Biomedical subjects

L Blomlöf

Publications and source records attributed to L Blomlöf.

At least 19 recordsLinked to original sources

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↗

PubMed1994

Extraoral root lengthening with titanium screws.

The aim of the present study was to experimentally evaluate marginal and periapical healing in extracted and subsequently replanted teeth following extraoral cementing of apically exposed titanium root screws in the root canal. In 5 out of 6 replanted teeth, the periodontal tissues had healed with a normal periodontal membrane or healed surface resorptions indicating that only minor trauma had been inflicted during the extraoral procedure. In 3 out of 6 teeth, total or partial osseointegration of the titanium screws was seen, while a connective tissue capsule had formed around the remaining 3 screws. It was concluded that both of the healing results described in the present study, osseointegration and connective capsule formation, may be regarded as acceptable as long as inflammation is prevented, although it remains to be shown which one represents the end-point.

Alveolar Process↗

PubMed1994

Proximal restorations and periodontal status.

The purpose of the present investigation was to evaluate the influence of overhanging marginal restorations on periodontal status and whether any such influence is modified by the patient's oral hygiene level and degree of radiographic attachment loss. The investigation was conducted as a retrospective study on a consecutive referral population. Periodontal pockets at proximal sites with marginal overhangs were significantly deeper (0.42 mm) compared to sites with metal restorations without overhangs. This difference was larger (0.62 mm) for sites with radiographic attachment loss < or = 6 mm, while no significant difference was found for sites with radiographic attachment loss > 6 mm. In patients with a mean radiographic attachment loss < or = 5 mm, an overhanging restoration margin was associated with a significantly increased loss of radiographic attachment (0.66 mm). It was concluded that the influence of a marginal overhang on pocket depth and radiographic attachment decreases with increasing loss of periodontal attachment in periodontitis-prone patients. The effect on pocket depth of a marginal overhang may act synergistically, potentiating the effect of poor oral hygiene.

Adult↗

PubMed1994

Differential periodontal temperature measurements in the assessment of periodontal disease activity: an experimental and clinical study.

The difference in surface temperatures between the bottom of periodontal pockets and the attached gingiva adjacent to the openings of the pockets were determined both in monkeys with experimental marginal periodontitis, and clinically in patients with marginal periodontitis. For this purpose a custom-made, temperature-measuring device was developed which enabled immediate recording of temperature differences as well as periodontal pocket depths, bleeding, and attachment levels. The measurements were performed periodically. The differential temperature measurements were correlated to change in periodontal attachment over time. It was shown that differential periodontal temperatures are well correlated to change in periodontal attachment over time. It was furthermore concluded that differential periodontal temperature measurements have the potential of serving as a predictor of activity of marginal periodontitis. However, more extensive data are required to assess the sensitivity and specificity of the method.

Animals↗

PubMed1994

Quality of periodontal healing. I: Review of the literature.

This summary focuses on quality of healing following periodontal surgical and non surgical procedures. It is based on a survey of the literature on clinical, radiographic and histological assessment as well as on 3 recent studies on the quality of periodontal healing published in this Journal.

Alkaline Phosphatase↗

PubMed1994

Quality of periodontal healing. II: Dynamics of reparative cementum formation.

The purpose of the present study was to follow the formation of mineralised tissue (reparative cementum) on instrumented root surfaces. Twenty-four permanent maxillary and mandibular laterals from six, 3-4-year-old monkeys (macaca fascicularis) were used in the experiment. The incisors were gently extracted and the periodontal membrane (PDM) and cementum on the mesial surface of the roots removed to a distance of 1-2 mm from both the cemento-enamel junctions and the apices of the roots. The teeth were subsequently replanted. Ankylosis was seen both after 3 and 5 wks, although to a lesser degree at 5 wks to be virtually absent at 10 wks. It appeared that the resorptive activity predominant at 5 wks had removed the ankylotic fusion. After 10 weeks, a remaining layer of mineralised tissue, commonly referred to as reparative cementum was seen to cover the denuded dentine surfaces in the present study. It appeared not to be firmly attached to the root surface and did not show a normal cementum-morphology in polarised light. It had a multi-layered appearance resembling alveolar bone tissue and the connective tissue fibres adjacent to the reparative mineralised tissue-layer were not functionally oriented but rather parallel to the root surface. It was concluded that the formation of this mineralised tissue (rearative cementum) was the result of a transient ankylosis.

