To assess the bond strength to dentin of an experimental adhesive and the proprietary resin cemen... more To assess the bond strength to dentin of an experimental adhesive and the proprietary resin cement used in different curing modes to lute ceramic disks of different thicknesses. Empress II disks (Ivoclar-Vivadent) were luted to dentin using XP BOND (Dentsply [XP]) in combination with the proprietary self-curing activator (SCA) and cement Calibra (Dentsply [C]). Curing of the adhesive was induced either by mixing with the activator (activator, groups 3 to 6) or by light irradiation for 20 s (group 2). The cement was either light cured for 40 s through the ceramic onlay (groups 1 to 5) or cured chemically (groups 6 and 7). Groups 2 and 4 were compared with group 1, in which Prime & Bond NT (Dentsply DeTrey) was tested as control. In groups 3 and 6, 2-mm-thick onlays were luted with XP+SCA, and the cement was light cured for 40 s or autocured for 5 min, respectively. These groups were compared with group 7, in which Syntac (Ivoclar Vivadent) was applied with C and, in order to reproduc...
Recently, several 'one-bottle' systems have been introduced for bonding into root canals.... more Recently, several 'one-bottle' systems have been introduced for bonding into root canals. This study evaluated the influence of two brushes used as carriers of a primer-adhesive solution in the formation of resin tags, adhesive lateral branches and hybrid layer when used to bond fiber posts. Twenty root canal treated teeth, extracted for periodontal reasons, were selected for this study. The samples were randomly divided into two groups of 10 samples each: Group 1: Microbrush + One Step + Dual Link resin cement; Group 2: One Step + Dual Link resin cement. The adhesive system and resin cement were used strictly following manufacturers' instructions. The priming-adhesive solution of the 'one-bottle' system was light-cured before placing the resin cement and the post. Twenty translucent fiber posts were used. Then, root samples were processed for SEM observation. The adhesive system showed resin dentin interdiffusion zone (RDIZ), resin tag and adhesive lateral branc...
This study evaluated the surface of different types of fiber posts after cutting and investigated... more This study evaluated the surface of different types of fiber posts after cutting and investigated whether different cutting procedures can affect the integrity of the posts. Six types of fiber posts were selected for this study (Carbon Fiber Posts, Quartz Fiber Posts, Aesthetic Posts, Aesthetic Plus Posts, Translucent Posts, Dentatus, FRC Postec Posts). Fifteen posts of each type were studied. All posts had a diameter of 1.2 to 1.4 mm and were between 14 and 16 mm long. Each group was divided into three subgroups (n = 5) according to cutting method: diamond bur, carborundum disk, or scissors. The samples were then processed for scanning electron microscopic investigation. At low magnifications, no microscopic differences were found among the samples of groups 1-4 and 6. Surfaces from group 5 were more irregular, but only when cut using rotating instruments. All groups showed differences between surfaces cut with scissors and those cut with either diamond bur or carborundum disk. Pos...
To verify with SEM the cement layer thickness and uniformity of resin-relined translucent fiber p... more To verify with SEM the cement layer thickness and uniformity of resin-relined translucent fiber posts (anatomic posts) and standard translucent fiber posts. On 20 extracted maxillary anterior teeth, the roots were endodontically treated and prepared for the insertion of a fiber post. Translucent fiber posts (DT) were luted with a dual-curing resin cement (Duo-Link) in 10 specimens (group 1) after the canal walls had been treated with the One-Step bonding system. In the other 10 specimens (group 2), experimental anatomic posts (Anatomic Post'n Core) were tested. To these posts, a layer of light-curing resin is added to allow for a pre-cementation relining of the post, aimed at improving its fit into the endodontic space. For luting, the same adhesive-resin cement combination of group 1 was used. All the roots were sectioned and prepared for SEM observations. At the 1-mm, 4.5-mm, and 8-mm level of each root, cement thickness was measured, and the presence of gaps or voids within t...
