Influence of pretreatment of radicular dentin with erbium lasers on bond strength of fiber reinforced posts and evaluation of their retention

Svrha rada bila je istražiti učinak ispiranja aktiviranog erbijskim laserima na čvrstoću svezivanja konfekcijskih i individualnih vlaknima ojačanih kolčića cementiranih samoadhezivnim cementima na dentin korijenskog kanala, te ispitati njihovu retenciju. Ekstrahirani zubi (n=162) instrumentirani su i napunjeni Reciproc tehnikom, te pripremljeni za postavljanje kolčića. U prvoj skupini (n=132) push-out testom ispitan je utjecaj vrste kolčića (GC FIBER POST ili everStick POST), načina obrade dentina (konvencionalno ispiranje fiziološkom otopinom, ispiranje fiziološkom otopinom i aktivacija PIPS nastavkom Er:YAG lasera ili ispiranje i aktivacija RTF2 nastavkom Er,Cr:YSGG lasera) i tipa samoadhezivnog cementa (G-CEM LinkAce, RelyX U200 ili SpeedCEM) na vrijednost čvrstoće svezivanja. Rezultati su izraženi u MPa, logaritmirani i analizirani faktorskim ANOVA testom (p≤0.05), te post-hoc Tukeyjevim testom. U drugoj skupini (n=30) pull-out testom ispitana je retencija vlaknima ojačanih kolčića (GC FIBER POST i everStick POST) cementiranih samoadhezivnim cementom s najboljim rezultatom push-out testa. Rezultati su izraženi u N i analizirani Studentovim t-testom (p≤0.05). Relacija između duljine cementiranog dijela kolčića i sile popuštanja analizirana je modelom linearne regresije (p≤0.05 ). Za čvrstoću svezivanja statistički značajni bili su način predtretmana dentina korijenskog kanala (p=0.025) te interakcija vrste kolčića i samoadhezivnog cementa. Za retenciju statistički značajna je bila relacija između duljine cementiranog dijela kolčića i vrijednosti retencije u skupini konfekcijskog vlaknima ojačanog kolčića (p=0.01). Ispiranje fiziološkom otopinom aktiviranom Er:YAG laserom smanjilo je čvrstoću svezivanja vlaknima ojačanih kolčića cementiranih samoadhezivnim cementima na dentin korijenskog kanala u odnosu na konvencionalno ispiranje fiziološkom otopinom. Retencija konfekcijskih vlaknima ojačanih kolčića ovisila je o duljini cementiranog dijela kolčića.Objectives: The aim of this in vitro study was to investigate the effect of laser activated irrigation (LAI) with two erbium lasers on bond strength of prefabricated and individually formed fiber-reinforced composite (FRC) posts cemented with self-adhesive composite cements to root canal dentin and to examine their retention. Methods: One hundred sixty two (n=162) single-rooted human teeth were decoronated, endodontically treated and after post space preparation divided in two groups: group for evaluating bond strength using push-out test (n=132) and group for evaluating retention using pull-out test (n=30). In the first group, the teeth were further divided into two groups (n=66 per group) depending on the type of FRC posts: prefabricated GC FIBER POST (GC, Tokyo, Japan) and individually formed everStick POST (GC, Tokyo, Japan). Before cementation of posts, each group was subdivided into three subgroups (n=22 per group), according to the pretreatment of post space preparation: 1) conventional syringe irrigation with saline; 2) irrigation with saline and activation by Er:YAG laser with PIPS tip; 3) irrigation and activation by Er,Cr:YSGG laser with RFT2 tip. One specimen from each group was used for SEM evaluation to confirm the dentin pretreatment. The other specimens were divided into three groups (n=7 per group) according to the brand of self-adhesive cement: G-Cem LinkAce, SpeedCem and RelyX U200. After cementation, specimens were embedded into acrylic resin and perpendiculary sectioned into 1 mm thin sectiones. Push-out test was performed using universal testing machine (0.5 mm/min). The sliced samples were evaluated by the stereomicroscope to determine the type of failure (adhesive, cohesive or mixed). Data were calculated as megapascals, log-tranformed and statistically analyzed using factorial ANOVA (p≤0.05) and post-hoc Tukey's test. Types of failure were analyzed using Pearson's test (p≤0.05). In the second group, for pull-out testing the teeth were divided into two groups (n=15 per group) depending on the type of FRC posts: prefabricated GC FIBER POST (GC, Tokyo, Japan) and individually formed everStick POST (GC, Tokyo, Japan). Post spaces were rinsed with saline and posts were cemented with self-adhesive cement that achieved the best overall results in push-out test, in this case G-Cem LinkAce. The pull-out test was performed using modified universal device (0.5 mm/min). The tearing force (Newtons) was recorded for each sample and data were statistically analyzed using Student's t-test. The relationship between length of the cemented part of post and failure load was examined using linear regression model (p≤0.05 ) Results: In the first group,similar bond strength values were obtained for everStick POSTS and GC FIBER POSTS (p=0.15).Type of self-adhesive cement was not found significantly effective on the push-out bond strength (p=0.86). The type of dentin pretreatment (p=0.025) and interaction between type of the FRC post and self-adhesive cement influenced the bond strength. In the second group, retention was not affected by the type of FRC post. Failure load values of prefabricated FRC post were dependent on length of the cemented part of post (p=0.01). Conclusions: Irrigation with saline activated by Er:YAG lowered bond strength of both types of FRC post cemented with different self-adhesive cements in comparison with conventional syringe irrigation with saline. Retention of prefabricated FRC post was influenced by length of cemented part of the post

