Several kinds of substitute bone materials have been used for subantral augmentation.
In this case report, the subantral augmentation material composed of resolvent hydroxyapatite (OsteoGen™ Impladent, Int.) and demineralized human bone (Dembone™ Pacific Cost Tissue Bank), which were mixed 7:3 by weight percent, was implanted and the specimen was biopsied from patient's buccul side of sinus floor with implanted material.
In the histological findings 6 months after implantation, newly formed bone tissue was observed surrounding the implanted granule at the light microscopic level. Dembone was not identified in this specimen. On the other hand, OsteoGen™ was surrounded with newly formed bone tissue, but some granules were adjacent to the macrophage-like giant cells without an inflamatory reaction. The resolving appearence on OsteoGen™ granules could not be recognize.
This formation of new bone seems to be produced by the osteoinductive material BMP in Dembone™ and“osteogenic space” of patient's proper bone.

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Purpose: The prosthetic methods for implantation, 1. connection method of implant and natural teeth abutments and 2. independent method-using implant abutment only, are thought to be determined by various conditions of the defective part in general-use implant types. We researched statisticaly SUMICIKON's and Bonefit's PERIO TEST data on effectiveness of connection to natural teeth.
Method: We measured (average and standard deviation) from just after operation to 600 days after implantation. And we measured natural molar teeth which were used as controls.
Result: 1. natural teeth: 6.93 (n=132 persons × 4 type teeth × 4 blocks=2112, S.D.=0.87) 1) first premolar: 5.83, 2) second premolar: 7.06, 3)first molar: 5.92, 4)second molar: 8.93
2. Implant (n=247): 1)SUMICIKON:6.00 (n=42, S.D.=0.94), 2)Bonefit: 0.36 (n=205, S.D.=0.66)
Consideration:1. Natural teeth connecting bone growth and implant bone growth conditions and 2. adjacent and antagonistic teeth conditions are thought to be most important for Perio Test values related to connection and independent methods for natural teeth. This time we took 1. into consideration.
In case 2 molars are defected in blade-type implant, Bonefit prosthetic method for wide clinical application is generally the method for premolar 2-abutment. The desirable connection is thought to be an implant abutment of Perio Test value of 5.83＜X＜8.93, if the ideal Perio Test value of the implant abutment is X, from the result of natural teeth.
Conclusion: If Perio Test values are limited, 1. SUMICIKON is the optimum implant for the natural teeth-connecting prosthetic method while the stress concentration of the implant neck section is dangerous in natural teeth connection of 2. Bonefit.

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Implant surgery is accompanied by pain, fear and discomfort which put patients under stress both physically and mentally. The psychosedation such as N₂O inhalation and intravenous sedation have been applied to solve this kind of problem.
However, as for N₂O inhalation, the effect of sedation varies slightly from case to case and the duration of sedation is so short that nasal mask must be continuously used. On the other hand, intravenous tranquilizer, such as Diazepam, may harm the blood vessels and has a rebound side effect. And Flunitrazepam, which has a long action period, does not suit the implant surgery of which operation time is relatively short.
The author has applied the intravenous sedation with Midazolam which has a reliable sedation effect, less harm to blood vessels and surrounding tissues, and short action period.
The author succeeded in solving the problem by applying easily adjustable N₂O inhalation with intravenous sedation with Midazolam to adjust the timing of intravenous sedation in order to match the peak of action period with implant surgery.

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There were many bacteria in the air floating dusts. So we tried to measure a number of the air floating dusts (0.3, 0.5, 1, 3 and 5 μm in diameter) in our clinic from 9:38 to 15:53 the 27th April,1992. We used the HEPA unit with the HEPA filter in order to decrease the air floating dusts in an enclosed room. This HEPA unit has a characteristic of taking off more than 99.97% air floating dusts (over 0.3 μm). We could expect the effect of taking off air floating dusts in the enclosed room.When we measured them there, one person was sitting in the doctor's chair and another was sitting in the dental treatment unit. From 12:53 to 12:55, two men in this room were moving about.
The results of this examination were as follows.
1. We should use the HEPA unit in an enclosed room.
2. We should use surgical clothes in this room.
3. We should switch on the clean air unit 30 minutes before the implant operation.
4. The more people were in this room, the worse was air pollution there in.
The effects of making a clean room in our dental clinic are very valuable.

