Pantelis Kouros - Academia.edu (original) (raw)

Papers by Pantelis Kouros

Journal of Esthetic and Restorative Dentistry, 2022

Oral health & preventive dentistry, 2020

PURPOSE To evaluate the effect of pre-treatment air abrasion of surfaces using bioactive glass 45... more PURPOSE To evaluate the effect of pre-treatment air abrasion of surfaces using bioactive glass 45S5 on the progression of erosion in bovine enamel induced by a common soft drink. MATERIALS AND METHODS Twelve intact bovine incisors were selected and 24 enamel samples were prepared and randomly assigned to two groups (n = 12): 1. control group, no anti-erosive treatment; 2. experimental group: samples were air abraded with bioglass 45S5 before the erosive challenge. The enamel samples were submitted to erosive cycling using a common soft drink. Enamel surface loss was evaluated using optical profilometry; surface microhardness and roughness changes were determined using Vickers method and Vertical Scanning Interferometry, respectively. In addition, SEM observations and EDS analysis were performed to detect any alterations in surface morphology and mineral content. The data were statistically analysed using one-way ANOVA and Tukey's post-hoc test at a significance level of α = 0.05...

Invasive cervical resorption is a pathologic process leading to progressive and usually destructi... more Invasive cervical resorption is a pathologic process leading to progressive and usually destructive loss of tooth structure. The pathogenic mechanism is not completely understood and the diagnosis may be challenging. The aim of this article is to present an unusual case of bilateral presence of invasive cervical resorption lesions in maxillary central incisors and to discuss the treatment procedures using a novel repair material. The management of the present case was carried out in three phases. The first stage of the treatment aimed at curetting the active tissue from the resorption cavity and restoring the defect with the novel calcium silicate-based cement (Biodentine, Septodont). In the maxillary left central incisor it was not possible to remove the resorptive tissue without exposing the pulp, and therefore root canal treatment was performed. At the second phase, a full-thickness flap was raised in order to expose and repair the defect that was extending subgingivally. At the ...

European Journal of Oral Sciences, 2020

Evaluation of photopolymerization efficacy and temperature rise of a composite resin using a blue... more Evaluation of photopolymerization efficacy and temperature rise of a composite resin using a blue diode laser (445 nm).

$Research paper thumbnail of Digital subtraction radiography in detection of vertical root fractures: accuracy evaluation for root canal filling, fracture orientation and width variables. An ex-vivo study$

Clinical Oral Investigations, 2020

Objective Ex-vivo evaluation of the detectability of vertical root fractures (VRFs) using digital... more Objective Ex-vivo evaluation of the detectability of vertical root fractures (VRFs) using digital subtraction radiography (DSR) and conventional digital periapical radiography (CDPR); investigation of the effect of root canal filling, x-ray angulation, and thickness of the VRF in the diagnostic accuracy. Materials and methods Sixty root canals were mechanically prepared and radiographed either with a gutta-percha root canal filling or without, at 0 o and ± 10 o. VRFs were introduced with a universal testing machine. The width and angulation of the fracture line with the radiographic beam were calculated. DSR was performed comparing radiographs obtained prior to and after the VRF induction. Five examiners evaluated the resultant images and analysis was performed using receiver operator characteristic (ROC) statistics and binary logistic regression tests. Results No significant differences in sensitivity, specificity, and the areas under the ROC curves (AUC) between the CDPR and DSR were detected (p > 0.05), except for root canal filled teeth where the AUC for DSR was higher (p < 0.05). Using DSR, a VRF was 1.3 times more likely to be diagnosed [95% confidence intervals (CI): 1.045-1.59; p = 0.018]. A correct diagnosis was 2.399 times more likely to occur in non-filled teeth regardless of the radiographic technique (95% CI 1.940-2.965; p = 0). The regression coefficients were positive for width and negative for angle. Conclusions DSR showed a better diagnostic accuracy of VRFs compared with CDPR, in single root canal filled teeth. The angulation, the width, and the presence of a root canal filling affected the diagnostic potential. Clinical relevance DSR is a cost-and time-effective imaging technique that could contribute in early diagnosis of VRFs.

