两种纤维桩固位影响因素的剪切黏结实验研究

目的比较不同纤维桩在使用两种黏结系统时根管各部剪切黏结强度。方法24颗新鲜完整离体上中切牙于唇侧釉牙骨质界冠方2mm处截冠。根备后分组修复:碳纤维桩+全酸蚀系统组,碳纤维桩+自黏结系统组,石英纤维桩+全酸蚀系统组,石英纤维桩+自黏结系统组。包埋后置MTSSynergie综合测试仪上对不同根管段行剪切黏结实验,记录数值并行裂区方差分析。结果剪切黏结强度(MPa)依次为:11.14±1.26、5.04±0.94、11.82±1.16、6.72±1.02。石英纤维桩剪切黏结强度优于碳纤维桩,全酸蚀黏结系统优于自黏结系统,且桩与黏结系统之间有交互作用。根管由冠方向根方剪切黏结强度逐渐减弱。结论纤维桩修复的剪切黏结强度与黏结部位、黏结材料及桩材质密切相关。     

预成金属桩和纤维桩固位影响因素的剪切粘接实验

目的:比较纤维桩和预成金属桩使用不同粘接系统时根管各部的剪切粘接强度。方法:自制相同尺寸的碳纤维桩、预成金属桩,分别与全酸蚀系统ONE-STEP/C&B CEMENT或自粘接系统Rely X Unicem在人上颌中切牙根管内(n=6),用Synergie综合测试仪对各根管段行剪切粘接实验,行裂区方差分析。结果:剪切粘接强度分别为:纤维桩全酸蚀组:(11.14±1.26)MPa,纤维桩自粘接组:(5.04±0.94)MPa,金属桩全酸蚀组:(13.62±1.16)MPa,金属桩自粘接组:(7.80±1.36)MPa。预成金属桩剪切粘接强度优于碳纤维桩(P<0.000 1),全酸蚀系统优于自粘接系统(P<0.000 1)。根管各段由冠方向根方剪切粘接强度逐渐减弱。结论:预成桩修复的剪切粘接强度受桩材质、粘接系统及根管不同部位等因素的影响。     

Fracture resistance of structurally compromised root filled bovine teeth restored with accessory glass fibre posts

Aim  To evaluate the mechanical behaviour of structurally compromised root filled bovine roots after restoration with accessory glass fibre posts.
Methodology  Fifty roots of bovine teeth received conventional post preparations with a cervical diameter of 3.5 mm. The roots were assigned to five groups ( n  = 10): group MP – cast metal post, group GP – glass fibre post and group AGP – glass fibre post plus accessory glass fibre posts. In groups GP-R and AGP-R (similar to groups GP and AGP), 2 mm of coronal tooth structure were left intact. All groups were subjected to an elastic limit assay and tested in an universal machine for fracture resistance. Repeated measures anova were performed to examine differences in fracture resistance; fracture modes were analysed by Fischer's exact test.
Results  The mean fracture resistance values (kgf) were 61.8 (MP), 63.1 (GP), 55.5 (AGP), 56 (GP-R) and (53.1) AGP-R. No statistically significant difference was found between groups. The Fisher's exact test indicated significant differences ( P  < 0.05) in the fracture mode amongst groups MP, GP and AGP, indicating 100%, 50% and 10% of catastrophic fractures, respectivelly.
Conclusions  The use of accessory glass fibre posts affected the fracture mode favorably: 90% of fractures in group AGP were in the coronal third.     

不同表面处理方法对纤维桩在根管不同深度内粘接强度影响的薄片推出试验

目的：比较五种不同表面处理方法在不同根管深度内对纤维桩粘接强度的影响。方法：35颗离体上颌单根管前牙,常规根管治疗和桩道预备后根据不同表面处理方法随机分组：Ⅰ组：纤维桩表面涂布硅烷偶联剂（3M ESPERelyX Ceramic primer）;Ⅱ组：纤维桩表面涂布牙本质处理剂iBond（Heraeus,Germany）;Ⅲ组：纤维桩表面用1000目细砂纸打磨处理;Ⅳ组：纤维桩表面使用高锰酸钾溶液处理;Ⅴ组：对照组（纤维桩表面不进行任何处理）,用酸蚀凝胶加自粘接材料（32%磷酸凝胶＋Rely XUnicem）对纤维桩进行粘接,制作薄片推出试件,进行推出测试,记录薄片推出力值和薄片破坏方式计算粘结强度后进行统计学分析。结果：Ⅲ组和Ⅳ组粘接强度均值都大于对照组,组间差别有统计学意义（P〈0.05）;根管冠部粘接强度显著高于根中区和根尖区,差别有统计学意义（P〈0.05）。结论：表面处理方法可以提高纤维桩在根管内的粘接强度,砂纸打磨和高锰酸钾处理者效果好;纤维桩在根管内的粘接强度在根管冠部大于根管尖部。     