Alveolar Bone Loss↗

PubMed1994

Quality of periodontal healing. III: Periodontal width following long epithelial junction or reparative cementum formation.

The purpose of the present study was to compare the width of the periodontal space following two different marginal periodontal healing reactions (long epithelial junction and connective tissue healing involving formation of reparative cementum) with the width of normal periodontium, either intact or following reattachment. Twelve permanent lateral incisors in monkeys from a previous experimental study on periodontal wound healing on denuded surfaces were selected based on strict healing criteria. The periodontal width was measured histomorphometrically and compared to the periodontal width on the contra lateral side of the same root where reattachment had taken place and with the width of normal periodontal space of neighbouring untreated teeth. The mean periodontal width for both after formation of a long junctional epithelium and reparative cementum were significantly larger than the control width, approximately 290%. This may be taken as evidence of an impaired functional adaptation of the reparative tissue compared to a reestablished or normal periodontal membrane.

Animals↗

PubMed1994

Quality of periodontal healing. IV: Enzyme histochemical evidence for an osteoblast origin of reparative cementum.

The aim of the present study was to map the distribution of healing gingival and periodontal connective tissue well as osteoblastic activity in marginal periodontal wound healing using activity of alkaline phosphatases as markers. Activity of non-specific alkaline phosphatase (NSAP) was abundant in periodontal but not in gingival connective tissue. Activity of vanadate-resistant alkaline phosphatase (VRAP) had a preferential localisation to periosteal and endosteal bone surfaces but was not detectable in cementoblasts along root surfaces. However, following spontaneous marginal healing of exposed dentine surfaces, activity of VRAP was also found on healing dentine surfaces. It was concluded that osteoblasts rather than cementoblasts form reparative cementum on exposed dentine surfaces during marginal periodontal healing.

Alkaline Phosphatase↗

PubMed1993

Relationship between periapical and periodontal status. A clinical retrospective study.

The purpose of the present investigation was to explore possible relationships between clinical periodontal status in periodontally involved teeth with and without endodontic infection. The investigation was conducted as a retrospective study on a consecutive referral population. The periapical conditions in endodontically-involved single-rooted teeth from a selected patient sample were evaluated and correlated to their periodontal status. There was a significant correlation between periapical pathology and vertical bony destructions. An intra-individual comparison between pocket depth in teeth with and without periapical pathology showed that periapical pathology was significantly correlated to an increased pocket depth in the absence of a vertical bony destruction. It was concluded that an endodontic infection, evident as a periapical radiolucency, promotes periodontal pocket-formation on an instrumented marginal root surface and, consequently, should be regarded as a risk factor in periodontitis progression and be given appropriate consideration in periodontal treatment planning.

Adult↗

PubMed1993

Periodontal healing in teeth with periapical lesions. A clinical retrospective study.

The purpose of the present investigation was to compare clinical periodontal healing in periodontally involved teeth with and without pulpal pathosis. The investigation was conducted as a retrospective study on a consecutive referral population. The periapical conditions in endodontically involved single-rooted teeth from a selected patient sample were evaluated and correlated with their periodontal healing pattern. Multiple regression analysis of the registered variables showed that initial mean pocket depth and time elapsed after treatment significantly influenced change in pocket-depth. Non-surgical treatment of periodontal pockets exceeding 2.5 mm in teeth with horizontal marginal defects, over the observation period, showed significantly reduced mean pocket depth reduction in teeth with periapical pathology compared to teeth without periapical pathology. It was, furthermore, evident that proximal restorations, abutments for fixed bridges and root fillings with and without dowels did not significantly influence pocket depth reduction in the present material. It was concluded, based on the present results, that a root-canal infection, evident as a periapical radiolucency, if left untreated may in the long term perspective result in retarded or impaired periodontal healing following periodontal therapy and, consequently, should be given appropriate consideration when coordinating endodontic therapy and periodontal treatment.

