不同浓度-时间点氢氟酸蚀刻机加工瓷面对瓷与牙釉质的整体粘结抗剪强度的影响

选择３０个氢氟酸（ＨＦ酸）浓度－时间搭配点，测试瓷贴面复合体整体粘结抗剪强度。结果表明：ＨＦ酸蚀刻可增加陶瓷与牙釉质间粘结强度，ＨＦ酸浓度－时间的最佳搭配点为：２．５％－５．０ｍｉｎ；５．０％－５．０ｍｉｎ；７．５％－２．５ｍｉｎ；１０．０％－１．０ｍｉｎ；１５．０％－０．５ｍｉｎ。陶瓷－树脂－牙釉质的粘结破坏形式以混合破坏为主     

氢氟酸蚀刻对Vita烤瓷贴面粘结抗剪强度的影响

目的　研究氢氟酸蚀刻对 Ｖｉｔａ 烤瓷贴面粘结抗剪强度的影响。方法　选择 ３０ 个氢氟酸（ Ｈ Ｆ）蚀刻瓷贴面的浓度—时间搭配点,模拟临床实际情况,作整体粘结抗剪强度测试和体视显微镜观察。结果　 Ｈ Ｆ酸各浓度—时间点蚀刻烤瓷后的剪切强度值均比对照组高。 Ｈ Ｆ酸浓度—时间的最佳搭配点为：２．５％ ５ｍ ｉｎ,５．０％ ２．５ｍ ｉｎ,７．５％ ,１５％ ５ｍ ｉｎ,１０％ ３０ｓ。烤瓷—树脂—牙釉质间的粘结破坏形式以混合破坏为主。结论　蚀刻可增加烤瓷与牙釉质间的粘结抗剪强度。     

氢氟酸蚀刻机加工陶瓷VitaCerecMarkⅡ表面形貌的扫描电镜研究

采用扫描电镜研究在３０个氢氟酸（ＨＦ酸）浓度－时间点下陶瓷蚀刻表面和断面形貌特征，并测定表面孔隙率和断面蚀刻深度。结果表明：蚀刻深度随浓度和时间递增有增加趋势，但ＨＦ酸浓度在５．０％以上，蚀刻时间７．５ｍｉｎ以上，蚀刻深度变化不明显；孔隙率与ＨＦ酸浓度一时间呈正相关关系。并首次提出机加工瓷蚀刻形貌的四级分类标准     

氢氟酸蚀刻机加工陶瓷Vita Cerec MaikⅡ表面形貌的？…

采用扫描电镜研究在３０个的氢氟酸浓度－时间点下陶瓷刨刻表面和断面形貌特征，并测定表面孔隙率和断面蚀刻深度。结果表明：蚀刻深度随浓度和时间递增有增加趋势，但ＨＦ酸浓度在５．０％以上，蚀刻时间７．５ｍｉｎ以上，蚀刻深度变化不明显；孔隙率与ＨＦ酸浓度一时间呈正相关关系。     

Plat铸造陶瓷表面处理对陶瓷－树脂粘接强度的影响

对陶瓷修复体与预备体间有效的粘接有可能提高陶瓷修复体的抗折裂能力。本研究应用扫描电镜对Ｐｌａｔ铸造陶瓷表面用４％氢氟酸酸蚀１，２，５，７．５，１０，２０ｍｉｎ后的表面形态进行了观察。测试了陶瓷表面喷砂、４％氢氟酸酸蚀２，５，７．５，１０ｍｉｎ及酸蚀５ｍｉｎ＋ＫＨ－５７０处理后与树脂间的抗张粘接强度。结果表明：４％氢氟酸酸蚀２，５ｍｉｎ者可使陶瓷表面粗糙，形成孔隙，可增强其与树脂间的粘接强度，而延长酸蚀时间，陶瓷表面变平整，不利于粘接强度的提高。ＫＨ－５７０处理可进一步提高陶瓷与树脂间的粘接强度。     