Restoration of root-treated teeth is routinely performed in clinical practice with a choice of th... more Restoration of root-treated teeth is routinely performed in clinical practice with a choice of therapeutic options, considering many factors to provide optimal mechanical properties, esthetics, and longevity. The aim of the present work was to present a preliminary clinical report on the use of fiber posts and direct resin composites for restoring root-treated teeth. Thirty-eight anterior and 62 posterior endodontically treated teeth were selected from 3 private prosthodontic offices. The protocol used included endodontic treatment, with translucent fiber posts (DT post) bonded to the post-space using a '1-bottle' adhesive (One-Step, Bisco) and a dual-cure resin cement (DuoLink, Bisco). Direct resin restorations were performed using a micro-hybrid resin composite (Gradia Direct, GC) and a layering technique. Both opaque dentin and enamel and translucent enamel shades were used. Patients were recalled after 6, 12, 24, and 30 months, and the restorations assessed according to ...
Potential intrinsic tetracycline staining of intraradicular dentin has been observed when BioPure... more Potential intrinsic tetracycline staining of intraradicular dentin has been observed when BioPure MTAD was employed as the final irrigant after initial rinsing with NaOCl. This study examined the effect of NaOCl-MTAD interaction on the antimicrobial substantivity of MTAD in dentin. Dentin cores previously irrigated with either MTAD, or in conjunction with 1.3% NaOCl as an initial irrigant were placed on blood agar plates inoculated with Escherichia faecalis at 10(5) cfu/ml. Dentin cores irrigated with 1.3% NaOCl only, and autoclaved dentin disks were used as the respective positive and negative controls. After anaerobic incubation, the mean diameter of bacterial inhibition zones formed around the MTAD group was significantly larger than the NaOCl/MTAD group, which, in turn, was not significantly different from the NaOCl positive control. Oxidation of MTAD by NaOCl resulted in the partial loss of antimicrobial substantivity in a manner similar to the peroxidation of tetracycline by r...
This study compared the effect of two drills and five cleaning regimens on post space debridement... more This study compared the effect of two drills and five cleaning regimens on post space debridement. One hundred extracted premolars were instrumented and obturated with warm vertical compaction of gutta percha. The teeth were divided into two groups according to the drill used to remove gutta percha/sealer and for post space preparation: a Largo drill (Largo; Dentsply, St Quentin en Yvelines, France) or a MTwo-PF drill (Sweden&Martina, Due Carrare, Padova, Italy). The following cleaning regimens were used: EDTA, ultrasonics, ultrasonics + EDTA, phosphoric acid, and distilled water. Scanning electron microscopic images of the post spaces were taken, and the presence of debris and of open dentin tubules were evaluated. The ultrasonics + EDTA, phosphoric acid, and EDTA groups were comparable in open tubules scores for both drills and in debris scores after the use of MTwo-PF (p > 0.05). The ultrasonics and control groups performed significantly worse (p < 0.05). The MTwo-PF drill ...
This study was designed to determine if the alloy composition shares an influence with the geomet... more This study was designed to determine if the alloy composition shares an influence with the geometric design on the physical behavior of nickel-titanium rotary endodontic instruments. ProTaper, HERO, and K3 files were selected. After sterilized and cleaning with alcohol, surface analysis was performed using energy dispersive spectroscopy. Measurements were performed on the active part and on the shank. SEM images of fractured instruments were also obtained and assessed. All three types of instruments were composed mainly of Nickel (54.3%, SD ± 0.8) and Titanium (45.2%, SD ± 0.9). SEM images revealed similar aspect with the presence of Kirkendall voids regularly distributed in the alloy. The results indicate that the difference in properties and behavior of these three endodontic rotary shaping instruments is solely related to the respective geometric characteristics of the instrument design.
Purpose: The aim of this study was to compare the bond strength obtained on root canal walls when... more Purpose: The aim of this study was to compare the bond strength obtained on root canal walls when using two different adhesive systems to bond a fiber reinforced composite (FRC) post inside a root canal and to evaluate the type of failure at the resin-dentine ...