Adult↗

PubMed1993

Successive removal of periodontal tissues. Marginal healing without plaque control.

The aim of the present study was to compare periodontal healing after successive removal of periodontal tissue components, from the alveolar bone to the dentin surface. The prevailing tissue reaction when adhering PDM was left on the exposed roots was that most of the bone tissue that had been removed from the buccal surfaces had regenerated and the integrity of the PDM between the new alveolar bone and cementum surface had been reestablished. On exposed etched cementum surfaces, 2 prevailing healing results were recorded. In half the number of the roots, the root surfaces were covered by connective tissue with fibers running parallel to the root surfaces in a capsule-like arrangement. The other prevailing reaction was a thin epithelial cell-lining running parallel to the root surfaces in close contact or partly penetrating the adjacent connective tissue. On exposed denuded dentin surfaces, gingival retraction was a constant finding, associated with an epithelial cell-lining of varying thickness sometimes with rete pegs and cyst-like formations. Gingival retraction was also a constant finding on etched dentin surfaces. This was associated with pathological pockets outlined by epithelial cell-layers of varying thicknesses. The significance of these findings were discussed with special emphasis on dynamics of recurrent periodontitis.

Acid Etching, Dental↗

PubMed1993

Development of periapical lesions.

The purpose of the present study was to follow the development of periapical lesions both radiographically and histologically in infected teeth with open and sealed root canals. The mandibular premolars from five adult monkeys were used in the experiment. Sealed infected teeth developed radiographic signs of periapical pathosis significantly earlier than unsealed teeth. Although, histological signs of pathology could be seen periapically at earlier observation periods, sealed teeth consistently developed these changes earlier than unsealed teeth. Furthermore, the histological periapical pathology differed somewhat between the two groups in that unsealed teeth showed a multi-focal diffuse pattern of spreading.

Animals↗

PubMed1993

Tissue formation on cementum surfaces in vivo.

The purpose of the present investigation was to study cell colonization of and tissue formation on denuded (anorganic) cementum surfaces as well as denuded demineralized cementum surfaces. The most conspicuous finding was the distinctly different pattern of cell colonization and subsequent tissue formation on etched and non-etched denuded cementum surfaces. Non-etched cementum surfaces displayed a limited number of resorbing cells and resorption lacunae, while etched cementum surfaces displayed an abundance of fibroblast-like cells in varying stages of activity in a meshwork of fibres, probably collagenous. These fibres were organized in a layer parallel to the root surface. This appearance of a fibrous capsule-like structure has previously been associated with periodontal healing with a non-functional repair-tissue. It may be concluded, based on the present results that, a cementum surface in which collagen fibers have been exposed presents a suitable surface for colonization by mesenchymal cells. However, if collagen fibers are not exposed in the cementum surface leaving mineralized surface, mesenchymal cells appear not to be able to attach.

Acid Etching, Dental↗

PubMed1992

Endodontic infection and calcium hydroxide-treatment. Effects on periodontal healing in mature and immature replanted monkey teeth.

Large experimental defects with marginal communication, and small isolated experimental defects were created on the root surfaces of extracted monkey lateral incisors with either open or closed apices. The pulp tissue was either infected or removed, and calcium hydroxide placed in the root canal. The teeth were then replanted and the healing pattern evaluated histomorphometrically after 20 weeks. From the results, it was concluded that (1) an intrapulpal infection promotes marginal epithelial down-growth on a denuded dentin surface irrespective of tooth developmental stage, and that (2) the periodontal healing potential after calcium hydroxide-treatment appears to be higher in teeth with open apices compared with teeth with closed apices, where ankylosis was promoted as opposed to teeth with open apices where significantly more reparative cementum was found.

