Biomedical subjects

A Cederlund

Publications and source records attributed to A Cederlund.

5 recordsLinked to original sources

PubMed2001

A clinical histologic study of bovine hydroxyapatite in combination with autogenous bone and fibrin glue for maxillary sinus floor augmentation. Results after 6 to 8 months of healing.

Biopsies were taken from 16 out of 20 consecutive referral patients 6 to 8 months after maxillary sinus floor augmentation with a mixture of bovine hydroxyapatite (BH), autogenous bone particles and fibrin glue. Four days prior to biopsy retrieval the patients were given a single dose of tetracycline to label bone forming sites. Fluorescence microscopy of 100 microm thick sections revealed active bone formation in conjunction with the BH particles in 14 of 15 specimens analysed. Light microscopy and morphometry of ground sections from 16 patients showed various amounts of mineralised bone tissue in all except one specimen. In the latter case, the BH particles were encapsulated by a dense fibrous connective tissue. Sections from the augmented areas were occupied by non-mineralized tissue (54.1+12.6%), lamellar bone (21.2+24.5%), BH particles (14.5+10.3%) and woven bone (10.2+13.4%). The non-mineralized tissue seen in bone forming areas consisted of a loose connective tissue, rich of vessels and cells, and in the periphery of a more dense fibrous connective tissue. Woven bone with large and scattered osteocyte lacunae was bridging between the BH particles and the lamellar trabecular bone. There were no signs of resorption of the BH particles. The lamellar bone appeared to have originated from the recipient site and was seldom in contact with the BH particles. It is concluded that the tested implant material has bone conducting properties. The bone associated with the BH particles after 6 to 8 months of healing was mainly woven.

Aged↗

PubMed2001

Shear strength after ethylenediaminetetraacetic acid conditioning of dentin.

On the basis of previous studies, it was hypothesized that a chelating agent such as ethylenediamine-tetraacetic acid (EDTA) in a saturated aqueous solution (24%) can function as a dentin conditioning agent with exposure times comparable to that of phosphoric acid without compromising shear bond strength. Thirty caries-free human third molars, divided equally between two groups, were used. In group one, four experimental surfaces were prepared on each tooth, and cylindrical copper matrixes with a diameter of 5 mm were attached to the prepared surfaces. The experimental surfaces were then treated with a 24% EDTA gel for 30, 60, 120, or 240 sec, respectively. Dentin was bonded with All Bond 2, after which a flowable composite was added and light-cured. In group two, which served as control, two surfaces were prepared on each tooth. One surface was left unetched, whereas the other side was treated with 24% EDTA-gel for 30 sec. A shear bond strength test was performed at a crosshead speed of 1 mm/min until the composite debonded. There was no statistically significant difference (P< 0.89) between results of the shear bond strength test for the different EDTA conditioning times. The control group showed a significant difference in shear bond strength between untreated surfaces and surfaces conditioned for 30 sec with EDTA. Thus, the results indicate that the duration of EDTA gel conditioning of dentin surfaces need not exceed that of phosphoric acid in clinical practice to obtain an acceptable level of bond strength.

Acid Etching, Dental↗

PubMed2001

Acid conditioning combined with single-component and two-component dentin bonding agents.

OBJECTIVE: The purpose of the present study was to compare ethylenediaminetetraacetic acid conditioning and phosphoric acid conditioning of dentin in combination with two principally different commercial dentin bonding systems. METHOD AND MATERIALS: Twenty-one extracted human third molars were used. All teeth were caries free, and no teeth were root filled. In total, 29 pairs of dentin surfaces were obtained from 21 teeth. One dentin surface in each pair was etched with a 32% phosphoric acid gel for 15 seconds, and the opposite surface was etched with a 24% ethylenediaminetetraacetic acid gel for 3 minutes. One experimental group of 15 dentin surface pairs was subsequently bonded with All-Bond 2, a two-component system, and the other group of 14 pairs was bonded with Prime & Bond NT, a one-bottle adhesive. A flowable resin composite was inserted in the experimental cavity and light cured. Shear bond strength testing was performed according to the protocol of the International Organization for Standardization. RESULTS: The combination of conditioning with ethylenediaminetetraacetic acid and bonding with All-Bond 2 was significantly better than all other combinations, providing a shear bond strength that was 61% to 123% greater. CONCLUSION: Use of ethylenediaminetetraacetic acid in combination with All-Bond 2 resulted in a significantly greater bond strength to dentin than did conventional acid etching.

Acid Etching, Dental↗

PubMed1999

Effect of a chemo-mechanical caries removal system (Carisolv) on dentin topography of non-carious dentin.

The purpose of the present study was to examine the morphology of healthy dentin surfaces after treatment with Carisolv followed by conditioning with phosphoric acid and EDTA, since surface morphology may be of interest for dentin bonding. Another purpose was to evaluate the effect of treatment with Carisolv on healthy non-carious dentin surfaces with exposed collagen fibers. Scanning electron microscopy was utilized to carry out a detailed morphological examination of the dentin surfaces with regard to presence or absence of both smear layer and collagen fibers. Twelve premolars extracted for orthodontic reasons from young adults were used. The two etchants appeared to have produced two distinctly different surfaces. Etching with phosphoric acid following Carisolv treatment resulted in a porous dentin surface, while EDTA etching without prior Carisolv treatment appeared to have uncovered an intact collagen network. In contrast, the surfaces treated with Carisolv prior to EDTA etching displayed smooth intertubular surfaces with only occasional fibers. Apparently, the ability of EDTA to expose collagen in the dentin surface is counteracted or inhibited by the Carisolv treatment. Furthermore, it cannot be excluded that the Carisolv treatment in itself may have dissolved collagen fibers. Since most bonding systems claim bonding to the collagenous component of dentin, the question arises which of the etched surfaces is preferable and to what degree the collagenous component contributes to bonding strength. Further studies are thus needed to evaluate the micromechanical retention of a restoration to the different surfaces described in the present study.

Acid Etching, Dental↗

PubMed1999

Efficacy of Carisolv-assisted caries excavation.

As a possible alternative to conventional techniques for excavating caries chemomechanical methods have been developed. Caridex has so far been the dominating product. However, a new system, Carisolv, was recently introduced. The purpose of the present study was to evaluate the caries-dissolving efficacy of Carisolv in vitro. After excavation with Carisolv all dentin surfaces were caries free. However, 6 of the 10 cavities showed residual caries in the dentinoenamel junction. The dentin and enamel surfaces were covered by smear and debris. Since there may be a risk of leaving caries in the dentinoenamel junction proper case selection appears to be of importance to ensure a successful result.

Adult↗