Full text publication rates of research abstracts presented at the European Society of Endodontology (ESE) Congresses in the last 20 years.

AIM: To evaluate the full-text publication rates of scientific research abstracts presented at the European Society of Endodontology (ESE) Congresses held between 1993 and 2013 (a total of 11 occasions) and to determine factors associated with the manuscripts. METHODOLOGY: An electronic database search was conducted from January 2015 to December 2016 to identify full text English written publications of the research abstracts presented at the last 11 ESE Biennial Congresses from 1993 to 2013. For each occasion, research abstract information were retrieved from the International Endodontic Journal (IEJ) through the official website of the ESE and the following parameters for each abstract presentation were recorded: Year of presentation, first author's affiliation, geographic origin, and type of study. Following full-text article identification, additional information was recorded such as: Year and journal of publication, elapsed time until full publication and number of authors per presentation and publication. RESULTS: A total of 1165 research abstracts were presented, of which 401 (34.4%) were finally published as full-length articles. Overall 235 articles (58.6%) were published either in the International Endodontic Journal (IEJ, 35.7%) or Journal of Endodontics (JOE, 22.9%). The mean time between abstract presentation and full-text publication was 18.95 months. Munich (2001) had the highest publication rate (44%) whereas Lisbon (2013) had the highest number of published articles (77). Turkey was the country with the highest number of published abstracts (56). However, the Netherlands was the country with the highest number of publications related to the number of presentations (21/26) (80.7%). Differences in authorship between presentation and full publication were found in 179 (44.6%) articles. CONCLUSIONS: A substantial number of research abstracts presented at ESE congresses were not published in peer reviewed journals. Authors prefer to publish their research papers in international journals with high impact factor. This article is protected by copyright. All rights reserved.

Analysis of clinical studies related to apexification techniques.

AIM: The aim of this study was to gather all the clinical studies regarding apexification and artificial apical barrier techniques, point out the possible differences of the clinical procedures and investigate how these are changing over time. MATERIALS AND METHODS: An electronic search was carried out in PubMed, covering the period from March 1968 to July 2015. More articles were retrieved by hand-searching or by the reference section of the included articles. Specific criteria were set in order to determine the relevance of each study. RESULTS: One hundred and thirty eight articles were included, 53% of them concerned apexification with MTA plug. Long term apexification studies demonstrated 13% for a single change of the intracanal medicament and 85% for two or more. In 13% of the studies concerning artificial apical plug, the procedure included a single visit. Calcium hydroxide was left in the root canal for 3-12 months in 59% of the long term apexification studies, for 12-24 in 42% and for 24 months or more in 10%. CONCLUSION: Both techniques can lead to favourable clinical outcomes. There is a tendency for the artificial apical barrier apexification over the years, which usually includes the use of intracanal medicament for a short time.

A prospective study of the incidence of asymptomatic pulp necrosis following crown preparation.

AIM: To determine the incidence of asymptomatic pulp necrosis following crown preparation as well as the positive predictive value of the electric pulp testing. METHODOLOGY: A total of 120 teeth with healthy pulps scheduled to receive fixed crowns (experimental teeth) were included. Teeth were divided into two groups according to the preoperative crown condition (intact teeth and teeth with preoperative caries, restorations or crowns) and into four groups according to tooth type (maxillary anterior teeth, maxillary posterior teeth, mandibular anterior teeth and mandibular posterior teeth). Experimental and control teeth were submitted to electric pulp testing on three different occasions before treatment commencement (stage 0), at the impression making session (stage 1) and just before the final cementation of the crown (stage 2). Teeth that were considered to contain necrotic pulps were submitted to root canal treatment. Upon access, absence of bleeding was considered as a confirmation of pulp necrosis. Data were analysed using bivariate (chi-square) and multivariate analysis (logistic regression). All reported probability values (P-values) were based on two-sided tests and compared to a significance level of 5%. RESULTS: The overall incidence of pulp necrosis was 9%. Intact teeth had a significantly lower incidence of pulp necrosis (5%) compared with preoperatively structurally compromised teeth (13%) [(OR: 9.113, P = 0.035)]. No significant differences were found amongst the four groups with regard to tooth type (P = 0.923). The positive predictive value of the electric pulp testing was 1.00. CONCLUSIONS: The incidence of asymptomatic pulp necrosis of teeth following crown preparation is noteworthy. The presence of preoperative caries, restorations or crowns of experimental teeth correlated with a significantly higher incidence of pulp necrosis. Electric pulp testing remains a useful diagnostic instrument for determining the pulp condition.