Plat铸造陶瓷表面处理对陶瓷—树脂粘接强度…

对陶瓷修复体与预备体间有效的粘接有可能提高陶瓷修复体的抗折裂能力，本研究应用扫描电镜对Ｐｌａｔ铸造陶瓷表面用４％氢氟酸酸蚀１，２，５，７．５，１０，２０ｍｉｎ后的表面形态进行了观察。试验了陶瓷表面喷砂．４％氢氟酸酸蚀２，５，７．５，１０ｍｉｎ及酸蚀５ｍｉｎ＋ＫＨ－５７０处理后与树脂间的抗张粘接强度。结果表明：４％氢氟酸酸蚀２，５ｍｉｎ者可使陶瓷表面粗糙，形成孔隙，可增强其与树脂间的上接强度，而延长     

氯化镧与人牙釉质的反应及生成物分析

以ＰＨ均为４．５的０．０１％－５％氯化镧液及０．１－２％氟化钠液处理人牙釉质块及釉质粉２４Ｈ或４８Ｈ，经原子吸收光谱分析发现Ｌａ＾３＋的存在可加速釉质内Ｃａ＾２＋溶出，且Ｌａ＾３＋浓度越高Ｃａ＾＋溶出也越多，而Ｆ＾－的存在可明显阻抑釉质内Ｃａ＾２＝溶出，但是，溶液浓度及作用时间的不同时对釉质块表面及釉质粉内的反应生成物似无明显影响，经Ｘ线衍射分析发现，０．０１％－５％的氯化镧与人牙釉质作用后均有新     

除气和预氧化对金－瓷结合强度的影响

选用ＣＷ－ＰＡ型烤瓷镍铬合金Ｖｉｔａ－６８瓷粉，采用４组不同的表面处理：①直接上瓷；②除气５ｍｉｎ；③除气１０ｍｉｎ；④除气５ｍｉｎ加预氧化２ｍｉｎ，制成４０根棒盘试件，测其结合强度；制成４片金瓷复合体测其界面形态、界面元素合量及分布情况。结果显示：①非贵金属ＣＷ－ＰＡＮｉ－Ｃｒ合金上瓷前除气可明显提高金－瓷结合强度（Ｐ＜０．０１）约２７％～３０％，但除气时间对金－瓷结合强度的提高无明显作用（Ｐ＞０．０５）。②非贵金属ＣＷ－ＰＡＮｉ－Ｃｒ合金上瓷前预氧化对金－瓷结合强度的提高无统计学意义（Ｐ＞０．０５）。     

氟氢酸酸蚀及偶联剂的应用对烤瓷——树脂粘结强度的影响

目的：评价酸蚀及化学偶联剂对树脂—烤瓷粘结强度的影响。方法：烤瓷试件分７组用５％氟氢酸分别酸蚀０～１８０ｓ，然后一半使用偶联剂，另一半不使用偶联剂，与树脂粘结后测试剪切粘结强度。结果：无偶联剂组酸蚀后可使瓷—树脂粘结强度达到３０ＭＰａ（１５０ｓ），对照组为３ＭＰａ；单独使用偶联剂可使粘结强度达２５．２ＭＰａ，若结合酸蚀剂最高可达３４．３ＭＰａ，但酸蚀后使用偶联剂，酸蚀时间对粘结强度无明显影响；结论：瓷酸蚀是瓷粘结修复中重要的处理方法；偶联剂的使用有利于提高粘结强度，并可用较短的酸蚀时间获得理想的粘结强度。     

激光处理牙釉质,牙本质与复合树脂的粘结研究

对脉冲钕玻璃激光辐射离体牙釉质，牙本质进行表面扫描电镜观察及测定辐射面与光固化复合树脂间粘结强度。结果表明：激光处理牙轴质表面呈云絮状熔融，与复合树脂粘结强度高于对照组，有非常显著性差异（Ｐ〈０．０１），低于酸蚀组，有显著性差异（Ｐ〈０．０５），激光处理牙本质表面呈重叠蜂窝状熔融，与复合树脂粘结强度高于对照组，有非常显著性差异（Ｐ〈０．０１），与酸蚀组无显著性差异（Ｐ〉０．０５），激光处理牙釉质及     