The objective of this clinical report was to evaluate the effectiveness of a microbrush as a carr... more The objective of this clinical report was to evaluate the effectiveness of a microbrush as a carrier of priming-adhesive solution in formation of resin tags, adhesive lateral branches, and resin-dentin interdiffusion zone (RDIZ) when the brush was used to bond fiber posts under clinical conditions. Twenty endodontically treated teeth, already scheduled for extraction for endodontic or periodontal reasons, were selected for this study. The patients were informed, and their written consent was obtained. The samples were randomly divided into 2 groups of 10 samples each. In group 1, One-Step (Bisco, Schaumburg, Ill) was applied with a brush with Duo-Link resin cement (Bisco). In group 2, One-Step was applied with a microbrush with Duo-Link resin cement (Bisco). Use of the adhesive systems and resin cements was strictly according to manufacturers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; instructions. The priming-adhesive solution was light-cured before the dual resin cement and the post were placed. Twenty Aestheti-Plus posts (white quartz fiber posts; RTD, St. Egreve, France) were used. A week after application, the root samples were extracted and processed for SEM observations. Both adhesive systems showed RDIZ and resin tag and adhesive lateral branch formation. In Group 2 samples, RDIZ morphology was easily detectable and uniform along root canals. Also, resin tag formation was well represented in all thirds. In group 1 samples, resin tag formation at the apical third and RDIZ formation was less evident. Statistically significant differences were found among the two groups at the apical third. The microbrush permitted a more uniform RDIZ and resin tag formation along the entire length of the canal than did the standard brush. The microbrush can be routinely used for bonding fiber posts into root canal preparations.
The aim of the study was to assess cyclic fatigue resistance of reciprocating (Reciproc and WaveO... more The aim of the study was to assess cyclic fatigue resistance of reciprocating (Reciproc and WaveOne) and continuous rotating (ProTaper) nickel-titanium files after immersion in different irrigation solutions with or without surfactants during several short time periods. A total of 270 new Reciproc R25, WaveOne Primary, and ProTaper F2 files were tested. Instruments of each brand were divided into 1 control group (n = 10) formed by new files and 4 test groups (n = 20) formed by instruments dynamically immersed at 37°C for 16 mm in 5.25% sodium hypochlorite (NaOCl), Hypoclean (5.25% NaOCl with surfactant), 17% EDTA, or EDTA Plus (17% EDTA with surfactant). Each test group was subdivided into 2 subgroups (n = 10) on the basis of the time of dynamic immersion in the endodontic irrigant solution (45 seconds or 3 minutes). Resistance to cyclic fatigue was determined by recording time to fracture in a stainless steel artificial canal with a 60° angle of curvature and 5-mm radius of curvature. The fracture surface was examined by using scanning electron microscopy. Immersion in NaOCl did not reduce the cyclic fatigue of reciprocating or continuous nickel-titanium files. The 17% EDTA reduced the fatigue resistance of all instruments after 3 minutes. The immersion in irrigants with surfactants did not influence the cyclic fatigue of instruments except for Reciproc immersed in Hypoclean solution. EDTA immersion reduced the cyclic fatigue resistance of all instruments after 3 minutes. Addition of surfactants did not influence the cyclic fatigue of files except when added to NaOCl when it contacts Reciproc instruments.
The performance of both light-curing and dual-cured adhesive/luting systems (as control), when us... more The performance of both light-curing and dual-cured adhesive/luting systems (as control), when used in combination with translucent fibre posts, was evaluated by means of pull-out test and scanning electron microscopy (SEM ) observation. Forty root canal treated teeth were randomly divided into two groups of 20 specimens each. Group 1 light-curing system: Excite and Tetric Flow; Group 2 dual cured system: All Bond 2+RelyX ARC. Translucent, double taper fibre posts were used (2.1/1.4mm diameter). The teeth were stored in NaCl 0.9% solution at 37 degrees C. A week later, the pull-out test was carried out on all specimens. Ten tested specimens for each group and their corresponding posts were processed for SEM observation. Statistical analysis was performed applying one-way analysis of variance (ANOVA) followed by T-test as post-hoc comparison at a significance level set at p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05. There is no statistically significant difference (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;0.05) between the light-curing system group (275.2+/-58.9N) and the dual cured one (301.4+/-40.1N). SEM observations confirm a good bond between the dentine and the post whatever the curing method employed. Dual curing of the All Bond 2+RelyX ARC system seems to be the most appropriate method since it allows to cure even those areas which would not be otherwise reached by light. On the other hand, in apical areas, the incomplete curing of the Excite+Tetric Flow system could improve the post adaptation and allow the achievement of both an improved apical seal and a more even distribution of the stress along the canal walls.