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...     

The effect of different adhesive system applications on push-out bond strengths of glass fiber posts

PURPOSE

Over the past years, the adhesion of fiber posts luted with simplified adhesive systems has been a matter of great interest. The aim of this study was to assess the post retentive potential of a self-adhesive resin cement using different adhesive systems to compare the push-out bond strengths of fiber posts.

MATERIALS AND METHODS

The post spaces of 56 mandibular premolar roots were prepared and divided into 4 experimental groups and further divided into 2 subgroups according to testing time (n=7). The fiber posts (Rely X Fiber Post) were luted with a self-adhesive resin cement (RelyX Unicem) and one of the following adhesive systems: no adhesive, a total-etch adhesive resin (Single Bond), a two-step self-etch adhesive resin (Clearfil SE Bond) and a one-step self-etch adhesive resin (Clearfil S3 Bond). Each root was cut horizontally, and 1.5 mm thick six root segments were prepared. Push-out tests were performed after one week or three months (0.5 mm/min). Statistical analysis were performed with three-way ANOVA (α=.05).

RESULTS

Cervical root segments showed higher bond strength values than middle segments. Adhesive application increased the bond strength. For one week group, the total-etch adhesive resin Single Bond showed higher bond strength than the self-adhesive resin cement RelyX Unicem applied without adhesive resin at middle region. For 3 months group, the two-step self-etch adhesive resin Clearfil SE Bond showed the highest bond strength for both regions. Regarding the time considered, Clearfil SE Bond 3 months group showed higher bond strength values than one week group.

CONCLUSION

Using the adhesive resins in combination with the self-adhesive resin cement improves the bond strengths. The bond strength values of two-step self-etch adhesive resin Clearfil SE Bond improved as time passes.     

Application of a dental adhesive using the self-etch and etch-and-rinse approaches: an 18-month clinical evaluation

BACKGROUND: Laboratory investigations have demonstrated that the application of multiple adhesive coats can increase adhesive infiltration, thereby increasing bond strength values. The authors conducted an 18-month, randomized, controlled prospective study to evaluate the clinical performance of a self-etch and an etch-and-rinse adhesive in noncarious cervical lesions. METHODS: Twenty-nine patients with at least two pairs of similarly sized lesions participated in this study. The authors placed 116 restorations in one of four groups: OS2 (phosphoric acid and dental adhesive [One-Step Plus, Bisco, Schaumburg, Ill.], following the manufacturer's recommendation [two coats]); OS4 (phosphoric acid and One-Step Plus, with four coats); TY2 (Tyrian SPE [Bisco] and One-Step Plus, following the manufacturer's recommendation [two coats]); and TY4 (Tyrian SPE and One-Step Plus, with four coats). The authors evaluated the restorations at baseline and at six, 12 and 18 months, according to modified U.S. Public Health Service criteria. (Eight of the 116 restorations were unavailable for follow-up.) RESULTS: The retention rate for the TY2 group (55.5 percent) was statistically lower than that for the TY4 (77.8 percent) and OS4 (88.9 percent) groups. Only teeth in OS4 exhibited a retention rate at 18 months that was similar to that observed at baseline. Marginal discoloration occurred in all groups, and it was statistically significantly worse in TY2. CONCLUSIONS: Multiple adhesive coats significantly improved retention rates. CLINICAL IMPLICATIONS: Applying multiple coats of adhesive with the etch-and-rinse or self-etch approach can improve retention rates of Class V resin-based composite restorations, although not to the level of the American Dental Association's guidelines for dentin and adhesive materials.     

