Influence of a microbrush on bonding fiber post into root canals under clinical conditions

OBJECTIVE: 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. STUDY DESIGN: 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' 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. RESULTS: 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. CONCLUSION: 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.     

A one step procedure for luting glass fibre posts: an SEM evaluation

AIM: 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). METHODOLOGY: 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. RESULTS: 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 < 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 > 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. CONCLUSIONS: 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).     

Efficacy of a self-curing adhesive-resin cement system on luting glass-fiber posts into root canals: an SEM investigation

PURPOSE: The aim of this study was to evaluate the efficacy of a new bonding-luting system in resin tag, adhesive lateral branch, and hybrid layer formation when used in combination with an experimental fiber post. MATERIALS AND METHODS: Thirty anterior teeth extracted for periodontal reasons were selected for this study. They were endodontically treated and randomly divided into three groups of 10 samples each: group 1 = Excite light-cured bonding agent in combination with Variolink II resin cement; group 2 = Excite dual-cured bonding agent self-activated by an experimental microbrush in combination with MultiLink resin cement; and group 3 = one-step bonding system in combination with Dual Link resin cement. In groups 1 and 3, the primer-adhesive solution was light cured before placing the resin cement and the post, whereas in group 2 the adhesive/luting materials were not light cured. Twenty FRC Postec translucent posts (groups 1 and 2) and 10 EndoAesthetic translucent fiber posts (group 3) were used. One week later, the root samples were processed for scanning electron microscopic (SEM) observations. RESULTS: Microscopic examinations of restored interfaces from group 2 revealed a resin-dentin interdiffusion zone higher than that seen in samples from groups 1 and 3 (P < .05). At the apical and middle thirds, the samples from group 2 showed significantly more resin tags than the other two groups. CONCLUSION: The dual-cure self-activating system showed a more uniform resin tag and resin-dentin interdiffusion zone formation along root canal walls than light-curing systems.     

Comparison between two clinical procedures for bonding fiber posts into a root canal: a microscopic investigation

The purpose of this study was to evaluate the influence of two brushes used as carriers of a primer-adhesive solution as to the formation of resin tags, adhesive lateral branches, and a hybrid layer when used to bond translucent fiber posts. Twenty endodontically treated teeth, extracted for periodontal reasons, were used. The samples were randomly divided into two groups of 10 samples each (Group 1: Microbrush + Scotchbond 1 + Rely X ARC resin cement; Group 2: small plastic brush + Scotchbond 1 + Rely X ARC 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. After luting procedures, root samples were processed for SEM observations. The adhesive system showed a resin dentin interdiffusion zone (RDIZ), resin tag, and adhesive lateral branch formation. Microscopic examination of restored interfaces of group 1 showed a higher percentage (p < 0.05) of RDIZ than those found in samples of group 2. In group 1 samples, RDIZ morphology was well detectable and uniform in all thirds of the root canals. In group 2, RDIZ was not visible in the apical third. No statistically significant differences were found among the two groups coronally and at the middle third, but the apical third of group 1 showed significantly more resin tag formation than group 2. The characteristic reverse cone shape of resin tags was always noted in the coronal and middle third of the root canals of both groups and in the apical third of group 1. In the apical third of group 2 root canals, the resin tags showed a less uniform morphology and a shorter length than those found in the other observed thirds.     

An SEM evaluation of several adhesive systems used for bonding fiber posts under clinical conditions.

