不同操作模式的加热恒温漂白对健康自然牙漂白效果的临床评价

目的对不同操作模式的加热恒温漂白效果进行临床评价。方法 12名受试者分2组接受2种不同操作模式的加热恒温漂白治疗,包括在一次就诊时连续漂白操作3次(A)以及分为3次就诊,间隔1天,每次就诊漂白操作1次(B)。以牙科色度计测定各次操作之后以及漂白术完成1周后受试者上中切牙的颜色参数值,并计算相应的白度值和色差值。结果不论何种操作模式,漂白术后牙色的L*值提高,b*值降低。操作模式A术后1周与B各次操作后及术后1周获得的色差值之间并无统计学差异。操作模式A术前与术后1周的白度值之间存在显著性差异。操作模式B术前与第1次、第2次、第3次及术后1周的白度值之间存在显著性差异。结论两种操作模式下加热恒温漂白均可导致健康上中切牙发生亮度增加以及蓝色转变的颜色变化。     

诊室加热恒温漂白对不同牙位自然牙漂白效果的临床评价

目的评价不同牙位的自然牙在诊室加热恒温漂白治疗后颜色改善的效果。方法按照纳入标准挑选6名受试者,采用隔天漂白操作3次,每次操作15 min的方式进行诊室加热恒温漂白,测量受试者右上中切牙、右上侧切牙和右上尖牙漂白操作前,第1、2、3次漂白操作后,以及术后1周和1月的L*、a*、b*颜色参数值,计算色差值和白度值。结果不同牙位漂白后的色差值及白度值差值不存在统计学差异(P>0.05),不同漂白阶段及术后1周、1月的色差值及白度值差值之间也不存在统计学差异(P>0.05)。结论不同牙位的自然牙在诊室加热恒温漂白治疗后颜色改善的效果无明显差异。     

分光光度比色仪对牙齿漂白效果的分析

目的 采用分光光度比色仪分析牙齿漂白后不同部位颜色CIE L*、a*、b*值的变化。方法 选择67个健康完整的上颌中切牙,颜色大于A3（Vita经典比色板）。分光光度比色仪比色,记录颈部、体部、切端牙色。进行诊室漂白治疗（35%H2O2协同冷光漂白仪）后再次记录各部位牙色,计算ΔE、ΔL*、Δa*、Δb*和治疗有效率。对数据进行方差分析、配对t检验和Pearson相关分析。结果 治疗有效率分别为：颈部86.6%,体部86.6%,切端85.1%。ΔE均值：颈部5.09,体部4.44,切端4.40。漂白后L*值升高,a*和b*值降低,均有统计学差异（P<0.01）。颈部和体部基线b*值与ΔE成正相关。结论 35%H2O2协同冷光漂白仪照射有较好的牙齿漂白效果,顺序为颈部>体部>切端。颈部黄色降低幅度最大,切端明度增加最多。基线b*值越高,色差越大。     

上海地区汉族青年人群恒前牙体部颜色特征临床研究

目的:研究中国上海地区汉族青年人群恒前牙体部颜色特征.方法:132例20-35岁青年志愿者纳入研究,男性49例,女性83例;前牙发育正常,牙体完整,活髓,牙面清洁,无色素沉着、软垢、牙石,无前牙漂白史,使用OLYMPUS Crystaleye电子比色仪进行测量,共获得1584颗上下颌恒前牙体部的颜色参数L*、a*、b*值,按照上下颌中切牙、侧切牙、尖牙不同牙位分组,进行统计分析(t检验和单因素方差分析).结果:青年人群前牙体部色度范围为L*:71.54±4.13,a*:2.11±1.30,b*:19.29±4.02;上颌前牙体部色度范围L*:71.00±3.18,a*:2.33±1.41,b*:20.00±3.81,下颌前牙体部色度范围L*:72.28±3.19,a*:1.89±1.12,b*:18.62±4.00,上下颌前牙体部色差△E为1.93.上中切牙体部色度值参数为L*:73.06±2.60,a*:1.39±1.08,b*:17.71±3.13,下中切牙体部色度值参数为L*:73.14±3.34,a*:1.21±0.87,b*:15.40±2.63;上侧切牙体部色度值参数为L*:70.52±3.29,a*:1.98±0.94,b*:18.97±2.93,下侧切牙体部色度值参数为L*.72.15±3.56,a*:1.64±0.86,b*:17.94±2.76;上尖牙体部色度值参数为L*:69.41±2.42,a*:3.61±1.14,b*:23.28±2.83,下尖牙体部色度值参数为L*:71.58±2.37,a*:71.58±2.37,b*:22.42±2.86.中切牙、侧切牙、尖牙体部色度值之间差异均有统计学意义(P＜0.05).同颌左右同名牙之间差异无统计学意义(P＞0.05),而上下颌同名牙之间差异有统计学意义(P＜0.05).结论:青年人群前牙中中切牙明度最大,其次为侧切牙,尖牙明度最低,色相与彩度则相反,由中切牙至尖牙逐渐增加,颜色渐偏黄、红.比色时应注意前牙列的变化规律和上下颌前牙颜色的差异性.     

