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At least 487 records · Page 27Linked to original sources
PubMed1997

Excisional wound healing following the use of IRM as a root-end filling material.

Intermediate Restorative Material (IRM) has been advocated as a root-end filling material based primarily on reports of clinical success and various leakage studies. The objectives of this study were to determine the excisional wound healing responses of the periradicular tissues to IRM root-end filling material and to compare this with the wound healing responses to amalgam and orthograde gutta-percha root-end filling materials. Mandibular premolars in dogs were obturated, root-ends resected, and the healing responses associated with root-end fillings of IRM, amalgam, and orthograde gutta-percha were evaluated microscopically and radiographically at postsurgical intervals of 10 and 45 days. The excisional wound healing responses associated with IRM root-end fillings were normal at both postsurgical intervals. There was no evidence of inhibition of dentoalveolar or osseous wound healing associated with IRM, amalgam, or orthograde gutta-percha. Statistical analysis showed no difference in wound healing between the 3 root-end filling materials.

Alveolar Process↗
PubMed1996

Wound healing after mucoperiosteal surgery in the cat.

The purpose of this study was to examine possible tissue-dependent differences in rate of healing after mucogingival flap surgery. After intrasulcular incision and a vertical-releasing incision distal to the maxillary and mandibular cuspids, buccal, full-thickness mucogingival flaps were raised in four quadrants of 10 adult cats. The triangular flaps were left open for 30 min and then repositioned and sutured. Tissue reactions were studied histologically after 1, 3, 7, 14, and 28 days of healing. Although new collagen occasionally was observed in the wound space in the free gingiva at 3 days, collagenous union between the cut dentogingival fibers and the flap seemed well established at 7 days. Flap reattachment to the denuded cortical bone was seen at 14 days in the region of the attached gingiva. In the region of the alveolar mucosa, however, residual coagulum and inflammatory reaction was present as late as at 28 days in several specimens. These observations indicate a marked difference in rate of healing among the different interfaces involved. These variations seem to be related to variations in size of the resulting wound space when a full-thickness mucoperiosteal flap is readapted over cervical root surfaces, alveolar bone crest, and denuded cortical bone, respectively.

Animals↗
PubMed1998

Use of a hydroxylapatite-based material and calcium sulfate as artificial floors to repair furcal perforations.

OBJECTIVE: The purpose of this study was to evaluate a hydroxylapatite-based material and calcium sulfate when each was used under a resin-modified glass ionomer cement to repair furcation perforations. STUDY DESIGN: Perforations of pulp chamber floors were made in 72 teeth of 9 dogs. Perforations were divided into 3 equal-sized groups and repaired with resin-modified glass ionomer either alone or over an artificial floor. The artificial floor was either a hydroxylapatite-based material or calcium sulfate. Three dogs were killed at each of 3 intervals (1, 3, and 6 months). The tissue response to the tested materials was evaluated clinically, radiographically, and histologically. RESULTS: The hydroxylapatite-based material showed the highest radiographic success; this was followed by calcium sulfate and glass ionomer. From histologic evaluation, the average success rate was found to be 67% for calcium sulfate, 62% for the hydroxylapatite-based material, and 59% for glass ionomer. However, there was no statistical significant difference with the resin-modified glass ionomer when it was used alone and when it was used over a barrier. There was also no significant difference between the hydroxylapatite-based material and the calcium sulfate when they were used as artificial floors. CONCLUSION: The use of an artificial floor may not be necessary when flowable resin-modified glass ionomer cements are used.

Animals↗
PubMed2003

Unusual in vivo extensive corrosion of a low-silver amalgam restoration involving galvanic coupling: a case report.

The basic mechanism of dental amalgam corrosion has been thoroughly studied during the last 50 years by various experimental techniques, most often carried out in vitro. Electrochemical methods were extensively employed, and it was recognized that a gradual dealloying of the more electroactive components, Zn, Sn, and to a lesser extent Cu, contributed to change the surface composition. It is also well known that, in all circumstances, galvanic coupling threatens the longevity of the restoration. Among the patients examined at the hospital attached to the Department of Dental Surgery of the Paris 5 University, the authors observed, in a few exceptional circumstances of defective restorations, a release of liquid metal droplets in the surrounding tissue. These particles were identified as elemental mercury. This unexpected phenomenon was the result of the use of a low-silver-content alloy, combined with an enhanced corrosion process due to galvanic coupling with a silver alloy crown and brass screw-posts. In the described clinical case, the tooth, which had to be extracted, was axially sliced for observation by scanning electron microscopy coupled with elemental analysis by X-ray fluorescence energy dispersive spectroscopy. The observations showed a dramatic corrosion of the amalgam matrix with the formation of porosity even in the bulk of the material. Superposition of the element mappings proved (1) the electrochemical coupling of the amalgam with the silver-based crown, (2) the decalcification of the dentin, and (3) the formation of tin oxychloride precipitates in the matrix porosities and the interfacial gaps. These experimental results corroborate the corrosion mechanisms described hereupon. They support the current national and international recommendations for the dental amalgam formulation and for a rigorous professional practice.

