bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of early placement of a single tooth implant. A case report.
Authors: Johansson G. , Palmqvist S. , Svenson B.
Published: March 2003

A single tooth implant was placed in a boy aged 12 years and 3 months. The case has been followed for more than 4.5 years. The fixture did not move together with the adjacent teeth as the maxillary growth went on. There was no “loss” of marginal bone on the side of one adjacent tooth where the distance between implant and tooth was appropriate. But a “loss” of marginal bone (measured from the cemento‐enamel junction) was noted on the other adjacent tooth where the fixture had been placed 1 too close to the tooth.
Guided bone regeneration in mandibular defects in rats using a bioresorbable polymer
Authors: Kostopoulos L. , Karring T.
Published: March 2003

The aim of this study was to explore the possibility of obtaining bone regeneration in jaw bone defects in rats after coverage of the defects with an occlusive bioresorbable membrane. The experiment was carried out in 31 rats. The mandibular ramus was exposed in both sides and a 2 x 3 mm defect was produced at its lower border. A gutta‐percha point was placed to indicate the original level of the border. The defect on one side was covered with a polyhydroxybutyrate resorbable membrane, whereas the contralateral side received no membrane before closure of the wound. Macerated jaw specimens representing 3 and 6 months of healing demonstrated minimal bone fill in the control defects, whereas all test defects healed to or close to the gutta‐percha point, indicating the original inferior border of the jaw. The histological analysis demonstrated increasing bone fill in the test specimens from 15–180 days, whereas only 35–40% of the defect area in the control sides was filled with bone after 3–6 months. Ingrowth of muscular. glandular and connective tissue was consistently occurring in the control defects during healing. It can be concluded that selective repopulation of bone defects with bone‐forming cells can be ensured by excluding surrounding soft tissues from the wound area with an occlusive bioresorbable membrane.
A histomorghometric study of screw‐shaped and removal torque titanium implants with three different surface topographies
Authors: Wennerberg A. , Albrektsson T. , Andersson B. , Krol J. J.
Published: March 2003

Screw‐shaped implants with 3 different surface topographies, evidenced visually as well as numerically with an optical profilometer. were inserted in rabbit bone. After a healing period of 12 weeks, a statistically significant higher removal torque was needed to unscrew screws blasted with25 μm TiO2 particles and screws blasted with 75 μm particles of A1203 compared with screws with a turned surface. The histomorphometric evaluation demonstrated a higher percentage of bone‐to‐metal contact for implants blasted with 25 μm particles of TiO2 compared with the as‐machined implants. A greater surface area of bone in threads was found for the turned screws compared with screws blasted with 25 μm TiO2 particles. In the short‐term follow‐up, there was a better fixation of implants with an average surface roughness of 0.9–1.3 μm and with a homogeneous surface structure than of implants with an average surface roughness of 0.4 μm and with a clear direction of the surface pattern.
Bacterial colonization on internal surfaces of Brånemark system® implant components
Authors: Persson L. G. , Lekholm U. , Leonhardt Å. , Dahlén G. , Lindhe J.
Published: March 2003

The aim of the present study was to examine the microbiota on the internal surface of the components of 28 Brånemark implants® in 10 partially edentulous patients who had been treated with 1 fixed partial prostheses each. The prostheses had been in function for 1 to 8 years. The fixed prostheses were checked for mobility and removed. The abutment screws were loosened and classified as stable, easily removed or loose. Then, bacterial samples were obtained from the various internal surfaces of the implant system. Estimation and identification of the most predominant species was performed on the blood agar plates. Identification was based on Gram reaction, oxygen sensitivity and biochemical tests. Internal surfaces of different components of the Brånemark implants®, after varying periods of function in the oral cavity, consistently harboured a heterogeneous and primarily anaerobic microbiota. The individual samples showed a great variation. No relation could be seen between type and length of abutment, abutment stability, bone loss and type and number of microorganisms found in the samples. The flora consisted mainly of facultative and anaerobic streptococci, Gram‐positive anaerobic rods such as Propionibacterium, Eubacterium and Actinomyces species and Gram‐negative anaerobic rods including Fusobacterium, Prevotella and Porphyomonas species. There are reasons to suggest that this presence of bacteria is the result of (i) a contamination of the fixture and abutment components during the 1st and/or 2nd stage of implant installation and/or (ii) a transmission of microorganisms from the oral environment during function subsequent to bridge installation.
Immediate transmucosal implants using the principle of guided tissue regeneration. (II). A cross‐sectional study comparing the clinical outcome 1 year after immediate to standard implant placement.
Authors: Brägger U. , Hämmerle C. H. F. , Lang N. P.
Published: March 2003

