Biomedical subjects

C De Putter

Publications and source records attributed to C De Putter.

8 recordsLinked to original sources

PubMed1999

A clinical evaluation of 76 implant-supported superstructures in the composite grafted maxilla.

The aim of the study was to evaluate the material behaviour and nature of implant-supported superstructures in function. A total of 37 overdentures, 26 fixed partial and 13 fixed full dentures with a mean lifetime of 40 months were clinically evaluated in relation to damage, occlusion and articulation, parafunction, retentive devices, hygiene and speech problems. In general 70% of all superstructures were damaged. Fixed partial dentures were significantly less damaged than overdentures and fixed full dentures (P<0.001). A significant high percentage of newly gained parafunction was found (P<0.05).

Adult↗

PubMed1997

Flexible (Polyactive) versus rigid (hydroxyapatite) dental implants.

In a beagle dog study, the peri-implant bone changes around flexible (Polyactive) and rigid hydroxyapatite (HA) implants were investigated radiographically by quantitative digital subtraction analysis and by assessment of marginal bone height, with the aid of a computerized method. A loss of approximately 1 mm of marginal bone height was observed for both the dense Polyactive and the HA implants, after 6 months of loading. This value appeared to be stable from 12 weeks of loading onward. Along the total length of the implant during the first 6 weeks of loading, both the flexible (dense Polyactive) and the rigid (HA) implants showed a decrease in density. However, after this 6-week period, the bone density around the implants increased, and after 18 weeks the original bone density was reached. The flexible Polyactive implants provoked less decrease in density than the rigid HA implants, although not to a statistically significant level. This finding sustains the hypothesis that flexible implant materials may transfer stresses to the surrounding bone more favorably.

Alveolar Bone Loss↗

PubMed1996

Front tooth replacement with Tübingen (Frialit) implants: a radiographical evaluation.

A total of 214 radiographs of 76 Tübingen implants placed in the anterior region of the maxillae of 56 patients were evaluated by two observers. The first radiographs were taken after implant placement (n = 76). The second set of radiographs were taken during months 13-23 (n = 53), the third during the months 24-35 (n = 28), the fourth during months 36-47 (n = 15), the fifth during months 48-59 (n = 18) and the sixth during months 60-72 (n = 20). Only four radiographs were available after longer periods, namely the eight and the ten year of function. The two observers together classified the marginal bone height (mesial and distal) as 0 (no resorption) or 1-5 in steps of 2.5 mm resorption. A score of 1 represents marginal bone resorption less than 2.5 mm, 2 from 2.5 mm to 5 mm, 3 from 5 to 7.5 mm, 4 from 7.5 to 10 mm and 5 more than 10 mm loss of marginal bone height. Thirty-six implants scored marginal bone height of 0 or 1. Twenty-two implants scored not higher than 2. Eight implants scored bone loss up to 3, four up to 4 and one up to 5. Five implants were lost.

Aluminum Oxide↗

PubMed1995

Delayed implants in the anterior maxilla with the IMZ-implant system.

One hundred and seventy-three IMZ two-stage implants have been clinically and radiologically evaluated for a 5 year period. The implants were placed in the anterior region of the maxillae of 81 patients to replace lost incisors, cuspids and bicuspids. The implants were placed 3 months or later after loss of natural anterior teeth when the resorption was already in an advanced stage. The implants used in this study consisted of titanium coated with hydroxylapatite. The prosthetic restorations placed on the implants consisted of fixed or removable partial dentures and single crowns. The cumulative percentage for implant survival after 3 years, with a mean follow-up of 33.5 (s.d. 17.8) months was 96.1%. Although the prosthetic restorations aesthetically often were a compromise they did prove highly satisfactory to both patients and dentists.

Adolescent↗

PubMed1994

Front tooth replacement with Tübingen (Frialit) implants.

