The International Journal of Oral & Maxillofacial Implants, 03/1991

Light microscopy, and transmission and scanning electron microscopy were used to evaluate osseointegration of extraoral titanium implant surfaces treated by either autoclaving, exposure to ultraviolet light (UV), or radiofrequency glow discharge (RFGD). Ultraviolet and RFGD-treated implants showed faster healing in the initial 5-week to 3-month period. By 6 months of healing, no structural differences were found at the bone/implant interface among the different treatments. It was concluded that UV or RFGD surface treatment of titanium implants may shorten the time interval between placement and loading. Keywords: healing, implants, interface, osseointegration, titanium

The aim of this study was to assess possible adaptive changes in the masticatory rhythmical pattern after insertion of an osseointegrated fixed denture. Registrations of masticatory cycle duration, mandibular velocity, and displacement were performed before and 2 months and 10 years after rehabilitation. No major changes except for a decreased occlusal level phase had occurred regarding cycle duration over the years. However, a significantly higher mandibular velocity and greater displacement were recorded 2 months after rehabilitation. This trend was further established in the long term. Temporal timing of rhythmical chewing seems to be relatively consistent, suggesting that the central pattern generator driving output over time is constant. Keywords: dental implants, dental prosthesis, mastication

A retrospective study was completed to assess the success rate of endosseous cylinder implants placed in mandibles that were 10 mm or less in maximum anterior height as measured from lateral cephalometric radiographs. Only implants that were located anteriorly between the mental foramina and loaded prosthetically for a minimum of 1 year were studied. Twenty-eight patients with a total of 130 Nobelpharma implants (forty-six 7 mm and eighty-four 10 mm) were included. The fixtures were evaluated following standard clinical criteria for success established for implants of this type. A total of 8 (two 7 mm and six 10 mm) of 130 implants failed, yielding an overall success rate of 94%. Major complications encountered included a complete mandibular fracture, a partial mandibular fracture, and a temporary bilateral mental nerve hypoesthesia. Keywords: atrophic, Brånemark System®, cylinder implants, endosseous implants, mandible

A total of 391 edentulous maxillae and mandibles was consecutively treated with routine fixed prostheses, supported by 2,199 implants. The patients were followed for 1 year; the overall success rate was 99.5% and 98.1% for the prostheses and implants, respectively. The number of severe complications was low, but it was possible to identify a significantly higher ratio of problems in the maxillae throughout the observation period than for the mandibles. While many problems occurred in both the maxillae and mandibles, there were also problems more typical for each jaw. Diction and fractures of resin teeth were more common problems in maxillae; cheek and lip biting was a more frequent postinsertion complication in the treatment of mandibles. Most problems were easily resolved, and the retrievability of the prostheses was of great advantage. Keywords: Brånemark implants, complications, edentulism, fixed prostheses

The conventional osseointegration protocol calls for waiting up to 12 months for ossification of an extraction socket to heal before placing an endosseous implant. In this study the possibility of placing a pure titanium implant directly into an extraction socket immediately after extraction was investigated. A pure titanium Nobelpharma 10-mm implant was placed into a central incisor extraction socket of a stump-tailed monkey and allowed to heal for a period of 6 months, followed by functional loading of the implant. The implant was osseointegrated on a clinical and histological level. This pilot study suggests that pure titanium implants have the potential to integrate when placed immediately after extraction of the teeth and warrants further investigation. Keywords: endosseous titanium implant, immediate implantation, osseointegration

The effect of two different treatment modalities on the tissue integration of Frialit implants was compared in an experimental study in 10 monkeys. The maxillary central incisors were extracted. In one extraction site, chosen by lot, a Frialit implant was immediately inserted, allowing the implant to penetrate the oral mucosa. In the contralateral extraction site, a modified Frialit implant was placed and allowed to heal under a mucoperiosteal flap. None of the implants used in the study was loaded during the observation periods. After experimental periods of 1, 3, 6, and 8 months, the implants were evaluated and monkeys were sacrificed. In situ and histological evaluation showed no significant difference between the two treatment modalities under nonloading conditions. In both cases the healing around the implants was uneventful and good tissue integration was achieved. Keywords: ceramic implants, Frialit implants, histology, microradiography, monkey, oral surgery, osseointegration

Fifty-six endosseous cylindrical implants were placed in dog mandibles 12 weeks after the extraction of all mandibular premolars and first molars. Eight implants, four coated with 50 µm of hydroxylapatite (HA) and four grit-blasted and titanium-surfaced, were placed in each dog. Ideal implant placement sites were modified by creating standardized 3 × 5-mm facial dehiscence defects. Half the dehiscences were treated with a modified expanded polytetrafluoroethylene (PTFE) membrane; the remainder served as controls. After 8 weeks of healing, the animals were sacrificed and measurements made to determine the percentage of dehiscence repair. The HA-coated implants had a mean defect fill of 95.17% and the grit-blasted implants had a percent fill of 82.8% in the guided tissue regeneration (GTR) test group; the control implants demonstrated a mean fill of 55% and 39% in the HA-coated and grit-blasted implants, respectively. Significant differences (P .05) were noted between both test groups and the titanium control group, and between the HA test and HA control groups. Histologic evaluation showed significantly greater repair associated with HA-coated implants, as well as significant bone loss associated with clinically exposed membranes. It was concluded that within the limitations of this study, guided tissue regeneration is a viable option in treating defects associated with dental implants. Keywords: guided tissue regeneration, hydroxylapatite-coated implants, titanium implants

