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At least 235 records · Page 13Linked to original sources
PubMed2003

Removal of organic debris from bovine dentin shavings.

A common problem with root canal failures is chronic inflammation at the apex caused by overfilling of root canal materials. Dentin filings have been suggested as an apical plug to create a biocompatible barrier between the filling material and the periapical tissue. Unfortunately residual organic material, such as pulp remnants or bacteria, still may be part of the filings. Dentin filings removed from the tooth, cleaned, and then used to form a barrier might serve as an effective barrier. The purpose of this study was to evaluate methods of cleaning dentin of organic debris. NaOCl, sodium dodecyl sulfate, and 1% Triton X-100 were used to treat dentin shavings and were evaluated by a micro bicinchoninic acid protein analysis assay. Two series of experiments were performed. One compared the effect of temperature while using phosphate-buffered saline as a control and the second compared exposure times. The percentage of protein extracted from dentin samples increased with temperature. Sodium hypochlorite at room temperature extracted 24.6%, NaOCl at 37 degrees C extracted 26.9%, and NaOCl at 70 degrees C extracted 33.9%. Only NaOCl at 37 degrees C and 70 degrees C showed statistically significant differences from phosphate-buffered saline at room temperature with p-values of 0.028 and 0.019, respectively. The exposure time series showed a difference between a phosphate-buffered saline solution and 6.25% NaOCl. NaOCl removed approximately 90% of protein compared with 60% for the phosphate-buffered saline. A 10-min exposure to 70 degrees C 6.25% NaOCl may be an efficient means of removing organic material from dentin shavings.

Animals↗
PubMed1992

Tissue response following CO2 laser application in apical surgery: light microscopic assessment in dogs.

The potential advantages of CO2 laser in apical surgery have not been established histologically. Therefore, the long-term effects of CO2 laser on the apical and periapical tissues were examined histologically in dogs 6 months after apical surgery. Lased specimens and unlased controls showed periapical inflammatory and osteogenic reactions. Lased root surfaces revealed craters with a superficial charred layer closely associated with new cementum-like matrix. The subjacent dentin appeared tubule-free and eosinophilic. Lased bone trabeculae showed a charred layer with a deeper osteocyte-free zone. The charred layer was covered by new bone. Detached charred segments in the marrow space and periapical inflammatory infiltrate were intimately associated with multinucleated giant cells, some containing minute char particles. Such cells were absent from the root and trabecular char linings. In addition, the charred surfaces were free of hard tissue resorption. These results suggest that CO2 laser does not hinder healing when applied in apical surgery.

Alveolar Process↗
PubMed1998

Inflammation-associated lysyl oxidase protein expression in vivo, and modulation by FGF-2 plus IGF-1.

Lysyl oxidase is the extracellular enzyme that catalyzes oxidative deamination of peptidyl-lysine residues in elastin precursors, and lysine and hydroxylysine residues in collagen precursors to form peptidyl-aldehydes. These aldehydes then spontaneously condense to crosslink collagen and elastin and thereby allow the formation of a mature and functional extracellular matrix. In the present study, cryosections made from aseptic immune-induced periapical lesions experimentally generated in laboratory rats were examined by immunohistochemistry to investigate whether lysyl oxidase protein expression is altered in inflamed oral tissues. Periapical lesions are experimentally induced endodontic lesions of tooth roots. In addition, the effect of administration of a mixture of fibroblast growth factor (FGF)-2 and insulin-like growth factor (IGF)-1 into these lesions on lysyl oxidase expression was determined. Lysyl oxidase expression was found to be increased in non-mineralized connective tissue adjacent to inflamed lesions. Morphometric analyses indicated that maximum lysyl oxidase expression occurred at a discrete distance from the lesion not exceeding 350 microm from the inflammatory cells. Staining was associated with mesenchymal cells with a fibroblastic morphology. No lysyl oxidase staining was found near teeth where no lesion was induced. Application of a mixture of FGF-2 and IGF-1 resulted in a further twofold increase in lysyl oxidase expression. These results provide a new in vivo model to study lysyl oxidase regulation, and suggest that inflammatory cells may control lysyl oxidase expression in oral tissues, possibly by a mechanism involving secretion of cytokines and other factors, probably contributing to the regulation of extracellular matrix accumulation.

Animals↗
PubMedDate not supplied

Tissue-space emphysema, tissue necrosis, and infection following use of compressed air during pulp therapy: case report.

