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Biomedical subjects

J Blomlöf

Publications and source records attributed to J Blomlöf.

13 recordsLinked to original sources

A clinical study of root surface conditioning with an EDTA gel. I. Nonsurgical periodontal treatment.

The present study was undertaken to investigate if subgingival administration of an EDTA gel has any adjunctive effect to subgingival and supragingival root debridement. The investigation was performed in one study center involving 6 clinical investigators and 91 patients. The patients were selected from 2 patient populations: 41 were included from a consecutive referral material on a voluntary basis, and 50 were included from a maintenance care material at the clinic. No significant differences were found between the EDTA-treated and control groups with respect to clinical attachment gain or probing pocket depth reduction. The referral patients showed a significant improvement of pocket depth and attachment gain compared to maintenance care patients at the clinic. In multiple regression analyses, it was found that patients with small attachment losses at baseline responded better to treatment than patients with severe periodontitis. Also, in multivariate analyses, referral patients responded better than maintenance patients when controlling for other predictors.

Adult↗

A clinical study of root surface conditioning with an EDTA gel. II. Surgical periodontal treatment.

The objective of the present trial was to assess the effect of an EDTA gel applied during surgical periodontal therapy on probing depth reduction and periodontal attachment gain, allowing for the influence on healing of smoking as well as postsurgical oral hygiene. For comparison, citric acid treatment and control surgery only were included. The investigation was performed in one study center involving one clinical investigator and 68 patients. The patients were selected from a consecutive referral material on a voluntary basis. No statistically significant differences between treatment groups concerning attachment gain or pocket depth reduction could be seen after 3 and 6 months. A subgroup of the sample--21 patients who scored zero on the bleeding index at 3 and 6 months postsurgery and did not smoke--had a borderline significantly higher attachment gain in response to experimental treatment as well as a significant pocket depth reduction 6 months postsurgery when controlling for age, gender, Plaque Index at baseline, and treatment in multiple regression analyses. However, this was true not only for EDTA treatment but for citric acid and control treatment as well.

Adult↗

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↗

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↗

Effect of different concentrations of EDTA on smear removal and collagen exposure in periodontitis-affected root surfaces.

The purpose of the present study was to explore the possibility of obtaining an acceptable smear-removing and collagen-exposing effect following EDTA etching with concentrations lower than supersaturation (24%). A flat dentin surface was created on human teeth extracted due to severe periodontitis. The teeth were etched with the following concentrations of EDTA for 2 min: 1.5% (group I), 5% (group II), 15% (group III) and 24% (group IV), and evaluated with scanning electron microscopy with respect to smear layer removal and exposure of root-associated collagen fibers. It was found that neither 1.5% nor 5% EDTA etching was sufficient to dissolve the smear layer to any higher degree. Etching with 15% EDTA dissolved the smear more effectively than the lower concentrations and collagen fibers were sparsely found. Following etching with 24% EDTA (group IV), significantly less smear was seen on the dentin surfaces than in any of the other groups and collagen fibers were seen covering the entire intertubular dentin surfaces. Based on these findings, the concentration of EDTA should be somewhere between 15 to 24% in order to obtain an acceptable smear removing and collagen-exposing effect within a clinically acceptable time period.

Acid Etching, Dental↗

Lingual deficits in BDNF and NT3 mutant mice leading to gustatory and somatosensory disturbances, respectively.

A combination of anatomical, histological and physiological data from wild-type and null-mutated mice have established crucial roles for BDNF and NT3 in gustatory and somatosensory innervation of the tongue, and indeed for proper development of the papillary surface of the tongue. BDNF is expressed in taste buds, NT3 in many surrounding epithelial structures. Absence of BDNF in mice leads to severely malformed taste bud-bearing papillae and severe reduction of taste buds, a loss of proper innervation of remaining taste buds and a loss of taste discrimination although not of the suckling reflex per se. In contrast, absence of NT3 leads to a massive loss of somatosensory innervation of lingual structures. These findings demonstrate distinct roles for BDNF and NT3 in the establishment of the complex innervation apparatus of the tongue with non-overlapping roles for the lingual gustatory and somatosensory systems. The distinction between different sensory modalities, being dependent on either BDNF or NT3 may also have clinical implications.

Animals↗

Ultrasonic subgingival root planing and EDTA etching in a one-step procedure.

The purpose of the present study was to investigate if ultrasonic debridement and EDTA etching could be combined in a ore-step procedure. Tap water was exchanged for a 24% EDTA solution as irrigation agent during root planing with a piezo scaler. 24 human teeth extracted due to severe periodontal disease were used and the results were evaluated with scanning electron microscopy. Results indicate that synergistic effects (smear removal and exposure of collagen fibers) were negligible with conventional application of the irrigation fluid to the working area of the scaling tip while a marked effect was evident when the EDTA solution was applied directly to the working area of the piezoelectric scaler through a customized tip.

Acid Etching, Dental↗

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↗

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↗

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↗

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↗

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↗

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↗