复合树脂重塑喇叭状残根的微渗漏研究

目的比较全酸蚀和自酸蚀两种黏结系统联合复合树脂重塑喇叭状残根的微渗漏。方法选择正畸拔除下颌第一前磨牙16颗,制备形成喇叭状残根,随机分为2组,分别采用Prime&bond NT黏结剂和自酸蚀黏结剂XenoⅢ联合DURAFILL复合树脂重塑根管壁,采用纤维桩加树脂核修复。经过500次冷热循环后,置于印度墨水1周。经透明化处理,在体视显微镜下观察重塑材料与根管壁之间的微渗漏情况。结果自酸蚀组微渗漏小于全酸蚀组,且有统计学差异(P<0.05)。结论自酸蚀黏结系统联合复合树脂重塑喇叭状残根的封闭能力优于全酸蚀黏结系统。     

表面封闭法提高正畸酸蚀牙面抗磨耗性能的实验研究

目的:研究正畸酸蚀处理对牙面抗磨耗能力的影响,并探讨用表面封闭法提高正畸酸蚀牙面抗磨耗性能的可行性。方法:因正畸需要拔除的9个前磨牙分为3组,即空白对照组、自酸蚀处理液TRANS-BONDTMPLUS酸蚀组、FILTEK FLOW1400A3流动复合树脂封闭组,经冷热循环后在牙刷磨耗实验机上磨耗31000次,然后扫描电镜(scanning electron microscope,SEM)观察不同处理的牙齿表面磨耗的差异性。结果:酸蚀后的牙齿表面磨耗程度明显高于未酸蚀的牙齿;流动复合树脂封闭层仍保留在牙齿表面。结论:正畸酸蚀处理可降低牙齿抗磨耗能力;流动复合树脂表面封闭法能对抗正畸酸蚀处理对牙面的这种影响,提高其抗磨耗能力。     

Er：YAG激光制备窝洞对树脂充填微渗漏的影响

目的应用离体牙比较复合树脂与Er：YAG激光及传统牙钻制备窝洞洞壁间微渗漏的差异。方法将30颗前磨牙随机分为3组,每组10颗牙,制备Ⅴ类洞：Ⅰ组牙钻预备加酸蚀处理;Ⅱ组单纯激光预备组、Ⅲ组激光预备加酸蚀处理组,经冷热循环染色后,在体视显微镜下记录微渗漏程度并应用非参数统计方法分析数据。结果各组内颈壁的染料渗透情况均比壁明显（P〈0.05）;在壁,单纯激光预备组产生的微渗漏最严重（P〈0.05）,激光预备加酸蚀处理组与牙钻预备加酸蚀处理组微渗漏无统计学差异;在颈壁,三组充填体边缘微渗漏情况无统计学差异。结论Er：YAG激光可代替牙钻备洞,结合酸蚀处理与充填体有良好的密合度。     

复合树脂与Er,Cr∶YSGG激光制备的窝洞壁间微渗漏评价

目的:研究复合树脂与Er,Cr∶YSGG(掺铒铬钇钪镓石榴石)激光制备的窝洞壁间微渗漏.方法:将30颗离体前磨牙随机分为3组(n=10),制备Ⅴ类洞.第1组为激光预备加37％磷酸处理组,第2组为激光预备加FL-BOND处理组,第3组为激光预备加17％EDTA处理组.经冷热循环染色后,采用染料渗入法和扫描电镜方法观察充填体微渗漏情况,采用SPSS11.0软件包对数据进行统计学处理.结果:骀壁处染料渗入结果显示,第2组的染料渗入评分最小,与其余2组有显著差异(P＜0.05),第1组与第3组无显著差异.扫描电镜观察显示,第2组与第3组的边缘微缝隙宽度有显著差异(P＜0.05),其余各组间无显著差异,此结果与染料渗入法的结果不完全一致.龈壁处,3组染料渗入评分及充填体边缘微缝隙宽度均无显著差异,仅第2组(牙合)壁与龈壁的染料渗入评分及边缘微缝隙宽度有显著差异(P＜0.05).结论:自酸蚀黏结剂可有效减少复合树脂与Er,Cr∶YSGG激光制备的Ⅴ类洞(牙合)壁间微渗漏;在全酸蚀黏结剂及应用EDTA处理剂的条件下,复合树脂与Er,Cr∶YSGG激光制备的窝洞壁间微渗漏无差异.     

