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Results for “Periapical Tissue”

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PubMed1992

Biocompatibility of retrograde filling materials in the ferret canine. Amalgam and IRM.

Periapical tissue response to retrograde fillings of amalgam and IRM were compared in the mandibular canine of the adult male ferret. Teeth were cleaned and shaped with a standard technique and obturated with gutta-percha. The root apex was then exposed and retrofillings were placed. The animals were grouped according to observation periods of 5, 10, and 15 weeks. At the proper time the animals were killed and the lower canine tooth along with the surrounding bone was removed. The tissue blocks were examined clinically, radiographed, and prepared for histologic examination. The clinical and radiographic examination indicated both materials to be well tolerated by periapical tissues. Microscopic examination of amalgam specimens showed a decrease in inflammation and the formation of a fibrous capsule over the 15-week period. IRM specimens showed persistent inflammation and slower healing potential.

Alveolar Process↗

PubMed2005

Inflammatory cytokines reaction elicited by root-end filling materials.

Cytokines are inflammation in the list of tissue reactions that cytokines control of cell and tissue growth, development, and differentiation. Root-end filling materials often contact with existing periapical tissue, and they need to be biocompatible with remnant periapical tissue. The aim of this study was to focus the effects of the root end filling materials on bone cell viability and expression of inflammatory cytokines and their role in maintaining health and stability of the restored dental tissues. Calcium hydroxide-based (Life), zinc oxide eugenol-based (Super EBA), and mineral trioxide aggregate-based (MTA) root-end filling materials were used to investigate their effect on a human osteosarcoma cell line (U2OS). The cell attachment assay was observed microscopically, and the expression of interleukin-2, -4, and -10 were quantified by enzyme-linked immunosorbent assay. Any resultant difference between the root-end filling material was analyzed statistically by one-way analysis of variance. The results showed that the best cell attachment to root-end filling material occurred with MTA. The IL-4 (0.824 +/- 0.396) and IL-10 (2.06 +/- 1.24) levels were greater for the MTA group, whereas IL-2 expression for the three kinds of root-end filling materials was similar. All materials were able to induce expression of inflammatory cytokines from cultured bone cells.

Aluminum Compounds↗

PubMed2003

Cytokines in periradicular lesions: the effect of linezolid treatment.

OBJECTIVE: The purpose of this study was to quantify the cytokines interleukin (IL)-1 receptor antagonist (RA), IL-6, and transforming growth factor beta(1) found in extracts of inflammatory periapical tissues and to study the effect of a new antibiotic (linezolid) on the levels of these cytokines. STUDY DESIGN: Twenty-two patients with root-filled teeth with persisting periapical pathoses were randomly divided into a control group or an antibiotic group. One tooth from each of the patients was resected at the root-end, and the periapical tissue was collected. IL-1RA, IL-6, and TGF-beta(1) were quantified in tissue extracts through the use of enzyme-linked immunosorbent assays. RESULTS: Measurable amounts of all 3 cytokines were found in all extracts. A statistically significant reduction in IL-1RA per milliliter was observed in the linezolid group in comparison with the control group (P <.05). The difference in variation of IL-1RA in the treatment and control groups was also highly statistically significant (P <.001). CONCLUSIONS: Although drawn from a limited sample size, the results indicate that IL-1RA is a sensitive indicator of the effect of antibacterial treatment on the immune response in periapical inflammatory tissues.

Acetamides↗

PubMed2002

Regulation of tissue inhibitors of metalloproteinase-1 gene expression by cytokines in human gingival fibroblasts.

Tissue inhibitors of metalloproteinase (TIMP) are important participants in various physiological processes that involve tissues remodeling. They help maintain a delicate balance between physiological degradation and synthesis of the extracellular matrix. A better understanding of TIMP activity will be helpful in understanding the etiology of periapical lesions and their means of treatment. The fibroblast is a prominent cellular component of the periapical tissues. The potential implications of cytokine-mediated tissue destruction still remain to be elucidated. The purpose of this study was to determine the effects of interleukin (IL)-1alpha and transforming growth factor (TGF)-beta on the expressing of TIMP-1 by primary gingival fibroblast cultures. After exposure to cytokines for 8 h, total RNA in gingival fibroblasts was isolated and evaluated by reverse-transcriptase polymerase chain reaction. Densitometric analysis of the TIMP-1 mRNA gene expression, after normalization by beta-actin, demonstrated that exposure to IL-1alpha resulted in a decreased level of TIMP-1 mRNA compared with the control groups. However, the TIMP-1 mRNA was up-regulated by TGF-beta. In addition, when the cells were cultured in combination with TGF-beta (1 ng/ml) and IL-1alpha for 8 h, the level of TIMP-1 mRNA was dramatically reduced. These results demonstrated that in human periapical tissue cytokines differentially and specifically regulate expression of TIMP-1 mRNA. An understanding of the actions of cytokines on gingival fibroblasts may result in new therapies to augment current treatment of periapical lesions.

