激光表面处理对树脂粘接剂与Y-TZP陶瓷冠粘接强度的影响

目的：为评估不同的表面处理方式对树脂粘接剂和Y-TZP粘接强度的影响。方法：制作直径10mm,厚度0.7mm的盘状Y-TZP氧化锆试件60个,并在其表面上饰瓷,Vita VM9饰面瓷的厚度为1.5mm。所有试样分为6组,对照组不进行任何处理;涂层组-烧结前进行化学硅烷涂层（30-μm SiO2）;打磨组-烧结前使用50-μm Al2O3进行空气打磨;激光组-Er：YAG激光组,Nd：YAG激光组,CO2激光组。试样制作完成后将复合树脂粘接到陶瓷上。应用万能试验机测量全瓷修复体与树脂的平均剪切粘接强度（MPa）。使用one-wayANOVA对表面处理方法的影响进行统计学分析,通过Tukey HSD检验进行多重比较（α=0.05）。结果：各组的平均剪切粘接强度（MPa）分别：对照组=14.3±0.8;涂层组=14.9±0.9;打磨组=20.6±1.0;Er：YAG激光组=26.1±1.5;Nd：YAG激光组=27.2±1.3;CO2激光组=26.6±1.2。不同的表面处理方法对复合树脂与全瓷修复体的剪切粘接强度的影响六组间差异有统计学意义（P〈0.01）。激光组、打磨组与对照组间差异有统计学意义,涂层组与对照组间差异无统计学意义。结论：硅烷涂层处理不能提高复合树脂与Y-TZP间的剪切粘接强度。空气打磨和激光照射能提高复合树脂与Y-TZP间的剪切粘接强度。     

Er:YAG激光和Nd:YAG激光辅助的牙漂白对树脂充填体粘接强度和边缘微渗漏的影响

目的：评价Er:YAG激光和Nd:YAG激光辅助的牙漂白对釉质表面树脂充填体粘接强度和边缘微渗漏的影响。方法：将离体牙制备成釉质测试试件（n=64）后随机分为4组（n=16），包括对照组、传统漂白组、Er:YAG激光辅助的漂白组和Nd:YAG激光辅助的漂白组。4组试件分别处理后，检测其釉质表面树脂充填体的剪切粘接强度（n=8）和微渗漏深度（n=8），利用体视显微镜观察各组试件的断裂模式。采用SPSS 26.0软件包对数据进行统计学分析。结果：与对照组相比，传统漂白后釉质表面树脂充填体的粘接强度显著下降，边缘微渗漏显著增加(P<0.05);Er:YAG激光辅助的漂白后釉质表面充填体的剪切粘接强度和微渗漏深度与对照组相比无显著差异（P>0.05）,Nd:YAG激光辅助的漂白后树脂充填体的剪切粘接强度显著下降（P<0.05），但其边缘微渗漏深度与对照组相比无显著差异(P>0.05)。4组试件的粘接断裂模式主要为粘接界面断裂。结论：相比传统漂白方法，激光辅助的牙漂白对树脂充填体粘接强度和微渗漏的影响较小，具有一定的临床优势。     

3种粘接材料与氧化锆陶瓷粘接抗剪切强度的比较

目的研究3种粘接材料与氧化锆陶瓷材料的初期及耐久粘接抗剪切强度。方法将预烧结氧化锆陶瓷片试件喷砂后分为3组,每组20个,分别采用玻璃离子水门汀(GIC组)、Panavia F 2.0树脂粘接剂(PF组)、Clearfil SA Luting树脂粘接剂(SAC组)与核树脂块粘接,每组随机选取10个试件进行冷热循环实验(10 000次,5～55℃),用计算机控制万能材料试验机测定其粘接抗剪切强度。结果未经冷热循环处理的GIC组、PF组、SAC组试件的粘接抗剪切强度值分别为(21.98±1.78)MPa、(30.26±1.73)MPa、(28.63±2.02)MPa,GIC组试件的粘接抗剪切强度低于其他两组(P<0.01),PF组与SAC组的试件相比差异无统计学意义(P>0.05);而冷热循环后,GIC组、PF组、SAC组试件的粘接抗剪切强度值分别为(10.72±2.03)MPa、(28.50±1.54)MPa、(27.02±1.79)MPa,GIC组试件经冷热循环后,其粘接抗剪切强度值明显下降(P<0.05),而其他两组试件经冷热循环后其粘接抗剪切强度值无明显改变(P>0.05)。结论使用玻璃离子可获得较好的初期粘接抗剪切强度,但耐久粘接强度欠佳;含磷酸酯单体的树脂粘接剂可使氧化锆陶瓷获得良好的初期粘接抗剪切强度及耐久粘接抗剪切强度;自粘接型树脂粘接剂操作简便,粘接抗剪切强度与自酸蚀型树脂粘接剂相当,且粘接效果持久。     

