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Papers by Pia Sunde

Clinical Oral Investigations, Jul 11, 2023

Objectives This study aimed to identify disease-related markers in persistent apical periodontiti... more Objectives This study aimed to identify disease-related markers in persistent apical periodontitis (PAP) biopsies and examine whether these were associated with comorbidities like rheumatoid arthritis (RA) and cardiovascular diseases (CVD). Materials and method The levels of the cytokines/chemokines GM-CSF,

Research Square (Research Square), Sep 22, 2022

, MIP-3α/CCL20 and TNF-α were determined in lesions from patients with persistent apical periodon... more , MIP-3α/CCL20 and TNF-α were determined in lesions from patients with persistent apical periodontitis (n = 20) and compared to healthy bone samples (n = 20). Results: We identi ed eleven cytokines to be differently expressed, and among them, IL-2, IL-6, IL-17E, IL-21, and IL-27 appeared to drive the discrepancy between the disease and healthy groups. The levels of T follicular helper (Tfh) cell promoting cytokines (IL-21, IL-6, IL-27) were enhanced while T helper (Th) 1 cell promoting cytokine (IL-2), Th2 cell promoting cytokine (IL-13), and Th17 cell promoting cytokine (IL-17E) were reduced in the PAP group. The data also indicate that Tfh cell differentiation (IL-21), along with Th1 (GM-CSF, IFNγ), Th2 (IL-13), and Th17 (GM-CSF) cell differentiation, might be increased in the subpopulation of patients suffering from rheumatoid arthritis, whereas no differences were found in patients with cardiovascular diseases. Conclusions: A cluster of potential cellular markers for PAP was identi ed. The lesions contained additional factors that might be associated with differentiation of various T cell populations. Clinical Relevance: Molecular analyses of PAP may result in identi cation of prognostic markers. Introduction: Root canal infection results in breakdown of the periapical bone and formation of an apical lesion which is manifested on X-ray by the formation of a periapical radiolucency. An apical lesion is a mass of in amed granulation tissue surrounded by an outer capsule of dense brous tissue [1]. Granulation tissue contains a variety of cells including immune cells such as lymphocytes (T cells and B cells). At dental educational institutions and in specialist practice, a success rate of endodontic treatment of 75-85% is shown in teeth with preoperative apical periodontitis (AP) [2-6]. Persistent apical periodontitis (PAP) is a chronic in ammatory disease that occurs when root canal treatment has not adequately eliminated the infection. PAP can be asymptomatic or symptomatic and is most often diagnosed by observing visible lesions on X-ray. Teeth with PAP can be treated by either nonsurgical endodontic retreatment or periapical surgery. Large apical lesions (> 5 mm) have showed lowered healing rate compared to smaller lesions (< 5 mm) [5, 7] and teeth with lesions > 5mm are more likely to be extracted [8]. Large lesions are also correlated with development of cysts [9]. The reduction of periapical bone, caused by an imbalance between osteoblast and osteoclast activity, may be modulated by cytokines [10]. Cytokines are signaling molecules that most cells produce in ±

Tissue Engineering Part B-reviews, May 23, 2023

International Endodontic Journal, May 1, 2020

Case reports can provide early information about new, unusual or rare disease(s), newer treatment... more Case reports can provide early information about new, unusual or rare disease(s), newer treatment strategies, improved therapeutic benefits and adverse effects of interventions or medications. This paper describes the process that led to the development of the Preferred Reporting Items for Case reports in Endodontics (PRICE) 2020 guidelines through a consensus-based methodology. A steering committee was formed with eight members (PD, VN, BC, PM, PS, EP, JJ and SP), including the project leaders (PD, VN). The steering committee developed an initial checklist by combining and modifying the items from the Case Report (CARE) guidelines and Clinical and Laboratory Images in Publications (CLIP) principles. A PRICE Delphi Group (PDG) and PRICE Face-to-Face Meeting Group (PFMG) were then formed. The members of the PDG were invited to participate in an online Delphi process to achieve consensus on the wording and utility of the checklist items and the accompanying flow chart that was created to complement the PRICE 2020 guidelines. The revised PRICE checklist and flow chart developed by the online Delphi process was discussed by the PFMG at a meeting held during the 19th European Society of Endodontology (ESE) Biennial Congress in Vienna, Austria, in September 2019. Following the meeting, the steering committee created a final version of the guidelines, which were piloted by several authors during the writing of a case report. In order to help improve the clarity, completeness and quality of case reports in Endodontics, we encourage authors to use the PRICE 2020 guidelines.