不同黏结剂和黏结方法对托槽周围微渗漏的影响

目的：观察、比较不同黏结材料、不同酸蚀方法黏结正畸金属托槽后的微渗漏情况。方法：选择因正畸拔除的健康前磨牙36颗,随机分成3组,每组12颗。A组：37％磷酸酸蚀,京津釉质黏结剂黏结金属托槽;B组：37％磷酸酸蚀．3M Transbond光固化黏结剂黏结;C组：自酸蚀系统＋3M Transbond光固化黏结剂。所有样本进行冷热循环,1％亚甲蓝溶液染色后．立体显微镜下观察并测量各组托槽周围微渗漏情况。用SPSS 11．0统计软件对试验结果先进行方差齐性检验,F检验有统计学意义,进一步用Q检验进行组间比较。结果：①3组间微渗漏差别有统计学意义（F=22．462．P〈0．01）,两两比较发现,A组与B组的微渗漏差别无统计学意义（P〉0．05）;而A、B组均较C组的微渗漏小,差别有显著性（P〈0．05）。②3组龈方微渗漏均大于[牙合]方,差别有统计学意义（分别为P〈0．05、P〈0．01、P〈0．01）。结论：①微渗漏的大小与黏结剂的种类无明显关系。②不同酸蚀方法间的微渗漏差别明显,自酸蚀组较磷酸酸蚀组的微渗漏明显大。③同种材料、同种酸蚀方法,托槽龈方微渗漏明显大于[牙合]方。     

Er：YAG激光预备及酸蚀处理对复合树脂充填体微渗漏的影响

目的 研究Er∶YAG激光备洞及酸蚀处理对复合树脂充填体微渗漏的影响.方法 将40颗离体前磨牙随机平均分为5组制备洞型：A组,高速牙钻预备加酸蚀;B组,Er∶YAG激光预备;C组,Er∶YAG激光预备加酸蚀;D组,高速牙钻预备加Er∶YAG激光蚀刻;E组,高速牙钻预备加Er∶YAG激光蚀刻后酸蚀.所有样本经复合树脂充填后交替放置于5℃与55℃水中各1 min,间隔45 s,共2000个周期进行冷热循环,然后用0.2％亚甲基蓝染色后颊舌向劈开,体视显微镜下观察剖面,记录其微渗漏情况,并进行统计学分析.另选6颗离体前磨牙,随机分为3组,按上述A、B、C三组方法制备,扫描电镜下观察其牙本质界面的结构.结果 在（牙合）壁与龈壁,B组染料渗入严重,到达洞底,微渗漏最大,与其他各组相比有统计学差异（P＜0.05）,A、C、D、E组染料渗入表浅,微渗漏程度之间没有统计学差异（P＞0.05）.扫描电镜下,A组牙本质表面较平整,无玷污层存在,牙本质小管口开放.B组牙本质表面不平整如鳞片状,无玷污层,牙本质小管口开放,直径小于酸蚀组.C组牙本质小管口开放,无玷污层存在,管周牙本质脱矿明显.结论 单纯Er∶YAG激光预备比传统牙钻制备结合酸蚀处理洞型更易发生微渗漏,若Er∶YAG激光预备结合酸蚀剂处理可以使微渗漏程度减小,Er∶YAG激光蚀刻可以达到和酸蚀剂类似的效果.     