负压对钛与树脂粘接剂粘接性能的影响

目的 本研究旨在探讨负压对不同粗糙度钛与树脂粘接剂粘接性能的影响。方法 铸造钛片（1×10×10）mm抛光后随机分为4组（n=50）。1组（对照组）：只作抛光处理;2、3和4组用110μm氧化铝分别在0.2 MPa、0.3 MPa和0.4 MPa的压力下喷砂。扫描电镜观察钛表面形貌并测量粗糙度。随机将每组分为2个亚组：常压（A）组和负压（S）组。A组常规用Panavia F树脂粘接剂粘接钛与树脂柱;S组在钛表面涂布Panavia F粘接剂后,在-0.1 MPa的负压箱内放置20 s,然后粘接树脂柱。每组随机选取一试件纵切,电镜观察粘接界面。将半数试件进行冷热循环（10000次）,对冷热循环前后的粘接试件进行剪切强度测试并分析断裂模式。采用双因素方差分析和Tukey LSD对数据进行统计分析。结果 随着喷砂压力的增加,钛表面粗糙度显著增加（P<0.05）。冷热循环前后,S组的剪切强度均显著高于A组（P<0.05）, S3组的剪切强度最高（P<0.05）。S组混合断裂的比例明显增加（P<0.05）。扫描电镜显示,与A组相比,S组试件与粘接剂结合更紧密。结论 负压能显...     

Nd:YAG激光表面处理对树脂粘接剂与氧化锆粘接强度影响的meta分析

目的:试用Meta分析研究Nd:YAG激光表面处理对树脂粘接剂与氧化锆粘接强度的影响,为提高树脂粘接剂与氧化锆的粘接强度提供循证证据。方法:通过计算机检索PubMed、Cochran Library、EMbase、CNKI、维普、万方等数据库,查找Nd:YAG激光表面处理氧化锆的相关研究,采用RevMan5.2软件对纳入的研究进行Meta分析。结果:共纳入8个研究,合计290个样本。Meta分析结果显示:Nd:YAG激光表面处理组与对照组比较,剪切粘接强度（P=0.02）和粗糙度（P=0.0001）均高于对照组,差异有统计学意义;Nd:YAG激光表面处理组的剪切粘接强度与Al₂O₃喷砂组比较,差异无统计学意义（P=0.87）,Nd:YAG激光表面处理组的粗糙度高于Al₂O₃喷砂组,差异有统计学意义（P=0.02）。结论:Nd:YAG激光表面处理能增加树脂粘接剂与氧化锆的粘接强度,但目前尚不能认为Nd:YAG激光表面处理优于Al₂O₃喷砂处理。     