烧结次数对两种钛瓷粉颜色的影响

目的研究牙科钛表面烤瓷烧结次数对钛烤瓷修复体颜色的影响,以指导技工和临床烤瓷操作,同时比较两种瓷粉的颜色在烧结中的稳定性能是否存在差异。方法采用Ti- 22和Vita Titankeramik两种钛瓷粉,设计制作钛瓷标准试件,包括遮色瓷、体瓷和钛- 遮色瓷- 体瓷试件,经1、3、5、7、9次烧结处理,每次烧结后采用ShadeEye NCC比色仪,根据CIE1976L*a*b*色度系统标准测量各样本的L*a*b*值,并计算色差值、彩度和色调角,进行统计分析。结果烧结5次以内,各组试件的L*a*b*值及彩度、明度、色差及色调角均无明显变化,继续烧结后两种瓷粉的L*a*值均发生变化,且有统计学差异（P<0.05）。经过9次烧结,各组试件的色差变化均小于1.5。结论烧结次数在5次以内,钛瓷的颜色无明显变化,继续烧结则出现颜色差异,但肉眼尚未能辨别。     

汉族青年人群前牙色度分析的临床研究

目的：研究汉族青年人群前牙颜色特征。方法：使用OLYMPUS Crystaleye电脑比色仪测量148例18?35岁汉族青年共1769颗上下颌前牙颈、体、切端的L*、a*、b*值,使用SPSS 19?0进行统计分析（ t检验和单因素方差分析）。结果：①青年人群前牙的牙颈部色度范围为L*：70?96±3?05,a*：4?19±1?30,b*：21?10±3?52;体部色度范围为L*：71?63±3?21,a*：2?13±1?30,b*：19?43±3?99;切端色度范围为L*：68?08±2?91,a*：1?25±1?23,b*：15?89±3?71。前牙颈部、体部、切端两两比较L*、a*、b*值均有统计学差异（ P＜0?05）。②中切牙、侧切牙、尖牙三者间颈、体、切部的L*、a*、b*值比较均有统计学差异（P＜0?05）。③左右同名牙之间,其颈、体、切部的L*、a*、b*值差异无统计学意义（P＞0?05）。上下颌之间同名牙颈、体、切部的色度值进行比较时,除中切牙体部L*值、切端L*值、侧切牙颈部a*值、切端a*值、切端b*值、尖牙颈部b*值、切端b*值之间无显著性差异外,其余差异均有统计学意义（P＜0?05）。结论：汉族青年人群前牙并非均一颜色,比色时应注意颈、体、切分区比色,并注意不同牙位的差异性。     

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提要：漂白治疗是针对牙齿颜色缺陷、改善牙齿颜色效果的治疗方式,合理运用漂白治疗,可以在对牙齿基本不造成损伤的前提下,帮助患者获得满意的治疗效果。漂白治疗是一种与“颜色定位”密切相关的治疗手段,医生需要对相关色彩学知识有一定了解。色彩是光刺激到人眼产生的视觉感受。色彩学的三要素是色相、明度和饱和度。色彩空间是表达颜色的假想空间,常用色彩空间包括孟塞尔表色系统、L*a*b*色彩空间、L*C*h色彩空间等。漂白前后牙齿颜色变化的最基本特点是明度升高、饱和度降低,色相变化不明显。评价漂白前后牙齿颜色变化的手段包括比色板比色评价法和比色仪比色评价法,其中 VITA Bleachedguide 3D-Master比色板是最理想的比色板系统,以Crystaleye为代表的全牙测色型比色仪则在漂白前后色彩评价工作中具有更明显的优势。     

