为探讨口腔修复学本科教育实验教学内容改革,使其更好地与当前口腔修复学临床诊疗相适应,通过调查我校口腔专业五年制、七年制本科生对实验课教学内容的反馈,根据当前临床诊疗过程的实践需要,着眼于本科生教学大纲、执业医师实践考试和临床基本技能要求,就合理安排和重新分布实验课程的教学内容提出几点思考,为构建适用于临床技能发展的口腔医学本科生口腔修复专业课程的实验课教学体系提供思路.

PURPOSE:To investigate the bond strength and durability of a novel dual-curing composite cement to zirconia under different curing conditions.MATERIALS AND METHODS:Zirconia plates of different thickness (0.5, 1, and 2 mm) were bonded with either a novel dual-curing composite cement (Panavia V5, PV5, Kuraray Noritake) or a traditional one (RelyX Ultimate, RUL, 3M Oral Care; Multilink Automix, MLA, Ivoclar Vivadent), in light-, self-, or dual-curing mode. Bonded specimens were subjected to shear bond strength (SBS) tests after 24 h of water storage or after artificially aging by 20,000 thermal cycles plus 150 days of water storage. The degree of conversion (DC) of the composite cements under different curing conditions was measured by Fourier transform infrared (FTIR) spectroscopy. The irradiance and translucency of the zirconia plates of different thickness were also investigated.RESULTS:The irradiance and translucency of zirconia decreased significantly with increasing thickness (p = 0.00). Both before and after aging, SBS of PV5 in self-curing mode was significantly higher than that of RUL (p = 0.07 before aging and 0.02 after aging) and MLA (p = 0.00 both before and after aging). However, for the three composite cements, light- and dual curing yielding the same SBSs for a constant Y-TZP thickness (p > 0.05). The FTIR analysis showed that, for all three dual-curing composite cements examined in this study, the mean DC values obtained in dual-curing mode were lower than those achieved in light-curing mode (p = 0.00 for PV5, RUL, and MLA). For RUL and MLA, lower mean DC values were obtained in self-curing than dual-curing mode (p = 0.00 for both RUL and MLA), while the DC values of PV5 showed no significant difference between self-curing and dual-curing mode (p = 0.33).CONCLUSION:When the photoactivation time is 60 s and the thickness of the zirconia restoration is less than 2 mm, it is safe to use the two traditional dual-curing composite cements RUL and MLA and PV5 for bonding zirconia. However, when the light exposure time is insufficient, PV5 provides improved bond strength and durability to zirconia.

Purpose To determine and compare the effects of tribochemical silica coating and alumina-particle air abrasion on 3 mol% and 5 mol% yttria-stabilized tetragonal zirconia polycrystals (Y-TZP). Materials and methods Two different 3Y-TZP samples (Lava Plus, 3M Oral Care; Ceramill Zolid, Amann Girrbach) and one 5Y-TZP sample (Katana Zirconia UTML, Kuraray Noritake) were prepared and treated with alumina-particle air abrasion and a 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP)-containing self-adhesive composite cement or with tribochemical silica coating followed by silanization (n = 30). Resin columns were cemented onto the treated ceramic surfaces to form specimens. After 24-h water storage or aging with 10,000 thermocycles plus 60-day water storage, shear bond strength (SBS) testing was conducted. Surface roughness, surface Vickers hardness, and crystallographic phase analyses were also performed. Results The SBS of tribochemically silica-coated 5Y-TZP before and after aging were 13.8 ± 1.4 and 13.2 ± 1.5 MPa, resp., for Lava Plus (3Y-TZP) 14.4 ± 1.4 and 13.9 ± 1.6 MPa, respectively, and for Ceramill Zolid (3Y-TZP) 14.8 ± 1.1 and 13.9 ± 1.5 MPa, respectively. There was no statistical difference between tribochemical silica coating and alumina air abrasion treatments (p = 0.21) on the bonding performance (SBS) of the 3Y-TZPs and 5Y-TZP (p = 0.25) before and after aging (p = 0.50). After alumina air abrasion, 5Y-TZP showed higher surface roughness (Ra = 1.7 ± 0.1) than did the 3Y-TZPs (Ra = 1.2 ± 0.1 for Lava Plus; Ra = 1.2 ± 0.1 for Ceramill Zolid), while the Vickers hardness was similar among the three materials (p = 0.70). Monoclinic zirconia was not detected in 5Y-TZP irrespective of treatment, with the zirconia being mainly cubic phase. However, the 3Y-TZPs were mainly tetragonal phase with some monoclinic zirconia; the latter increased after being alumina-particle air abraded. Conclusion The bond strength to 5Y-TZP is similar to those of the 3Y-TZPs under the same bonding strategies. Durable bonding can be achieved both by alumina air abrasion combined with a 10-MDP-containing self-adhesive composite cement and by tribochemical silica coating followed by silanization for both the 3Y-TZPs and 5Y-TZP.