The aim of the present study was to compare the peri‐implant mucosal conditions 1 year after immediate transmucosal implant placement without or in combination with guided tissue regeneration with the situation after regular placement of transmucosal 1‐stage procedure implants in partially edentulous patients. The test group consisted of 15 patients who required the immediate replacement of 20 teeth with oral implants in combination with guided tissue regeneration. The control group 1 consisted of 6 patients who received 8 immediate implants, without concomitant bone regeneration procedure due to the small size of the extracted roots in comparison to the diameter of the implants. The 20 patients of the control group 2 were randomly chosen from over 150 partially edentulous patients who received implants of the ITI® Dental Implant System according to the standard procedure. Similar favorable clinical parameters were found around the implants of all the 3 groups with low plaque and mucosal indices, similar amounts of recession, pocket probing depths and clinical attachment levels. The immediate implants demonstrated lower frequencies of sites bleeding on probing. The study has established that immediate oral implants are a feasible treatment modality with high predictability.
Non‐submerged implants in the treatment of the edentulous lower jaw. A 2‐year longitudinal study.
Authors: Åstrand P. , Almfeldt I. , Brunell G. , Hamp S.‐E. , Hellem S. , Karlsson U.
Published: March 2003

Non‐submerged ITI Bonefit implants ITI Dental Implant System) were inserted in edentulous lower jaws of 46 patients. The patients were provided with either a fixed prosthesis or an overdenture, and has been followed during a 2‐year‐period. At the 1‐year examination, the suprastructures were removed permitting test of the individual implant stability. Radiographic examinations were performed in connection with the loading of the implants and at the 1‐year examination. In total 216 implants were inserted. 4 implants were lost before loading and 4 during the 2nd year of function, which gives a survival rate after 1 year of 98% and after 2 years of 96%. The mean marginal bone loss during the first year of function was 0.1mm. However, the marginal bone changes had a high degree of variation and four implants showed a severe bone loss. The intention is to follow this patient group with annual examinations during 5 years.
A pilot study comparing screw‐shaped implants. Surface analysis and histologic evaluation of bone healing.
Authors: Lucchini J.‐P. , Aurelle J.‐L. , Therin M. , Donath K. , Becker W.
Published: March 2003

The purpose of this study was to compare surface treatment and bone formation adjacent to 2 screw shaped implants of similar design manufactured by two different companies. The test implants were manufactured by SERF (Decines, France), while the controls were manufactured by Nobelpharma (Göteborg, Sweden). The surface of 3 standard 3.75mm test and 3 standard 3.75mm control implants were investigated by means of scanning electron microscopy SEM, X‐ray micro‐analysis, electron spectroscopy for chemical analysis (ESCA) and surface topography analysis. There was a microscopic difference on the thread design (SEM). Test threads were flat at the edge, while controls appeared rounded at the edge of the threads. Tests and controls were made of commercially pure titanium, with a regular topography. Results of ESCA indicated that the carbon peak for SERF implants was slightly higher than for the Brånemark implants. 5 test and 5 control implants were installed into the epiphyseal head of the femur of 2 ewes using a standardized surgical technique. In order to stain the bone for histologic analysis, oxytetracycline injections were given 17 and 8 days before the animals were sacrificed. The animals were sacrificed 12 weeks after implant placement. Histomorphometric analysis indicated that there was an average bone to implant contact of 68% for the test implants and 61% for the controls. There were no statistical differences between tests and controls. The preliminary results of this pilot study indicated that early bone healing for the 2 screw shaped implants investigated were similar.
The application of resonance frequency measurements to study the stability of titanium implants during healing in the rabbit tibia
Authors: Meredith N. , Shagaldi F. , Alleyne D. , Sennerby L. , Cawley P.
Published: March 2003

The aim of this investigation was to measure the resonance frequency of a number of implants placed in the rabbit tibia at insertion and at predetermined periods thereafter and to correlate the results with histomorphometric measurements made when the animals were sacrificed. Ten mature New Zealand White rabbits were used in the study. Two c.p. threaded titanium implants were placed in the right tibia of each animal. Resonance frequency measurements were made by screwing a small transducer onto a standard abutment mounted on each fixture. Measurements were repeated with the transducer oriented perpendicular and parallel to the long axis of the tibia for all proximal implants 14 and 28 days after placement and in 6 implants additionally at 42, 56, 93, 122 and 168 days after which all animals were sacrificed. Histomorphometric analysis comprised 2 parts; measurement of bone‐implant contact area and height. A significant increase in resonance frequency was observed after 14 (405 Hz ± 234 Hz( and 28 (658 Hz ± 332 Hz) days. The increase in resonance frequency levelled after approximately 40 days and little further change was observed. The variation in bone‐implant contact area was relatively small (1.8–4.9 mm2) and the range of bone‐implant contact heights was also narrow (−1.5–+1.5 mm). Values for resonance frequencies plotted against contact area and height were grouped around 10 kHz. In conclusion, it was shown that resonance frequency measurements can be made at placement and during healing in vivo and changes may be related to the increase in stiffness of an implant in the surrounding tissues.
Immunohistochemistry of soft tissues surrounding late failures of Brånemark implants
Authors: Esposito Marco , Thomsen Peter , Mölne Johan , Gretzer Christiana , Ericson Lars E. , Lekholm Ulf
Published: March 2003