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We used an image processing system in the diagnostic method for implant prognosis. Many processes were performed by the image processing software “Ultimage”, which performs quantitative analysis, and by using the 3-D processing software “ Spyglass Transform 2.1(IMI) to obtain data, an excellent effect was given to the diagnosis and patient description.
Then by using this software, the basic process was carried out by using completely processed images (images on 6 sheets of dental film) in the quantitative analysis of bone in SUMICIKON double-headed intervals as performed in report 2.
The results of the experiment were very clear and revealed“ Bone remodeling between heads.” Those results agreed exactly with report 2, in which Ultimage of the same image data was used.

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Newly tailored artificial roots made of dense hydroxyapatite were applied clinically and artificial roots of connective tissue attachment type were used. The subjects were healthy adults who visited our hospital. They consisted of 16 males and 20 females, from 27 to 65 years old, with partially edentulous dentition sites. The follow-up duration was 6～23 months. The clinical evaluation was made by macroscopic findings on peripheral gingiva of the artificial root, radiographic findings, and observation of the functional state in mastication. Among the cases treated, there were four cases in which reimplantation were made, after which satisfactory results were obtained.
Adhesion to the epithelium of Hydroxyapatite (HAP) is so superior that gingival infection can be satisfactorily prevented through attention to oral hygiene as well as avoidance of postoperative occlusal pressure on the roots. However, for success of the above-mentioned procedure, attention must be paid to various interoperative and postoperative treatments so as to avoid infection around artificial roots.

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Implantation of the Bioceramic sapphire implant® into the jaw has been very available in clinics.
But, unfortunately the success rate of this implant does not seem to be high in comparison with osseointegrated type implants. So we paid attention to the characteristic biocompatibility of the hydroxyapatite(HA) and devised the HA-coating on the surface of the screw grooves of the Bioceramic sapphire implant®(Apatite-coated Sapphire).Therefore, the purpose of this investigation was to observe the effect of HA-coating under the light microscope during an experimental study with dog mandibles. Microscopically, the HA-coated grooves of the screw was in contact with regenerative bone. In contrast with the grooves, the bare thread of the screw did not appear to be in contact with bone tissue. The results indicate that stability and success of Apatite-coated Sapphire may be possible.

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In this experimental study using adult Shepherd dogs, we examined whether the periotest values (PTVs) represent the interface between implants and regenerative bone or not.
1. PTV
PTVs of all ITI-Bonefit® were almost the same and the mean was -4.5. PTVs of all Cherchève implants showed the mean of ＋5.5. PTVs of BIOCERAM® -Porous implants were very divergent and the mean was ＋1.4 (maximum 25.2, minimum-5.0).
2. Histological Inspection
In some cases of ITI-Bonefit® and Cherchève implants, bone was resorbed very hard at the neck region. But the implants were in contact with regenerative bone. In particular, a BIOCERAM®-Porous implant was surrounded by soft tissue, showing the maximum PTVs of-25.2. By histologically sampling a part of implants were found to be in contact with regenerative bone showed a decrease in PTV. In particular, BIOCERAM®-Porous implant formed a regenerative bone ingrowth into the pore, and the mean of PTVs was -2.1.

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The purpose of this investigation was to evaluate the usefulness of lyophilised dura mater “LYODURA^®” for guided tissue regeneration instead of expanded polytetrafluorbethylene (e-PTFE) or Millipore filter^® membrane. 29 submergible osseointegration implants (20 cases) were placed in boneless areas of human maxilla and mandible.
6 months later, during secondary surgery, the result was evaluated. The 26 implant sites showed bone regeneration.
3 implants were removed.
LYODURA^® can be substituted for e-PTFE or Millipore filter^® as membrane used for guided tissue regeneration. Osteogenesis in humans is possible by maintaining osteogenetic or osteophilic space.

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The purpose of this study was to evaluate the procedures for improving the maxillary alveolar ridges with the flabby tissue, which dislodge remarkably under stress, by the application of hydroxyapatite granules (HAP).
The splints, which adapted to the ridge with an adequately designed contour on the plaster models, were prepared for fixation of the ridge with HAP immediately after operation. The effect of HAP application in two edentulous patients were examined by using the following means, and two kinds of splints, with and without holes as the guides to pack HAP, were compared.
1. the contour of the plaster models.
2. the denture mobility by Mandibular Kinesiograph(M.K.G.).
3. the amount of muscle activity of the masseter by electromyography(E.M.G.).
4. the dietary records and the questionaire on the masticatory ability by using the classification of food by stiffness.
5. the condition of the mucosal tissue covering the ridge with HAP by reflectance spectrophotometry.
The following results were obtained.
1. By application of HAP, the ridges become enlarged and useful in supporting an occlusal force. Thus, the mobility of the dentures was reduced and the masticatory ability was improved.
2. The use of bladed teeth increased the efficency of mastication.
3. The property of mucosal tissue covering the ridge with HAP as the substitutional bone was regarded to be the same one as covering the ridge with natural bone.
4. The splints with the holes were more useful for precise operation of HAP application than the one without holes.
5. The flabby tissue might disappear by only applying HAP, even if it is not surgically removed.
The application of HAP is useful to improve the maxillary alveolar ridge with flabby tissue.