Objectives: This study aimed to identify disease-related markers in persistent apical periodontit... more Objectives: This study aimed to identify disease-related markers in persistent apical periodontitis (PAP) biopsies and examine whether these were associated with comorbidities. Materials and method: The levels of the cytokines GM-CSF, IFN-γ, IL-2, IL-6, IL-9, IL-10, IL-13, IL-15, IL-17E/IL-25, IL-21, IL-23, IL-27, IL-28A/IFN -λ2, IL-33, MIP-3α/CCL20 and TNF-α were determined in lesions from patients with persistent apical periodontitis (n = 20) and compared to healthy bone samples (n = 20). Results: We identified eleven cytokines to be differently expressed, and among them, IL-2, IL-6, IL-17E, IL-21, and IL-27 appeared to drive the discrepancy between the disease and healthy groups. The levels of T follicular helper (Tfh) cell promoting cytokines (IL-21, IL-6, IL-27) were enhanced while T helper (Th) 1 cell promoting cytokine (IL-2), Th2 cell promoting cytokine (IL-13), and Th17 cell promoting cytokine (IL-17E) were reduced in the PAP group. The data also indicate that Tfh cell diff...

Den norske tannlegeforenings Tidende, Apr 16, 2020

Kasuistikk • Ortograd rotfyllings te ra pi av unge ten ner med dens invaginatus: To ka sus Ortogr... more Kasuistikk • Ortograd rotfyllings te ra pi av unge ten ner med dens invaginatus: To ka sus Ortograd rotfyllings te ra pi av unge ten ner med dens invaginatus: To ka sus Line Rør slett Har der sen, Mar ga reth Kris ten sen Ot ter sen og Pia Tit te rud Sunde FORFATTERE Line Rørslett Hardersen, spesialist i endodonti, Avdeling for endodonti, Institutt for klinisk odontologi, Universitetet i Oslo. Margareth Kristensen Ottersen, spesialist i kjeve-og ansiktsradiologi, stipendiat. Avdeling for kjeve-og ansiktsradiologi, Institutt for klinisk odontologi, Universitetet i Oslo.

Clinical Oral Investigations, Aug 5, 2022

Dental Materials, Jun 1, 2022

European Journal of Oral Sciences, Jun 30, 2023

This study investigated the role of aging and changes in environmental conditions on selected pro... more This study investigated the role of aging and changes in environmental conditions on selected properties of a prototype radiopacified calcium silicate‐based cement (TZ‐base) with or without incorporation of silver nanoparticles or bioactive glass, and two commercial materials, Biodentine and intermediate restorative material. Materials were immersed in ultrapure water or fetal bovine serum for 28 days and were characterized with scanning electron microscopy and energy dispersive x‐ray analysis. Immersion media were either replaced weekly or not replenished at all and were assessed for alkalinity and calcium release after 1, 7, 14, 21, and 28 days; antibacterial effect against 2‐day monospecies biofilms; and cytotoxicity by the 3‐(4,5 dimethylthiazolyl‐2‐yl)‐2,5‐diphenyl tetrazolium bromide assay after 1, 7, or 28 days. Alkalinity, calcium release, antibacterial activity, and cell cytotoxicity increased over time when the medium was not changed but decreased with medium replenishment. Immersion in fetal bovine serum resulted in lower alkalinity, less bactericidal properties, and lower cytotoxicity of prototype cements and Biodentine than did water immersion. Biodentine and 20% bioactive glass‐containing cement had overall lower alkalinity, calcium release, and antibacterial activity than TZ‐base, and Biodentine was less cytotoxic than TZ‐base. In conclusion, exposure conditions and cement modifications significantly affected materials’ leaching properties. Exposure conditions warrant consideration when evaluating cements’ clinical properties.

