定量光导荧光技术评价含氟牙膏抑制早期龋损效果的临床研究

目的评价定量光导荧光技术（QLF）用于纵向监测光滑面早期龋损矿物质含量变化的能力及用于评价不同氟化物抑制早期龋损效果差异的可能性。方法选取305名11～14岁上颌前牙有早期光滑面龋的中小学生，随机分为NaF组、MFP组和不含氟组，分别采用含NaF的牙膏、含Na2PO3F的牙膏（氟浓度均为1 450 mg/L）和不含氟的牙膏刷牙。拍摄受检者上颌前牙光滑面早期龋损基线、刷牙后3个月和6个月时的QLF照片并保存。使用软件QLF2.00g对病损进行分析，界定病损范围，得出每次检查的△F（荧光损失）、Area（病损面积）和△Q（总荧光损失量）。结果296名（97.05%）受检者完成了整个研究。QLF检查结果显示，3个月时，296名受检者上颌前牙光滑面早期龋损均出现不同程度的好转，3组光滑面早期龋损Area、△F和lg△Q的变化均无统计学差异（P>0.05）；6个月时，296名受检者上颌前牙光滑面早期龋损均较基线时出现明显的好转，NaF组、MFP组光滑面早期龋损Area、△F和lg△Q的变化有统计学差异（P<0.05），而NaF组与MFP组之间无统计学差异（P>0.05）。结论QLF作为一种定量诊断方法，能够用于纵向病变跟踪监测和评价不同龋病干预措施效果。     

定量光导荧光技术评价光滑面早期龋损再矿化时间的临床研究

目的:检测上颌前牙光滑面早期龋损发生再矿化的时间.方法:选取符合纳入标准的成都市11~14 岁上颌前牙有早期光滑面龋的中小学生24 名参加研究.将其分为使用含单氟磷酸钠(F 1.45 g/L)牙膏和使用不含氟牙膏2 组.对受试者进行相同的口腔健康教育及刷牙方法的培训.拍摄基线前牙光滑面早期龋QLF照片,以后每周拍摄受检者前牙光滑面早期龋的定量光导荧光技术(QLF)照片,连续8 周.使用软件QLF 2.00g对病损进行分析,界定病损范围,得出每次检查的ΔF(荧光损失)、Area(病损面积)和ΔQ(总荧光损失量).结果:对24 名受检者共101 处上颌前牙光滑面早期龋损进行了为期8 周的临床研究,2 组受检者的早期龋损均出现不同程度的好转,但2 组之间的差异没有统计学意义(P>0.05).结论:QLF所能检测到的光滑面早期龋损发生再矿化的时间为3 周;QLF难以在短期内(8 周内)对2 种牙膏的效果是否存在差异做出判断,使用QLF作为诊断手段的临床研究需要更长的时间.     

定量光导荧光技术在口腔医学中的应用

定量光导荧光技术（quantitative light—induced fluorescence，QLF）是一种能拍摄牙面的荧光图像并对图像龋损区矿物质丢失和病损范围大小进行定量分析的方法。该技术可以对未形成龋洞的早期釉质龋损牙面定量评价，也可对病损区脱矿和再矿化过程矿物质含量改变进行定量监测。现就QLF的技术背景、设备组成、技术优点、在龋病早期诊断和其他方面的临床应用，以及影响QLF技术的因素等方面综述。     

QLF法研究一种含氟涂料对离体牛牙釉质的抗酸性效果

目的：采用定量光导荧光系统观察含氟涂料对牛牙釉质的抗酸性效果。方法：20个新鲜拔除的牛前牙,于每个标本唇面建立4个2mm×2mm开窗,随机分为4组,分别用含氟涂料、含氟牙膏、1%氟化钠溶液、去离子水处理,然后浸泡在脱矿液中,分别于处理的第1,2,4,8d,采用QLF法检测各组标本的荧光损失量△F（%）和病变面积△P（mm2）,计算△Q（%,mm2）,并再次处理。结果：用含氟涂料处理的牛牙釉质龋标本,再矿化面积最多、△Q降低最大,且与其他处理组有显著差异（P〈0.05）。结论：同其它方法相比,含氟涂料有利于增进离体牛牙釉质的抗酸性。     