The intraoperative development of tissue-space emphysema in a child undergoing restorative treatment under general anesthesia is presented. Emphysema development seems to be concomitant with the use of compressed air around patent root canals, complicated by tissue destruction due to movement of canal irrigants/medicaments into the periapical tissues and by secondary infection. Several recommendations for the prevention of tissue-space emphysema are presented including the use of a rubber dam, judicious use of compressed air, and maintenance of canal irrigants and medicaments within the root canal. Treatment recommendations vary from palliative care with follow up in cases of facial emphysema to immediate medical attention in cases of pharyngeal or mediastinal emphysema.

Abscess↗
PubMed2003

Induction of tissue plasminogen activator gene expression by proinflammatory cytokines in human pulp and gingival fibroblasts.

Plasminogen activator converts plasminogen to plasmin, and plasmin activates the latent matrix metalloproteinases. Tissue plasminogen activator (t-PA) is one of the important proteolysis factors present in human inflamed tissues. However, few studies reported on the mechanisms of tissue destruction via a t-PA proteolysis pathway in pulpal and periapical diseases. The subsequent reactions leading to pulpal and periapical injury after the induction of proinflammatory cytokines remains to be elucidated. The aim of this study was to investigate the effects of interleukin-1alpha and tumor necrosis factor-alpha on the expression of t-PA mRNA gene in cultured human pulp and gingival fibroblasts. The mRNAs for t-PA were measured by reverse transcription-polymerase chain reaction at 2, 6, and 24 h. The results show that both cytokines induced significantly high levels of t-PA mRNA gene expression in human pulp fibroblasts. The peak of t-PA mRNA levels induced by both proinflammatory cytokines was at the 6-h incubation period. Interleukin-1alpha was found to be more effective in induction of t-PA gene expression than tumor necrosis factor-alpha. In addition, a similar induction pattern was also found in human gingival fibroblasts. These results indicate that proinflammatory cytokines can induce t-PA gene expression and such an effect may partially contribute to the destruction of pulpal and periapical tissues through dysregulated pericellular proteolysis. An understanding of the mechanism could not only further define the role of immune events in pulpal and periapical diseases but also have important implication for pharmacological intervention.

Cells, Cultured↗
PubMed1995

Abscess formation around the apex of a maxillary root form implant: clinical and microscopical aspects. A case report.

This case report describes the occurrence of an abscess in the periapical area of a root form maxillary titanium implant, with a radiolucent appearance and purulent discharge. The removal of the infected periapical tissues was carried out but the clinical symptoms of infection persisted, an attempt at guided tissue regeneration with a freeze-dried dura mater membrane notwithstanding, and it was necessary to remove the implant. The microscopical examination showed that it was possible to observe nonviable bone tissue, with absence of bone cells and areas of bone resorption in the apical portion of the implant. These microscopical features were compatible with an acute localized suppurative osteomyelitis.

Adult↗
PubMed1992

Usage test of four endodontic sealers in Macaca fascicularis monkeys.

Root canals with vital pulps in four Macaca fascicularis monkeys were subjected to pulp extirpation and root filling with gutta-percha and sealer, either AH26, Endomethasone, Kloroperka N-phi, or ProcoSol. Observation periods were 1 and 6 months. The results of treatment were evaluated by radiographic analysis (periapical index scores) and by histopathologic assessment of the remaining pulp and periapical tissues. Sixty roots with acceptable termination (between 0.5 and 3 mm from apex) of the root fillings and adequate histopathologic specimens were available for analysis. These roots were equally distributed in each observation period group and among the four material groups. Radiography indicated periapical pathosis in 6 of the 60 roots--4 at 1 month and 2 at 6 months. Periapical inflammation was observed on histopathologic examination in 17 roots--11 after 1 month and 6 after 6 months. Histologic and radiographic assessment of periapical inflammation was significantly correlated (p less than 0.01, chi 2) at the 6-month observation period. No granuloma or cyst formation was evident on histologic examination. The magnitude of the inflammatory response appeared unrelated to the endodontic sealer used, and several inflammatory foci were not related to foreign bodies in the tissues. Bacteriologic sampling showed growth in thioglycollate broth cultures in 9 of the 60 roots, but the presence of cultivable bacteria by this technique was unrelated to inflammatory changes. Histologic demonstration of bacteria was positive in 4 roots, all of which were associated with inflammatory periapical reactions. The method applied in the present study did not provide a sensitive discrimination among endodontic materials of widely different chemical composition.

Administration, Topical↗
PubMed1992

Biologic properties of eugenol and zinc oxide-eugenol. A clinically oriented review.