Objective To evaluate the bond performance of primers,universal adhesives and self-adhesive resin cements containing methacryloyloxydecyl dihydrogen phosphate (MDP) to zirconia.Methods Two hundred and ten yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) plates were prepared and divided into seven groups according to each of six MDP-containing products and one MDP-free resin cement.Two primers,two universal adhesives and two self-adhesive resin cements were applied on the specimens after these specimens recived alumina air abrasion.The group of MDP-free resin cement was set as control.Each group contained 30 specimens.Y-TZP plates were bonded to resin composite to build resin bonding specimens,and half of these plates were stored in distilled water at 37 ℃ for 24 hours,the other half were stored for 12 months.Shear bond strength (SBS) test and fracture modes analysis were performed.Results The SBS values of all the experimental groups were above 9.51 Mpa,which increased 24-hour values compared to the (5.04±t0.50) Mpa of the control group.Group using one of the self-adhesive resin cement yielded the highest SBS,(11.06±0.84) Mpa.SBS of all groups decreased significantly compared to 24-hour SBS after aging (P ＜ 0.05),however,the SBS values of MDP-containing products groups can still be maintained above 7.44 Mpa.Two self-adhesive cement groups and one of the universal adhesive group maintained higher SBS values,and the values were statistical different from those from the two primer groups (P ＜ 0.05).Conclusions Different MDP-containing products have different effects on the bond durability of zirconia.

目的:观察鼻内镜下鼻丘径路额窦开放联合部分中鼻甲切除术治疗难治性鼻窦炎的临床效果.方法:难治性鼻窦炎患者50例,按治疗方案不同分为对照组和观察组各25例.对照组接受单独的鼻内镜下鼻丘径路额窦开放术治疗,观察组接受鼻内镜下鼻丘径路额窦开放联合部分中鼻甲切除术治疗.采用Lund-Kennedy评分比较两组临床疗效,采用SNOT-20评分比较两组患者生活质量,观察两组术后并发症发生率.结果:治疗前Lund-Kennedy评分对照组为6.08±2.41分,观察组为6.12±2.68分,差异无统计学意义(P＞0.05);治疗后3个月Lund-Kennedy评分对照组为4.04±1.79分,观察组为2.04±1.40分,两组均较治疗前下降,差异均有统计学意义(P＜0.05),但观察组评分较对照组更低,差异有统计学意义(P＜0.05).治疗前SNOT-20评分对照组为38.84±7.53分,观察组为38.56±7.56分,差异无统计学意义(P＞0.05);治疗后3个月SNOT-20评分对照组为22.28±4.65分,观察组为13.20±4.00分,两组均较治疗前下降,差异均有统计学意义(P＜0.05),但观察组评分较对照组更低,差异有统计学意义(P＜0.05).对照组发生并发症4例(16.0％),包括窦口闭锁1例,鼻腔粘连2例,眶周青紫1例;观察组发生并发症2例(8.0％),包括鼻腔粘连1例,眶周青紫1例;两组并发症发生率比较,差异无统计学意义(P＞0.05).结论:鼻内镜下鼻丘径路额窦开放联合部分中鼻甲切除术治疗难治性鼻窦炎临床疗效显著,安全性高,能有效减轻患者症状、体征,改善患者生活质量.

