G. Plotino - Academia.edu (original) (raw)

Papers by G. Plotino

Medical Science Monitor, 2014

The purpose of the present study was to introduce a new device specifically designed to evaluate ... more The purpose of the present study was to introduce a new device specifically designed to evaluate the cutting efficiency of mechanically driven endodontic instruments.

International Endodontic Journal, 2006

Plotino G, Grande NM, Sorci E, Malagnino VA, Somma F. A comparison of cyclic fatigue between used... more Plotino G, Grande NM, Sorci E, Malagnino VA, Somma F. A comparison of cyclic fatigue between used and new Mtwo Ni-Ti rotary instruments. International Endodontic Journal, 39, 716-723, 2006.

Journal of Endodontics, 2007

The aims of this study were to compare Resilon (Resilon

Journal of Endodontics, 2011

Introduction: The purpose of this study was to assess the resistance to cyclic fatigue of three n... more Introduction: The purpose of this study was to assess the resistance to cyclic fatigue of three nickel-titanium (NiTi) files after the immersion in sodium hypochlorite (NaOCl) solution in conditions similar to those used in clinical practice. Methods: A total of 150 new Twisted Files (SybronEndo, Orange, CA), Revo S SU files (Micro Mega, Besancon, France), and Mtwo files (Sweden and Martina, Padova, Italy), size 25.06, were tested. Fifty files of the same brand were randomly assigned to five groups (n = 10) and submitted to the following immersion protocol in 5% NaOCl at 37 C for 16 mm: no immersion (control), 5 minutes statically, 1 minute statically, 5 minutes dynamically (300 rpm/min), and 1 minute dynamically. Resistance to cyclic fatigue was determined by counting the numbers of cycles to failure in a 60 curve with a 5-mm radius. Data were analyzed by two-way analyses of variance. Results: Resistance to cyclic fatigue of the same NiTi file was not significantly affected by immersion in NaOCl (P > .05). The Twisted File showed a higher resistance in all groups than Revo S SU (P < .001). The comparison between the same groups of Twisted Files and Mtwo files or between Mtwo and Revo S files did not show significant differences (P > .05) except for two cases: group 2 of the Twisted Files and Mtwo files and group 5 of the Mtwo and Revo S SU files (P < .05). Conclusions: Static or dynamic immersion in NaOCl for 1 minute or 5 minutes did not reduce the cyclic fatigue resistance of NiTi significantly. However, the type of instrument influences cyclic fatigue resistance. In our study, Twisted Files were more resistant followed by Mtwo and Revo S SU files. (J Endod 2011;37:1139-1142

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2007

Objective. The objective of this study was to evaluate the influence of the moment when reduced p... more Objective. The objective of this study was to evaluate the influence of the moment when reduced pressure is applied on dye penetration patterns. Study design. Nine hundred and sixty glass capillary tubes of different inner diameter (0.3 mm and 0.8 mm), divided into 48 groups, were submerged into dye in 3 different positions (horizontally, opening upwards, and opening downwards) under different vacuum conditions (passive, 5 kPa, 35 kPa, 70 kPa reduced pressure). When reduced pressure was applied half of the groups were submerged into dye before and half of the groups after the application of reduced pressure. Linear dye penetration was measured. Univariate analysis was performed with Mann-Whitney U test and Kruskal-Wallis test to select variables to be included in the regression model. A multiple logistic regression analysis with backward elimination was performed to assess the influence of different covariates on linear dye penetration. Results. The multivariate linear regression showed that the moment of vacuuming had the greatest positive effect on linear dye penetration value (␤ ϭ 10.6, P Ͻ .0001). Also the level of pressure reduction had a positive effect on the outcome variable (␤ ϭ 0.2, P Ͻ .0001) while the vertical positioning of the tubes has negatively affected the outcome variable both for the open end upside (␤ ϭ Ϫ1.01, P ϭ .024) and the open end downside (␤ ϭ Ϫ1.05, P ϭ .019). Diameter of the tubes (P ϭ .442) and immersion time (P ϭ .727) had no effect on the outcome of linear dye penetration. Conclusions. Even minimum air pressure reduction applied before immersion of the specimens allowed the dye to extensively penetrate the voids. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;103:289-94) a Professor,