喷磨处理氟斑牙牙釉质与复合树脂黏结界面微渗漏的研究

目的体外评价空气喷磨、酸蚀和两者结合处理氟斑牙牙釉质对其与复合树脂黏结界面间微渗漏的影响。方法选择18颗氟斑牙正畸患者拔除的第一前磨牙为研究对象,随机分为A、B、C三组,对其牙釉质分别进行单纯酸蚀、单纯喷磨、喷磨加酸蚀处理而后黏结树脂,进行冷热循环、染色。立体显微镜下观察并测量黏结界面微渗漏情况。方差检验进行统计学分析。结果单纯空气喷磨组的微渗漏测量值为(1.51±0.28)mm,与常规酸蚀组(1.03±0.33)mm相比,二者之间有统计学差异(P<0.05);喷磨加酸蚀组的微渗漏测量值为(0.51±0.28)mm,与常规酸蚀组相比亦有统计学差异(P<0.01)。结论采用空气喷磨加酸蚀预处理氟斑牙牙釉质可减少氟斑牙牙釉质与复合树脂间的微渗漏。     

3种复合树脂充填Ⅴ类洞的微渗漏比较研究

目的:比较义获嘉N Ceram纳米瓷化树脂、N Flow流动树脂及Bulk Fill 三次方大块充填树脂充填上颌前磨牙Ⅴ类洞后树脂充填体边缘的微渗漏情况,评估3种不同复合树脂的抗微渗漏性能,寻找较好的充填V类洞的复合树脂材料.方法:选取牙体完整、健康的人离体前磨牙66颗,随机分为3组(n=22).所有样本牙在颊侧颈部制备标准V类箱状洞型(长4 mm、宽3 mm、深2 mm).3组试验牙经选择性釉质酸蚀自黏结后,分别使用N Ceram纳米瓷化树脂(A组)、N Flow流动树脂(B组)及Bulk Fill三次方大块充填树脂(C组)进行充填.充填完成后,3组试验牙均行弱光启动固化,打磨抛光.将3组样本进行1500个周期的冷热循环,2％亚甲基蓝浸泡染色7d,然后沿牙体颊舌向切片.每组随机选取2颗样本牙,在扫描电镜下观察牙体-充填体交界面的密合程度;其余60颗样本牙在体视显微镜下(×40)观察剖面充填体的微渗漏情况.采用Spot Advanced软件测量微渗漏深度,并根据0～3分分别给(牙合)、龈壁微渗漏程度评分.采用SPSS17.0软件包对各组的微渗漏深度分别进行Kruskal-Wallis秩和检验和Mann-Whitney检验.结果:义获嘉Bulk Fill组树脂在3组中龈壁的微渗漏最小,且与另外2组相比有显著差异,N Ceran纳米树脂组与N Flow流动树脂组龈壁的微渗漏均较高(P＜0.05);3组复合树脂材料(牙合)壁的微渗漏无显著差异(P＞0.05);3组树脂(牙合)壁的微渗漏值均比龈壁小且差异显著(P＜0.05).结论:3组树脂在(牙合)壁的微渗漏值无显著差异.义获嘉Bulk Fill组树脂充填V类洞时.在3组中龈壁的微渗漏最小,且与另外2种树脂之间有显著差异.     

Er:YAG激光照射对窝沟封闭剂微渗漏影响的研究

目的通过体外观察Er:YAG激光照射对窝沟封闭剂微渗漏的影响,探讨其做为窝沟封闭前釉质预处理方式的可能性。方法以20颗离体磨牙做为标本,随机分成4组,每组5颗,窝沟分别采用下列方式处理,A组:杯状刷清洗后酸蚀,B组:钻处理后酸蚀,C组:Er:YAG激光照射,D组:Er:YAG激光照射后酸蚀,然后窝沟封闭,冷热循环,染料渗透,切片,体视显微镜观察各组窝沟封闭剂与釉质面的微渗漏情况。结果单纯Er:YAG激光照射组微渗漏最严重(P<0.05),3种方式预备窝沟经酸蚀后窝沟封闭剂边缘微渗漏无显著性差异(P>0.05)。结论Er:YAG激光照射后的窝沟放置窝沟封闭剂前还应酸蚀。     

