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PubMed1996

Periapical lesions in rats with streptozotocin-induced diabetes.

The purpose of this study was to investigate histologically and histometrically the changes in pulpal periapical tissues after pulpal exposure in streptozotocin-induce diabetic rats. Control rats were injected with citrate buffer. Experimental rats were injected with streptozotocin dissolved in citrate buffer. All animals received a pulpal exposure in the left mandibular first molar. Blood glucose concentration was measured at, 0, 7, 14, 28, and 42 days. All animals were killed at 7, 14, 28, and 42 days after pulpal exposure, and their mandibles were evaluated histologically and histometrically. Blood glucose levels in the experimental rats were significantly higher than those in the control rats. In experimental rats, inflammation in the apical periodontal ligament and root resorption and alveolar bone resorption were more severe than that in control rats. This study also revealed histometrically that, in experimental rats, lesions in the periapical area were significantly larger than those in control rats.

Alveolar Bone Loss↗
PubMed1999

Inducible nitric oxide synthase activity by interferon-gamma-producing cells in human radicular cysts.

AIM: In this study, the interaction of interferon-gamma-(IFN-gamma) and inducible nitric oxide synthase (iNOS)-producing cells in human radicular cysts were investigated. METHODOLOGY: Inflamed periapical tissues were obtained from patients at the time of endodontic surgical treatments and were cut into two pieces. After fixing with acetone or 4% paraformaldehyde in phosphate-buffered saline, 5-m-thick paraffin and cryostat sections were prepared. The paraffin sections of the inflamed tissues were evaluated histologically with haematoxylineosin stains. The specimens diagnosed as radicular cysts were then examined by immunostaining. Immunohistochemistry for iNOS and fluoresence microscopy for IFN-gamma using the cryostat sections were performed with a mixture of affinity purified human iNOS antiserum and human IFN-gamma monoclonal antibodies. RESULTS: The results revealed that iNOS-gamma producing cells localized adjacent to IFN-gamma-producing cells. In addition, some of iNOS-producing cells exhibited immunoreactive IFN-gamma. On the other hand, epithelial cells showed significant levels of iNOS production, but not IFN-gamma. CONCLUSIONS: The data would suggest the possibility that iNOS production could be precisely controlled by autocrine or paracrine effects of IFN-gamma producing cells in radicular cysts and might play a pivotal role in periapical lesions. These findings are consistent with a hypothesis suggesting that NO inhibitors could be used through the root canals as a pharmacological treatment for periapical lesions.

Adult↗
PubMed1994

Chronic pain associated with a foreign body left under the soft tissue flap during periapical surgery.

A case is reported of a patient who requested treatment for chronic pain of 7 yr duration. After several unsuccessful endodontic procedures, a cotton pellet was discovered under the soft tissue near the apex of the left maxillary cuspid. It was theorized that the cotton was left under the tissue flap during a previous apicoectomy procedure. After the cotton was removed the patient subsequentially reported that the pain was relieved.

Adult↗
PubMed1992

Immunochemical and biological characterization of outer membrane proteins of Porphyromonas endodontalis.

Outer membrane proteins (OMP) of Porphyromonas endodontalis HG 370 (ATCC 35406) were prepared from the cell envelope fraction of the organisms. The cell envelope that had been obtained by sonication of the whole cells was extracted in 2% lithium dodecyl sulfate and then successively chromatographed with Sephacryl S-200 HR and DEAE-Sepharose Fast Flow. Two OMP fractions, OMP-I and OMP-II, were obtained, and their immunochemical properties and induction of specific antibodies were examined. The OMP-I preparation consisted of a major protein with an apparent molecular mass of 31 kDa and other moderate to minor proteins of 40.3, 51.4, 67, and 71.6 kDa, while the OMP-II preparation contained 14-, 15.5-, 27-, and 44-kDa proteins as revealed by sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis. OMP-I was found to form hydrophilic diffusion pores by incorporation into artificial liposomes composed of egg yolk phosphatidylcholine and dicetylphosphate, indicating that OMP-I exhibited significant porin activity. However, the liposomes containing heat-denatured OMP-I were scarcely active. Spontaneous and antigen-specific immunoglobulin M (IgM)-, IgG-, and IgA-secreting spot-forming cells (SFC) enzymatically dissociated into single-cell suspensions from chronically inflamed periapical tissues and were enumerated by enzyme-linked immunospot assay. In patients with radicular cysts or dental granulomas, the major isotype of spontaneous SFC was IgG. In radicular cysts, the OMP-II-specific IgG SFC represented 0.13% of the total IgG SFC, while the antigen-specific IgA or IgM SFC was not observed. It was also found that none of these mononuclear cells produced antibodies specific for OMP-I or lipopolysaccharide of P. endodontalis.