瓷面处理对金属托槽与瓷面粘接性能的影响

目的　研究瓷表面不同处理方法对金属托槽与瓷修复体的粘接强度及去粘接后瓷面完整性的影响。方 法　根据使用粘接剂和表面处理方法的不同,将80个瓷面随机分为8组,每组10个瓷面。分别用京津釉质粘接剂 和光固化复合树脂粘接,表面处理分别行37%磷酸酸蚀、9·6%氢氟酸酸蚀、打磨去釉、瓷面涂硅烷偶联剂4种表面 处理法。试件粘接托槽后经37℃恒温水浴24 h后测定抗剪切强度,记录去粘接后的瓷面破裂情况。对磷酸酸蚀, 氢氟酸酸蚀、打磨去釉的瓷面进行扫描电镜观察。结果　采用氢氟酸酸蚀、打磨去釉、硅烷偶联剂组的粘接抗剪切 强度明显高于磷酸酸蚀组(P<0·01)。打磨去釉后用光固化复合树脂粘接及氢氟酸酸蚀或瓷表面涂硅烷处理后使 用任意一种粘接材料粘接均取得有效的粘接强度。各组去粘接后的瓷破裂率无显著性差异(P>0·05)。结论　氢 氟酸酸蚀、打磨去釉、瓷面涂硅烷偶联剂均可以明显增加金属托槽与瓷面之间的粘接抗剪切强度。瓷面涂硅烷偶 联剂是金属托槽与瓷面粘接时良好的表面处理剂。     

金属托槽与瓷面粘接去除后瓷破损率的比较研究

目的:研究瓷面处理及硅烷偶联剂对金属托槽与瓷面粘接去除后瓷破损率的影响。方法:300个烤瓷试件按不同瓷面处理随机分5组,A组:喷砂3s;B组:金刚砂车针打磨;C组:9.6%氢氟酸酸蚀3min。D组:37%磷酸酸蚀1min;E组:未处理组。再根据是否使用硅烷偶联剂及粘接剂不同分4组,每组15个试件。粘接剂为京津釉质粘接剂及3MUniteTM粘接剂。托槽粘接后检测抗剪切强度,记录瓷破裂指数(PFI)及瓷破损率。结果:使用偶联剂前后PFI有统计学意义(P<0.05),不同处理方式各组间PFI有统计学意义(P<0.05)。结论:瓷面处理及硅烷偶联剂的使用增加了粘接强度,同时增加了瓷面受损的机率。     

To silanate or not to silanate: making a clinical decision

Etched porcelain-bonded restorations have become the treatment of choice for the esthetic restoration of anterior teeth. The bond strength of composite resin to properly etched and silanated porcelain exceeds the cohesive strength of porcelain. Although bonding to enamel is accomplished by only etching the surface to create micromechanical retention, bonding to porcelain is achieved both mechanically through etching porcelain and chemically through the use of a silane coupling agent. Literature supports silanization of porcelain, which provides a more reliable bond than etching with hydrofluoric acid only, although the combination of both are recommended. This article discusses the importance of proper silanization of porcelain in obtaining a durable and reliable resin composite bond with porcelain.     

Metallic bracket to enamel bonding with a photopolymerizable resin-reinforced glass ionomer.