Adult↗
PubMed1975

IgG rheumatoid factor in dental periapical lesions of patients with rheumatoid disease.

To detect "hidden" IgG rheumatoid factor in tissues from dental periapical lesions, 26 rheumatoid and 14 control patients were examined by the direct immunofluorescence technique for binding of FITC-labelled IgG before and after pepsin digestion. Whereas free rheumatoid factor was detected in only 1 rheumatoid tissue before digestion with pepsin, this tissue as well as 8 other rheumatoid tissues strongly bound heat-aggregated IgG after the digestion procedure. Six of these 9 tissues also bound native IgG. In no control tissue was free rheumatoid factor detected and in only 1 was "hidden" rheumatoid factor revealed after pepsin digestion. Hence, presence of IgG rheumatoid factor correlated positively with the presence of rheumatoid disease, and evidence was established that certain features of rheumatoid inflammation occur in dental periapical lesions of many patients with rheumatoid disease.

Adult↗
PubMed1993

A panoramatomographic study of the teeth and jaws of Finnish university students.

A random sample of panoramic radiographs was taken of 1027 (386 male and 641 female) university students. All the students were born between 1965 and 1971. The following were examined: caries, apical radiolucencies, endodontically treated teeth, marginal and vertical bone loss, third molars, supernumerary, missing, and persisting teeth, bone structure, condyles, maxillary sinuses and soft tissue calcifications. In the inter- (of two examiners) and intra-examiner variation Kappa indices varied between 0.15 and 1.00, and agreement percentages from 52, to 100. Kappa index was poor (0.15) in evaluation of the bone structure. The mean DMFT index for the students was 8.4. A sound dentition was found in 6.6%, and 48.4% of the students were free of caries. The mean number of carious lesions was 1.1. There were 50 retained roots (49 from primary teeth). 76.6% of the students had one or more unerupted wisdom teeth and 22.7% had radiologic changes typical of pericoronitis in the region of the mandibular third molars. 16.2% of the students had at least one missing wisdom tooth. Bone structure was normal in 92.4% of the students, idiopathic osteosclerosis being the most common divergence (3.5%). Arthrotic changes in the condyles were found in 9% of the students. In eight cases there was erosion of the condyles, which was diagnosed as arthritis. Styloid ligament calcifications were found in 21.5% of the students. In the maxillary sinuses, male students exhibited changes 1.7 times more often than female students (26.3% in males and 15.1% in females).

Adult↗
PubMed1990

[Follow-up study of the reaction of the marginal and apical periodontium under the continuous application of force].

Radiological findings and clinical data from existing treatment records have been examined using X2-test for clarification of possible relationships between pathological reaction of the periodontal ligament to continuous application of force and different patient-specific and therapeutic factors. It was shown that 70% of the total group have pathological changes following fixed appliance therapy. Apical root resorption usually could be diagnosed five times more frequently than marginal bone loss. No age-specific relationship was noted. The findings confirmed that active intrusion, extensive tooth movement, interruption of treatment, and in particular the anatomical configuration of the roots codetermine the quality of the periodontal reaction.

Adolescent↗
PubMed1996

Expression of inflammatory cytokine genes in vivo by human alveolar bone-derived polymorphonuclear leukocytes isolated from chronically inflamed sites of bone resorption.

