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Hydrogen peroxide is an oxidative agent commonly used for dental bleaching procedures. The structural and biochemical responses of enamel, dentin, and pulp tissues to the in vivo bleaching of human (n = 20) premolars were investigated in this study. Atomic force microscopy (AFM) was used to observe enamel nanostructure. The chemical composition of enamel and dentin was analyzed by infrared spectroscopy (FTIR). The enzymatic activities of dental cathepsin B and matrix metalloproteinases (MMPs) were monitored with fluorogenic substrates. The amount of collagen in dentin was measured by emission of collagen autofluorescence with confocal fluorescence microscopy. The presence of Reactive Oxygen Species (ROS) in the pulp was evaluated with a fluorogenic 2′,7′-dichlorodihydrofluorescein diacetate (DCFDA) probe. Vital bleaching of teeth significantly altered all tested parameters: AFM images revealed a corrosion of surface enamel nanostructure; FTIR analysis showed a loss of carbonate and proteins from enamel and dentin, along with an increase in the proteolytic activity of cathepsin-B and MMPs; and there was a reduction in the autofluorescence of collagen and an increase in both cathepsin-B activity and ROS in pulp tissues. Together, these results indicate that 35% hydrogen peroxide used in clinical bleaching protocols dramatically alters the structural and biochemical properties of dental hard and soft pulp tissue. [ABSTRACT FROM PUBLISHER]

Auto-degradation of collagen matrices occurs within hybrid layers created by contemporary dentin bonding systems, by the slow action of host-derived matrix metalloproteinases (MMPs). This study tested the null hypothesis that there are no differences in the activities of MMP-2 and -9 after treatment with different etch-and-rinse or self-etch adhesives. Tested adhesives were: Adper Scotchbond 1XT (3M ESPE), PQ1 (Ultradent), Peak LC (Ultradent), Optibond Solo Plus (Kerr), Prime&Bond NT (Dentsply) (all 2-step etch-and-rinse adhesives), and Adper Easy Bond (3M ESPE), Tri-S (Kuraray), and Xeno-V (Dentsply) (1-step self-etch adhesives). MMP-2 and -9 activities were quantified in adhesive-treated dentin powder by means of an activity assay and gelatin zymography. MMP-2 and MMP-9 activities were found after treatment with all of the simplified etch-and-rinse and self-etch adhesives; however, the activation was adhesive-dependent. It is concluded that all two-step etch-and-rinse and the one-step self-etch adhesives tested can activate endogenous MMP-2 and MMP-9 in human dentin. These results support the role of endogenous MMPs in the degradation of hybrid layers created by these adhesives. [ABSTRACT FROM PUBLISHER]

This study determined if dentin proteases are denatured by phosphoric acid (PA) used in etch-and-rinse dentin adhesives. Dentin beams were completely demineralized with EDTA for 30 days. We “acid-etched” experimental groups by exposing the demineralized dentin beams to 1, 10, or 37 mass% PA for 15 sec or 15 min. Control beams were not exposed to PA but were incubated in simulated body fluid for 3 days to assay their total endogenous telopeptidase activity, by their ability to solubilize C-terminal crosslinked telopeptides ICTP and CTX from insoluble dentin collagen. Control beams released 6.1 ± 0.8 ng ICTP and 0.6 ± 0.1 ng CTX/mg dry-wt/3 days. Positive control beams pre-incubated in p-aminophenylmercuric acetate, a compound known to activate proMMPs, released about the same amount of ICTP peptides, but released significantly less CTX. Beams immersed in 1, 10, or 37 mass% PA for 15 sec or 15 min released amounts of ICTP and CTX similar to that released by the controls (p > 0.05). Beams incubated in galardin, an MMP inhibitor, or E-64, a cathepsin inhibitor, blocked most of the release of ICTP and CTX, respectively. It is concluded that PA does not denature endogenous MMP and cathepsin activities of dentin matrices. [ABSTRACT FROM PUBLISHER]

Purpose: To test, in vitro, the null hypothesis that there was no difference in the ultrastructure of adhesive-bonded, acid-etched dentin aged under accelerated conditions in mineral oil or artificial saliva. Methods: Beams of human dentin bonded with three total-etch adhesives were retrieved from the two storage media after 3 years and prepared for transmission electron microscopy. Results: Hybrid layers from specimens aged in mineral oil exhibited structural integrity of the collagen network. Conversely, abnormal hybrid layers were seen in specimens aged in artificial saliva, with progressive disintegration of the fibrillar network to the extent that it was beyond detection by collagen staining. Self-destruction of collagen matrices can occur in resin-infiltrated dentin, and to a lesser degree, in mineralized dentin in the absence of bacterial or salivary enzymes. [ABSTRACT FROM AUTHOR]