Acta Odontologica Scandinavica, May 16, 2019

Journal of Functional Biomaterials, Oct 10, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

International Endodontic Journal, Dec 7, 2021

This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Acta Odontologica Scandinavica, Jan 27, 2021

Abstract Objective To evaluate the knowledge and insights of general dental practitioners regardi... more Abstract Objective To evaluate the knowledge and insights of general dental practitioners regarding endodontic diagnosis and treatment principles before and after attending a 2-days continuing education course. Materials and methods Sixty-seven dentists employed in the Public Dental Service in Møre and Romsdal county, Norway, were invited to a continuing education course in endodontics. Before and after the course, they answered a questionnaire weighing the importance of factors influencing the prognosis of endodontic treatment. The same questionnaire was answered by specialists in endodontics (n = 56; Spec Group) and a reference group consisting of general dental practitioners from both private and public practice (n = 21; Ref Group). The Test Group answered both before and after the course, while the Spec and Ref Groups completed the questionnaire once. The responses were compared using the Wilcoxon Sign test and Mann–Whitey U test. Results Of the 67 dentists in the Test Group, 49 (73%) completed the course and answered both questionnaires. Before attending the course, the Test Group differed significantly from the Spec Group in 18 out of 27 prognostic factors (p ≤ .05). After the course, there was only moderate improvement in the Test Group responses. On only three factors, they agreed significantly more with the specialists than before attending the course (p ≤ .05). After the Test Group participants had attended the course, their responses were comparable to the responses of the Ref Group. Conclusions A two-days continuing education course only marginally improved dentists’ level of knowledge and insights regarding the influence of prognostic factors in endodontics.

Journal of Endodontics, Apr 1, 2002

The periapical microbiota of 36 teeth with refractory apical periodontitis was investigated. None... more The periapical microbiota of 36 teeth with refractory apical periodontitis was investigated. None of the teeth had responded to conventional endodontic or long-term (> 6 months), calcium-hydroxide treatment. Eight patients had received antibiotics systemically. After anaerobic culture, a total of 148 microbial strains were detected among 67 microbial species. One of the 36 lesions was culturenegative. Approximately half (51.0%) of the bacterial strains were anaerobic. Gram-positive species constituted 79.5% of the flora. Facultative organisms, such as Staphylococcus, Enterococcus, Enterobacter, Pseudomonas, Stenotrophomonas, Sphingomonas, Bacillus, or Candida species were recovered from 27 of the lesions (75%). Sulfur granules were found in 9 lesions (25%). In these granules Actinomyces israelii, A. viscosus, A. naeslundii, and A. meyeri were identified. Other bacterial species, both Gram-positive and Gramnegative, were detected in the granules as well. Two sulfur granules did not contain Actinomyces. Scanning electron microscopy demonstrated rodand spirochete-like cells in the granules, and transmission electron microscopy revealed organisms with copious amounts of extracellular material. Outer membrane vesicles were also seen. Some of the granules were calcified. This study demonstrated a wide variety of microorganisms, particularly Gram-positive ones, in the periapical lesions of teeth with refractory apical periodontitis.

Journal of Medical Virology, 2008

Periodontitis is presumably caused by bacterial infection, but it has been shown recently that af... more Periodontitis is presumably caused by bacterial infection, but it has been shown recently that affected tissue often contains human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV). The present study was initiated to evaluate the role of these viruses in the pathogenesis of periodontitis. HCMV and EBV were quantified in 40 apical and 25 marginal periodontitis samples using real time PCR. In situ hybridization or immunohistochemistry was carried out on apical samples to detect viral presence within cells. A possible association with relevant bacteria was examined. Of the apical periodontitis samples, 50% contained EBV, while none contained HCMV. Of the marginal periodontitis samples, 40% were positive for EBV and 12% for HCMV. With one exception, however, the amount of virus was close to the detection limits. EBV was only detected in 1 out of 15 healthy periodontium samples. Immunohistochemistry and in situ hybridization were all negative. Significant associations were found between periodontal EBV and the presence of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. Although there was an obvious association of the virus with clinical samples, it seems unlikely that these viruses play a major role in the pathogenesis of periodontitis of the average patient. Their presence may reflect that the clinical samples contain more blood or saliva compared to controls, or an accumulation of lymphoid cells harboring virus in the inflamed tissue.