Effect of maleic acid on the bond strength of fibre posts to root dentine

The aim of this study was to evaluate the effect of maleic acid (MA) on both the bond strength of fibre post to root dentine and smear layer removal after post space preparation. Sixty, single‐canal premolars were endodontically treated and randomly assigned to four groups: group 1 [0.9% saline solution (control]); group 2 [2.5% sodium hypochlorite (NaOCl)]; group 3 [17% ethylenediaminetetraacetic acid (EDTA) followed by 2.5% NaOCl]; and group 4 (7% MA followed by 2.5% NaOCl). Self‐adhesive resin cement was used to test the adhesion of a glass‐fibre post to the root dentine through a micropush‐out test. Scanning electron microscopy was performed to examine and score the treated specimens for smear layer removal, and stereomicroscopy was applied to investigate the failure modes of fibre posts. Maleic acid exhibited the highest mean bond‐strength values in the apical regions among all the groups. Most failure modes (31.9%) were adhesive‐type failures between the dentine and luting materials. Maleic acid performed statistically significantly better than the other groups regarding smear layer removal, especially in the apical region. Maleic acid is an effective irrigant that can remove the smear layer, open dentinal tubules, and act as a high‐efficiency final irrigant in activation protocols.     

The effect of luting cement thicknesses on the push-out bond strength of the fiber posts

Abstract

Objective. The aim of this study was to evaluate the effect of luting cement thicknesses on the push-out bond strength of the fiber posts. Materials and methods. Sixty human maxillary canine teeth were endodontically treated. Post spaces were prepared and root specimens randomly divided into three groups: Group 1: etch-and-rinse (Variolink II/Exite DSC), Group 2: self-etch (Panavia F2.0/ED primer) and Group 3: self-adhesive (Clearfil SA Cement). Then each group was divided into four sub-groups according to the cement thickness, as follows: Sub-group 1: 0.35 mm, Sub-group 2: 0.25 mm, Sub-group 3: 0.15 mm, and Sub-group 4: 0.05 mm. Three slices of 1 mm thickness were obtained from each root specimen (n = 15). Push-out tests were performed and data was analyzed with two-way ANOVA and Tukey tests. Results. The etch-and-rinse system (Variolink II) had a significantly higher bond strength compared with the other systems (?p < 0.05). The thickest cement group (0.35 mm) had a significantly lower bond strength compared with the 0.15 and 0.05 mm groups in the etch-and-rinse and self-adhesive groups (p < 0.05). In the self-etch group, the cement thicknesses did not significantly affect the bond strength (p > 0.05). Conclusions. The etch-and-rinse system offered better bonding to root dentine than the self-adhesive and self-etch systems. The increases in cement thickness significantly reduced the bond strength of fiber posts to root dentine for both the etch-and-rinse and self-adhesive systems.     

Effect of the timing of radiation therapy on the push-out strength of resin cement to root dentine

This study investigated the effect of radiation timing on the bond strength of resin cement to intraradicular dentine. Fifty human teeth were distributed into 5 groups (n = 10): Control (nonirradiated teeth), Before-RCT (teeth irradiated before root canal treatment), After-CH (teeth irradiated after canal preparation and placement of calcium hydroxide intracanal dressing), After-RCT (teeth irradiated after completion of root canal treatment) and After-FPL (teeth irradiated after luting of a glass fibre post). Each tooth received 70 Gy irradiation. The roots were sectioned for push-out strength testing. After-RCT and After-FPL groups had significantly lower push-out strength than the control at the middle third (p < 0.05). Control and After-CH groups had a higher percentage of cohesive dentine failure. Radiotherapy after root canal obturation and post luting adversely affected the adhesiveness of resin cement to intraradicular dentine. Teeth irradiated before root canal treatment and after placement of calcium hydroxide had the best performance.     