This review aimed at summarizing the laboratory evidence collected on the retentive ability of ad... more This review aimed at summarizing the laboratory evidence collected on the retentive ability of adhesive posts since their introduction in dentistry. Data were searched in articles published or in press in peer-review journals listed in MEDLINE. Papers were retrieved through PubMed. To collect the evidence of interest, the following search terms were used: bond* AND fiber post AND in vitro; lut* AND fiber post AND in vitro; push-out AND fiber post; pull-out AND fiber post; microtensile AND fiber post. &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;Related Links&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; were also considered and articles cited in the initially retrieved papers were included if relevant. No time limit was given to the query. Seventy relevant papers were reviewed. The retentive ability of adhesive posts has been tested with the microtensile technique, post-pull-out and push-out tests. If small-sized specimens are obtained, such as in microtensile and thin-slice push-out, stress uniformity is favoured, local differences in bonding conditions can be discerned, and the number of teeth needed for the test can be reduced. Although adhesion to intraradicular dentin is more challenging to achieve than bonding to crown tissues, the post-retention achieved with current luting systems and techniques is adequate to ensure the clinical success of adhesive post-retained restorations. To enhance the bond at the post-core and post-cement interfaces, several chemical pre-treatments of the post-surface have been tested with positive results. Self-adhesive resin cements, recently proposed to simplify the post-luting procedure, should be investigated further with regard to durability.
To evaluate the ability of two luting procedures for bonding translucent fibre posts to form resi... more To evaluate the ability of two luting procedures for bonding translucent fibre posts to form resin tags, adhesive lateral branches, and resin dentine interdiffusion zones (RDIZ). Forty root filled teeth, extracted for periodontal reasons, were selected for the study. The teeth were randomly divided into four groups of 10 each. Group 1: One Step, light-cured (LC) 20 s + dual link resin cement (LC 20 s); group 2: One Step, not light-cured (NLC) + dual link resin cement (LC 30 s); group 3: One Step (NLC) + dual link resin cement (LC 60 s); group 4: One Step (NLC) + dual link resin cement (LC 90 sec). Forty translucent fibre posts (DT posts, RTD) were inserted. Then, root specimens were processed for scanning electron microscope (SEM) observations to assess the continuity of the RDIZ, the presence or absence of gaps and the density and morphology of resin tags using a four-step scale method. With all luting procedures the formation of a RDIZ occurred. However, the microscopic examination of adhesive interfaces revealed that the percentage of RDIZ was significantly higher in group 1 than in the other three groups (P &amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Group 4 had a higher percentage of RDIZ than group 3, which in turn exhibited a greater percentage than group 2, but these differences were not statistically significant (P &amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.05). Resin tag formation was evident in all the groups. The characteristic reverse cone shape of resin tags was always noted in the coronal and middle third of all groups, and in the apical third of group 1. In the apical third a shorter length and a less uniform appearance of resin tags were noted in groups 2, 3 and 4. In this laboratory study, when bonding a translucent fibre post into a root canal, the luting procedure including light curing of the adhesive solution before the placement of the cement was more satisfactory, from a SEM standpoint, than the procedure involving the simultaneous curing of adhesive and cement (one step procedure).
To compare the effectiveness of two Ni-Ti systems and hand files for removing gutta-percha and ... more To compare the effectiveness of two Ni-Ti systems and hand files for removing gutta-percha and sealer from root canals. The root canals of 60 single-rooted human teeth were prepared, filled with gutta-percha and sealer (Pulp Canal Sealer; SybronEndo, Orange, CA, USA). Specimens were then divided into three groups (n=20), and root filling material was removed using MTwo Retreatment Files (group 1); R-Endo (group 2); K-files and Gates-Glidden drills (group 3). After retreatment, the efficacy of each technique was assessed using radiographs that were later digitized and the images analysed using AutoCAD 2004. The percentage of residual gutta-percha was calculated for the whole canal as well as for the coronal, middle and apical thirds. Time required, apically extruded debris and the number of fractured instruments were also recorded. Data were statistically analysed using Kruskal-Wallis and Mann-Whitney U-tests. All instrumentation techniques left gutta-percha and sealer remnants inside the root canals. Ni-Ti systems were significantly faster (P &lt; 0.05) than the manual technique and significantly more effective (P &lt; 0.05) in removing gutta-percha particularly from the middle and apical thirds of the root canal. R-Endo instrumentation was significantly more effective (P &lt; 0.05) than MTwo retreatment files in removing gutta-percha from the middle and apical thirds. R-Endo instruments were associated with the least number of cases of apical extrusion. One MTwo instrument fractured. The Ni-Ti systems were more effective and faster than hand files, although all techniques left gutta-percha and sealer remnants on the root canals.
