不同黏结材料对纤维桩修复牙根发育不完全牙抗折性能的影响

目的:观察比较不同黏结材料对牙根发育不完全牙修复后抗折强度的差异,以期为临床使用桩核系统修复根尖诱导成形术后的牙提供依据.方法:收集符合纳入标准的因正畸需要拔除的第一、二前磨牙75颗,随机分为5组,实验组2组(纤维桩+黏结材料充填)、阳性对照组2组(黏结材料桩道充填)、阴性对照组1组(根管充填后不作处理),每组15颗牙,将桩核系统修复后的样本牙进行包埋,采用TY-8000型电子万能测试机分别测量牙根颈1/3和中1/3的抗折强度,比较不同黏结材料修复对牙根抗折强度的影响.采用SAS6.0软件包对数据进行分析.结果:实验1组牙根颈、中部的抗折强度分别为(999±75.40)N、(799±21.77)N,实验2组牙根颈、中部的抗折强度分别为(896±15.73)N、(739±20.14)N.经统计学分析,2组间根颈1/3和中1/3抗折强度差异有显著性(P<0.01);各实验组与阳性对照、阴性对照组之间差异均有显著性.结论:不同黏结材料对纤维桩修复后的牙根发育不完全的牙各部位的抗折强度有影响.在牙根发育不完全牙玻璃纤维桩的修复中,建议用复合树脂水门汀作为黏结材料.     

桩-桩道间隙的匹配对纤维桩修复牙根发育不完全牙的抗折性能的影响

目的:比较3种不同直径的纤维桩插入相同的根管桩道预备间隙对牙根发育不完全牙修复后抗折强度的影响,为临床使用桩核系统修复根尖诱导成形术后的牙提供依据。方法:收集符合纳入标准的因正畸需要拔除的第一、二前磨牙75颗,随机分为5组。其中,实验组3组(3种不同直径的纤维桩+材料充填)、阳性对照组1组(材料桩道充填)、阴性对照组1组(根管充填后不作处理),每组样本牙各15颗,常规进行相同的桩道预备后,用不同直径的桩核系统修复,将修复后的样本牙进行包埋,采用TY-8000型电子万能测试机分别测量牙根颈1/3和中1/3区域的抗折强度,比较桩—桩道间隙的匹配对牙根抗折强度的影响。采用SAS6.0软件包对数据进行统计学处理。结果:实验组1(在桩道预备间隙中插入1.3mm的玻璃纤维桩)的牙根颈部、中部的抗折强度分别为(811±33.85)N、(681±26.64)N;实验组2(在桩道预备间隙中插入1.6mm的玻璃纤维桩)为(901±39.85)N、(729±28.77)N;实验组3(在桩道预备间隙中插入1.9mm的玻璃纤维桩)为(999±75.40)N和(799±21.77)N,阴性对照组分别为(501±38.4)、(472±22.98)N,阳性对照组分别为(704±88.39)、(550±20.14)N,对实验组1、2、3,阳性对照组和阴性对照组进行两两比较,发现在牙根的不同部位,抗折强度均有显著差异(P<0.001),且与阴性对照组有显著差异。其中,插入直径最大的1.9mm玻璃纤维桩的牙根,各部位的抗折能力最强。结论:桩道预备间隙对牙根抗折性能有显著影响,植入直径最大的1.9mm玻璃纤维桩的牙,在牙根颈1/3和中1/3区域都显示出比植入其他2种直径玻璃纤维桩的牙具有更大的抗折强度。     

