干燥和湿润环境下不同牙本质粘接剂的微拉伸粘接强度比较

目的 应用6种不同类型牙本质粘接剂,比较其粘接试样在干燥和湿润测试环境下的微拉伸粘接强度,并分析产生差异的原因。方法 选择人离体无龋第三磨牙24颗,暴露面牙本质,将试样随机均分为6组,分别使用6种粘接剂（Prime ＆ Bond NT、Contax、Clearfil SE Bond、Adper Prompt、Clearfil S3 Bond和i Bond）和一种复合树脂制作牙本质-复合树脂粘接体,然后纵向片切制备横截面积约0.8 mm²的微拉伸试样,每种粘接材料的拉伸试样再分成3个亚组（每个亚组n=20）：A组（试样粘接界面保持湿润）、B组（试样在空气中干燥2 h后测试）、C组（试样在空气中干燥24 h后测试）,测试微拉伸粘接强度,最后扫描电镜观察断裂模式。结果 i Bond处理的A组与B、C组粘接强度差异无统计学意义（P>0.05）,其余5种粘接剂的A组粘接强度均低于B、C组（P<0.05）。断裂模式均以界面破坏为主,与试样干湿状态无关。结论 干燥环境下所测得牙本质粘接剂的微拉伸粘接强度值高于湿润环境下所测得的强度值。     

All-on-4即刻种植与延期种植对牙列缺失患者恢复情况及对PES评分和炎症因子水平的影响研究

目的 研究All-on-4即刻种植与延期种植对牙列缺失患者恢复情况及对PES评分和炎症因子水平的影响。方法 采取前瞻性研究,选择自2018年1月到2019年1月期间在本院进行治疗的牙列缺失患者120例作为研究对象,平均年龄为（45.67±3.09）岁,使用随机数字表将以上患者随机分为两组,每组60例,其中观察组采取All-on-4即刻种植治疗,对照组采取延期种植,比较两组患者术后12个月的治疗效果、PES评分、牙槽嵴骨的吸收高度、主观满意度、龈沟液炎性反应水平、并发症之间的差异。结果 观察组患者的总有效率显著高于对照组（P< 0.05）;经过治疗后,两组患者的PES评分均显著改善,且观察组患者的PES评分高于对照组（P< 0.05）;观察组患者的附着高度、咀嚼功能、整体美观显著优于对照组,牙槽嵴骨的吸收高度显著低于对照组（P< 0.05）;两组患者的IL-4、IL-10、INF-γ以及TNF-α水平显著下降（P< 0.05）,且观察组患者的IL-4、IL-10、INF-γ以及TNF-α水平显著低于对照组（P< 0.05）;两组患者的并发症牙龈撕裂、舌侧骨板骨折、术后干槽症之间的差异不存在统计学意义（P> 0.05）。结论 牙列缺失患者的治疗中采取All-on-4即刻种植修复,患者的PES评分显著改善,炎症因子水平显著下降,治疗效果显著。     

矿化胶原膜浸提液对MG-63人骨肉瘤细胞分化相关基因表达的影响

目的 研究新型矿化胶原膜对MG-63人骨肉瘤细胞（简称：MG-63细胞）成骨分化相关基因表达的影响。方法 将MG-63细胞与新型矿化胶原膜浸提液（实验组）共培养,以市售的胶原膜（Bio-gide）浸提液作为同类产品对照组,以不加材料的细胞培养液为空白对照组,采用荧光实时定量PCR法检测碱性磷酸酶（ALP）、I型胶原（COL I）、骨保护素（OPG）和骨钙素（OC）mRNA表达水平;采用SPSS 17.0软件对数据进行统计学分析。结果 在ALP与OPG mRNA相对表达量检测中,3组成骨细胞的表达量差异无统计学意义（P> 0.05）;在COL I与OC基因相对表达量检测中,14天时Bio-gide组和矿化胶原膜组表达均明显上调,与空白对照组相比,差异均具有统计学意义（P< 0.05）,而Bio-gide组和矿化胶原膜组相比,差异无统计学意义（P> 0.05）。结论 矿化胶原膜和Bio-gide膜的浸提液均可上调MG-63细胞COL I和OC的基因表达,在一定程度上促进了成骨细胞的分化。     