Background: Collagen XVIII is a ubiquitous basement membrane (BM) component and a precursor of endostatin. Methods: Using immunohistochemistry and in situ hybridization, we studied the expression and localization of collagen XVIII in different stages of normal oral wound healing, epithelial dysplasia and squamous cell carcinoma (SCC). Results: In mild epithelial dysplasias collagen XVIII appeared as a continuous signal in the BM, whereas in severe epithelial dysplasias and in the invasive areas of oral SCCs collagen XVIII was absent. In situ hybridization showed that collagen XVIII mRNA expression did not decrease in severe dysplasia or oral carcinoma samples when compared with the mild dysplasias. Conclusions: The results indicate that the absence of collagen XVIII protein in severe oral dysplasias is related to the processing of the protein rather than to changes in mRNA expression. [ABSTRACT FROM AUTHOR]

MT1-MMP is a cell-membrane-bound metalloenzyme that activates other proMMPs such as proMMP-2 and -13. We studied MT1-MMP expression in mature human odontoblasts and pulp tissue, the regulation of MT1-MMP expression by growth factors TGF-β1 and BMP-2, and the activation of odontoblast-derived MMP-20 by MT1-MMP. MT1-MMP mRNA is expressed by native and cultured mature human odontoblasts and pulp tissue. Western blot analysis of human odontoblasts and pulp tissue detects 65- and 51-kDa pro- and active forms of MT1-MMP, and smaller truncated MT1-MMP forms. BMP-2 down-regulates MT1-MMP expression in odontoblasts and pulp tissue, while TGF-β1, alone or with BMP-2, decreases MT1-MMP mRNA levels only slightly. We also demonstrate that MT1-MMP is capable of converting proMMP-20 into a form corresponding to the active MMP-20. In conclusion, this study demonstrates the expression and differential regulation of MT1-MMP in human dentin-pulp complex cells, and the activation of MMP-20 by MT1-MMP. [ABSTRACT FROM AUTHOR]

The significance of systemic dietary effects on the response of the pulpo-dentinal complex to dentinal caries was examined. Weanling rats were divided into high sucrose or control diet groups both with and without cariogenic bacterial inoculation. At the onset, tetracycline was injected to mark the dentin formation during the experiment. After 5-6 week, mandibular molars were sectioned sagittally. The areas of dentin formed during the experiment and those of dentinal caries were quantified separately in the first and second molars. In the control diet groups the area of dentin was significantly greater under carious fissures, whereas in the high sucrose diet groups the area of dentin formed did not differ between intact and carious fissures. The high sucrose diet resulted in a significantly smaller area of dentin formation than did the control diet. The high sucrose diet with cariogenic bacterial inoculation resulted in the greatest area of dentinal caries. With the control diet a positive response against dentinal caries occurs, but the high dietary sucrose content impairs the defensive reactions of pulpo-dentinal complex against dentinal caries. These findings add further evidence of the importance of the local endogenous factors of caries progression. [ABSTRACT FROM AUTHOR]

High sucrose diets alter mineral metabolism in humans and animals. We examined the effect of a high sucrose diet on bone growth, composition and mechanical strength in growing rats. Weanling Wistar rats received a high sucrose (43 g/100 g) diet (9 males, 11 females). In the control diet (8 males, 8 females), sucrose was replaced with potato starch, providing an equal energy value. At the onset of the experiment, bones were marked by tetracycline. After 5 wk, the tibias and femurs were weighed, and maximum breaking strengths were determined. Tibias were cut at the tibia-fibular junction; the widths of the bone at the start of the experiment, the periosteal bone formation during the experiment, the widths of the medullary cavity and the final bone width were determined from tetracycline lines. Bone ash weight, Ca and P contents were determined. The breaking strengths of both bones were significantly lower in the sucrose-fed groups of both sexes. In females, the weight of both bones and the final width of the tibias were significantly lower in the sucrose-fed group. The Ca concentration in both bones and the P concentration in tibias were significantly lower in the sucrose-fed group. It was concluded that the metabolic interference induced by sucrose was the reason for the differences. The alterations were more pronounced in females, but independent of body weight. [ABSTRACT FROM AUTHOR]

Odontoblasts cannot be cultured by traditional cell culture methods, thus restricting in vitro studies. Here we present an organ culture method for human odonto-blasts that utilizes the pulp chamber as a culture crucible. Crowns of human third molars were dissected, pulp was gently removed, and the odontoblasts attached to and in the walls of the pulp chambers were cultured in serum-free OPTI- MEM medium, or DMEM/Ham's F12 medium containing 10% serum. Pulp tissues were cultured separately. Cell content and morphology were analyzed by SEM, and the removed pulps were examined by light microscopy. Proteins secreted into the medium with or without TGF-β1 supplementation were metabolically labeled with [35S]methionine, and the total protein content was assessed by TCA precipitation and SDS-PAGE/fluorography. To assess the role of gelatinolytic enzymes on dentin matrix remodeling, we used enzymography to analyze the effect of TGF-β1 on gelatinase A and B expression. SEM revealed odontoblasts in pulp chambers after 5 days of culture, with only few or no fibroblasts, and no alterations in the odontoblast cell morphology or differences between the cells cultured in serum-free and serum-containing media. Rarely were any odontoblasts present in pulp tissue. Radiolabeling revealed protein synthesis and secretion until day 6 in both the odontoblast and pulp cultures, with no marked differences between TGF-β1-treated and control cultures. The level of gelatinase A remained constant up to 7 days, while gelatinase B expression was always low and decreased with time in culture. However, gelatinase B levels were markedly increased upon TGF-βl treatment of cells and remained high to day 7. The results suggest that this method provides a novel technique for the study of human odontoblasts in vitro and that odontoblasts can be cultured even in serum-free conditions. [ABSTRACT FROM AUTHOR]