Journal of Endodontics, 2018

Introduction: The aim of this study was to investigate the antibacterial activity of 4 endodontic... more Introduction: The aim of this study was to investigate the antibacterial activity of 4 endodontic sealers against bacteria planktonic grown or in biofilms commonly detected from persistent and secondary endodontic infections. Methods: The antibacterial activity of the sealers AH Plus, TotalFill BC sealer, RoekoSeal, and Guttaflow 2 was investigated for planktonic grown and 24-hour-old biofilms of Enterococcus faecalis, Staphylococcus epidermidis, Staphylococcus aureus, and Streptococcus mutans. Results: AH Plus had high antibacterial activity toward all species investigated, both planktonic and in biofilms. However, the antibacterial activity was lost after 24 hours. TotalFill BC sealer showed marked antibacterial effect on planktonic bacteria up to 7 days after setting. TotalFill BC sealer had lower antibacterial activity against biofilms of S. aureus and E. faecalis compared with AH Plus when direct contact between the sealer and biofilm was investigated and for all species investigated when a membrane was used to separate the biofilm and sealer. Guttaflow 2 and RoekoSeal had no antibacterial activity against planktonic bacteria or bacteria in biofilms. Conclusions: Bacteria in biofilms showed higher susceptibility for AH Plus compared with TotalFill BC sealer during the first 24 hours after setting. Investigating the antibacterial activity of endodontic sealers and materials against bacteria in biofilms is highly important to evaluate the materials' ability to eradicate bacteria from the infected root canal.

Den norske tannlegeforenings Tidende, Mar 10, 2005

Den norske tannlegeforenings Tidende, Apr 17, 2019

Endodontic Topics, Nov 1, 2003

The pathogenic potential of spirochetes and their significance in the development of oral disease... more The pathogenic potential of spirochetes and their significance in the development of oral diseases, as well as in infections in other organs, have gained new interest for several reasons. First, these bacteria have the potential to be pathogenic because of their number and frequency at infected sites, their production of tissue irritants, their ability to invade tissues, their abundance in mixed infections, and their methods to evade host defense mechanisms. Second, of the microbial species that are associated with oral infections, spirochetes are infectious agents that cause severe diseases in other body sites. Third, during the past few years, new techniques have made it possible to obtain more information about spirochetes at the genetic level. Thereby, we have gained better knowledge of these bacteria, even though many cannot be cultured in the laboratory yet. Such knowledge includes the diversity of oral species as well as antigenic similarities between the species commonly found in the oral cavity and known pathogens such as the syphilis agent Treponema pallidum subsp. pallidum, Lyme disease agents Borrelia burgdorferi sensu lato group, and the swine dysentery agent Brachyspira (Serpulina) hyodysenteria. This review covers the main areas of what is known to date about Treponema. It focuses especially on factors related to their taxonomy, epidemiology, and biology, with special emphasis on their presence and possible role in endodontic infections.

Endodontic Topics, Nov 1, 2003

The science of oral microbiology is in a period of change from the era of bacterial cultivation t... more The science of oral microbiology is in a period of change from the era of bacterial cultivation to an era of molecular genetic methods and techniques. Already a significant body of new knowledge exists with regard to the oral flora in health and disease. Inevitably, this new knowledge has led to a better understanding of many oral diseases. In endodontics, the prevailing concepts are still to a great extent based on the results of the classical cultivation studies. However, a few groups have started to use molecular methods, and a new understanding of endodontic infections is presently evolving. Thus, the root canal infection clearly is more complex than revealed by cultivation methods alone, and both previously unidentified and uncultivable microorganisms have been detected by molecular methods. A reasonable estimate at present is that the infected root canal contains, not less than 10, but rather between 10 and 50 bacterial species which coincide well with the number of bacterial species normally found in a dental plaque sample and at different sites in the oral cavity. A further interesting finding in the studies using molecular techniques is that the microbiota of the infected root canal appears to be very similar to the flora of the periodontal pocket in patients with active periodontal disease. With regard to infection of periapical lesions in patients with asymptomatic apical periodontitis, electron microscopic and molecular methods have confirmed our cultivation findings that this is a common occurrence. Mature biofilms have been demonstrated on the external surfaces of root tips and in the form of sulfur granules within periapical granulomas. As in dental plaque, Actinomyces species appear to have a special role as scaffold builders in the development of sulfur granules. Other bacteria are then attracted to the site and a multibacterial granule (biofilm) develops. In addition, in situ hybridization studies show a variety of different bacteria and bacterial morphotypes in periapical lesions. With DNA-DNA hybridization between 11and 39 bacterial species have been recognized in the lesions, again confirming that in patients with active disease, the microbiotas of endodontic and periodontal infections are very similar. Thus, the recent findings demonstrate and confirm that the periapical endodontic lesion is not as hostile to microorganisms as many have thought. As clinicians we have to understand and accept that an infection might not be limited to the root of the tooth, but include the periapical lesion as well.