不同根管冲洗液和冲洗方法对粪肠球菌清除作用的体外研究

目的 比较不同冲洗液和冲洗方法对根管内粪肠球菌的清除效果。方法 建立120颗人完整单根管前磨牙粪肠球菌感染根管模型,随机分组,分别采用不同冲洗液(0.9% NaCl,0.5% NaClO,3% NaClO)及冲洗方法(注射针头冲洗,超声荡洗,RinsEndo系统处理,超声荡洗协同RinsEndo系统联用)进行根管清理。无菌吸潮纸尖取样,平板菌落计数法计算CFU值,计算细菌清除率,运用SPSS 22.0软件进行统计分析,P<0.05时差异具有统计学意义。结果 使用0.9% NaCl及0.5% NaClO冲洗液时,注射针头冲洗组细菌清除率明显低于超声荡洗及RinsEndo系统处理组(P<0.001);使用3% NaClO冲洗液的各组不同的冲洗方法,细菌清除率的差异无统计学意义(P=0.556)。而无论采用哪种冲洗方法,3% NaClO溶液的细菌清除效果均优于0.5% NaClO溶液和0.9% NaCl溶液(P<0.001)。结论 不同根管冲洗液在一定程度上会影响根管冲洗方法对根管内粪肠球菌的清除效果。     

西帕依固龈液联合米诺环素对局限型侵袭性牙周炎牙周致病菌的作用分析

目的 评价西帕依固龈液和米诺环素联合用药对局限型侵袭性牙周炎患者唾液中伴放线杆菌（A.a）、牙龈卟啉单胞菌（P.g）和中间普氏菌（P.i）检出率和相对含量的影响。方法 90例局限型侵袭性牙周炎患者随机分为西帕依固龈液组、米诺环素组及联合用药组3组,每组30例。治疗前1周和治疗后1个月分别采集研究对象唾液,进行DNA提取及PCR反应,分析患者唾液中A.a、P.g和P.i的检出率和相对含量。结果 3组用药后A.a、P.g和P.i检出率与用药前差异无统计学意义（P>0.05）,但相对含量有所降低,差异有统计学意义（P<0.05）;与米诺环素组相比,西帕依固龈液组P.i的相对含量更低（P<0.05）;与米诺环素组和西帕依固龈液组相比,联合用药组A.a、P.g、P.i的相对含量更低（P<0.05）。结论 西帕依固龈液和米诺环素联合用药对牙周炎患者唾液中A.a、P.g和P.i检出率的影响甚微,但能抑制其相对含量,联合用药比单独用药的抑制效果好。     

Cavicide消毒液对口腔硅橡胶印模的消毒效果

目的 探讨Cavicide消毒液对口腔硅橡胶印模消毒效果及尺寸稳定性的影响。方法 将加成型硅橡胶印模材料制成55 mm×30 mm×10 mm大小、表面光滑平整的试样,单面划一条标记线段,表面涂布失去活性的15％牛血清以模拟口腔唾液,用无菌棉签分别涂布金黄色葡萄球菌、血链球菌和白色念珠菌3种细菌悬液0.5 ml/100 cm³,随机分成5组,一组不加任何消毒剂（对照组）,其他4组实验组分别为二氧化氯浸泡组、戊二醛浸泡组、cavicide浸泡组和cavicide喷涂组,比较分析各组抑菌率,并在显微镜下测量标记线段的长度变化。结果 对3种细菌抑菌率的结果显示： Cavicide浸泡组抑菌率最高,Cavicide喷涂组抑菌率次之,与其他2实验组比较差异有统计学意义（P<0.05）。二氧化氯浸泡组与戊二醛浸泡组之间差异无统计学意义（P>0.05）; Cavicide浸泡组和喷涂组标记线段长度几乎未见变化,组间差异无统计学意义（P>0.05）,二氧化氯浸泡组和戊二醛浸泡组标记线段长度明显变长,与Cavicide浸泡组和喷涂组比较,差异有统计学意义（P<0.05）。结论 Cavicide消毒液对口腔硅橡胶印模消毒效果较好,具有较高的抑菌率,且对口腔硅橡胶印模尺寸稳定性影响小,值得临床推广应用。     