3种方法对上颌前牙早期脱矿病损诊断价值的比较

目的：比较定量光激发荧光（quantitative light—induced fluorescence,QLF）系统与数码照相、肉眼检查3种方法对上颌前牙早期脱矿病损的检出率。方法：对德阳市和资阳市300名12周岁中学生的1732颗上颌前牙清洁干燥后．肉眼检查是否存在上颌前牙早期脱矿病损,并拍摄QLF照片和数码照片进行分析。结果：经卡方检验得出,QLF系统对上颌前牙早期脱矿病损的检出率（24．08％）显著高于肉眼直接检查（20．61％）和数码照相（22．17％）,其差异均有统计学意义（P〈0．05）。结论：QLF系统是一种对早期脱矿病损较可靠、快速、安全、无损伤的诊断方法,值得推广使用。     

3种无氟儿童牙膏对乳牙早期釉质龋再矿化作用的体外研究

目的 探究3种市售无氟儿童牙膏即生物活性玻璃儿童牙膏、双黄连儿童牙膏、木糖醇儿童牙膏对乳牙早期釉质龋的再矿化作用。方法 应用离体乳牙制备人工龋模型50例,随机分为5组：活性玻璃组、双黄连组、木糖醇组、NaF组、去离子水组。在体外进行pH循环后,测量各组乳牙的表面显微硬度,并结合偏光显微镜对乳牙的釉质龋损进行形态学观察。结果 活性玻璃组能显著提高乳牙早期釉质龋再矿化后的表面显微硬度（P<0.05）,但其提高的程度不如NaF组（P<0.05）,双黄连组、木糖醇组和去离子水组未能提高再矿化后的显微硬度（P<0.05）。偏光显微镜下,活性玻璃组与NaF组再矿化后乳牙表层釉质的脱矿深度明显变浅。结论 生物活性玻璃儿童牙膏能有效促进乳牙早期釉质龋再矿化,但其再矿化能力小于含氟牙膏,双黄连儿童牙膏和木糖醇儿童牙膏在本次实验中未能体现出再矿化能力。     

电阻抗仪评价含氟牙膏抑制早期根面龋的效果

目的:在体外含氟牙膏抑制早期根面龋的模型中评价电阻抗仪(ECM)反映早期根面龋损矿物质含量变化的效果.方法:将根面组织块开窗后分为2组:1.45 g/L含氟牙膏组和不含氟牙膏组,进行脱矿和再矿化循环.原子吸收光谱测定酸性缓冲液中的钙含量,电阻抗仪测量开窗区脱矿前后和再矿化前后的电阻值,激光扫描共聚焦显微镜(CLSM)分析再矿化后开窗区矿物质含量的变化.结果:脱矿后1.45 g/L含氟牙膏组的△LgECM和钙释出率低于不含氟牙膏组(P<0.01);ECM测量值与钙释出率具有较好的相关性(r>0.80).再矿化后1.45 g/L含氟牙膏组△LgECM高于不含氟牙膏组(P<0.05);CLSM分析发现1.45 g/L含氟牙膏组平均荧光量和总荧光量变化高于不含氟牙膏组(P<0.01);ECM测量值与CLSM结果具有较好的相关性(r≥0.70).结论:电阻抗仪能够客观地反映早期根面龋损矿物质含量的变化.氟浓度为1.45 g/L的牙膏与不含氟牙膏比较,具有明显地抑制早期根面龋的作用.     

干燥方法对定量光导荧光系统分析早期脱矿病损的影响

目的研究不同的干燥方法对定量光导荧光系统(guantitative light-induced fluorescence,QLF)分析病损脱矿程度的影响,探讨最适合QLF临床检查使用的干燥方法.方法选择新鲜拔除的人无龋前磨牙8个,颊面用指甲油封闭留窗口大约3mm×3mm,置于脱矿液中,37℃摇床中7d形成脱矿病损.标本分别采用三种不同的干燥方法放置于空气中使之自然干燥、压缩空气干燥30s和棉卷干燥30s,然后进行QLF检查并采用盲法分析病损脱矿的严重程度.设置△Q(荧光损失量)值变化5%为病损入口,得出的数据导入SPSS 11.5软件进行统计分析.结果釉质脱矿病损随着干燥程度的增加,在QLF荧光图像中均表现为脱矿严重程度的增加.病损放置自然干燥564.386(±87.542)s后,QLF能够检测到最大荧光损失,压缩空气干燥30s和棉卷干燥30s后,能检测最大荧光损失的时间分别为39.250(±7.778)s和139.375(±13.212)s.压缩空气吹干30s后,QLF图像中病损表现出明显的荧光损失,与其他两种干燥方法有统计学差异(P＝0.000).结论压缩空气干燥30s后,病损表现的荧光损失可以用来反映该病损的最大荧光损失值.临床使用压缩空气对早期病损吹干30s是达到可靠干燥效果的最快速而实用的方法.     