An introduction is presented in which the editor discusses various reports within the issue on topics including the relationship between cardiovascular disease or diabetes and apical periodontitis, and potential virulence mechanisms of endodontic microbes they could contribute to persisting disease.

A letter to the editor is presented in response to the article "CpG ODN-Induced Matrix Metalloproteinase-13 Expression Is Mediated via Activation of the ERK and NF-κΒ Signalling Pathways in Odontoblast Cells" in a 2013 issue.

The author reflects on the deoxyribonucleic acid (DNA) microarray as the most applied analysis method in molecular biology. He argues that published informations regarding microarray experiments and results, especially in researches on dentistry, are not completely discussed in journals which would not impart knowledge to the readers. An overview of databases created by microarray gene expression databases (MGED) society and which are established at the U.S. and Great \ offered.

Abstract Aim To examine the occurrence of Candida spp. in refractory periapical granulomas. Methodology One hundred and three surgically removed periapical granulomas were subjected to molecular analysis for the occurrence of Candida albicans . DNA was extracted from the samples using a modified phenol/chloroform/isoamyl alcohol method and was subjected to polymerase chain reaction (PCR) with OPA-03 and repetitive sequence (GACA)[sub 4] primers. The PCR products were separated in agarose gel electrophoresis, stained with ethidium bromide, visualized using UV light and the sequences were analysed. Samples indicating possible occurrence of Candida were further investigated by histological and immunohistological methods. Periodic acid–Shiff staining (PAS) was used to detect yeast cells and hyphae, and specific monoclonal antibodies to recognize high molecular mass mannoproteins present in the C. albicans cell wall. DNA extraction was controlled by running PCR using β-actin primers (a housekeeping gene). C. albicans CCUG19915, C. tropicalis ATCC750, C. krusei ATCC6258, C. guilliermondii ATCC6260 and C. glabrata CCUG32725 served as positive controls in PCR. A tissue preparation of chronic atrophic candidosis in oral buccal mucosa served as a positive control for histological and immunohistological examinations. Results Polymerase chain reaction with β-actin primers indicated successful DNA extraction in 68 out of 103 samples. The majority of the samples (50) were negative whereas 18 of the samples showed PCR products indicating possible occurrence of Candida spp. PAS-staining and immunohistological examination of these samples were, however, negative. Further analysis of the PCR products revealed sequences not typical for Candida spp. Conclusions Candida spp. do not seem to occur in periapical granuloma. [ABSTRACT FROM AUTHOR]

Abstract Wahlgren J, Salo T, Teronen O, Luoto H, Sorsa T, Tjäderhane. Matrix metalloproteinase-8 (MMP-8) in pulpal and periapical inflammation and periapical root-canal exudates. International Endodontic Journal , 35 , 897–904, 2002. Aim To study the presence, levels and molecular forms of matrix metalloproteinase (MMP) -8 (collagenase-2) in pulpal and periapical inflammation, and the changes in MMP-8 levels in root-canal exudates during root-canal treatment. Methodology Periapical exudate samples were collected from 11 necrotic teeth with radiographically verified periapical periodontitis during three root-canal treatment visits with interappointment calcium hydroxide (Ca(OH)2 ) medication. MMP-8 levels and molecular forms were analyzed with immunofluorescent assay (IFMA) and Western immunoblot. Inflamed pulp tissue and periapical granuloma tissue (n = 10 for both) were obtained from other patients and used for MMP-8 immunohistochemical (IHC) staining. Results The periapical exudate samples demonstrated marked differences in MMP-8 levels between the teeth in the first visit and significant decrease in MMP-8 levels during the root-canal treatment (P = 0.0107). One specimen failed to show a decrease in MMP-8 below 1000 ng mL-1 ; a vertical root fracture was later diagnosed and the tooth extracted. IHC staining showed that in addition to PMN-leucocytes, macrophages and plasma cells produced MMP-8 in pulp and periapical granulomas. Conclusions The findings demonstrate the presence of MMP-8 in the inflamed pulp and periapical tissue, indicating that MMP-8 has a role in pulpal and periapical inflammation, most likely participating in tissue extracellular matrix degradation. They further indicate that MMP analysis from periapical exudate could be used to indicate and monitor inflammatory activity and the success of treatment in teeth with periapical lesions. [ABSTRACT FROM AUTHOR]