不同表面处理方法对氧化锆基底材料与饰面瓷结合强度的影响

目的 比较不同表面处理方法对氧化锆基底与饰面瓷之间的结合强度及结合界面微观结构的影响。方法 将WIELAND氧化锆瓷块胚体烧结制成10 mm×5 mm×5 mm大小试件33个。将试件随机分为3组,每组11个。喷砂组在烧结前进行喷砂处理;处理剂组先喷砂处理,再烧结结合衬底瓷;对照组不做处理。3组基底瓷材料采用粉浆涂塑法烧结5 mm×5 mm×5 mm大小的饰面瓷。每组随机抽取1个基底瓷及双层瓷试件,采用扫描电镜、能谱分析方法,研究氧化锆底瓷与饰面瓷之间的结合情况。其余试件则通过电子拉伸机测试结合界面的剪切强度,并用SPSS 17.0软件对实验数据进行统计学分析。结果 喷砂组、处理剂组、对照组试件的剪切强度分别为（18.06±0.59）、（21.04±1.23）、（13.80±1.54） MPa,各组间差异均有统计学意义（P<0.01）。结论 氧化锆胚体烧结前喷砂处理能提高氧化锆基底冠与饰面瓷的结合强度,结合衬底瓷的应用能提高氧化锆基底冠与饰面瓷的结合强度。     

通用型粘接剂和树脂水门汀对氧化锆剪切粘接强度的影响

目的 研究通用型粘接剂和树脂水门汀对氧化锆陶瓷剪切粘接强度和耐久性的影响。方法 氧化锆陶瓷烧结制作20 mm×10 mm×10 mm和10 mm×10 mm×10mm两种尺寸的试件,实验分为12组,将这2种试件分别采用不同的树脂水门汀（RelyX Ultimate树脂水门汀、Clearfil SAC自粘接树脂水门汀）和通用粘接剂（无粘接剂、Scotchbond通用粘接剂、Clearfil SE One粘接剂）在不同的储存条件（水浴、水浴+冷热循环）下进行粘接。测试剪切粘接强度,分析断裂形态。结果 水门汀（F=8.41,P<0.01）和粘接剂（F=30.34,P<0.01）对氧化锆剪切粘接强度的影响有统计学意义;储存条件对剪切粘接强度的影响无统计学意义（F=1.83,P=0.18）。RelyX Ultimate树脂水门汀、无粘接剂、水浴+冷热循环储存时的剪切粘接强度最低（14.02 MPa±6.86 MPa）,RelyX Ultimate树脂水门汀、Scotchbond通用粘接剂、水浴+冷热循环储存时的剪切粘接强度最高（54.12 MPa±8.37 MPa）。结论 通用型粘接剂可提高树脂水门汀对氧化锆的粘接耐久性。非自粘接的树脂水门汀如不使用通用型粘接剂则其粘接耐久性下降。     

通用型粘接剂和树脂水门汀对氧化锆 剪切粘接强度的影响

目的 研究通用型粘接剂和树脂水门汀对氧化锆陶瓷剪切粘接强度和耐久性的影响。方法 氧化锆陶瓷烧结制作20 mm×10 mm×10 mm和10 mm×10 mm×10mm两种尺寸的试件,实验分为12组,将这2种试件分别采用不同的树脂水门汀（RelyX Ultimate树脂水门汀、Clearfil SAC自粘接树脂水门汀）和通用粘接剂（无粘接剂、Scotchbond通用粘接剂、Clearfil SE One粘接剂）在不同的储存条件（水浴、水浴+冷热循环）下进行粘接。测试剪切粘接强度,分析断裂形态。结果 水门汀（F=8.41,P<0.01）和粘接剂（F=30.34,P<0.01）对氧化锆剪切粘接强度的影响有统计学意义;储存条件对剪切粘接强度的影响无统计学意义（F=1.83,P=0.18）。RelyX Ultimate树脂水门汀、无粘接剂、水浴+冷热循环储存时的剪切粘接强度最低（14.02 MPa±6.86 MPa）,RelyX Ultimate树脂水门汀、Scotchbond通用粘接剂、水浴+冷热循环储存时的剪切粘接强度最高（54.12 MPa±8.37 MPa）。结论 通用型粘接剂可提高树脂水门汀对氧化锆的粘接耐久性。非自粘接的树脂水门汀如不使用通用型粘接剂则其粘接耐久性下降。     

不同表面处理对氧化锆陶瓷与牙本质粘接强度的影响

目的 比较喷砂、激光等不同机械处理对氧化锆陶瓷与牙本质粘接强度的影响.方法 制备4 mm×4 mm×6 mm尺寸的长方体瓷块80件,按空白对照及喷砂、Er:YAG激光、Nd:YAG激光、飞秒激光等不同表面处理方式随机分成5组(A～E组,n=16).使用扫描电镜观察表面形貌,轮廓仪测量粗糙度.用树脂粘接剂将瓷块与制备好的...     