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2010

Objective. The aim of this study was to investigate the influence of the shape of 3 different art... more Objective. The aim of this study was to investigate the influence of the shape of 3 different artificial canals on the trajectory followed by different nickel-titanium rotary instruments. Study design. Ten ProFile and Mtwo instruments, tip sizes 20 and 25, taper .06, were tested in 3 simulated root canals with an angle of curvature of 60°and radius of curvature of 5 mm but with different shapes. Geometric analysis of the trajectory that each instrument followed inside the 3 different artificial canals was performed on digital images, determining 3 parameters: angle and radius of the curvature and the position of the center of the curvature. Mean values were then calculated for each instrument size in all of the artificial canals. Data were analysed using 1-way analysis of variance, Holm t test, and Student t test to determine any statistical difference (P Ͻ .05). Results. In all instrument sizes, a statistically significant difference was noted among the artificial canals for the radius and angle of curvature. No statistically significant difference was noted between instruments of the same size for the radius and angle of curvature and the position of the center of the curve when measured in the canal constructed on the dimension of the instruments. Conclusions. Different instruments follow different trajectories in artificial canals constructed with the same parameters of curvature but different shapes, depending on their different bending properties. All of the instruments respected the established parameters of curvature only when the artificial canal is designed on the dimension of the instruments.

Journal of Dentistry, 2009

Posts are primarily used to connect the root portion of endodontically treated teeth to the build... more Posts are primarily used to connect the root portion of endodontically treated teeth to the build-up material placed on the coronal portion of the teeth. 1-3 A post may not be needed if an endodontically treated tooth that requires a crown, or must be restored with an intracoronal restoration, has a sufficient amount of remaining dentin to retain the restoration. Prefabricated and cast metal posts have been traditionally used for the restoration of endodontically treated teeth, but more recently preformed fiber-reinforced root canal posts have made inroads as an alternative to metal posts. 6,7 FRC posts have demonstrated mechanical properties close to that of root canal dentin 8-11 and aim to restore the dentin-root complex using materials with matching mechanical properties, to improve the clinical performance of the restored tooth. Clinical prospective and retrospective studies on the use of FRC posts have reported encouraging results during short to medium clinical use. One of the disadvantages associated with the use of preformed posts is the need to adapt the root canal to the j o u r n a l o f d e n t i s t r y 3 7 ( 2 0 0 9 ) 3 8 3 -3 8 9

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2007

To determine whether the shaping of oval-shaped root canals using 2 different preparation techniq... more To determine whether the shaping of oval-shaped root canals using 2 different preparation techniques resulted in significant morphologic differences. Study design. Forty lower premolars with oval-shaped root canals were divided into group A, instrumented with the Anatomic Endodontic Technology (AET) system, and group B, treated with ProTaper instruments. A modified Bramante technique was used to analyze changes in root canal diameters (⌬D), changes in surface area (⌬A), and the change in buccolingual and mesiodistal ratio (⌬R). The data were subjected to a Student t test at a significance level of P Ͻ 0.05. Results. Statistically significant differences were found between the 2 groups at coronal and middle levels. There was no statistically significant difference at the apical level. Conclusions. The 2 techniques produced a significant difference in the ultimate shape of the coronal and middle portions of oval-shaped root canals, with the AET system removing more tooth structure at these levels. However, no differences were observed at the apical third.

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2008

Objective. The aims of this in vitro study were to measure root and canal diameters, root and can... more Objective. The aims of this in vitro study were to measure root and canal diameters, root and canal diameter ratios, mean taper of the root canal and of each root canal section, and radicular wall thickness at different levels in premolars with long oval root canals. Study design. Thirty human premolars, with single long oval canals were selected for this study. The specimens were analyzed with micro-computerized tomography. The cross-sections corresponding to 1, 2, 3, 4, 5, 7, 9, 11, and 13 mm from the radiologic apex were analyzed to measure the mesiodistal (MD) and buccolingual (BL) diameters of the canals and the thickness of the root and the walls. The BL/MD ratios of the canal (⌬C) and the root (⌬R) diameters were calculated, as was as the mean taper in both a BL and an MD dimension. Multiple logistic regression analyses were performed with a level of significance of P ϭ .05. Results. At all levels of analysis, the BL diameter was greater than the MD diameter for both the canal and the root. Generally, ⌬C and ⌬R increased coronally. Buccal and lingual wall thicknesses were greater than mesial and distal at all levels. Canal diameters at 1 mm from the apex were Ͼ0.30 mm in the shorter-oval diameter and Ͼ0.40 mm in the longer-oval diameter. In all root segments the BL taper was greater than the MD taper.

International Endodontic Journal, 2006

Plotino G, Grande NM, Brigante L, Lesti B, Somma F. Ex vivo accuracy of three electronic apex loc... more Plotino G, Grande NM, Brigante L, Lesti B, Somma F. Ex vivo accuracy of three electronic apex locators: Root ZX, Elements Diagnostic Unit and Apex Locator and ProPex.