OBJECTIVES: The objective of this investigation was to evaluate the effectiveness of three 'one-bottle' and two 'three step' adhesive systems (as controls) in the formation of resin tags, adhesive lateral branches and a resin dentin interdiffusion zone (RDIZ) when used to bond fiber posts under clinical conditions. This study was performed using standardized SEM observations and scoring resin tag formation and density. METHODS: Fifty root canal 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 allocated to five groups of ten samples each. Group 1: All Bond 2 with C & B (Bisco); Group 2: Scotchbond Multipurpose Plus with Opal Luting Composite (3M); Group 3: Scotchbond 1 in combination with Rely X ARC resin cement (3M); Group 4: One-step with C & B resin cement (Bisco); Group 5: All Bond Experimental with Post Cement HI-X (Bisco). The adhesive systems and resin cements were used strictly according to the manufacturers' instructions. The priming-adhesive solution of each 'one-bottle' system was light-cured before placing the resin cement and the post. Fifty Aestheti-Plus posts (white quartz fiber posts, RTD, France) were used. A week later, the roots were extracted and processed for SEM observations. RESULTS: All the adhesive systems showed a RDIZ and resin tag and adhesive lateral branch formation. Microscopic examination of the restored interfaces of Groups 1 and 2 showed a higher percent of RDIZ than those found in samples of Groups 3, 4 and 5. RDIZ morphology was easily detectable and uniform in the first two thirds of the root canals, whilst in the apical third the RDIZ was not uniformly present. Resin tag morphology and formation were significantly more detectable in the cervical and middle areas than in the apical zone. No statistically significant differences were found among the five groups coronally, while in the apical and middle thirds two 'one-bottle' systems (Groups 3 and 4) showed significantly less resin tags than the control Groups 1, 2 and the experimental Group 5. No statistically significant differences were found among the three 'one-bottle' systems in the three evaluated areas. The standardization of SEM observations and scoring resin tag formation allowed statistical evaluation. CONCLUSIONS: The 'three step' adhesive systems can create a wider micromechanical interlocking between adhesive materials and etched dentin than 'one-step' systems.     

Influence of brush type as a carrier of adhesive solutions and paper points as an adhesive-excess remover on the resin bond to root dentin

PURPOSE: To evaluate the influence of the brush type as a carrier of priming adhesive solutions and the use of paper points as a remover of the excess of these solutions on the push-out bond strength of resin cement to bovine root dentin. The null hypotheses were that brush type and the use of paper points do not affect the bond strength. MATERIALS AND METHODS: The canals of 80 single-root bovine roots (16 mm in length) were prepared at 12 mm using the preparation drill (FRC Postec Plus, Ivoclar). Half of each root was embedded in acrylic resin and the specimens were divided into 8 groups, considering the factors "brush type" (4 levels) and "paper point" (2 levels) (n = 10): Gr 1: small microbrush (Cavi-Tip, SDI); Gr 2: Microbrush (Dentsply); Gr 3: Endobrush (Bisco); Gr 4: conventional brush (Bisco); Gr 5: Cavi-Tip (SDI) + paper points; Gr 6: Microbrush (Dentsply) + paper points; Gr 7: Endobrush (Bisco) + paper points; Gr 8: conventional brush (Bisco) + paper points. The root dentin was treated with a multistep total-etch adhesive system (All Bond 2). The adhesive system was applied using each microbrush, with and without using paper points. One fiber post was molded with addition silicon and 80 posts were made of resin cement (Duolink). The resin posts were luted (Duolink resin cement), and the specimens were stored for 24 h in water at 37 degrees C. Each specimen was cut into 4 disk-shaped samples (1.8 mm in thickness), which were submitted to the push-out test. RESULTS: The brush type (p < 0.0001) (small microbrush > microbrush = endobrush = conventional brush) and the use of paper points (p = 0.0001) (with > without) influenced the bond strength significantly (two-way ANOVA). The null hypotheses were rejected. CONCLUSION: The smallest brush (Cavi-Tip) and the use of paper points significantly improved the resin bond to bovine root dentin.     

SEM observation of the bond integrity of fiber-reinforced composite posts cemented into root canals.

