Identification of cellulose fibers in oral biopsies

Oral biopsies comprising five periapical cysts, three cases of exuberant granulation tissue in extraction sockets and one case of a mandibular radiopaque structure, all displaying material consistent with cellulose fibers on routine histologic examination, were subjected to histochemical, polarization, fluorescence and scanning electron microscopical, energy dispersive X-ray and chemical investigations. Routine screening of periapical lesions with polarization microscopy and identification of possible cellulose fibers with Calcofluor White is advocated. Further, attention is drawn to endodontic paper point material as an etiologic factor in postendodontic periapical inflammatory processes.     

Accidental swallowing of an endodontic file

Aim  To report the management of an iatrogenic incident in which an endodontic file was swallowed accidentally and passed into the gastrointestinal tract.
Summary  A 51-year-old male swallowed a 21 mm, size 30 endodontic file during root canal treatment without rubber dam. In the absence of clinical complications, the patient was reviewed with serial chest and abdominal radiographs, and stool tests for occult blood until the instrument was discharged at 3 days. This report discusses early differential diagnosis for locating foreign bodies and underlines the importance of serial radiographic evaluation for signs of foreign body migration.
Key learning points • The use of rubber dam is mandatory for patient safety during root canal treatment.
• Early location of an inhaled or ingested foreign body facilitates appropriate and timely treatment management and referral.
• When a foreign body passes into the gastrointestinal tract, clinical symptoms and signs should be monitored closely until it is excreted or removed.
• An endodontic file can pass through the gastrointestinal tract asymptomatically and apparently atraumatically within 3 days.     

Commentary: The Case for Routine Maintenance of Dental Implants

The large majority of dental implants are successful over the long term. Failure is usually associated with infection, trauma, inflammation, or a combination of these factors. Early identification and appropriate treatment can identify and eliminate these problems in the majority of cases. Thus routine implant maintenance structured along the guidelines for patients with periodontal diseases is recommended.     

Effect of eugenol on macrophage adhesion in vitro to plastic surfaces

Abstract— This study was performed to investigate the in vitro effect of eugenol on substrate adherence capacity of macrophages. hlacro-phages were obtained from Wistar rats. The adherence capacity of macrophages to the plastic surface of Eppendorf tubes was determined. Assays were canied out in these tubes for 15 min of incubation at 37°C in a humidified atmosphere of 5% CO₂ in air. Control peritoneal macrophages showed an adherence index=52.5%. Eugenol decreased the adherence index of macrophages in a dose-dependent manner. A 1:1000 dilution of eugenol decreased the adherence index of macrophages by 16.6% (P<0.05). Lower dilutions (1:100 and 1:10) greatly decreased the adherence index by 51% and 96.2% respectively (P<0.01). Taking into account that substrate adherence is the first step in the phagocytic process of macrophages and in antigen presentation, eugenol could inhibit macrophage function and modulate immune and inflammatory reactions in dental pulp and periapical tissues.     

Endodontic complications in teeth with vital pulps restored with composite resins: a systematic review

Composite resin is used extensively for restoration of teeth with vital pulps. Although cell culture studies have disclosed harmful effects on pulpal cells, any untoward clinical effects, manifest as adverse pulpal responses, have yet to be determined. This study comprises a systematic review, designed to address the question of whether the risk of endodontic complications is greater with composite resin restorations than with other restorative materials, such as amalgam. The study methodology involved (i) formulation of the research question, (ii) construction and conduct of an extensive literature search with (iii) interpretation and assessment of the retrieved literature. A search of the medical database PubMed was complemented with a search of the Controlled Trials Register (CENTRAL). The initial search yielded 1043 publications, the abstracts of which were read independently by the authors. After additional searches, 10 studies were included in the review. In all the included studies, the level of evidence was assessed as low. No conclusions could therefore be drawn. The included studies reported few, if any, endodontic complications. Little or no differences emerged between teeth restored with composite resins and those restored with amalgam. To determine whether composite resin restorations of teeth with vital pulps are associated with an increased risk for development of endodontic complications such as apical periodontitis, further evidence is needed, from well‐constructed studies with a large number of participants.     

Direct amplification of rRNA gene sequences for identification of selected oral pathogens in root canal infections

Aim The purpose of this study was to assess the prevalence of selected oral pathogens in root canal infections and their relationship with symptoms using a highly sensitive technique, the polymerase chain reaction. Methodology Samples were obtained from 91 infected teeth associated with periradicular lesions, including cases of acute periradicular abscesses. DNA was extracted from the samples and analysed for the presence of target microbial species using a PCR‐based identification assay. Results All samples were positive for the presence of bacteria. Streptococcus anginosus group was detected in 16.7%, Fusobacterium nucleatum in 14.3%, and Bacteroides forsythus in 7.1% of the abscess samples. No pus sample yielded Actinomyces israelii, Actinobacillus actinomycetemcomitans or fungal species. In general, B. forsythus was found in 20% of the cases (16 of 80), S. anginosus in 12% (6 of 50), F. nucleatum in 10% (6 of 60) and A. israelii in 5% (two of 40). A. actinomycetemcomitans was not detected in any case. Fungi were present in only one of 50 cases (2%). There was no correlation between the species and symptoms. Conclusions Direct molecular approaches appear to be a valuable tool for the rapid and reliable diagnosis of infectious diseases, as well as for research purposes. There was no correlation between target microbial species and symptoms.     

