酸蚀时间对牙本质粘结界面纳米渗漏的影响

目的：观察、比较不同酸蚀时间对4种全酸蚀粘结剂（OptiBond Solo（0B）、singleBond（SB）、One-Step（0S）、Prime＆BondNT（PB））牙本质粘结界面纳米渗漏的影响。方法：选取64颗无龋坏人磨牙，用600目碳化硅砂纸在流水冲洗下预备出统一的牙本质粘结面玷污层，分别选用4种粘结剂在不同粘结面酸蚀时间条件下进行粘结处理；每颗牙齿垂直于粘结面切割出4个4mm×0．9mm×4mm粘结试件，分别在TEM下观察、比较其粘结界面纳米渗漏。结果：4种粘结剂的牙本质粘结界面纳米渗漏均随酸蚀时间的延长而增加。结论：延长酸蚀时间，在牙本质粘结界面中遗留有更多的未封闭结构，加速牙本质粘结界面老化。     

粘结面润湿度对牙本质粘结界面纳米渗漏的影响

目的：观察、比较不同粘结面润湿度对4种全酸蚀粘结剂（OptiBond Solo（OB）、Single Bond（SB）、One-Step（OS）、Prime＆Bond NT（PB））牙本质粘结界面纳米渗漏的影响。方法：选取36颗无龋坏人磨牙，用600目碳化硅砂纸在流水冲洗下预备出统一的牙本质粘结面玷污层。分别用4种全酸蚀粘结剂在不同粘结面润湿度条件下进行粘结处理。每颗牙齿垂直于粘结面切割出4个4mm×0．9mm×4mm粘结试件，避光贮存于氨化硝酸银溶液中24h，在TEM下观察、比较牙本质粘结界面纳米渗漏．结果：不同的粘结面润湿度条件下，4种全酸蚀粘结剂牙本质粘结界面中均可以观察到不同程度的纳米渗漏。结论：粘结面润湿度对含不同有机溶剂粘结剂的牙本质粘结界面纳米渗漏的影响程度不同。     

人工唾液浸泡对牙本质粘结界面纳米渗漏的影响

目的：探讨含细菌的人工唾液对牙本质粘结界面纳米渗漏的影响。方法：选用全酸蚀粘结剂Prime Bond NT（NT）与正常牙本质粘结，制备微拉伸试件。将试件浸泡于含细菌的人工唾液中，分别在即刻、1周、1月、3月时取出，用扫描电镜（SEM）观察粘结界面银沉积情况，并用N1H图像分析软件量化处理，以界面银沉积面积占断裂界面的百分比来评价纳米渗漏程度。结果：粘结界面在即刻、1周、1月、3月时的银沉积面积百分比分别为10．97±5．14、12．25±4．01、16．49±4．43、21．03±5．65。结论：无论浸泡与否，粘结试件都无法避免纳米渗漏的产生；含细菌的人工唾液浸泡使得粘结系统粘结界面纳米渗漏增加，并且银沉积量随着时间的延长而增大。     

酸蚀时间对牙本质粘结强度的影响

目的：研究比较不同酸蚀时间对4种全酸蚀粘结剂（OptiBond Solo（OB）、Single Bond（SB）、One—Step（OS）、Prime＆BondNT（PB））牙本质粘结强度的影响。方法：选取32颗无龋坏人磨牙，用600目碳化硅砂纸在流水冲洗下预备出统一的牙本质粘结面玷污层，分别选用4种粘结剂在不同粘结面酸蚀时间条件下进行粘结处理；每颗牙齿垂直于粘结面切割出8个（1．0×1．0×4．0）mm^3粘结试件，分别进行微拉伸强度（μTBS）测试。结果：4种粘结剂OB（25．36±4．18）MPa、SB（24．25±3．97）MPa、OS（28．65±4．93）MPa和PB（27．12±4．13）MPa在酸蚀粘结面15S时均取得了最高的牙本质粘结强度（P〈0．01）。结论：不同酸蚀时间对不同粘结剂牙本质粘结强度的影响不同。     