OBJECTIVES: To test the null hypothesis that continuity of resin cement/dentin interfaces is not affected by location along the root canal walls or water storage for 3 months when bonding fiber posts into root canals. METHODS: Fiber posts were luted to bovine incisors using four resinous luting systems: Multilink, Variolink II, Enforce Dual and Enforce PV. After cementation, roots were longitudinally sectioned and epoxy resin replicas were prepared for SEM analysis (baseline). The original halves were immersed in solvent, replicated and evaluated. After 3 months water storage and a second solvent immersion, a new set of replicas were made and analyzed. The ratio (%) between the length (mm) of available bonding interface and the actual extension of bonded cement/dentin interface was calculated. RESULTS: Significant lower percent values of bond integrity were found for Multilink (8.25%) and Variolink II (10.08%) when compared to Enforce Dual (25.11%) and Enforce PV (27.0%) at baseline analysis. The same trend was observed after immersion in solvent, with no significant changes. However, bond integrity was significantly reduced after 3 months water storage and a second solvent immersion to values below 5% (Multilink=3.31%, Variolink=1.87%, Enforce Dual=1.20%, and Enforce PV=0.75%). The majority of gaps were depicted at the apical and middle thirds at baseline and after immersion in solvent. After 3 months, gaps were also detected at the cervical third. SIGNIFICANCE: Bond integrity at the cement/dentin interface was surprisingly low after cementation of fiber posts to root canals with all resin cements. That was not significantly altered after immersion in solvent, but was further compromised after 3 months water storage. Gaps were mainly seen at middle and apical thirds throughout the experiment and extended to the cervical third after water storage for 3 months. Bond integrity of fiber posts luted to root canals was affected both by location and water storage.     

Effect of ethanol application on post-luting to intraradicular dentine

Aim  To examine the effect of the application of an ethanol rinse before luting fibre posts to intraradicular dentine with etch-and-rinse adhesive systems by means of push-out bond strength evaluation and scanning electron microscopic (SEM) analysis.
Methodology  Fibre posts were luted to single-canal premolars using Dual Link as a luting agent in combination with a three-step (All Bond 2) or a two-step (One Step Plus) etch-and-rinse adhesive system, which were applied as per manufacturers' instructions (control) or with the additional rinse of ethanol on acid-etched dentine prior to the bonding procedures (experimental). Bonded specimens were sectioned into 1-mm-thick slabs and subjected to push-out bond strength testing. In addition, specimens from each group were processed for SEM analysis. Data were analysed by Kruskal–Wallis followed by Dunn's post hoc test at P  = 0.05.
Results  Push-out bond strength of All Bond 2 was significantly increased if the adhesive was applied on ethanol-saturated dentine ( P  < 0.05), whilst no significant difference ( P  > 0.05) was detected amongst experimental and control groups for One Step Plus. Irrespective of the adhesive, the SEM analysis revealed good impregnation patterns when both bonding techniques were employed.
Conclusions  The use of the additional ethanol rinse on acid-etched dentine revealed higher bond strength of All Bond 2 when compared with the control application procedure, used in combination with a resin-based cement to lute fibre posts into the dowel space. However, no bond strength improvements were detected using One Step Plus. Further investigations are needed to develop a clinically applicable ethanol/bonding/luting technique.     

离体牙经不同根管封闭剂充填后纤维桩剪切粘结强度的对比研究

目的：研究不同根管封闭剂对两种纤维桩固位力的影响。方法：24颗离体上颌中切牙,截冠、预备根管,按根管封闭材料及纤维桩不同均分为4组。C-RP组：Cortisomol丁香酚类封闭剂,Rebilda Post纤维桩;C-ML组：Cortisomol封闭剂,Mac-rolockTM Post纤维桩;G-RP组：Guttaflow非丁香酚类封闭剂,Rebilda Post纤维桩;G-ML组：Guttaflow封闭剂,MacrolockTM Post纤维桩。自酸蚀粘结剂将纤维桩粘固,牙根切成1.5 mm薄片,行薄片推出实验,并观察断裂模式。扫描电镜观察粘结界面的显微结构。结果：C-RP、C-ML、G-RP、G-ML 4组剪切粘结强度（MPa）分别为5.89±2.89、7.46±2.71、7.66±3.00、9.24±3.03,C-RP粘结强度最低（P〈0.05）。牙根颈、中、根尖部的剪切粘结强度依次降低（P〈0.01）。扫描电镜观察：相比根尖部,颈部有明显树脂突;使用Guttaflow封闭剂组混合层厚度以及树脂突数目、长度优于使用Cortisomol组。结论：使用丁香酚类根管封闭会降低纤维桩剪切粘结强度;纤维桩修复后根尖部的粘结强度有待增强。     