Influence of pretreatment of radicular dentin with erbium lasers on bond strength of fiber reinforced posts and evaluation of their retention

Svrha rada bila je istražiti učinak ispiranja aktiviranog erbijskim laserima na čvrstoću svezivanja konfekcijskih i individualnih vlaknima ojačanih kolčića cementiranih samoadhezivnim cementima na dentin korijenskog kanala, te ispitati njihovu retenciju. Ekstrahirani zubi (n=162) instrumentirani su i napunjeni Reciproc tehnikom, te pripremljeni za postavljanje kolčića. U prvoj skupini (n=132) push-out testom ispitan je utjecaj vrste kolčića (GC FIBER POST ili everStick POST), načina obrade dentina (konvencionalno ispiranje fiziološkom otopinom, ispiranje fiziološkom otopinom i aktivacija PIPS nastavkom Er:YAG lasera ili ispiranje i aktivacija RTF2 nastavkom Er,Cr:YSGG lasera) i tipa samoadhezivnog cementa (G-CEM LinkAce, RelyX U200 ili SpeedCEM) na vrijednost čvrstoće svezivanja. Rezultati su izraženi u MPa, logaritmirani i analizirani faktorskim ANOVA testom (p≤0.05), te post-hoc Tukeyjevim testom. U drugoj skupini (n=30) pull-out testom ispitana je retencija vlaknima ojačanih kolčića (GC FIBER POST i everStick POST) cementiranih samoadhezivnim cementom s najboljim rezultatom push-out testa. Rezultati su izraženi u N i analizirani Studentovim t-testom (p≤0.05). Relacija između duljine cementiranog dijela kolčića i sile popuštanja analizirana je modelom linearne regresije (p≤0.05 ). Za čvrstoću svezivanja statistički značajni bili su način predtretmana dentina korijenskog kanala (p=0.025) te interakcija vrste kolčića i samoadhezivnog cementa. Za retenciju statistički značajna je bila relacija između duljine cementiranog dijela kolčića i vrijednosti retencije u skupini konfekcijskog vlaknima ojačanog kolčića (p=0.01). Ispiranje fiziološkom otopinom aktiviranom Er:YAG laserom smanjilo je čvrstoću svezivanja vlaknima ojačanih kolčića cementiranih samoadhezivnim cementima na dentin korijenskog kanala u odnosu na konvencionalno ispiranje fiziološkom otopinom. Retencija konfekcijskih vlaknima ojačanih kolčića ovisila je o duljini cementiranog dijela kolčića.Objectives: The aim of this in vitro study was to investigate the effect of laser activated irrigation (LAI) with two erbium lasers on bond strength of prefabricated and individually formed fiber-reinforced composite (FRC) posts cemented with self-adhesive composite cements to root canal dentin and to examine their retention. Methods: One hundred sixty two (n=162) single-rooted human teeth were decoronated, endodontically treated and after post space preparation divided in two groups: group for evaluating bond strength using push-out test (n=132) and group for evaluating retention using pull-out test (n=30). In the first group, the teeth were further divided into two groups (n=66 per group) depending on the type of FRC posts: prefabricated GC FIBER POST (GC, Tokyo, Japan) and