Journal of Conservative Dentistry, 2018

Objectives: The aim of this study is to investigate the influence of the composite material and s... more Objectives: The aim of this study is to investigate the influence of the composite material and surface treatment to the bond strength when repairing an aged composite surface with new composite. Materials and Methods: One hundred and sixty resin blocks of methacrylate composite and silorane composite prepared and aged in artificial saliva for 6 months. Specimens treated either with a diamond bur (DB) or air abrasion (AA), conditioned with orthophosphoric acid (OA) or sodium hypochloride (SH) and repaired with methacrylate or silorane composite using the corresponding adhesive system. Repaired composites underwent thermocycling fatigue (×5000), and bond strength was measured at shear. Results: Methacrylate achieved the highest bond strengths as repair material, in all combinations (26.54-55.56 MPa). Silorane only reached 8.12 MPa when repairing silorane treated with DB and OA. For all other treatment combinations repairing with silorane led to pretest failures. The most susceptible to repair composites/surface treatment combination is when repairing methacrylate treated with AA and SH and methacrylate composite (55.56 MPa). Conclusions: Silorane composites are not suitable to be used when repairing an old composite restoration. The repair material is the most critical factor, while aged surface treatment has only a minor influence to the shear bond strength.

European Journal of Dentistry, 2012

ABSTRACTObjective: The shear bond strength of adhesives applied to dentin was investigated after ... more ABSTRACTObjective: The shear bond strength of adhesives applied to dentin was investigated after irradiation with an erbium-doped yttrium aluminum garnet (Er:YAG) laser.Methods: Superficial and deep dentin specimens from human molars were treated either with carbide bur or an Er:YAG laser. Two etch and rinse adhesives (Single Bond and XP Bond) and two self-etch adhesives (Prompt L-Pop and Xeno III) were employed to bond the composite. Shear bond strength (SBS) was determined after storage in water for 24 h using a universal testing machine with a crosshead speed of 0.5 mm/min. Failure patterns and modes were analyzed and evaluated using a stereomicroscope. In addition, samples were processed for Scanning Electron Microscopy SEM evaluation. A linear mixed model was used, and pairwise comparisons were made using the Bonferroni test.Results: Results showed significant differences between the levels of dentin treatment (p=.01) in carbide bur-cut dentin and lased dentin, as well as signi...

Lasers in Dental Science, 2019

Purpose This clinical trial aims to evaluate in vivo the efficacy of a fluoride gel, a low-level ... more Purpose This clinical trial aims to evaluate in vivo the efficacy of a fluoride gel, a low-level laser (LLL), and a resin varnish at the treatment of dentin hypersensitivity (DH). Treatments assessed for their effectiveness, immediate analgesia, and duration of desensitization. Material and methods A total of 78 patients (one tooth per patient) with a clinical diagnosis of dentin hypersensitivity were included in this clinical trial. Dentin sensitivity in response to an air blast stimulus was assessed, and a Numeric Rating Scale (NRS) for pain from 0 to 10 was chosen to quantify pain at baseline and 15 min, 1 month, and 3 months after the first application. Patients were randomly divided into three groups. In the first group (treatment A, 26 patients), a fluoride gel (Calmodent Professional, Intermed, Greece) was applied. In the second group (treatment B, 26 patients), teeth were irradiated by a 670-nm InGaAlP continuous wave, red diode laser (MED-701, Lasotronic, Switzerland) with an output power of 180 mW, energy of 5.4 J, and irradiation time of 30 s. In the third group (treatment C, 26 patients), a resin varnish with giomer technology (PRG Barrier Coat, Shofu, Japan) was applied. Results The main analysis of the results was done with a linear mixed model (algorithm MIXED, IBM Statistics SPSS 21.0), while pairwise comparisons were conducted with the Bonferroni method. The statistical significance for all tests was set at p < 0.05. The main effects of time and group were found to be statistically significant. The time × group interaction effect was also statistically significant, and finally, a significant reduction (p < 0.05) of DH was recorded in all groups, compared with baseline. Conclusion All three treatments offered satisfactory and prolonged results.