Antibodies, Bacterial↗
PubMed2003

The synergistic effect of peptidoglycan and lipopolysaccaride on osteoclast formation.

PURPOSE: The purpose of this study was to investigate the mechanisms leading to periapical tissue destruction by the Gram-positive bacterial cell component, peptidoglycan (PGN) and Gram-negative bacterial cell component lipopolysaccaride (LPS). STUDY DESIGN: Osteoclast precursor RAW 264.7 cells were cultured with 50 ng/ml receptor activator of NF-kappaB ligand (RANKL) for 72 hours. RANKL was then removed and the cells were treated with various concentrations of PGN in the presence or absence of various concentration of LPS for an additional 48 hours. RT-PCR analysis was performed to examine the presence of receptors on osteoclasts known to be involved in mediating cellular activation in response to PGN (TLR2) and LPS (TLR 4). RESULTS: PGN dose dependently and reproducibly stimulated TRAP-positive multinucleated osteoclast-like (OCL) cell formation. PGN and LPS had synergistic effects on the induction of OCL cell formation. Both unstimulated and RANKL-stimulated RAW 264.7 cells expressed TLR2 and TLR4 mRNA. CONCLUSION: The results underscore the importance of considering both Gram-positive and Gram-negative bacteria when interpreting findings associated with primary and secondary periapical lesions.

Acid Phosphatase↗
PubMed1999

Cell synthesis, proliferation and apoptosis in human dental periapical lesions analysed by in situ hybridisation and immunohistochemistry.

OBJECTIVE: The role of structural and host defensive cells in periapical lesions has been assessed previously by morphometric and immunohistochemical studies. The aim of this study was to investigate the function of peri- apical cells by employing molecular techniques to estimate the cell synthetic activity, proliferation and apoptosis in these lesions. We specifically sought answers to the following questions. Which cells of the periapical lesions are quiescent or actively synthesising proteins? Do immune cells proliferate in this region in the same way as epithelial cells proliferate? Furthermore do cells in peri- apical lesions undergo apoptosis, and if so which cells exhibit this programmed cell death? MATERIALS: Twenty-five periapical tissue samples (15 granulomas and 10 radicular cysts) were assessed. Poly-adenosine (poly (A)) RNA and ribosomal RNA (rRNA) bearing cells in formalin-fixed/paraffin-embedded peri- apical tissues were analysed by in situ hybridization (ISH) using digoxigenin-labelled oligo d (T) and 28S rRNA probes respectively in order to estimate cell synthetic activity. Furthermore, S-phase proliferating and cycling cells were examined by ISH using a histone probe and Ki-67 immunostaining so as to assess cellular proliferation. Mononuclear cells were further differentiated by immunohistochemistry (IHC) as T cells, B cells and macrophages. Apoptotic cells were determined by in situ end-labelling methodology for detecting fragmented DNA. RESULTS: Poly (A) RNA (mostly messenger RNA) and 28S rRNA-expressing cells were detected in all samples. Plasma cells exhibited strongest staining for the two probes, with slight to moderate staining found in the epithelium, fibroblasts, macrophages, endothelial cells and lymphocytes, whereas almost all polymorphonuclear leucocytes (PMN) were negative for these probes. A few histone mRNA-expressing cells were detected in basal and suprabasal epithelial cells and mononuclear cells in 15/25 cases but their reactivity was weak. Ki-67 positive cells were found in all samples and their numbers were generally higher than histone mRNA positive cells. Apo- ptotic cells were detected in 23/25 cases and the majority of apoptotic cells were PMN which were engulfed by large cytophagocytic macrophages. CONCLUSION: This study indicates that in dental periapical lesions, apoptosis occurs predominantly in PMN. It is evident that most cells apart from PMN are exhibiting synthetic activity but only epithelial cells undergo proliferation which implies that immune cells must proliferate at distant lymph nodes and travel to the periapical lesion rather than proliferating within the lesion. These results suggest considerable advantages in estimating gene expression within cells in addition to the immunohistochemical detection of cells to determine cell activity at inflamed sites. Clearly, functional cell synthetic activity, resolution and clearance systems operate in peri- apical cystic and granuloma lesions.