International Endodontic Journal, 2008

Plotino G, Grande NM, Pameijer CH, Somma F. Influence of surface remodelling using burs on the ma... more Plotino G, Grande NM, Pameijer CH, Somma F. Influence of surface remodelling using burs on the macro and micro surface morphology of anatomically formed fibre posts. International Journal, 41, 345-355, 2008. Aim To evaluate the effect of modifying preformed fibre-reinforced composite (FRC) endodontic posts on their surface morphology and to determine how this procedure affects the integrity of the posts. Summary Surfaces of 10 preformed glass-fibre posts (group 1) and carbon-fibre posts (group 2) were compared with those of individually formed glass-fibre posts (group 3). Ten FRC posts were modelled in order to give them a shape as close as possible to the anatomy of oval root canals. Starting from a preformed cylindrical fibre post 2.5 mm in diameter, it was modelled in such a way as to passively occupy the entire post-space length, using a cast previously created as a guide. Microscopic analyses (optical stereomicroscope and scanning electron microscope) of the post surfaces revealed similar features in all three groups. All posts had regular surfaces after cutting with a diamond bur. Smear layer mainly attributable to the cutting procedures covered the cut surface of some specimens. In conclusion, modulation of a fibre post using a diamondcoated bur did not show a loss of integrity of the post. Key learning points • Because of the importance of micromechanical retention, the surface integrity of fibre posts may be important for adhesion between post and composite resin.

Introduction: Fractured rotary nickel-titanium (NiTi) instruments have been classified into those... more Introduction: Fractured rotary nickel-titanium (NiTi) instruments have been classified into those that fail as a result of cyclic flexural fatigue or torsional failure or a combination of both. Clinically, NiTi rotary instruments are subjected to both torsional load and cyclic fatigue, and ongoing research aims to clarify the relative contributions of both factors to instrument separation. Methods: To date, there is no specification or international standard to test cyclic fatigue resistance of endodontic rotary instruments. As a consequence, several devices and methods have been used to investigate in vitro cyclic fatigue fracture resistance of NiTi rotary endodontic instruments. In nearly all studies reported in the endodontic literature, the rotating instrument was either confined in a glass or metal tube, in a grooved block-and-rod assembly, or in a sloped metal block. Results: There has been no mention of the ''fit'' of the instrument in the tube or groove. As the instrument is likely to be fitting loosely, the description of the radius of curvature in those studies is likely to be overstated (ie, the file was actually bent less severely than reported, adding a variability in the amount of flexural stress). Conclusions: This review analyzed several devices that have been used in endodontic literature for cyclic fatigue testing and found that differences in the methodology affected the fatigue behavior of rotary instruments and, consequently, the outcome of these studies. An international standard for cyclic fatigue testing of NiTi rotary instruments is required to ensure uniformity of methodology and comparable results. (

Journal of endodontics, 2007

During the past few decades endodontic treatment has benefited from the development of new techni... more During the past few decades endodontic treatment has benefited from the development of new techniques and equipment, which have improved outcome and predictability. Important attributes such as the operating microscope and ultrasonics (US) have found indispensable applications in a number of dental procedures in periodontology, to a much lesser extent in restorative dentistry, while being very prominently used in endodontics. US in endodontics has enhanced the quality of treatment and represents an important adjunct in the treatment of difficult cases. Since its introduction, US has become increasingly more useful in applications such as gaining access to canal openings, cleaning and shaping, obturation of root canals, removal of intracanal materials and obstructions, and endodontic surgery. This comprehensive review of the literature aims at presenting the numerous uses of US in clinical endodontics and emphasizes the broad applications in a modern-day endodontic practice.

Journal of Endodontics, 2008

The aim of this study was to compare the effectiveness of the Mtwo R (Sweden & Martina, Padova, I... more The aim of this study was to compare the effectiveness of the Mtwo R (Sweden & Martina, Padova, Italy), ProTaper retreatment files (Dentsply-Maillefer, Ballaigues, Switzerland), and a Hedström manual technique in the removal of three different filling materials (gutta-percha, Resilon [Resilon Research LLC, Madison, CT], and EndoRez [Ultradent Products Inc, South Jordan, UT]) during retreatment. Ninety single-rooted straight premolars were instrumented and randomly divided into 9 groups of 10 teeth each (n ϭ 10) with regards to filling material and instrument used. For all roots, the following data were recorded: procedural errors, time of retreatment, apically extruded material, canal wall cleanliness through optical stereomicroscopy (OSM), and scanning electron microscopy (SEM). A linear regression analysis and three logistic regression analyses were performed to assess the level of significance set at p ϭ 0.05. The results indicated that the overall regression models were statistically significant. The Mtwo R, ProTaper retreatment files, and Resilon filling material had a positive impact in reducing the time for retreatment. Both ProTaper retreatment files and Mtwo R showed a greater extrusion of debris. For both OSM and SEM logistic regression models, the root canal apical third had the greatest impact on the score values. EndoRez filling material resulted in cleaner root canal walls using OSM analysis, whereas Resilon filling material and both enginedriven NiTi rotary techniques resulted in less clean root canal walls according to SEM analysis. In conclusion, all instruments left remnants of filling material and debris on the root canal walls irrespective of the root filling material used. Both the engine-driven NiTi rotary systems proved to be safe and fast devices for the removal of endodontic filling material. (J Endod 2008;34:466 -469)