Clinical Oral Investigations, Jul 11, 2023

Objectives This study aimed to identify disease-related markers in persistent apical periodontiti... more Objectives This study aimed to identify disease-related markers in persistent apical periodontitis (PAP) biopsies and examine whether these were associated with comorbidities like rheumatoid arthritis (RA) and cardiovascular diseases (CVD). Materials and method The levels of the cytokines/chemokines GM-CSF,

Research Square (Research Square), Sep 22, 2022

, MIP-3α/CCL20 and TNF-α were determined in lesions from patients with persistent apical periodon... more , MIP-3α/CCL20 and TNF-α were determined in lesions from patients with persistent apical periodontitis (n = 20) and compared to healthy bone samples (n = 20). Results: We identi ed eleven cytokines to be differently expressed, and among them, IL-2, IL-6, IL-17E, IL-21, and IL-27 appeared to drive the discrepancy between the disease and healthy groups. The levels of T follicular helper (Tfh) cell promoting cytokines (IL-21, IL-6, IL-27) were enhanced while T helper (Th) 1 cell promoting cytokine (IL-2), Th2 cell promoting cytokine (IL-13), and Th17 cell promoting cytokine (IL-17E) were reduced in the PAP group. The data also indicate that Tfh cell differentiation (IL-21), along with Th1 (GM-CSF, IFNγ), Th2 (IL-13), and Th17 (GM-CSF) cell differentiation, might be increased in the subpopulation of patients suffering from rheumatoid arthritis, whereas no differences were found in patients with cardiovascular diseases. Conclusions: A cluster of potential cellular markers for PAP was identi ed. The lesions contained additional factors that might be associated with differentiation of various T cell populations. Clinical Relevance: Molecular analyses of PAP may result in identi cation of prognostic markers. Introduction: Root canal infection results in breakdown of the periapical bone and formation of an apical lesion which is manifested on X-ray by the formation of a periapical radiolucency. An apical lesion is a mass of in amed granulation tissue surrounded by an outer capsule of dense brous tissue [1]. Granulation tissue contains a variety of cells including immune cells such as lymphocytes (T cells and B cells). At dental educational institutions and in specialist practice, a success rate of endodontic treatment of 75-85% is shown in teeth with preoperative apical periodontitis (AP) [2-6]. Persistent apical periodontitis (PAP) is a chronic in ammatory disease that occurs when root canal treatment has not adequately eliminated the infection. PAP can be asymptomatic or symptomatic and is most often diagnosed by observing visible lesions on X-ray. Teeth with PAP can be treated by either nonsurgical endodontic retreatment or periapical surgery. Large apical lesions (> 5 mm) have showed lowered healing rate compared to smaller lesions (< 5 mm) [5, 7] and teeth with lesions > 5mm are more likely to be extracted [8]. Large lesions are also correlated with development of cysts [9]. The reduction of periapical bone, caused by an imbalance between osteoblast and osteoclast activity, may be modulated by cytokines [10]. Cytokines are signaling molecules that most cells produce in ±

Tissue Engineering Part B-reviews, May 23, 2023

International Endodontic Journal, May 1, 2020

Case reports can provide early information about new, unusual or rare disease(s), newer treatment... more Case reports can provide early information about new, unusual or rare disease(s), newer treatment strategies, improved therapeutic benefits and adverse effects of interventions or medications. This paper describes the process that led to the development of the Preferred Reporting Items for Case reports in Endodontics (PRICE) 2020 guidelines through a consensus-based methodology. A steering committee was formed with eight members (PD, VN, BC, PM, PS, EP, JJ and SP), including the project leaders (PD, VN). The steering committee developed an initial checklist by combining and modifying the items from the Case Report (CARE) guidelines and Clinical and Laboratory Images in Publications (CLIP) principles. A PRICE Delphi Group (PDG) and PRICE Face-to-Face Meeting Group (PFMG) were then formed. The members of the PDG were invited to participate in an online Delphi process to achieve consensus on the wording and utility of the checklist items and the accompanying flow chart that was created to complement the PRICE 2020 guidelines. The revised PRICE checklist and flow chart developed by the online Delphi process was discussed by the PFMG at a meeting held during the 19th European Society of Endodontology (ESE) Biennial Congress in Vienna, Austria, in September 2019. Following the meeting, the steering committee created a final version of the guidelines, which were piloted by several authors during the writing of a case report. In order to help improve the clarity, completeness and quality of case reports in Endodontics, we encourage authors to use the PRICE 2020 guidelines.