Adult↗
PubMed2006

Role of IL-2 and helper T-lymphocytes in limiting periapical pathosis.

The purpose of this study was to examine the role of IL-2 and helper T-lymphocytes in the development of periradicular lesions in rats. In control animals, periradicular lesions developed within 28 days following pulpal infection. Immunologically, some anti IL-2 and anti CD4-reactive helper T-lymphocytes infiltrated the periapical tissue at 14 days, and their numbers increased at 28 days. In experimental animals, tacrolimus (FK506) was injected every day to inhibit the IL-2 production by helper T-cells. Histologically, the pulpal necrosis and periradicular inflammation in tacrolimus-treated rats were more severe than those in the control rats. Furthermore, the areas of pulpal necrosis and periradicular lesion in the immunosuppressed rat were significantly greater than those in the normal ones. The numbers of IL-2- and CD4-positive cells in the lesion of the experimental rats were statistically lower than those of the control ones. These results show that the decrease in IL-2 might have promoted the development of periradicular lesions.

Alveolar Bone Loss↗
PubMed2006

Hospitalization of Western Australian children for oral health related conditions: a 5-8 year follow-up.

BACKGROUND: This study investigated in-patient oral health care provision for children under 18 years of age in Western Australia. METHODS: Hospitalizations of children for oral health conditions over a four-year period were analysed using data obtained from the Western Australian Hospital Morbidity Data System (HMDS). This study followed a previously published study examining similar data for 1995. RESULTS: Between 1999-2000 and 2002-2003, a total of 26 497 episodes of care were attributed to oral health conditions among children aged 0-17 years. The cost of this care exceeded $40 million. Embedded and impacted teeth accounted for 33.2 per cent of oral health episodes, dental caries 28.3 per cent, pulp and periapical tissue conditions 7.1 per cent and dentofacial anomalies 6.1 per cent. With the exception of the infant age group (0-1 years), non-Aboriginal children had higher admission rates than Aboriginal children. In the 13-17 year age group a non-Aboriginal child was 31 times more likely to be admitted to hospital for an oral condition than an Aboriginal child. CONCLUSIONS: This study confirms the impact of oral health related conditions among children in Western Australia. It is also clear that there are differences between age and population groups in terms of access to in-patient dental services and exposure to risk factors for specific oral conditions.

Adolescent↗
PubMed1998

Cytokine regulation on the synthesis of nitric oxide in vivo by chronically infected human polymorphonuclear leucocytes.