Cells, Cultured↗

PubMed2004

[Animal test of nHA-PA66 used in root canal filling].

OBJECTIVE: To assess the dogs' tissue reaction to nHA-PA66 which is prepared to be used as a new root canal filling sealer. METHODS: The experimental apical periodontitis of dogs was induced first, then nHA-PA66 was used in the test groups while CCQ was used in the control group. The reactions of periapical tissues were measured by histological means. RESULTS: One month after nHA-PA66 was used in root canal filling, the dogs' periapical tissues showed mild to moderate inflammatory reactions, the X-ray films showed decreased radiolucent area as compared with the previous film. Three months later, tissue repairs occurred, which exhibited even more decreased radiolucent area on X-ray films. nHA-PA66 caused weak inflammatory reaction while the reparative reaction happened early. CONCLUSION: nHA-PA66 has good tissue compatibility and is a potential sealer for root filling in clinical use.

Animals↗

PubMed1975

Periapical actinomycosis.

Two cases of actinomycotic lesions of the periapical tissue in relation to the molars are described. The difficulty in obtaining a positive culture for actinomycetes in spite of definite histologic evidence of actinomycosis is highlighted. Besides antibiotics, the importance of planned treatment to deal with the underlying diseased periapical tissue and the tooth is emphasized.

Actinomycosis, Cervicofacial↗

PubMed1997

EDTA inhibits in vitro substrate adherence capacity of macrophages: endodontic implications.

The disodium salt of ethylenediamine tetraacetate (EDTA) is a calcium ion chelator used in endodontics to enlarge root canals. This study investigated the effect of EDTA on substrate adherence capacity of rat inflammatory macrophages to determine if EDTA leakage to periapical tissues during root canal therapy can alter macrophage function. Inflammatory macrophages were obtained from Wistar rats and resuspended in RPMI-1640 medium. Substrate adherence capacity assays were carried out in Eppendorf tubes for 15 min of incubation at 37 degrees C in a humidified atmosphere of 5% CO2. The adherence index (AI) was calculated. Results showed that EDTA decreased substrate adherence capacity of inflammatory macrophages in a time and dose-dependent manner. The lowest EDTA concentration that caused a significant inhibition of AI was 50 mM (p < 0.05), and the EDTA concentration that caused half-maximal inhibition (IC50) was 194 +/- 20 mM (p < 0.01). Calcium chloride (10 mM) increased the adherence index of macrophages by 17.1% (p < 0.05) and decreased the EDTA inhibitory effect on AI by 49.5% (p < 0.05). We conclude that an EDTA concentration lower than that used in endodontics decreased the substrate adherence capacity of macrophages significantly. Adhesion is the first step in the phagocytic process and in antigen presentation, but leakage of EDTA to periapical tissues during root canals preparation may inhibit macrophage function and reduce periapical inflammatory reactions.

Animals↗

PubMed2006

Co-production of vascular endothelial cadherin and inducible nitric oxide synthase by endothelial cells in periapical granuloma.

AIM: To clarify the mechanisms of inflammatory cell migration in human periapical granulomas by examining vascular endothelial (VE) cadherin and inducible nitric oxide synthase (iNOS)-producing cells. METHODOLOGY: Periapical tissues were obtained from patients during endodontic surgery and were divided into two portions. After fixing the tissues with acetone or 4% paraformaldehyde in phosphate-buffered saline, 5-microm-thick paraffin or cryostat sections were prepared, respectively. The paraffin sections of the inflamed tissues were evaluated histologically with haematoxylin-eosin stains. Cryostat sections of the tissue, diagnosed as periapical granulomas, were then examined by either immunohistochemistry using anti-human VE-cadherin or iNOS antibodies (Abs) for the characterization of infiltrating cells. In addition, co-localization of VE-cadherin and iNOS production was also analysed by two-colour immunofluorescence image analysis. RESULTS: Endothelial cells were strongly stained with iNOS Abs. Macrophages, lymphocytes, polymorphonuclear leucocytes and fibroblasts also exhibited iNOS production. These iNOS-positive cells accumulated around the blood vessels. On the other hand, VE-cadherin production was exhibited in only endothelial cells. Two-colour immunofluorescence image analysis using VE-cadherin and iNOS Abs demonstrated that iNOS-producing endothelial cells also showed VE-cadherin production. CONCLUSIONS: Vascular endothelial-cadherin produced by endothelial cells could be regulated by iNOS-producing cells in periapical granulomas and might play a pivotal role in vascular permeability.

