Biomedical subjects

J Blomlöf

Publications and source records attributed to J Blomlöf.

6 recordsLinked to original sources

PubMed1996

Root cementum appearance in healthy monkeys and periodontitis-prone patients after different etching modalities.

The purpose of the present study was to compare cementum surfaces after etching at neutral or low pH in both healthy monkey teeth and periodontitis-affected human teeth. 16 monkey teeth and 16 human periodontitis-affected teeth were used. Etching with phosphoric and citric acids as well as EDTA was performed on the following surfaces: healthy monkey cementum, human cementum surfaces coronal and apical to the level of periodontal breakdown as well as exposed human dentin surfaces. Results indicate a profoundly higher capacity of EDTA to selectively expose collagen fibers in both healthy cementum surfaces and periodontitis-affected dentin surfaces compared to agents operating at low pH which seemed to erode the surfaces to varying degrees. Variable results were seen on cementum surfaces which had been exposed to the environment of the periodontal pocket or the oral cavity. In view of this, it would seem preferable to mechanically remove the superficial layer of "diseased" cementum prior to the etching procedure. In conventional periodontal surgery, etching may be of limited value. However, in regenerative procedures, exposure of an intact collagenous matrix provides a matrix for retention of implants of biologically active substances such as growth factors, in addition to serving as a biocompatible surface for periodontal ligament cell colonization.

Acid Etching, Dental↗

PubMed1996

Root surface etching at neutral pH promotes periodontal healing.

The purpose of the present investigation was to examine whether an etching agent operating at neutral pH (EDTA) can enhance healing compared to a low pH etching agent (citric acid) in an animal model. Maxillary molars and premolars, in total 32 teeth, in 4 monkeys were divided between test (EDTA or citric acid treatment) and matched control groups. Periodontal surgery on both palatal and buccal roots using the dehiscence model was performed with or without root surface etching. Healing results were evaluated histomorphometrically after 8 weeks. The statistically significant differences between EDTA treated surfaces (n=15) and control surfaces (n=11) were approximately 10% less failure (gingival recession and periodontal pocket), 10 to 15% more total histological attachment (long epithelial junction, connective tissue and reparative cementum), approximately 20% less long epithelial junction and approximately 20% more connective tissue in roots etched with EDTA. The statistically significant differences between citric-acid-treated surfaces (n=14) and control surfaces (n=11) were approximately 10% more connective tissue and 15% less long epithelial junction in the citric acid etched roots. Thus, etching with EDTA appeared to improve healing, avoiding the superficial necrotizing effect on exposed periodontal tissues by citric acid documented in previous studies. Although etching at present is not routinely applied in conventional periodontal therapy, future potential applications of etching at neutral pH may include exposure of the collagenous matrix of dentin for retention of biologically active substances, such as growth factors. Such treatment may be argued to produce a biocompatible surface more conducive to periodontal membrane cell colonization after removal of root-surface- associated smear without compromising the vitality of the surrounding periodontium.

Acid Etching, Dental↗

PubMed1995

Long-time etching at low pH jeopardizes periodontal healing.

The purpose of the present investigation was to examine whether the immediate necrotizing effects of low pH etching agents also impair periodontal healing in the long-term perspective. It was concluded that long-time etching (3 min) at low pH of root surfaces surrounded by vital periodontal issues resulted in impaired periodontal healing. In contrast, short-time etching appeared to promote connective tissue formation by preventing epithelialization of the periodontal wound despite its low pH. However, clinical inferences should be drawn with caution from the present results, since healing results recorded at 8 weeks may not prove to be stable, especially for those cases sensitive to the immediate influence of marginal infection such as connective tissue attachments and epithelial junctions, unless optimal oral hygiene is maintained. Furthermore, the choice of acid may be of importance.

Acid Etching, Dental↗

PubMed1995

Root surface texture and early cell and tissue colonization after different etching modalities.

The purpose of the present study was to compare the texture of dentin surfaces after etching with citric and phosphoric acids as well as EDTA with respect to mode of application and exposure time, and to assess possible effects on early cell and tissue colonization. It was concluded that EDTA operating at neutral pH was able to selectively remove mineral from a dentin surface, exposing a collagenous matrix. This was in contrast to etching with citric and phosphoric acids, both of which operate at a low pH. They both appeared to remove not only the mineral component but also the collagenous matrix. EDTA-treated dentin surfaces, compared to surfaces etched at low pH, appeared to be more inviting for cellular colonization and subsequent connective tissue formation. The reason for this may have been twofold: Dentin surfaces etched with an etching agent operating at neutral pH, as indicated above, retain more exposed collagen fibers than dentin surfaces etched at low pH. Furthermore, it can not be excluded that a low pH etching agent necrotized an area of the periodontal ligament in the immediate vicinity of the denuded dentin surfaces.

Acid Etching, Dental↗

PubMed1995

Periodontal tissue-vitality after different etching modalities.

The purpose of the present study was to investigate possible immediate necrotizing effects on periodontal tissues of etching agents operating either at low or neutral pH. Phosphoric and citric acids, both of which operate at low pH, exerted immediate (within 20 s) necrotizing effects on both mucosal flaps and periodontal tissues. The penetration depth increased with time up to 1/4 of the circumference of the root after 3 min. This was in sharp contrast to EDTA which operates at neutral pH. EDTA failed to induce any detectable necrosis during the experimental periods. Whether or not the immediate necrotizing effects of low pH etching agents also impair periodontal healing in the long-term perspective, needs to be evaluated with controlled experimental studies in vivo as well as clinically in order to determine whether etching at neutral pH is preferable.

Acid Etching, Dental↗

PubMed1994

Root surface texture after different scaling modalities.

Root surface texture after scaling with hand instruments, ultrasonic scalers (Amdent 830 and Cavi-Med 2000), and a sonic scaler (Titan-S) was assessed in vitro. The experimental material consisted of 48 extracted human teeth divided into six groups. Root surface texture was assessed with scanning electron microscopy (SEM). Hand and sonic instrumentation produced large grooves and removed cementum evident at a magnification of x 70, while the root surface alterations after ultrasonic instrumentation were not detectable below a magnification of x 500. The working principle of each scaling instrument in relation to its effect on the root surface was discussed.

Dental Cementum↗