International Endodontic Journal, 2006

Grande NM, Plotino G, Pecci R, Bedini R, Malagnino VA, Somma F. Cyclic fatigue resistance and thr... more Grande NM, Plotino G, Pecci R, Bedini R, Malagnino VA, Somma F. Cyclic fatigue resistance and three-dimensional analysis of instruments from two nickel-titanium rotary systems.

Dental Materials, 2007

ObjectivesTo evaluate the flexural modulus and flexural strength of different types of endodontic... more ObjectivesTo evaluate the flexural modulus and flexural strength of different types of endodontic post in comparison with human root dentin.

Journal of Endodontics, 2012

Introduction: The purpose of this study was to evaluate the effect of autoclave sterilization on ... more Introduction: The purpose of this study was to evaluate the effect of autoclave sterilization on cyclic fatigue resistance of rotary endodontic instruments made of traditional and new nickel-titanium (NiTi) alloys. Methods: Four NiTi rotary endodontic instruments of the same size (tip diameter 0.40 mm and constant .04 taper) were selected: K3, Mtwo, Vortex, and K3 XF prototypes. Each group was then divided into 2 subgroups, unsterilized instruments and sterilized instruments. The sterilized instruments were subjected to 10 cycles of autoclave sterilization. Twelve files from each different subgroup were tested for cyclic fatigue resistance. Means and standard deviations of number of cycles to failure (NCF) and fragment length of the fractured tip were calculated for each group, and data were statistically analyzed (P < .05). Results: Comparing the results between unsterilized and sterilized instruments for each type of file, differences were statistically significant (P < .05) only between sterilized and unsterilized K3XF files (762 versus 651 NCF). The other instruments did not show significant differences (P > .05) in the mean NCF as a result of sterilization cycles (K3, 424 versus 439 NCF; Mtwo, 409 versus 419 NCF; Vortex, 454 versus 480 NCF). Comparing the results among the different groups, K3 XF (either sterilized or not) showed a mean NCF significantly higher than all other files (P < .05). Conclusions: Repeated cycles of autoclave sterilization do not seem to influence the mechanical properties of NiTi endodontic instruments except for the K3 XF prototypes of rotary instruments that demonstrated a significant increase of cyclic fatigue resistance. (J Endod 2012;38:222-225)

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2009

Objective. The objective of this study was to investigate the trajectory of NiTi rotary instrumen... more Objective. The objective of this study was to investigate the trajectory of NiTi rotary instruments of the same size but different design in an artificial root canal manufactured for cyclic fatigue test. Study design. Eight groups of instruments with tip size 25, 0.06 taper with different design were tested in a simulated root canal with an angle of curvature of 60 degrees and radius of curvature of 5 mm milled in a stainless steel block with a tapered shape corresponding to the dimensions of the instruments tested. Geometric analysis of the trajectory that each instrument followed inside the artificial canal was performed on digital images, determining 3 parameters: angle and radius of the curvature and the position of the center of the curvature. Mean values were then calculated for each group. Data were analyzed using 1-way ANOVA and Holm t test to determine any statistical difference (P Ͻ .05).

Journal of Endodontics, 2008

Tooth discoloration varies in etiology, appearance, localization, severity, and adhesion to tooth... more Tooth discoloration varies in etiology, appearance, localization, severity, and adhesion to tooth structure. It can be defined as being extrinsic or intrinsic on the basis of localization and etiology. In this review of the literature, various causes of tooth discoloration, different bleaching materials, and their applications to endodontically treated teeth have been described. In the walking bleach technique the root filling should be completed first, and a cervical seal must be established. The bleaching agent should be changed every 3-7 days. The thermocatalytic technique involves placement of a bleaching agent in the pulp chamber followed by heat application. At the end of each visit the bleaching agent is left in the tooth so that it can function as a walking bleach until the next visit. External bleaching of endodontically treated teeth with an in-office technique requires a high concentration gel. It might be a supplement to the walking bleach technique, if the results are not satisfactory after 3-4 visits. These treatments require a bonded temporary filling or a bonded resin composite to seal the access cavity. There is a deficiency of evidence-based science in the literature that addresses the prognosis of bleached nonvital teeth. Therefore, it is important to always be aware of the possible complications and risks that are associated with the different bleaching techniques. (J Endod 2008; 34:394 -407)

Medical Science Monitor, 2014

The purpose of the present study was to introduce a new device specifically designed to evaluate ... more The purpose of the present study was to introduce a new device specifically designed to evaluate the cutting efficiency of mechanically driven endodontic instruments.