Adult↗

PubMed1997

Use of calcium hydroxide for apical barrier formation and healing in non-vital immature permanent teeth: a review.

OBJECTIVE: To review the use of calcium hydroxide for induction of apical barrier formation and healing in immature permanent teeth. INTRODUCTION: Pulp necrosis is a frequent complication of dental trauma in immature permanent teeth. Endodontic treatment of these teeth is often complicated. The walls of the root canals are frequently divergent and the apices immature, making debridement and obturation difficult. The aim of treatment is induction of apical healing which may be defined as apical closure through formation of mineralised tissue and repair of the periapical tissues. Calcium hydroxide is the material of choice for apical barrier formation and healing. RESULTS: The use of calcium hydroxide for apical barrier formation is successful in 74-100% of cases irrespective of the proprietary brand used. The average length of time for apical barrier formation is approximately 5 to 20 months. Control of infection and adequate cleaning of the root canal are very important for apical healing. CONCLUSIONS: While the success rate of apical barrier formation using calcium hydroxide is high, long-term follow-up of these teeth is necessary. Problems such as failure to control infection, recurrence of infection and cervical root fracture may occur. The latter is more frequent in immature luxated teeth with the least root development.

Bacterial Infections↗

PubMedDate not supplied

[Subtotal vital pulp extirpation using different medical preparations (experimental morphological research)].

Pulp stump and periapical tissue reaction to root canal filling with material containing calcium hydroxide and potassium nitrate after subtotal vital extirpation of the pulp was studied in 12 teeth of 6 green monkeys. Use of the material containing potassium nitrate was found to result on the 90th day of the experiment in the formation of a biologic barrier of secondary cement at the dental root apex. Such result was not achieved with calcium hydroxide-containing material. Other advantages of potassium nitrate-containing material were detected, consisting in a more rapid recovery of structural shifts in the pulp stump and periapical tissues.

Animals↗

PubMed2000

Assessment of periradicular microbiota by DNA-DNA hybridization.

In the present study the "checkerboard" DNA-DNA hybridization technique was used to identify bacteria in periapical endodontic lesions of asymptomatic teeth. Thirty-four patients with root-filled teeth and apical periodontitis were divided into two groups, each containing 17 patients. In Group 1, a marginal incision was performed during surgery to expose the lesion, and in Group 2, a submarginal incision was applied. The gingiva and mucosa were swabbed with an 0.2% chlorhexidine gluconate solution prior to surgery. Bacterial DNA was identified in all samples from the two groups using 40 different whole genomic probes. The mean number (+/- SD) of species detected was 33.7 +/- 3.3 in Group 1 and 21.3 +/- 6.3 in Group 2 (P < 0.001). The majority of the probe-detected bacteria were present in more lesions from Group 1 than from Group 2. The differences were most notable for Campylobacter gracilis, Porphyromonas endodontalis, Propionibacterium acnes, Capnocytophaga gingivalis, Fusobacterium nucleatum ssp. nucleatum, Fusobacterium nucleatum ssp. polymorphum, Prevotella intermedia, Treponema denticola, Streptococcus constellatus and Actinomyces naeslundii I. Bacterial species such as Actinobacillus actinomycetemcomitans and Bacteroides forsythus were detected in more than 60% of the lesions from both groups. Also, P. endodontalis was abundant in periapical tissue. The data supported the idea that following a marginal incision, bacteria from the periodontal pocket might reach the underlying tissues by surgeon-released bacteremia. The study provided solid evidence that bacteria invade the periapical tissue of asymptomatic teeth with apical periodontitis. The detection of much more bacteria with the "checkerboard" DNA-DNA hybridization method than has previously been recovered by anaerobic culture indicated that the endodontic (and periodontal) microfloras should be redefined using molecular methods.

Actinomyces↗

PubMed2001

Histological evaluation of electrosurgery and formocresol pulpotomy techniques in primary teeth in dogs.