The objective of the present investigation was to characterize the cellular composition of the soft tissues surrounding consecutively retrieved late failures of Brånemark implants. Criteria for implant failure were signs of loss of osseointegration (radiographic peri‐fixtural radiolucency and mobility). The clinical history of the implants did not include adverse symptoms. At the time of retrieval, percussion‐induced pain was experienced at 4/S implants, but no macroscopical signs of inflammation or infection was observed. Immunohistochemistry was applied on 6 marginal peri‐implant specimens and on specimens of deeper tissues associated with the previously load‐bearing implant surface from 8 failed implants, whereas 6 clinically healthy mucosal specimens and 4 hyperplastic biopsies from stable implants served as controls. The immunohistochemical evaluation showed that the soft tissues surrounding failed implants contained a large number of macrophages (CD68), HLA‐DR positive cells, lymphocytes and plasma cells preferentially accumulated towards the removed implant surface. PMNs were a rare finding. Downgrowth of epithelium, in some cases encapsulating the whole fixture, was observed in sections where an intact implant/soft tissue interface was preserved. Healthy control mucosal specimens always contained labelled cells, albeit in a low amount, whereas hyperplastic control samples displayed an intense inflammatory and immunological response with numerous positive cells and PMNs scattered throughout the biopsy. In conclusion, failed implants were characterized by a chronic inflammatory response of the surrounding tissues with macrophages as the predominant labelled cell type, while hyperplastic tissues around stable implants were distinguished by an acute inflammatory process. These findings suggest that an on‐going infection is unlikely to be the etiological factor for the late failures of dental implants examined in this study.
Bone morphogenetic protein‐2 for peri‐implant bone regeneration and osseointegration
Authors: Sigurdsson Thorarinn J. , Fu Earl , Tatakis Dimitris N. , Rohrer Michael D. , Wikesjö Ulf M. E.
Published: March 2003

Recombinant human bone morphogenetic protein‐2 (rhBMP‐2) induced bone regeneration and osseointegration was evaluated in supra‐alveolar peri‐implant defects in 5 beagle dogs. Alveolar bone was reduced 5 mm in height in mandibular premolar areas and the premolars were extracted. Three 10 mm titanium fixtures were placed 5 mm into each reduced alveolar crest, leaving 5 mm in a supraalveolar position. Alternate quadrants in consecutive animals received a surgical implant consisting of 2 ml rhBMP‐2 (0.43 mg/ml) in a type I bovine collagen carrier, or the carrier alone (control). Fixtures and surgical implants were submerged under the gingival flaps. The healing interval was 16 weeks. Histometric and radiographic evaluations were made. Defect height averaged (*SD) 5.3±O.2 and 5.1±0.2 mm for rhBMP‐2 and control defects, respectively (P>0.05, n=5, paired, f‐test) Bone regeneration (height) averaged 4.2+1.0 and 0.5±0.3 mm for rhBMP‐2 and control defects, respectively (P>0.05). Bone regeneration (area) averaged 6.1±6.3 and 0.2±0.2 mm² for rhBMP‐2 and control defects, respectively (P±0.05). Osseointegration within the confines of the defect averaged 19.1±10.1% and 8.2±4.6% for rhBMP‐2 and control defects, respectively (P<O.O5). Osseointegration within regenerated bone averaged 29.1±9.8% and 65.3±15.3% for rhBMP‐2 and control defects, respectively (P<0.05). Osseointegration within the retained alveolar bone averaged 67.1±4.6% and 68.1±3.6% for rhBMP‐2 and control defects, respectively (P>0.05). The results suggest that there is a potential for rhBMP‐2 induced bone regeneration and osseointegration in surgical peri‐implant defects.
Initial interfacial healing events around calcium phosphate (Ca‐P) coated oral implants
Authors: Hulshoff Johanna E. G. , Jansen John A.
Published: March 2003

The bone response to different calcium phosphate (Ca‐P) coated and non‐coated titanium implants was evaluated in a goat animal model. Two types of Ca‐P coatings have been investigated: an experimental plasma‐spray bi‐layered Ca‐P coating (FA‐HA) and an amorphous RF magnetron sputter coating (Ca‐P‐a). Fifty‐four conical screw shaped implants were inserted in the lateral and medial femoral condyles of 18 Saanen goats. After implantation periods of 3, 12 and 24 days, the bone‐implant interface was evaluated histologically and histomorphometrically. Light microscopical evaluation revealed that bone formation on the Ca‐P coated implants proceeded faster. At 24 days higher percentages of bone contact were measured for both Ca‐P coated implants than for non‐coated implants. However, this difference was only significant for the FA‐HA coated implants. On basis of these findings. we concluded that Ca‐P coatings show improved bone response due to an initial difference in bone cell response.
A 2‐year report on maxillary and mandibular fixed partial dentures supported by Astra Tech dental implants. A comparison of 2 implants with different surface textures.
Authors: Karlsson Ulf , Gotfredsen Klaus , Olsson Cecilia
Published: March 2003

In 50 partially edentulous patients, 133 (48 maxillary; 85 mandibular) Astra Tech dental implants of 2 different surface textures (machined; TiO‐blasted) were alternately installed, supporting 52 fixed partial dentures (FPDs). Before abutment connection 2 machined implants (1 mandibular; 1 maxillary) were found to be non‐osseointegrated and were replaced. Another implant could not be restored due to a technical complication. Two FPDs were remade because of technical complications, both because of abutment fractures. Thus, after 2 years in function, the cumulative survival rates were 97.7% and 95.7% for implants and prostheses, respectively. There was no statistically significant difference in survival rate between the 2 types of implants, 100%(TiO‐blasted) vs 95.3%(machined), P=0.24. After 2 years in function, when both jaw and type of implants were combined, the mean (SD) marginal bone loss was 0.24 (0.69) mm. No statistically significant difference in bone loss was found between the 2 tvues of implant after 2 years of loading, 0.04 (0.82) mm, P>0.30.
Bone behavior around sleeping and non sleeping implants retaining a mandibular hinging overdenture
Authors: Naert Lgnace , Gizani Stella , Van Steenberghe Daniël
Published: March 2003

