配色颜料-硅橡胶复合体的敏感试验

目的：研究油画类赝复配色颜料加入硅橡胶后对皮肤的致敏性能。方法：豚鼠皮内注射试验试液，经诱发和加强及过敏激发后，观察局部组织的过敏现象。结果：20只豚鼠均未见有明显红斑或水肿发生，评定配色颜料一硅橡胶复合体的小鼠皮肤过敏率为0％。结论：油画类配色颜料加入硅橡胶后具有良好的生物安全性，短期或长期应用于口腔环境将不致引起过敏反应的发生。     

模拟日光老化下油画颜料着色赝复体硅橡胶褪色过程的初步研究

目的研究不同浓度镉红油画颜料着色MDX4-4210赝复体硅橡胶的褪色过程,为临床赝复体的比配色提供指导。方法模拟日光老化条件下,以MDX4-4210硅橡胶为基质,硅铝包覆纳米TiO2为遮色剂,镉红油画颜料为着色剂,观察4种浓度(0.05%、0.1%、0.2%、0.4%)镉红油画颜料着色赝复体硅橡胶的褪色过程。结果 4种浓度镉红油画颜料着色赝复体硅橡胶的△E、△L、△a、△b值均有统计学差异(P<0.05),且变化主要集中在第一次照射,之后变化量逐渐减小。结论镉红油画颜料着色硅橡胶随着模拟日光照射时间的延长逐步褪色,且早期变化最显著。镉红油画颜料浓度增加,减少了色差变化,起到了抗模拟日光照射褪色的作用。     

热固化下油画颜料着色硅橡胶的色度稳定性研究

目的:对热固化条件下的油画颜料耐热性能和化学稳定性进行评价.方法:测定80℃热固化,固化时间90 min与室温固化23℃,固化时间24 h两组油画颜料着色的硅橡胶试样的色度值(Lab),并计算试样间的色差值(△E).结果:热固化试样的色度值为:61.1,12.3,10.8;对照组为:60.9,12.1,10.7;两者之间的色差为AE=0.3.结论:油画颜料着色硅橡胶在热固化过程中具有良好的色度稳定性.油画颜料可以作为适宜的赝复配色颜料.     

配色颜料-硅橡胶复合体的细胞毒性试验和溶血试验

目的：研究油画类赝复配色颜料加入SY-1硅橡胶后的细胞毒性和溶血性能。方法：采用分子滤过法对颜料一硅橡胶复合体进行细胞毒性评价；采用分光光度计测定由试验材料所引起的新鲜抗凝兔血细胞红细胞溶解和游离血红蛋白程度。结果：在复合体与细胞材料相接触区域试验滤纸的外观呈现蓝染，与其它单层细胞区域相比较，染色密度无差异。细胞毒性评级为0级；复合体溶血率小于5％，不会引起急性溶血。结论：配色颜料-硅橡胶复合体在细胞毒性和急性溶血方面，具有良好的生物安全性。     

MDX-4-4210硅橡胶计算机配色的全光谱匹配法研究

目的:尝试应用全光谱匹配法实现MDX-4-4210硅橡胶的计算机配色.方法:以MDX-4-4210硅橡胶为基质,选用经分离、纯化的油画类颜料作为添加颜料,制备镉红、镉黄、蓝、褐、钛白和铁黑6个系列的单色梯度浓度样品和靶目标样(肤色色样),用FMC-9204型光谱测色仪分别采集6种单色梯度浓度样和靶目标样的光谱数据,并用自编配色软件进行全光谱匹配计算,得到匹配靶目标样的颜料浓度配比数据,进行相同工艺的配色样制备,最后将配色样与靶目标样的色度进行对比评价.结果:6个单色颜料系列的光谱反射率随颜料浓度加深,呈现较好的递减规律.根据全光谱配色软件计算的颜料浓度配比数据,从而制备的配色样与靶目标样的色度值基本接近,色差在1.8620～3.0792之间.结论:应用全光谱匹配法能够实现MDX-4-4210硅橡胶的计算机配色,其配色色差可以满足赝复体的临床色差要求,且配色效果优于三刺激值匹配法.     