不同粘接方法对纤维桩在不同根管深度内粘接强度影响的薄片推出实验

[摘要] 目的 较4种粘接方法在不同根管深度内对纤维桩粘接强度的影响。方法 选取28颗离体上颌单根管前牙,常规根管治疗和桩道预备后根据粘接方法随机分为四组。Ⅰ:全酸蚀组(LuxaBond+LuxaCore);Ⅱ:自酸蚀组(iBond+Lux-aCore);Ⅲ:自粘接组(RelyXUnicem);Ⅳ:酸蚀加自粘接组(32%磷酸+RelyXUnicem)对纤维桩进行粘接,之后将粘接有纤维桩的牙切割成1mm厚度的薄片,记录根段部位,将薄片分为根管冠部、中部和尖部三个亚组,进行推出测试后记录薄片推出力值和薄片破坏方式。结果 Ⅰ组和Ⅳ组分别和Ⅱ组、Ⅲ组粘接强度有显著差异(P<0.05),Ⅰ组和Ⅳ组间粘接强度差别无统计学意义(P>0.05);根管冠部粘接强度显著高于尖部(P<0.05)。结论全酸蚀粘接系统粘接强度高于自粘接和自酸蚀系统;自粘接系统加用酸蚀技术可以显著提高纤维桩在根管内的粘接强度;纤维桩在根管内的粘接强度根管冠部大于尖部。     

Bond strength of fibre glass and carbon fibre posts to the root canal walls using different resin cements

The aim of the study was to evaluate the bond strength of fibre glass and carbon fibre posts in the root canal walls cemented with self-adhesive (RelyX-Unicem) and chemical (Cement-Post) resin cements. Forty maxillary canines were divided into four groups according to the cement and post used and submitted to the push-out test (0.5 mm min(-1)). The data were submitted to statistical analysis (2-way ANOVA, Bonferroni--P<0.05) and fracture analysis by Scanning Electronic Microscopy. Fibre glass presented the best results when cemented with RelyX-Unicem and Cement-Post (P<0.05). RelyX-Unicem presented the highest bond strength values for both posts (P<0.05). Fracture analysis showed predominance of cohesive fracture of post for RelyX-Unicem and adhesive fracture between dentin/cement and mixed for Cement-Post. The bond strength values were significantly affected by the type of post and cement used and the highest values were found for fibre glass posts and RelyX-Unicem.     

The effect of calcium silicate-based sealer on the push-out bond strength of fibre posts

Background: The aim of this study was to assess the effect of the iRoot SP root canal sealer on the push‐out bond strength of fibre posts cemented with self‐adhesive resin cement. Methods:  Forty‐eight extracted maxillary incisors were randomly divided into four groups according to the tested sealer (n = 12): group 1 – control (only gutta‐percha points, no sealer); group 2 – AH Plus Jet (resin‐based sealer); group 3 – Endofill (zinc oxide‐eugenol‐based sealer); and group 4 – iRoot SP (calcium silicate‐based sealer). All root canals were filled with gutta‐percha, and groups 2–4 additionally received one of the sealers. Fibre posts were cemented with the self‐adhesive resin cement Clearfil SA Cement. The specimens were sectioned in the coronal, middle and apical regions, producing three slices of 1 mm thickness. The push‐out test was performed. All data were submitted to ANOVA and Tukey tests (α = 0.05). Results:  No statistically significant differences were found between the control group, AH Plus Jet and iRoot SP (p > 0.05). The Endofill sealer showed significantly lower bond strength compared to the other sealers and the control group (p < 0.05). Conclusions:  The calcium silicate‐based sealer did not adversely affect the bond strength of the fibre posts cemented with self‐adhesive resin cement.     

不同表面处理方法及根管深度对玻璃纤维桩粘接强度的影响

目的比较4种表面处理方法以及在根管内的深度对纤维桩粘接强度的影响。方法取25颗单根管前磨牙,随机分为5组,常规根管治疗。对25根POPO纤维桩分组进行表面处理:A组(对照组),B组(过氧化氢组),C组(硅烷组),D组(氢氟酸凝胶组),E组(乙醇钠组)。将纤维桩粘接于离体牙根管内并制作薄片试样,根据根管深度将试样分为根上部、根中部、根下部3个亚组,进行微推出实验测试粘接强度。扫描电镜(SEM)下对各组纤维桩的外观形貌进行观察。结果纤维桩粘接强度为B组>D组>E组>A组,各组间差异显著(P<0.05),C组与A组间差异无统计学意义(P>0.05);纤维桩在根管不同深度的粘接强度为:根上部>根中部>根下部(P<0.05);SEM观察显示,经处理后的各组纤维桩表面形貌与对照组相比可见纤维束暴露量增加。结论除硅烷偶联剂外,HF、H2O2、乙醇钠均能显著提高玻璃纤维桩的粘接强度;随着根管深度的增加,纤维桩粘接强度逐渐减小。     