Eugenol-containing dental materials are frequently used in clinical dentistry. When zinc oxide-eugenol (ZOE) is applied to a dentinal cavity, small quantities of eugenol diffuse through the dentin to the pulp. Low concentrations of eugenol exert anti-inflammatory and local anesthetic effects on the dental pulp. Thus use of ZOE temporary filling may facilitate pulpal healing; on the other hand, high eugenol concentrations are cytotoxic. Direct application of eugenol to pulp tissue may result in extensive tissue damage. The ability of ZOE-based endodontic sealers to influence periapical tissue healing is considered in view of eugenol's anti-inflammatory and toxic properties.

Biocompatible Materials↗
PubMed2002

The effect of fish oil on bone resorption following pulp exposure in rats.

The aim of this study was to determine whether treatment with fish oil may alter the periapical bone resorption following pulp exposure in rats. Untreated and pulp-exposed animals served as the negative and positive control, respectively. Other pulp-exposed animals were orally treated with fish oil at different concentrations and frequencies. Periapical tissue sections were stained with tartrate-resistant acid phosphatase (TRAP), and then the numbers of both periapical osteodasts and preosteoclasts were determined. The levels of bone resorption were assessed using the osteoclast-bone interface (OBI) index. The results showed that no differences between the numbers of both osteoclasts and preosteoclasts in the fish oil-treated animals and the negative control at day 14 could be found. Similarly, the periapical bone resorption in the animals treated with fish oil for 14 days significantly reduced to the levels of that in the negative control. The results of the present study, therefore, suggest that oral treatment with fish oil may inhibit bone resorption following pulp exposure in rats and hence, may have a therapeutic modality for inflamed periradicular tissue.

Alveolar Bone Loss↗
PubMed1990

Factors affecting the long-term results of endodontic treatment.

The influence of various factors that may affect the outcome of root canal therapy was evaluated in 356 patients 8 to 10 yr after the treatment. The results of treatment were directly dependent on the preoperative status of the pulp and periapical tissues. The rate of success for cases with vital or nonvital pulps but having no periapical radiolucency exceeded 96%, whereas only 86% of the cases with pulp necrosis and periapical radiolucency showed apical healing. The possibility of instrumenting the root canal to its full length and the level of root filling significantly affected the outcome of treatment. Of all of the periapical lesions present on previously root-filled teeth, only 62% healed after retreatment. The predictability from clinical and radiographic signs of the treatment-outcome in individual cases with preoperative periapical lesions cases was found to be low. Thus, factors which were not measured or identified may be critical to the outcome of endodontic treatment.

Dental Pulp Diseases↗
PubMed1993

Histological evaluation of therapy using a calcium hydroxide dressing for teeth with incompletely formed apices and periapical lesions.

Periapical tissue response was evaluated histologically in teeth of 6-month-old dogs with incomplete root formation and periapical lesions in order to compare the effects of two calcium hydroxide-containing pastes prepared with different vehicles on induced root apex formation and repair of the periapical region. A group of teeth with no root canal dressing was used as control. After induction of the periapical lesion, the root canals were instrumented and filled with one of the two pastes (Calen and Calasept), which were renewed monthly for 90 days. At the end of the follow-up period (3 months), the animals were killed. Block sections from the actual areas were dissected free and prepared for histopathological analysis. Both calcium hydroxide pastes helped induce apical sealing and repair of the region, but the Calen paste yielded better results than Calasept. The induced mineralized tissue was predominantly of the cementoid type after the use of both pastes, but the inflammatory infiltrate was significantly less intense with the use of the Calen paste. In the control group, the absence of a root canal dressing impaired the process of periapical repair and yielded no apical root closure in any of the cases analyzed.

Animals↗
PubMedDate not supplied

Alteration of monocytic cell oxidative burst caused by methacrylic monomers present in dental materials: a chemiluminescence study.

Methacrylates are present in dental composite resins used in clinical practice. Methacrylates are photo-polymerized, but this reaction is never complete, so release of uncured monomers in the periapical tissues and in biological fluids may happen and, potentially, alter the repair of pulpal and of periapical lesions by interfering with local phagocytes. The aim of this study was the evaluation of the functional activity of the monocyte-macrophage system after incubation with methacrylic monomers. The oxidative burst of two cellular systems was analysed using the chemiluminescence technique. Data were collected and statistically analysed. Monomers were found to reduce the in vitro oxidative burst of phagocytes independently from their cytotoxicity. These findings demand further evaluation of the effects of oxidative burst alteration in monocyte-macrophage function and may prompt the inclusion of the described chemiluminescence test in biocompatibility preliminary studies of dental materials.