自酸蚀粘接剂对窝沟封闭微渗漏影响的实验研究

目的:研究自酸蚀粘接剂对窝沟封闭微渗漏的影响。方法:将60颗离体的无龋上颌前磨牙随机分为3组,每组20颗,以磷酸酸蚀组为对照组,AdperTMEasy One组和iBond组为实验组,分别进行窝沟封闭;每组15颗牙进行微渗漏实验,5颗牙用于电镜观察结合界面。结果:AdperTMEasy One组与对照组微渗漏差异无统计学意义(P0.05),但有小于后者的趋势;iBond组微渗漏明显大于对照组(P0.01)。电镜观察显示AdperTMEasy One组封闭剂与釉质界面清晰连续,两者结合紧密。结论:自酸蚀粘接剂AdperTMEasy One用于窝沟封闭效果优于iBond。     

Effect of Resin Coating and Chlorhexidine on the Microleakage of Two Resin Cements after Storage

Purpose: This study evaluated the effect of resin coating and chlorhexidine (CH) on microleakage of two resin cements (Panavia F2.0, Nexus 2) after water storage. Materials and Methods: Class V cavities were prepared on the facial and lingual surfaces of 120 intact human molars with gingival margins placed 1 mm below the cementoenamel junction. Indirect composite inlays were fabricated. The specimens were randomly assigned into six groups (n = 40). Indirect composite inlays (Gradia) were cemented as follows: Group 1 (control): inlays were cemented with Panavia F2.0 according to the manufacturer's instructions. Group 2: the ED‐primed (ED Primer, Kuraray Dental, Tokyo, Japan) dentin was coated with a resin layer before cementation of the inlays with Panavia F2.0. Group 3: a 2% CH solution was applied before bonding with Panavia F2.0. Group 4: after CH application, the primed dentin was coated with a resin layer before cementation with Panavia F2.0. Group 5: (control) after applying Optibond Solo Plus, the inlays were cemented with Nexus 2. Group 6: after etching, CH was applied, and cementation was performed similarly to group 5. Half the specimens in each group were stored in distilled water for 24 hours, while the other half were stored in distilled water for 6 months. After storage, the teeth were placed in 1% methylene blue dye for 24 hours, sectioned, and evaluated under a 20× stereomicroscope. Dye penetration was scored using 0 to 3 criteria. Data were analyzed using nonparametric tests. Results : Resin coating of ED primer for Panavia F2.0 significantly reduced microleakage at the gingival margins after 6 months (p < 0.05). CH application in Panavia F2.0 did not lead to a significant difference in the microleakage at both margins, after 24 hours and 6 months (p > 0.05). The application of CH showed significantly less microleakage than that of the control group at the gingival margins of Nexus 2 after 6 months. In general, gingival margins showed more microleakage than occlusal margins. Conclusion: An additional resin layer applied to a self‐etch cement can improve long‐term dentinal sealing for indirect restorations, while CH cannot; however, CH reduces gingival microleakage in an etch‐and‐rinse cement after aging.     