几种牙膏对早期釉质龋再矿化效果的体外研究

目的比较几种不同成分牙膏促进脱矿釉质再矿化的作用。方法选择新鲜拔除的牛下颌切牙制备成釉质块,形成早期人工龋。随机分为5组,各组依次为精氨酸牙膏组、氟离子浓度为0．11％牙膏组、酪磷酸蛋白牙膏组、氟化钠组（阳性对照组）、去离子水组（阴性对照组）。分别进行pH循环后,试验样本依次用显微硬度仪、偏光显微镜、激光共聚焦镜对再矿化程度进行检测。运用SPSS17．0软件,对检测结果进行单因素方差分析及配对t检验分析。结果显微硬度检测结果显示：精氨酸牙膏组、氟化钠组及酪磷酸蛋白牙膏组比0．11％含氟牙膏组的显微硬度恢复的百分比高（P〈0．05）。偏振光显微镜检测结果显示：酪磷酸蛋白牙膏组脱矿深度恢复的百分比高于0．11％含氟牙膏组,而较精氨酸牙膏组、氟化钠组低。激光共聚焦显微镜检测结果显示：酪磷酸蛋白牙膏组与0．11％含氟牙膏组荧光渗透减少量较精氨酸牙膏组及氟化钠组少。结论在本实验条件下,精氨酸牙膏、酪磷酸蛋白牙膏都能一定程度的促进早期釉质龋的再矿化作用,其中以精氨酸牙膏作用最强。     

定量光激发荧光技术检测乳磨牙窝沟封闭效果的临床研究

目的应用定量光激发荧光技术(quantitative light-induced fluorescence,QLF),评价树脂EMBRACE WetBond及玻璃离子GC FujiⅦ在隔湿条件有限的情况下对幼儿窝沟封闭半年的效果。方法选取符合纳入标准的成都市3～5岁114名幼儿,随机分为两组。采用树脂EMBRACE WetBond及玻璃离子GC FujiⅦ2种材料对幼儿乳磨牙牙合面窝沟封闭。所有检查者拍摄封闭前、封闭后、3个月和6个月的QLF照片,对绿色荧光和红色荧光分别进行分析。结果 105名儿童完成了6个月的临床试验,共计封闭牙齿201颗。两组儿童封闭牙齿绿色荧光总荧光损失量(△Q)封闭后、3个月及6个月的差异均有统计学意义(P<0.05),两组儿童封闭牙齿红色荧光总量(R)除3个月与6个月的差异无显著性意义外(P=0.191),其余各次差异均有显著性意义(P<0.01)。结论 QLF能够有效地评价乳磨牙窝沟封闭效果,可作为预防龋齿的手段之一。     

In vitro quantification of white spot enamel lesions adjacent to fixed orthodontic appliances using quantitative light‐induced fluorescence and DIAGNOdent

The aims of this in vitro study were 2‐fold: 1) to evaluate two fluorescence methods (DIAGNOdent and QLF (quantitative light‐induced fluorescence)) for quantification of white spot lesions adjacent to fixed orthodontic appliances; and 2) to determine the inter‐observer agreement of the DIAGNOdent and QLF methods for quantification of incipient enamel lesions adjacent to fixed orthodontic appliances. Forty‐one premolar teeth with visually sound smooth surfaces or visually white spot enamel lesions were included in the study. Orthodontic brackets were fixed adjacent to the lesions, thus simulating the position of fixed appliances during orthodontic treatment. All teeth were measured using both the DIAGNOdent and QLF methods. Of the 41 teeth, 20 smooth surfaces were randomly selected and analyzed by 4 operators using both DIAGNOdent and QLF. The teeth were sectioned into 300‐μm‐thick slices using a water‐cooled diamond saw and the slices manually ground to 80–100?μm thickness. Histopathology and transverse microradiography were performed to provide the gold standards for verification of lesion depth and mineral loss, respectively. The Spearman rank correlation coefficients between lesion depth determined by histopathology and the DIAGNOdent and QLF were 0.76 and 0.82, respectively, whereas the Pearson correlation coefficients between mineral loss and the two methods were 0.64 and 0.84, respectively. Inter‐observer agreement was found to be 0.80 and 0.93 for DIAGNOdent and QLF, respectively. In conclusion, QLF may be a suitable method for quantifying incipient carious lesions adjacent to fixed orthodontic appliances.     