配色颜料加入量对MDX-4-4210硅橡胶机械性能的影响

目的:探讨颜面赝复体配色颜料的适合加入量。方法:以MDX-4-4210硅橡胶为基质,按照国家标准要求,以未添加颜料的MDX-4-4210硅橡胶为对照,在相同条件下,对添加镉黄颜料浓度分别为0.1、0.15、0.2、0.25和0.3wt%的MDX-4-4210硅橡胶进行拉伸性能、撕裂性能和硬度等机械性能测定,采用SPSS10.0软件包对结果进行统计学分析。结果:随着颜料添加量的增多,MDX-4-4210硅橡胶扯断强度、扯断伸长率、撕裂强度和硬度均下降,各组之间有显著性差异;而永久变形率(3min后)几乎不发生改变,各组之间的差别无显著性,即硅橡胶的弹性性能相对稳定。结论:配色颜料加入量能够改变硅橡胶的机械性能。当颜料浓度大于或等于0.2wt%时,其机械性能发生显著变化。     

不同厚度硅铝包覆纳米TiO_2盖膜对赝复体硅橡胶色彩稳定性的影响

目的研究不同厚度硅铝包覆纳米Ti O_2硅橡胶盖膜对MDX4-4210赝复体硅橡胶褪色过程的影响,探讨此方法对提高颜面赝复体硅橡胶色彩稳定性的有效性,并提供理论基础。方法模拟日光老化条件下,以MDX4-4210硅橡胶为基质,硅铝包覆纳米Ti O_2为遮色剂,镉红油画颜料为着色剂,观察比较高浓度镉红油画颜料硅橡胶主体加盖不同厚度(0、0.5、1.0 mm)硅铝包覆纳米Ti O_2硅橡胶膜试件老化前后L*a*b*值。结果不同厚度0.1%硅铝包覆纳米Ti O_2盖膜的试件ΔE、Δa随着厚度的增加ΔE、Δa逐渐减小,即总色差、红色褪色逐渐减小,有显著性差异(P<0.05)。而ΔL,Δb随着厚度的增加逐渐增大,即变暗、变黄的程度逐渐增大,有显著性差异(P<0.05)。结论加盖不同厚度硅铝包覆纳米Ti O_2硅橡胶膜的方法对延缓赝复体硅橡胶褪色具有一定的作用,为提高赝复体硅橡胶色彩稳定性提供了新思路。     

配色颜料及唾液对硅橡胶表面白色念珠菌粘附性的影响

目的:探讨赝复配色颜料及口腔唾液对MDX44210硅橡胶表面白色念珠菌(Candidaalbicans)粘附性的影响。方法:对MDX44210硅橡胶试样表面的C.albicans粘附数量进行计数,采用χ2检验和方差分析。结果:C.albicans的粘附数量在着色和未着色MDX44210硅橡胶材料组间无显著差异(P>0.05)。有唾液获得膜存在时,MDX44210硅橡胶表面的C.albicans粘附数量低于无唾液获得膜存在时(P<0.01)。结论:配色颜料对MDX44210硅橡胶的C.albicans表面粘附性能无影响,而口腔唾液有降低C.albicans粘附的作用。     

臭氧老化对SY-1硅橡胶色彩稳定性的影响

目的 :了解臭氧老化对内着色SY 1硅橡胶色彩稳定性的影响 ,以便为选用适宜的硅橡胶着色颜料提供理论依据。方法 :SY 1硅橡胶按所加色料不同分为 4组 (对照组、水粉颜料土黄色、油画颜料土黄色、无机盐类颜料中铬黄 ) ,按国家标准对其进行臭氧老化并测定老化前后L 、a 、b 值 ,据此计算△E值。结果 :经臭氧老化 72h ,对照组△E为 0 .5 5± 0 .11;水粉土黄组△E为 3 .5 5± 0 .0 9;油画土黄组△E为 1.40± 0 .11;中铬黄组△E为 1.5 7± 0 .0 7。结论 :SY 1硅橡胶在臭氧老化条件下 ,油画类颜料与无机盐类颜料色彩稳定性优于水粉颜料。     

MDX-4-4210硅橡胶计算机配色的三刺激值匹配法研究

目的：尝试应用三刺激值匹配法实现MDX-4-4210硅橡胶的计算机配色。方法：以MDX-4-4210硅橡胶为基质,选用经分离、纯化的油画类颜料作为添加颜料,制备镉红、镉黄、蓝、褐、钛白和铁黑6个系列的单色梯度浓度样品和靶目标样（肤色色样）,用FMC-9204型光谱测色仪分别采集6种单色梯度浓度样和靶目标样的光谱数据,并用自编配色软件进行三刺激值匹配计算,得到匹配靶目标样的颜料浓度配比数据,进行相同工艺的配色样制备,最后将配色样与靶目标样的色度进行对比评价。结果：6个单色颜料系列的光谱反射率随颜料浓度加深,呈现较好的递减规律。根据三刺激值配色软件计算的颜料浓度配比数据制备的配色样与靶目标样的色度值比较接近,色差范围为2.6584～3.5759。结论：应用三刺激值匹配法能够实现MDX-4-4210硅橡胶的计算机配色,但是获得的配色样色彩偏差较大,其配色精度仍需进一步提高。     

Ultraviolet radiation-induced color shifts occurring in oil-pigmented maxillofacial elastomers.