目的 研究体外低温老化处理对一种含氧化锆填料的CAD/CAM复合树脂块的氧化锆晶相、结构及该材料抗弯性能的影响.方法 制备16枚相同尺寸的Lava Ultimate(LU)长条试件,在低温老化(高压灭菌釜内,温度134℃、压力0.2 MPa下持续处理20 h)前后分别对试件进行X射线衍射(XRD)和扫描电子显微镜(SEM)分析,用以评价LU体外低温老化后的晶相及结构稳定性.同时,用万能试验机测试试件的抗弯性能,对数据集进行单因素方差分析,评价其抗弯性能的变化.结果 低温老化前后LU的弯曲强度分别为(185.33±19.22)Mpa和(220.89±20.88)Mpa,低温老化前后的弯曲模量分别为(14.16±0.92)Gpa和(20.93±0.97)Gpa,低温老化处理后均显著提高(P<0.05).X射线衍射图发现LU老化前后氧化锆晶相未发生变化.扫描电镜图发现,LU老化后微观结构更加致密.结论 Lava Ultimate 在低温老化处理下具有良好的晶相、结构及抗弯性能稳定性.

Purpose: This study aimed to evaluate bond durability when applying 2 phosphate ester monomer-containing self-adhesive resin cements alone, versus a combination of phosphate ester monomer-containing primer conditioning plus 2 conventional resin cements requiring primers, to zirconia after different artificial aging methods. Methods: We cemented air-abraded zirconia plates to composite resin cylinders with self-adhesive resin cements (MS; RU) alone or cemented them with traditional resin cements (ZRV; ZVN) after preconditioning with a zirconia primer. A shear bond strength (SBS) test were performed after subjecting them to 19 different aging conditions (n= 15) comprising 30,000x thermocycles, air storage at room temperature (RT), water storage at RT, or at 37 degrees C for 24 h,1 week, 1, 3, 6, and 12 months. Zirconia powders mixed with zirconia primer or 2 self-adhesive resin cements were characterized by X-ray photoelectron spectroscopy. Results: Groups MS and ZVN obtained the highest SBS after all of aging methods. SBS after 6 months of storage was similar to SBS after 24 h of storage, while both were higher than SBS after 1 year of storage. Water storage at 37 degrees C provided higher SBS than RT water storage did. We detected a Zr-O-P bond in both self-adhesive resin cement/zirconia powder mixtures. Conclusions: Application of self-adhesive resin cements alone could be an alternative to pre-conditioning with a zirconia primer followed by the application of conventional resin cements. Formation of Zr-O-P bonds contributed to the bonding improvement of self-adhesive resin cements. Different aging conditions affected SBS values. (C) 2019 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

目的:探讨不同表面处理对二硅酸锂玻璃陶瓷的表面微观形态以及粗糙度的影响.方法:制作相同规格的二硅酸锂玻璃陶瓷片(12 mmm× 15 mm×2 mm),经过厂家推荐的烧结程序完全烧结、常规表面抛光处理后分为对照、喷砂和氢氟酸3组,样本经过表面处理后以表面轮廓仪测量表面粗糙度,并以场发射扫描电镜(scanning electron microscope,SEM)观察表面微观形态.结果:SEM观察显示,抛光陶瓷表面相对平整光滑,而氢氟酸处理后,陶瓷表面基质溶解,暴露出二硅酸锂晶体且相互交叉排列,氧化铝喷砂后陶瓷表面可见不规则浅凹状结构;表面轮廓仪测量结果表明喷砂及酸蚀处理后陶瓷表面粗糙度显著增加(P＜0.05).结论:氧化铝喷砂、氢氟酸酸蚀可以显著增加二硅酸锂玻璃陶瓷的表面粗糙度.