To assess the bond strength to dentin of an experimental adhesive and the proprietary resin cemen... more To assess the bond strength to dentin of an experimental adhesive and the proprietary resin cement used in different curing modes to lute ceramic disks of different thicknesses. Empress II disks (Ivoclar-Vivadent) were luted to dentin using XP BOND (Dentsply [XP]) in combination with the proprietary self-curing activator (SCA) and cement Calibra (Dentsply [C]). Curing of the adhesive was induced either by mixing with the activator (activator, groups 3 to 6) or by light irradiation for 20 s (group 2). The cement was either light cured for 40 s through the ceramic onlay (groups 1 to 5) or cured chemically (groups 6 and 7). Groups 2 and 4 were compared with group 1, in which Prime & Bond NT (Dentsply DeTrey) was tested as control. In groups 3 and 6, 2-mm-thick onlays were luted with XP+SCA, and the cement was light cured for 40 s or autocured for 5 min, respectively. These groups were compared with group 7, in which Syntac (Ivoclar Vivadent) was applied with C and, in order to reproduc...
Recently, several 'one-bottle' systems have been introduced for bonding into root canals.... more Recently, several 'one-bottle' systems have been introduced for bonding into root canals. This study evaluated the influence of two brushes used as carriers of a primer-adhesive solution in the formation of resin tags, adhesive lateral branches and hybrid layer when used to bond fiber posts. Twenty root canal treated teeth, extracted for periodontal reasons, were selected for this study. The samples were randomly divided into two groups of 10 samples each: Group 1: Microbrush + One Step + Dual Link resin cement; Group 2: One Step + Dual Link resin cement. The adhesive system and resin cement were used strictly following manufacturers' instructions. The priming-adhesive solution of the 'one-bottle' system was light-cured before placing the resin cement and the post. Twenty translucent fiber posts were used. Then, root samples were processed for SEM observation. The adhesive system showed resin dentin interdiffusion zone (RDIZ), resin tag and adhesive lateral branc...
This study evaluated the surface of different types of fiber posts after cutting and investigated... more This study evaluated the surface of different types of fiber posts after cutting and investigated whether different cutting procedures can affect the integrity of the posts. Six types of fiber posts were selected for this study (Carbon Fiber Posts, Quartz Fiber Posts, Aesthetic Posts, Aesthetic Plus Posts, Translucent Posts, Dentatus, FRC Postec Posts). Fifteen posts of each type were studied. All posts had a diameter of 1.2 to 1.4 mm and were between 14 and 16 mm long. Each group was divided into three subgroups (n = 5) according to cutting method: diamond bur, carborundum disk, or scissors. The samples were then processed for scanning electron microscopic investigation. At low magnifications, no microscopic differences were found among the samples of groups 1-4 and 6. Surfaces from group 5 were more irregular, but only when cut using rotating instruments. All groups showed differences between surfaces cut with scissors and those cut with either diamond bur or carborundum disk. Pos...
To verify with SEM the cement layer thickness and uniformity of resin-relined translucent fiber p... more To verify with SEM the cement layer thickness and uniformity of resin-relined translucent fiber posts (anatomic posts) and standard translucent fiber posts. On 20 extracted maxillary anterior teeth, the roots were endodontically treated and prepared for the insertion of a fiber post. Translucent fiber posts (DT) were luted with a dual-curing resin cement (Duo-Link) in 10 specimens (group 1) after the canal walls had been treated with the One-Step bonding system. In the other 10 specimens (group 2), experimental anatomic posts (Anatomic Post'n Core) were tested. To these posts, a layer of light-curing resin is added to allow for a pre-cementation relining of the post, aimed at improving its fit into the endodontic space. For luting, the same adhesive-resin cement combination of group 1 was used. All the roots were sectioned and prepared for SEM observations. At the 1-mm, 4.5-mm, and 8-mm level of each root, cement thickness was measured, and the presence of gaps or voids within t...
Restoration of root-treated teeth is routinely performed in clinical practice with a choice of th... more Restoration of root-treated teeth is routinely performed in clinical practice with a choice of therapeutic options, considering many factors to provide optimal mechanical properties, esthetics, and longevity. The aim of the present work was to present a preliminary clinical report on the use of fiber posts and direct resin composites for restoring root-treated teeth. Thirty-eight anterior and 62 posterior endodontically treated teeth were selected from 3 private prosthodontic offices. The protocol used included endodontic treatment, with translucent fiber posts (DT post) bonded to the post-space using a '1-bottle' adhesive (One-Step, Bisco) and a dual-cure resin cement (DuoLink, Bisco). Direct resin restorations were performed using a micro-hybrid resin composite (Gradia Direct, GC) and a layering technique. Both opaque dentin and enamel and translucent enamel shades were used. Patients were recalled after 6, 12, 24, and 30 months, and the restorations assessed according to ...