Since 1984 2 implants in the symphyseal area have been used in our center to retain a hinging overdenture. Because this technique was unknown at that time 1 extra implant was installed in between the 2 others and was left submerged (sleeping). The extra implant served as a rescue implant in case 1 of the 2 others would fail. It was the aim of the present report to compare the marginal bone behavior around those sleeping and non‐sleeping implants. Between 1984 and 1987 20 completely edentulous patients were provided with 3 implants (Brånemark system), where from 2 were used to retain a hinging overdenture. Ten years later half of the patients could still be traced. Retroalveolar radiographs were made at the abutment installation and after 10 years. None of the non‐sleeping or sleeping implants lost, at an individual basis, more than 1.6 and 0.7 mm of marginal bone respectively. On average, non‐sleeping implants lost at the right‐ and left‐hand side of the mandible 0.33 and 0.57 mm of bone respectively. However, sleeping implants lost on average 0.16 mm only. Thus non‐sleeping implants lose on average more bone when compared to sleeping implants. Surgical trauma at the abutment connection is believed to be the most plausible cause of marginal bone loss around non‐sleeping implants.
Assessing mineral density in small trephined jawbone biopsy specimens
Authors: Denissen Harry , Eijsink‐smeets Robert , Van Lingen Arthur , Van Waas Rien
Published: March 2003

This study reports the test of the hypothesis that mineral density can be precisely assessed in small trephined jawbone biopsy specimens. Mineral density was measured by dual‐energy X‐ray absorptiometry (DEXA) and peripheral quantitative computed tomography (pQCT). Ten fresh and ten histologically processed specimens, which were not the same, were measured. The coefficient of variations (CVs) for the alcohol stored and the histologic specimens by DEXA were respectively 1.60 and 1.71%. The CVs by pQCT for the total bone density in the alcohol stored and the histologic specimens were respectively 0.07 and 0.16%, for the trabecular bone density 0.69 and 1.04% and for the cortical bone density 0.07 and 0.12%. It was concluded that DEXA and pQCT are precise for mineral density assessment of small trephined jawbone biopsy specimens both alcohol stored and histologically processed.
Single implants in the upper incisor region and their relationship to the adjacent teeth. An 8‐year follow‐up study.
Authors: Thilander Birgit , Ödman Jan , Jemt Torsten
Published: March 2003

The aim of the study was to find out if implant‐supported crowns in the upper incisor region run the risk of coming into an infraoccluded position later in life. Ten adolescents with 15 implant‐supported crowns were included in the study. The age of the patients at the implant surgery ranged between 14 and 19 years. They were followed up during an 5‐year period. No implant loss was observed. A good or acceptable aesthetic appearance at the last observation was found in most subjects. In some of them a change in the vertical position of the implant‐supported crown, resulting in infraocclusion, could be registered, especially in subjects with no incisor contact. Throughout the follow‐up period, only minor loss of marginal bone support was observed at the implants. At the teeth adjacent to the implant, a reduction of the marginal bone level was observed in some patients. Of importance to consider in single implant therapy is that a fixed chronological age is no guidance for implant placement, due to a slight continuous eruption of the adjacent teeth post adolescence. An orthodontic treatment should be performed not only in order to gain space in the implant area, but also to attain good incisor stability to reduce the risk of infraocclusion of the implant‐supported crown. Furthermore, 3 cases will exemplify that infraocclusion also may occur in patients who had received single implants at adult ages.
Predetermined implant positioning by means of a novel guide template technique
Authors: Minoretti Roger , Merz Beat R. , Triaca Albino
Published: March 2003

This paper presents a novel guide template technique for implant placement. In esthetic implant dentistry with its restoration‐driven implant placement as well as in complete‐arch cases with multiple implants, the precise positioning and angulation of dental implants is crucial for achieving the desired prosthetic results. Difficulties in implant positioning may arise especially with grafted jaws resulting from communication problems between surgeon and prosthodontist. This method may alleviate some of the problems common to conventional template techniques, where the drill is usually directly guided by the template. The key idea is to fixate the implant position and angulation by the help of Kirschner wires which are inserted in the alveolar ridge right through the mucosa before elevation of a mucoperiosteal flap. Thanks to this sequence, the template for guiding the wires may be positioned precisely, even on grafted edentulous ridges. After the insertion of the wires, the bone is exposed and the implant cavities prepared with a trephine drill guided over the wires alone or over wires combined with a special guidance cylinder fitting the trephine drill. The method may be combined with different planning and radiological techniques. Since the use of the template is detached from the actual drilling process, the danger of introducing debris of plastic or metal into the preparation site may be avoided. The present technique might be helpful for difficult cases by improving communication between prosthodontist and surgeon and also render additional security to the surgeon with less routine in dental implant insertion.
A histological evaluation of TiO2‐gritblasted and Ca‐P magnetron sputter coated implants placed into the trabecular bone of the goat: part 2
Authors: Vercaigne Suzy , Wolke Joop G. C. , Naert Ignace , Jansen John A.
Published: March 2003