粘结面润湿度对牙本质粘结强度的影响

目的：研究、比较不同粘结面润湿度对4种粘结剂（OptiBond Solo（OB）、Single Bond（SB）、One-Step（OS）、Prime＆Bond NT（PB））牙本质粘结强度的影响。方法：选取36颗无龋坏人磨牙，用600目碳化硅砂纸在流水冲洗下预备出统一的牙本质粘结面玷污层。分别用4种全酸蚀粘结剂在不同粘结面润湿度条件下进行粘结处理。每颗牙齿垂直于粘结面切割出8个1.0mm×1.0mm×4.0mm粘结试件，分别进行微拉伸强度（μTBS）测试。结果：4种粘结剂OB（25.24±2.07）MPa、SB（24.28±4.73）MPa、OS（28.29±4.35）MPa和PB（26.87±4.39）MPa在润湿的牙本质粘结面上均取得了最高的牙本质粘结强度（P〈0.01）。结论：不同粘结面润湿度对不同溶剂粘结剂牙本质粘结强度的影响不同。     

“劲润”牙本质保护膜的牙本质粘结性能探讨

目的：探讨“劲润”牙本质保护膜（Hybrid Coat,HyC）的牙本质粘结性能。方法：选取A组（HyC）和其他3组不同类型的牙本质粘结剂：B组（G-Bond）、C组（MegaBond）和D组（single Bond）,比较其对牛牙牙本质的剪切粘结强度,并用实体显微镜观察粘结界面断裂模式。各组试料数分别为n=10,结果通过Tukey-Kramer（P〈0．05）进行统计学分析。结果：B、C、D组均显示了较大的粘结强度,3组之间无统计学差异。A组（HyC）显示了较低的粘结强度,约10．08MPa,与其他3组之间存在显著性差异。断裂模式显示,A组（HyC）以界面破坏为主,而其他3组以凝集破坏和混合破坏为主。结论：本研究结果提示,“劲润”牙本质保护膜（HyC）的粘结强度弱于其他3组牙本质粘结剂。为了保证HyC长期稳定的防过敏效果及粘结性能,在今后的研究中有必要进一步探讨如何提高HyC的牙本质粘结性能。     

空气喷砂技术制洞对树脂粘结界面微渗漏的研究

目的：观察空气喷砂技术制洞对树脂粘结界面微渗漏的影响。方法：分别运用空气喷砂和传统涡轮机制洞、两种粘结体系进行牙本质粘结,采用染料渗入法观察粘结界面的微渗漏情况。结果：自酸蚀组微渗漏程度低于全酸蚀组,空气喷砂制洞组微渗漏程度低于涡轮机制洞组,酸蚀组微渗漏程度均低于未酸蚀组。结论：空气喷砂技术制洞树脂粘结界面微渗漏情况优于传统涡轮机制洞。     

两种漂白方法对牙本质与树脂粘结强度影响的实验研究

目的：比较牙本质经两种漂白方法漂白后,在不同时间粘结树脂其抗剪强度变化。方法：25颗恒前磨牙随机分为5组。A组为对照组：人工唾液内3周后制备牙本质粘结面,粘结树脂;B组：牙齿外漂白每天6h,共3周后制备牙本质粘结面,粘结树脂;C组：牙齿外漂白3周,人工唾液内储存2周后制备牙本质粘结面,粘结树脂;D组：牙齿内漂白3周后制备牙本质粘结面,粘结树脂;E组：牙齿内漂白3周,人工唾液内储存2周后制备牙本质粘结面,粘结树脂。电子万能实验机测试剪切粘结强度。结果：①抗剪强度测试结果：A组（18.61±3.56）MPa,B组（10.74±3.03）MPa,C组（17.21±3.15）MPa,D组（12.10±2.64）MPa,E组（16.78±2.84）MPa;②统计学分析：A-E组试件的剪切强度值单因素方差分析（one-wayANOVA）表明5组样本均数之间存在统计学差异（P〈0.05）。各组均数两两比较（Student-Newman-Keuls,SNK-q法）显示A与B组,A与D组,B与C组,D与E组的剪切强度值差别有统计学意义（P〈0.05）,而A与C组,A与E组,B与D组,C与E组的剪切强度值之间无统计学差异（P〉0.05）。结论：①两种漂白方法对牙本质与树脂粘结强度的影响无明显差别;②牙齿漂白后即刻粘结树脂,两种漂白方法均会降低牙本质与树脂的粘结强度;③牙齿漂白后延迟2周再粘结树脂,两种漂白方法均能够恢复牙本质与树脂的粘结强度接近未漂白组的水平。     