氢氟酸质量分数对二硅酸锂玻璃陶瓷表面形貌及树脂粘接的影响

目的 探讨不同质量分数的氢氟酸对二硅酸锂玻璃陶瓷表面形貌及树脂粘接耐久性的影响。方法 制备大小为11 mm×13 mm×2 mm的二硅酸锂玻璃陶瓷片试件72个,经烧结、研磨、清洗后,随机分为3组,每组24个,分别接受质量分数为32%的磷酸、4%的氢氟酸、9.5%的氢氟酸处理20 s,形成酸蚀后试件。每组随机选出4个陶瓷片,1个使用扫描电子显微镜观察陶瓷表面形态,另外3个用表面粗糙度仪测量陶瓷片表面粗糙度参数（Ra、Rz和Rmax）。陶瓷片表面接受硅烷偶联剂/树脂粘接剂/树脂水门汀处理,并与直径3 mm的复合树脂柱粘接形成粘接试件。将每组20个粘接试件分为两组,10个试件直接进行剪切实验,10个试件经20 000次冷热循环后进行剪切实验。结果 氢氟酸处理组试件表面粗糙度参数值均显著高于磷酸处理组;9.5%氢氟酸组除Ra以外的参数值均高于4%氢氟酸组（P<0.05）。冷热循环明显降低了所有实验组的粘接强度（P<0.05）。冷热循环前后,氢氟酸处理组的粘接强度均高于磷酸处理组;尽管4%氢氟酸组的粘接强度高于9.5%氢氟酸组,但9.5%氢氟酸组在冷热循环过程中的粘接强度降低幅度要明显低于4%氢氟酸组（P<0.05）。结论 氢氟酸的质量分数对陶瓷表面形态及与树脂的粘接耐久性有明显影响,9.5%氢氟酸能更有效地保持二硅酸锂玻璃陶瓷的树脂粘接强度。     

Influence of Different Surface Pretreatments of Zirconium Dioxide Reinforced Lithium Disilicate Ceramics on the Shear Bond Strength of Self-Adhesive Resin Cement

AimTo analyze the influence of different surface pretreatments of zirconium dioxide reinforced lithium disilicate ceramics on the shear bond strength of self-adhesive resin cement.Materials and methodsEighty-four zirconium reinforced lithium disilicate disc Vita suprinity (Vita Zahnfabrick, Bad Säckingen, Germany) 14x12x2 mm specimens were fabricated according to the manufacturer''s recommendations. The specimens were embedded in acrylic resin blocks and randomly divided in seven groups (n=12/each) accorrding to the treatment: Group 1- 10% hydrofluoric acid; Group 2- silane; Group 3- hydrofluoric and silane; Group 4- sandblasting with silane; Group 5- Er: YAG laser+ silane; Group 6- Nd: YAG laser + silane; and the control group, in which the specimens were not treated. Round shape composite discs (Filtek Bulk fill, 3M ESPE, St.Paul, Minnesota, USA) with 3.5 mm diameter, were made for shear bond strength testing, and then cemented to the ceramic sample surface using composite cement (RelyX U200 Automix, 3M ESPE, Neuss, Germany). After cementing the composite disc on the sample, the samples were subjected to shear bond strength test of 10 N with a “stress rate” of 1 MPa / s. To determine the nature of the fracture (adhesive, cohesive or adhesive-cohesive), the broken samples were examined under a stereomicroscope. The ANOVA test and the Tukey test were used to compare the values ​​of the bond strength characteristics between different types of materials. All tests were performed with a significance level of α = 0.05.ResultsThere was a significant difference in the shear bond strength of self-adhesive cement to dental lithium-disilicate ceramics reinforced with zirconium dioxide after different preparation protocols (p<0, 05). The treatment of lithium disilicate ceramics reinforced with zirconium dioxide by silanization, sandblasting + silanization, Nd: YAG + silanization resulted in significantly higher bond strength compared to the control group. There was statistically higher bond strength of self-adhesive cement after pretreatment of lithium disilicate ceramics Nd: YAG + silanization compared to Er: YAG + silanization (p <0.05). Adhesive fracture dominated in the control group, sandblasting + silanization group, and in the laser groups, while mixed fracture dominated in other groups.ConclusionUnder the limitations of this study, the Nd:YAG irradiation with silanization could be used as pretreatment for providing greater shear bond strength of self-adhesive resin cement to zirconium reinforced lithium disilicate.     