STATEMENT OF PROBLEM: Oil-based pigments are added to a maxillofacial prosthesis either as base colorants present within the elastomer or as surface tints that are painted on with an adhesive. Color stability of the pigments and pigmented prosthetic materials on exposure to ultraviolet radiation are unknown. PURPOSE: This study measured DeltaE* color changes caused by ultraviolet radiation for materials colored with 5 oil pigments, applied either as base colorants (intrinsic) or surface tints (extrinsic) to a silicone elastomer. MATERIAL AND METHODS: One of 5 oil pigments was added to polydimethyl siloxane disks to serve as a base colorant (0.2 weight percent present throughout a 2 mm thick disk) or as a concentrated surface tint (2.0 weight percent concentrated in upper 0.3 mm thickness). Pigmented disks, along with pigment-only and elastomer-only control disks, were exposed to ultraviolet radiation for 400, 600 and 1800 hours. DeltaE* color changes were measured at baseline and for each time interval. RESULTS: Control samples underwent minimum color changes after 1800 hours (DeltaE* 相似文献   

Allergy-related emergencies

Allergic reactions can develop to any of the drugs or materials commonly used in dentistry. They exhibit a broad range of clinical signs and symptoms ranging from mild, delayed reactions to immediate and life-threatening reactions developing within seconds. Allergies usually manifest themselves in reactions that are related to histamine release in one of three ways: skin reactions, respiratory problems and anaphylaxis. Anaphylaxis is the most critical allergic reaction in the dental environment. Measures such as airway management, oxygen supplementation, antihistamine, adrenaline and corticosteroid medication, cardiopulmonary resuscitation and evacuation to the emergency room, may be necessary.     

电热聚合法对两种树脂基托挠曲强度的影响

目的研究电热聚合方法对义齿基托挠曲强度的影响。方法选择两种常用热凝义齿基托树脂材料,分别采用传统水浴法和电热聚合法制作样本。样本分组为日进水浴组、贺利氏水浴组、日进电热组、贺利氏电热组,每组10个样本。测量各样本的挠曲强度,并用环境扫描电镜进行断面观察。实验数值采用方差分析,α=0.05。结果各组样本的挠曲强度均符合相关要求,日进电热组的挠曲强度值最大为(93.28±4.80)MPa,与其他3组间差别有统计学意义(P<0.05);而其余3组间的比较均无统计学意义。各组样本断面形态存在明显差别。结论电热聚合方法对义齿挠曲强度并无显著影响,所制作样本均符合国家标准。     

Occupation-related allergies in dentistry

BACKGROUND: Allergies to natural rubber latex (NRL) were unknown in dentistry until 1987. That changed with the publication of a report documenting NRL-based anaphylaxis in a dental worker. This case and others prompted regulatory and manufacturing changes in rubber products and increased awareness throughout the profession. However, other common dental chemicals cause allergic reactions and irritation and often are handled with insufficient precautions. Although recognition of NRL allergy has improved, awareness of other potential allergens and irritants in dentistry still is limited. OVERVIEW: Recent research indicates that the prevalence of NRL protein allergy may be decreasing. In contrast, occupation-related dermatoses associated with other dental products may be more common. Encounters with bonding agents, disinfectants, rubber, metals and detergents can cause occupation-based irritant contact dermatitis and allergic contact dermatitis. These conditions may be found in more than one-quarter of dental and medical personnel. Therefore, dental-specific information about the recognition and management of allergic and irritant reactions is needed. CONCLUSIONS AND CLINICAL IMPLICATIONS: The prevalence of occupation-related dermatitis may be increasing in dentistry. Reducing exposure to potential irritants and allergens and educating personnel about proper skin care are essential to reversing this trend.     

5种着色剂对牙科氧化锆陶瓷色度的影响

目的:研究5种着色剂对牙科氧化锆陶瓷色度影响的规律,为量化着色剂的添加比例提供依据。方法:在纳米氧化锆粉体中掺入不同比例的5种着色剂,200MPa冷等静压成型,于高温烧结炉中烧结到1400℃并保温2h,将烧结体研磨至(1.0±0.1)mm厚。观察烧结体的色泽并用色度仪测试其色度值。结果:氧化铒(Er_2O_3)能够使氧化锆陶瓷呈红色,对烧结体的b*值和L*值无影响。氧化铈(CeO_2)和氧化镨(Pr_6O_(11))均能使氧化锆陶瓷呈黄色,而对烧结体的a*值和L*值无明显影响。氧化铁(Fe_2O_3)能使氧化锆陶瓷呈黄褐色,随着剂量的增加,a*和b*值均增大,L*值略有下降。氧化锰(MnO_2)能够有效降低氧化锆陶瓷烧结体的明度,对a*和b*值无明显影响。结论:5种梯度着色氧化锆陶瓷能够覆盖牙科陶瓷所需的色度范围,值得进一步的研究与开发。     