Dentine bond strength and microleakage of flowable composite,compomer and glass ionomer cement

Background: To assess in vitro the dentine bond strength and microleakage of three Class V restorations viz. flowable composite, compomer and glass ionomer cement. Methods: Eighteen dentine specimens were prepared and randomly distributed among three groups. Three kinds of restoration materials were each bonded on prepared dentine surfaces in three groups as per the manufacturers’ instructions. Group Aelite: Tyrian SPE (a no‐rinse, self‐priming etchant) + One Step Plus (an universal dental adhesive) + Aeliteflo (a flowable composite); Group Dyract: Prime & Bond NT (a no‐rinse, self‐priming dental adhesive) + Dyract AP (a compomer); Group GlasIonomer: GlasIonomer Type II (a self‐cured restorative glass ionomer). Fifteen dentine/restoration microtensile bond test specimens were prepared from each group and were subjected to microtensile bond strength testing. The bond interfaces were observed morphologically using a scanning electron microscope (SEM). Twenty‐four cervical cavities of 4.0 mm mesiodistal length, 2.0 mm occlusogingival height and 1.5 mm depth were prepared at the cemento‐enamel junction (CEJ) on both buccal and lingual surfaces of each tooth. The cavities were each filled with flowable composite (Group Aelite), compomer (Group Dyract) and glass ionomer cement (Group GlasIonomer) using the same material and methods as for the microtensile bond tests. Microleakage of each restoration was evaluated by the ratio of the length of methylene blue penetration along the tooth‐restoration interface and the total length of the dentine cavity wall on the cut surface. Results: One‐way ANOVA and least significant difference (LSD) tests revealed statistically significant differences among the dentine bond strength for Group Aelite (28.4 MPa), Group Dyract (15.1 MPa) and Group GlasIonomer (2.5 MPa). SEM images showed intimate adaptation in the restoration/dentine interfaces of Group Aelite and Group Dyract. All of the systems tested in this study presented microleakage. However, both Group Aelite (0.808) and Group Dyract (0.863) had significantly less microleakage than Group GlasIonomer (0.964). There were no statistically significant microleakage differences between Group Aelite and Group Dyract, and no statistically significant microleakage differences between the occlusal margin and gingival margin. Conclusions: None of the systems tested in this study completely eliminated microleakage. However, both the flowable composite and compomer provided stronger dentine bond strengths and better margin sealing than the conventional glass ionomer cement. Occlusal forces exerted the same effects on microleakage of the occlusal margin and gingival margin in cervical cavities.     

The effect of LED curing mode on microleakage of Class V cavity restored by silorane-based composite

Abstract

Objective. This in vitro study evaluated the effect of soft-start curing mode by LED unit on the marginal microleakage of silorane composite restoration. Materials and methods. Class V cavities were prepared on the buccal surfaces of 80 extracted molars at the cementoenamel junction and randomly divided into eight groups. In groups 1–4, four adhesive/composite combinations (silorane/silorane, silorane/Z250, Adper Single Bond/Z250, Clearfil SE Bond/Clearfil AP-X) were applied and the composites were cured under standard mode at 1500 mW/cm² for 20 s. In the other four groups, after applying the same adhesive/composite combinations, the composites were cured at 550 mW/cm² for 10 s followed at 1500 mW/cm² for 15 s. After 24 h of water storage and thermocycling, the specimens were placed in 1% methylene blue solution. The dye penetration was assessed under a stereomicroscope. The data were analysed using non-parametric tests. Results. There were no significant differences among four groups for two curing modes at the occlusal and gingival margins (p > 0.05). The soft-start curing had a positive effect on the gingival marginal sealing of group 1 (p < 0.05), but not for the other three groups (p > 0.05). Conclusion. The beneficial effect of relatively high soft-start curing on marginal sealing of Class V restoration depends on a combination of the adhesive and composite types, having a positive effect on silorane adhesive/silorane-based composite at the gingival margin.     