目的 评价一种自粘接树脂水门汀RelyXTM U200与氧化锆陶瓷粘接的强度和耐久性.方法 90枚氧化锆瓷片(Y-TZP)喷砂处理后分别以"使用自粘接树脂水门汀RelyXTM U200(RU组)"和"氧化锆底涂剂处理+使用传统树脂水门汀RelyX Veneer(ZPRV组,对照组)"两种粘接策略制作Y-TZP/树脂水门汀/光固化复合树脂结构的粘接试件.两组试件分别按照以下三种方法进行处理:37℃水储24 h,30000次冷热循环下进行人工老化,37℃水储6个月进行人工老化,随后测试试件的剪切粘接强度,分析断裂模式.按照剪切测试同样的两种粘接策略分别制作双瓷层粘接试件(n=10),以去离子水浸泡,电感耦合等离子体质谱(ICP-MS)测试1、7、14、21、30、60和90 d的磷元素释放量.结果 两种粘接策略提供了类似的氧化锆陶瓷与树脂间的粘接强度(P=0.841),这一粘接强度在老化处理后均降低(P<0.05),并且老化处理后各组试件的粘接断裂模式所占比例增加.RU组可获得与ZPRV组相等或更高的粘接耐久性.ICP-MS测试仅在Ctr-RU(单纯树脂水门汀RelyXTM U200,对照组)、RU和ZPRV中检测到了磷元素的释放,随浸泡时间的延长,磷元素的释放呈现一定的增加.结论 RelyXTM U200树脂水门汀在无需底涂剂处理的条件下用于氧化锆陶瓷粘接可获得较好的粘接强度和粘接耐久性.

OBJECTIVES:This study aimed to investigate the effects of hydrothermal aging, thermal cycling, and water storage on the mechanical properties of a machinable resin-based composite containing nano-zirconia fillers. MATERIALS AND METHODS:A machinable resin-based composite containing nano-zirconia fillers (Lava Ultimate, LU) and a resin-based composite with a similar resin matrix-to-filler ratio but without zirconia fillers (Tetric N-Ceram, TNC) were prepared into bars and assigned into four groups based on the type of aging treatment (hydrothermal aging, thermal cycling, water storage, or no aging). The phase transformations of the zirconia fillers in LU after aging were evaluated by X-ray diffraction. The flexural strength, Weibull modulus, flexural modulus, and Vickers hardness of each group were investigated. The fracture surface morphologies of both resin-based composites before and after aging were observed by a scanning electron microscopy (SEM). RESULTS:Only Tetragonal zirconia was detected in the LU samples. Both before and after aging, the flexural strength, flexural modulus, and Vickers hardness values of LU were significantly higher than those of TNC (p < 0.05) with the exception of the flexural modulus of LU, which showed no difference with that of TNC after water storage (p = 0.68). Hydrothermal aging, thermal cycling, and water storage had no significant effects on the surface Vickers hardnesses of LU or TNC (p > 0.05). Hydrothermal aging significantly improved the flexural strength of LU (p = 0.00). Thermal cycling (p = 0.00) and water storage (p = 0.00) significantly decreased the flexural strength of LU. The flexural strength of TNC was not decreased by hydrothermal aging (p = 0.82) or water storage (p = 0.36), while it was decreased by thermal cycling (p = 0.00). The hydrothermal aging group of LU exhibited the highest Weibull modulus. CONCLUSIONS:The machinable resin-based composite containing nano-zirconia fillers provides superior flexural strength, flexural modulus, and Vickers hardness compared to the direct-filling resin-based composite with a similar resin matrix-to-filler ratio, although it fails to provide better aging resistance.

目的 探讨两类光固化树脂基材料在40 s光照下的聚合情况.方法 采用傅立叶转换红外光谱分析法(FTIR)探讨两种光固化复合树脂Filtek Z100、Filtek Z350及一种光固化树脂水门汀Relyx Veneer、一种双固化树脂水门汀Nexus 3(NX3)光照40 s并放置24 h及两周后聚合度的变化.结果 红外光谱结果发现40 s光照后两类树脂基材料双键转化度仅达到50％左右,随着放置时间增加树脂聚合度会有所提高;放置相同时间时,复合树脂中Z350聚合度高于Z100,树脂水门汀中光固化材料Relyx Veneer聚合度高于双固化树脂水门汀NX3.结论 40 s光照时间不足以使树脂基材料达到完全聚合的效果.