Enamel acid etching plays an important role in treatment on direct bracket bonding. Several studies have been carried out concerning the damage this procedure causes to the enamel. A valuable alternative seems to be the use of photopolymerizable resin-reinforced glass ionomer without acid etching of enamel. This study compares the strength of bracket debonding, the amount of remnant adhesive on the tooth, and the enamel condition in 3 adhesive systems. Three groups were set; in the first group, a glass ionomer with a photopolymerizable resin reinforce and enamel etching with orthophosphoric acid at 37% was used; in the second group, the same ionomer was used but without acid etching; and in the third group, a photopolymerizable resin was used after etching enamel with orthophosphoric acid at 37%. Debonding strength was determined in MPa; a stereoscopic microscope was used to determine the amount of remnant adhesive on the tooth in accordance to ARI and a scanning electron microscope study was made to observe the enamel conditions, existing in debonding among groups (P <.0001), with etching and without etching. The remnant adhesive on the tooth did not show a significant difference (P = 1.000); greater irregularities were found in the enamel in the etching groups. It was demonstrated that the etching was a critical factor in obtaining adequate adhesion strength and that it alters the enamel conditions. Teeth with ionomer and etching had a greater material remnant.     

Effects of buccal versus lingual surfaces, enamel conditioning procedures and storage duration on brackets debonding characteristics

OBJECTIVES: To determine the influence of two enamel conditioning techniques on buccal and lingual tooth surfaces at two different times on debonding strength and tooth damage. METHODS: The study included 50 premolars. Buccal and lingual surfaces of 10 teeth were scanned using SEM before (N=4) and after enamel conditioning by either acid etching or sandblasting prior to acid etching (N=6) for their morphology. The remaining 40 teeth were divided into 2 equal groups, differing in enamel conditioning prior to metallic bracket bonding on the buccal and lingual surfaces. Each group was equally subdivided into short-term (48h) or long-term (12m) water storage. Debonding strength was measured followed by SEM and EDAX for adhesive remnant index (ARI) and calcium remnant index (CRI) left on bracket bases. ANOVA with repeated measures was applied to the results. RESULTS: The buccal enamel was rougher than the lingual one. The surface morphology after the two types of conditioning showed a different pattern. A significantly higher debonding strength was needed to debond the buccal brackets compared to the lingual ones (p<0.05). A significantly higher ARI (p<0.002) and higher CRI (p<0.005) were found in the lingual surface compared with the buccal. No differences were found in debonding strength ARI or CRI regarding the different conditioning or storage duration. CONCLUSIONS: Lingual bonding leads to higher ARI and CRI than buccal bonding. Sandblasting prior to etching does not improve bonding strength for lingual or buccal bonding.     

SEM study of machinable vita cerec mark II porcelain surface morphology after HF acid etching]

After HF acid etching under 5 different HF concentrations and 6 exposing times, the surface morphology of machinable porcelain was examined by scanning electron microscope, and the porsosity percentage and ething depth were determined. The results showed that the etching depth increased with the rising of HF concentration and disposing time until 5%-7.5 min. The porosity percentage of ething surface was positively interrelated with HF concentration and disposing time. It was the first time to classify the etching patterns of machinable porcelain into four groups.     

Bonding to porcelain and gold

To test the effectiveness of bonding orthodontic attachments to porcelain, edgewise brackets were bonded to 160 lower incisor, porcelain denture teeth by means of two different resin systems and three different porcelain bonding agents. Bonding to porcelain was found to be not only effective, but the use of a porcelain primer before bonding resulted in shear strengths comparable to those achieved with conventional acid-etch enamel bonding when the same resin was used. Roughening the porcelain surface and bonding with a heavily filled resin without a porcelain primer provided shear strengths (30.6 Ibs) comparable to conventional acid-etch enamel bonding with a lightly filled resin (28.8 Ibs). Roughening the porcelain surface before bonding, adding porcelain primers, and using highly filled resins all added significantly to bond strength, but caused a progressively greater risk of porcelain fracture during debonding. One of three methods to polish porcelain completely restored a roughened porcelain surface to its former appearance. The porcelain bonding primers failed to provide a significant increase in bond strength when bonding to gold. However, a roughened gold surface bonded with a heavily filled resin provided shear strengths (27.3 Ibs) comparable to conventional acid-etch enamel bonding by means of a lightly filled resin (28.8 Ibs). The use of a highly filled resin on an intact, glazed porcelain surface without using a porcelain primer may provide sufficient bond strength clinically. If more bond strength is needed, the use of Reliance porcelain primer on an intact glaze is preferable to Ormco porcelain primer or Fusion. Still greater bond strength can be developed by roughening the porcelain surface before application of a primer and use of a highly filled resin. The potential for porcelain fracture in debonding, however, is much increased and it is questionable whether bond strengths of this magnitude are required clinically.     