Objectives: This study aimed to identify disease-related markers in persistent apical periodontit... more Objectives: This study aimed to identify disease-related markers in persistent apical periodontitis (PAP) biopsies and examine whether these were associated with comorbidities. Materials and method: The levels of the cytokines GM-CSF, IFN-γ, IL-2, IL-6, IL-9, IL-10, IL-13, IL-15, IL-17E/IL-25, IL-21, IL-23, IL-27, IL-28A/IFN -λ2, IL-33, MIP-3α/CCL20 and TNF-α were determined in lesions from patients with persistent apical periodontitis (n = 20) and compared to healthy bone samples (n = 20). Results: We identified eleven cytokines to be differently expressed, and among them, IL-2, IL-6, IL-17E, IL-21, and IL-27 appeared to drive the discrepancy between the disease and healthy groups. The levels of T follicular helper (Tfh) cell promoting cytokines (IL-21, IL-6, IL-27) were enhanced while T helper (Th) 1 cell promoting cytokine (IL-2), Th2 cell promoting cytokine (IL-13), and Th17 cell promoting cytokine (IL-17E) were reduced in the PAP group. The data also indicate that Tfh cell diff...

Den norske tannlegeforenings Tidende, Apr 16, 2020

Kasuistikk • Ortograd rotfyllings te ra pi av unge ten ner med dens invaginatus: To ka sus Ortogr... more Kasuistikk • Ortograd rotfyllings te ra pi av unge ten ner med dens invaginatus: To ka sus Ortograd rotfyllings te ra pi av unge ten ner med dens invaginatus: To ka sus Line Rør slett Har der sen, Mar ga reth Kris ten sen Ot ter sen og Pia Tit te rud Sunde FORFATTERE Line Rørslett Hardersen, spesialist i endodonti, Avdeling for endodonti, Institutt for klinisk odontologi, Universitetet i Oslo. Margareth Kristensen Ottersen, spesialist i kjeve-og ansiktsradiologi, stipendiat. Avdeling for kjeve-og ansiktsradiologi, Institutt for klinisk odontologi, Universitetet i Oslo.

Clinical Oral Investigations, Aug 5, 2022

Dental Materials, Jun 1, 2022

European Journal of Oral Sciences, Jun 30, 2023

This study investigated the role of aging and changes in environmental conditions on selected pro... more This study investigated the role of aging and changes in environmental conditions on selected properties of a prototype radiopacified calcium silicate‐based cement (TZ‐base) with or without incorporation of silver nanoparticles or bioactive glass, and two commercial materials, Biodentine and intermediate restorative material. Materials were immersed in ultrapure water or fetal bovine serum for 28 days and were characterized with scanning electron microscopy and energy dispersive x‐ray analysis. Immersion media were either replaced weekly or not replenished at all and were assessed for alkalinity and calcium release after 1, 7, 14, 21, and 28 days; antibacterial effect against 2‐day monospecies biofilms; and cytotoxicity by the 3‐(4,5 dimethylthiazolyl‐2‐yl)‐2,5‐diphenyl tetrazolium bromide assay after 1, 7, or 28 days. Alkalinity, calcium release, antibacterial activity, and cell cytotoxicity increased over time when the medium was not changed but decreased with medium replenishment. Immersion in fetal bovine serum resulted in lower alkalinity, less bactericidal properties, and lower cytotoxicity of prototype cements and Biodentine than did water immersion. Biodentine and 20% bioactive glass‐containing cement had overall lower alkalinity, calcium release, and antibacterial activity than TZ‐base, and Biodentine was less cytotoxic than TZ‐base. In conclusion, exposure conditions and cement modifications significantly affected materials’ leaching properties. Exposure conditions warrant consideration when evaluating cements’ clinical properties.

