A questionnaire survey was conducted by mail to 89 patients (42 males and 47 females) who had endosseous implants for over two years.
The questions were as follows:
1. Reason for choosing dental implant
2. Previous experience with dentures
3. Comparison with previous dentures
4. Reason for being comfortable with implants
5. Reason for being uncomfortable with implants
6. Degree of satisfaction with implants
7. Expected duration of implants
8. Condition of implanted portion
9. Desire for reimplantation
10. As implant fee
11. Types of food that can be chewed
They were also asked to write any comments. There were responses from 54 people (61%). Most of them were satisfied with implants, especially those who previously wore dentures (91% of those who responded). Most of them felt comfortable eating, talking, and taking care of the implant. On the other hand, there were many who stated that it was difficult to brush and that they had to visit the office frequently.
Most of them decided to have implants due to the recommendation of their dentist. They wanted the implant to last 20 to 50 years. 70% wanted reimplantation. According to the chewing scale obtained from chewable foods, 50% said they were table to chew most foods.
It was generally acknowledged that implants were beneficial but many complained of the high cost of treatment, uncertainty of length of guarantee, length of treatment period and number of visits, pain and uneasiness during treatment period. There were complaints of trouble accomparying early and removal of the implant.
Continuous monitoring is important during implant placement. Therefore, the Video Overlay Monitoring System (hereafter referred to as VOLMS), which superimposes data obtained from a commercially available monitor onto the intraoperative images from a video camera, was developed. This system allows the storage and transfer of these images. However, the system, can only display the time and vital signs on the intraoperative images.
Software for processing vital information, including recording, comparison, and evaluation of data obtained from the monitor as well as time and other factors, was developed as described below.
1. In addition to systolic blood pressure (SBP), pulse rate (PR), percutaneously measured saturation of arterial oxygen (SpO2), and rate pressure product (RPP), a percentage change from the preoperative value is shown for each variable as an advisory mark.
2. An alarm can be programmed to be triggered at any predetermined levels of SBP, PR, SpO 2, and RPP. Along with alarm sounds, an alarm state is notified on the screen.
3. If an alarm is sounded for any of four variables, the screen automatically switches to list the current and preoperative value for each variable, the upper and lower limits of the predetermined alarm, and a percentage change in RPP as well as the time that the alarm is sounded.
4. RPP graphics are displayed.
5. When an interval between blood pressure measurements is set to two minutes or longer, the PR and SpO2 values obtained from the fingertip probe are displayed once per minute for data interpolation.
6. The time elapsed and the patient's age, sex, and disease history are constantly displayed on the screen.
When used as a support system for implant placement, the VOLMS with the vital information processing functions described above is expected to be very useful in preventing accidents. Especially when the operator is responsible for monitoring the patient's systemic status, this system helps the operator to make good use of vital information from the monitor with a simple procedure.
Five adult dogs were used in this experiment to investigate the usefullness of root tips of the tooth for bone replacement materials and the effect of the GBR technique.
The experimental methods filling of blood clot and filling of root tips of the tooth. In each method, three dogs were treated by the GBR technique and two dogs without membranes as controls.Tissue specimens were taken 1,3 and 5 weeks after operations for observation under the light microscope.
1. In the case of filling of only blood clot, osseous healing was finished 5 weeks after operation,but the top of the socket was kept thick by GBR technique for a long time.
2. In the case of filling of root tips of the tooth,osseous addition occured one week after operation by tips with Sharpey's fibers, and it was found that bone gradually replaced the root tips of the tooth. In the case treated by GBR technique as well as the case of filling of only blood clot, osseous addition and thickness of the alveolar ridge at the top of the socket were observed 5 weeks after operation.
3. The root tips of tooth are useful as bone replacement material and should be used with Sharpey's fibers. The combined use of root tips and GBR technique was recommended according to the formation of a firm alveolar ridge by the GBR technique.
The placement of dental implants in the molar region of the maxilla is often difficult due to the presence of the maxillary sinus. Therefore, the placement of implants in the pillar of bone consisting of the maxillary tuberosity, pterygoid process of the sphenoid bone, and pyramidal process of the palatine bone, which is located at the posterior part of the maxilla, is attempted for maintenance and stabilization of prostheses. In this study, We morphometricaly examined the internal structure of the pillar of bone comparing its changes after missing teeth.
