of them, titanium implants are in wide use today. Titanium is known for its high corrosion resistance and biocompatability, because of the high stability of oxide layer mainly consists of $TiO_2$. With the development of peri-implantitis, the implant surface is changed in surface topography and element composition. None of the treatments for cleaning and detoxification of implant surface is efficient to remove surface contamination from contaminated titanium implants to such extent that the original surface elemental composition. In this sights, the purpose of this study was to evaluate rough surface titanium implants by means of scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS) with respect to surface appearance and surface elemental composition. Moreover, it was also the aim to get the base for treatments of peri-implantitis. For the SEM and XPS study, rough surface titanium models were fabricated for control group. Six experimental groups were evaluated: 1) long-time room exposure, 2 ) air-powder abrasive cleaning for 1min, 3) burnishing in citric acid(pH1) for 1min, 4) burnishing in citric acid for 3min, 5) burnishing in tetracycline for 1min, 6) burnishing in tetracycline for 3min. All experimental treatments were followed by 1min of rinsing with distilled water. The results were as follows: 1. SEM observations of all experimental groups showed that any changes in surface topography were not detected when compared with control group. (750 X magnification) 2. XPS analysis showed that in all experimental groups, titanium and oxygen were increased and carbon was decreased, when compared with control group. 3. XPS analysis showed that the level of titanium, oxygen and carbon in the experimental group 3(citric acid treatment for 1min, followed by 1min of distilled water irrigation) reached to the level of control group. 4. XPS analysis showed that significant differences were not detected between the experimental group 1 and the other experimental groups except of experimental group 3. The Ti. level of experimental group 2, airpowder abrasive treatment for lmin followed by 1min of saline irrigation, was lower than the Ti. level of tetracycline treated groups, experimental group 5 and 6. From the result of this study, it may be concluded that the 1min of citric acid treatment followed by same time of rinsing with distilled water gave the best results from elemental points of view, and can be used safely to treat peri-implantitis.

• Journal of Periodontal and Implant Science
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• v.32 no.3
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• pp.615-630
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• 2002

Various long-term studies have shown that titanium implants as abutments for different types of prostheses have become a predictable adjunct in the treatment of partially or fully edentulous patients. The continuous exposure of dental implants to the oral cavity with all its possible contaminants creates a problem. A lack of attachment, together with or caused by bacterial insult, may lead to peri-implantitis and eventual implant failure. Removal of plaque and calculus deposits from dental titanium implants with procedures and instruments originally made for cleaning natural teeth or roots may cause major alterations of the delicate titanium oxide layer. Therefore, the ultimate goal of a cleaning procedure should be to remove the contaminants and restore the elemental composition of the surface oxide without changing the surface topography and harming the surrounding tissues. Among many chemical and mechanical procedure, air-powder abrasive have been known to be most effective for cleaning and detoxification of implant surface. Most of published studies show that the dental laser may be useful in the treatment of pen-implantitis. $CO_2$ laser and Soft Diode laser were reported to kill bacteria of implant surface. The purpose of this study was to obtain clinical guide by application these laser to implant surface by means of Non-contact Surface profilometer and X-ray photoelectron spectroscopy(XPS) with respect to surface roughness and atomic composition. Experimental rough pure titanium cylinder models were fabricated. All of them was air-powder abraded for 1 minute and they were named control group. And then, the $CO_2$ laser treatment under dry, hydrogen peroxide and wet condition or the Soft Diode laser treatment under Toluidine blue O solution condition was performed on the each of the control models. The results were as follows: 1. Mean Surface roughness(Ra) of all experimental group was decreased than that of control group. But it wasn't statistically significant. 2. XPS analysis showed that in the all experimental group, titanium level were decreased, when compared with control group. 3. XPS analysis showed that the level of oxygen in the experimental group 1, 3($CO_2$ laser treatment under dry and wet condition) and 4(Soft Diode laser was used under toluidine blue O solution) were decreased, when compared with control group. 4. XPS analysis showed that the atomic composition of experimental group 2($CO_2$ laser treatment under hydrogen peroxide) was to be closest to that of control group than the other experimental group. From the result of this study, this may be concluded. Following air-powder abrasive treatment, the $CO_2$ laser in safe d-pulse mode and the Soft Diode laser used with photosensitizer would not change rough titanium surface roughness. Especially, $CO_2$ laser treatment under hydrogen peroxide gave the best results from elemental points of view, and can be used safely to treat peri-implantitis.