Potential intrinsic tetracycline staining of intraradicular dentin has been observed when BioPure... more Potential intrinsic tetracycline staining of intraradicular dentin has been observed when BioPure MTAD was employed as the final irrigant after initial rinsing with NaOCl. This study examined the effect of NaOCl-MTAD interaction on the antimicrobial substantivity of MTAD in dentin. Dentin cores previously irrigated with either MTAD, or in conjunction with 1.3% NaOCl as an initial irrigant were placed on blood agar plates inoculated with Escherichia faecalis at 10(5) cfu/ml. Dentin cores irrigated with 1.3% NaOCl only, and autoclaved dentin disks were used as the respective positive and negative controls. After anaerobic incubation, the mean diameter of bacterial inhibition zones formed around the MTAD group was significantly larger than the NaOCl/MTAD group, which, in turn, was not significantly different from the NaOCl positive control. Oxidation of MTAD by NaOCl resulted in the partial loss of antimicrobial substantivity in a manner similar to the peroxidation of tetracycline by r...
This study compared the effect of two drills and five cleaning regimens on post space debridement... more This study compared the effect of two drills and five cleaning regimens on post space debridement. One hundred extracted premolars were instrumented and obturated with warm vertical compaction of gutta percha. The teeth were divided into two groups according to the drill used to remove gutta percha/sealer and for post space preparation: a Largo drill (Largo; Dentsply, St Quentin en Yvelines, France) or a MTwo-PF drill (Sweden&Martina, Due Carrare, Padova, Italy). The following cleaning regimens were used: EDTA, ultrasonics, ultrasonics + EDTA, phosphoric acid, and distilled water. Scanning electron microscopic images of the post spaces were taken, and the presence of debris and of open dentin tubules were evaluated. The ultrasonics + EDTA, phosphoric acid, and EDTA groups were comparable in open tubules scores for both drills and in debris scores after the use of MTwo-PF (p > 0.05). The ultrasonics and control groups performed significantly worse (p < 0.05). The MTwo-PF drill ...
This study was designed to determine if the alloy composition shares an influence with the geomet... more This study was designed to determine if the alloy composition shares an influence with the geometric design on the physical behavior of nickel-titanium rotary endodontic instruments. ProTaper, HERO, and K3 files were selected. After sterilized and cleaning with alcohol, surface analysis was performed using energy dispersive spectroscopy. Measurements were performed on the active part and on the shank. SEM images of fractured instruments were also obtained and assessed. All three types of instruments were composed mainly of Nickel (54.3%, SD ± 0.8) and Titanium (45.2%, SD ± 0.9). SEM images revealed similar aspect with the presence of Kirkendall voids regularly distributed in the alloy. The results indicate that the difference in properties and behavior of these three endodontic rotary shaping instruments is solely related to the respective geometric characteristics of the instrument design.
Purpose: The aim of this study was to compare the bond strength obtained on root canal walls when... more Purpose: The aim of this study was to compare the bond strength obtained on root canal walls when using two different adhesive systems to bond a fiber reinforced composite (FRC) post inside a root canal and to evaluate the type of failure at the resin-dentine ...
The objective of this clinical report was to evaluate the effectiveness of a microbrush as a carr... more The objective of this clinical report was to evaluate the effectiveness of a microbrush as a carrier of priming-adhesive solution in formation of resin tags, adhesive lateral branches, and resin-dentin interdiffusion zone (RDIZ) when the brush was used to bond fiber posts under clinical conditions. Twenty endodontically treated teeth, already scheduled for extraction for endodontic or periodontal reasons, were selected for this study. The patients were informed, and their written consent was obtained. The samples were randomly divided into 2 groups of 10 samples each. In group 1, One-Step (Bisco, Schaumburg, Ill) was applied with a brush with Duo-Link resin cement (Bisco). In group 2, One-Step was applied with a microbrush with Duo-Link resin cement (Bisco). Use of the adhesive systems and resin cements was strictly according to manufacturers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; instructions. The priming-adhesive solution was light-cured before the dual resin cement and the post were placed. Twenty Aestheti-Plus posts (white quartz fiber posts; RTD, St. Egreve, France) were used. A week after application, the root samples were extracted and processed for SEM observations. Both adhesive systems showed RDIZ and resin tag and adhesive lateral branch formation. In Group 2 samples, RDIZ morphology was easily detectable and uniform along root canals. Also, resin tag formation was well represented in all thirds. In group 1 samples, resin tag formation at the apical third and RDIZ formation was less evident. Statistically significant differences were found among the two groups at the apical third. The microbrush permitted a more uniform RDIZ and resin tag formation along the entire length of the canal than did the standard brush. The microbrush can be routinely used for bonding fiber posts into root canal preparations.