The aim of this study was to investigate the synergetic influence of surface topography and chemical composition of oral implant materials on bone response. For the experiment screw designed implants were used. The implants were grit‐blasted with TiO2 particles. The implants were left uncoated (Ti) or provided with three different amorphous/crystalline Ca‐P magnetron sputter coatings, resp. 0.1 μm (CaP‐0.1), 1 μm (CaP‐1) and 4 μm (CaP‐4), in thickness. The implants were inserted in the medial femoral condyles of 12 goats. Each femur received 2 implants. After implantation periods of 6 and 12 weeks the implants were retrieved and prepared for histological and histomorphometrical evaluation (bone contact and bone mass). The light microscopy revealed that bone response to CaP‐4 and CaP‐1 implants was similar. For example, after 12 weeks, screw threads were almost completely covered with bone. In contrast to CaP‐0.1 and Ti implants, where bone apposition was less pronounced. Histomorphometry demonstrated that the bone‐to‐implant contact for the CaP‐1 and CaP‐4 implants was significantly higher (P<0.05) than for the CaP‐0.1 and Ti implants. This difference existed already after 6 weeks and was even enhanced after 12 weeks. The bone mass measurements revealed that only at 12 weeks CaP‐4 implants had significantly more bone contact inside the screw threads than non‐coated Ti‐implants (P<0.05). Supported by our findings, we conclude that the additional application of a 1–4 μm thick Ca‐P magnetron sputter coating can further improve the healing response to surface roughened oral implants placed into trabecular bone.
Pulsed electromagnetic fields promote bone formation around dental implants inserted into the femur of rabbits
Authors: Matsumoto Hiroyuki , Ochi Morio , Abiko Yoshihiro , Hirose Yukito , Kaku Tohru , Sakaguchi Kunihiko
Published: March 2003

The present study examined the effect of applying a pulsed electromagnetic field (PEMF) on bone formation around a rough‐surfaced dental implant. A dental implant was inserted into the femur of Japanese white rabbits bilaterally. A PEMF with a pulse width of 25 μs and a pulse frequency of 100 Hz was applied. PEMF stimulation was applied for 4 h or 8 h per day, at a magnetic intensity of 0.2 mT, 0.3 mT or 0.8 mT. The animals were sacrificed 1, 2 or 4 weeks after implantation. After staining the resin sections with 2% basic fuchsin and 0.1% methylene blue, newly formed bone around the implant on tissue sections was evaluated by computer image analysis. The bone contact ratios of the PEMF‐treated femurs were significantly larger than those of the control groups. Both the bone contact ratio and bone area ratio of the 0.2 mT‐ and 0.3 mT‐treated femurs were significantly larger than the respective value of the 0.8 mT‐treated femurs (P<0.001). No significant difference in bone contact ratio or bone area ratio was observed whether PEMF was applied for 4 h/day or 8 h/day. Although a significantly greater amount of bone had formed around the implant of the 2‐week treated femurs than the 1‐week treated femurs, no significant difference was observed between the 2‐week and 4‐week treated femurs. These results suggest that PEMF stimulation may be useful for promoting bone formation around rough‐surfaced dental implants. It is important to select the proper magnetic intensity, duration per day, and length of treatment.
Can implants be correctly angulated based on surgical templates used for osseointegrated dental implants?
Authors: Naitoh Munetaka , Ariji Eiichiro , Okumura Shinji , Ohsaki Chiaki , Kurita Kenichi , Ishigami Tomohiko
Published: March 2003

When placing osseointegrated dental implants, the site, angulation and depth of implants can be designed using a computed tomography (CT) or conventional X‐ray tomography. To correctly identify placement pre‐surgically, various kinds of surgical templates have been proposed. Although it is thought to be important to use templates, no material has been published on their accuracy. The purpose of this study was to propose a method for evaluating the placement accuracy using a specific surgical template. Twenty‐one implants were evaluated in 6 patients with mean age of 50.7 years. All implants were implanted by two step surgery in the posterior mandible. A surgical template based on the CT images and the abutment replica on the working models were used for the evaluation of the accuracy of implant placement. The difference between the proposed and actual directions was measured by a milling machine. The difference in the angles between the proposed direction and actual direction were from 0.5 degrees to 14.5 degrees. The average was 5.0 degrees, and there were 12 implants (57%) within 5.0 degrees. This study demonstrated the accuracy of the template described in this article.
Maxillary sinusfloor elevation and grafting with human demineralized freeze dried bone
Authors: Van Den Bergh Johan P. A. , Ten Bruggenkate Chris M. , Krekeler Gisbert , Tuinzing D. Bram
Published: March 2003

In the continuous search for the ideal grafting material in this study the authors used human demineralized freeze dried bone (DFDB) in the maxillary sinusfloor elevation surgery. In total 30 sinusgrafts were performed in 24 patients. Residual lateral maxillary bone height was less than 8 mm but more than 4 mm. The surgical technique used was according to the description of Tatum (1986). In those 30 grafted sinuses a total of 69 ITI full body screw implants were placed 6 months after grafting. Four sinuses exhibited a prolonged healing time. All implants were loaded 4 months after insertion. No implant losses or failures occurred. The rough surface ITI dental implant appeared to be a suitable implant following sinusgrafting with DFDB. According to the results of this study the limited sinusfloor elevation procedure with DFDB appears to be a clinical reliable pre‐implant procedure.
Clinical analysis of implant losses in oral tumor and defect patients
Authors: Kovács Adorján F.
Published: March 2003