Clinical performance of three endodontic sealers

Abstract The clinical performance of three endodontic sealers, AH 26®, Kloroperka N-Ø® and ProcoSol®, was assessed in a prospective study of endodontic treatment in 810 roots. The roots were treated by undergraduate students according to a standardized procedure, and were filled with laterally condensed gutta-percha and sealer. The sealer was randomly selected just prior to filling. The patients were recalled yearly for 4 years for a clinical and radiographic control examination, and the radiographs were scored using the periapical index (PAI) scoring system. Ridit analysis provided optimal discrimination between subgroups of roots with regard to the radiographic status of the periapical tissues as a measure of the clinical performance of the materials. The periapical status of roots filled with AH 26® or ProcoSol® was better than that of roots filled with Kloroperka®. The difference was significant after 1 year and persisted through the 4-year observation period. The difference was also evident after stratification of the material with regard to preoperative pulpal and periapical diagnoses. It is concluded that the choice of sealer may influence the outcome of endodontic treatment, and that the perapical index is a useful discriminatory tool for assessment of treatment results in endodontics.     

Measurements of currents between dissimilar alloys in the oral cavity

abstract – A method is described for the measurement of currents generated between dissimilar alloys in the oral cavity. Tests were performed using amalgam fillings versus specimens consisting of a gold alloy, a chromium-cobalt alloy and a stainless steel alloy. Currents of 0.1–0.3 μA/cm² of specimen area were measured.     

Effects of root canal sealers on immunocompetent cells in vitro and in vivo

Over the years of testing biocompatibility of endodontic filling materials, little attention has been paid to the potential adverse influences on the function of the immune system. Therefore, the purpose of this study was to investigate the extent to which extractable components of some commonly used root canal sealing materials (ERCS) may interfere with immunocompetent cells in vitro. The potential of these materials to cause delayed-type hypersensitivity (DTH) was also addressed in a rat model system. Extractable components were drawn in cell culture medium from freshly mixed or set material of AH 26. Grossman's sealer, Endomethasone, and Apexit. In-vitro assays included either spleen cells or rat pulp tissue cells that were released following enzymatic digestion with collagenase. Purified T cells for the pulpal cell assay were obtained from rat mesenteric lymph nodes. The effect of ERCS on the proliferation of concanavalin A (con A) stimulated spleen cell was measured by 3H-thymidine incorporation. Pulpal accessory cell function was monitored by the capacity of pulpal cells, pretreated with components of ERCS, to provide signals to con A stimulated T cells. DTH was tested after subcutaneous implantation of root canal sealers (RCS) in rats and challenge by ear injection. Pretreatment of pulpal cells with low dilutions of eluates from extracted AH 26 and Endomethasone resulted in a strong reduction of the T cell proliferation rate. The effect was considerably reduced (P < 0.01) when extracts of the solid material were employed. Extracts of Grossmans' sealer and Apexit affected T cell proliferation only to a limited extent in the pulpal cell assay. In general, assays on spleen cells showed a similar profile, although increased cell division was induced by Grossman's sealer at high eluate dilutions and a concentration-dependent decrease of cell division at lower concentrations of this material. ERCS evoked both immunosuppression and, in some instances, immunostimulation, but they did not release DTH.     

Long-term retention of a paper point in the periapical tissues: a case report

Abstract A case is reported of a 15 mm paper point found in the periapical area of a maxillary right central incisor during endodontic surgery for an unresolved periapical radiolucency. The paper point had been present for between live and nine years. Histopathological examination showed the presence of chronically inflamed fibrous connective tissue with a number of foreign body giant cells and focal collections of chronic inflammatory cells. SEM comparison of the specimen with a similarly treated fresh paper point showed no indication of degradation of the paper point by host defense cells.     

口腔门诊治疗中1429例患者应用笑气镇静技术的回顾性分析

目的 回顾性分析笑气镇静技术在口腔门诊中的使用情况及效果.方法 对2016年1月1日至2018年12月30日期间在广州医科大学附属口腔医院门诊使用笑气吸入镇静治疗的1429个病例进行如下分析:病例的人群分布、牙科治疗项目、使用笑气吸入的原因、不同年龄段患者的镇静效果和不良反应.结果1429例患者中,男性587例,女性8...     