不同材料根管桩剪切粘结强度的比较

目的:比较新型石英纤维强化树脂桩和铸造不锈钢桩与树脂类粘结剂粘结后剪切粘结强度的差异,为临床合理选择桩核系统、优化修复设计提供实验依据。方法:选用正常人离体上颌中切牙20颗随机分成两组,截冠处理并预备桩道。制作40个环氧树脂立方体模块并于中央备洞。将两组牙根固定于模块中,分别粘结石英纤维桩与不锈钢桩的一端于牙根桩道内,另一端均用自凝塑料垂直固定于模块中央。模块与力学试验机拉力杆相连,加载速度1mm/min,方向为平行于桩的长轴与牙根脱离的方向剪切牵拉。记录根管桩脱离时的最大载荷和脱落模式。结果:石英纤维桩组的剪切粘结强度(360.58N±19.12N)高于铸造不锈钢桩组(250.82N±22.34N),完全随机设计资料的t检验显示P<0.05,两者差异有显著性。结论:石英纤维桩与树脂类粘结剂的剪切粘结强度明显优于传统铸造镍铬合金桩与粘结剂;石英纤维桩可成为美容牙科修复的有效选择。     

纤维桩与根管不同处理后剪切粘结强度实验研究及电镜观察

目的比较四种不同粘结系统处理后纤维桩与根管各部剪切粘结强度,探讨其内在机理。方法 25颗完整离体尖牙于釉牙骨质界冠方2mm处截冠。根管治疗后分五组修复：DTlight纤维桩＋3M Unicem组,DTlight纤维桩＋可乐丽DCcore组,DTlight纤维桩＋Dual-link（Bisco）组,DTlight纤维桩＋Lux-acoreZ组（纤维桩表面涂布粘结剂）,DTlight纤维桩＋Luxacore组（纤维桩表面未涂布粘结剂）。包埋后切片对不同根管段行剪切粘结实验,体视显微镜下观察断裂模式,记录数据并统计分析;每组选取2个样本进行扫描电镜观察粘结界面形态。结果剪切粘结强度（MPa）依次为：6.61±1.82,7.72±2.03,5.35±1.42,10.15±0.67,7.25±0.71。体视显微镜观察显示绝大部分样本的断裂方式都是树脂/纤维桩界面断裂。扫描电镜观察显示不同处理后其显微结构各不相同。结论纤维桩修复的剪切粘结强度与粘结部位、粘结材料密切相关。     

不同黏结方法和不同桩道部位对纤维桩黏结强度的影响

目的:比较不同黏结方法在不同桩道部位对纤维桩黏结剪切强度的影响。方法:选取42颗离体上颌中切牙,根管治疗桩道预备后根据不同的黏结方法随机分为6组,Ⅰ组为全酸蚀黏结剂Luxabond+自黏结树脂水门汀Rely X TM Unicem,Ⅱ组为全酸蚀黏结剂Luxabond+双固化树脂水门汀Luxacore,Ⅲ组为自酸蚀黏结剂Contax+自黏结树脂水门汀 Rely X TM Unicem,Ⅳ组为自酸蚀黏结剂Contax+双固化树脂水门汀Luxacore,Ⅴ组为自黏结树脂水门汀Rely X TM Unicem,Ⅵ组为双固化树脂水门汀Luxacore。纤维桩黏固后行薄片推出实验,并在扫描电镜下观察黏结界面及根管内壁的微观形态。采用SPSS13.0软件包对数据进行统计学分析。结果:不同黏结方法纤维桩的黏结强度差异具有显著性(P<0.05),第Ⅰ组和第Ⅲ组的黏结强度最高。扫描电镜观察,Ⅰ组和Ⅱ组的黏结界面有树脂突形成,黏结界面也更加致密。结论:自黏结树脂水门汀Rely XTM Unicem若配合使用全酸蚀及自酸蚀黏结剂,可显著提高纤维桩的黏结强度。     