Twenty-three patients with Kennedy Class I mandibular dentition were supplied with prostheses in the posterior parts of the mandible. On one side they were given a prosthesis supported by two implants (prosthesis Type I) and on the other side they received a prosthesis supported by one implant and one natural tooth (prosthesis Type II). Sixty-nine fixtures were inserted and 46 prostheses constructed. Eight of the fixtures were lost during the observation period. The failure rate of the implants was about the same in the two types of prostheses; five fixtures belonged to prostheses Type I (10.9%) and two fixtures belonged to prostheses Type II (8.7%), while one fixture was lost prior to loading. From a theoretical point of view, the combination of a tooth and an osseointegrated implant should encounter problems with regard to the difference in bone anchorage and there should be a risk of biomechanical complications. However, the results of this study did not indicate any disadvantages in connecting teeth and implants in the same restoration. Keywords: Brånemark System, combination teeth-implants, endosseous implants, partial edentulism

This study investigated the colonization of teeth and hydroxylapatite-coated dental implants by different ¡groups of oral bacteria. Periodontal and gingival health were assessed and subgingival plaque samples were taken. Bacterial morphotypes in subgingival plaque samples were enumerated and expressed as percent of bacteria counted, and presence of trypsin-like enzymes was detected by hydrolysis of benzoyl-arginine naphthylamide (BANA). For both pooled and separate implant and teeth data, positive correlations were found between pocket depth and both BANA hydrolysis and percent spirochetes, and a negative correlation was found between pocket depth and percent cocci. With one exception, analysis of variance revealed no significant differences between implants and teeth for presence of bacterial morphotypes when considering both periodontal and gingival health. Keywords: bacterial morphotypes, hydroxylapatite coated implants, subgingival bacteria, trypsin-like enzyme

Relative movement and force transmission between osseointegrated (OI) implants in the premolar regions of the edentulous mandible have been measured using intraoral transducers linked to OI implants. These have shown deformations of up to 420 µm and force transmission of up to 16 N as a result of jaw movement from the rest position. Greather displacements and forces were observed in active opening and protrusion than in lateral excursions. There were wide variations from subject to subject, and while the effects of these phenomena are not known, they may be potentially harmful to the interfaces between the implants and bone and the various components of the implant superstructure. Keywords: mandibular deformation, osseointegrated implants

The edentulous maxilla presents, perhaps, the greatest challenge to implant therapy. The anatomic, esthetic, and functional demands for fixed reconstruction of the maxillary arch are affected by many variables, some of which are controllable by the surgeon and dentist. This paper describes those variables and offers suggestions for managing the controllable aspects of treatment while avoiding the uncontrollable ones. Suggestions for planning the surgical and prosthodontic phases of treatment are described. Keywords: dental implants, implant occlusion, maxillary implants, treatment planning

The use of endosseous implants to facilitate orthodontic tooth movement has been periodically reported in the scientific literature for over 40 years. The predictable achievement of rigid bone-implant anchorage was first applied by Brånemark in 1965. Using the osseointegration method, a prospective study was conducted involving seven adult patients who were treated with titanium implants used as rigid anchorage units. Orthodontic forces were directed off the implants to correct a variety of malocclusions. All 14 implants placed remained stable during the course of treatment with loading forces of 150 to 400 g. No significant complications occurred. Desirable occlusal and facial results were achieved in all cases. The results obtained over a 3-year period of treatment indicate that intraoral rigid anchorage in the absence of observed reciprocal action is possible. Keywords: intraoral anchorage, orthodontics, titanium implants

Five titanium caps were implanted in the mandibles of five dogs. Three caps contained Sm-Co mini magnets and two caps were empty. The aim of this study was to determine if implanted magnetic fields had any biological effects on the bone tissue of dogs. At the end of 6 months, the animals were sacrificed and segments containing implants and segments from the side opposite the implants, for control, were removed. Sections were made from the specimens and no pathology was seen upon microscopic examination. Keywords: bone tissue, magnetic field, titanium implant

The use of osseointegrated dental implants has now become an accepted form of dental treatment. An osseointegrated implant can be used to give the prosthodontist that extra support needed to make a doubtful prognosis more predictable. In this clinical situation, the abutment teeth on either side of a four-tooth gap were not considered strong enough to support a six-unit superstructure. Two osseointegrated Core-Vent implants were successfully used to provide the necessary support. Keywords: Core-Vent implant, dental implants, fixed partial prostheses, osseointegration