Dental Stem Cells and their Applications in Dental Tissue Engineering.

Tooth loss or absence is a common condition that can be caused by various pathological circumstances. The replacement of the missing tooth is important for medical and aesthetic reasons. Recently, scientists focus on tooth tissue engineering, as a potential treatment, beyond the existing prosthetic methods. Tooth engineering is a promising new therapeutic approach that seeks to replace the missing tooth with a bioengineered one or to restore the damaged dental tissue. Its main tool is the stem cells that are seeded on the surface of biomaterials (scaffolds), in order to create a biocomplex. Several populations of mesenchymal stem cells are found in the tooth. These different cell types are categorized according to their location in the tooth and they demonstrate slightly different features. It appears that the dental stem cells isolated from the dental pulp and the periodontal ligament are the most powerful cells for tooth engineering. Additional research needs to be performed in order to address the problem of finding a suitable source of epithelial stem cells, which are important for the regeneration of the enamel. Nevertheless, the results of the existing studies are encouraging and strongly support the belief that tooth engineering can offer hope to people suffering from dental problems or tooth loss.

Frequency and distribution of root filled teeth and apical periodontitis in a Greek population.

AIM: To investigate the prevalence of root filled teeth and apical periodontitis (AP) in a Greek population. METHODOLOGY: A random sample of 320 patients who required full mouth periapical radiographic examination as a part of diagnostic and planning procedures were included. The age of the patients ranged from 16 to 77 years. A total of 7664 teeth were assessed and the frequency of root filled teeth and periapical status was recorded. Two observers evaluated the radiographs under standardized conditions. AP was defined as distinct periapical radiolucency or widening of the periodontal ligament space exceeding two times the normal width. Statistical evaluation of differences in proportions between groups was performed using random effects logistic regression models. RESULTS: The periapical status of 286 (3.7%) teeth was impossible to evaluate because of radiographic faults; these teeth were excluded from further analysis. A total of 1040 (13.6%) teeth had radiographic signs of AP and 680 (9.2%) teeth had been root filled. Of the root filled teeth, 408 (60.0%) had AP. There was no difference in the number of root filled teeth between males and females; the prevalence of root filled teeth increased with age. Significantly more molars (13.1%) and premolars (11.9%) than anterior teeth (5.8%) had been root filled (P < 0.001). The prevalence of AP was significantly higher (P < 0.001) in molars (23.9%) and premolars (14.0%) than anterior teeth (9.4%). CONCLUSIONS: The prevalence of AP and the frequency of root filled teeth with AP in this Greek population were higher than those found in many other European countries. The frequency of root filled teeth was comparable with findings in other epidemiological studies.

The influence of root-end resection and root-end cavity preparation on microleakage of root filled teeth in vitro.