Retention of radicular posts varying the application technique of the adhesive system and luting agent

This study evaluated in vitro the retention of intracanal cast posts cemented with dual-cure resin varying the application method of the primer/adhesive solution and luting agent in the prosthetic space prepared to receive the posts. Sixty endodontically treated maxillary canines had their crowns discarded, and their roots were embedded in acrylic resin. The prosthetic spaces were prepared with Largo burs mounted on a low-speed handpiece coupled to a parallelometer in order to maintain length and diameter of intraradicular posts constant and to guarantee that the preparations were parallel after casting. Two groups (n = 30) were randomly formed according to the device used to apply the adhesive system: microbrush or standard bristle brush (control). Each group was divided into 3 subgroups (n = 10) according to the technique used to place the luting agent into the root canal: using only a lentulo spiral before setting the post, applying it onto the post surface, or combining both methods. After 72 hours, the tensile force required to dislodge each post was determined by a universal testing machine (Instron 4444) set at a speed of 1 mm/min. The results indicated that the use of the microbrush yielded higher bond strength values (0.1740 +/- 0.04 kN) than those recorded for the bristle brush tip (0.1369 +/- 0.04 kN, p < 0.001). Bonferroni's test demonstrated a higher retention (p < 0.001) in radicular post cemented with the technique that combined both methods (lentulo + post: 0.1787 +/- 0.03 kN) than that obtained with lentulo (0.1461 +/- 0.065 kN) or post (0.1416 +/- 0.03 kN) alone. The interactions between the adhesive system and luting agent application techniques presented statistical difference (p < 0.001). It was concluded that the best performance in terms of tensile strength among the tested conditions was obtained when the adhesive system was applied with a microbrush and the luting agent was taken into the root canal with lentulo spirals alone (0.1961 +/- 0.04 kN) and combining both methods (lentulo + post: 0.1911 +/- 0.02 kN).     

Effect of chlorhexidine and ethanol-wet bonding with a hydrophobic adhesive to intraradicular dentine

Purpose

To evaluate the effect of adjunctive application of ethanol-wet bonding and chlorhexidine (CHX) with a hydrophobic adhesive on bond durability of fibre posts to intraradicular dentine.

Methods

Ninety-six extracted human teeth with a single root and root canal were prepared for post placement after endodontic treatment. The teeth were randomly divided into four groups (n = 24) after etching and rinsing for rewetting: Group 1: water-wet bonding, Group 2: water-wet bonding with CHX, Group 3: ethanol-wet bonding and Group 4: ethanol-wet bonding with CHX. Teeth in Groups 1 and 2 were treated with either distilled water or distilled water with 2% CHX for 60 s; while teeth in Groups 3 and 4 were treated with either 100% ethanol or 100% ethanol with 2% CHX. Two coats of primer, followed by neat resin were applied and light-cured for 40 s. Fibre posts were luted to bonded root dentine using dual-cure resin cement. Bonded roots were subjected to push-out bond strength testing and interfacial nanoleakage evaluation after 24 h, 6 and 12 months of storage. Data were analyzed using 3-way ANOVA (rewetting solutions, time and post space regions) and SNK tests.

Results

Groups 3 and 4 showed significantly (p < 0.05) higher bond strengths and lower nanoleakage than Groups 1 and 2 after 12 months of ageing. Addition of 2% chlorhexidine to ethanol-wet bonding with a hydrophobic adhesive did not further improve the bonding of a fibre post to intraradicular dentine, when compared to ethanol-wet bonding alone after 12 months of ageing.

Clinical significance

Ethanol-wet bonding with a hydrophobic adhesive alone could improve the bond durability of fibre post to intraradicular dentine and therefore would increase the success rate of post and core restorations of endodontically treated teeth.     