康复新液对种植体周围炎疗效的观察

目的 观察康复新液对种植体周围炎的治疗效果。方法 选择种植完成1年以上的患有种植体周围炎的60名患者的60个种植体,经过基础治疗（龈上、龈下洁治,牙周双氧水冲洗）后随机分为3组,分别为A组（康复新液+明胶海绵组：康复新液浸润明胶海绵置入牙周袋内,每周一次）、B组（康复新液组：康复新液冲洗,每周一次）和C组（对照组：生理盐水冲洗组,每周一次）,1个月后,检查各组治疗前后的牙周探诊深度（PD）、牙龈出血指数（SBI）和菌斑指数（PLI）,比较各组的疗效。结果 各组基线时PD、SBI和PLI值之间没有差异（P>0.05）。经过1个月的相应治疗后,PD、SBI和PLI值均有明显改变,与基线时的差异有统计学意义（t>t_0.01,P<0.01）,说明治疗有效;各试验组间两两比较：PD、SBI值,A组与B组,B组与C组间差异没有显著性意义（P>0.05）,但A组与C组比较,差异有统计学意义（P<0.05）。PLI值A、B、C 3组间差异没有统计学意义（P>0.05）。结论 康复新液对种植体周围炎的治疗有一定疗效,但其作用效果和其用药方法有关。     

聚酰亚胺共混改性增强义齿基托材料的力学性能研究

目的 研究聚酰亚胺共混改性聚甲基丙烯酸甲酯义齿基托树脂的力学性能。方法 对自行合成的聚酰亚胺（添加质量百分比分别为0,0.4%,0.6%,0.8%,1%）与PMMA义齿基托树脂共混得到的改性基托树脂进行三点弯曲强度试验、断面形态扫描电镜观察和冷热循环试验。结果 聚酰亚胺改性基托树脂抗弯强度在适当共混配比（0.6%）下可达（99.84±3.07）MPa,显著高于未改性树脂的抗弯强度（87.95±5.01）MPa,提高13.5%（P<0.05）。经过冷热循环后其增强效果依然显著（P<0.05）。结论 添加一定量的聚酰亚胺共混改性PMMA基托树脂能获得理想的增强效果。     

不同烧结温度的钛硅涂层对钴铬合金耐腐蚀性能的影响

目的 研究不同烧结温度下的钛硅(TiSi)涂层对牙科软质钴铬合金(CoCr) 耐腐蚀性能的影响。方法 选用临床常用的软质钴铬合金,制作成10mm×10mm×1mm 规格的试件18 件,将试件随机分成A、B、C 3 组(n=6),在B、C 组试件表面运用溶胶-凝胶法涂覆钛硅薄膜,分别设定900℃和1000℃的烧结温度。将A、B、C 组试件分别浸于37℃乳酸/NaCl 溶液中7 天,然后利用失重法计算材料的腐蚀速度,并运用等离子体发射光谱仪(ICP-AES) 对溶液进行分析,以获得3 种试件离子析出量的差异。结果 B、C2 组试件间腐蚀速度没有显著性差异(P>0.05),但都低于A 组试件。离子析出量分析显示,B、C 2 组试件的Co、Cr、Ni 及总的离子析出量均少于A 组试件(P<0.05),B 组试件的Co、Cr、Si 及总离子析出量显著高于C 组试件(P<0.05)。结论 钛硅涂层可显著提高软质钴铬合金的耐腐蚀性能,1000℃获得的钛硅涂层抗蚀性能优于900℃。     

