Shade selection Flashcards
Why is correct shade selection important in dentistry?
✅ It ensures superior aesthetics 👑
✅ Satisfies both dentist and patient 😊
✅ Requires understanding of colour science & perception 🎨👁️
✅ Leads to a pleasing, natural appearance 🌟
What are the consequences of poor shade selection? 😬
❌ Poor aesthetics 🫣
❌ Lack of translucency at incisal edges 🌫️
❌ Functional teeth but aesthetic failure 🚫
❌ May cause gingival inflammation, recession worsens 🩸🌱
What 3 variables are used to characterise tooth shade perception? 🔍
1️⃣ Hue 🎨 (Dominant colour)
2️⃣ Value ⚖️ (Lightness/darkness)
3️⃣ Chroma 🌈 (Colour intensity)
Define Hue, Value, and Chroma using the VITA Guide system 🗂️
🎨 Hue: Name of colour (e.g. A = red/yellow, B = yellow, C = grey, D = red-yellow-grey)
🌈 Chroma: Intensity/saturation of colour (represented by numbers in VITA Guide)
⚖️ Value: Lightness/darkness, measured independent of hue (affects enamel selection)
How do you read a shade like A3 in the VITA guide? 🅰️3️⃣
🅰️ = Hue (red/yellow)
3️⃣ = Chroma (intensity level)
❓ Q6: What is the difference between the traditional VITA Guide and VITA 3D Master? 📘📗
📘 Traditional: Hue + Chroma
📗 VITA 3D Master: Focuses on Value/lightness first ➡️ then Chroma ➡️ then Hue
How is lightness determined using the shade guide? 💡
📏 Hold guide 20–30 cm from patient’s tooth
👁️ Arm bent, assess under daylight
🔢 Select lightness level: 0-5
🎯 Then choose Chroma & Hue
What are limitations of the shade guide system? 🚧
⚠️ Shade guide colours vary by manufacturer 🏭
⚠️ Not universal across resin, porcelain, dentures 🦷
⚠️ Important to match lab’s shade guide for indirect restorations 🧪🧑🔬
What 3 factors influence shade selection? 🧠🔦👀
1️⃣ The Object (Tooth) 🦷
2️⃣ The Observer 👁️
3️⃣ The Illumination 💡🌞
How does light interact with a tooth surface? 🌈
🔁 Light can be reflected, absorbed, or transmitted
💎 Smooth surface = specular reflection (mirror-like)
🪨 Rough surface = diffuse, scattered reflection
🦷 Teeth have surface texture (mamelons, ridges), age-related translucency & blocks
What is the difference between light source and illuminant? 🔦☀️
💡 Light Source: Physical object emitting light (lamp, sun)
📊 Illuminant: Standardised light used in colour matching (defined spectral output)
Why is daylight the preferred light source? ☀️
🌞 Natural balance of blue + yellow light
📸 Best mimics environment in which tooth will be seen
📍 Position near window for natural daylight
What’s the “blue/gold dress” phenomenon in shade matching? 👗🧠
🧠 Perception of colour varies with assumed light source
👁️ Daylight = white/gold
💡 Artificial warm light = blue/black
👆Same applies to teeth under different lighting!
What visual limitations does the observer (dentist) face? 🙈
🌀 Image inversion
🌈 Chromatic/spherical aberrations
🕳️ Blind spot gaps
🌑 Low light = rod cells (black/white only)
🌞 Bright light = cone cells (full colour)
What are clinical considerations for shade selection? 🧑⚕️🪥
📆 Morning = best time (no eye fatigue)
📏 Eye-level matching: 61–183 cm away
🪞 Patient upright, teeth at operator’s eye level
👯♂️ Consult patient & assistant
🕛 Midday light optimal, else use daylight-mimicking artificial light
👚 Use drape to cover bright clothing
💄 Remove lipstick
🩺 Teeth must be clean, moist with saliva
🚫 Avoid shade selection after applying rubber dam
What clinical tips help with better shade matching? 💡📸🦷
📸 Take photographs with shade tabs
🪄 Use direct composite trial on tooth (no bonding)
🗺️ Draw a shade map for lab
🖼️ Adjust digital images:
🖤 Convert to black & white to assess value
🌈 Boost colour intensity to visualise chroma
📦 Provide digital clinical photos for complex cases
🎯 Take stump shade (underlying colour) for crowns
🧱 Helps block dark areas in trauma cases
What colour measuring instruments are available? 🧪📊
📏 Colorimeter
🌈 Spectrophotometer
🧬 Spectroshade hybrid devices
👉 These provide objective, accurate shade data
What determines the colour of an object? 🌈👀
The colour of an object is determined by:
🔦 Light Source (Illuminant) – what kind of light is shining on it
🪞 Surface Reflection – how much light is reflected off the object
🌫️ Absorption – which wavelengths of light are absorbed
💎 Transmission – how much light passes through the object
🧠 Perception – how our eyes and brain interpret that light
🧪 Colour = Combo of reflected + transmitted + absorbed light ➕ perception under specific lighting!
What are the key properties of teeth to consider when doing shade selection for restoration? 🦷🎨
🦷 Tooth properties to consider include:
1️⃣ Hue – dominant colour (A = red-yellow, B = yellow, etc.)
2️⃣ Value – how light or dark the tooth is
3️⃣ Chroma – intensity or saturation of colour
4️⃣ Translucency – especially near the incisal edge
5️⃣ Fluorescence – how tooth glows under UV light
6️⃣ Opalescence – bluish-white glow in light
7️⃣ Surface Texture – affects how light reflects (smooth vs rough)
8️⃣ Gloss – shine or dullness
9️⃣ Age-related changes – younger teeth are more translucent and lighter
🔟 Tooth Structure – enamel vs dentine (enamel = more translucent, dentine = more chromatic)