International Endodontic Journal, 2006

Plotino G, Grande NM, Sorci E, Malagnino VA, Somma F. A comparison of cyclic fatigue between used... more Plotino G, Grande NM, Sorci E, Malagnino VA, Somma F. A comparison of cyclic fatigue between used and new Mtwo Ni-Ti rotary instruments. International Endodontic Journal, 39, 716-723, 2006.

Journal of Endodontics, 2007

The aims of this study were to compare Resilon (Resilon

Journal of Endodontics, 2011

Introduction: The purpose of this study was to assess the resistance to cyclic fatigue of three n... more Introduction: The purpose of this study was to assess the resistance to cyclic fatigue of three nickel-titanium (NiTi) files after the immersion in sodium hypochlorite (NaOCl) solution in conditions similar to those used in clinical practice. Methods: A total of 150 new Twisted Files (SybronEndo, Orange, CA), Revo S SU files (Micro Mega, Besancon, France), and Mtwo files (Sweden and Martina, Padova, Italy), size 25.06, were tested. Fifty files of the same brand were randomly assigned to five groups (n = 10) and submitted to the following immersion protocol in 5% NaOCl at 37 C for 16 mm: no immersion (control), 5 minutes statically, 1 minute statically, 5 minutes dynamically (300 rpm/min), and 1 minute dynamically. Resistance to cyclic fatigue was determined by counting the numbers of cycles to failure in a 60 curve with a 5-mm radius. Data were analyzed by two-way analyses of variance. Results: Resistance to cyclic fatigue of the same NiTi file was not significantly affected by immersion in NaOCl (P > .05). The Twisted File showed a higher resistance in all groups than Revo S SU (P < .001). The comparison between the same groups of Twisted Files and Mtwo files or between Mtwo and Revo S files did not show significant differences (P > .05) except for two cases: group 2 of the Twisted Files and Mtwo files and group 5 of the Mtwo and Revo S SU files (P < .05). Conclusions: Static or dynamic immersion in NaOCl for 1 minute or 5 minutes did not reduce the cyclic fatigue resistance of NiTi significantly. However, the type of instrument influences cyclic fatigue resistance. In our study, Twisted Files were more resistant followed by Mtwo and Revo S SU files. (J Endod 2011;37:1139-1142

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2007

Objective. The objective of this study was to evaluate the influence of the moment when reduced p... more Objective. The objective of this study was to evaluate the influence of the moment when reduced pressure is applied on dye penetration patterns. Study design. Nine hundred and sixty glass capillary tubes of different inner diameter (0.3 mm and 0.8 mm), divided into 48 groups, were submerged into dye in 3 different positions (horizontally, opening upwards, and opening downwards) under different vacuum conditions (passive, 5 kPa, 35 kPa, 70 kPa reduced pressure). When reduced pressure was applied half of the groups were submerged into dye before and half of the groups after the application of reduced pressure. Linear dye penetration was measured. Univariate analysis was performed with Mann-Whitney U test and Kruskal-Wallis test to select variables to be included in the regression model. A multiple logistic regression analysis with backward elimination was performed to assess the influence of different covariates on linear dye penetration. Results. The multivariate linear regression showed that the moment of vacuuming had the greatest positive effect on linear dye penetration value (␤ ϭ 10.6, P Ͻ .0001). Also the level of pressure reduction had a positive effect on the outcome variable (␤ ϭ 0.2, P Ͻ .0001) while the vertical positioning of the tubes has negatively affected the outcome variable both for the open end upside (␤ ϭ Ϫ1.01, P ϭ .024) and the open end downside (␤ ϭ Ϫ1.05, P ϭ .019). Diameter of the tubes (P ϭ .442) and immersion time (P ϭ .727) had no effect on the outcome of linear dye penetration. Conclusions. Even minimum air pressure reduction applied before immersion of the specimens allowed the dye to extensively penetrate the voids. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2007;103:289-94) a Professor,