Detection of in vitro demineralization adjacent to restorations using quantitative light induced fluorescence (QLF).

AIM: Quantitative light-induced fluorescence (QLF) is a technique for the detection, quantification, and longitudinal monitoring of early carious lesions. The technique is non-destructive and can be used in vivo. Using the natural fluorescence of teeth, and the loss of such fluorescence in demineralized enamel, QLF is a repeatable and valid optical caries monitor. Previously used in smooth and occlusal surfaces, the purpose of this pilot study was to determine if QLF could detect, and longitudinally monitor, demineralization adjacent to a range of restorative materials. METHODS: Fifteen previously extracted lower third molars were selected based upon the lack of any visible demineralization. A single burr hole was placed on the buccal surface and the cavity restored with amalgam, composite, compomer, glass ionomer or a temporary filling material. The buccal surface was then coated in an acid resistant nail varnish leaving an exposed area around the restoration and also a similar sized control region. The teeth had QLF images taken at baseline and were then subjected to a demineralizing buffer, further QLF images were subsequently taken at 72 and 144 h. Transverse microradiography was used to confirm the presence of early, subsurface lesions at the completion of the cycle (144 h). QLF images were analyzed by a single blinded examiner and values for change in radiance fluorescence were computed. These values were recorded as loss of radiance fluorescence loss integrated over area of lesion and expressed as DeltaQ. RESULTS: The appearance of each material under QLF and the change in fluorescence is described. Amalgam, glass ionomer and the temporary material all exhibited reduced fluorescence, while composite and compomer showed increased fluorescence, when compared with surrounding enamel. There was no change in fluorescence of the materials when subjected to experimental demineralizing conditions. Readings at 72 and 144 h demonstrated demineralization adjacent to the restorations and at the exposed control. Significant differences were detected between baseline, 72 and 144 h using ANOVA on all restorations with the exception of compomer where significance was noted between baseline and 144 h, p>0.05. CONCLUSIONS: This pilot study has demonstrated the ability for QLF to detect and monitor secondary caries. Analysis techniques should be based upon the subtraction of baseline DeltaQ scores from subsequent images. Further research is required to assess the ability of QLF to detect secondary lesions in vivo.     

In vitro quantification of white spot enamel lesions adjacent to fixed orthodontic appliances using quantitative light-induced fluorescence and DIAGNOdent

The aims of this in vitro study were 2-fold: 1) to evaluate two fluorescence methods (DIAGNOdent and QLF (quantitative light-induced fluorescence)) for quantification of white spot lesions adjacent to fixed orthodontic appliances; and 2) to determine the inter-observer agreement of the DIAGNOdent and QLF methods for quantification of incipient enamel lesions adjacent to fixed orthodontic appliances. Forty-one premolar teeth with visually sound smooth surfaces or visually white spot enamel lesions were included in the study. Orthodontic brackets were fixed adjacent to the lesions, thus simulating the position of fixed appliances during orthodontic treatment. All teeth were measured using both the DIAGNOdent and QLF methods. Of the 41 teeth, 20 smooth surfaces were randomly selected and analyzed by 4 operators using both DIAGNOdent and QLF. The teeth were sectioned into 300-microm-thick slices using a water-cooled diamond saw and the slices manually ground to 80-100 microm thickness. Histopathology and transverse microradiography were performed to provide the gold standards for verification of lesion depth and mineral loss, respectively. The Spearman rank correlation coefficients between lesion depth determined by histopathology and the DIAGNOdent and QLF were 0.76 and 0.82, respectively, whereas the Pearson correlation coefficients between mineral loss and the two methods were 0.64 and 0.84, respectively. Inter-observer agreement was found to be 0.80 and 0.93 for DIAGNOdent and QLF, respectively. In conclusion, QLF may be a suitable method for quantifying incipient carious lesions adjacent to fixed orthodontic appliances.     