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We clincally studied the method of the application of hydroxyapatite granules (HAP) for improving the maxillary alveolar ridge with flabby tissue.We already reported the way of thinking, procedures and results concerning HAP application in three patients.
For the initial fixation of the ridge with HAP, we anchored the splint to the zygomatic process, but this method had some problems.
The purpose of the present study was to evaluate a new method for improving the initial fixation to lessen the patient's pain.
This time we tried to fix the ridge with HAP by using Druckfender' in a patient, which presses the upper and lower dentures against the respective ridges.
The effect of this method on the initial fixation of the operated area was evaluated radiographically, morphologically, phisiologically, etc.
The new method had the following advantages in comparison with the old method.
1. The operation without general anesthesia.
2. The fixation without infection caused by surgical treatment.
3. The treatment with less pain.
4. Easier observation and treatment at the time of follow-up examination.
For the results of observation and comparison, it was suggested that the method for connecting the splint with the lower denture by using Druckfender' could be useful for the initial fixation of the operating area in edentulous patients.

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Until now, the evaluation after an implantation has not been established clearly.
Therefore, with regard to the peri-implant tissue,we performed the radiological parameter observation (AL-equivalent)and the periodontal parameter observation (probing pocket depth and probing attachment level).
In this study, we examined 21 ITI (Bonefit^®) implants which were placed in 9 partially edentulous patients. 3, 6, 12 and 18 months following implantation, we examined three parameters. We computed the average and SD of the three parameters and examined the data of the parameters by a simple regression analysis.
Therefore, we found that a correlation existed between AL-equivalent and probing attachment level, and we concluded that measurement of the probing attachment level is an important parameter for the evaluation of implant success in long-term studies.

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Using the quantitative analysis of dental radiograms by means of AL-equivalent Images, we can observe easily the progress of clinical cases. Therefore, we compared the inserted Al₂O₃ (Bioceram^®) implants with Ti (Bonefit^®) implants by the AL-equivalent Images.
11 male and 12 female partial edentulous patients, who were treated with A12O3 (Bioceram®) implants, and 5 male and 14 female partial edentulous patients, who were treated with Ti (Bonefit®) implants, were examined in this study.
Dental radiograms were pictured before the implantation and 1, 6, 12 and 18 months following implantation.
We observed the alveolar bone which was between implants or implants and natural teeth, which were the lower half of the implant, equivalent to the alveolar bone which was between the 1 st and 2nd mandibular molars.
The average and SD of the computed AL-equivalents varied by age and between male and female.Thus, a Z-score was used for normalization of these variations. We tested the difference between each group by the t-test.
In this study we observed Al₂O₃ (Bioceram®) implants and Ti (Bonefit®) implants, and we found that after implantation the observed bone of both types of implants was high AL-equivalent. But the AL-equivalent of observed bone of Ti (Bonefit®) implants returned to the state before implantation soon.

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The progress of patients treated with the 2-piece hydroxyapatite implant (Apaceram® 2-Piece Implant, Pentax, Tokyo, Japan) in our clinic has been followed regularly by a standardized radiograph and digital image processing. The radiological examination, which has been demonstrated in this journal by us, is useful for evaluating quantitative bone changes after the implant placement. We observed chronological changes of both marginal bone height and bone density around the implant about two years after the implant placement.33 Apaceram implants were placed in the mandibular molar regions in 13 patients. The mean follow-up period was three years.
1. With regard to chronological changes of marginal bone height, the radiographic results were divided into three groups:type I in which the position remained constant or increased with time course, type II in which the position decreased gradually after the superstructure placement, and type III in which the position decreased rapidly after the abutment placement. The mean changes of the bone height in the Groups I, II, and III amounted to 0.1 mm, -0.4, and -2.4 mm/year, respectively.
2. Bone density around successful Apaceram implant increased clearly. The aspect looked like the bird wing between the implant. The degree of bone change during several months after the abutment placement was larger than that of both during one year after the period and during 6 months after the fixture placement. The lower preoperative bone density was, the more bone density increased.
We evaluated the above results as radiological examination for two years after the implant placement. Our results indicated that the bone resorption/formation around the implant might be related in the occlusal force, and adequate occlusal force should be produced on the implant during each phase following the implant placement.