137例老年人上前牙色度分析

目的:研究老年人上前牙的颜色特点.方法:采用Shade Eye-[2]NCC第2代电脑比色仪,检测137例老年人612颗活髓上前牙的L*、a*、b*值,与100例年轻人200颗活髓上前牙比较,应用SAS 6.0软件包对数据进行t检验.结果:老年组上前牙色度值范围为中切牙L*:71.2±6.22,a *:-0.97±1.12,b *:15.9±5.04;侧切牙L*:69.6±5.52,a *:-0.6±1.18,b *:13.9±4.15;尖牙L *:68.4±5.99,a *:-0.15±1.02,b *:19.6±4.87.左右同名牙L *、a *、b *值差异无显著性(P>0.05);中切牙、侧切牙、尖牙之间两两比较,L *、a *、b *值均有显著差异(P<0.05).中切牙L *值最大,侧切牙次之,尖牙最小;中切牙a *值最小,侧切牙次之,尖牙最大;侧切牙*b值最小,中切牙次之.尖牙最大.各牙位间的色差(△E),中切牙与侧切牙为2.945NBS,尖牙与中切牙为4.629NBS,尖牙与侧切牙为5.832NBS.青年组中切牙的L *、a *、b *的平均值分别为75.82、-0.11和12.68,尖牙的L *、a *、b *的平均值分别为72.07、1.22和17.92.老年组上前牙显示较小的L *值和a *值、较大的b *值(P<0.05).结论:老年人上前牙颜色特点为,中切牙较侧切牙及尖牙明亮;侧切牙的色彩较中切牙及尖牙浅;尖牙较切牙偏红、偏黄.与青年组相比,老年人前牙显示的色度更暗,红色减少,黄色增加.     

松风HALO比色板的色度分析

目的：研究松风HALO比色板比色片的颈部、体部、切端部色度分布规律,以利提高临床医师对比色板颜色的判断能力。方法：采用数码摄影和计算机技术对松风HALO比色板的牙颈部、牙体部、切端部进行测量,根据比色板体部、颈部、切端部的L*、a*、b*、C*值分别绘制A、B、C、D、R、VR各组色介的L－C曲线及其a*-b*散点分布图。结果：松风HALO比色板各组颜色排列具有一定的规律性,随着A、B、C、D、R、VR各组比色板色阶的增大,颈部、体部、切端部的L＊值呈递减趋势,a*、b*值呈递增趋势。结论：比色板各组颜色排列的序列性,有助于临床医师对比色板颜色的判断。新增加三组根部色和两组偏红色,有利于对牙周病患和具有偏红色牙齿的比色。     

目测法比色准确性的评估

目的:研究目测法比色的准确性.方法:采用Vitapan比色板对100颗上颌天然切牙进行比色,选定比色片标号.在CIE1976L*a*b*色度系统下,运用松风ShadeEye NCC电脑比色仪对天然牙和比色片进行颜色的测量和分析.结果:目测法比色所选色片与天然牙的色差为0.26～6.70,平均色差为1.78.比色片的明度值与天然牙的明度值有显著性的差异.结论:门诊医师所选比色片与天然牙间的颜色存在一定的差异.     