To determine if nitric oxide (NO) is produced by chronically infected human polymorphonuclear leucocytes (PMNs) in vivo, inflamed exudates (periapical exudates: PE) collected from periapical periodontitis patients were examined. Cell-free supernatants and cells were separated by centrifugation. Significant levels of nitrite concentrations were observed in the supernatants. The production of inducible NO synthase (iNOS) in highly purified PMNs derived from PEs was then immunocytochemically determined using rabbit anti-human iNOS antiserum. In vitro, human peripheral blood PMNs (PB-PMNs) isolated from patients were cultured with a combination of Esherichia coli-lipopolysaccharide (LPS), recombinant human interferon-gamma (rhIFN-gamma) and/or interleukin-1 beta (rhIL-1 beta). The stimulated PB-PMNs showed steady-state levels of nitrite. The stimulation of LPS, rhIFN-gamma and rhIL-1 beta showed more NO induction than that of LPS with either IFN-gamma or IL-1 beta, suggesting the synergistic effects of cytokines. Cryostat sections of surgically removed periapical tissues were also immunohistochemically examined for iNOS, IFN-gamma and IL-1 beta. Two-colour immunohistochemistry revealed the interaction of iNOS-producing PMNs and IFN-gamma- or IL-1 beta-producing mononuclear cells. On the basis of these data, we concluded that with the stimulation of inflammatory cytokines derived from mononuclear cells, PMNs can spontaneously produce NO at the site of chronic infection. The present studies are consistent with a hypothesis suggesting that PMNs could be regulated and delicately balanced to produce NO by mononuclear cell-derived cytokines in vivo. NO-producing cells may play a pivotal role in chronic inflammation.

Adult↗
PubMed2002

Discuss that the coronal seal is more important than the apical seal for endodontic success.

One of the main principles for successful root canal treatment is the prevention of microorganisms and toxins from the oral flora penetrating through the root canal system into the periapical tissues (1). This is achieved by obturating the root canal system completely, including the coronal and apical ends. Inadequate obturation of the root canal system has been found to be the most frequent cause of failure after endodontic treatment (2). A number of studies have indicated that leakage, whether from a coronal or apical direction, adversely affects the success of root canal treatment (3-7). The significance of the coronal seal has been increasingly recognized in the dental literature (4, 5, 8, 9) and in more recent times, it has been suggested that apical leakage may not be the most important factor leading to the failure of endodontic treatment--but that coronal leakage is far more likely to be the major determinant of clinical success or failure (10). This paper will discuss aspects of: endodontic success and failure; the use of leakage studies to assess the quality of the seal; the significance of both apical and coronal leakage; followed by a review of the literature.

Dental Bonding↗
PubMed1988

Periapical innervation of the ferret canine and the local retrograde neural changes after pulpectomy.

The amputation of the dental pulp severs a population of axons that are predominantly in the A delta and C fiber size range and are principally involved in nociception. Local periapical neuromas, if they are formed after pulpectomy, may be the sites of spontaneous nervous activity that may, in some circumstances, be involved in the genesis of chronic pain. The periapical tissues from the mandibular canines of four ferrets were examined 3 months after pulpectomies. Silver-stained paraffin sections were examined in three dimensions at the light microscope level. Ultrathin sections were examined at the electron microscope level. Compared with contralateral and independent controls, the principal changes were the loss of the periodontal plexus around the root apex, the extension of damage well below the apical foramen, and the persistence of inflammation 12 weeks postoperatively. While a somewhat disorderly mass of nerve fibers develops subapically, the arrangement has only some of the features usually associated with neuromas.

Animals↗
PubMed1984

The central projections of tooth pulp afferent neurons in the rat as determined by the transganglionic transport of horseradish peroxidase.

Transganglionic transport of horseradish peroxidase (HRP) or horseradish peroxidase-wheat germ agglutinin conjugate (HRP-WGA) was used to map in detail the central projections of trigeminal primary afferent neurons that innervate the dental pulp organ of the rat. In each of ten animals, 0.5-2.0 microliters of enzyme solution was injected into the pulp chamber of the first maxillary molar tooth. Postmortem examination of the decalcified teeth in all cases showed that the HRP/HRP-WGA remained confined to the pulp chamber and pulp roots, with no spread of enzyme into periapical tissues. HRP-labeled tooth pulp afferent fibers projected to all four rostrocaudal subdivisions of the ipsilateral trigeminal brainstem nuclear complex (TBNC) and to the upper cervical spinal cord. The labeled terminal fields formed a column that stretched relatively uninterrupted from just caudal to the rostromedial tip of the trigeminal principal sensory nucleus to at least the C2 segment of the spinal cord. The density of the afferent projection varied markedly from one rostrocaudal level of the TBNC to the next but was heaviest in an area encompassing the caudal one-half of the principal sensory nucleus and the rostral two-thirds of pars oralis. Fibers projected only lightly to pars caudalis, where they terminated preferentially in laminae I, IIa, and the junctional zone between laminae IV and V. HRP-labeled terminals in C1 and C2 were located almost exclusively in laminae I. In the dorsoventral axis, the terminal fields in the TBNC were located in a surprisingly dorsal part of the complex, well within what has been shown by others to be largely an area of termination for mandibular division fibers. Most fibers ended in medial parts of the TBNC, with the exception of two modestly labeled terminal fields located in the lateral aspects of rostral pars oralis and rostral pars caudalis. No labeled fibers terminated in the contralateral TBNC or contralateral cervical spinal cord.