树脂加固结合纤维桩核修复对发育不全前磨牙牙根抗折性的影响

目的探讨使用树脂加固根管内壁及纤维桩体外修复发育不完全前磨牙牙根后的抗折性差异。方法 50颗离体人下颌第一或第二前磨牙,统一冠根长度,随机均分为5组,A组、B组分别为阴性和阳性对照组,C组用复合树脂加固根管内壁,D组用纤维桩加固,E组同时用复合树脂和纤维桩加固,每组牙分别经过不同的处理后,包埋于自凝塑料中并置于电子万能测试机上,测定其抗折强度,记录各颗牙的抗折力最大值,利用ANOVA(P=0.05)软件分析各组间的抗折性差异。结果 C组、D组、E组与A、B对照组之间两两存在显著性差异,D组与E组之间也存在显著性差异。结论无论使用树脂加固根管内壁还是纤维桩修复均能显著增强根尖发育不完全前磨牙牙根的抗折性,其中同时采用两种方法修复的牙齿抗折性最强。     

新型高强度玻璃离子水门汀修复漏斗状残根的实验研究

目的：探讨应用新型高强度玻璃离子水门汀对漏斗状残根的修复效果。方法：将45个完整的上颌离体中切牙预备成漏斗状残根，随机分成3组，A组：新型高强度玻璃离子水门汀核联合成品金属螺纹桩修复。B组：双重固化型复合树脂核联合成品金属螺纹桩修复。C组：Ni-cr合金铸造桩核修复。将样本固定于电子万能测试仪上，测试抗折强度并观察折断模式。结果采用方差分析、X^2检验。结果：新型高强度玻璃离子水门汀组的牙根抗折强度已达到较高水平，与双重固化型复合树脂组的牙根抗折强度并无显著性差异，而这两组的牙根抗折强度虽然低于Ni-cr合金铸造桩核组，但其折断模式更有利于牙根的重复利用。结论：应用新型高强度玻璃离子水门汀核联合成品金属螺纹桩可用来修复漏斗状残根。     

根管内壁酸蚀处理对桩核冠修复后牙根抗折性能影响的体外实验研究

[摘要] 目的 研究铸造桩表面酸蚀处理对牙根抗折性能的影响。方法 32颗近期拔除的单根第一前磨牙,根管治疗后于釉牙骨质界冠方1.5 mm截冠,铸造桩核及金属全冠修复,随机分为4组。实验组根管内表面酸蚀分别酸蚀10 s、30 s及60 s,对照组不作处理。所有样本处理完成后均以磷酸锌水门汀粘固。试件包埋于丙烯酸树脂块中,在电子万能实验机上进行测试。结果 实验组牙根折裂强度分别为（2.981±0.102） kN、（3.097±0.084） kN、（3.128±0.071） kN,对照组牙根折裂强度为（2.699±0.445） kN,各实验组与对照组间差异均具有统计学意义（P<0.05）。结论 对根管内表面进行酸蚀处理可以提高桩核冠修复后牙根的抗折强度。     

不同桩核修复根管治疗牙抗疲劳强度的体外研究

目的:探讨不同桩核修复根管治疗牙抗疲劳强度.方法:60颗离体上颌中切牙均分为无肩领和有肩领2个实验组.各实验组再分为3部分,各10颗样牙.每部分分别用铸造金属桩核、预成碳纤维桩联合复合树脂核及预成金属桩联合复合树脂核进行修复后再进行全冠修复.测定各样本牙疲劳强度并对实验结果进行双因素方差检验(α=0.05).结果:2个实验组中,用预成碳纤维桩联合复合树脂核修复组根管治疗牙根的平均疲劳强度显著高于金属桩核修复组(P<0.05).预备牙本质肩领可显著提高3种桩核材料修复牙的疲劳强度(P<0.05).结论:纤维桩联合复合树脂核在提高前牙牙根抗疲劳强度方面优于铸造金属桩核和预成金属桩树脂核.保留牙本质肩领,对提高牙根的抗疲劳强度具有重要意义.     