127 Tübingen (Frialit) implants have been clinically evaluated for a 10 year period. The implants were placed in the anterior region of the maxillae of 101 patients to replace lost incisors, cuspids and premolars. Seventy-seven implants were placed within 3 months after loss of a natural anterior tooth, resulting in the preservation of the volume of the alveolar ridge and the contour of the surrounding soft tissues. This preservation of the volume of the alveolar ridge was due to the fact that the Tübingen implants have conical shapes and sizes, equal to those of the roots of natural teeth. The dentine-like colour and the biological properties of the bio-inert Al2O3 implant-material, in most of the cases was an advantage to the aesthetics of the prosthetic restorations and to the condition of the soft tissues in the permucosal area. The Tübingen implant is placed with a one-phase technique implying special care for the temporary restorations to avoid premature loading. Also prevention of overloading the ceramic material by the fixed restoration needs special attention in the construction of posts, cores and crowns. The overall survival-rate in this study with a mean follow-up of 4.5 years was 87%. Patient and dentist satisfaction was high.

Adolescent↗

PubMed1993

Structure of the bone interface to dental implants in vivo.

Dental implant materials can develop different kinds of interfaces when used for bone or tooth substitution. This paper describes the tissues and the tissue reactions of the interface created in the implantation bed between bone tissue and implants made of dense sintered hydroxylapatite. Healing was clinically and histologically evaluated during a six-month to five-year period. The light microscopic results show extensive bone apposition on the osseous sides of loaded implant cylinders and also on subperiosteally placed granules of dense hydroxylapatite. The presence of the loaded implant did not disturb the normal bone physiology. Bone turnover also included the bone tissue toward the implant surface. At the ultrastructural level, an amorphous collagen-free zone of about 200 nm was frequently observed which was separated from the surrounding mineralized extracellular matrix by a thin, electron-dense layer of about 20-100 A. Contact microradiographs showed an intimate bond to bone. The bone growth extending up the implant cylinder was always accompanied with an embedding of collagen fibers and the presence of a well-developed and complete new gingival attachment apparatus. This was confirmed by scanning electron microscopy. However, any inflammatory reactions in the transmucosal area were accompanied with concomitant bone resorption and loss of bone support.

Alveolar Process↗

PubMed1990

Histological and ultrastructural appearance of the hydroxyapatite-bone interface.

This article describes the histological and ultrastructural appearance of the interface created in the implantation bed, between bone tissue and implants made of dense sintered hydroxyapatite (HA). Biopsies from dog subjects included: a) loaded permucosal dental implants for tooth substitution, b) subperiosteally placed implants for alveolar bone correction, c) endosseously placed dental root implants to retain ridge form following extraction. The light and electron microscopical results show extensive bone apposition on the osseous sides of the implant surfaces. There is an intimate, direct bone contact without any visible interruption. The bone is of normal lamellar type and continuously connected with the trabecular bone. Bone has grown into the finest surface irregularities of the implant. Collagen fibers of the calcified bone matrix are observed within a distance less than 500 A from the implant surface. The thin (20-100 A) electron dense layer at the bone-implant interface resembled the lamina limitans of organic bone matrix, also seen at the inner walls of the osteocytes lacunes. Deposition of bone gives rise to a biologically stable bone-implant interface, without disturbance of the physiological bone turnover. This is seen as very favorable for desired long term fixation of implant to bone.

Animals↗

PubMed1989

A clinical, radiographic, and histological evaluation of permucosal dental implants of dense hydroxylapatite in dogs.

A clinical, histological, and radiographic examination was performed on 77 permucosal dental implants, made of dense sintered hydroxylapatite: 34 solid cylinders and 43 hollow cylinders. The hollow cylinders were pre-compressed between two titanium caps. The implants were placed in partly edentulous mandibles of dogs, and were physiologically loaded. Healing was clinically and radiographically evaluated during a six-month to five-year period. At various times, implants with their surrounding tissues were removed and prepared for light and electron microscopy. All implants showed a good initial fit and were maintained in place without undercut or mechanical stabilization. After 18 months, 76% of the solid cylinders had fractured at the implant/bone junction due to fatigue. However, the submerged portions of the solid cylinders were preserved without clinical problems, and became entirely embedded in bone. The pre-stressed implants did not fracture, and 91% were functioning 24 months after placement. The average scores of pocket depths and gingival bleeding showed no significant differences between implants and surrounding natural teeth. Bone deposition occurred on the entire surface of the implant below the crest of the alveolar bone, and intimate bone contact was confirmed by electron microscopy. It was also observed that a layer of bone tissue was deposited on the implant surface in the permucosal area just above the alveolar bone level. Embedding of gingival fibers in this layer resulted in gingival attachment to the implant, comparable with that of natural teeth.

Alveolar Process↗