Acta Odontologica Scandinavica, May 16, 2019

Journal of Functional Biomaterials, Oct 10, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

International Endodontic Journal, Dec 7, 2021

This is an open access article under the terms of the Creative Commons Attribution License, which... more This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

Acta Odontologica Scandinavica, Jan 27, 2021

Abstract Objective To evaluate the knowledge and insights of general dental practitioners regardi... more Abstract Objective To evaluate the knowledge and insights of general dental practitioners regarding endodontic diagnosis and treatment principles before and after attending a 2-days continuing education course. Materials and methods Sixty-seven dentists employed in the Public Dental Service in Møre and Romsdal county, Norway, were invited to a continuing education course in endodontics. Before and after the course, they answered a questionnaire weighing the importance of factors influencing the prognosis of endodontic treatment. The same questionnaire was answered by specialists in endodontics (n = 56; Spec Group) and a reference group consisting of general dental practitioners from both private and public practice (n = 21; Ref Group). The Test Group answered both before and after the course, while the Spec and Ref Groups completed the questionnaire once. The responses were compared using the Wilcoxon Sign test and Mann–Whitey U test. Results Of the 67 dentists in the Test Group, 49 (73%) completed the course and answered both questionnaires. Before attending the course, the Test Group differed significantly from the Spec Group in 18 out of 27 prognostic factors (p ≤ .05). After the course, there was only moderate improvement in the Test Group responses. On only three factors, they agreed significantly more with the specialists than before attending the course (p ≤ .05). After the Test Group participants had attended the course, their responses were comparable to the responses of the Ref Group. Conclusions A two-days continuing education course only marginally improved dentists’ level of knowledge and insights regarding the influence of prognostic factors in endodontics.

Journal of Endodontics, Apr 1, 2002

The periapical microbiota of 36 teeth with refractory apical periodontitis was investigated. None... more The periapical microbiota of 36 teeth with refractory apical periodontitis was investigated. None of the teeth had responded to conventional endodontic or long-term (> 6 months), calcium-hydroxide treatment. Eight patients had received antibiotics systemically. After anaerobic culture, a total of 148 microbial strains were detected among 67 microbial species. One of the 36 lesions was culturenegative. Approximately half (51.0%) of the bacterial strains were anaerobic. Gram-positive species constituted 79.5% of the flora. Facultative organisms, such as Staphylococcus, Enterococcus, Enterobacter, Pseudomonas, Stenotrophomonas, Sphingomonas, Bacillus, or Candida species were recovered from 27 of the lesions (75%). Sulfur granules were found in 9 lesions (25%). In these granules Actinomyces israelii, A. viscosus, A. naeslundii, and A. meyeri were identified. Other bacterial species, both Gram-positive and Gramnegative, were detected in the granules as well. Two sulfur granules did not contain Actinomyces. Scanning electron microscopy demonstrated rodand spirochete-like cells in the granules, and transmission electron microscopy revealed organisms with copious amounts of extracellular material. Outer membrane vesicles were also seen. Some of the granules were calcified. This study demonstrated a wide variety of microorganisms, particularly Gram-positive ones, in the periapical lesions of teeth with refractory apical periodontitis.

Journal of Medical Virology, 2008

Periodontitis is presumably caused by bacterial infection, but it has been shown recently that af... more Periodontitis is presumably caused by bacterial infection, but it has been shown recently that affected tissue often contains human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV). The present study was initiated to evaluate the role of these viruses in the pathogenesis of periodontitis. HCMV and EBV were quantified in 40 apical and 25 marginal periodontitis samples using real time PCR. In situ hybridization or immunohistochemistry was carried out on apical samples to detect viral presence within cells. A possible association with relevant bacteria was examined. Of the apical periodontitis samples, 50% contained EBV, while none contained HCMV. Of the marginal periodontitis samples, 40% were positive for EBV and 12% for HCMV. With one exception, however, the amount of virus was close to the detection limits. EBV was only detected in 1 out of 15 healthy periodontium samples. Immunohistochemistry and in situ hybridization were all negative. Significant associations were found between periodontal EBV and the presence of Aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis. Although there was an obvious association of the virus with clinical samples, it seems unlikely that these viruses play a major role in the pathogenesis of periodontitis of the average patient. Their presence may reflect that the clinical samples contain more blood or saliva compared to controls, or an accumulation of lymphoid cells harboring virus in the inflamed tissue.