Quantitative light-induced fluorescence (QLF)--a literature review

This paper on quantitative light-induced fluorescence (QLF) covers the main developments, physical principles, and current application areas of this noninvasive optical method for caries detection. Until now, QLF has mainly been used to detect and monitor initial carious lesions on smooth surfaces, whereas few studies have tried to assess its performance on occlusal pits and fissures. Since it is technically difficult to image proximal lesions, the use of QLF for detecting proximol lesions does not seem very promising from today's point of view. There can be no doubt that the method's great potential lies in the longitudinal observation of in vitro, in situ and in vivo demineralization and remineralization processes.     

Comparative study to quantify demineralized enamel in deciduous and permanent teeth using laser- and light-induced fluorescence techniques.

Caries is a disease that affects both deciduous and permanent dentitions. Caries progresses more rapidly in deciduous enamel than in permanent enamel. Therefore, new caries diagnostic methods need to be tested on the deciduous teeth as well. Quantitative laser-induced fluorescence (QLF I) as well as the quantitative light-induced fluorescence (QLF II) seem promising for the quantification of mineral loss from dental caries but have only been tested on the permanent dentition. The objective of this study was to determine and compare the ability of QLF I and QLF II to quantify mineral loss from carious lesions in both deciduous and permanent teeth. Thirty sound deciduous and 30 sound permanent teeth were cleaned and divided into three groups each containing 10 deciduous and 10 permanent teeth. Windows on the buccal or labial enamel surfaces were demineralized for 48, 72, or 96 h. Images of demineralized enamel were captured using QLF I and QLF II. The images were analyzed to determine the mean change in fluorescence radiance (Delta F, %). The teeth were then sectioned for assessment of lesion depth (microm) and integrated mineral loss (IML, vol% x microm) using transverse microradiography (TMR), as the 'gold standard' for lesion analysis. The results indicated a good correlation for Delta F between QLF I and QLF II in both deciduous (r = 0.96) and permanent teeth (r = 0.98). There was a good correlation between Delta F and TMR (lesion depth and IML) in deciduous teeth (r = 0.76 and 0.84 with QLF I, r = 0.81 and 0.88 with QLF II). In permanent teeth, the correlation between Delta F and TMR (lesion depth and IML) was lower than in deciduous teeth (r = 0.07 and 0.53 with QLF I, r = 0.15 and 0.62 with QLF II). From these results it can be concluded that either QLF method is capable of quantifying mineral loss in early carious lesions in deciduous teeth. Moreover, under the conditions of this study, the use of either QLF method to quantify mineral loss in early carious lesions in deciduous teeth is slightly more accurate than in permanent teeth.     

Detection of initial caries lesions on smooth surfaces by quantitative light-induced fluorescence and visual examination: an in vivo comparison

The aim of this clinical study was to compare the outcome of quantitative laser/light-induced fluorescence (QLF) and visual inspection (VI) for the detection of initial caries lesions on all maxillary and mandibular smooth surfaces in caries-risk adolescents. The subjects were 34 students, mean age 15 yr. A total of 879 buccal and 882 lingual surfaces were air-dried and visually examined at a magnification of x3.5. Fluorescence images of each smooth surface were captured with QLF\clin equipment, and QLF software 2.00 was used to display, store, and analyse the images. Fluorescence loss (deltaF; %) and area of the lesion (A; mm2), and fluorescence loss integrated over the lesion area (deltaQ; deltaF x A; % x mm2), were determined. The presence or absence of initial caries lesions was scored using both VI and QLF. A total of 87.2% of all smooth surfaces were scored as sound or initially carious when assessed by VI + QLF in combination: 4.9% were detected by VI alone and 7.9% by QLF alone. The parameters DeltaF, A, and DeltaQ differed significantly between lesions registered with VI + QLF and QLF alone. It was concluded that (i) QLF seems to be a sensitive method that is suitable for the detection of visually undetected initial caries lesions; and (ii) that the clinical use of QLF is limited by several confounding factors in caries-risk adolescents.     