In the period between 1990 and 1996, 279 endosteal dental Bone‐Lock implants were placed in 79 patients. Of them 63 have been treated with ablative tumor and reconstructive surgery in the oral cavity, the rest presented with maxillo‐mandibular defects of different origin. The circumstances of implant loss were noted down for descriptive analysis concerning age, sex, topography, implant dimensions, loading, time in place and type of superstructure. Failure analysis was done concerning the implants and the patients. Five causes for implant loss could be detected: lacking primary osseointegration, acute inflammation, bone loss, biomechanical overloading and tumor recurrence. No predictive factors for implant loss and no age influence on implant loss could be detected, no specific local implant site and no specific superstructure had an identifiable higher risk. Survival rate of all placed implants in oral tumor and defect patients was 83.5% after 6 years observation. Male tumor patients were found to have a higher risk to lose implants than females. Free iliac bone grafts impaired osseointegration of implants. The mandible offered a better prognosis for the implants than the maxilla. Shorter and thinner implants had a higher risk of being lost. A quarter of all patients (26.3%) had to face implant loss. Clustering of implant loss in several patients was caused by free iliac bone grafting and by prosthetic faults. Chemotherapy had no negative influence on implant survival. Most implants were lost early (76%) before fabrication of the prosthesis. After restoration there was a nearly 100% probability of function. It is concluded that implant treatment can be equally effective for tumor and defect patients as it is known for healthy subjects.
Clinical outcomes of three Parkinson's disease patients treated with mandibular implant overdentures
Authors: Heckmann Siegfried Martin , Heckmann Josef Georg , Weber Hans‐Peter
Published: March 2003

Parkinson's disease (PD) often affects the oro‐pharyngeal musculature, leading to problems with speaking, chewing and swallowing. The inevitable reduction in food and fluid intake contributes to the further deterioration of neurological symptoms. Parkinson's disease patients have great difficulties in adjusting to the use of complete dentures. It is the purpose of this report to evaluate the benefit of using dental implants combined with overdentures to improve chewing and predigestion capacity in severely handicapped PD patients. Three edentulous PD patients (2 male, 1 female; mean age 75.7 years; mean PD duration 4.3 years; PD severity grade III according to Hoehn and Yahr; mean edentulousness 19.3 years) complaining of poor chewing ability were included in this evaluation. One‐stage dental implants were placed in the interforaminal region of the mandible. After completion of healing, new overdentures were fabricated. Custom‐made non‐rigid (resilient) telescopic attachments were used for retention of the overdentures on the implants. Follow‐up examinations of the 3 patients were made between 28 and 42 months after the completion of treatment, and peri‐implant tissue conditions as well as the patients' self‐assessed satisfaction level were recorded. A modified gastrointestinal symptoms questionnaire, Hoehn and Yahr Scale and body weight measurements were used to monitor gastrointestinal impairment and PD severity. The peri‐implant parameters indicated healthy soft tissue conditions and all Periotest values were in the negative range. The patients judged their chewing abilities to be greatly improved. Since placing the implants, PD severity had deteriorated to grade IV (Hoehn and Yahr scale) in 2 patients and was stable in 1 patient. The body weight had improved slightly in all patients (mean 2.2 kg). On the gastrointestinal scale, all patients had improved from a mean score of 8.7 to 5.7. Non‐rigid telescopic attachments for overdenture stabilization are particularly suitable for PD patients as they are easy to handle and to clean. The patients reported remarkable improvement in their chewing ability, an assessment which would seem to be supported by the improved gastro‐intestinal index. The regimen described appears to be a useful adjunctive treatment in edentulous Parkinson's disease patients and may be considered for patients with diseases similarly affecting motor skills.
Treatment of fully edentulous patients with ITI implants Note
Authors: Weingart Dieter , Ten Bruggenkate Christiaan M.
Published: March 2003

The use of ITI implants for rehabilitation of the edentulous patient has shown predictable results not only in the standard sites but also in cases of advanced alveolar ridge atrophy. Preoperative analysis, including clinical and radiological evaluation, implant selection, and determination of implant number and distribution in the edentulous maxilla and mandible, is described in this article. The surgical procedures used in standard sites are presented, the benefits of a nonsubmerged surgical approach in these cases are emphasized, and a protocol for postoperative management is recommended. Augmentation procedures in advanced osseointegration surgery call for submerged ITI implants when a simultaneous approach is chosen. Several types of advanced implant surgery that can be used are described, including membrane technique, sinus lift procedures, vertical ridge augmentation with iliac bone grafts, and correction of sagittal jaw relationship.
Pain and instability during biting with mandibular implant‐retained overdentures
Authors: Fontijn‐Tekamp F. A. , Slagter AD. P. , Van’t Hof Martin A. , Kalk Warner , Jansen John A.
Published: March 2003