Animals↗
PubMed2004

Analgesic use in dentistry in a tertiary hospital in western Nepal.

The present study had been planned to determine the pattern of drug utilization of analgesics (non-opioid and opioid analgesics) in dental outpatients in a referral hospital in western Nepal. A total of 1820 prescriptions of dental patients attending the dental outpatient at Manipal Teaching Hospital (MTH), Fulbari, Pokhara, Nepal were collected by a random once-weekly survey between March 2001 and February 2002. The analgesic-containing prescriptions (n = 1346) were separated from the total prescriptions collected. This information was compiled, scored and analyzed in consultation with dentists using WHO guidelines. There were more female patients (56%) than male patients (44%) in this study. The dental disorders most frequently reported in our study were diseases of pulp and periapical tissue (36.5%), gingivitis and periodontal diseases (28.5%) and dental caries (16%) etc. In total, 74% prescriptions contained analgesics which are the second-most commonly prescribed drugs after anti-microbials (44.9%) in dental OPD. The total analgesics prescribed were 1358 that account for 36.7% of total drugs prescribed. Only 5 and 37.8% of analgesics were prescribed generically and from the essential drug list of WHO respectively. All the analgesics were administered orally which included 89.7 and 10.3% of non-opioid analgesics and opioid analgesics (propoxyphene and dextropopoxyphene) respectively. The average duration of analgesic use was 3.5 +/- 0.3 days. The most commonly prescribed non-opioid analgesic was ibuprofen (41%) followed by nimesulide (22%). A total of 38.9% analgesics were fixed-dose combinations (FDCs) of two drugs and the most common analgesic combination used was ibuprofen + paracetamol and paracetamol + opioid analgesics. All opioid analgesics were prescribed in combination with paracetamol (10.3%) only. In total, 1.6% analgesics were prescribed concomitantly with gastroprotective agents. All gastroprotective agents (n = 22) were prescribed concomitantly with opioid analgesics only. No gastroprotective was used when NSAIDs were prescribed alone or in combination with paracetamol. Our present study indicate that all the analgesics were prescribed in oral dosage forms but analgesics prescribed in generic name (5%) and from essential drug lists (37.8%) were very less. There was an inclination to prescribe the older non-opioid analgesics. Selection of analgesics was quite rational in our study but some lacunae were observed. A total of 38.9% analgesics were FDCs and most common FDC analgesics were ibuprofen + paracetamol. Avoiding unnecessary FDCs may help in reducing prescribing costs because FDCs usually cost more than single ingredient preparations. It is best to avoid combination therapy with more than one non-opioid analgesic; there is little evidence of extra benefit to the patient and the incidence of side effects generally is additive. Prescribing generic names aids in avoiding confusion and minimizing the costs. In the present study, coprescription of gastroprotective agents with analgesic use was low compared to a previous study but when opioid analgesics were prescribed, concurrent use of gastroprotective agents were irrational as opioid analgesics usually decrease the secretion of hydrochloric acid. It is also surprizing that, no gastroprotective was used when NSAIDs were prescribed alone, irrespective of sex, age, dose or duration or type of NSAID treatment in our study. There is a clear need for the development of prescribing guidelines and educational initiatives to encourage the rational and appropriate use of analgesics in dentistry.