The effect of dentine on fluorescence measurements of enamel lesions in vitro

This study aimed to determine the contribution of the underlying dentine and the enamel-dentine junction to measurements of mineral loss from enamel recorded using quantitative light fluorescence (QLF). Sixteen square blocks (5 x 5 mm) were cut from the labial surfaces of extracted bovine incisor teeth. A dental drill was used to remove dentine and the enamel-dentine junction from half of each specimen. All specimens were embedded in epoxy resin and ground to produce a smooth, flat enamel surface. Half of the enamel surface of the block, perpendicular to where the dentine had been removed, was demineralised for 72 h prior to undertaking QLF measurements from the enamel surface to compare fluorescence loss from different areas of the block. QLF readings taken from lesions with no underlying dentine or enamel-dentine junction were very similar to readings from lesions with underlying dentine. A comparison of the two data sets demonstrated a linear relationship with a gradient of 0.95 and a y intercept of -1.24 (r(2) = 0.936). From these data, the underlying dentine and enamel-dentine junction did not influence mineral loss in enamel measured using QLF.     

Detection of in vitro demineralization of primary teeth using quantitative light-induced fluorescence (QLF)

Summary. Introduction. With the advent of remineralizing therapies and the new, conservative approach to restoration placement, interest in detecting and monitoring subclinical, precavitated lesions has increased. The increased understanding of clinicians about the processes of primary and secondary prevention and the detection of lesions to which these therapies may be applied, is one of the current goals in caries management. Quantitative light‐induced fluorescence (QLF) is a new method for the detection of very early caries. Objectives. To determine the ability of QLF to detect and longitudinally monitor in vitro enamel demineralization. To present the device to the paediatric community and present future in vivo uses of the device. Design. An in vitro study with combined in vivo pilot. Sample and methods. Twelve previously extracted, caries free, primary molars were selected and prepared. Two teeth were randomly selected as controls. Teeth were prepared by gentle pumicing and coating in an acid‐resistant nail‐varnish, except for an exposed window on the buccal surface. QLF baseline images were taken and the teeth then exposed to a demineralizing solution. Teeth were removed at regular intervals (24, 48, 72, 96, 120, and 144 h), air‐dried and QLF images taken. QLF images were analysed by a single, blinded examiner (to control, to length of exposure). Mineral loss, as measured by ΔQ, was recorded. Results. Demineralization was noted in all experimental teeth by 48 h, and within 24 h in six teeth. The QLF successfully monitored the increase in mineral loss over time (P < 0·05). The detected lesions were not visible clinically until 144 h and then in only the most severe lesions. No demineralization was detected by QLF in control teeth. The device was user‐ and patient‐friendly in vivo, detecting subclinical lesions. Conclusion. Detection of very early mineral loss and subsequent monitoring of this loss is possible in primary teeth using QLF. The device is well suited to use in paediatric dentistry and offers applications for both clinicians and researchers. The determination of the status of carious lesions (active/inactive) will be possible with readings taken at recall appointments.     

Quantitative light-induced fluorescence (QLF)--a potential method for the dental practitioner.

The quantitative light-induced fluorescence (QLF) method is based on the natural fluorescence of teeth. Currently, the method is predominantly used in vitro and in clinical studies for early detection of carious lesions and for monitoring of de- and remineralization of white spots by quantifying the mineral loss and the size of smooth surface lesions. The objective of this paper was to demonstrate the potential of QLF for application in routine dental care. Experience with QLF was reported by selected cases, which enlightened the advantages of the method for caries detection and for evaluation of preventive interventions in caries-prone patients in daily practice.     

Laser-induced fluorescence from sound and carious tooth substance: spectroscopic studies

Fluorescence spectra of dentine and enamel illuminated with laser light of wavelengths of 337, 488, 515 and 633 nm respectively were recorded. The fluorescence obtained by illumination with UV laser light at 337 nm had a peak at about 400 nm in dentine as well as enamel. Compared to intact enamel the fluorescence from enamel with initial carious lesions was of lower intensity and had a slight red shift. No fluorescence within the visible range was obtained by illumination with a low power He-Ne laser at 633 nm. Illumination at 488 nm produced fluorescence with a peak at about 540 nm in dentine as well as enamel. The difference in the intensity of fluorescence between sound and carious enamel was generally greater at this wavelength than at any of the others tried, and the red shift from the carious enamel was also more pronounced. Illumination at 515 nm produced fluorescence of similar wavelengths but with much less difference between intact and carious enamel. It was concluded that illumination at 488 nm was the most suitable wavelength of those investigated for the detection of initial carious lesions by the fluorescence technique.