Abstract: We tested in a randomized controlled clinical trial the effect of pain and instability of dentures on bite force with different degrees of mucosal support. The trial involved 3 groups who had received: 1) a new conventional denture (CD‐group), 2) an implant‐mucosa‐borne overdenture on 2 IMZ implants (IMZ‐group) or 3) a mainly implant‐borne overdenture retained by a transmandibular implant (TMI‐group). Fifty‐three women and 15 men, mean age 59 years, participated in this study. Bite force measurements were made unilaterally with a transducer and bilaterally with a bite fork. After the measurements, subjects were asked whether or not biting had caused pain or tilting of one of the dentures. Significantly more complete‐denture wearers reported pain. They reported more frequent pain in the mandible than in the maxilla (P<0.001), whereas implant‐groups seemed to experience more often pain in the maxilla. On the transducer, maxillary dentures of the CD‐group tilted less (P<0.01) and mandibular dentures more (P<0.05) compared to the implant‐groups. With the bite fork, tilting occurred more often in the incisal‐cuspid area than in the molar region (P<0.001). No effect of pain and tilting was observed on maximum bite force. It appears that oral implants used to stabilize mandibular dentures permit subjects to exert higher bite forces and reduce the pain as otherwise felt in the mandible during maximum biting. Due to this stabilization, pain and instability of the maxillary denture can become the limiting factor for a further increase in bite force.
Inhibition of cyclooxygenase by indomethacin modulates osteoblast response to titanium surface roughness in a time‐dependent manner
Authors: Sisk Marc A. , Lohmann Christoph H. , Cochran David L. , Sylvia Victor L. , Simpson James P. , Dean David D. , Boyan Barbara D. , Schwartz Zvi
Published: March 2003

Abstract: Prostaglandin E2 (PGE2) and transforming growth factor‐beta1 (TGF‐β1) production are increased in cultures of osteoblasts grown on rough surfaces and prostaglandins are involved in osteoblast response to surface roughness. In the present study, we examined the effect of inhibiting cyclooxygenase on this response. MG63 osteoblast‐like cells were cultured on cpTi disks with Ra values of 0.60 μm (PT), 3.97 μm (SLA), and 5.21 μm (TPS) in the presence or absence of 10−7 M indomethacin. Treatment was begun on days 1, 2, 3, or 4 after seeding, and all cultures were harvested on day 5. Indomethacin decreased PGE2 release by the cells to less than 50% of basal levels when the cells were cultured on plastic. Cell number decreased with increasing surface roughness and indomethacin treatment abrogated the surface roughness effect over time. Alkaline phosphatase specific activity (ALP) increased with surface roughness; after one day with indomethacin, ALP was decreased on smooth surfaces, but increased on rough surfaces. Over time, ALP decreased on all surfaces examined and remained greater than plastic only in cultures on TPS. Indomethacin also caused a time‐dependent decrease in osteocalcin production on rough surfaces, eventually abrogating the increases due to surface roughness, but had no effect on osteocalcin production on smooth surfaces. TGF‐β1 levels in the cell layer and media were sensitive to surface roughness; on rougher surfaces, TGF‐β1 shifted from the media to the matrix. Indomethacin reduced TGF‐β1 levels over time, but the surface roughness effect was still evident at 4 days. This indicates that prostaglandin production mediates the effects of surface roughness, since indomethacin causes a time‐dependent abrogation of the response, but has no effect on proliferation, osteocalcin release, or TGF‐β1 levels on smooth surfaces. Indomethacin’s effect was not immediate, suggesting that clinical protocols could be designed that would reduce inflammation without preventing osteoblastic differentiation. The effect of indomethacin was not complete, since TGF‐β1 and ALP remained elevated on rough surfaces, suggesting that pathways or factors other than prostanoids are involved. TGF‐β1 is preferentially stored in the matrix, acting on the cells through autocrine signaling, and may contribute to ALP even in the presence of indomethacin. These results demonstrate the importance of local factors in the autocrine regulation of osteogenesis and the potential for factors released in response to surface morphology to act in a paracrine manner.
Clinical and microbiological evaluation of ligature‐induced peri‐implantitis and periodontitis in dogs
Authors: Nociti Francisco H. , Cesco de Toledo Ricardo , Machado Maria A. N. , Stefani Cristine M. , Line Sérgio R. P. , Gonçalves Reginaldo B.
Published: March 2003

Abstract: The purpose of this study was to evaluate the attachment loss around teeth and implants by clinical and microbiological analysis. The mandibular premolars were extracted in 5 mongrel dogs and, 3 months later, two titanium implants were installed on each side of the mandible and, after another 3 months, abutment connection was performed. Plaque control in the implants and maxillary premolars was maintained for two weeks prior to the start of the main experiment. On day 0 and 30 days after ligature placement, microbiological samples were obtained and relative attachment level was measured for the teeth and implants. The presence of Porphyromonas gingivalis, Bacteroides forsythus, Actinobacillus actinomycetemcomitans, Prevotella intermedia and Prevotella nigrescens was evaluated by polymerase chain reaction technique on day 0 and 30 days after ligature placement. None of the above bacteria were detected on day 0. Thirty days after ligature placement, P. gingivalis was present in 95% and 85% and B. forsythus was present in 80% and 85% of the implants and teeth sites, respectively. Statistical analysis (one‐way RM‐ANOVA) showed a significant difference (P<0.01) between pre‐ and post‐induction measurements around teeth and implants. However, there was no significant difference (P=0.41) in the rate of attachment loss, between periodontitis and peri‐implantitis. It can be concluded that: (1) P. gingivalis and B. forsythus were strongly associated with induced peri‐implantitis and periodontitis, and (2) induced peri‐implantitis and periodontitis presented a similar rate of attachment loss.
Brånemark System® and ITI Dental Implant System® for treatment of mandibular edentulism
Authors: Moberg Lars‐Erik , Sagulin Gun‐Britt , Köndell Per‐Åke , Heimdahl Anders , Gynther Göran W. , Bolin Anders
Published: March 2003