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2010

Objective. The aim of this study was to investigate the influence of the shape of 3 different art... more Objective. The aim of this study was to investigate the influence of the shape of 3 different artificial canals on the trajectory followed by different nickel-titanium rotary instruments. Study design. Ten ProFile and Mtwo instruments, tip sizes 20 and 25, taper .06, were tested in 3 simulated root canals with an angle of curvature of 60°and radius of curvature of 5 mm but with different shapes. Geometric analysis of the trajectory that each instrument followed inside the 3 different artificial canals was performed on digital images, determining 3 parameters: angle and radius of the curvature and the position of the center of the curvature. Mean values were then calculated for each instrument size in all of the artificial canals. Data were analysed using 1-way analysis of variance, Holm t test, and Student t test to determine any statistical difference (P Ͻ .05). Results. In all instrument sizes, a statistically significant difference was noted among the artificial canals for the radius and angle of curvature. No statistically significant difference was noted between instruments of the same size for the radius and angle of curvature and the position of the center of the curve when measured in the canal constructed on the dimension of the instruments. Conclusions. Different instruments follow different trajectories in artificial canals constructed with the same parameters of curvature but different shapes, depending on their different bending properties. All of the instruments respected the established parameters of curvature only when the artificial canal is designed on the dimension of the instruments.

Journal of Dentistry, 2009

Posts are primarily used to connect the root portion of endodontically treated teeth to the build... more Posts are primarily used to connect the root portion of endodontically treated teeth to the build-up material placed on the coronal portion of the teeth. 1-3 A post may not be needed if an endodontically treated tooth that requires a crown, or must be restored with an intracoronal restoration, has a sufficient amount of remaining dentin to retain the restoration. Prefabricated and cast metal posts have been traditionally used for the restoration of endodontically treated teeth, but more recently preformed fiber-reinforced root canal posts have made inroads as an alternative to metal posts. 6,7 FRC posts have demonstrated mechanical properties close to that of root canal dentin 8-11 and aim to restore the dentin-root complex using materials with matching mechanical properties, to improve the clinical performance of the restored tooth. Clinical prospective and retrospective studies on the use of FRC posts have reported encouraging results during short to medium clinical use. One of the disadvantages associated with the use of preformed posts is the need to adapt the root canal to the j o u r n a l o f d e n t i s t r y 3 7 ( 2 0 0 9 ) 3 8 3 -3 8 9

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2007

To determine whether the shaping of oval-shaped root canals using 2 different preparation techniq... more To determine whether the shaping of oval-shaped root canals using 2 different preparation techniques resulted in significant morphologic differences. Study design. Forty lower premolars with oval-shaped root canals were divided into group A, instrumented with the Anatomic Endodontic Technology (AET) system, and group B, treated with ProTaper instruments. A modified Bramante technique was used to analyze changes in root canal diameters (⌬D), changes in surface area (⌬A), and the change in buccolingual and mesiodistal ratio (⌬R). The data were subjected to a Student t test at a significance level of P Ͻ 0.05. Results. Statistically significant differences were found between the 2 groups at coronal and middle levels. There was no statistically significant difference at the apical level. Conclusions. The 2 techniques produced a significant difference in the ultimate shape of the coronal and middle portions of oval-shaped root canals, with the AET system removing more tooth structure at these levels. However, no differences were observed at the apical third.

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2008

Objective. The aims of this in vitro study were to measure root and canal diameters, root and can... more Objective. The aims of this in vitro study were to measure root and canal diameters, root and canal diameter ratios, mean taper of the root canal and of each root canal section, and radicular wall thickness at different levels in premolars with long oval root canals. Study design. Thirty human premolars, with single long oval canals were selected for this study. The specimens were analyzed with micro-computerized tomography. The cross-sections corresponding to 1, 2, 3, 4, 5, 7, 9, 11, and 13 mm from the radiologic apex were analyzed to measure the mesiodistal (MD) and buccolingual (BL) diameters of the canals and the thickness of the root and the walls. The BL/MD ratios of the canal (⌬C) and the root (⌬R) diameters were calculated, as was as the mean taper in both a BL and an MD dimension. Multiple logistic regression analyses were performed with a level of significance of P ϭ .05. Results. At all levels of analysis, the BL diameter was greater than the MD diameter for both the canal and the root. Generally, ⌬C and ⌬R increased coronally. Buccal and lingual wall thicknesses were greater than mesial and distal at all levels. Canal diameters at 1 mm from the apex were Ͼ0.30 mm in the shorter-oval diameter and Ͼ0.40 mm in the longer-oval diameter. In all root segments the BL taper was greater than the MD taper.

International Endodontic Journal, 2006

Plotino G, Grande NM, Brigante L, Lesti B, Somma F. Ex vivo accuracy of three electronic apex loc... more Plotino G, Grande NM, Brigante L, Lesti B, Somma F. Ex vivo accuracy of three electronic apex locators: Root ZX, Elements Diagnostic Unit and Apex Locator and ProPex.