Adolescent↗
PubMed1976

Endodontics and the irradiated patient.

With increasingly larger numbers of irradiated patients in our population, it seems likely that all denists will eventually be called upon to manage the difficult problems that these patients present. Of otmost concern should be the patient's home care program and the avoidance of osteroradionecrosis. Endodontics and periodontics are the primary areas for preventing or eliminating the infection that threatens osteoradionecrosis. Endodontic treatment must be accomplished with the utmost care and maximum regard for the fragility of the periapical tissues. Pulpally involved teeth should never be left open in an irradiated patient, and extreme care must be taken with the between-visits seal. If one is called upon for preradiation evaluation, routine removal of all molar as well as other compromised teeth should be considered. Attention should be directed to the literature for further advances in the management of irradiated patients.

Dental Caries↗
PubMed1977

Electronic ohmmeter. An electronic device for the determination of the root canal length.

The electronic ohmmeter was devised for the accurate determination of root canal length. Fifty-one maxillary anterior teeth of 43 patients and 25 posterior root canals from 10 patients were selected for the investigation. The presence of a lesion in periapical tissue, wide root apex, and exudates in the root canal contributed to inaccuracy in the determination of the root canal length. Correct length can be found if precautions are taken. The inaccurate results were corrected by repeating the procedures and taking precautions during the estimation of root canal length. Measurement in the dry canal gave correct estimation of the root canal length. When distilled water or normal saline was used as conducting medium in root canals, accuracy was not as good as in dry canals. The electronic ohmmeter is a useful and economical device and an endodontic aid for determination of the root canal length.

Adolescent↗
PubMed1989

Dens invaginatus of a maxillary lateral incisor: endodontic treatment.

A right maxillary central incisor and an adjacent lateral incisor with a dens invaginatus were identified as requiring endodontic treatment. Both teeth were treated by nonsurgical means. Thirteen months postoperatively the central incisor showed evidence of periapical resolution, whereas the lateral incisor did not. The lateral incisor was then treated with apical curettage, an apicoectomy, and retrograde amalgam filling. One year after the surgical procedure the periapical tissues of both the lateral and central incisors exhibited satisfactory resolution. This case demonstrates that certain cases of dens invaginatus can be successfully treated only with a surgical approach.

Adult↗
PubMed1994

Histologic effects of a thermally cooled Nd: YAG laser on the dental pulp and supporting structures of rabbit teeth.

The histologic response of the pulp, periapical tissues, supporting periodontal ligament, and alveolar bone adjacent to the incisor teeth of adult rabbits was compared after laser treatment (etching) or drilling with a high-speed dental rotary handpiece (enamelplasty) on the buccal enamel surface. Observations were made at four time periods, 2 days, 14 days, 60 days, and 180 days after treatment. Block sections were removed, and serial sections were prepared and examined by an independent veterinary pathologist for occurrences of histopathologic changes with untreated control teeth used for comparison. Under the conditions of this study, there were no differences between either the laser-treated or the drilled specimens compared with the untreated control teeth on the basis of the histologic appearance.

Animals↗
PubMed2004

Spatial distribution of lead in the roots of human primary teeth.

Lead remains one of the most hazardous metals in our environment. The concentrations of lead in coronal dentine and enamel have previously been reported but limited information is available regarding lead levels in radicular dentine and cementum. This study reports the distribution of lead in 26 roots of 16 human maxillary primary teeth from seven individuals. In addition, calcium and phosphorous concentrations were also measured to detect any variations in the degree of mineralization in different regions of the roots. The mean lead concentration in these roots was 1.67 +/- 1.43 microg/g, which is comparable to other studies. In all cases there were higher lead concentrations in the apices of non-resorbed roots of primary maxillary teeth relative to middle and cervical regions. The findings reported here are of potential significance during the process of physiological root resorption whence periapical tissue may be exposed to higher levels of lead.

Calcium↗