Effect of different monomer-based composites and acid etching pre-treatment of enamel on the microleakage using self-etch adhesives systems

Objective. To evaluate quantitatively the marginal microleakage of restorations carried out with self-etching adhesives with or without prior phosphoric enamel acid etching of silorane or methacrylate resin-based composite restorations subjected to thermal cycling. Materials and methods. Forty cavities were prepared at the proximal surface of bovine incisors and randomly divided according to the etching of the enamel and restorative system used. The groups were restored with methacrylate [Adper SE Plus adhesive (3M ESPE) + Filtek Z250 (3M ESPE)] or silorane [Filtek LS adhesive (3M ESPE) + Filtek LS composite (3M ESPE)] restorative systems, light-cured using a LED unit (Bluephase 16i, Vivadent). After restorative procedure and thermocycling (1000 cycles), the specimens were immersed in methylene blue for 2 h. The specimens were triturated and the powder was used for analysis in an absorbance spectrophotometer. Data were statistically analyzed by 2-way ANOVA (alpha = 0.05). Results. No statistical difference between the restorative materials tested with or without previous acid etching of enamel in Class II marginal microleakage was observed (p > 0.05). Conclusions. The use of acid etching prior to self-etching adhesives did not interfere on the microleakage of methacrylate- or silorane-based restorations.     

Marginal adaptation and microleakage of a bulk-fill composite resin photopolymerized with different techniques

The purpose of this study was to investigate the marginal adaptation and microleakage of SonicFill composite with different photopolymerization techniques. Class II cavities were prepared in 40 premolars and divided into groups according to the photopolymerization technique (n = 10): G1:1200 mW/cm² for 20 s; G2:1200 mW/cm² for 40 s; G3:Soft-start with 650 mW/cm² for 5 s and 1200 mW/cm² for 15 s; G4:Soft-start with 650 mW/cm² for 10 s and 1200 mW/cm² for 30 s. The cavities were restored with OptiBond FL adhesive and SonicFill. Epoxy resin replicas were obtained before and after thermocycling. The occlusal and cervical margins were analyzed with scanning electron microcopy and expressed as the percentage of continuous margins (%CM). The specimens were submitted to microleakage with silver nitrate. ANOVA and Tukey’s test revealed that the %CM at the linguo-occlusal margin for group 1 (83.19%) was significantly different from groups 2, 3 and 4, which had values over 95%. At the cervical margin, there was no statistically significant difference between the groups. After thermocycling, there was a significant decrease in %CM. The predominant score of microleakage was 1 in enamel and 3 in dentin. The SonicFill composite led to gap formation and microleakage, especially in the dentin at the cervical margin, regardless of the photopolymerization technique employed.     

Microleakage of composite restorations after acid or Er-YAG laser cavity treatments.

OBJECTIVES: The purpose of this study was to compare microleakage of Class V restorations following acid, laser or laser and acid treatment of cavity walls. METHODS: Standardized lingual and buccal Class V preparations were made in 18 human extracted third molars. The preparations were randomly assigned to three equal groups (n=12). Group 1: cavities were treated with 35% phosphoric acid. Group 2: cavities were irradiated with an Er-YAG laser at 2Hz and 250mJ on dentin and 300mJ on enamel, with water cooling. Group 3: cavities were irradiated with the laser before acid etching. Scotchbond 1 Adhesive System and Z100 resin composite were used for restorations. The specimens were stored in water for 24h at 37 degrees C and thermally cycled (500x) between 6-60 degrees C. After 24h immersion in 0.5% basic fuchsin, dye penetration was recorded according to an ordinal scale. Data were analysed using non-parametric statistical tests (Kruskal-Wallis and Mann-Whitney). RESULTS: On the occlusal walls, microleakage in acid etched cavities was significantly lower than that achieved after laser treatment (P<0.001) or after both treatments (P<0.05). On the gingival walls, no statistical differences were found. SIGNIFICANCE: Laser irradiation of enamel is not a valid alternative to acid-etching pretreatment for resin composite materials adhesion. Acid etching alone gave the lowest microleakage at the occlusal margin. No differences were found for microleakage on gingival wall, although lased dentin surfaces presented several characteristics that appear to be advantageous for bonding.     