上颌过小侧切牙患者颌面形态特征的研究

目的 通过对上颌过小侧切牙患者X线头影测量分析,了解其颌面形态发育特征。方法 选取120例上颌过小侧切牙患者作为研究对象,分为两组：A组为Ⅰ型锥形侧切牙60例,B组为Ⅱ型过小牙60例,拍摄X线头颅侧位片,对其进行X线头影测量分析。结果 A组患者SNA、ANB、Ptm-A(mm)、U1-SN、L1-NB、UL-EP值减小,SNB、PP-GoGn、SN-MP、Y轴、U1-L1、U1-NA、L1-MP、Z角增大;B组SNB、PP-GoGn、SN-MP、SN-MP、Y轴、U1-L1、Z角值减小,ANB、L1-NB、L1-MP值增大,差异均有统计学意义（P<0.05）。结论 多数上颌Ⅰ型锥形侧切牙患者表现为上颌骨发育不足,上颌后缩;多数上颌Ⅱ型过小侧切牙患者表现为下颌骨发育不足,下颌后缩。两型过小侧切牙患者具有截然不同的颌面形态特征。     

微螺钉型种植体支抗对成人双颌前突患者的治疗效果分析

目的：探讨运用微螺钉型种植体支抗矫治双颌前突畸形患者的临床效果。方法选取62例因双颌前突畸形进行正畸治疗的成年患者,根据所选择治疗方法的不同,分为微螺钉型种植体支抗组（A组,27例）以及口外支抗组（B组,35例）,并对两组的治疗效果进行比较分析。结果 A组的治疗时间较B组明显缩短,差异有统计学意义（P＜0.05）;A组患者的上唇突度、下唇突度、上唇?E线、下唇?E线以及唇间隙治疗前后变化差值均大于B组,差异有统计学意义（P＜0.05）;A组患者的上切牙突度、下切牙突度、上中切牙角、下中切牙角、上牙槽突度以及下牙槽突度治疗前后变化差值均大于B组,差异有统计学意义（P＜0.05）。结论微螺钉型种植体支抗可为双颌前突畸形患者的矫治提供满意的支抗作用,其临床效果较口外支抗更好。     

尖牙扩大联合曲矫治拥挤病例的临床应用

目的　通过尖牙联合曲 (canineexpansionarchwire ,CEAW )矫治拥挤病例 ,研究矫治前后的牙颌变化情况 ,以丰富拥挤病例非拔牙的矫治方法。方法　选择上牙弓拥挤为Ⅲ度或Ⅲ度以上的 10例患者 (其中男 5例 ,女 5例 ) ,平均年龄 12 .2岁 ,上颌拥挤度平均为 9.12mm。用CEAW进行矫治 ,治疗前后均拍摄头颅定位侧位片 ,并采用配对t检验 ,分析比较矫治前后的X线头影测量结果。结果　①坐标系中 ,上颌第一磨牙牙冠远中点向后的移动、上齿槽缘点和上中切牙切缘点向前的移动均具有统计学意义 ( P <0 .0 5 )。②相对于腭平面 ,上颌第一磨牙牙冠远中点向后的移动、上齿槽缘点和上中切牙切缘点向前的移动均具有统计学意义 (P <0 .0 1)。③同时发现上颌第一磨牙明显后倾 (P <0 .0 1) ,而上颌切牙没有明显唇倾。结论　CEAW通过后倾磨牙、推磨牙向后可以迅速而有效地解除拥挤 ,有效地完成矫治     

Composite resin color change after vital tooth bleaching

Color change of composite resin was determined with the Minolta Chroma meter (CR-100) after four sessions of vital bleaching. Specimens of selected composite resin materials were subjected to vital bleaching (37% H3PO4/1 minute, then 30% H2O2/infrared light/30 minutes.) Specimens were stored in water between bleaching. Control specimens were used to determine the effects of water storage alone. Initial L*a*b* color readings were made on 24-hour hydrated specimens. Final L*a*b* readings were made on 24-hour hydrated specimens. Calculations were made for the delta E values for each specimen. Mean delta E values and standard deviations were obtained for each material. Two-way ANOVA and Newman-Keuls analyses showed significant (alpha = 0.05) color change for most bleached materials. Additionally, some materials had delta E values greater than 3. These were visibly lighter compared to their controls. Vital bleaching produced color change in most composites as measured with the Chroma meter. This technique may be used to lighten dark-colored or stained composite resin restorations.     