Microtensile bond strength of photoactivated and autopolymerized adhesive systems to root dentin using translucent and opaque fiber-reinforced composite posts

STATEMENT OF PROBLEM: The use of fiber-reinforced composite resin posts in endodontically treated teeth has increased. However, selecting an adhesive system that provides reliable and long-lasting bonding to root canal dentin remains difficult. PURPOSE: This study evaluated the microtensile bond strength of 2 adhesive systems to root dentin and 2 different fiber-reinforced composite resin posts. MATERIAL AND METHODS: Forty single-rooted teeth were instrumented, and root canals were prepared for translucent (Light Post [LP]) or opaque (Aestheti Post [AP]) quartz fiber-reinforced composite resin posts. Two adhesive systems were used: Scotchbond Multi-Purpose Plus (SBMP) (autopolymerized) as a control group, and Single Bond (SB) (photoactivated). Teeth were assigned to 4 groups (n=10): SBMP+LP, SBMP+AP, SB+LP, SB+AP. After post cementation, roots were perpendicularly sectioned into 1-mm-thick slices, which were trimmed to obtain dumbbell-shaped specimens. The specimens were divided into 3 regions: cervical (C), middle (M), and apical (A). To determine the bond strength, the bonding area of each specimen was calculated, and specimens were attached to a device to test microtensile strength at a crosshead speed of 1 mm/min. Data were analyzed using 3-way analysis of variance and the Tukey test (alpha=.05). Fractured specimens were examined under a x 25 stereomicroscope to determine the mode of fracture. RESULTS: There were significant differences only among root dentin regions (P<.001). The cervical third (9.16 +/- 1.18 MPa) presented higher mean bond strength values, especially for SBMP. Middle and apical regions demonstrated lower values (7.08 +/- 0.92 and 7.31 +/- 0.60 MPa, respectively). Adhesive and post main factors did not demonstrate significance. Also, no interaction was significant. No cohesive fractures within resin cement, fiber-reinforced composite resin post, or root dentin were identified. CONCLUSIONS: Both adhesive systems tested demonstrated reliable bonding when used with translucent and opaque fiber-reinforced composite posts.     

Morphological study of fiber-reinforced post-bonding system-root dentin interface by evaluation of two bonding systems

Morphological study of fiber post/bonding system/root dentin interface by evaluation of two bonding systems. OBJECTIVES: The aim of the study was to analyze the interfaces, and thus the seal, between root dentin and bonded fiber-reinforced posts. The interfaces were obtained by applying two enamel-dentin adhesive systems, a one-bottle system used after application of phosphoric acid and a self-etch system, both used with an adhesive cement. The interface was evaluated by SEM observation of the continuity of the hybrid layer and the morphology of the resin tags, in terms of length, density and presence of side branches, at the interface between the fiber-reinforced post, the bonding system and the root dentin. METHODS: Twenty-six anterior single-rooted teeth extracted for periodontal reasons were treated endodontically and then randomly separated into two groups of 13 teeth each: group 1: Excite DSC (Ivoclar Vivadent, Liechtenstein); group 2: AdheSE DC (Ivoclar Vivadent, Schaan, Liechtenstein). After preparation of the root canal and application of the adhesive, each specimen received a Postec translucent FRC post (Ivoclar Vivadent, Schaan, Liechtenstein) that was cemented in with Variolink II dual-curing luting composite (Ivoclar Vivadent, Schaan, Liechtenstein). The specimens were then prepared for SEM observation of the continuity of the hybrid layer and scoring of the morphology of the resin tags in each third of the root (at 1, 4.5 and 8mm from the coronal surface). RESULTS: There was no significant difference (at p<0.05) between the two groups in terms of continuity of the hybrid layer or morphology of the resin tags. The hybrid layer was present, unbroken and uniform in both the group where adhesive was used with a phosphoric acid total etch and the self-etch system group. Whatever the bonding system, the resin tags had side branches, and greater length and density in the cervical third than in the middle or apical thirds. Bubbles were found in the cement layer in most of the specimens. CONCLUSIONS: The one-bottle and self-etch bonding systems gave similar results in terms of interface morphology when a translucent fiber-reinforced post was cemented into the endodontically prepared roots.     