International Endodontic Journal, 2008

Plotino G, Grande NM, Pameijer CH, Somma F. Influence of surface remodelling using burs on the ma... more Plotino G, Grande NM, Pameijer CH, Somma F. Influence of surface remodelling using burs on the macro and micro surface morphology of anatomically formed fibre posts. International Journal, 41, 345-355, 2008. Aim To evaluate the effect of modifying preformed fibre-reinforced composite (FRC) endodontic posts on their surface morphology and to determine how this procedure affects the integrity of the posts. Summary Surfaces of 10 preformed glass-fibre posts (group 1) and carbon-fibre posts (group 2) were compared with those of individually formed glass-fibre posts (group 3). Ten FRC posts were modelled in order to give them a shape as close as possible to the anatomy of oval root canals. Starting from a preformed cylindrical fibre post 2.5 mm in diameter, it was modelled in such a way as to passively occupy the entire post-space length, using a cast previously created as a guide. Microscopic analyses (optical stereomicroscope and scanning electron microscope) of the post surfaces revealed similar features in all three groups. All posts had regular surfaces after cutting with a diamond bur. Smear layer mainly attributable to the cutting procedures covered the cut surface of some specimens. In conclusion, modulation of a fibre post using a diamondcoated bur did not show a loss of integrity of the post. Key learning points • Because of the importance of micromechanical retention, the surface integrity of fibre posts may be important for adhesion between post and composite resin.

Introduction: Fractured rotary nickel-titanium (NiTi) instruments have been classified into those... more Introduction: Fractured rotary nickel-titanium (NiTi) instruments have been classified into those that fail as a result of cyclic flexural fatigue or torsional failure or a combination of both. Clinically, NiTi rotary instruments are subjected to both torsional load and cyclic fatigue, and ongoing research aims to clarify the relative contributions of both factors to instrument separation. Methods: To date, there is no specification or international standard to test cyclic fatigue resistance of endodontic rotary instruments. As a consequence, several devices and methods have been used to investigate in vitro cyclic fatigue fracture resistance of NiTi rotary endodontic instruments. In nearly all studies reported in the endodontic literature, the rotating instrument was either confined in a glass or metal tube, in a grooved block-and-rod assembly, or in a sloped metal block. Results: There has been no mention of the ''fit'' of the instrument in the tube or groove. As the instrument is likely to be fitting loosely, the description of the radius of curvature in those studies is likely to be overstated (ie, the file was actually bent less severely than reported, adding a variability in the amount of flexural stress). Conclusions: This review analyzed several devices that have been used in endodontic literature for cyclic fatigue testing and found that differences in the methodology affected the fatigue behavior of rotary instruments and, consequently, the outcome of these studies. An international standard for cyclic fatigue testing of NiTi rotary instruments is required to ensure uniformity of methodology and comparable results. (

Journal of endodontics, 2007

During the past few decades endodontic treatment has benefited from the development of new techni... more During the past few decades endodontic treatment has benefited from the development of new techniques and equipment, which have improved outcome and predictability. Important attributes such as the operating microscope and ultrasonics (US) have found indispensable applications in a number of dental procedures in periodontology, to a much lesser extent in restorative dentistry, while being very prominently used in endodontics. US in endodontics has enhanced the quality of treatment and represents an important adjunct in the treatment of difficult cases. Since its introduction, US has become increasingly more useful in applications such as gaining access to canal openings, cleaning and shaping, obturation of root canals, removal of intracanal materials and obstructions, and endodontic surgery. This comprehensive review of the literature aims at presenting the numerous uses of US in clinical endodontics and emphasizes the broad applications in a modern-day endodontic practice.

Journal of Endodontics, 2008

The aim of this study was to compare the effectiveness of the Mtwo R (Sweden & Martina, Padova, I... more The aim of this study was to compare the effectiveness of the Mtwo R (Sweden & Martina, Padova, Italy), ProTaper retreatment files (Dentsply-Maillefer, Ballaigues, Switzerland), and a Hedström manual technique in the removal of three different filling materials (gutta-percha, Resilon [Resilon Research LLC, Madison, CT], and EndoRez [Ultradent Products Inc, South Jordan, UT]) during retreatment. Ninety single-rooted straight premolars were instrumented and randomly divided into 9 groups of 10 teeth each (n ϭ 10) with regards to filling material and instrument used. For all roots, the following data were recorded: procedural errors, time of retreatment, apically extruded material, canal wall cleanliness through optical stereomicroscopy (OSM), and scanning electron microscopy (SEM). A linear regression analysis and three logistic regression analyses were performed to assess the level of significance set at p ϭ 0.05. The results indicated that the overall regression models were statistically significant. The Mtwo R, ProTaper retreatment files, and Resilon filling material had a positive impact in reducing the time for retreatment. Both ProTaper retreatment files and Mtwo R showed a greater extrusion of debris. For both OSM and SEM logistic regression models, the root canal apical third had the greatest impact on the score values. EndoRez filling material resulted in cleaner root canal walls using OSM analysis, whereas Resilon filling material and both enginedriven NiTi rotary techniques resulted in less clean root canal walls according to SEM analysis. In conclusion, all instruments left remnants of filling material and debris on the root canal walls irrespective of the root filling material used. Both the engine-driven NiTi rotary systems proved to be safe and fast devices for the removal of endodontic filling material. (J Endod 2008;34:466 -469)