Objectives. To examine effectiveness of pre-silanization in improving bond performance of multipurpose products such as universal adhesives or self-adhesive resin cements to silica based ceramics. Methods. The present study investigated reactions between silanol groups of gamma-methacryloxypropyltrimethoxysilane (gamma-MPS) and silica, dehydration self-condensation of gamma-MPS, and condensation polymerization between gamma-MPS and 10-methacryloyloxydecyl dihydrogen phosphate (10-MDP) by using thermodynamic calculations. Shear bond strength (SBS) tests were used to evaluate the influence of pre-silanization on resin bonding when a silane-containing universal adhesive, a silane-unknown universal adhesive, or two self-adhesive resin cements were applied for bonding lithium disilicate to resin. In addition, reactions between silane and lithium disilicate were analyzed using X-ray photoelectric spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Results. Acquired thermodynamic data indicated formation of siloxane between gamma-MPS and silica. However, self-condensation of gamma-MPS and reaction between gamma-MPS and 10-MDP consumed the silanol. Pre-silanization enhanced SBS for self-adhesive resin cements or universal adhesives when applied for bonding silica-based ceramics. Thermocycling and aging decreased SBS in most groups. XPS and FTIR supported formation of siloxane between the employed silane coupling agent and two universal adhesives and lithium disilicate. Significance. Pre-silanization is beneficial in further enhancing bond performance of universal adhesives or self-adhesive resin cements to silica-based ceramics. (C) 2019 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

目的:评价氩气、30％ H2O2和50％ H2O2等离子体对基托树脂表面生物膜内白色念珠菌的杀灭效果.方法:将甲基丙烯酸甲酯材料制作成大小为9 mm×9 mm×2 mm试件68块,在试件表面培养48 h白色念珠菌生物膜.取64块试件随机分为对照组和15个处理组(n=4),对照组不做处理,氩气等离子体分别处理60、120、180、240、300 s,30％ H202和50％ H202等离子体分别处理20、40、60、80、100 s.处理后洗脱、系列稀释、涂板,采用菌落形成单位计数法评估杀菌效果.剩余4块试件:1块作为对照组,其余3块分别用氩气、30％ H2O2和50％H2O2等离子体处理300 s,扫描电镜观察细胞表面损伤.结果:氩气等离子体处理300 s、30％ H202等离子体处理100 s、50％ H2O2等离子体处理80 s,杀灭率均超过99.99％.电镜下处理后的细胞膜表面粗糙,有孔洞.结论:氩气、30％ H2O2和50％H2O2等离子体均能有效杀灭生物膜内的白色念珠菌.

目的 分析Lava Plus高透氧化锆全瓷材料在钴铬金属、遮色钴铬金属、贵金属、遮色贵金属4种桩核背景下应用的颜色变化.方法 制作颜色分别是2M2、3M2的高透氧化锆瓷片,分别以钴铬金属、遮色钴铬金属、贵金属、遮色贵金属材料和2M2、3M2本色氧化锆瓷块作为背景,采用3nh色差仪测量不同背景下瓷片中央区域的L、a、b值,进行多因素方差分析及LSD两两比较,并根据公式计算和比较色差值ΔE.结果 颜色、底色及颜色和底色的交互作用对L、a、b值影响具有统计学意义(P=0.000).钴铬金属组在4种底色中L、a、b均值最低,遮色组L、a、b均值高于非遮色组.除2M2和3M2组的Δa值差异没有统计学意义外(P=0.252),颜色、底色及其交互作用对氧化锆瓷片色差值ΔL、Δa、Δb、ΔE的影响均具有统计学意义(P=0.000).钴铬金属组ΔE均超出临床可接受范围(ΔE≥5.5).遮色钴铬金属、遮色贵金属、贵金属组均不超过肉眼可识别范围(ΔE<2.6).结论 钴铬金属桩核对Lava Plus高透氧化锆颜色具有显著性影响.但Lava Plus高透氧化锆对其他背景有较好的遮色效果.