iRoot BP Plus用于外伤露髓年轻恒牙活髓切断术对牙齿变色率及根管钙化的影响

目的 研究iRoot BP Plus用于外伤露髓年轻恒牙活髓切断术对牙齿变色率及根管钙化的影响。方法 选取2018年1月至2020年6月于本院行活髓切断术的82例患儿,随机分为对照组(使用MTA盖髓材料）和观察组(使用iRoot BP Plus盖髓材料）各41例,随访1年,比较两组不同时间的手术疗效、根管钙化和牙齿变色情况,以及手术时间、肿胀时间和疼痛持续时间、牙齿功能和美观度,并记录两组患儿术后并发症。结果 两组术后3个月、末次随访的疗效差异无统计学意义(P>0.05）;观察组肿胀时间、术后疼痛持续时间短于对照组(P<0.05）;观察组的舒适、固定和美观评分高于对照组(P<0.05）;术后6个月及末次随访观察组的根管钙化和牙齿变色率低于对照组(P<0.05）;观察组的并发症发生率为2.44%,低于对照组的14.63%(P<0.05）。结论 iRoot BP Plus与MTA均能较好地用于外伤露髓年轻恒牙的牙髓切断术,其中iRoot BP Plus能减少根管钙化、牙齿变色情况,应用前景良好。     

垫底材料对深龋近髓磨牙充填后疼痛及术后敏感的影响

目的 比较玻璃离子水门汀与流动树脂垫底对深龋近髓磨牙充填后的疼痛及术后敏感性。方法120颗深龋近髓磨牙，随机分为对照组，玻璃离子水门汀组和流动树脂组，每组40颗患牙。对照组采用dycal护髓，玻璃离子水门汀组采用dycal护髓和玻璃离子水门汀垫底，流动树脂组采用dycal护髓和流动树脂垫底，酸蚀粘接后，3组上层均加压充填3M ESPE Filtek^TM P60复合树脂。分别于修复后1天，1周，1个月，3个月采用疼痛程度标尺(Visual Analog scales,VAS)记录自觉疼痛程度，采用Ryge评价标准记录对压缩空气刺激的敏感性。结果 术后1天、1周、1个月和3个月，对照组与两个实验组之间自觉疼痛程度上差异有统计学意义(P<0.05)，各观察期两实验组之间自觉疼痛程度差异无统计学意义(P>0.05)。术后1天和1周，3组之间的术后敏感发生率差异无统计学意义(P>0.05)，术后1个月和3个月，玻璃离子水门汀组和流动树脂组与对照组之间差异有统计学意义(P<0.05)，而玻璃离子组与流动树脂组之间差异没有统计学意义(P>0.05)...     

Influence of proximal box elevation on bond strength of composite inlays

Objectives

The objective of the present study was to evaluate the influence of proximal box elevation on microtensile bond strength (mTBS) of composite inlays to the proximal box floor, using either a total-etch or a self-adhesive resin cement.

Materials and methods

Twenty-five human molars were selected, and a class II OM (inlay) cavity preparation was performed in each tooth. Cavities were randomly assigned into four experimental groups, according to the location of the proximal cervical margin (located 1 mm below cementoenamel junction (CEJ), or with proximal box elevation with composite resin) and the resin cement used for luting (a total-etch resin cement RelyX ARC or a self-adhesive resin cement G-Cem). After 1-week water storage, samples were subjected to mTBS test. Results were analyzed by Kruskal–Wallis and Mann–Whitney U tests (p < 0.05).

Results

Kruskal–Wallis revealed statistically significant differences among experimental groups (p = 0.007). Both resin cements showed similar bond strength values when cervical margin was located below CEJ. The proximal box elevation improved the bond strength of composite inlays for both resin cements. However, only for G-Cem was this improvement statistically significant.