In vivo evaluation of color of primary teeth

PURPOSE: The purpose of this study was to evaluate the color of primary teeth. METHODS: A Vita Easyshade intraoral spectrophotometer was used to determine the color of primary teeth: (1) maxillary central incisors, canines, and first molars; and (2) mandibular central incisors, canines, and first molars. A total of 604 teeth were measured. Color difference was compared to DeltaE*=2.7 (mean=50:50 replacement point). Coverage error (DeltaE*cov) was calculated. RESULTS: Mean L*a*b*C*ho values for primary teeth were 82.5, 0.2, 18.3, 18.4, and 89.4 respectively. The most frequently chosen shades were A1 (46%), A2 (25%), and B2 (11%). Canines had the highest lightness. Maxillary canines had the lowest a* values, whereas mandibular primary incisors had the highest a* values. Molars were the most chromatic (having the highest b* values), followed by canines and primary incisors in decreasing order. Coverage error (DeltaEcov*) of Vitapan Classical was 4.2 (+/-1.9 SD). CONCLUSIONS: Among primary teeth, the widest ranges, in order, were recorded for: (1) lightness; (2) chroma; and (3) hue. Three Vitapan Classical shades were the best match for 82% of primary teeth. Color differences among the same patient's teeth underline the need for an individual approach in color matching and reproduction of primary teeth.     

EFFECTIVENESS OF HOME BLEACHING AGENTS IN DISCOLORED TEETH AND INFLUENCE ON ENAMEL MICROHARDNESS

Objectives:

This study evaluated the effectiveness of different home bleaching agents on color alteration and their influence on surface and subsurface microhardness of discolored bovine enamel.

Material and Methods:

Forty-five fragments of bovine incisors were randomly allocated into 3 groups (n=15) according to the bleaching agent: 10% carbamide peroxide gel (CP10), 16% carbamide peroxide gel (CP16) and 6.5%-hydrogen-peroxide-based strip (HP6.5). Before bleaching treatment, initial values of Knoop surface microhardness and color (CIEL*a*b*) were obtained and the fragments were artificially stained in hemolyzed rat blood. Then, bleaching treatments were performed over a 21-day period. Color changes (ΔE) were assessed at 7, 14 and 21 days, and final surface microhardness reading was done after 21 days. Thereafter, the fragments were bisected to obtain subsurface microhardness. Data were subjected to ANOVA and Tukey''s tests (α=5%).

Results:

Color changes produced by CP16 were similar to those of CP10, and the color changes produced by these materials were significantly superior to those produced by HP6.5. Color changes at 21 days were superior to 7 days and similar to 14 days. The time did not influence color changes for CP16, which showed similarity between the 14- and 21-day results. No statistically significant differences were found among the home bleaching agents for surface and subsurface microhardness.

Conclusions:

Microhardness of bovine enamel was not affected by the bleaching agents. The 16% carbamide peroxide gel was the most effective for bleaching the stained substrate.     

延安地区健康青少年上中切牙短根畸形的患病率

目的 了解延安地区健康青少年上中切牙短根畸形的患病率.方法 按照同一标准严格筛选出延安地区首次来延安大学附属医院要求牙齿矫正的健康青少年174例,观察其曲面断层片上中切牙牙根形态,测量其根冠比例,计算上中切牙短根畸形的患病率,对男性和女性样本间进行卡方检验,所有数据采用SPSS16.0统计软件包进行统计学分析.结果 延...     

Preoperative incisor inclination in patients with Class III dentofacial deformities treated with orthognathic surgery

Our aim was to evaluate cephalometrically the preoperative inclination of the incisors in a group of 50 patients with Class III dentofacial deformities whose immediate preoperative lateral cephalometric radiographs were analysed after they had been treated by maxillary advancement. The radiographs were hand-traced by the same operator who made the cephalometric analysis. Mean values for each measurement were compared with the normal values using Student's t-test (p<0.05). Results showed significantly increased inclination of the upper incisors, with a mean U1-NA angle of 27.58° and a mean U1-PP angle of 116°. The lower incisors were also inclined lingually, with a mean L1-NB angle of 22.53° and a mean IMPA of 83.13°. Thirty-five of the patients had labial inclination of the upper, and 28 lingual inclination of the lower, incisors. Mean inclinations of upper and lower incisors differed from the normal values, and the inclination of the lower incisors was more likely to be decompensated than that of the upper incisors.