The posterior part of the maxilla, including pterygoid process of the sphenoid bone and pyramidal process of the palatine bone were embedded in polyester resin. Then serial transverse sections with 500 μm thickness were prepared, and soft X-ray photographs were taken. The ante-posterior length, bucco-lingual length and trabecular structure were measured at 3 horizontal planes of the pillar of bone (upper, middle and lower planes) using an image analyzer. Three-dimensional images of the pillar of bone were reconstructed from the contour in the soft X-ray images, and the height, inclination angles and volume of the pillar of bone were measured.
In dentulous specimens, the ante-posterior length was larger at the lower than the other planes of the pillar of bone. At the upper planes, the length under 4 mm was appeared in about 70% of the specimens. The bucco-lingual length was the greatest at the middle planes. The width of trabecular bones was greater at the lower than the other planes. The pillar of bone in the posterior part of the maxilla was inclined ante-posteriorly at an angle of 73.0 ±3.3 degrees from the anterior to posterior direction in relation to the Frankfurt horizontal plane and bucco-lingually at 18.9±1.9 degrees to the medial direction in relation to the sagittal plane.
In edentulous specimens, the ante-posterior length was greater at all planes of measurement than in dentulous specimens, but the length less than 4 mm was observed in about 40% of the specimens at the upper planes. Both the number and width of trabecular bones were smaller at all planes compared with dentulous specimens. The pillar of bone was inclined ante-posteriorly at 61.8±5.5 degrees in relation to the Frankfurt horizontal plane and bucco-lingually at 15.4±1.9 degrees in relation to the sagittal plane. The volume of the pillar of bone was greater in comparison with dentulous specimens.
In a case with pain on chewing movement, a diagnosis of occlusal trauma, caused by occlusal interference on the left lower second molar, was made, because of findings obtained by Sirognathograph Analyzing System Ⅲ and the study model.
Treatments were as follows:
1. Provisional restoration and reshaping of the opposite teeth.
2. Two fixtures were inserted in the missing tooth area.
3. Provisional restoration was done.
4. Diagnosis was made again.
After treatment, the pain disappeared and the periodontal tissue was improved.
The biconTM Dental Implant System is very interesting in that the character of its design is quite simple. The biconTM Dental Implant requires only two parts. The biconTM Dental Implant System's concept is based on the locking taper abutment attachment. This abutment is a one and one-half-degree tapered post that relies on friction. With this system, it is not necessary to use screws and torque drivers.
A retrospective study on the biconTM Dental Implant System was conducted using the results from 1,821 implants which were placed in 284 patients from 1986 to 1995. Only 28 of these implants failed during the observation period. From the investigation of this data, the success rate of biconTM Dental Implant System was calculated to be 98.5% over a 10 year period.
Magnetic attachment retainers, which used SUS 430 stainless steel produced by the machining method, were applied to implant treatment. In a patient for whom a denture was repeatedly fabricated because of its instability and detachment due to marked bone resorption after removal of maxillary subperiosteal implants, the amount of bone was confirmed by CT radiography after healing of bone,and then Integral® implants (right side; 3.25 mm in thickness, 6.0 mm in length, left side; 4.0 mm in thickness, 5.0 mm in length) were implanted into the bilateral molar areas. Magnetic attachment retainers were fixed to the implant fixture. A denture was fabricated by the routine method, and the magnetic alloy of HICOREX SUPER J® (right side; 3515, left side; 4015) was fixed to the inner surface of the denture with self-curing resin. No problems, including detachment of denture, were observed, and the patient was satisfied during denture application.
Porous-coated endosseous dental implants (EndoporeTM Implant) newly developed, with achievements of the MRC program for dental implantology at the Faculty of Dentistry, University of Toronto, Canada, were initially applied to 35 of Japanese patients as a clinical trial in Japan from July, 1994. This implant has a unique surface geometry with powder-sintered bead layers on the surface of the fixture promoting three-dimensional interlocking with bone, and this surface structure leads to reduction of implant length with an increased bone contact area on its surface. It consequently produces firmer bone support of implants.
Partially edentulous cases of the mandible were mainly selected, and 1 to 3 implants (total:78 implants) were placed under a certain surgical procedure previously performed at the University of Toronto.