Objectives: This study aimed to evaluate the effects of different firing cycles on surface hardness, fracture toughness, and roughness of lithium disilicate glass-ceramic, as well as their bond strength to resin. Materials and methods: A total of 320 polished lithium disilicate glass-ceramic plates were assigned to four main groups (n = 60) to receive one, two, three, or four firing cycles, respectively. Ceramic plates of the four groups were conditioned with HF acid followed by silanization. The pre-treated ceramic plates were cemented with composite resin cylinders using conventional or self-adhesive resin cements to build bonded specimens, and submitted to shear-bond-strength (SBS) testing after water storage for 24 h or 3 mo at 37 degrees C. The ceramic received different firing cycles after polishing or HF etching was observed using a scanning electron microscope, and their surface roughnesses were determined by a profilometer. The surface Vickers hardness, fracture toughness, and related Weibull analysis results of the polished ceramics after undergoing different firing-cycle times were compared. Results: One sintering significantly increased fracture toughness of lithium disilicate glass-ceramic; however, multiple firing cycles failed to increase it further. Weibull analysis revealed a significant difference in terms of structural reliability among the specimens receiving 0-4 firing cycles. Specimens that received no firing cycle showed the highest surface hardness. Multiple firing cycles had no significant influence on the surface Vickers hardness and surface roughness. HF etching increased surface roughness, and the roughened surface improved the resin SBS of lithium disilicate glass-ceramic. Multiple firing cycles had no significant effect on surface roughness. Furthermore, multiple firing cycles and 3-mo water storage had no significant effect on the SBS. Conclusions: The mechanical properties of lithium disilicate glass-ceramics would be partially affected by multiple firing cycles, while their resin bonding would not be.

Purpose This study compared bond strength, durability, and mechanical properties of luting cements for bonding zirconia: a resin-modified glass ionomer cement (RMGIC), a conventional composite cement, and two self-adhesive composite cements. Materials and methods The air-abraded zirconia specimens were assigned to 12 groups (n = 30) to prepare bonded specimens. Classification was based on the pre-conditioning selection: none; primers containing 10-methacryloyloxydecyl dihydrogen phosphate (MDP); universal adhesives containing MDP. Further classification was done according to the type of luting cement: RMGIC; conventional composite cement; MDP-free self-adhesive composite cement; MDP-containing self-adhesive composite cement. The shear bond strength (SBS) was measured after 24 h of water storage or aging with 20,000 thermocycles plus an additional 60 days of water storage at 37°C. The elastic modulus and three-point bending strength were determined, and a related Weibull analysis of the four luting cements was performed. Results The choice of luting cement and aging significantly affected the SBS. Aging decreased the SBS in most groups, except for those that used MDP-containing primers plus conventional composite cements. RMGIC had SBS (before and after aging) that were similar to the MDP-free self-adhesive composite cement. Use of MDP-containing products prior to conventional composite cements provided the highest initial SBS. However, pre-conditioning with MDP-containing products failed to increase the SBS of RMGIC. RMGIC showed lower elastic modulus and three-point bending strength than did the three composite cements. Conclusions RMGIC is an alternative to composite cements for luting zirconia restorations. Conditioning with a primer containing MDP combined with conventional composite cement is more reliable.

The aim of this study was to assess insulin-like growth factor binding protein-6 (IGFBP-6) expression, and its potential value as a prognostic indicator of survival in patients with head and neck cancer (HNC). Quantitative realtime polymerase chain reaction (qRT-PCR) and immunohistochemistry analyses were used to determine IGFBP-6 mRNA and protein expression, respectively, in HNC. The correlations between IGFBP-6 expression levels and clinical characteristics or prognoses were determined via statistical analyses. IGFBP-6 mRNA and protein levels were significantly higher in HNC tissues than in normal adjacent tissues (P<0.000 1). High IGFBP-6 expression in cancer tissues was significantly associated with sex (P=0.013), tobacco consumption (P=0.021), tumor location (P=0.001), histopathological grade (P=0.030), T stage(P=0.04), and tumor classification. IGFBP-6 expression in buccal squamous cell carcinoma (BSCC) tissues was correlated with laryngeal squamous cell carcinoma (LSCC) development (P=0.001) but not tongue squamous cell carcinoma (TSCC) development (P=0.355). High IGFBP-6 expression (P=0.001), histopathological grade (P=0.020), T stage (P=0.007), lymph node metastasis (P=0.001), and pTNM stage (P=0.001) were identified as significant prognostic factors for survival. Kaplan-Meier survival curves demonstrated that patients with high IGFBP-6 levels or stage Ⅲ + Ⅳ cancer exhibited significantly shorter survival times than patients with low IGFBP-6 levels or stage Ⅰ + Ⅱ disease. Our findings provide the first evidence that high IGFBP-6 expression is associated with poor prognosis in HNC.