Aim To improve an enzymatic method previously used for isolation of rat odontoblasts to isolate viable mature human odontoblasts. Methodology Collagenase I, collagenase I/hyaluronidase mixture and hyaluronidase were used to extract mature human odontoblasts from the pulp chamber. Detachment of odontoblasts from dentine was determined with field emission scanning electron microscopy ( FESEM) and to analyse the significance of differences in tubular diameter, and the t-test was used. MTT-reaction was used to analyse cell viability, and nonparametric Kruskal-Wallis and Mann-Whitney post hoc tests were used to analyse the data. Immunofluorescent staining of dentine sialoprotein ( DSP), aquaporin-4 ( AQP4) and matrix metalloproteinase-20 ( MMP-20) and quantitative PCR (qPCR) of dentine sialophosphoprotein ( DSPP) were used to confirm the odontoblastic nature of the cells. Results MTT-reaction and FESEM demonstrated collagenase I/hyaluronidase resulted in more effective detachment and higher viability than collagenase I alone. Hyaluronidase alone was not able to detach odontoblasts. Immunofluorescence revealed the typical odontoblastic-morphology with one process, and DSP, AQP4 and MMP-20 were detected. Quantitative PCR of DSPP confirmed that the isolated cells expressed this odontoblast-specific gene. Conclusion The isolation of viable human odontoblasts was successful. The cells demonstrated morphology typical for odontoblasts and expressed characteristic odontoblast-type genes and proteins. This method will enable new approaches, such as apoptosis analysis, for studies using fully differentiated odontoblasts. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to evaluate clinical and radiological findings and the role of periapical infection and antecedent dental treatment of infected focus teeth in odontogenic maxillofacial abscesses requiring hospital care. Materials and methods: In this retrospective cohort study, we evaluated medical records and panoramic radiographs during the hospital stay of patients ( n = 60) admitted due to odontogenic maxillofacial infection originating from periapical periodontitis. Results: Twenty-three (38 %) patients had received endodontic treatment and ten (17 %) other acute dental treatment. Twenty-seven (45 %) had not visited the dentist in the near past. Median age of the patients was 45 (range 20-88) years and 60 % were males. Unfinished root canal treatment (RCT) was the major risk factor for hospitalisation in 16 (27 %) of the 60 cases ( p = .0065). Completed RCT was the source only in 7 (12 %) of the 60 cases. Two of these RCTs were adequate and five inadequate. Conclusions: The initiation of inadequate or incomplete primary RCT of acute periapical periodontitis appears to open a risk window for locally invasive spread of infection with local abscess formation and systemic symptoms. Thereafter, the quality of the completed RCT appears to have minor impact. However, a considerable proportion of the patients had not received any dental treatment confirming the importance of good dental health. Thus, thorough canal debridement during the first session is essential for minimising the risk for spread of infection in addition to incision and drainage of the abscess. If this cannot be achieved, tooth extraction should be considered. Clinical relevance: Incomplete or inadequate canal debridement and drainage of the abscess may increase the risk for spread of endodontic infection. [ABSTRACT FROM AUTHOR]

This position statement represents a consensus of an expert committee convened by the European Society of Endodontology (ESE) on the endodontic management of traumatized permanent teeth. A recent comprehensive review with detailed background information provides the basis for this position statement (Krastl et al. 2021, International Endodontic Journal, https://doi.org/10.1111/iej.13508). The statement is based on current scientific evidence as well as the expertise of the committee. Complementing the recently revised guidelines of the International Association of Dental Traumatology, this position statement aims to provide clinical guidance for the choice of the appropriate endodontic approach for traumatized permanent teeth. Given the dynamic nature of research in this area, this position statement will be updated at appropriate intervals. [ABSTRACT FROM AUTHOR]

The pulp plays a key role in the treatment of traumatic dental injuries (TDIs) and is strongly associated with the outcome, particularly in severe cases. A correct pulp diagnosis is essential as it forms the basis for developing the appropriate management strategy. However, many TDIs are complex, and their treatment requires a profound knowledge of the physiological and pathological responses of the affected tissues. This comprehensive review will look at the dentine–pulp complex and its interaction with the surrounding tissues following TDIs. The literature up to 2020 was reviewed based on several searches on PubMed and the Cochrane Library using relevant terms. In addition to the recently revised guidelines of the International Association of Dental Traumatology, this article aims to provide background information with a focus on endodontic aspects and to gather evidence on which a clinician can make decisions on the choice of the appropriate endodontic approach for traumatized permanent teeth. [ABSTRACT FROM AUTHOR]