Abstract: In a randomized prospective study, two implant systems were compared in forty consecutive patients treated for mandibular edentulism. The patients were randomly allotted for treatment by the Brånemark® two‐stage (submerged) system (BRS), or the ITI® one‐stage (non‐submerged) system. In all, 102 Brånemark selftapping implants and 106 ITI hollow screw implants were installed and all patients were treated with full bridges. Biological and prosthodontic parameters, complications, success rates, clinical efficacy, patient satisfaction and resource requirements were evaluated. No differences were found in plaque accumulation, bleeding or complications during the follow‐up period. The BRS group showed deeper periimplant sulcus, less attached mucosa, larger bridge‐mucosa distance and higher Periotest values. Prosthetic complications were not related to the configuration of the implant systems. After 3 years, the cumulative success rates were 97.9% and 96.8% for the Brånemark and ITI systems, respectively (difference not statistically significant). One implant in the BRS group had failed to osseointegrate at the time of abutment connection, and another was lost after 2 years due to progressive breakdown of bone. In the ITI group, three implants showed progressive bone loss after 1–3 years associated with periimplant infection. All 40 bridges were intact and remained stable throughout the study. There was general patient satisfaction, but about half the Brånemark patients reported difficulty in coping with the surgical procedures. Treatment time was similar for the two systems. It is concluded that both systems meet the current requirements for dental implant systems in the treatment of mandibular edentulism.
A retrospective analysis of factors associated with multiple implant failures in maxillae
Authors: Ekfeldt A. , Johansson L.‐Å. , Christiansson U. , Eriksson T. , Lindén U. , Lundqvist S. , Rundcrantz T. , Nilner K. , Billström C.
Published: March 2003

Abstract: This retrospective study was designed to verify the factors that influence implant failures. Six prosthodontic clinics in Sweden participated in the study, and together they included a total of 54 patients treated between January 1988 and December 1996. All patients were completely edentulous in the maxilla, and received either a fixed prosthesis or an overdenture supported by at least 4 implants (Brånemark System®). Half of the patients belonged to the study group, and an inclusion criterion for this group was that they had lost at least half of their implants. To reduce bias, the patients in the control group were matched to the study group, i.e. they were selected so that both groups were as identical as possible. The results of the study indicate that the control group had a better initial bone support than the study group. Furthermore, the patients in the study group suffered from circumstances that could induce implant failure, such as bruxism, personal grief, depression, as well as addictions to cigarettes, alcohol and/or narcotics. On the study form the clinicians were asked to give their own opinion of the reason for implant failure. The answers given could easily be grouped into 5 different topics, and this experience can be useful to improve patient selection. This study suggests that there are certain factors of importance to consider to prevent a cluster phenomenon of implant failures i.e. lack of bone support, heavy smoking habits and bruxism.
Plaque formation on surface modified dental implants
Authors: Größner‐Schreiber Birte , Griepentrog Michael , Haustein Ingrun , Müller Wolf‐Dieter , Briedigkeit Helga , Göbel Ulf Berthold , Lange Klaus‐Peter
Published: March 2003

Abstract: Bacterial adhesion on titanium implant surfaces has a strong influence on healing and long‐term outcome of dental implants. Parameters like surface roughness and chemical composition of the implant surface were found to have a significant impact on plaque formation. The purpose of this study was to evaluate the influence of two physical hard coatings on bacterial adhesion in comparison with control surfaces of equivalent roughness. Two members of the oral microflora, Streptococcus mutans and Streptococcus sanguis were used. Commercially pure titanium discs were modified using four different surface treatments: physical vapour deposition (PVD) with either titanium nitride (TiN) or zirconium nitride (ZrN), thermal oxidation and structuring with laser radiation. Polished titanium surfaces were used as controls. Surface topography was examined by SEM and estimation of surface roughness was done using a contact stylus profilometer. Contact angle measurements were carried out to calculate surface energy. Titanium discs were incubated in the respective bacterial cell suspension for one hour and single colonies formed by adhering bacteria were counted by fluorescence microscopy. Contact angle measurements showed no significant differences between the surface modifications. The surface roughness (Ra) of all surfaces examined was between 0.14 and 1.00 μm. A significant reduction of the number of adherent bacteria was observed on inherently stable titanium hard materials such as TiN and ZrN and thermically oxidated titanium surfaces compared to polished titanium. In conclusion, physical modification of titanium implant surfaces such as coating with TiN or ZrN may reduce bacterial adherence and hence improve clinical results.