Operative Dentistry, 2018

SUMMARY Aims: To evaluate the effect of two composite restorative techniques (direct bulk fill vs... more SUMMARY Aims: To evaluate the effect of two composite restorative techniques (direct bulk fill vs indirect CAD/CAM) on the fracture resistance and mode of fracture of extended mesio-occlusal-distal (MOD) cavity preparations. Methods: Fifty-one sound human mandibular third molars were divided into three groups (n=17). Extended bucco-lingual MOD cavities were prepared. Teeth in group 1 were restored with a bulk-fill resin composite (Filtek Bulk-Fill Posterior Restorative), teeth in group 2 were restored with composite computer-aided design/computer-aided manufacturing (CAD/CAM) inlays (Lava Ultimate), and teeth in group 3 served as control and remained intact. All specimens were submitted to thermocycling, and a fracture resistance test was performed using a Universal testing machine (0.5 mm/min). Mode of fracture was classified into five types. One-way analysis of variance and the Duncan test were used to analyze the fracture load data at a significance level of α = 0.05. A chi-squar...

Balkan Journal of Dental Medicine, 2017

SummaryThe aim of this in vitro study was to compare the degree of microleakage on enamel and den... more SummaryThe aim of this in vitro study was to compare the degree of microleakage on enamel and dentin margins of class V cavities prepared with either a high-speed drill or an Er,Cr:YSGG laser (2780 nm) and to associate their use with a beveling method for the margin.Sixty bovine incisors were randomly distributed into three groups. Group 1 (G1) cavities were laser prepared and bur beveled, group 2 (G2) cavities were bur prepared and beveled, while cavities of group 3 (G3) were laser prepared and beveled. Cavities were restored with selective enamel etching, using the same bonding agent and nano-hybrid resin composite for all groups. After thermocycling, microleakage was assessed using a methylene blue dye penetration method.Statistical analysis (Mann-Whitney, Kruskal-Wallis and post-hoc Dunn’s multiple comparison tests) demonstrated significantly higher microleakage for dentin compared to enamel margins in G1. Enamel margin microleakage was found to be significantly higher at G3 com...

European Journal of Dentistry, 2013

Objective: To clinically investigate the antibacterial effects of a commercially available self-e... more Objective: To clinically investigate the antibacterial effects of a commercially available self-etch 12-methacryloyloxy- dodecylpyridinium bromide (MDPB)-containing adhesive system in comparison with its respective non-MDPB-containing adhesive and to evaluate the pulp responses when in use on human teeth. Materials and Methods: Sixty-two viable human teeth scheduled for extraction were used. Class V cavities were prepared on the buccal surfaces of the teeth and filled with the tested materials (Protect Bond/Clearfil AP-X, SE Bond/Clearfil AP-X and Dycal/Ketac Fill Plus) as a control group, according to manufacturer′s recommendations. Randomly divided to two groups teeth remained intra-orally for 4 and 8 weeks. After extraction, teeth were decalcified, sectioned and stained using the Mayer′s hematoxylin and eosin, and modified Brown-Brenn′s technique. Pulp responses were evaluated microscopically under a microscope and remaining dentine thickness measured under a stereomicroscope. Re...