Aim: To study whether oral parameters such as endodontic infections, root canal fillings, number of teeth or wearing removable dentures at baseline are associated with cardiovascular‐ and all‐cause mortality in a follow‐up of approximately 8 years. Methodology: The Finnish Parogene cohort consists of 508 Finnish adults (mean age 63.3 years, SD 9.1) with cardiac symptoms, all of whom had undergone coronary angiography for accurate baseline coronary status. Extensive clinical and radiographic oral examinations were performed, and additional data were acquired from medical records and questionnaires. Root canal fillings and endodontic lesions, as well as their co‐occurrence, were determined from panoramic radiographs. The mortality data were assessed via record linkage with the Finnish Causes of Death register (mean follow‐up time 7.81 years, SD 1.45 years). A total of n = 471 dentate patients were included in the statistical analyses. Results: A total of n = 69 deaths were recorded, of which n = 41 were due to cardiovascular diseases (CVDs, ICD‐10 I00–I99). The deceased had fewer root canal fillings (mean 1.57; SD 1.64 vs. mean 2.30; SD 2.34, P = 0.03) than the survivors. The number of missing teeth was associated with smoking, occluded coronary arteries and diabetes. Cox regression with Firth's penalized maximum‐likelihood method using age as timescale revealed an inverse association (HR; 95%CI) between mortality and number of teeth (all‐cause 0.91; 0.86–0.96, CVD mortality 0.89; 0.83–0.96), use of removable dentures (all‐cause 0.24; 0.09–0.62, CVD mortality 0.20; 0.06–0.72), root canal fillings (all‐cause 0.82; 0.70–0.94, CVD mortality 0.79; 0.63–0.96) and having root canal fillings in all teeth with apical rarefactions (all‐cause 0.27; 0.06–0.79, CVD mortality 0.09; 0.01–0.63), when gender, smoking, occluded coronary arteries, periodontal inflammatory burden index and the number of teeth were adjusted for. Conclusions: The number of missing teeth appeared to be the strongest predictor of mortality in this study, whereas endodontic infections per se had no independent association. Nevertheless, signs of professional intervention in these problems, such as root canal fillings and removable dentures, appeared to be associated with improved survival, which might partly be explained by the utilization of healthcare services. [ABSTRACT FROM AUTHOR]

• MTA and Biodentine exhibit similar immediate microleakage regardless of irrigant. • Biomineralization does not prevent the increase in leakage with hCSC materials. • The effect of irrigant on long-term leakage and bond strength is material-dependent. To evaluate the long-term effect of chlorhexidine (CHX) and dimethyl sulfoxide (DMSO) on the sealing ability and biomineralization of two different calcium silicate cements (CSC) in root canal. Sixty human third molar root canals were obturated with ProRoot MTA or Biodentine. Before obturation the canals were irrigated with saline (control), 2% CHX or 5% DMSO. Microleakage was tested after three days and after six months. After additional six months (12 months after root filling) the roots were cut into 2 mm thick dentine discs. The discs were stored in artificial saliva for one year. The bond strength was measured with the push-out method, and the failure mode was evaluated with a stereomicroscope. The most apical disc of each tooth was used for Vickers hardness test. No significant differences between the groups was found in initial microleakage. The leakage increased significantly during the 6-month storage in all groups except in Biodentine-CHX group and Biodentine-DMSO group. CHX and DMSO irrigation significantly increased the leakage with ProRoot MTA with time, but there was no statistically significant difference compared to the ProRoot MTA-control group at six months' time point. CHX significantly reduced the push-out bond strength of ProRoot MTA. With Biodentine irrigation with CHX or DMSO resulted with significantly higher push-out strength compared to the Biodentine control group. Fracture analysis showed statistically significant difference in the distribution of the fractures between the groups, but neither CHX nor DMSO change the fracture pattern statistically significantly. With Vickers hardness test ProRoot MTA with and without DMSO as the final irrigant showed significantly higher dentin hardness than any Biodentine-group. Considering that aging increased the leakage in all groups except with Biodentine-DMSO and the differences in the push-out strength and surface microhardness data, it appears that the time-related biomineralizing effect of MTA and Biodentine does not improve sealing to dentin. CHX significantly reduced ProRoot MTA bond strength and increased pure adhesive failures with both cements. [ABSTRACT FROM AUTHOR]