Cell Survival↗
PubMed1990

Therapy-resistant foreign body giant cell granuloma at the periapex of a root-filled human tooth.

Although the primary etiological factor of periapical lesions is microbial, there are other independent factors that can adversely affect the outcome of endodontic treatment. In this communication, we present morphological evidence in support of the role of a foreign body reaction of periapical tissue to root-filling materials. The specimen consisted of a surgical biopsy of an asymptomatic periapical lesion which persisted after a decade of postendodontic follow-up. The biopsy was processed for correlated light and electron microscopy and was analyzed by various microtechniques. The unique feature of the lesion was the presence of vast numbers of large multinucleated cells and their cytoplasmic inclusion bodies. Morphologically, these multinucleated cells resembled foreign body giant cells. They contained characteristic birefringent cytoplasmic inclusions which on electron-probe X-ray microanalysis consistently revealed the presence of magnesium and silicon. The magnesium and silicon are presumably the remnants of a root-filling excess which protruded into the periapex and had been resorbed during the follow-up period. These observations strongly suggest that in the absence of microbial factors, root-filling materials which contain irritating substances can evoke a foreign body reaction at the periapex, leading to the development of asymptomatic periapical lesions that may remain refractory to endodontic therapy for long periods of time.

Biopsy↗
PubMed1991

Histologic studies on the extension of the inflammatory infiltrate in human periodontitis.

This study was undertaken to re-examine early and recent morphologic descriptions of gingival and periodontal inflammation based on a study of gingival biopsies and block sections of human jaws. A collection of 350 autopsy and surgically retrieved jaw sections containing multiple teeth and displaying various stages of periodontal inflammation were subjected to routine histologic preparation and analyzed with step serial sections. 105 gingival biopsies, serially sectioned, including 15 clinically normal specimens, were also studied. The results of these investigations suggest that the inflammatory lesion extends into the alveolar process and elicits a response, often before evidence of crestal resorption or connective tissue attachment loss has occurred. Similarly, deep penetrations of inflammatory cells into the alveolar bone, periodontal ligament and periapical tissues, along with fibrosis and enlargement of the marrow spaces, were common findings with advancing disease. More widespread distributions of inflammatory cells than previously described were found in clinically normal gingiva, while in more inflamed gingiva, the inflammatory cell types found and their pattern of distribution varied greatly from individual to individual. These observations cast doubt on the perception of human periodontitis as a localized and marginal disease and suggest that its effects may be much more pervasive than previously thought.

Adult↗
PubMed1985

A suggested role for polymorphonuclear leukocytes in the perpetuation of periapical disease.

During the course of an investigation of endodontic materials using subcutaneously implanted human roots in rats and guinea pigs, it was noted that in areas of the root canal which had not been reamed polymorphonuclear leukocytes had migrated into the dentinal tubules. It is suggested that irritation of the periapical tissues may be mediated by these polymorphonuclear leukocytes. Therefore, the occlusion of dentinal tubules which may be exposed to periapical exudate may be of prime importance in endodontic treatment.

Animals↗
PubMed2005

Intraosseous injection of clindamycin phosphate into the chronic apical lesion of lower molar--a case report.

Periapical disease is the result of bacteria, their product, and the host response to them. Early histological studies of diseased periapical tissue have not been able to demonstrate viable bacteria in the lesions studied. Recent reports indicate that many of periapical lesions are indeed infected before and after endodontic treatment. The validity and applicability of the microbial delivery overcome many disadvantages that we see with systemic drugs. In this case report we presented a novel approach of managing chronic diffuse periapical lesion of lower molar based on specific selection of intracanal medicament in combination with direct periapical injection. We used bacterial culturing and antibiotic sensitivity test to select specific intracanal medicament, in addition we presented an intraosseous injection technique to locally deliver the selected medicament directly into the periapical lesion. Our findings are encouraging and promising. The validity and applicability of the technique needs to be tested in a well controlled clinical trial.

Adult↗
PubMed1995

Dens invaginatus of a mandibular central incisor: surgical endodontic treatment.

Dens invaginatus is a developmental malformation that mostly affects maxillary lateral teeth and mandibular teeth are rarely affected. In this paper a mandibular central incisor with a dens invaginatus is identified as requiring both endodontic and surgical treatment is presented. At one year recall appointment satisfactory clinical and radiographic healing was evident. This case demonstrates that also periapical surgery should be performed in some cases with dens invaginatus for resolution of periapical tissues.

Child↗