桩核材料与纤维/树脂复合材料桩钉联合修复无髓牙的抗折性能研究

目的评价3种树脂类桩核材料与高强玻璃纤维/树脂复合材料(FRC)桩钉联合修复无髓牙的抗折性能。方法用FRC桩钉和3种经不同方法处理(热压和未热压)的树脂核(Artglass聚合体、Charisma复合树脂、AB组份复合树脂)联合修复离体无髓牙根,测试1300加载时的破坏载荷。结果Artglass聚合体组的抗折力最高(505.4N),经热压处理后强度明显提高(564.1N) ; Chari~复合树脂组经热压后脆性增加,强度降低(热压前后分别为411.3N和 315.3N); AB组份树脂组经热压后强度明显提高(热压前后分别为358.4N和423.4N)。实验中无1例出现桩钉折断和聚酷冠碎裂。结论不同桩核材料与FRC桩钉联合修复无髓牙的抗折力不同,其中Art乡ass聚合体组的抗折力最高,但是此3组的抗折力均超过了咀嚼过程中前牙的咬合力,树脂核与纤维/树脂复合材料桩钉联合修复无髓前牙残根可以满足临床需要。     

2种桩系统修复前磨牙近中面洞型的抗力研究

目的 比较研究根管治疗后前磨牙近中面洞型经3种方法 修复后的抗力,并评价聚乙烯纤维桩系统(Ribbond桩)修复牙体缺损对修复体抗力的影响。方法 40颗完整离体单根前磨牙分成4组。第一组为对照组,另外三组根管治疗后预备近中面洞型。第二组使用复合树脂直接充填;第三、四组分别用石英纤维桩(DTLightpost)和Ribbond桩制作桩,复合树脂直接充填。热循环10000次后,置于INSTRON测试仪上测试断裂载荷,记录试件折裂时测试机读数及试件折裂模式。结果 对照组、复合树脂组、石英纤维桩组、聚乙烯纤维桩系统组的断裂载荷依次为:(1191.04±362.59)N,(578.81±117.87)N,(909.33±250.20)N,(831.56±220.16)N。实验组断裂载荷均显著低于对照组(P<0.05),石英纤维桩和聚乙烯纤维桩系统两组间无统计学差别(P=0.50),且均高于树脂直接充填组(P<0.05)。结论 使用石英纤维桩和Ribbond桩修复前磨牙近中面洞型均显著提高了抗折能力,且Ribbond桩能够显著改善折裂模式。?     

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目的比较3种纤维桩修复下颌第一前磨牙的抗折性,并分析影响因素。方法选择2006年12年至2007年2月南昌大学附属口腔医院外科门诊因正畸需要而拔除的下颌第一前磨牙36颗,保留2mm的牙本质肩领,随机分成A、B、C3组,牙体预备后分别用3种纤维桩(A组:石英纤维桩-复合树脂核;B组:碳纤维桩-复合树脂核;C组:玻璃纤维桩-复合树脂核)及后牙树脂完成桩核修复,固定于万能材料测试机上加载直至标本发生折裂,记录标本破坏时的瞬间力值及实验牙的折裂类型。采用SPSS13.0软件包对结果作单因素方差分析。结果破坏性力学试验的测试结果为A组(399.24±33.84)N,B组(358.11±22.82)N,C组(220.32±23.98)N,对各组样本的破坏性试验力值进行单因素方差分析表明:3组的抗折强度为A>B>C(P<0.01)。结论石英纤维桩、碳纤维桩、玻璃纤维桩抗折强度依次递减,折断模式都有利于重新修复,均适用于临床修复。     

不同方法修复薄弱根管的疲劳抗折性能比较

目的 比较根管重塑后纤维桩核系统及传统铸造桩核修复薄弱根管前磨牙的疲劳抗折性能.方法 将16颗实验牙截冠后制备成薄弱根管,随机分为2组,A组根管重塑+预成纤维桩+树脂核修复;B组传统铸造桩核修复.所有样本全冠修复并进行5000次冷热水循环及30万次循环加载,再以3mm/min的速度静加载至折裂发生,记录2组试件折裂发生时的加载强度、折裂模式.结果 抗折载荷分别为A组1.79±0.26KN和B组2.35±0.22KN,差异有统计学意义.A组多见可再修复性折裂,B组多见破坏性折裂.结论 在本实验条件下,根管重塑后纤维桩核系统修复薄弱根管的疲劳抗折强度不及传统铸造桩核修复,但其折裂模式更有利于牙根的保护.     