The overuse of antibiotics and the emergence of antibiotic-resistant bacterial strains is a global concern. This concern is also of importance in terms of the oral microbiota and the use of antibiotics to deal with oral and dental infections. The aim of this paper was to review the current literature on the indications and use of antibiotics and to make recommendations for their prescription in endodontic patients. Odontogenic infections, including endodontic infections, are polymicrobial, and in most cases, the prescription of antibiotics is empirical. This has led to the increasing use of broad-spectrum antibiotics even in cases where antibiotics are not indicated, such as symptomatic irreversible pulpitis, necrotic pulps and localized acute apical abscesses. In case of discrete and localized swelling, the primary aim is to achieve drainage without additional antibiotics. Adjunctive antibiotic treatment may be necessary in the prevention of the spread of infection, in acute apical abscesses with systemic involvement and in progressive and persistent infections. Medically compromised patients are more susceptible to complication arising from odontogenic infections and antimicrobials have a more specific role in their treatment. Therefore, antibiotics should be considered in patients having systemic diseases with compromised immunity or in patients with a localized congenital or acquired altered defence capacity, such as patients with infective endocarditis, prosthetic cardiac valves or recent prosthetic joint replacement. Penicillin VK, possibly combined with metronidazole to cover anaerobic strains, is still effective in most cases. However, amoxicillin (alone or together with clavulanic acid) is recommended because of better absorption and lower risk of side effects. In case of confirmed penicillin allergy, lincosamides such as clindamycin are the drug of choice. [ABSTRACT FROM AUTHOR]

Objectives To evaluate the cytotoxicity of dimethyl sulfoxide (DMSO) on the repair-related activity of cultured odontoblast-like MDPC-23 cells. Methods Solutions with different concentrations of DMSO (0.05, 0.1, 0.3, 0.5 and 1.0 mM), diluted in culture medium (DMEM), were placed in contact with MDPC-23 cells (5 × 104 cells/cm 2 ) for 24 h. Eight replicates ( n = 8) were prepared for each solutions for the following methods of analysis: violet crystal dye for cell adhesion (CA), quantification of total protein (TP), alizarin red for mineralization nodules formation (MN) and cell death by necrosis (flow cytometry); while twelve replicates ( n = 12) were prepared for viable cell number (Trypan Blue) and cell viability (MTT assay). Data were analyzed by ANOVA and Tukey or Kruskal–Wallis and Mann–Whitney's tests ( p < 0.05). Results Cell viability, adhesion and percentage of cell death by necrosis were not affected by DMSO at any concentration, with no statistical significant difference among the groups. A significant reduction in total protein production was observed for 0.5 and 1.0 mM of DMSO compared to the control while increased mineralized nodules formation was seen only for 1.0 mM DMSO. Significance: DMSO caused no or minor cytotoxic effects on the pulp tissue repair-related activity of odontoblast-like cells. [ABSTRACT FROM AUTHOR]

Aim To study the expression of toll-like receptors ( TLR) -3, -7, -8 and -9 as well as interferon receptors alpha and gamma ( IFNAR1/ IFNAR2 and IFNGR1/ IFNGR2), which play important roles in the defence against viruses. Methodology DNA microarray and quantitative PCR analyses of TLR3, -7, -8 and -9 as well as IFNAR1/ IFNAR2 and IFNGR1/ IFNGR2 genes in mature native human odontoblasts and pulp were performed. Immunohistochemistry was used to confirm TLR8 protein in odontoblasts of healthy and carious human teeth. Results TLR3, -7, -8 and -9 mRNAs were detected both in odontoblasts and in pulp, but TLR8 expression level was higher in the odontoblasts. IFNAR and IFNGR expression was observed in both tissues. Immunohistochemical analysis of healthy teeth revealed positive TLR8 staining in the pre-dentine and the dentine but varying staining patterns in the different portions of tooth. Lighter TLR8 staining was observed in dentine of mildly carious teeth. In teeth with carious lesions extending into the mid-dentine, only very weak staining was detected. Conclusions The finding of these virus-recognition-related genes in odontoblasts strengthens the view that odontoblasts participate in the immune response of the dentine-pulp complex. [ABSTRACT FROM AUTHOR]

The amino acid derivative 2-hydroxyisocaproic acid (HICA) is a nutritional additive used to increase muscle mass. Low levels can be detected in human plasma as a result of leucine metabolism. It has broad antibacterial activity but its efficacy against pathogenic fungi is not known. The aim was to test the efficacy of HICA against Candida and Aspergillus species. Efficacy of HICA against 19 clinical and reference isolates representing five Candida and three Aspergillus species with variable azole antifungal sensitivity profiles was tested using a microdilution method. The concentrations were 18, 36 and 72 mg ml−1. Growth was determined spectrophotometrically for Candida isolates and by visual inspection for Aspergillus isolates, viability was tested by culture and impact on morphology by microscopy. HICA of 72 mg ml−1 was fungicidal against all Candida and Aspergillus fumigatus and Aspergillus terreus isolates. Lower concentrations were fungistatic. Aspergillus flavus was not inhibited by HICA. HICA inhibited hyphal formation in susceptible Candida albicans and A. fumigatus isolates and affected cell wall integrity. In conclusion, HICA has broad antifungal activity against Candida and Aspergillus at concentrations relevant for topical therapy. As a fungicidal agent with broad-spectrum bactericidal activity, it may be useful in the topical treatment of multispecies superficial infections. [ABSTRACT FROM AUTHOR]