Animals↗

PubMed1992

Mineralized tissue-formation in periodontal wound healing.

The purpose of the present study was to examine and compare the different mineralized tissues that are found on and around the dental root following treatment of different periodontal pathosis. The material has been compiled from previously published experimental studies on periodontal therapies and trauma treatments. 4 distinctly different appearances of the mineralized tissue layers on the marginal dentin surfaces were described; new cementum, non-attached bone-like tissue, partly attached bone-like tissue and ankylosis preceded by root resorption. It was concluded that, healing in the periodontal/root interface following periodontal therapy may yield different mineralized tissues, depending on a number of host-specific and external factors. The temporal pattern of such healing processes is schematically represented.

Alveolar Bone Loss↗

PubMed1991

Effect of immediate calcium hydroxide treatment and permanent root-filling on periodontal healing in contaminated replanted teeth.

The effect of immediate permanent root-filling and immediate intracanal calcium hydroxide treatment on experimentally contaminated and necrotized periodontal membranes (PDM) in avulsed and subsequently replanted monkey teeth was studied. Almost the entire root surface in the non-endodontically treated control teeth were covered with inflammatory resorption. A significant shift towards ankylosis not associated with root resorption (greater than 80% of the total root surface area) was noted following calcium hydroxide treatment. About two thirds of the root surfaces from the teeth with permanent root fillings showed surface resorptions or ankylosis preceded by root resorption. The root surface area which would have been covered by inflammatory resorption, unless endodontic treatment had been implemented, were instead predominantly covered by either surface resorption (permanent root filling) or ankylosis (calcium hydroxide treatment). Ankylosis compared with surface resorption may in the long term lead to progressive loss of root substance due to replacement resorption. It was concluded that calcium hydroxide may be an excellent initial intracanal treatment in teeth with healthy PDM, but care should be taken not to risk unnecessary development of ankylosis by prolonged treatment of teeth with compromised PDM.

Alveolar Process↗

PubMed1991

Effect of delayed calcium hydroxide treatment on periodontal healing in contaminated replanted teeth.

The effect of delayed intracanal calcium hydroxide treatment on experimentally induced extensive inflammatory root resorption in monkeys was studied. A significant shift from inflammatory resorption to ankylosis was noted following calcium hydroxide treatment. Furthermore, calcium hydroxide treatment appeared to change the pattern of ankylosis over time, although the total ankylotic area remained the same. Ankylosis preceded by root resorption (replacement resorption) increased, while ankylosis not associated with root resorption decreased. It was concluded that intracanal calcium hydroxide treatment of teeth with compromised PDM may cause unnecessary replacement resorption if left in the root canal for a long time or changed repeatedly.

Alveolar Process↗

PubMed1990

Cellular reactions in pulpal and periodontal tissues after periodontal wound debridement.

Periodontal wounds in monkeys were prepared with a bur followed by the application of microbially contaminated cotton pellets. 3 weeks later, the wounds were debrided by scaling followed by etching with citric acid or by treatment with carbonate/peroxidate. The cellular reactions in the periodontal tissues and in the pulp 4, 11, 25, 39 and 53 days after treatment were followed with light microscopy. The marginal periodontium showed heavy inflammatory reactions immediately after treatment, regardless of the debridement procedure. 25 days after debridement, a long epithelial junction had been formed. The apical part of the epithelium deviated from the root surface into the connective tissue, delineating a heavily inflamed part of the connective tissue. After 39 to 53 days, most of the experimental wounds were covered by an epithelial lining. The pulpal reactions were generally limited to a production of irregular dentin on the pulpal wall facing the periodontal wound. It was concluded that the marginal healing pattern following various chemical treatments to the root surface followed, in all essential aspects, conventional treatment with scaling and root planing.

Animals↗