多次烧结对二硅酸锂陶瓷后牙贴面疲劳性能的影响

目的： 考察经不同烧结次数对后牙二硅酸锂陶瓷牙合贴面疲劳性能的影响。方法： 制作1.2 mm厚的IPS e.max CAD（IC）和IPS e.max Press（IP）后牙牙合贴面,按烧结次数（1次、3次、5次、7次）分组,粘接到上颌磨牙树脂代型上,经热机械疲劳试验后（TMFT）（5-55 ℃ 5000次循环、30-300 N、10 Hz、正弦波、500 000次循环）,进行抗折破坏实验,记录最大断裂载荷值。应用扫描电镜、EDX和 XRD分析材料的显微结构。采用SPSS 20.0软件包对数据进行统计学分析。结果： IC组烧结1次后平均载荷值最高,为（1546.73±192.85） N;IP组烧结3次后平均载荷值最高,为（1504.46±138.56） N。2组材料中,不同烧结次数对牙合贴面断裂载荷值无显著影响（P>0.05）。EDX和 XRD分析显示,2种材料成分无显著差异。SEM观察,在多次烧结后晶体尺寸变短,孔隙率增多。结论： 不同烧结次数对疲劳加载后二硅酸锂陶瓷后牙牙合贴面断裂载荷值有降低趋势,但无统计学差异,可满足临床要求。     

How will surface treatments affect the translucency of porcelain laminate veneers?

PURPOSE

The purpose of this study was to evaluate whether surface treatments affect the translucency of laminate veneers with different shades and thicknesses.

MATERIALS AND METHODS

A total of 224 disc-shaped ceramic veneers were prepared from A1, A3, HT (High Translucent) and HO (High Opaque) shades of IPS e.max Press (Ivoclar Vivadent) with 0.5 mm and 1.0 mm thicknesses. The ceramics were divided into four groups for surface treatments. Group C: no surface treatments; Group HF: etched with hydrofluoric acid; Group SB: sandblasted with 50-µm Al₂O₃; and Group L; irradiated with an Er;YAG laser. A translucent shade of resin cement (Rely X Veneer, 3M ESPE) was chosen for cementation. The color values of the veneers were measured with a colorimeter and translucency parameter (TP) values were calculated. A three-way ANOVA with interactions for TP values was performed and Bonferroni tests were used when appropriate (α=0.05).

RESULTS

There were significant interactions between the surface treatments, ceramic shades and thicknesses (P=.001). For the 0.5-mm-thick specimens there were significant differences after the SB and L treatments. There was no significant difference between the HF and C treatments for any shades or thicknesses (P>.05). For the 1-mm-thick ceramics, there was only a significant difference between the L and C treatments for the HT shade ceramics (P=.01). There were also significant differences between the SB and C treatments except not for the HO shades (P=.768).

CONCLUSION

The SB and L treatments caused laminate veneers to become more opaque; however, HF treatment did not affect the TP values. When the laminate veneers were thinner, both the shade of the ceramic and the SB and laser treatments had a greater effect on the TP values.     