The aim of the study was to assess cyclic fatigue resistance of reciprocating (Reciproc and WaveO... more The aim of the study was to assess cyclic fatigue resistance of reciprocating (Reciproc and WaveOne) and continuous rotating (ProTaper) nickel-titanium files after immersion in different irrigation solutions with or without surfactants during several short time periods. A total of 270 new Reciproc R25, WaveOne Primary, and ProTaper F2 files were tested. Instruments of each brand were divided into 1 control group (n = 10) formed by new files and 4 test groups (n = 20) formed by instruments dynamically immersed at 37°C for 16 mm in 5.25% sodium hypochlorite (NaOCl), Hypoclean (5.25% NaOCl with surfactant), 17% EDTA, or EDTA Plus (17% EDTA with surfactant). Each test group was subdivided into 2 subgroups (n = 10) on the basis of the time of dynamic immersion in the endodontic irrigant solution (45 seconds or 3 minutes). Resistance to cyclic fatigue was determined by recording time to fracture in a stainless steel artificial canal with a 60° angle of curvature and 5-mm radius of curvature. The fracture surface was examined by using scanning electron microscopy. Immersion in NaOCl did not reduce the cyclic fatigue of reciprocating or continuous nickel-titanium files. The 17% EDTA reduced the fatigue resistance of all instruments after 3 minutes. The immersion in irrigants with surfactants did not influence the cyclic fatigue of instruments except for Reciproc immersed in Hypoclean solution. EDTA immersion reduced the cyclic fatigue resistance of all instruments after 3 minutes. Addition of surfactants did not influence the cyclic fatigue of files except when added to NaOCl when it contacts Reciproc instruments.
The performance of both light-curing and dual-cured adhesive/luting systems (as control), when us... more The performance of both light-curing and dual-cured adhesive/luting systems (as control), when used in combination with translucent fibre posts, was evaluated by means of pull-out test and scanning electron microscopy (SEM ) observation. Forty root canal treated teeth were randomly divided into two groups of 20 specimens each. Group 1 light-curing system: Excite and Tetric Flow; Group 2 dual cured system: All Bond 2+RelyX ARC. Translucent, double taper fibre posts were used (2.1/1.4mm diameter). The teeth were stored in NaCl 0.9% solution at 37 degrees C. A week later, the pull-out test was carried out on all specimens. Ten tested specimens for each group and their corresponding posts were processed for SEM observation. Statistical analysis was performed applying one-way analysis of variance (ANOVA) followed by T-test as post-hoc comparison at a significance level set at p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05. There is no statistically significant difference (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;0.05) between the light-curing system group (275.2+/-58.9N) and the dual cured one (301.4+/-40.1N). SEM observations confirm a good bond between the dentine and the post whatever the curing method employed. Dual curing of the All Bond 2+RelyX ARC system seems to be the most appropriate method since it allows to cure even those areas which would not be otherwise reached by light. On the other hand, in apical areas, the incomplete curing of the Excite+Tetric Flow system could improve the post adaptation and allow the achievement of both an improved apical seal and a more even distribution of the stress along the canal walls.