Resin Composite Core and Fiber Post Improved the Fracture Parameters of Endodontically Treated Maxillary Premolars with Wedge-shaped Cervical Lesions

IntroductionThe aim of this study was to evaluate the fracture resistance and fracture patterns of endodontically treated maxillary premolars with wedge-shaped cervical lesions restored with a resin composite core with or without a fiber post under nonaxial loading.MethodsSixty extracted human maxillary premolars with 2 root canals were randomly allocated into 4 groups (n = 15). Forty-five teeth were prepared with a wedge-shaped lesion at the buccal cervical area and root canal treatment. There were 3 restoration groups: no restoration, restoration with a resin composite core, and restoration with a resin composite core and a fiber post. Intact teeth served as the control group. All teeth were subjected to thermocycling and cyclic loading. A 45° compressive load was applied to the palatal plane of the buccal cusp until tooth fracture. The fracture resistance and facture patterns were analyzed using 1-way analysis of variance and the chi-square test (α = 0.05), respectively.ResultsThe no restoration group demonstrated the lowest fracture resistance and was significantly different from the other groups (P < .001). The intact teeth presented the highest fracture resistance, which was not significantly different from the restoration with a resin composite core and a fiber post group (P > .05). The failure patterns were significantly different between groups (P < .001). Most intact teeth fractured coronally to the cementoenamel junction level, whereas most teeth in the other groups fractured at the gingival margin of the cervical lesion.ConclusionsEndodontically treated maxillary premolars with wedge-shaped cervical lesions restored with fiber posts and a resin composite cores had a fracture resistance equivalent to intact teeth. However, their fracture patterns were not improved by the fiber post and a resin composite core.     

Reinforcement of Simulated Immature Permanent Teeth after Mineral Trioxide Aggregate Apexification

Objectives

The objectives of this study were to compare the fracture resistance of simulated human immature teeth that have undergone mineral trioxide aggregate (MTA) apexification and have been root-filled with fiber post, composite resin, MTA, or gutta-percha.

Fracture resistance of simulated immature roots using Biodentine and fiber post compared with different canal-filling materials under aging conditions

Objective

The aim of this study was to evaluate the fracture resistance of simulated immature roots using Biodentine (BD) and fiber post (FP) compared with different root canal-filling materials under aging conditions.

Materials and methods

One hundred and forty maxillary central anterior teeth were randomly divided into seven groups (n = 20/group). Negative control received no treatment. In the other groups, the root canals were prepared to simulate immature teeth. The root canals were filled with a 4-mm apical plug of BD and restored intraradicular with BD, BD + FP, composite resin (CR), CR + FP, and gutta-percha (GP). Positive controls were instrumented but without restoration. Teeth were subjected to thermocycling and received cyclic loading before fracture resistance test. Fracture resistance was conducted using a universal testing machine with a crosshead speed of 0.5 mm/min until fracture. Load to fracture was recorded in newtons (N). Data were statistically analyzed using one-way analysis of variance and Tukey’s test at P < 0.05.

Results

Root canals restored intraradicular with BD + FP and CR + FP showed the highest fracture resistance compared with the other experimental groups (P < 0.001). There was no significant difference in the fracture resistance between CR and BD groups (P = 0.998). GP and positive control groups were significantly lower resistance to fracture than the other groups (P < 0.001).

Conclusions

Intraradicular reinforcement with BD + FP and CR + FP enhanced the fracture resistance of simulated immature teeth than the other experimental groups.

Clinical relevance

Biodentine or composite resin combined with fiber post could be used to reinforce immature teeth with an apical Biodentine plug.