Objective: The inhibitory effect of chlorexidine to endogenous matrix metaloproteinases, has been... more Objective: The inhibitory effect of chlorexidine to endogenous matrix metaloproteinases, has been recently attracted attention in studying the dynamics of dentin bonding agents. The aim of this study was to evaluate the effects of 2% digluconate chlorexidine, to the shear bond strength of two new adhesive systems. Method: The following self-etch systems were tested: a water-acetone-ethanol self-etch adhesive (Optibond All-In-One, Kerr) and a a solvent free self-etch adhesive (Bond 1 SF, Pentron Clinical). Eighty human teeth were sectioned longitudinally and polished with 600 grit SiC paper. The adhesive area was isolated with a cylindrical Teflon mold 3-4 mm. Half of the specimens for each self-etch system were teated with 2% digluconate chlorexidine before self-etch systems were applied. All specimens were thermocycled and stressed at a rate of 0.5mm/min, half of them 24 hours after the application and half of them 3 months later. Failure patterns were analyzed using stereomicrosco...

European journal of dentistry, 2014

The objective was to investigate the way that various surface treatments could influence the bond... more The objective was to investigate the way that various surface treatments could influence the bond strength of the repair of methacrylate (MC) and silorane (SIL) composites. A total of 160 MC and SIL cylindrical specimens were polymerized and aged in artificial saliva solution for 7 days. Depending on the following surface treatment (diamond bur or air abrasion), and the conditioning procedure (orthophosphoric acid or sodium hypochlorite), 16 groups were formed and repaired either with MC, either with SIL composite. Repaired specimens were subjected to an additional aging procedure in artificial saliva for 7 days, followed by thermo-cycling and then stressed in shear at a rate of 0.5 mm/min until failure. Failure patterns were analyzed using stereomicroscope and scanning electron microscopy. MC composite showed statistically significant higher bond strength both as a base or repair material than SIL (P < 0.001). Statistically significant differences were not observed, when grindin...

American journal of dentistry, 2011

(1) To measure the temperature rise during long-time irradiation needed to lute adhesive indirect... more (1) To measure the temperature rise during long-time irradiation needed to lute adhesive indirect restorations, with one halogen and five LED high-power lamps, in a simulated oral environment, and (2) to propose a technique to reduce heat. Temperature within the pulp chamber of an extracted human molar in a 35 degrees C water bath, before and after restoration with a ceramic onlay, was continuously recorded during 3 x 120 seconds of irradiation for different curing regimens, with and without cooling by compressed air, water and water spray. Temperature rise in a thermo-insulated well was also measured during 120 seconds of irradiation with LEDemetron II and TuTu. Maximal temperature rise of 6.2 degrees C/7.7 degrees C on intact/onlay restored tooth was found after 3 x 120 seconds of irradiation. Compressed air application reduced the temperature by 4 degrees C for LEDemetron II, while water spray increased the temperature by 15.1 degrees C for TuTu. Temperature decreased with irradiation distance, except for LEDemetron II. Air was heated up to 65 degrees C after 120 seconds of irradiation in an insulated well with TuTu.

ABSTRACT Objectives: The majority of clinical trials concerning pulp reactions when resin materia... more ABSTRACT Objectives: The majority of clinical trials concerning pulp reactions when resin materials are placed in deep cavities, performed in young pulps, with a high regenerative capacity. Everyday clinical practice however, regards teeth with questionable pulp condition. This is a clinical study of pulp condition in periodontal teeth, after application of an antibacterial adhesive system, in deep cavities. Methods: Forty-six viable, caries free, human teeth scheduled for extraction due to periodontal reasons from patients 40-50 years old were used. The protocol was conducted according to guidelines for research in humans in Aristotle University of Thessaloniki. Class V cavities (approximately 2.50 mm wide, 3.00 mm long) were prepared on the buccal surface of teeth. Cavities were randomly divided in two groups and filled as follows: group A: Protect Bond/ Clearfil AP-X and group B: Dycal/Ketac Fill Plus. Teeth were extracted 4 or 8 weeks postoperatively and prepared for histological assessment. All sections were stained either with Mayer's hematoxylin-eosin stain or using modified Brown-Brenn's technique. The criteria used to assess the connective tissue reactions were: inflammatory cell response, tissue disorganization, tertiary dentin formation and remaining dentin thickness. Statistical analysis was performed by SPSS 15.0 using 2-way ANOVA, Kruskal Wallis test and Mann Whitney test (p=0.05). Results: Bacteria infiltration of the pulp was not present in any specimen. In few specimens bacteria were found along the cavity walls or within the cut dentinal tubules. No severe inflammation or severe tissue disorganization was demonstrated. Tests showed no statistical significant differences regarding to inflammatory cell response and tissue disorganization among groups. Hard tissue formation was not seen in any teeth. Conclusions: It may be concluded that placing a resin adhesive with antibacterial properties in deep cavities with close proximity to pulp cavity is a safe procedure.