Evaluation of surface roughness and bond strength of quartz fiber posts after various pre-treatments

Purpose. Debonding at the post-adhesive interface is a major problem for quartz fiber posts. The objective of this study was to evaluate surface roughness and bond strength of quartz fiber posts after various surface treatments. Materials and methods. Sixty-six quartz fiber posts were randomly divided into six experimental groups (n = 11) including group C, untreated (control); group SB, sandblasted; group SC, silica coated; group HF, hydrofluoric acid-etched; group N, Nd:YAG laser irradiated; group E, Er:YAG laser irradiated. Surface roughness of the posts was measured before and after pre-treatment. They were then bonded to resin cement and tensile bond strength was determined in a universal testing machine. Furthermore, two-way ANOVA and post hoc comparison tests (α = 0.05) were performed on all data. Results. The highest mean force value was observed in group SB and followed by group E. Tukey’s HSD test showed that there was no statistical difference between group SB and group E (p = 0.673). The highest mean roughness value was observed in group SB and a significant difference was found between group SB and all other groups (p < 0.001). This study reveals that sandblasting and Er:YAG laser irradiation provided a significant increase in bond strength between quartz fiber posts and resin cement. Conclusions. Sandblasting or Er:YAG laser-irradiation of the surface of the quartz fiber post before cementation is recommended for increasing retention.     

Microtensile Bond Strength of a Resin Cement to Silica‐Based and Y‐TZP Ceramics Using Different Surface Treatments

Purpose

To evaluate the effects of different surface treatments on the microtensile bond strength (μTBS) of bonding between resin cement and lithia or zirconia‐based ceramics using an in vitro study.

Materials and Methods

Three zirconia ceramic blocks (IPS e.max ZirCAD) and three lithium disilicate ceramic blocks (IPS e.max CAD) were sintered and duplicated in resin composite. The zirconia specimens underwent various treatments (n = 1): (i) Sandblast + primer (ZiSa); (ii) sandblast + laser irradiation + primer (ZiSaLa); or (iii) laser irradiation + primer (ZiLa). The lithium disilicate specimens also underwent various treatments: (i) sandblast + HF + silane (LiSaE); (ii) sandblast + silane (LiSa); or (iii) sandblast + laser irradiation + silane (LiSaLa). The ceramic–composite blocks were cemented with resin cement and cut to produce bars with approx. 1 mm² bonding areas. The specimens were thermocycled, and bond strength tests were performed in a universal testing machine. The fracture type was determined by observing the fractured surface under a stereomicroscope. The mean bond strengths of the specimens were statistically analyzed using one‐way ANOVA and Duncan's tests (α = 0.05).

Results

Mean comparison of the μTBS showed no significant difference between LiSaE and LiSa (p > 0.05), but significant differences between LiSaE and other groups (p ≤ 0.01). No significant differences were found between the ZiSaLa and ZiSa groups (p > 0.05). The modes of failure in all groups were mostly adhesive (57% to 80%). The mean bond strengths in laser‐irradiated ceramics were significantly lower than those from other surface treatments. All ZiLa specimens debonded before testing (pretest failure).

Conclusions

Lithium disilicate ceramic surface treated with a combination of sandblasting and silane application provided a bond strength comparable to that provided by sandblasting in combination with acid etching and applying silane. Groups treated with laser irradiation had significantly lower bond strengths than other groups.     

Adhesion between glass fiber posts and resin cement: evaluation of bond strength after various pre-treatments

Purpose. To evaluate surface roughness and bond strength of glass fiber posts to a resin cement after various surface treatments. Materials and methods. Sixty individually formed glass fiber posts with a diameter of 1.5 mm and a length of 20 mm were used for this study. They were randomly assigned to six groups of pre-treatment (n = 10/group): Group C, untreated (control); Group SB, sandblasted; Group SC, silica coated; Group HF, hydrofluoric acid-etched; Group N, Nd:YAG laser irradiated; Group E, Er:YAG laser irradiated. Surface roughness of the posts was measured before and after pre-treatment. The posts were then bonded to resin cement and tensile bond strengths were determined in a universal testing machine. For statistical analysis, two-way ANOVA and post-hoc comparison tests (α = 0.05) were performed. Results. The highest bond strength value was observed in group HF, followed by group SC. There was a statistically significant difference in bond strength between group C and groups HF, SC and E (p < 0.001, p = 0.002 and p = 0.041, respectively). Posts of group SB and group N showed the highest surface roughness. Conclusions. The findings of the present study reveal that hydrofluoric acid-etching, silica coating and Er:YAG laser irradiation provided a significant increase in bond strength between glass fiber posts and resin cement.     