Journal of Endodontics, 2018

Introduction: The aim of this study was to investigate the antibacterial activity of 4 endodontic... more Introduction: The aim of this study was to investigate the antibacterial activity of 4 endodontic sealers against bacteria planktonic grown or in biofilms commonly detected from persistent and secondary endodontic infections. Methods: The antibacterial activity of the sealers AH Plus, TotalFill BC sealer, RoekoSeal, and Guttaflow 2 was investigated for planktonic grown and 24-hour-old biofilms of Enterococcus faecalis, Staphylococcus epidermidis, Staphylococcus aureus, and Streptococcus mutans. Results: AH Plus had high antibacterial activity toward all species investigated, both planktonic and in biofilms. However, the antibacterial activity was lost after 24 hours. TotalFill BC sealer showed marked antibacterial effect on planktonic bacteria up to 7 days after setting. TotalFill BC sealer had lower antibacterial activity against biofilms of S. aureus and E. faecalis compared with AH Plus when direct contact between the sealer and biofilm was investigated and for all species investigated when a membrane was used to separate the biofilm and sealer. Guttaflow 2 and RoekoSeal had no antibacterial activity against planktonic bacteria or bacteria in biofilms. Conclusions: Bacteria in biofilms showed higher susceptibility for AH Plus compared with TotalFill BC sealer during the first 24 hours after setting. Investigating the antibacterial activity of endodontic sealers and materials against bacteria in biofilms is highly important to evaluate the materials' ability to eradicate bacteria from the infected root canal.

Den norske tannlegeforenings Tidende, Mar 10, 2005

Den norske tannlegeforenings Tidende, Apr 17, 2019

Endodontic Topics, Nov 1, 2003

The pathogenic potential of spirochetes and their significance in the development of oral disease... more The pathogenic potential of spirochetes and their significance in the development of oral diseases, as well as in infections in other organs, have gained new interest for several reasons. First, these bacteria have the potential to be pathogenic because of their number and frequency at infected sites, their production of tissue irritants, their ability to invade tissues, their abundance in mixed infections, and their methods to evade host defense mechanisms. Second, of the microbial species that are associated with oral infections, spirochetes are infectious agents that cause severe diseases in other body sites. Third, during the past few years, new techniques have made it possible to obtain more information about spirochetes at the genetic level. Thereby, we have gained better knowledge of these bacteria, even though many cannot be cultured in the laboratory yet. Such knowledge includes the diversity of oral species as well as antigenic similarities between the species commonly found in the oral cavity and known pathogens such as the syphilis agent Treponema pallidum subsp. pallidum, Lyme disease agents Borrelia burgdorferi sensu lato group, and the swine dysentery agent Brachyspira (Serpulina) hyodysenteria. This review covers the main areas of what is known to date about Treponema. It focuses especially on factors related to their taxonomy, epidemiology, and biology, with special emphasis on their presence and possible role in endodontic infections.

Endodontic Topics, Nov 1, 2003

The science of oral microbiology is in a period of change from the era of bacterial cultivation t... more The science of oral microbiology is in a period of change from the era of bacterial cultivation to an era of molecular genetic methods and techniques. Already a significant body of new knowledge exists with regard to the oral flora in health and disease. Inevitably, this new knowledge has led to a better understanding of many oral diseases. In endodontics, the prevailing concepts are still to a great extent based on the results of the classical cultivation studies. However, a few groups have started to use molecular methods, and a new understanding of endodontic infections is presently evolving. Thus, the root canal infection clearly is more complex than revealed by cultivation methods alone, and both previously unidentified and uncultivable microorganisms have been detected by molecular methods. A reasonable estimate at present is that the infected root canal contains, not less than 10, but rather between 10 and 50 bacterial species which coincide well with the number of bacterial species normally found in a dental plaque sample and at different sites in the oral cavity. A further interesting finding in the studies using molecular techniques is that the microbiota of the infected root canal appears to be very similar to the flora of the periodontal pocket in patients with active periodontal disease. With regard to infection of periapical lesions in patients with asymptomatic apical periodontitis, electron microscopic and molecular methods have confirmed our cultivation findings that this is a common occurrence. Mature biofilms have been demonstrated on the external surfaces of root tips and in the form of sulfur granules within periapical granulomas. As in dental plaque, Actinomyces species appear to have a special role as scaffold builders in the development of sulfur granules. Other bacteria are then attracted to the site and a multibacterial granule (biofilm) develops. In addition, in situ hybridization studies show a variety of different bacteria and bacterial morphotypes in periapical lesions. With DNA-DNA hybridization between 11and 39 bacterial species have been recognized in the lesions, again confirming that in patients with active disease, the microbiotas of endodontic and periodontal infections are very similar. Thus, the recent findings demonstrate and confirm that the periapical endodontic lesion is not as hostile to microorganisms as many have thought. As clinicians we have to understand and accept that an infection might not be limited to the root of the tooth, but include the periapical lesion as well.