     

Structural integrity of extracted teeth restored using three different post-and-core systems: An in vitro comparative study

AimThe objective of the study was to assess the in vitro fracture resistance of endodontically treated teeth restored using different post-and-core materials.Materials and methodsExtracted human mandibular premolars (n = 36) were extracted teeth and equally distributed into four (4) treatment groups: cast metal post-and-core, milled zirconia post-and-core, pre-fabricated post with composite resin core and control group. These samples were then each subjected to the load to fracture test using a universal testing machine. Fracture resistance data were compared among groups by analysis of variance and Fisher’s exact test.ResultsThe highest mean fracture resistance value was observed in the zirconia post-and-core treatment group (1567.26 ± 317.66 N), followed by the cast metal (1355.92 ± 621.56 N) and lastly the pre-fabricated post with composite resin core (725.67 ± 251.05 N) treatment group. Differences among groups were not statistically significantly different (P = 3.77).ConclusionEndodontically treated mandibular premolars with a zirconia post-and-core system exhibited the highest robustness against structural failure based on its mean fracture resistance value. In addition, extracted teeth restored with cast post-and-core resisted a greater stress load than those restored with fiber-reinforced posts. Zirconia showed a more favorable fracture mode than the other restorations.     

Influence of Smear Layer Treatment on Resistance to Root Fracture in Tooth Restored with Epoxy Fiber Post

To evaluate the influence of complete smear layer removal by EDTA on the resistance of root fracture of tooth restored with fiber post. Twenty single rooted premolars with average root length 16 ± 1 mm were randomly divided into two groups of ten each. All teeth were obturated with guttapercha after root canal preparation, sectioned 4 mm above the cement-enamel junction. In group I, teeth root canals were etched with 37 % phosphoric acid, fiber post cemented with self adhesive resin cement. In group II, teeth radicular dentin was treated with 17 % EDTA, followed by fiber post cementation with dual cure resin cement. Coronal part of the teeth reestablished with posterior composite and NiCr full veneer coping along with 2 mm circumferential ferrule. Restored teeth were loaded with incremental force at 30° to the long axis of the root until fracture occurred. The data obtained was evaluated with paired sample T test to compare the fracture resistance between the test groups. Group I had the mean failure load of 1,883.70 N while group II had 1,622.80 N mean failure load. Paired sample T test showed statistically significant (p value = 0.033) failure load difference between the groups tested. Within the limits of this study, it may be concluded that: the complete removal of smear layer by EDTA found to have reduced the fracture strength of tooth roots restored with an epoxy fiber post.     

The effect of the post length and cusp coverage on the cycling and static load of endodontically treated maxillary premolars

In endodontically treated teeth, cuspal coverage plays a fundamental role in reducing the risk of fracture. However, the adhesive techniques with or without fiber post increased the possibilities in restoring root-filled teeth. The aim of this study was to determine the effect of the fiber post and/or post length and/or cuspal coverage on the fracture resistance of endodontically treated maxillary premolars. Seventy intact single-rooted maxillary premolars were selected and divided in seven groups of ten each: “intact teeth” (control), “inlay without fiber post” (G1), “inlay with long fiber post” (G2), “inlay with short fiber post” (G3), “onlay without fiber post” (G4), “onlay with long fiber post” (G5), and “onlay with short fiber post” (G6). Except for intact teeth, all specimens were prepared with a mesio–occluso–distal (MOD) cavity, endodontically treated and restored with or without long or short post, with or without cusp coverage. All specimens were thermal-cycled, exposed to a cyclic loading, and then submitted to the static fracture resistance test. Fracture loads and mode of failure were evaluated. A statistically significant difference in fracture resistance was found between group 1 and the other groups (p < 0.001). χ2 test showed statistically significant differences in the patterns of fractures between the groups (p < 0.001). The highest number of favorable fractures was observed in groups 3 and 4. Similar fracture resistance was detected in maxillary premolars endodontically treated with MOD cavity preparations, restored with either direct resin composite with fiber post or cusp capping. The “short post” direct restoration may be a valid alternative in the restoration of root-filled premolars.     