Conclusions

The proximal box elevation improved the bond strength attained by G-Cem resin cement. For RelyX ARC, the position of the cervical margin did not affect composite inlays bond strength.

Clinical relevance

Proximal box elevation does not decline bond strength of composite inlays to the proximal floor when a total-etch or a self-adhesive resin cement is used.

     

The effects of height and surface roughness of abutments and the type of cement on bond strength of cement-retained implant restorations

Objectives: To evaluate the effects and interactions between cement type, abutment height and surface roughness on bond strength of cemented implant restorations. Materials and methods: One hundred and sixty metal copings were fabricated and divided into 16 groups of 10 samples each. Copings were cemented on 4 and 6 mm height Alfa‐Gate^® abutment, using four types of cements: zinc phosphate (ZNP), glass ionomer (GI), and zinc oxide eugenol (ZOE) with or without 15% vaseline. Copings were removed using a universal testing machine and bond strengths were recorded. All abutments were sandblasted with 50 μm aluminum oxide and the experiment was repeated. Results were analyzed using univariate analysis, Games–Howell, and Bonferroni's pairwise comparisons tests at P≤0.05. Results: Bond strengths were significantly different according to cement type, abutment height, and surface roughness (P=0.001). The cement ranking from highest to lowest was: ZNP>GI>ZOE>zinc oxide eugenol with 15% vaseline (ZOEV). An increasing abutment height showed a significant increase in bond strength for permanent cements only (P≤0.05). Sandblasting abutment surface significantly the increased bond strength for all cement except the ZOEV at 4 mm abutment, and for only ZOE and GI cements at the 6 mm abutment (P≤0.05). Conclusions: ZP was the strongest cement and required using one of the variables (height, surface roughness) for maximum bond strength. GI bond strength was increased by both variables but sandblasting was more effective. ZOE required using both variables to be as effective as some of the permanent cement subgroups. ZOEV was the weakest and bond strength was not improved by either variables. To cite this article:
Al Hamad KQ, Al Rashdan BA, Abu‐Sitta EH. The effects of height and surface roughness of abutments and the type of cement on bond strength of cement‐retained implant restorations.
Clin. Oral Impl. Res. 22 , 2011; 638–644
doi: 10.1111/j.1600‐0501.2010.02011.x     

The Effect of Laser Treatment on Bonding Between Zirconia Ceramic Surface and Resin Cement

Abstract

Objective. The purpose of this in-vitro study was to evaluate and compare the effects of different surface treatments and laser irradiation on the shear bond strength of resin cement to zirconia-based ceramic. Material and methods. Forty zirconia core specimens (10-mm diameter, 2-mm thickness) were produced and embedded in the centers of autopolymerizing acrylic resin blocks. Subsequently, specimens were randomly divided into four groups, each containing 10 specimens, for different surface treatment methods. The details of the groups are as follows: Group C, no treatment applied (control); Group SB, bonding surfaces of ceramic disks were airborne particle-abraded with 110-μm alumina oxide particles; Group HF, bonding surfaces of ceramic disks were etched with 9.6% hydrofluoric acid; and Group L, bonding surfaces of ceramic disks were irradiated by a CO₂ laser. A total of 40 composite resin disks were fabricated and cemented with an adhesive resin cement to the specimen surfaces. A universal test machine was used for the shear bond strength test at a crosshead speed of 1 mm/min. Results. The highest shear bond strength values were obtained with Group L (20.99 ± 3.77 MPa) and the lowest values with Group C (13.39 ± 3.10 MPa). Although there was no significant difference between Groups C, HF and SB (P > 0.05), Group L showed a significant difference from all other groups (p < 0.05). Conclusion. All surface treatment methods improved the bond strength between resin cement and the zirconium oxide ceramic surface. CO₂ laser etching may represent an effective method for conditioning zirconia surfaces, enhancing micromechanical retention and improving the bond strength of resin cement on zirconia ceramic.     