The influence of internal surface treatments on tensile bond strength for two ceramic systems

STATEMENT OF THE PROBLEM: The ceramic composition and surface microstructure of all-ceramic restorations are important components of an effective bonding substrate. Hydrofluoric acid and sandblasting are well-known procedures for surface treatment; however, surface treatment for high alumina-containing and lithium disilicate ceramics have not been fully investigated. PURPOSE: This in vitro study evaluated the tensile bond strength of resin cement to two types of ceramic systems with different surface treatments. METHODS AND MATERIALS: Thirty specimens of each ceramic system were made according to the manufacturer's instructions and embedded in polyester resin. Specimens of In-Ceram Alumina [I] and IPS Empress 2 [E] were distributed to three groups with differing surface treatments (n = 10): sandblasting with 50 microm aluminum oxide (APA); sandblasting with 110 microm aluminum oxide modified with silica particles (ROCATEC System-RS); a combination of sandblasting with APA and 10% hydrofluoric acid etching (HA) for two minutes on In-Ceram and for 20 seconds for IPS Empress 2. After the respective surface treatments, all the specimens were silanated, and Rely-X resin cement was injected onto the ceramic surface and light polymerized. The specimens were stored in distilled water at 37 degrees C for 24 hours and thermally cycled 1,100 times (5 degrees C/55 degrees C). The tensile bond strength test was performed in a universal testing machine at a 0.5 mm/minute crosshead speed. RESULTS: The mean bond strength values (MPa) for IPS Empress 2 were 12.01 +/- 5.93 (EAPA), 10.34 +/- 1.77 (ERS) and 14.49 +/- 3.04 (EHA). The mean bond strength values for In-Ceram Alumina were 9.87 +/- 2.40 (IAPA) and 20.40 +/- 6.27 (IRS). All In-Ceram specimens treated with 10% hydrofluoric acid failed during thermal cycling. CONCLUSION: The Rocatec system was the most effective surface treatment for In-Ceram Alumina ceramics; whereas, the combination of aluminum oxide sandblasting and hydrofluoric acid etching for 20 seconds worked more effectively for Empress 2 ceramics.     

Er:YAG激光不同能量预处理对自粘结树脂水门汀剪切粘结强度的影响

目的探讨Er:YAG激光不同能量预处理对自粘结树脂水门汀剪切粘结强度的影响。方法按照纳入标准收集人离体磨牙70颗,根据对牙本质表面Er:YAG激光预处理能量的不同随机分为7组:A组(空白对照)、B组(50 m J,10 Hz)、C组(100 m J,10 Hz)、D组(150 m J,10 Hz)、E组(200 m J,10 Hz)、F组(250 m J,10 Hz)、G组(300 m J,10 Hz)。每组10颗牙中随机取2颗切取3 mm厚的牙本质片,按相应分组用不同激光能量预处理后扫描电镜观察;每组剩余8颗牙包埋后,制备一致标准牙本质表面,按相应分组要求预处理后,用自粘结树脂水门汀Rely XTMUnicem将其与Everest ZS氧化锆瓷片粘结,24 h后测试各组剪切粘结强度并进行统计学分析。结果扫描电镜观察显示Er:YAG激光预处理后牙本质表面形态改变明显,变得粗糙不平,牙本质小管开放,无玷污层,管周和管间牙本质脱矿,一定能量范围内呈现较好的粘结表面;剪切粘结强度结果显示Er:YAG激光预处理可增强自粘结树脂水门汀Rely XTMUnicem的剪切粘结强度(P<0.01);C、D、E组的剪切粘结强度与A组有显著性差异(P<0.05)。结论粘结强度与牙本质的粘结表面密切相关,合适能量下的Er:YAG激光预处理能获得较好的牙本质粘结表面,提高自粘结树脂与牙本质和氧化锆瓷的剪切粘结强度。     

Peel strength of denture liner to PMMA and polyamide: laser versus air-abrasion

PURPOSE

This study investigated the effect of laser parameters and air-abrasion on the peel strength of silicon-based soft denture liner to different denture resins.