AIM: To investigate in vitro the influence of root-end resection and root-end cavity preparation on leakage of root filled teeth. METHODOLOGY: The root canals of 48 roots, 16 mandibular premolars (G1), 16 mandibular incisors (G2) and 16 maxillary incisors (G3), 12 mm in length, were enlarged using a modified 'balanced force' technique and filled with gutta-percha and sealer using lateral compaction. After setting, leakage along the canal was measured using a fluid transport model. Root-end resection and root-end cavity preparation were then performed, leaving roots 10 mm in length with root fillings of 7 mm (groups R1, R2 and R3, respectively). Fluid transport was measured again along the remaining root fillings of all groups using the same experimental conditions. Results of leakage before and after root-end resection were analysed statistically using the Kruskal-Wallis and Wilcoxon tests. RESULTS: A total of 31% of the roots leaked before and 54% after root-end preparation; the difference was significantly different (P < 0.001). No significant differences were found either among groups G1, G2, G3 (P = 0.565) or among groups R1, R2, R3 (P =0.2628). Significant differences, however, were shown between groups G1-R1 (P = 0.0053), G2-R2 (P =0.0089) and G3-R3 (P = 0.0461). CONCLUSIONS: Root-end resection and root-end cavity preparation compromised the seal of 7 mm root fillings in all tooth groups. Increased leakage was recorded in the following order: mandibular incisors > mandibular premolars > maxillary incisors.

Dye penetration in dry and water-filled gaps along root fillings.

AIM: The aim of this study was to investigate the influence of hydration in voids along root fillings on methylene blue penetration. METHODOLOGY: A total of 80 human root canals were prepared using a step-back technique and filled with a zinc oxide based sealer and gutta-percha. Leakage along the fillings was measured by a transport fluid model and classified into three categories: gross leakage (GL), slight leakage (SL) and no leakage (NL). Specimens with NL and SL were immersed into methylene blue (MB) 2% for 24 h (group I). Specimens with GL which had wide gaps filled with water were randomly divided into two groups (II, III). Transport air was applied to remove water from gaps only in specimens of group III. All tested specimens from groups II and III were also immersed into MB 2% for 24 h. Each specimen was then split longitudinally and linear measurements of dye penetration were recorded. RESULTS: Group III (with dry gaps) showed significantly more dye penetration than group II. No significant difference was found between group I and group II. CONCLUSIONS: Methylene blue penetrates along root fillings more easily in dry gaps than in water-filled gaps.

Long-term seal provided by some root-end filling materials.

A tight and long-lasting seal of root-end fillings is of prime clinical importance. A hundred standard bovine root sections, each 3 mm high and with a central pulp lumen of 2.6 mm in diameter, were filled with five commonly used or potential root-end filling materials. At 24 h, or at 3, 6, or 12 months after filling, leakage along these filling materials was determined under a low headspace pressure of 10 kPa (0.1 atm) using a fluid transport model. During the first 3 months, the percentage of gross leakage (> 20 microliters day-1) increased noticeably for Tytin amalgam (from 20 to 100%) and Super-EBA (from 0 to 55%), whereas it decreased noticeably for mineral trioxide aggregate (MTA; from 55% to 0%). Thereafter, the increased leakage of amalgam and Super-EBA decreased with time, whereas the improved seal of MTA was maintained until the end of the experiment. At 3-, 6-, and 12-month time intervals, both glass ionomer cements (Fuji II and Hi Dense) and MTA showed less leakage than the conventional amalgam and Super-Eba, of which amalgam leaked more.

Decoloration of 1% methylene blue solution in contact with dental filling materials.

OBJECTIVES: Leakage studies have been performed frequently, since a tight seal provided by various dental fillings has been considered clinically important. The dye penetration experiment using a methylene blue solution as a tracer is one of the most common methods applied in these types of studies. The stability of the colour of methylene blue in contact with six dental filling materials was observed. METHODS: Silicon rubber tubes and human tooth roots of 10 mm in length and 1.5 mm inner diameter were filled with amalgam, calcium hydroxide, Cavit, Fuji II, mineral trioxide aggregate, or zinc oxide eugenol, 10 tubes or roots for each material. Groups of five tubes or roots filled with the same material were immersed in 0.8 ml 1% methylene blue dye solution. The optical density of the methylene blue solution before immersion and after 24, 48 and 72 h of immersion was measured in a spectrophotometer at 596 nm. RESULTS: The methylene blue solution was found to be decoloured over time by all the test materials (P < 0.01) except for Fuji II, in both silicone tubes and roots. At 24 h, the optical density value of methylene blue decreased by 73% for the Ca(OH)2/silicone group and 84% for the mineral trioxide aggregate/silicone group. CONCLUSION: Methylene blue is decoloured by some dental filling materials, which may result in unreliable results for these materials in dye leakage studies.