Effect of Aging on Coronal Microleakage in Access Cavities through Metal Ceramic Crowns Restored with Resin Composites

Purpose: The purpose of this in vitro study was to determine if packable resin composite with/without flowable resin composite has the ability to prevent coronal leakage in restored endodontic access openings following aging. Materials and Methods: Eighty simulated standardized access cavities of metal‐ceramic crowns were fabricated and fixed on Vitrebond cavities filled with an epoxy resin. The specimens were randomly divided into two main groups: (1) Group A—Access cavities filled with only packable composite (Filtek P60); (2) Group B—Access cavities filled with Filtek P60 and a flowable composite (Filtek Z350) as liner. Each main group was further subdivided randomly into four subgroups according to water storage and thermocycling periods. All specimens were immersed in blue ink solution for 24 hours and then sectioned into quadrants. The extension of blue ink along the metal‐ceramic crown/composite resin interface was measured linearly using image analyzer and then analyzed by three‐way ANOVA and independent t‐test with a Mann‐Whitney test. The level of significance was set at p < 0.05. Results: All tested subgroups demonstrated different levels of microleakage. There was no significant difference related to restorative technique; however, there was a significant difference related to water storage and thermocycling. Conclusions: All tested techniques and materials in this study showed microleakage. Packable composite while a flowable liner showed a marginally better result than packable composite alone. Excessive thermocycling resulted in significant differences among the test groups.     

Microleakage of different resin composite types.

OBJECTIVE: The purpose of this study was to evaluate the microleakage of Class V cavity preparations restored with three different types of resin composite and an ormocer. METHOD AND MATERIALS: Forty Class V cavities were prepared in buccal and lingual surfaces of 20 recently extracted molar teeth. The occlusal margin of each restoration was on enamel and the gingival margin on dentin. Teeth were randomly assigned to four groups of 5 teeth each and restored as follows: Group I, flowable resin composite (Tetric Flow); Group II, hybrid resin composite (Z100); Group III, packable resin composite (Solitaire 2); Group IV, organically modified ceramics-ormocer (Admira). In all groups, the manufacturers' instructions were strictly followed. All restorative resin composite materials were placed in one increment. All teeth were then immersed in 0.5% basic fuchsin solution for 24 hours after thermocycling (200 cycles; between 4 degrees C to 60 degrees C). The teeth then were longitudinally sectioned and observed under a stereomicroscope. The degree of dye penetration was recorded and analyzed with the Kruskal-Wallis and Mann-Whitney tests. RESULTS: No statistically significant differences in microleakage were observed between groups either on enamel or dentin. CONCLUSION: All restorative materials demonstrated equal effectiveness in reducing microleakage.     

冷光漂白对树脂-牙釉质微拉伸强度及边缘微渗漏的影响

目的：探讨冷光漂白对树脂-牙釉质微拉伸强度、界面微观形态及V类洞边缘微渗漏的影响。方法：30颗离体前磨牙随机分为5组,每组6颗牙。P组：未漂白;P0组：漂白后即刻;P1组：漂白后储存于人工唾液1周;P2组：漂白后储存于人工唾液2周;P3组：漂白后储存于人工唾液3周。各组Z-350树脂修复,进行微拉伸实验及扫描电镜观察。另30颗离体磨牙进行V类洞微渗漏实验,分组同上,每组6颗牙,定为S、S0、S1、S2、S3组。SPSS13.0软件包进行统计学处理。结果：P、P2、P3组微拉伸强度显著高于P0组（P〈0.05）,P2、P3组微拉伸强度显著高于P1组（P〈0.05）,其余各组均无显著差异。扫描电镜观察树脂-釉质界面,P0组存在缝隙,P1、P2、P3组界面逐渐致密。S、S2、S3组牙合壁微渗漏值显著低于S0组（P〈0.05）,各组龈壁微渗漏无显著差异。组内比较：除S组外,其余4组龈壁微渗漏均显著大于牙合壁（P〈0.05）。结论：冷光漂白后不适合进行即刻树脂修复,树脂修复最佳时间是漂白后2周。