Comparison of the Effects of Intraradicular Materials on the Incidence of Fatal Root Fracture in Immature Teeth Treated with Mineral Trioxide Aggregate Apexification: A Retrospective Study

IntroductionThis study aimed to compare the incidence of root fractures that led to extraction in immature teeth endodontically treated by mineral trioxide aggregate (MTA) apexification and were restored with either reinforced (resin composite or fiber post) or nonreinforced (gutta percha or MTA) intraradicular materials.MethodsNecrotic immature teeth treated with MTA apexification from 1996 to 2017 were selected according to the inclusion and exclusion criteria. Intraradicular materials and preoperative and treatment factors were obtained from dental charts and radiographs. The incidence of fatal root facture was identified. Kaplan-Meier survival analysis and the Cox proportional hazard model were used to show the survival rate and predisposing factors at a significance level of .05.ResultsThe average recall period was 30 months. The incidence of root fracture in the teeth restored with the reinforced materials was 5.5%, which was not significantly different from the nonreinforced materials (8.3%). Furthermore, the fracture rates between the fiber post and resin composite groups were not significantly different. Two significant predisposing factors influencing the incidence of root fracture were detected: preoperative external inflammatory root resorption (hazard ratio = 26.86; P < .05) and patient age > 15 years (hazard ratio = 8.60, P < .05).ConclusionsImmature teeth treated with MTA apexification and restored with the reinforced or nonreinforced intraradicular materials exhibited a similar rate of root fracture. Preoperative external inflammatory root resorption and patient age > 15 years were found to be the predisposing factors that significantly increased the incidence of root fracture.     

Structural resistance in immature teeth using root reinforcements in vitro

Abstract –  The purpose of this study was to evaluate in vitro the efficacy of root reinforcements by light-cured composite resin or zirconium fiber post in simulated immature non-vital teeth. Fifty-six bovine incisors teeth were used for this study. The crown of each tooth was removed in the medium third to obtain a standard length of 30 mm. The specimens were divided into four groups ( n  = 14): G1) the root canals were instrumented and enlarged to simulate immature non-vital teeth and were reinforced with a light-cured composite resin using a translucent curing post (Luminex system); (G2) the specimens were instrumented, enlarged and they received root reinforcement with zirconium fiber post; G3 (positive control): they received similar treatment to the G1 and G2 groups, but did not receive root reinforcement; G4 (negative control): the roots were not weakened and did not receive reinforcement. Every tooth was submitted to compressive force using an Instron testing machine with an angle of 45° at a speed of 1 mm min⁻¹ until the fracture. The results showed a markedly increased resistance to fracture in the G1 and G2 ( 122.38 and 122.08 kgf, respectively). Among the results of G1 and G2 there was not any significant difference (P > 0.05) but they were significantly different from the control groups (P < 0.05). The conclusion is that the use of root reinforcements with zirconiun fiber post or composite resin can increase significantly the structural resistance of the weakened teeth, decreasing the risk of the fracture.     

纤维桩表面处理对其修复后牙根抗折裂强度的影响

目的评价不同的纤维桩表面处理方法对纤维桩修复后牙根抗折裂性能的影响。方法将24根纤维桩平均分为喷砂组、过氧化氢酸蚀组和未处理组（对照组）,分别将其黏固于24颗经过桩道预备的离体牙内,树脂成核,然后行金属全冠修复。模拟口腔环境将样本进行冷热循环和循环加载,然后置于电子万能实验机上测试其抗折裂强度,记录样本折裂时的力值以及折裂模式。结果纤维桩表面处理组的牙根抗折裂强度均大于未处理组（P<0.05）,而喷砂和过氧化氢处理组之间的牙根抗折裂强度的差异无统计学意义（P>0.05）。各组的折裂模式均以根颈1/3处折裂为主。结论喷砂和过氧化氢酸蚀处理均能提高纤维桩加树脂核修复后的牙根的抗折裂强度。