To develop an automatic system for utilizing electronic dental records, a data mining system to extract the diagnostic and treatment codes from the records for an intermediate file and automatic drawing of Kaplan-Meier-type survival curves was first created. Then this intermediate file was analyzed with SAS software for the scientific determination of Kaplan-Meier survival of tooth/surface-specific healthy time and survival of restorations in each permanent tooth, health center, and age cohort and also combined. All patients born in 1985, 1990 or 1995 in 28 health centers in Finland were analyzed. Patients classified as caries-active were those who had caries in any first permanent molar under the age of 8 years, while resistant patients did not have caries in these teeth before 10 years. In the younger age cohorts, a shortening of survival of caries-free teeth was seen. The shortest caries-free survival was seen in mandibular and maxillary molars in the youngest age cohort. Occlusal surfaces of molars determined their caries onsets and proximal caries occurred equally in molars, incisors and premolars, whereas canines or mandibular incisors did not have caries in these age cohorts. Caries-prone subjects had the shortest survival in all their teeth. The median longevity of all restorations was 11.7 years, with great variation between health centers and teeth. Because of the great variation between individual teeth, the tooth-specific approach seems appropriate in both caries epidemiology and material sciences. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Oral health of the young has been reported to be associated with the place of residence, due to differences in socio-economic status. The results of studies on the effect of fluoride in drinking water on caries prevalence have been contradictory. The main aim of our study was to investigate the geographical distribution of dental caries prevalence in Finland and analyse possible regional, associated factors. Oral health of 13,564 men born between 1990 and 1992 was screened using a method based on criteria of the World Health Organization for epidemiological studies by 15 calibrated dentists in 20/24 garrisons of the Finnish Defence Forces in 2011. Mean DMFT and DT values in provinces were calculated. Multilevel analysis was applied to the data using generalized linear mixed models and a logit link function. The binary outcome variable was the cariological treatment need (yes/no) and the garrison was treated as random effect. Mean DMFT and DT values varied significantly between provinces in Finland. Increased levels of fluoride in drinking water, Swedish as the main language in the municipality, and living in urban areas were protective factors against cariological treatment need. Dentist density did not affect caries prevalence. The geographical distribution of dental caries further supported estimates of the protective effects of high fluoride levels in drinking water, Swedish as the main language in the municipality, as well as living in urban areas. Effect of fluoride on caries prevalence still exists, and association with the socio-economic status was confirmed. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Metalloproteinases (MMPs) have been implicated with metabolism of collagen in physiological and pathological processes in human dentine. As bovine teeth have been used as a substitute for human teeth in laboratory analysis, this study evaluated the activity of MMP-2 and -9 in bovine versus human dentine. Bovine and human dentine fragments, from crowns and roots, were powderized. Protein extraction was performed by two protocols: a neutral extraction with guanidine-HCl/EDTA (pH 7.4) and an acidic extraction with citric acid (pH 2.3). Gelatinolytic activities of extracts were revealed by zymography. MMP-2 and -9 were detected in crown and root dentine from bovine and human teeth. Total activities of MMP-2 were 11.4 ± 2.2, 14.6 ± 2.0, 9.7 ± 1.2 and 12.4 ± 0.9 ng/ml for bovine root, human root, bovine crown and human crown dentine, respectively. Corresponding activities for MMP-9 were 14.9 ± 2.0, 15.3 ± 1.3, 15.4 ± 1.3 and 15.5 ± 1.3 ng/ml, respectively. Bovine dentine was found to be a reliable substrate for studies involving the activity of MMP-2 and -9. [ABSTRACT FROM AUTHOR]