The purpose of this study was to compare pulpal and periapical tissue reactions to electrosurgery versus formocresol pulpotomy techniques in the primary teeth of dogs. The study was conducted on 33 primary teeth of three mongrel dogs between the ages of one to three months. Each dog had three teeth treated by Formocresol Pulpotomy with Mechanical Coronal Pulp Removal (FC), three teeth treated by Electrosurgery Pulpotomy with Mechanical Coronal Pulp Removal (ES/MCPR), three teeth treated by Electrosurgery Pulpotomy with Electrosurgical Coronal Pulp Removal (ES/ECPR), and two teeth serving as untreated Controls. Dogs one, two and three were sacrificed performing the pulpotomies at two, four and six weeks, respectively. The pulp, periapical tissue and after surrounding bone were submitted to histological examination and the histological reaction was recorded. The results were fourteen out of 18 unfavorable and zero out of three favorable histological reactions occurred in the FC treated teeth. Six out of 18 unfavorable and one out of three favorable histological reactions occurred in the ES/MCPR treated teeth. Nine out of 18 unfavorable and two out of three favorable histological reactions occurred in the ES/ECPR treated teeth. One out of 18 unfavorable and zero out of three favorable histological reactions occurred in the untreated Control teeth. The conclusion of this study is that of the three experimental groups, the teeth treated by Electrosurgery Pulpotomy with either Mechanical or Electrosurgical Coronal Pulp Removal exhibited less histopathological reaction than the teeth treated by Formocresol Pulpotomy.

Animals↗

PubMed1996

Incomplete healing (scar tissue) after periapical surgery--radiographic findings 8 to 12 years after treatment.

Twenty-four cases treated by periapical surgery--which 2 to 6 yr after surgery were classified radiographically as incomplete healings (scar tissue)--were further followed, extending the observation period to 8 to 12 yr. One case healed completely, 1 failed, and 22 were still recorded in the same healing group. All the 22 scar tissue cases were characterized by a reduction of the defect in bone. In 13 cases, continuous periodontal structures were seen and the defect thereby separated from the root. The findings support the conclusion that cases clearly showing features of incomplete healing (scar tissue) at the regular follow-up 1 yr after surgery can be regarded as successes. They need not be recorded for further systematic control. A general follow-up program for apicectomy cases is suggested.

Apicoectomy↗

PubMed1982

Circulating antibodies after experimental chronic infection in the root canal of teeth in monkeys.

Root canals of 49 teeth with necrotic pulp tissue in five monkeys were infected with Streptococcus faecalis ss liquefaciens, Actinomyces bovis, Fusobacterium nucleatum, Peptostreptococcus anaerobius, and Bacteroides oralis in various combinations. After 6 months the root canals and the periapical tissues were subjected to radiographic, bacteriologic, and histologic examinations. Signs of periapical inflammation were radiographically registered in 41 teeth, most frequently in teeth inoculated with a mixed flora. In 11 out of 16 teeth infected separately with Strep. faecalis ss liquefaciens, apical periodontitis was observed. Sera from the monkeys prior to and after the experimental inoculation were analyzed by means of gel diffusion, hemagglutination (HA), and complement binding test for antibodies against different antigen preparations of the homologous bacterial strains used for the inoculation. Detectable antibodies were seen with antigens of B. oralis in all five monkeys. Agglutinating antibodies were demonstrated with lipopolysaccharide-antigen of B. oralis in titers between 1:40 and 1:320. A marked reduction of the antibody level against lipopolysaccharide (LPS) antigen after mercaptoethanol treatment indicated that a main part of the antibodies registered was of IgM-class. The study shows that certain antigens of bacterial origin from infected root canals, while affecting the periapical tissues, also stimulate the production of circulating antibodies.

Animals↗

PubMed1989

[Immunopathologic mechanisms associated with granulomas and odontogenic cysts: a general review].

The authors make a general survey of the immunopathological mechanisms involved in odontogenic cysts and granulomas. The dental pulp and the sound periapical tissues contain neither inflammatory nor immunoglobin-producing cells. Dental decay associated with bacterial aggression of the dental pulp and periapical tissues might induce a nonspecific inflammation which subsequently becomes more specific. Immunoglobulins are present in fluid aspirates from odontogenic cysts and granulomas. Several investigations have pointed out nonspecific inflammatory mediators (including the C3 complement components), T lymphocytes (helpers and suppressors), B lymphocytes, protein S-100 + cells (Langerhans cells). The presence of immunoglobulins, immunocompetent cells and C3 complement components confirms that all constituents of both humoral and cell-mediated immunological reactions might play an essential role in the pathogenesis of osteolysis.