Brazilian Journal of Oral Sciences, 2014

Aim: To compare the shear bond strength (SBS) of a solvent free self-etch adhesive with solvent c... more Aim: To compare the shear bond strength (SBS) of a solvent free self-etch adhesive with solvent containing adhesives. Methods: Forty-five human teeth were sectioned longitudinally to expose superficial dentin and substrates polished with 600-grit SiC paper. The adhesive area was isolated with a cylindrical Teflon mold 3x4 mm. Fifteen specimens were prepared for each material. Were evaluated a solvent free self-etch adhesive (Bond 1 SF), an ethanol self-etch adhesive (Futurabond M), and a water-acetone-ethanol self-etch adhesive (Optibond All-In-One). All specimens were subjected to an aging procedure by thermo-cycling (5000 cycles). Thirty-six specimens were stressed in shear at a rate of 0.5mm/min. Mean data values were analyzed statistically using the Welch robust analysis of variance and the Games-Howell statistic. Failure patterns were analyzed using stereomicroscope and scanning electron microscopy (SEM). Additional more dentin specimens were prepared for SEM. Results: The Bond 1 SF showed the statistically significant lowest SBS to dentin (Welch statistic p<0.001). Failures for Bond 1 SF were mainly adhesive failures with partial cohesive failures in the adhesive resin, while for Futurabond M and Optibond All-In-One were mainly mixed. SEM findings confirm the results. Conclusions: Eliminating solvents from self-etch adhesive systems may decrease the bonding strength to dentin.

Lasers in Medical Science, 2013

The aim of this study was to investigate the shear bond strength of two adhesive systems to laser... more The aim of this study was to investigate the shear bond strength of two adhesive systems to laser-irradiated dentin compared with their shear bond strength to bur-cut dentin as well as to evaluate the influence of composition and type of dental materials on shear bond strength. Thirty-two dentin specimens prepared from human third molars were divided into two groups and conditioned either with an Er:YAG laser machine or with a carbide bur. Two different adhesive systems (Silorane System Adhesive and Single Bond) were evaluated in the present study. After light curing of the adhesives, a Teflon mold was placed over the ring with the dentin sample and filled with the composite resins Filtek Silorane and Filtek Z250 combined with the appropriate adhesive systems. This procedure resulted in 32 cylindrical specimens (3 mm in diameter, 4 mm in height) being bonded to the dentin. The specimens were stored for 24 h at 37 °C in water and then were thermocycled. Shear bond strength testing was conducted by means of a universal testing machine and failure patterns were analyzed under a stereomicroscope. Two specimens of each fracture failure mode were randomly selected for SEM evaluation. Filtek Silorane present no statistically significant difference in shear bond strength compared with Filtek Z250, regardless of dentin treatment (p > 0.05). Additionally, the self-etching Silorane Adhesive System exhibited as good adhesive values as etch-and-rinse Single Bond, independently on dentinal substrate (p > 0.05). Specimens prepared by Er:YAG laser appear as receptive to adhesive procedures as conventional carbide bur-cut specimens (p > 0.05).