individually formed everStick POST (GC, Tokyo, Japan). Before cementation of posts, each group was subdivided into three subgroups (n=22 per group), according to the pretreatment of post space preparation: 1) conventional syringe irrigation with saline; 2) irrigation with saline and activation by Er:YAG laser with PIPS tip; 3) irrigation and activation by Er,Cr:YSGG laser with RFT2 tip. One specimen from each group was used for SEM evaluation to confirm the dentin pretreatment. The other specimens were divided into three groups (n=7 per group) according to the brand of self-adhesive cement: G-Cem LinkAce, SpeedCem and RelyX U200. After cementation, specimens were embedded into acrylic resin and perpendiculary sectioned into 1 mm thin sectiones. Push-out test was performed using universal testing machine (0.5 mm/min). The sliced samples were evaluated by the stereomicroscope to determine the type of failure (adhesive, cohesive or mixed). Data were calculated as megapascals, log-tranformed and statistically analyzed using factorial ANOVA (p≤0.05) and post-hoc Tukey's test. Types of failure were analyzed using Pearson's test (p≤0.05). In the second group, for pull-out testing the teeth were divided into two groups (n=15 per group) depending on the type of FRC posts: prefabricated GC FIBER POST (GC, Tokyo, Japan) and individually formed everStick POST (GC, Tokyo, Japan). Post spaces were rinsed with saline and posts were cemented with self-adhesive cement that achieved the best overall results in push-out test, in this case G-Cem LinkAce. The pull-out test was performed using modified universal device (0.5 mm/min). The tearing force (Newtons) was recorded for each sample and data were statistically analyzed using Student's t-test. The relationship between length of the cemented part of post and failure load was examined using linear regression model (p≤0.05 ) Results: In the first group,similar bond strength values were obtained for everStick POSTS and GC FIBER POSTS (p=0.15).Type of self-adhesive cement was not found significantly effective on the push-out bond strength (p=0.86). The type of dentin pretreatment (p=0.025) and interaction between type of the FRC post and self-adhesive cement influenced the bond strength. In the second group, retention was not affected by the type of FRC post. Failure load values of prefabricated FRC post were dependent on length of the cemented part of post (p=0.01). Conclusions: Irrigation with saline activated by Er:YAG lowered bond strength of both types of FRC post cemented with different self-adhesive cements in comparison with conventional syringe irrigation with saline. Retention of prefabricated FRC post was influenced by length of cemented part of the post

Influence of Laser Activated Irrigation with Erbium Lasers on Bond Strength of Inidividually Formed Fiber Reinforced Composite Posts to Root Canal Dentin