This review aimed at summarizing the laboratory evidence collected on the retentive ability of ad... more This review aimed at summarizing the laboratory evidence collected on the retentive ability of adhesive posts since their introduction in dentistry. Data were searched in articles published or in press in peer-review journals listed in MEDLINE. Papers were retrieved through PubMed. To collect the evidence of interest, the following search terms were used: bond* AND fiber post AND in vitro; lut* AND fiber post AND in vitro; push-out AND fiber post; pull-out AND fiber post; microtensile AND fiber post. &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;Related Links&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; were also considered and articles cited in the initially retrieved papers were included if relevant. No time limit was given to the query. Seventy relevant papers were reviewed. The retentive ability of adhesive posts has been tested with the microtensile technique, post-pull-out and push-out tests. If small-sized specimens are obtained, such as in microtensile and thin-slice push-out, stress uniformity is favoured, local differences in bonding conditions can be discerned, and the number of teeth needed for the test can be reduced. Although adhesion to intraradicular dentin is more challenging to achieve than bonding to crown tissues, the post-retention achieved with current luting systems and techniques is adequate to ensure the clinical success of adhesive post-retained restorations. To enhance the bond at the post-core and post-cement interfaces, several chemical pre-treatments of the post-surface have been tested with positive results. Self-adhesive resin cements, recently proposed to simplify the post-luting procedure, should be investigated further with regard to durability.
To evaluate the ability of two luting procedures for bonding translucent fibre posts to form resi... more To evaluate the ability of two luting procedures for bonding translucent fibre posts to form resin tags, adhesive lateral branches, and resin dentine interdiffusion zones (RDIZ). Forty root filled teeth, extracted for periodontal reasons, were selected for the study. The teeth were randomly divided into four groups of 10 each. Group 1: One Step, light-cured (LC) 20 s + dual link resin cement (LC 20 s); group 2: One Step, not light-cured (NLC) + dual link resin cement (LC 30 s); group 3: One Step (NLC) + dual link resin cement (LC 60 s); group 4: One Step (NLC) + dual link resin cement (LC 90 sec). Forty translucent fibre posts (DT posts, RTD) were inserted. Then, root specimens were processed for scanning electron microscope (SEM) observations to assess the continuity of the RDIZ, the presence or absence of gaps and the density and morphology of resin tags using a four-step scale method. With all luting procedures the formation of a RDIZ occurred. However, the microscopic examination of adhesive interfaces revealed that the percentage of RDIZ was significantly higher in group 1 than in the other three groups (P &amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.05). Group 4 had a higher percentage of RDIZ than group 3, which in turn exhibited a greater percentage than group 2, but these differences were not statistically significant (P &amp;amp;amp;amp;amp;amp;amp;amp;gt; 0.05). Resin tag formation was evident in all the groups. The characteristic reverse cone shape of resin tags was always noted in the coronal and middle third of all groups, and in the apical third of group 1. In the apical third a shorter length and a less uniform appearance of resin tags were noted in groups 2, 3 and 4. In this laboratory study, when bonding a translucent fibre post into a root canal, the luting procedure including light curing of the adhesive solution before the placement of the cement was more satisfactory, from a SEM standpoint, than the procedure involving the simultaneous curing of adhesive and cement (one step procedure).
To compare the effectiveness of two Ni-Ti systems and hand files for removing gutta-percha and ... more To compare the effectiveness of two Ni-Ti systems and hand files for removing gutta-percha and sealer from root canals. The root canals of 60 single-rooted human teeth were prepared, filled with gutta-percha and sealer (Pulp Canal Sealer; SybronEndo, Orange, CA, USA). Specimens were then divided into three groups (n=20), and root filling material was removed using MTwo Retreatment Files (group 1); R-Endo (group 2); K-files and Gates-Glidden drills (group 3). After retreatment, the efficacy of each technique was assessed using radiographs that were later digitized and the images analysed using AutoCAD 2004. The percentage of residual gutta-percha was calculated for the whole canal as well as for the coronal, middle and apical thirds. Time required, apically extruded debris and the number of fractured instruments were also recorded. Data were statistically analysed using Kruskal-Wallis and Mann-Whitney U-tests. All instrumentation techniques left gutta-percha and sealer remnants inside the root canals. Ni-Ti systems were significantly faster (P &lt; 0.05) than the manual technique and significantly more effective (P &lt; 0.05) in removing gutta-percha particularly from the middle and apical thirds of the root canal. R-Endo instrumentation was significantly more effective (P &lt; 0.05) than MTwo retreatment files in removing gutta-percha from the middle and apical thirds. R-Endo instruments were associated with the least number of cases of apical extrusion. One MTwo instrument fractured. The Ni-Ti systems were more effective and faster than hand files, although all techniques left gutta-percha and sealer remnants on the root canals.
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Papers by Simone Grandini