MATERIALS AND METHODS

Specimens (N=180) were prepared out of three different denture base resins (Rodex, cross-linked denture base acrylic resin; Paladent, heat-cured acrylic resin; Deflex, Polyamide resin) (75 mm × 25 mm × 3 mm). A silicon-based soft denture liner (Molloplast B) was applied to the denture resins after the following conditioning methods: a) Air-abrasion (50 µm), b) Er,Cr:YSGG laser (Waterlase MD Turbo, Biolase Technology) at 2 W-20 Hz, c) Er,Cr:YSGG laser at 2 W-30 Hz, d) Er,Cr:YSGG laser at 3 W-20 Hz, e) Er,Cr:YSGG laser at 3 W-30 Hz. Non-conditioned group acted as the control group. Peel test was performed in a universal testing machine. Failure modes were evaluated visually. Data were analyzed using two-way ANOVA and Tukey''s test (α=.05).

RESULTS

Denture liner tested showed increased peel strength after laser treatment with different parameters (3.9±0.4 - 5.58±0.6 MPa) compared to the control (3.64±0.5 - 4.58±0.5 MPa) and air-abraded groups (3.1±0.6 - 4.46±0.3 MPa), but the results were not statistically significant except for Paladent, with the pretreatment of Er,Cr:YSGG laser at 3 W-20 Hz. Polyamide resin after air-abrasion showed significantly lower peel strength than those of other groups (3.1±0.6 MPa).

CONCLUSION

Heat-cured acrylic resin, PMMA, may benefit from Er,Cr:YSGG laser treatment at 3 W-20 Hz irradiation. Air-abrasion of polyamide resins should be avoided not to impair their peel bond strengths to silicon-based soft denture liners.     

Ex vivo study of the adhesion of an epoxy-based sealer to human dentine submitted to irradiation with Er : YAG and Nd : YAG lasers

AIM: To evaluate the adhesion of an epoxy-based sealer to human dentine submitted to irradiation with Er : YAG or Nd : YAG laser at various parameters. METHODOLOGY: Ninety maxillary canine teeth were sectioned transversely at the cemento-enamel junction and at the root tip to leave an 8-mm-long cylinder. The tooth specimen was centred in a metallic ring (16 mm diameter and 8 mm height) and embedded in acrylic resin. The root canals were prepared using a low-speed handpiece and a conical diamond bur, which was attached to a paralleling device. This bur was lowered to a depth previously determined by a silicone stop. Specimens were divided into nine groups: group I, dentine was treated with 2 mL of 17% EDTAC for 5 min. Groups II-V were irradiated with Er : YAG laser at the following parameters: group II - 8 Hz and 200 mJ input (120 mJ output); group III - 8 Hz and 400 mJ input (240 mJ output); group IV - 16 Hz and 200 mJ input (120 mJ output); group V - 16 Hz and 400 mJ input (240 mJ output). Groups VI-IX were irradiated with Nd : YAG laser at the following parameters: group VI - 10 Hz and 1 W input (0.4 W output); group VII - 10 Hz and 2 W input (0.8 W output); group VIII - 15 Hz and 1 W input (0.4 W output); group IX - 15 Hz and 2 W input (0.8 W output). The root canals were filled with an epoxy-based root canal sealer and submitted to a push-out test. RESULTS: Statistical analysis showed significant differences (P < 0.01) between Er : YAG and Nd : YAG laser treatments at the higher frequencies compared with 17% EDTAC. Greater adhesion values were obtained for groups IV and V (Er : YAG laser) and groups VIII and IX (Nd : YAG laser), which were statistically different from groups II and III (Er : YAG laser) and groups VI and VII (Nd : YAG laser). Treatment with only 17% EDTAC had the lowest adhesion values. CONCLUSIONS: An increase in frequency, independent of power settings, of the lasers used in this study increased adhesion of an epoxy-based root canal sealer.