Map-reading strategy to diagnose root perforations near metallic intracanal posts by using cone beam computed tomography

Introduction

To determine the diagnostic hypothesis on the basis of periapical radiography (PR) is a great challenge for radiologists and endodontists. Visualization of three-dimensional structures, available with cone beam computed tomography (CBCT), favors precise definition of the problem and treatment planning. However, metallic artifact effect of intracanal posts might also induce untrue images. The aim of this article is to suggest a map-reading strategy to diagnose root perforations near metallic intracanal posts (ICPs) by using CBCT.

Methods and Results

The incapacity to locate correctly the position of root perforation might lead to clinical failures. One strategy to minimize metallic artifact in root perforation associated with ICP is to obtain sequential axial slices of each root, with an image navigation protocol from coronal to apical (or from apical to coronal), with axial slices of 0.2 mm/0.2 mm. This map reading provides valuable information showing dynamic visualization toward the point of communication between the root canals and the periodontal space, associated with radiolucent areas, suggesting root perforation.

Conclusions

The accurate management of CBCT images might reveal abnormality that is unable to be detected in conventional PR. A map-reading approach reduces problems related to detection of root perforations near metallic artifacts. The final diagnosis should always be made in conjunction with the clinical findings.     

玻璃纤维的表面预处理对纤维增韧树脂基桩力学性能的影响

目的 研究不同表面预处理的高强玻璃纤维对纤维增强光固化树脂复合材料（FRC）桩的力学性能的影响。方法 将玻璃纤维分为4组分别进行以下表面处理：不预处理、450 ℃高温处理、450 ℃高温+10%HCl蚀刻1 h、450 ℃高温+10% HCl蚀刻3 h,然后将4组纤维经过硅烷偶联剂处理后按相同体积比浸入自行配制的光固化树脂基质中,用压挤法制成纤维增强树脂基桩。测试试样的弯曲模量、弯曲强度、弯曲载荷,扫描电子显微镜观察FRC截面和断裂面的形态。结果 不同表面预处理后的玻璃纤维对FRC桩的力学性能有显著差异,其中450℃+KH570组制成的FRC桩性能最佳,弯曲模量、弯曲强度、弯曲载荷分别为（37.70±1.46） GPa、（737.00±25.51） MPa、（196.53±6.80） N,与其余组有显著差异（P＜0.05）。结论 450 ℃高温+KH570处理玻璃纤维对FRC桩的增韧效果最佳。     

The influence of time and cement type on push-out bond strength of fiber posts to root dentin

The bond strength of fiber posts luted with resin cements was evaluated after two storage times in different regions of a post space. A total of 40 single-rooted human teeth were endodontically treated and prepared for cementation of fiber posts (White Post DC). In groups 1 and 3 (G1 and G3, respectively), posts were luted with RelyX ARC, whereas the posts in groups 2 and 4 (G2 and G4, respectively) were luted with RelyX Unicem. After one month of storage at 100% humidity, G1 and G2 were transversally sectioned in 1.7-mm slices of the cervical (C), middle (M), and apical (A) thirds of the post space and submitted to push-out testing at 1 mm/min. After nine months of storage, the roots of G3 and G4 underwent the same process. Mean values were analyzed using the Mann-Whitney and Kruskal-Wallis tests (α=0.05). The bond strengths in G2 (C=4.26±2.29; M=4.67±3.54; A=7.27±4.30) were statistically higher than in G1 (C=3.81±1.07; M=1.57±1.62; A=1.99±1.60) in the middle and apical thirds (p=0.001). Bond strengths in G4 (C=3.36±1.39; M=4.49±2.17; A=3.83±1.92) were higher than in G3 (C=2.13±0.47; M=0.94±1.05; A=0.95±1.02) in all evaluated regions (p=0.02, p<0.001, and p<0.001, respectively). When comparing the root regions for each group, G1 had higher values in the cervical third than the middle third (p=0.02). The self-adhesive resin cement showed better results than the conventional resin cement at both storage times. For both materials a similar performance among the three root regions was found. Storage time did not influence the shear bond strength.