Biocompatibility of various dental materials in contemporary dentistry: a narrative insight

In the past few decades, there has been an increase in demand for safety evaluation and control of dental materials used daily in dentistry; however, this task is difficult and cumbersome. Dental materials that are passive and do not react with the oral environment will be more stable and have superior durability. It is expected that dental materials will be universally accepted and will not cause harm or injury to the surrounding structures in the oral cavity. This is an entirely negative approach to the material tolerance and biocompatibility, and hides the possibility that some positive gains can be achieved. Side‐effects of dental materials are believed to be rare, and generally, those that have been reported are mild. There are wide varieties of materials used in dentistry, which include liners, irrigants, intracanal filling materials, intracanal medicaments, prosthetic materials, restorative materials, subgingival implants, and mouth rinses. Therefore, in this study, the biocompatibility of various commonly‐used clinical materials used in contemporary dentistry was discussed.     

Immunogenic potential of some mercury compounds in experimental contact allergy of the rat oral mucosa

Abstract — The contact allergenic potential of substances included in a "dental screening test" has been investigated in a previously established animal model for producing contact allergy. We were unable to produce contact hypersensitivity with any of the original formulas. HgCl₂ was selected for further studies and, in order to improve its penetration, butanol was used as a solvent. Sensitization was, however, not obtained with any of the HgCl₂/butanol formulas. Our results are discussed in relation to the requirements of reaching immunogenic threshold levels of mercury in the tissue.     

Occurrence of two newly named oral treponemes - Treponema parvum and Treponema putidum - in primary endodontic infections

Background/aims:  Recent evidence from molecular genetic studies has revealed that oral Treponema species are involved in infections of endodontic origin. This study assessed the occurrence of two newly named oral treponemes −  Treponema parvum and Treponema putidum –  in primary endodontic infections using a culture-independent identification technique.
Methods:  Genomic DNA was isolated directly from clinical samples, and a 16S rRNA gene-based nested polymerase chain reaction (PCR) assay was used to determine the presence of T. parvum and T. putidum . Species-specific primer pairs were developed by aligning closely related 16S rRNA gene sequences. The specificity for each primer pair was validated by running PCR against a panel of oral bacteria and by sequence analysis of PCR products from positive clinical samples.
Results:  T. parvum was detected in 52% of the root canals associated with chronic apical periodontitis, in 20% of the cases diagnosed as acute apical periodontitis, and in no abscessed case. In general, T. parvum was detected in 26% of the samples from primary endodontic infections. T. putidum was found in only one case of acute apical periodontitis (2% of the total number of cases investigated).
Conclusions:  The devised nested PCR protocol was able to identify both T. parvum and T. putidum directly in clinical samples and demonstrated that these two treponemes can take part in endodontic infections.     

The oral mucosa as a mirror of general health or disease

There is a close relationship between general health/disease and oral mucosal reactions. Many diseases show unspecific or specific changes which may evolve throughout the course of the disease but the mucosal reaction may also constitute the initial clinical sign of the disease. Among the broad spectrum of conditions/diseases, three have been selected for this review - HIV/AIDS, Sjögren's syndrome and lichen planus. They illustrate how general disease may be mirrored in the oral mucosa. An attempt has been made to describe the scientific frontiers and to select pertinent key or review articles or books from among the huge amount of literature published in recent years.     

音乐疗法在口腔领域中的应用

音乐治疗以心理治疗的理论和方法为基础,运用音乐特有的生理、心理效应,使患者通过各种专门设计的音乐行为,经历音乐体验,达到消除心理障碍,恢复或增进心身健康的目的.随着各学科交叉渗透的增多,音乐治疗已经成为现代医学心理－社会－生物治疗模式中的重要方法之一.本文就近年来音乐疗法在口腔领域各亚学科,如牙体牙髓病科、颌面外科、正...     

A simple model for evaluating relative toxicity of root filling materials in cultures of human oral fibroblasts

Abstract Standardized test tubes filled with freshly mixed root filling materials (AH26, CRCS, N2, Kloroperka NØ, ZOE cement and 2 experimental cements, ECI and ECII) were transferred into tissue culture flasks. Normal human oral fibroblasts were seeded in the flasks. Morphological cell changes were studied up to 15 days after seeding. The size of cell-free zones around the test tubes and the total cell number per culture flask were calculated after 5, 10 and 15 days. The findings showed N2 cement to be by far the most toxic material at all observation periods, whereas no toxic reactions could be seen in relation to tubes filled with Kloroperka NØ. Compared with the 5-clay observation period, some cell recovery was observed around test tubes with AH26 and ECII, whereas almost full cell recovery was found around test tubes with CRCS, ZOE and ECI. It was concluded that the present model, which allows long-term observations of human cellular reactions to dental materials, can be used as a simple and relatively cheap screening test for initial toxicity testing of dental materials.