Svrha: Željelo se in vitro istražiti učinak ispiranja aktiviranog različitim erbijskim laserima na čvrstoću vezivanja individualnog kolčića ojačanog vlaknima na dentin korijenskog kanala. Materijali i metode: Dvadeset i sedam jednokorijenskih zuba endodontski su tretirani i poslije preparacije za postavljanje intrakanalnog kolčića podijeljeni u tri skupine (n = 9 po skupini), ovisno o vrsti predtretmana korijenskog dentina: 1. skupina – konvencionalno ispiranje fiziološkom otopinom (kontrolna skupina); 2. skupina – ispiranje fiziološkom otopinom i aktivacija PIPS nastavkom lasera Er:YAG; 3. skupina – ispiranje i aktivacija RFT2 nastavkom lasera Er,Cr:YSGG. Dva uzorka iz svake skupine upotrijebljena su za SEM analizu. U preostale je (n = 7 po skupini) cementiran individualni kolčić ojačan vlaknima everStick POST – korišten je samoadhezivni cement G-CEM LinkAce. Nakon cementiranja uzorci su prerezani okomito na uzdužnu os na nove jedan milimetar debele uzorke koji su podvrgnuti push-out testiranju (0,5 mm/min.). Rezultati su zabilježeni u MPa-u, a logaritmirani i statistički analizirani su ANOVA testom na razini značajnosti od 5 posto. Rezultati: U kontrolnoj skupini zaostatni sloj bio je još prisutan, u skupni Er:YAG bio je uklonjen, a u skupini Er,Cr:YSGG bio je djelomično uklonjen. U skupini Er,Cr:YSGG postignute su najviše vrijednosti čvrstoće vezivanja, slijedila je kontrolna skupina i tek tada skupina Er:YAG. Ipak, među vrijednostima čvrstoće vezivanja spomenutih skupina nije pronađena statistički značajna razlika (p = 0,564). Zaključak: Ispiranje aktivirano nastavcima erbijskih lasera PIPS i RFT2 nije utjecalo na čvrstoću vezivanja individualnih kolčića ojačanih vlaknima na dentin korijenskog kanala.Objective: The aim of this in vitro study was to investigate the effect of laser activated irrigation (LAI) using two erbium lasers on bond strength of individually formed fiber-reinforced composite (FRC) posts to root canal dentin. Materials and methods: Twenty-seven single-rooted human teeth were endodontically treated and after post space preparation divided into three groups (n=9 per group), according to the pre-treatment of post space preparation: 1) Conventional syringe irrigation (CSI) and saline; 2) Er.YAG photon-induced photoacoustic streaming (PIPS) technique and saline; 3) Er,Cr:YSGG activated irrigation with RFT2 tip. Two specimens from each group were used for SEM analysis. The remaining specimens (n=7 per group) received individually formed FRC post, everStick POST, luted with self-adhesive cement, G-CEM LinkAce. After cementation, the roots were perpendicularly sectioned into 1 mm thin sections and a push-out test was carried out (0.5 mm/min). The data were calculated as megapascals and were log transformed and statistically analysed using one-way ANOVA at the level of significance set at 5%. Results: In the control group, the smear layer was still present. In the Er:YAG group, the smear layer was removed. In the Er,Cr:YSGG group, the smear layer was partially removed. The Er,Cr:YSGG group achieved the highest bond strength values, followed by the control group and then the Er:YAG group, but no statistically significant difference was found in bond strength values in the tested group of post space pretreatment (p=0.564). Conclusions: LAI using two erbium lasers, with PIPS or RFT2 tip, did not affect the bond strength of individually formed FRC posts to root canal dentin

Esthetic Intracanal Posts

The primary function of an endodontic post is to provide retention for the core and enable full sealing of the coronal portion of the root canal. Traditionally used metal posts do not meet the requirements of modern dental medicine due to some fairly significant drawbacks such as color, corrosion potential, non-adhesive bonding and high modulus of elasticity which can lead to root fracture. Recently, esthetic ceramic and fiber reinforced posts have been manufactured in order to avoid such imperfections. Since much attention has been devoted to the esthetic aspects of dental medicine, the use of these posts with composite/ceramic cores is very common in restorative dentistry and it is actually becoming a standard. This is due to the fact that, apart from being an esthetically pleasing material, they are also biocompatible, have good physical properties and the capacity of adhesive bonding to tooth tissue and core buildup. Nonetheless, a good clinician should know how to spot the difference between them in order to select and use the appropriate post system in each specific situation