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To clarify whether or not direct bone interface of two-stage plasma-sprayed hydroxylapatite-coated implant could be achieved by nontapping insertion and this interface could also be maintained following functional loading, clinical and histologic studies were performed using monkeys. All hydroxylapatite-coated implants were clinically neither mobile nor rotated at all. Peri-implant gingiva seemed to be clinically healthy. Direct bone interface was observed and well-maintained after 6 months of loading.

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A case of subperiosteal mandibular osteomyelitis and its clinical treatment are presented. Osteomyelitis was suspected to have been caused by dental implant surgery. The patient showed severe bone resorption of the temporomandibular joint, mandibular muscular process, and mandibular ramus after dental implant surgery. To treat the osteomyelitis and save the implant, decortication,continuous arterial infusion of antibiotics, irrigation of the postdéblidement dead space with antibiotics and intravenous antibiotic chemotherapy were carried out. This case report demonstrates the risk of dental implant surgery as a cause of subperiosteal mandibular osteomyelitis, and describes the basic treatment principle of subperiosteal mandibular osteomyelitis caused by dental implant surgery.

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This report describes the development of bioactive glass ceramic particles and evaluates their use in experimental studies and clinical applications.
1. A preliminary investigation with dogs showed an early initiation of bone formation between glass ceramic particles implanted under the periosteum.
The newly formed bone developed to fill gaps between the glass ceramic particles, indicating the effectiveness of glass ceramic particles in bone restoration.
2. The subjects for the present evalution were 8 cases of atropic mandibular alveolar ridges,12 impacted teeth, and 17 intramaxillary cysts(including radicular cysts).
3. The results were classified as effective, satisfactory, ineffective, and harmful. A very high proportion, 33 or 89.2%, were judged effective or satisfactory.
4. None were evaluated in the harmful category, indicating the safety of the present material.
Among the ineffective cases, there were open wounds due to infection, leakage of the implanted material, and fistula. In case where inflammation had not disappeared at the implantation site due to infection, there were cases where the particles had to be completely removed. It was determined that this was not due to the material, but possibly due to the surgical procedures, as there were no further complications with retreatment.
5. From the above results, it is concluded that the bioactive glass ceramic material is useful as an artificial bone substitute in atrophic mandibular alveolar ridge surgery.

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Proper positioning of the implant is one of the most important steps in the successful apatite 2-piece implant therapy;therefore, the following method using the pilot hole (PH), as a guide for placement, has been used in our clinic for the past four years. First, the direction and position of the implant are determined by using a diagnostic denture and the PH is made in the center of implant site. After several weeks, the implant is positioned according to the determined direction and position.
The validity of this procedure has been already demonstrated. The effects of the PH preparation on the bone tissue, however, is not well-known. The purpose of this investigation is to examine the effects of the PH preparation on the bone tissue by a histological technique.
Seven patients were used as subjects. The PH was prepared at various durations of time, such as 2, 4, or 8 weeks, beforehand. Some of them were prepared at the implant placement. Fifteen pieces of bone column with PH in its center were obtained therefrom. These were fixed in 10% neutral buffered formalin, dehydrated, and embedded in paraffin. Partial serial sections were observed under a light microscope.
In the specimen with the PH prepared several weeks beforehand, numerous newly-formed bone tissues surrounding the old bone trabeculae in the spongy bone area around the PH were observed. On the other hand, in the specimen with the PH prepared at the placement, only slight and thin trabecular bone was observed.
These findings indicate that the surrounding bone tissue was increased by the PH preparation. It is suggested that this expansive bone formation may be advantageous for obtaining higher probability of good ankylosis between the implant surface and bone.

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SCANORA^® is a multimodal radiography system which provides multilayer cross-sectional tomography of dentomaxillary region in easy operation.
Cross-sectional images of dry mandibles with (position) indications were taken by SCANORA^®. These images showed buccolingual morphology accurately. Measurements of bone height and width have no difference between the cross-sectional image and the dry mandible. Defining the cross-sectional tomographic imaging layer, which is based on the panoramic image, was accurate and repeatable.
Clinical experience showed that the cross-sectional tomography provided useful information for the implant treatment.

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The Osseointegrated Implant System was indispensable for many kinds of parts, such as transmucosal meso-structure or superstructure. They were fastened by a screw. The fastening force had an influence on the load of the bite force, accuracy of the superstructure, and prognosis of the implant. Therefore, in this study, we measured the optimum fastening torque force, by using a torque wrench.
The results obtained were as follows:
1. The clinical optimum fastening torque force for the impression post, IME, and superstructure was 4.5 Ncm.
2. The newly devised measuring system was easy to use and repeatable. It should be valuable for measuring the fastening force for various implant systems.