酸蚀时间对临床托槽粘结效果的影响

目的：比较10s和60s酸蚀后临床托槽脱落率的差异,从而探讨正畸临床适宜的牙釉质酸蚀处理时间.方法：选择年龄为10～18岁的正畸患者30名,随机分为两组,两组患者按不同牙位分别进行两种时间的酸蚀.酸蚀后常规粘结托槽,每次复诊时分别记录两组托槽脱落数,连续记录6个月.结果：10s酸蚀组总脱落率为8.4%,60s酸蚀组总脱落率为3.2%,前牙托槽脱落数明显少于后牙,最易脱落的托槽为第二前磨牙.结论：建议正畸临床上粘结前牙可使用10s的酸蚀时间.第二前磨牙及腭向错位侧切牙宜适当延长酸蚀时间.     

低温常压等离子体改善牙本质-全酸蚀粘接系统粘接效果的体外研究

目的:本研究拟观测低温常压等离子体射流处理对牙本质-全酸蚀粘接系统粘接效果及牙本质胶原纤维耐NaC10降解的效果.方法:离体牙去除面牙釉质,暴露的牙本质打磨后酸蚀15s并冲洗,随后用NTAPP射流分别处理牙面0、5、10、15、20s,常规制作微拉伸粘接试件,每组有一半试件冷热循环10 000次,分别检测各组循环前后...     

Influence of etching time on bond strength in dentin irradiated with erbium lasers

The purpose of this in vitro study was to evaluate the effect of etching time on the tensile bond strength (TBS) of a conventional adhesive bonded to dentin previously irradiated with erbium:yttrium–aluminum–garnet (Er:YAG) and erbium, chromium:yttrium–scandium–gallium–garnet (Er,Cr:YSGG) lasers. Buccal and lingual surfaces of 45 third molars were flattened until the dentin was exposed and randomly assigned to three groups (n?=?30) according to the dentin treatment: control (not irradiated), irradiated with Er:YAG (1 W; 250 mJ; 4 Hz; 80.6 J/cm²) laser or Er,Cr:YSGG (4 W; 200 mJ; 20 Hz; 71.4 J/cm²) laser, and into three subgroups (n?=?10) according to acid etching time (15 s, 30 s or 60 s) for each experimental group. After acid etching, the adhesive was applied, followed by the construction of an inverted cone of composite resin. The samples were immersed in distilled water (37°C for 24 h) and subjected to TBS test [50 kilogram-force (kgf), 0.5 mm/min]. Data were analyzed by analysis of variance (ANOVA) and Tukey statistical tests (P?≤?0.05). Control group samples presented significant higher TBS values than those of all lased groups. Both irradiated groups exhibited similar TBS values. Samples subjected to the different etching times in each experimental group presented similar TBS. Based on the conditions of this in vitro study we concluded that Er:YAG and Er,Cr:YSGG laser irradiation of the dentin weakens the bond strength of the adhesive. Moreover, increased etching time is not able to modify the bonding strength of the adhesive to irradiated dentin.     