Alveolar bone-derived polymorphonuclear leukocytes (PMNs) were characterized for their ability to produce inflammatory cytokines such as interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumor necrosis factor alpha (TNF alpha), and IL-6 in vivo. Periapical exudates (PE) were collected from periapical lesions with chronic periapical periodontitis through root canals. Cells and noncellular supernatants were then isolated by centrifugation. The concentration of cytokines present in the noncellular supernatants were determined by ELISA. High concentrations of IL-1 alpha, IL-1 beta, and IL-6 were detected in PE, however, TNF alpha was not. PE contains predominantly PMNs ( > 95% of residing cells) with a few percent of lymphocytes and/or macrophages. These alveolar bone-derived PMNs were purified by the Ficoll-Hypaque gradient method and were analyzed for cytokine mRNA expression using the cytokine-specific reverse-transcription polymerase chain reaction. Highly purified PMNs ( > 99.5%) isolated from PE expressed significant levels of mRNA for IL-alpha, IL-1 beta, and TNF alpha. IL-6 mRNA was not detected, although a high concentration of IL-6 was detected in supernatants of PE by ELISA. The IL-6 secretion in PE could be derived from macrophages, T lymphocytes, osteoblasts, or fibroblasts around periapical lesions. These data strongly suggest that human PMNs derived from alveolar bone can spontaneously produce IL-1 alpha, IL-1 beta, and TNF alpha at sites of inflammation, and probably initiate inflammation and regulate augmentation of bone resorption in vivo.

Adolescent↗
PubMed1997

Biological aspects of root canal filling materials--histocompatibility,cytotoxicity, and mutagenicity.

In order to minimize the incidence of local and/or systemic side effects, the biocompatibility of all endodontic materials should be investigated by various in vitro and in vivo tests prior to clinical application. The battery of in vitro tests includes determinations of mutagenicity, cytotoxicity, and antibacterial effects. Several reports have shown that paraformaldehyde-containing ZnO-eugenol cements in particular, such as Endomethasone and N2, are antibacterial. On the other hand, it has been found that endodontic materials with strong antimicrobial activity are frequently mutagenic, i.e., primarily those which release formaldehyde. Cell culture tests clearly show significantly different cytocompatibility of the various types of endodontic sealers: in general, formaldehyde-containing ZnO-eugenol cements are classified as highly/extremely cytotoxic, whereas most Ca(OH)2-based sealers are rated as possessing good or excellent cytocompatibility. These results were confirmed by numerous histological studies in vivo. Sealers with inferior biocompatibility, such as formaldehyde-releasing materials, should no longer be applied in practice because safer alternatives are available.

Animals↗
PubMed2001

Application of the Third Molar Eruption Predictor to periapical radiographs.

The aim of this study was to test whether the Third Molar Eruption Predictor, developed for panoramic radiographs, can also be applied to periapical radiographs. The Third Molar Eruption Predictor is a transparent device (US patent 5,816,814), not commercially available, and developed for prediction of future eruption or impaction of third molars. The material consisted of periapical radiographs of mandibular third molars taken from the lateral projection without angulation of the central beam. The radiographs taken at the mean age of 20.6 years (SD +/- 1.4 years) were retrospectively available from a four-year follow-up study of third molars carried out at the University of Copenhagen, Denmark. Initially unerupted or partially erupted third molars (n=43) in 28 dental students were analyzed. Clinical statuses of the third molars were available at baseline and four years later. The device was calibrated using the method of simple proportions and Bayes' Decision Theory. The predictions made with the calibrated device were in conformity with the final clinical outcome in 84% of the cases. It was concluded that the Third Molar Eruption Predictor may also be used on periapical radiographs after calibration of the device.

Adult↗
PubMed1991

The effect of pulpectomy on the longitudinal distribution of nerve fibres in the periodontal ligament of the ferret.

The innervation density of the periodontal ligament was measured at a series of levels around the mandibular canines of 6 ferrets, in 5 of the which the pulp of one of each of these pairs of teeth had been removed 3 months earlier. In control (unoperated) teeth the density of innervation was greatest in the apical third and lowest in the coronal third. The pattern around the pulpectomized teeth was similar. There was no statistically significant difference between density values for control and operated teeth. Pulpectomy thus does not affect the incidence or distribution pattern of nerves in the periodontal ligament.

Animals↗
PubMed1980

Periodontal conditions in patients after molar uprighting.

Fifteen patients who had mandibular molars uprighted unilaterally and seven patients who had mandibular molars uprighted bilaterally were examined an average of 3 1/2 years after treatment had been completed. The investigation focused on differences in clinical observations between the treated teeth and the controls on the contralateral side at the time of the recall examination. Pretreatment radiographs provided longitudinal observations. After elimination of significant but unrelated factors, including surgical pocket elimination and the presence or absence of subgingival margins, the following appeared. Changes in alveolar bone height mesial to the uprighted molars were not different from changes mesial to control teeth. Gingival inflammation scores around uprighted molars were not different from those around control teeth. Pockets mesial to uprighted molars were shallower than those mesial to control teeth. Observations on pocket depth distal to the teeth considered were inconclusive.

Adult↗