It is known that some metal salts can inhibit matrix metalloproteinase (MMP) activity, but the effect of iron has not been tested yet. On the other hand, it has recently been suggested that MMP inhibition might influence dentine erosion. Based on this, the aims of this study were: (1) to test in vitro the effect of FeSO4 on MMP-2 and -9 activity, and (2) to evaluate in situ the effect of FeSO4 gel on dentine erosion. MMP-2 and -9 activities were analysed zymographically in buffers containing FeSO4 in concentrations ranging between 0.05 and 1.5 mmol/l or not. Volunteers (n = 10) wore devices containing bovine dentine blocks (n = 60) previously treated with the following gel treatments: FeSO4 (1 mmol/l FeSO4), F (NaF 1.23%; positive control) and placebo (negative control). The gels were applied once and removed after 1 min. Erosion was performed extraorally with Coca-Cola 4 times per day for 5 min over 5 days. Dentine wear was evaluated by profilometry. The data were analysed by Kruskal-Wallis and Dunn’s tests (p < 0.05). FeSO4 inhibited both MMP-2 (IC50 = 0.75 mmol/l) and MMP-9 (IC50 = 0.50 mmol/l) activities. In the in situexperiment, the mean wear (± SD) found for the F gel (0.79 ± 0.08 μm) was significantly reduced in more than 50% when compared to the placebo gel (1.77 ± 0.33 μm), but the FeSO4 gel completely inhibited the wear (0.05 ± 0.02 μm). Since FeSO4 was able to inhibit MMP in vitro, it is possible that the prevention of dentine wear by the FeSO4 gel in situ might be due to MMP inhibition, which should be investigated in further studies. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Aim To undertake a large-scale analysis of the expression profiles of native human pulp tissue and odontoblasts, and search for genes expressed only in odontoblasts. Methodology Microarray was performed to pooled pulp and odontoblasts of native human third molars and to pooled +/− TGF-β1 cultured pulps and odontoblasts (137 teeth). The repeatability of microarray analysis was estimated by comparing the experimental pulp samples with expression profiles of two pulp samples downloaded from the GEO database. The genes expressed only in the experimental pulp samples or in odontoblasts were divided into categories, and the expression of selected odontoblast-specific genes of extracellular matrix (ECM) organization and biogenesis category was confirmed with RT-PCR and Western blot. Results A 85.3% repeatability was observed between pulp microarrays, demonstrating the high reliability of the technique. Overall 1595 probe sets were positive only in pulp and 904 only in odontoblasts. Sixteen expressed sequence tags (ESTs), which represent transcribed sequences encoding possibly unknown genes, were detected only in odontoblasts; two consistently expressed in all odontoblast samples. Matrilin 4 (MATN4) was the only ECM biogenesis and organization related gene detected in odontoblasts but not in pulp by microarray and RT-PCR. MATN4 protein expression only in odontoblasts was confirmed by Western blot. Conclusions Pulp tissue and odontoblast gene expression profiling provides basic data for further, more detailed protein analysis. In addition, MATN4 and the two ESTs could serve as an odontoblast differentiation marker, e.g. in odontoblast stem cell research. [ABSTRACT FROM AUTHOR]

Aim: Candida albicans has been proposed to be a caries pathogen, but the evidence for its specific role is lacking. To be considered significant in caries progression, a marked amount of yeasts should be present in a lesion. The aim of the study was to investigate the presence of C. albicans in dentinal caries lesions. Materials and methods: To demonstrate the extension of caries and to identify the bacteria in a lesion, sections of 10 carious human teeth were stained with Gram and Giemsa stains. C. albicans was detected with periodic acid-Schiff (PAS) staining and by immunohistochemistry using a C. albicans-specific antibody 3H8. Thirty sections were used for each staining (in total 120 sections). Results: Extensive bacterial invasion and intensive staining by PAS occurred in all samples. However, with the C. albicans-specific antibody, only 30 (3.3%) sections stained weakly positive, with a few stained cells on the lesion surface. However, the positive identification of C. albicans, based on the morphology of the cells, was not possible. Conclusions: The results do not support the previous suggestion that C. albicans is important in the dentine caries pathology. In addition, because of its unspecific nature, PAS turned out to be an unsuitable method for detecting yeasts in carious tooth samples. [ABSTRACT FROM AUTHOR]

Background: Radiation therapy for head and neck tumour patients may lead to decreased salivary flow, oral mucosal lesions and increased caries experience. Salivary matrix metalloproteinases (MMPs) may participate in the pathogenesis of mucosal lesions and dentinal caries. The aims of this study were: (i) to assay the presence, molecular forms and proteolytic activity of MMP-8 (collagenase-2) and MMP-9 (gelatinase B) in the whole saliva of head and neck cancer patients having radiation therapy; (ii) to see whether salivary pH affects the activity of MMP-8 and MMP-9; and (iii) to find out the possible connection between MMP-8 and MMP-9 with the eruption of oral mucosal lesions during radiation therapy.Methods: The whole saliva samples of 39 head and neck cancer patients having radiation therapy were collected before, during and after radiation therapy, and saliva flow rate, pH, buffer capacity, Streptococcus mutans, Lactobacillus and Candida albicans were measured. Any oral mucosal lesions were examined during each visit. The levels of MMP-8 were measured by immunofluorometric assay (IFMA) and the presence of different MMP-8 forms was analysed using Western immunoblotting. The presence and molecular forms of MMP-9 were analyzed by gelatin zymography. MMP-9 capture activity assay was used to determine the APMA-activated MMP-9 activity (total) and the endogenously active MMP-9 (free activity).Results: Salivary flow rate, buffer capacity and pH decreased, and the levels of Lactobacilli increased significantly, during the first half of the radiation therapy. The endogenously activated salivary MMP-9 correlated with low salivary pH (P = 0.013). No connection was found between the oral mucosal lesions and salivary MMP-8 or MMP-9.Conclusions: In this study, salivary MMP-8 or MMP-9 did not correlate with the presence of radiation induced oral mucosal lesions, but the activation of MMP-9 may be dependent on pH. [ABSTRACT FROM AUTHOR]