Effect of acid and laser etching on shear bond strength of conventional and resin-modified glass-ionomer cements to composite resin

Success in sandwich technique procedures can be achieved through an acceptable bond between the materials. The aim of this study was to compare the effect of 35% phosphoric acid and Er,Cr:YSGG laser on shear bond strength of conventional glass-ionomer cement (GIC) and resin-modified glass-ionomer cement (RMGIC) to composite resin in sandwich technique. Sixty-six specimens were prepared from each type of glass-ionomer cements and divided into three treatment groups as follows: without pretreatment, acid etching by 35% phosphoric acid for 15 s, and 1-W Er,Cr:YSGG laser treatment for 15 s with a 600-μm-diameter tip aligned perpendicular to the target area at a distance of 1 mm from the surface. Energy density of laser irradiation was 17.7 J/cm². Two specimens in each group were prepared for evaluation under a scanning electron microscope (SEM) after surface treatment and the remainder underwent bonding procedure with a bonding agent and composite resin. Then the shear bond strength was measured at a crosshead speed of 0.5 mm/min. Two-factor analysis of variance and post-hoc Tukey test showed that the cement type, surface treatment method, and the interaction of these two factors significantly affect the shear bond strength between glass-ionomer cements and composite resin (p < 0.05). Surface treatment with phosphoric acid or Er,Cr:YSGG laser increased the shear bond strength of GIC to composite resin; however, in RMGIC only laser etching resulted in significantly higher bond strength. These findings were supported by SEM results. The fracture mode was evaluated under a stereomicroscope at ×20.     

Tensile bond strength of sealants following Er:YAG laser etching compared to acid etching in permanent teeth

The aim of this in vitro study was to assess the effect of Er:YAG laser surface treatment on the tensile bond strength of a sealant in permanent teeth. A total of 30 sound third molars were selected and embedded in cold-cure acrylic resin. The enamel surfaces were flattened by a grinding. The teeth were randomly divided into three groups and pretreated as follows: (1) 37% phosphoric acid; (2) Er:YAG laser (1.5 ml/min water spray, 100 mJ energy output, 10 Hz frequency, focal distance 17 mm); (3) Er:YAG laser + 37% phosphoric acid. The treated surfaces were isolated by double adhesive Sellotape and after insertion of a split Teflon matrix at an isolated site, sealant was applied. The specimens were thermocycled and stored at 37°C in distilled water for 72 h, then subjected to a tensile bond strength test (50 kgf at 0.5 mm/min). The mean tensile bond strengths (±SD, in megapascals) were: 18.51±5.68 in group 1, 8.06±2.69 in group 2, and 17.33±5.04 in group 3. Data were submitted to analysis of variance and the Tukey test. No significant difference were found between groups 1 (37% phosphoric acid) and group 3 (Er:YAG laser + 37% phosphoric acid) but treatment with the Er:YAG laser alone (group 2) resulted in significantly lower tensile bond strength than seen in the other groups. In this setting, the Er:YAG laser prepared the enamel surface for sealing but did not eliminate the need for acid etching before sealant application.     

Effect of Er:YAG laser on bond strength to dentin of a self-etching primer and two single-bottle adhesive systems

BACKGROUND AND OBJECTIVES: To assess the effect of erbium:yttrium aluminium garnet (Er:YAG) laser on bond strength to dentin of a self-etching primer (Clearfil Liner Bond 2V, CL2V) and two single-bottle agents (Excite, EX; Gluma One Bond, GB). STUDY DESIGN/MATERIALS AND METHODS: Thirty human molars were selected, roots were removed and crowns were bisected, providing 60 halves. Specimens were included and ground to expose dentin. Bonding site was limited and samples were assigned to three groups: I, CL2V; II, EX; III, GB. Dentin was either conventionally treated or submitted to laser conditioning + conventional treatment. The adhesive protocol was performed, samples were stored for 24 hours and bond strength was tested to failure (0.5 mm/min). RESULTS: Statistical analysis showed a decrease in bond strength for lased subgroups and this drop was more evident for EX. CL2V provided the best overall results, regardless of the surface treatment. CONCLUSIONS: Er:YAG laser may adversely affect bond strength in higher or lesser degree, depending on the adhesive system used.     