Evaluation of some properties of two fiber-reinforced composite materials

Objective. Water sorption, flexural properties, bonding properties, and elemental composition of photopolymerizable resin-impregnated fiber-reinforced composite (FRC) materials (everStick C&B and BR-100) (FPD) were evaluated in this study. Material and methods. Bar-shaped specimens (2×2×25 mm) were prepared for water sorption and flexural strength testing. The specimens (n=6) were polymerized either with a hand light-curing unit for 40 s or, additionally, in a light-curing oven for 20 min and stored in water for 30 days. Water sorption was measured during this time, followed by measurements of flexural strength and modulus. A shear bond strength test was performed to determine the bonding characteristics of polymerized FRC to composite resin luting cement (Panavia-F), (n=15). The cement was bonded to the FRC substrate and the specimens were thermocycled 5000 times (5–55°C) in water. SEM/EDS were analyzed to evaluate the elemental composition of the glass fibers and the fiber distribution in cross section. Results. ANOVA showed significant differences in water sorption according to brand (p<0.05). Water sorption of everStick C&B was 1.86 wt% (hand-unit polymerized) and 1.94 wt% (oven polymerized), whereas BR-100 was 1.07 wt% and 1.17 wt%, respectively. The flexural strength of everStick C&B after 30 days’ water storage was 559 MPa (hand-unit polymerized) and 796 MPa (oven-polymerized); for BR-100, the values were 547 MPa and 689 MPa, respectively. Mean shear bond strength of composite resin cement to the FRC varied between 20.1 and 23.7 MPa, showing no statistical difference between the materials. SEM/EDS analysis revealed that fibers of both FRC materials consist of the same oxides (SiO₂, CaO, and Al₂O₃) in ratios. The distribution of fibers in the cross section of specimens was more evenly distributed in everStick C&B than in BR-100. Conclusion. The results of this study suggest that there are some differences in the tested properties of the FRC materials.     

Assessment of aging characteristics of female condylar trabecular structure by cone-beam computed tomography

Objectives

This study was performed to analyze the aging-related changes of the female condylar bone mineral density (BMD) and trabecular structure by cone-beam computed tomography (CBCT), and determine whether the condylar structure shows obvious changes after menopause.

Methods

The CBCT images of 160 female patients who met the inclusion criteria for the study were collected and divided into four groups by age (20–29 years, 30–39 years, premenopausal, and postmenopausal groups). Computer processing software CT-Analyser (Version 1.15.2.2+; SkyScan, Antwerp, Belgium) was used to measure the condylar BMD and related indexes, namely the bone volume/tissue volume ratio (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular structure model index (SMI), and bone surface area/volume ratio (BS/BV). SPSS 12.0 (SPSS Inc., Chicago, IL, USA) was used to analyze the radiographic findings and statistical differences.

Results

No significant differences were found between the bilateral condyles in each group (P?>?0.05). BV/TV, Tb.N, and Tb.Th of the condyle decreased with age, and the postmenopausal group showed significantly different values for each index compared with the other groups (P?<?0.01). Tb.Sp, SMI, and BS/BV of the condyle increased with age, and the postmenopausal group showed significantly different values for each index compared with the other groups (P?<?0.01).

Conclusions

With increasing age, the female condylar bone volume decreases, the Tb.N and Tb.Th decrease, the gap between the trabecular bone increases, and plate-like trabecular bone gradually transforms into a rod-like form. These changes are much more obvious in postmenopausal women.