Microleakage along apical root fillings and cemented posts.

STATEMENT OF PROBLEM: Coronal leakage of endodontically treated teeth has been found to result in a high failure rate. PURPOSE: This study tested leakage along apical root fillings remaining after post space preparation and cemented posts in root canals. MATERIAL AND METHODS: A total of 120 human roots were used in the study and divided into six groups, 20 roots for each group. By using a modified fluid transport model, leakage (in microL/hr) along ParaPost dowels that were cemented in the coronal 7 mm of root canals with Fuji Duet, Ketac Cem, Panavia EX, or zinc phosphate cements was compared with that along the coronal 7 mm of conventional root canal fillings. Leakage along the apical 4 mm of root filling remaining after post space preparation was compared with that along the 11 mm root filling before post space preparation. RESULTS: More leakage was recorded along the apical 4 mm of root filling than along the 11 mm of original root filling (p = 0.0325). ParaPost dowels cemented with any test cement did not produce more leakage than the 7 mm coronal root filling (p = 0.2145). CONCLUSIONS: The apical 4 mm of root canal filling remaining after post space preparation leaks statistically significantly more than the original full-length root canal filling. The leakage created by removal of the coronal part of root canal filling during post space preparation may be compensated by the cemented posts.

Effect of sealer thickness on long-term sealing ability: a 2-year follow-up study.

Long-term sealing ability of root-canal sealer is of clinical importance. We compared the performance of five sealers and a dentine bonding agent, at thicknesses of 0.05 mm (thin layer) and 0.3 mm (thick layer), in 212 standard human root specimens, before and after storage in water for 2 years. Thick layers of Roth and Pulp Canal Sealer EWT (PCS-EWT) allowed more leakage than did thin layers (P = 0.0000, 0.0358 for Roth and PCS-EWT, respectively) whereas no significant difference was found between the thin and thick layers for AH26, Ketac-Endo, Sealapex and J&J Bonding Agent. The pooled results of the thin and thick layers, which have clinical relevance, showed that after storing the specimens in water for 2 years, AH26, Sealapex, Ketac-Endo and PCS-EWT leaked more than before storage in water (P = 0.0008, 0.0000, 0.0035, 0.0257 for AH26, Sealapex, Ketac-Endo and PCS-EWT respectively), and that J&J Bonding Agent allowed less leakage and PCS-EWT more leakage than the other four sealers (P = 0.0000).

Effect of calcium hydroxide dressing on seal of permanent root filling.

Low apical leakage along root fillings following an application of calcium hydroxide was reported in a few methylene blue dye penetration studies. It has been found recently that methylene blue is decolored by calcium hydroxide, indicating that the short penetration of methylene blue may not be due to a tight seal only. Of the 80 roots of human maxillary central incisors used in this study, 40 roots (group 1) received calcium hydroxide root canal dressing whereas another 40 roots (group 2) did not. All the roots were then obturated with gutta-percha and Tubli-Seal sealer. Leakage along 20 filled roots in each group was measured using a modified fluid transport model at 48 h, 2, 4, 8 and 16 weeks after obturation; whereas leakage of another 20 filled roots in each group was measured using dye penetration with 1% methylene blue. Using the fluid transport model, no significant difference was found between the two groups at any time interval (P = 0.4847, 0.3875, 0.9490, 0.4786, 0.9148 respectively after 48 h, 2, 4, 8 and 16 weeks); using the methylene blue penetration method, leakage in group 1 (with root canal dressing) was significantly less than that in group 2 (without root canal dressing) (P = 0.0374). The contradiction in results from the different models indicated that problems existed with the models.

In vitro study of the indirect action of calcium hydroxide on the anaerobic flora of the root canal.