International Endodontic Journal, 2006

Grande NM, Plotino G, Pecci R, Bedini R, Malagnino VA, Somma F. Cyclic fatigue resistance and thr... more Grande NM, Plotino G, Pecci R, Bedini R, Malagnino VA, Somma F. Cyclic fatigue resistance and three-dimensional analysis of instruments from two nickel-titanium rotary systems.

Dental Materials, 2007

ObjectivesTo evaluate the flexural modulus and flexural strength of different types of endodontic... more ObjectivesTo evaluate the flexural modulus and flexural strength of different types of endodontic post in comparison with human root dentin.

Journal of Endodontics, 2012

Introduction: The purpose of this study was to evaluate the effect of autoclave sterilization on ... more Introduction: The purpose of this study was to evaluate the effect of autoclave sterilization on cyclic fatigue resistance of rotary endodontic instruments made of traditional and new nickel-titanium (NiTi) alloys. Methods: Four NiTi rotary endodontic instruments of the same size (tip diameter 0.40 mm and constant .04 taper) were selected: K3, Mtwo, Vortex, and K3 XF prototypes. Each group was then divided into 2 subgroups, unsterilized instruments and sterilized instruments. The sterilized instruments were subjected to 10 cycles of autoclave sterilization. Twelve files from each different subgroup were tested for cyclic fatigue resistance. Means and standard deviations of number of cycles to failure (NCF) and fragment length of the fractured tip were calculated for each group, and data were statistically analyzed (P < .05). Results: Comparing the results between unsterilized and sterilized instruments for each type of file, differences were statistically significant (P < .05) only between sterilized and unsterilized K3XF files (762 versus 651 NCF). The other instruments did not show significant differences (P > .05) in the mean NCF as a result of sterilization cycles (K3, 424 versus 439 NCF; Mtwo, 409 versus 419 NCF; Vortex, 454 versus 480 NCF). Comparing the results among the different groups, K3 XF (either sterilized or not) showed a mean NCF significantly higher than all other files (P < .05). Conclusions: Repeated cycles of autoclave sterilization do not seem to influence the mechanical properties of NiTi endodontic instruments except for the K3 XF prototypes of rotary instruments that demonstrated a significant increase of cyclic fatigue resistance. (J Endod 2012;38:222-225)

Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2009

Objective. The objective of this study was to investigate the trajectory of NiTi rotary instrumen... more Objective. The objective of this study was to investigate the trajectory of NiTi rotary instruments of the same size but different design in an artificial root canal manufactured for cyclic fatigue test. Study design. Eight groups of instruments with tip size 25, 0.06 taper with different design were tested in a simulated root canal with an angle of curvature of 60 degrees and radius of curvature of 5 mm milled in a stainless steel block with a tapered shape corresponding to the dimensions of the instruments tested. Geometric analysis of the trajectory that each instrument followed inside the artificial canal was performed on digital images, determining 3 parameters: angle and radius of the curvature and the position of the center of the curvature. Mean values were then calculated for each group. Data were analyzed using 1-way ANOVA and Holm t test to determine any statistical difference (P Ͻ .05).

Journal of Endodontics, 2008

Tooth discoloration varies in etiology, appearance, localization, severity, and adhesion to tooth... more Tooth discoloration varies in etiology, appearance, localization, severity, and adhesion to tooth structure. It can be defined as being extrinsic or intrinsic on the basis of localization and etiology. In this review of the literature, various causes of tooth discoloration, different bleaching materials, and their applications to endodontically treated teeth have been described. In the walking bleach technique the root filling should be completed first, and a cervical seal must be established. The bleaching agent should be changed every 3-7 days. The thermocatalytic technique involves placement of a bleaching agent in the pulp chamber followed by heat application. At the end of each visit the bleaching agent is left in the tooth so that it can function as a walking bleach until the next visit. External bleaching of endodontically treated teeth with an in-office technique requires a high concentration gel. It might be a supplement to the walking bleach technique, if the results are not satisfactory after 3-4 visits. These treatments require a bonded temporary filling or a bonded resin composite to seal the access cavity. There is a deficiency of evidence-based science in the literature that addresses the prognosis of bleached nonvital teeth. Therefore, it is important to always be aware of the possible complications and risks that are associated with the different bleaching techniques. (J Endod 2008; 34:394 -407)