     

不同成型片对邻面修复体表面粗糙度的影响

目的 比较使用不同材质成型片的邻面修复体表面粗糙度.方法 选择不同品牌或型号的流体复合树脂、膏体复合树脂以及玻璃离子水门汀充填材料,在体外邻面缺损模型上使用金属和聚酯成型片,模拟II类洞直接充填修复,应用表面粗糙度仪,对各修复体的表面粗糙度进行测量和比较.结果 流体树脂修复体的表面粗糙度Ra值是(0.176±0.063)μm,低于膏体复合树脂(0.456±0.115)μm和玻璃离子水门汀(0.810±0.210)μm,各组间差异具有统计学意义(P<0.001).使用金属和聚酯成型片对树脂类修复体的表面粗糙度影响不大(P>0.05),应用玻璃离子水门汀时,金属成型片的修复体表面更为光滑(P<0.05).结论 临床进行复合树脂邻面洞充填时,可以选择金属或聚酯成型片;而使用玻璃离子水门汀时,建议使用金属成型片.     

The effect of different power outputs of carbon dioxide laser on bonding between zirconia ceramic surface and resin cement

Abstract

Objective. The purpose of this in vitro study was to evaluate the influence of different power outputs of a carbon dioxide (CO2) laser on shear bond strength of resin cement to zirconium dioxide-based ceramic. Materials and methods. Fifty zirconium dioxide core specimens (10 mm diameter and 2 mm thickness) were produced and they were embedded in the centers of auto-polymerizing acrylic resin blocks. Ten specimens served as control and no surface treatment was applied. Subsequently specimens were randomly divided into four groups, each containing 10 specimens for surface treatment with CO2 laser with different output power; laser treated with 2 W (Group 2 W), 3 W (Group 3 W), 4 W (Group 4 W) and finally 5 W (Group 5 W). Fifty composite resin discs were fabricated and cemented with adhesive resin cement to the specimen surfaces. A universal test machine was used for shear bond strength test at a crosshead speed 1 mm/min. Data were statistically analyzed by one-way analyses of variance (ANOVA) with Post-Hoc Tukey tests (α = 0.05). Results. It was found that the shear bond strength values were affected by power outputs of laser (p < 0.05). Highest shear bond strength values were obtained with group 2 W (21.0 ± 2.7). Lowest values were obtained with group 5 W (14.4 ± 1.6). Conclusion. The current study revealed that there was a relationship between laser output power and shear bond strength for zirconium dioxide ceramics. However, output power of the laser and the energy level is a critical factor on micromechanical retention.     

不同根管牙本质表面处理对树脂水门汀粘接强度的影响

目的 比较不同根管牙本质表面处理对树脂水门汀粘接强度的影响.方法 24颗单根管离体前磨牙在釉牙骨质界处截冠后行根管充填,实验随机分为四组:A组为对照组(无表面处理);B组为冲洗处理组(17％EDTA 10ml和5％NaClO10ml联合冲洗根管各30s);C组为酸蚀处理组(35％磷酸酸蚀根管30s);D组为冲洗+酸蚀处理组(先17％EDTA10ml和5％NaClO10ml联合冲洗根管各30s;后用35％磷酸酸蚀根管30s).用PULPDENT树脂水门汀进行粘接.自凝塑料包埋牙根,切割为1 mm厚的试件,并将其按照根管的深度分为根尖、根中、根冠3组,测试其粘接强度.记录数值并进行统计分析.结果 与A组相比,B组、C组和D组冲洗桩道后,三个区段的根管牙本质与树脂水门汀的粘接强度均明显增加,差异有统计学意义(P＜0.01),其中以D组的粘接强度最高,D组根尖段与其他两段间的粘接强度差异有统计学意义(P＜0.01);三组实验组的根中段和根冠段之间差异没有统计学意义(P＞0.05).无论是对照组还是实验组,根尖段牙本质与树脂水门汀的粘接强度均为最低,根冠段最高,且差异具有统计学意义(P＜0.01).结论 (1)采用冲洗处理、酸蚀处理和冲洗+酸蚀处理根管壁均能增强根管牙本质与树脂水门汀的剪切粘接强度;(2)根管部位对根管牙本质与树脂水门汀的剪切粘接强度有影响.     

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.