The aim of this study was to evaluate in vitro a possible mechanism involved in the antimicrobial action of calcium hydroxide, namely absorption of carbon dioxide from the root canal. Twenty obligate and 20 facultative anaerobic bacteria isolated from infected root canals and identified to species level were used. For each bacterial species a standard concentration was achieved and 0.1 ml of the inoculum was spread on blood agar plates, which were consecutively incubated in an anaerobic chamber for 5-7 days. One experimental and one control group were studied: the experimental group included one plate with the bacterial species as well as one open plate containing 32 g calcium hydroxide paste at a mixing ratio of 6:4. Both plates were incubated in an anaerobic chamber for 72 h. The control group included only one plate containing the same bacterial species and was incubated under the same conditions. After a 72-h incubation, the number of the recovered bacteria were counted in both groups. Statistical analysis showed that the number of bacteria recovered from the control group was significantly lower than that of the experimental group, but no particular resistance of any bacterial species to calcium hydroxide could be detected. This finding strongly suggests that the ability of calcium hydroxide to absorb carbon dioxide may contribute to its antibacterial activity.

A novel rubber dam system for the simultaneous isolation of teeth and gingival tissues.

The present article introduces a rubber dam system developed for the simultaneous isolation of teeth and gingival tissues. The rubber dam device is fabricated from simple, easy-to-fine, and inexpensive materials, such as iron-core elastic tube, latex sheets, expanding screws, dental acrylic resin, and glue. Measurements of the dimensions of the maxillas and mandibles of 100 patients indicated that three prefabricated sizes of the device (small, medium, and large) can be applied in the majority of individuals.

Evaluation of the antimicrobial effectiveness of citric acid and sodium hypochlorite on the anaerobic flora of the infected root canal.

This study was designed to evaluate the antimicrobial effectiveness of 25% citric acid, compared with 2.5% sodium hypochlorite, after time intervals of 5, 15, 30 and 60 min. Anaerobic bacterial species were isolated from infected root canals and categorized according to Gram stain as Gram-positive cocci, Gram-negative cocci, Gram-positive rods and Gram-negative rods. The experimental method used was similar to that proposed by the German Society for Hygiene and Microbiology (DGHM) with slight modifications. Testing revealed that citric acid does demonstrate antimicrobial properties against anaerobic bacteria, especially against cocci, but it is less effective than 2.5% sodium hypochlorite.

In vitro evaluation of the effectiveness of calcium hydroxide and paramonochlorophenol on anaerobic bacteria from the root canal.

The effectiveness of calcium hydroxide and paramonochlorophenol (PMCP) was tested on anaerobic bacteria isolated from infected root canals, at time intervals 5, 15, 30 and 60 min. The experimental method used was similar to that proposed by the German Society of Hygiene and Microbiology (DGHM), with slight modifications. Testing revealed that calcium hydroxide was significantly more effective than PMCP against the total number of anaerobes. Additionally, it was proved to be quickly and highly effective against some microorganisms related to severe clinical symptoms, such as B. melaninogenicus and P. gingivalis, as well as against actinomyces species.

[Antibacterial action of calcium hydroxide as a root canal medicament]. / Antimikrobiake drase tou Ca(OH)2, otan ayto chresimopoieitai san pharmako egkleismou sten endodontike therapeia.

In this review article the antibacterial action of calcium hydroxide, as a root canal medicament is discussed. Initially its physicochemical principles as hydroscopic action, pH, gas absorption, ionism energy, etc., are described. Finally the antimicrobial effect of calcium hydroxide is correlated to the above properties.

[Root canal volume]. / Ypologismos tou ogkou ton rizikon solenon.

In this research we used 180 noncarious teeth, 15 from each kind, in which we cut the anatomic crown. After that we weighted the roots, each group separately, before and after the root canal obturation with the technique of lateral condensation of gutta percha and Grossman's sealer. The difference of the two weights represent the overload of the tooth after obturation. Then using mathematical rules we configured out the mean volume of the root canal of each group and the mean value of the diameter of the orifice of the canal of each group of teeth.