Objective The combination of phosphate ester monomers PENTA(Dipentaerythritol penta?acrylate phosphate)and dental Y?TZP(Yttria?stabilized tetragonal zirconia polycrystals)was proved by chemical method to explain why PENTA was able to en?hance the bonding affinity between resin and zirconia. Methods 5%,10%,15%,20% experimental PENTA primers were prepared and then conditioned with Y?TZP powders.Powders were washed repeatedly by acetone to wipe off the dissociative component and tested by FTIR(fourier transform infrared spectroscopy)and TG(thermogravimetric analysis).FTIR analysis focused on the changes between 10% PENTA in acetone solvent and the powders conditioned with different experimental primers. Peak fitting was carried out according to second derivations and the residual. The Y?TZP powder without primers was set as the control group in TG test. Result Two differ?ent peak fitting methods both indicated that the vibration of the P?O bond went towards lower wavenumber after PENTA conditioned with Y?TZP powder. TG test showed that PENTA with higher concentration reacted with Y?TZP more completely. Conclusion The chemical reaction between PENTA and Y?TZP relies on the phosphate group.

OBJECTIVE:This study evaluated the influence of alkaline coating of nano-zirconium hydroxide on resin bonding of 10-methacryloxy decyldihydrogen phosphate (MDP)-conditioned zirconia.METHODS:A total of 140 yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) plates were prepared and sandblasted with alumina particles, and then subjected to different surface treatment. Resin bonding specimens were prepared with a MDP-free resin cement and tested for shear bond strength (SBS). X-ray photoelectron spectroscopy (XPS) was used to investigate the formation of chemical bond on the surface of Y-TZP treated successively with nano-zirconium hydroxide coating and MDP containing primer.RESULTS:The two alkaline coatings increased the 24 h SBS compared to control groups, and groups using nano-zirconium hydroxide coating yielded higher SBS. After thermocycling, no statistical difference was observed between groups, but SBS decreased significantly compared to the 24 h SBS (P<0.05). XPS analysis detected -OH bond on the surface of Y-TZP treated with nano-zirconium hydroxide coating, and -P-O-Zr bond was detected on the surface of Y-TZP treated with nano-zirconium hydroxide coating and MDP-containing primer.CONCLUSIONS:Alkaline coatings improved the bonding of resin to zirconia conditioned with MDP-containing primers.

Objective To evaluate the effect of different types of titanate coupling agents ( KR-TTS,KR-12,KR-38S) applied alone or in combination with phosphate ester monomer ( MDP or PENTA) on bond strength between resin composites and dental zirconia ce-ramics . Methods 130 pieces of ceramic plates were sandblasted and randomly divided into 13 groups based on the surface treatment to be applied:group Kt , K1 K3 , the self-formulated primers contained only one type of titanate coupling agent;group H-M, the self-for-mulated primers, combining with the phosphate ester monomer ( MDP or PENTA) respectively, contained the titanate coupling agent;the positive control groups included the MDP (group M), PENTA (group P) self-formulated primers and commercialization MDP-con-taining primer Z-Prime Plus ( group Z);the ceramic plates in the negative control group ( group C0 ) received no further surface treat-ment. Then adhesive specimens were produced and after immersed in water for 24h, shear bond strength(SBS)and modes of failure were determined. Results The shear bond strength of each type of titanate coupling agent, whether used alone or combined with phos-phate ester monomer(MDP or PENTA), was lower than that of the phosphate ester monomer MDP or PENTA and Z-Prime Plus(P<0.05) . Simultaneously, the shear bonding strength of partial groups applying titanate coupling agents was even lower than that of the sandblasted group. Conclusion Application of titanate coupling agent negatively affects bonding strength between zirconia and resin.