Morphological and bond strength evaluation of different resin cements to root dentin

This study correlated the morphological characteristics with the bond strengths of various resin cements used for bonding fiber posts to root canal dentin. Fifty glass-fiber posts (FRC Postec Plus) were luted into the root canals of extracted human anterior teeth using five resin cements ( n  = 10): Panavia F 2.0, PermaFlo DC, Variolink II, RelyX Unicem, and Clearfil Core. Before insertion of the post, the adhesive systems were labeled with fluorescein and the resin cement was labeled with rhodamine isothiocyanate. The roots were sectioned into three slices (of 2 mm thickness), and each slice was analyzed using confocal laser scanning microscopy in dual fluorescence mode to determine hybrid layer thickness, the number of resin tags, and the number of broken tags. Bond strengths were measured using a micro push-out test. Bond strengths to root canal dentin, as well as the morphological characteristics, were significantly affected by the materials. However, these factors did not correlate. The self-adhesive resin cement, which showed the formation of a hybrid layer and resin tags only sporadically, had the highest bond strengths. These results indicate that chemical interactions between the adhesive cement and hydroxyapatite may be more crucial for root dentin bonding than the ability of the same material to hybridize dentin.     

不同厚度树脂水门汀及不同根管部位对纤维桩粘固效果的影响

目的比较不同厚度树脂水门汀及不同根管部位对纤维桩粘固效果的影响。方法32个单根管离体前牙截冠后常规根管治疗,随机分为四组,按不同桩道直径（1.1mm、1.25mm、1.35mm、1.5mm）进行根管预备,并通过自酸蚀粘结系统及树脂水门汀将直径1.1mm规格纤维桩粘固于预备后的根管内,切割为1.5mm厚试件并将其按照根管深度分为上部、中部和下部,分别测试其推出强度。结果与对照组1.1mm相比,在相同根管部位,1.25mm、1.35mm的推出强度较高（P〈0.05）,1.5mm最低（P〈0.05）,各组内根管上部推出强度显著高于下部（P〈0.05）。结论树脂水门汀厚度及根管部位对纤维桩的固位效果产生一定的影响。     

纤维桩和粘接系统对粘接界面形态及破坏方式影响的研究

目的 比较不同粘接系统粘接2种纤维桩后在桩道不同深度的粘接界面形态和界面破坏方式.方法 选取36颗新鲜上颌前磨牙,将其分成A、B、C、D组,A组:自粘接树脂黏固剂和POPO玻璃纤维桩;B组:全酸蚀粘接系统和POPO玻璃纤维桩;C组:自粘接树脂黏固剂和Para Post玻璃纤维桩;D组:全酸蚀粘接系统和Para Post...     

纤维桩导光性对根管内树脂水门汀聚合的影响

目的:评价2种不同导光性能的纤维桩对根管深部树脂水门汀聚合程度的影响.方法:16颗单根人前磨牙去冠后根管预备,随机分为导光组和非导光组(n=8).分别以i-TFC导光纤维桩和非导光性Pananiva纤维桩联合光固化树脂水门汀行桩核修复.每个修复后的牙根制备3枚牙本质片,依照其位置分为根颈段、根中段、根尖段.测试2组树脂水门汀在根管不同深度的努氏(Knoop)显微硬度值(HK)并计算其相对聚合度,进行双因素方差分析.结果:随根管深度的增加,2组树脂水门汀的显微硬度和相对固化率均呈下降趋势,根颈段和中段2项指标组间差异无统计学意义(P＞0.05).导光组和非导光组树脂水门汀在根尖段的HK值分别为33.25±3.04和23.80±5.93(P＜0.05).在根尖段的相对聚合度分别为69.89％与50.05％ (P＜0.05).结论:导光纤维桩有助于提高树脂水门汀在根尖区域的聚合程度.