Selective targeting of protein, water, and mineral in dentin using UV and IR pulse lasers: the effect on the bond strength to composite restorative materials

BACKGROUND AND OBJECTIVES: Previous studies have shown that during the laser irradiation of dentin and bone, thermal damage can be minimized by using a highly absorbed laser wavelength, laser pulses shorter than the thermal relaxation time of the deposited laser energy at that wavelength, and the addition of a layer of water to the tissue surface before ablation. The objective of this study was to investigate the influence of laser pulse duration and wavelength with and without the added water layer on the bond strength of composite to laser prepared dentin surfaces. The specific hypothesis that was tested was that thermal damage to the collagen matrix in dentin compromises the bond strength to composite restorative materials. STUDY DESIGN/MATERIALS AND METHODS: Three laser systems were employed that were tuned to water, collagen, and mineral absorption with pulse durations less than the thermal relaxation time of the deposited energy. The surfaces of human dentin were irradiated by laser irradiation from free-running and Q-switched Er:YSGG lasers, pulsed CO(2) lasers operating at 9.6-microm, and a Q-switched Nd:YAG laser operating at 355-nm. A motion control system and a pressurized spray system incorporating a microprocessor controlled pulsed nozzle for water delivery, were used to ensure uniform treatment of the entire surface. Shear bond testing was used to evaluate the adhesive strength in order to access the suitability of laser treated surfaces for bonding. Bonded interfaces were examined by SEM. RESULTS: All the laser groups had significantly lower bond strengths than the positive acid etch control group. The highest bond strengths were for the short pulse (< 5-microsecond) Er:YSGG and CO(2) laser groups with water. Laser groups without water had significantly reduced bond strengths and thicker layers of thermally damaged dentin. CONCLUSIONS: Thermal damage to the collagen matrix profoundly influences the bond strength to composite restorations.     

The influence of Er:YAG laser conditioning versus self-etching adhesives with acid etching on the shear bond strength of orthodontic brackets

OBJECTIVE: The aim of this study was to compare the shear bond strength (SBS) of orthodontic brackets after acid etching, laser ablation, self-etching primer application, and combined treatments. METHODS: One hundred defect-free premolars were randomly assigned to five groups. The teeth received the following treatments: group 1: phosphoric acid + Transbond XT primer; group 2: Transbond Plus Self-Etching Primer (TPSEP); group 3: Er:YAG laser ablation + Transbond XT primer; group 4: Er:YAG laser ablation + phosphoric acid + Transbond XT primer; and group 5: Er:YAG laser ablation + TPSEP. Transbond XT Adhesive Paste was used in all groups for bracket bonding. Samples were stored in deionized water at 37 degrees C for 24 h. The shear debonding test was performed at a crosshead speed of 5 mm/min. Failed brackets were examined by a stereomicroscope at 16 x magnification to determine the bond failure interface using a modified adhesive remnant index (ARI). SBS values were compared using one-way analysis of variance (ANOVA). The Kruskal-Wallis test was used for ARI scores and pairwise comparisons were done using the Mann-Whitney U test with Bonferroni correction. RESULTS: Mean SBS values (MPa) and standard deviations for the groups were: group 1, 13.18 +/- 3.45; group 2, 13.52 +/- 4.38; group 3, 10.33 +/- 4.74; group 4, 13.00 +/- 3.47; and group 5, 12.46 +/- 6.31. No significant differences were observed in the SBS of all the groups evaluated, but there was a significant difference in ARI scores, with group 3 showing higher ARI scores than groups 1 and 4. CONCLUSIONS: Er:YAG laser ablation and self-etching primer application showed similar SBS values as conventional acidetching for bonding brackets.