As a clinical evaluation, observation of the periimplant tissue condition by Gingival Index, measurement of peri-implant pocket depth, measuremeat of implant mobility with Periotest device, and clinical observation of the bone condition around implants with radiographs were performed.
In addition, a questionnaire was given to patients after 6-month function in order to determine the condition of oral function and patient's satisfaction with the implant.
After 6-Month function, 75 of implants have been keeping normal function(survival rate:96.2%), and no abnormal aspect suggesting infection, bone resorption, and implant mobility, which could cause implant failure, was observed.
This implant has many favorable characteristics for clinical application such as a firm bone support with bone ingrowth into a three-dimensional network of pores, an easy placement of the implant fixture by a simple surgical procedure and a downsizing of implant length resulting in application to a wide range of clinical cases compared to former implant systems. They must contribute to spread implant therapy to general clinical practice.
For implant operation, total management of patients was performed by the dentist, dental technician, and dental hygienist in terms of the operation, the fabrication of prosthetic appliances, and post-operative care. Thus dental technicians are included in our discussion from the stage of treatment planning before the operation. As part of this process, two super structures, overdenture (case 1) and bone-anchored full bridge (case 2) were compared.
Integral® Implant (Calcitek Inc., U.S.A.), 3.25 mm in diameter and 8 mm or 10 mm long, and prosthetic materials made by Calcitek Inc. were used in those cases, and the overdenture was made of heat-cure resin (Acron, GC Co., Japan) and artificial teeth (ENDURA, Shofu Co., Japan).
Type IV gold alloy (Panahellaus Inc., Germany) was used for a bone-anchored full bridge.
The results were as follows:
The patients in both cases were satisfied with their prosthetic appliance over the implant, as compared with the conventional denture they used before operation.
It took 50 days in case 1 and 34 days in case 2 to complete the prosthesis.
There was no difference in difficulty of the fabricating process between overdenture and conventional one. The bone-anchored full bridge in case 2, however, costed much more because of its materials for transfercoping than the overdenture in case 1. Consequently, the cost of case 2 was more than three times greater than that of case 1.
In mandibular reconstruction, the nonvascularized autogenous iliac bone graft has been greatly used. However, we have used the vascularized fibular graft since 1987, especially for major mandibular defect, because of its length, the flexibility in shaping the bone using multiple osteotoinies, and minimal donor-site morbidity.
This report presents our experience with a case of oromandibular reconstruction using the vascularized fibular osteocutaneous flap and Branemark implants.
The patient was a 16-year-old male and referred to our hospital with the chief complaint of swelling of the right angle of the mandible. He underwent angle-to-angle segmental resection and immediate mandibular reconstruction using an almina ceramic alloplast, after diagnosis of ameloblastoma of the mandible. However, it was exposed externally in the mental region. Therefore, oromandibular reconstruction using the vascularized fibular osteocutaneous flap was done after removal of the alloplast. Although he acquired good mandibular contour, a full denture was fixed by circummandibular wiring because of the deficient vertical height of the graft. Eight years eight months after the operation, 6 implants were placed bicortically into the reconstructed mandible to improve masticatory function.
An implant-supported overdenture was employed because oral hygiene was difficult to maintain with a bone-anchored full bridge. He was satisfied with both esthetic and functional results, which improved the patient's QOL.
It was concluded that major oromandibular reconstruction can be done successfully using the fibular osteocutaneous flap and Branemark implants. In addition, the bicortical structure of the fibular graft is ideal for inserting implants, which show good primary stabilization.
Clinical evaluation of cases with unfavorable postoperative course after placement of implants at other dental clinics were performed at our department of oral and maxillofacial surgery.
The subjects were ten patients (four females, six males, aged 44 to 76 years), treated at our department from 1992 to 1997. The total number of removed implants were thirty, which were intraosseous implants. Implants were made of the following materials:eleven of alumina ceramic and nineteen of metal. Shape of implants were six of screw type, six of blade type, three of T type, five of pin type and eight of hand-made type. All cases suffered from osteitis around the implants, of which two were complicated with maxillary sinusitis and inferior alveolar nerve palsy. Ten of the fourteen cases, which visited our department, underwent removal of the complicated implants in our outpatient clinic and four were sent to the dental offices at which the implants were placed. It is necessary to establish a trust relationship in order to obtain preoperative informed consent and carry out follow-up after the prostheses is worn.