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As for a preoperative and postoperative examination of X-ray radiography for dental implants, the evaluation for standard X-ray photography of the second metacarpal bone is necessary. At that time, forty male and female dental patients in their 20 s were examined on the parameters of bone thickness, bone mineral content and bone density at the two distal portions a and b of the second metacarpal bone shaft. The following results were obtained.
1. The parameters of bone thickness D increased gradually, as the examination points drew nearer from the middle of the bone shaft to the distal portion. It increased more significantly,(p＜0.01) 12% and 35%, at the distal portion a and b than at the middle of the bone shaft m. As the examination points neared the distal portions, the parameters of cortical thickness d₁ and d₂ and combined cortical thickness 2 C decreased significantly (p＜0.01). However, the medullary thickness d became significantly (p＜0.01) wider, 55% and 236%, at the distal portion a and further distal portion b.
2. The parameter of MCI(BN) decreased as the examination points approached the distal portions, and it showed 0.60 at the middle of the bone shaft m, 0.45 and 0.30 at the distal portions a and b, no difference was recognized between the parameters on the examined portions for MCI (GR). The distal portion b for the parameter of cortical area CA increased significantly,(p＜0.01) 12%, larger than the middle of the bone shaft m.
3. The bone mineral contents at h₁, h₂, GSmax and GSmin decreased gradually as the examining points were changed to further from the middle of the bone shaft (p＜0.01), but the differences of decreasing rate for the parameter of h₁ and h₂ and GSmax and GSmin did differ greatly between the two parameters.
4. The parameters of bone mineral contents at BMC and E decreased gradually as the examined points went away from the middle of the bone shaft,but no difference was observed between the portions for the parameters of tBMC.
5. A decreasing rate of the bone mineral content was the largest value of GSmin.
From these results, in evaluating the bone thickness, bone mineral content and bone density of the second metacarpal bone shaft, it is necessary to think of not only the parameters at the middle of the bone shaft but also that at a and b portions.

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To look into the quality of life (QOL) of those who have received dental implants, a questionnaire survey was conducted on a total of 280 male and female patients. The results of the inquiry are as follows:
1. The available recovery rate of the quenstionnaire was 70.4%. In the total number of the valid reply cards, 33.0% were from men and 67.0% from women. The age of the respondents averaged 50.9 and the number of years after implant operation 4.8. Regarding implant sites, the lower jaw 1.6 times as many as the upper jaw. Especially, mandibular molars were predominant. Half of the implant materials were metal.
2. Pain, a feeling of physical disorder, a sense of mental unease, emotional stress of the treatment received, melancholy, and a feeling of uneasiness on the job were not cited as their major complaints. On the contrary, a majority said that they can sleep well, have a good appetite, have no difficulty in masticating, and felt the medical staff are dependable and treatment is satisfactory. The respondents' relationships with other members of the family were found generally quite good; however, many of those who said that they want to revisit the dental clinics for treatment confided that the medical cost is a heavy burden for them. Those who have told their family and friends about dental treatment were relatively few in number.
3. When the QOL of the implant patients were examined in light of three elements, physical, psychological, and social, sensitivity to the social element was less significant than the physical and psychological elements.
4. It was found that the pain in implanted regions and the feeling of physical disorder are associated with a sense of mental unease and melancholy, while appetite and mastication are related directly with sleep and indirectly with anxieties on the job.
As indicated above, the QOL of the patients who received the implants has been fairly good. To maintain or further upgrade the QOL, thorough management of ex-patients and follow-up surveys are considered necessary. The present investigation also suggests that measures be taken to take care of those who are not satisfied with treatment results.

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Bioceram Porous Implant made with alumina was developed by Kyoto Ceramic Company and has been approved for implants.
We have used Bioceram Porous Implant in our clinic since September 1984. For 8 years and a half, we observed the process of 65 implants in 60 subjects. Herein we report about the prognosis of Bioceram Porous Implant. Most of the 61 implants in 56 subjects (18 men and 42 women;aged 20 to 70) have progressed satisfactorily after the operation. And we think that the cause of satisfaction is the quality of maintenance after the operation, but one implant had to be removed because of infection after setting the crown.
We thought that it was caused by the contamination of the biocomposite surface of the implant above the alveolar bone. And 3 implants in 3 subjests were broken. Although this is unusual, we thought it was caused by the ratio of the length of the part in the bone to the length of the part over the bone and fatigue of the implant inflicted by occlusal load for a long term.

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