Humans↗

PubMed1990

Tissue response to glass ionomer retrograde root fillings.

The periapical tissue response to glass ionomer cement retrograde root fillings was investigated both in the presence and in the absence of fillings in the root canals of eight upper incisor teeth of four monkeys. The pulps of the teeth were extirpated and one canal in each pair was filled with laterally condensed gutta-percha immediately after canal preparation. The other canal was prepared but left open to oral contamination. Apicectomies were performed on both teeth in each pair 1 week later, and glass ionomer cement retrograde root fillings were placed. After 5 months, the teeth and surrounding tissues were removed and prepared for histological examination. All four of the teeth without root canal fillings showed severe periapical inflammation, and bacterial were present in the interface between the dentine and the retrograde root filling. The teeth with root canal fillings showed little or no periapical inflammation. This study showed that adhesive retrograde root fillings were successful when the root canal was completely filled, but in the absence of a gutta-percha canal filling they failed to provide a seal.

Animals↗

PubMed1997

Electrical impedance measurements of root canal length.

Electronic methods are now widely used during endodontic treatment for the assessment of root canal length. These commonly measure the electrical resistance or impedance between the root canal and the buccal mucosa. A number of studies have been undertaken to determine the accuracy of commercially available instruments. The aims of this investigation were to determine the electrical impedance characteristics of the root canal and periapical tissues in vivo, measure the changes relative to the distance of an endodontic instrument from the apical constriction and propose an equivalent circuit modelling the periapical tissues. The length of the root canals of 20 previously untreated teeth were determined using radiographic and electronic methods. Minimal canal preparation was carried out and measurements were made with a size 10 K-Flex file. A microprocessor-controlled LCR analyser was used to measure the electrical impedance characteristics of each root canal. The instrument measured the series and parallel resistive (RS, RP) and capacitance (CS, CP) component of the tissues at two test frequencies, 100 Hz and 1 kHz. Measurements were made for each root canal when the diagnostic file was placed at the apical constriction and repeated when the file was withdrawn to -0.5, -1.0, -1.5, -2.0 and -5.0 mm from the foramen. Readings were taken for each canal after the canal had been dried with paper points, and flooded first with deionised water and then with sodium hypochlorite. The root canals were then prepared, cleaned and obturated using standard endodontic procedures. The LCR analyser selected the series resistance component as the major measurement parameter. There was a clear increase in series resistance (RS) with increasing distance from the radiographic apex for dry canals and those containing deionised water and sodium hypochlorite. The mean resistance for dry canals was markedly higher than for those containing fluid, ranging from 22.19 k omega to 92.07 k omega in comparison with 9.32 k omega to 12.10 k omega for deionised water and from 7.46 k omega to 8.92 k omega for canals containing sodium hypochlorite. There was a marked change in the series and parallel resistive component with distance from the apex, suggesting a complex relationship between the impedance of the smear layer and bulk dentine. The impedance characteristics of a root canal were a complex electrical network comprising resistive and capacitive series and parallel elements.

Dental Pulp Cavity↗

PubMed2003

Tissue reaction initiated by different sealers.

AIMS: To analyse the type and degree of inflammatory reaction initiated by four sealers. METHODOLOGY: Twenty-four root canals of Macaca mulatta monkeys were filled within the canal and eight were overfilled with AH26, Apexit, Endomethasone or Grossman's sealers. The result of the treatment was evaluated after 6 months by histological assessment of the periapical tissues. RESULTS: In the group of root canals filled within the root, no inflammatory reaction was detected in specimens of Apexit and Grossman's sealers, but the other two sealers initiated different degrees of lymphocytic/plasmocytic tissue reactions. Endomethasone initiated a mild lymphocytic/plasmocytic reaction in three of the nine cases and AH26 caused mild lymphocytic/plasmocytic infiltration in two of the seven cases. In the group of overfilled root canals, all four sealers initiated inflammatory reactions. The periapical tissue reactions of overfilled root canals were similar to reactions detected in cases filled within the canal. However, additional histological features developed in specimens of Endomethasone and AH26: Endomethasone initiated a foreign body-type granulomatous reaction around the sealer particles and AH26 particles were engulfed by macrophages. The overfilled root canals of Apexit and Grossman's sealers initiated only lymphocytic/plasmocytic reactions. CONCLUSIONS: This study suggests that sealers with different chemical compositions initiate different histological reactions. It also emphasizes the importance of confining root filling to the canal system because all sealers initiate inflammatory reactions when they are present in the apical tissues

Administration, Topical↗