Effects of a self-etching primer and 37% phosphoric Acid etching on enamel: a scanning electron microscopic study

Objective: The purpose of this study was to compare the etching effects of a self-etching primer with 37% phosphoric acid on enamel by using a scanning electron microscope. Bond strength and the site of bond failure were also determined for brackets bonded using SEP and 37% phosphoric acid. Materials and methods: A total of 60 maxillary premolar teeth were used for this study and they were divided into four groups. First two groups were used for studying the different types of etch patterns obtained and the next two groups were used to test the bond strength with the help of Universal testing machine. After debonding, the amount of residual adhesive was assessed according to adhesive remnant index using a stereomicroscope. Results: The majority of etch patterns obtained in the 37% phosphoric acid group were type II, whereas in the SEP group, type IV pattern was more common. There was no statistically significant difference between mean bond strengths obtained with the SEP group and the phosphoric acid group. Use of SEP results in less amount of residual adhesive on tooth surface after debonding. Conclusion: SEP produces more conservative etch pattern compared to 37% phosphoric acid. Use of SEP for bonding provides similar and clinically acceptable bond strength compared to use of 37% phosphoric acid etching technique and requires less clean-up procedures hence, reduces enamel loss. Clinical significance: Use of 37% phosphoric acid for orthodontic bonding yields high bond strength but, causes enamel loss during both etching and debonding. SEPs not only provide adequate bond strength with a more conservative etch pattern but also enable easy debonding, thereby reducing the enamel damage. Keywords: Etch pattern, Enamel, SEM, Self-etching primer. How to cite this article: Nanjannawar LG, Nanjannawar GS. Effects of A Self-Etching Primer and 37% Phosphoric Acid Etching on Enamel: A Scanning Electron Microscopic Study. J Contemp Dent Pract 2012;13(3):280-284. Source of support: Nil Conflict of interest: None declared.     

Bracket bonding with 15- or 60-second etching and adhesive remaining on enamel after debonding

The purposes of this study were to (1) evaluate the shear bond strength of brackets fixed to enamel that has been etched for 15 or 60 seconds, (2) correlate etch time with amount of resin remaining on the enamel after debonding; and (3) evaluate enamel morphology after acid etching. Sixty recently extracted human premolars were randomly divided into two groups. Group 1 was etched for 15 seconds, and group 2 for 60 seconds. A 37% phosphoric acid solution was used for etching. The brackets were Mini-Taurus, and the bonding system was Mono-Lok2. After bonding, the teeth were held at 37 degrees C and 100% humidity for at least 48 hours. To debond, a blade was placed at the ligature groove of the bracket. The force in Newtons required to dislodge the bracket was measured, employing a crosshead speed of 1 mm/min. Bond strength was calculated on the basis of bracket area. Immediately after removal of the bracket, the teeth were rinsed and dried using an air-water syringe, and the adhesive remnant index (ARI) was assessed. Enamel surfaces were analyzed using a scanning electron microscope (SEM). The results showed that shear bond strength was greater (p=0.016) when the enamel was etched for 60 seconds, and the amount of adhesive remaining on the teeth was also greater (p=0.001). There was no significant correlation between shear bond strength and the ARI calculated in the total sample (n=60, r=0.017; p>0.05). SEM evaluation revealed that the shorter etching time created a less retentive enamel surface. Absolute enamel loss also decreased.