Penicillin-induced anaphylaxis in a patient under hypotensive anesthesia

Elective use of penicillin during hypotensive anesthesia for orthognathic surgery induced a nearly fatal anaphylactic reaction. The first symptom of anaphylaxis was increased inspiratory resistance to mechanical ventilation, followed by severe hypotension. The therapeutic management of anaphylaxis is discussed. Patients susceptible to reactions from the administration of B-lactam antibiotics can be identified through skin tests. Patients reactive to such antibiotics should be treated with alternate antibiotics or they should be desensitized prior to receiving penicillin.     

腮腺手术后继发性出血12例分析

目的 :探讨腮腺手术后继发性出血的原因和防治措施。方法 :1993 -2 0 0 2年间进行各类腮腺手术42 8例 ,对术后发生继发性出血的 12例临床资料进行分析总结。结果 :腮腺手术后继发性出血的发生率为 2 .75 % ,继发性出血多发生于术后 12h内 ( 91.67% ) ,其中创面渗血占 75 % ,小血管结扎线滑脱占 16.67% ,未查见明确出血点占 8.3 3 % ,临床表现为术区肿胀压痛、皮肤青紫瘀斑 ,敷料上有大量鲜血渗出。结论 :为防止术后继发性出血 ,术中止血应彻底 ,术后 12h内应密切观察切口肿胀及渗血情况 ,一旦有继发性出血发生应及时手术探查 ,重新止血。     

Coverage error of commercial skin pigments as compared to human facial skin tones

Objectives

It is unknown if present-day pigments used for intrinsic colouration of maxillofacial prostheses are representative of human facial skin tones. This study's purpose was to measure L*a*b* values of pigmented elastomers coloured by eleven skin tone pigments and determine coverage error (CE) when the pigments were compared to human facial lip and nose colour data.

Methods

11 skin tone pigments were combined at 0.1%, 1% and 10% by weight with A-2186 elastomer (n = 3). L*a*b* values were measured with a spectrophotometer and group means were used to calculate ΔE* colour differences with each L*a*b* value obtained for human nose and lip. Pigmented elastomer CEs were calculated for nose and lip. Results were compared to CEs for proposed shade guide colours obtained from clustering analyses of facial skin colours.

Results

L* values of pigmented elastomers generally were higher than those measured for nose and lip, whereas a* values were lower. CEs for pigmented elastomers were higher than those obtained from the proposed shade guide obtained from clustered skin measurements.

Conclusions

Overall, the current commercial elastomers appeared to be too white and not red enough to adequately match the skin tones of the subject population. Adjustments must be made to the existing pigmenting system in order to adequately match the skin colours of the study population.

Clinical significance

The creation of a shade guide and a collection of intrinsic pigments representing the realm of human facial skin colours would greatly decrease the time a patient must sit while the clinician is obtaining an acceptable colour match for the silicone to be used for processing the final prosthesis, thereby increasing both patient satisfaction and clinician productivity.     

Anaphylaxis: An Update

Anaphylaxis is a medical emergency. Virtually, any individual may develop hypersensitivity to any of the various formulations/substances used in dental practice and this necessitates all dental professionals to keep themselves updated with the latest guide-line on management of life threatening anaphylaxis. Guidelines by the World Allergy Organization for the assessment and management of anaphylaxis in 2011 are discussed.     

Dissertations 25 year after date 18. Skin colour and facial prosthesis

The traditional 'trial and error' methods for skin colour recording are not satisfactory. In 1982 a dissertation was published, titled 'Skin colour and facial prosthetics, a colorimetric study'. The dissertation was concerned with a clinical study of skin colour recording objectively in a random sample of 100 people, using subtraction colorimetry. Subsequently, facial prostheses were fabricated for a group of patients with a facial defect who had to undergo radiotherapy. From the results of the study the 3 following conclusions were drawn. Skin colour recording for producing a facial prosthesis need to be carried as close to the facial defect as possible. Alterations of skin colour are determined by light scattering in the skin as well as skin pigments. In patients with facial defects who have to undergo adjuvant radiotherapy, skin colour alterations are present until on average 13-14 weeks after completion of the radiotherapy and from that time point the skin colour remains rather stable. After publication of the dissertation, other research results demonstrated that light scattering in the skin, a sign of skin translucency, may be determined with a fiberoptic scattering meter (volume reflectometer). Using the fiberoptic scattering meter, a colour formula can be made, which by calculation shows the amount of pigments and scattering objects needed to produce the correct translucency and colour of a facial prosthesis. Currently, a small beam reflectometer is used for this purpose.