What Are Teeth Made Of?
A Complete Guide to Natural Teeth, Dental Materials and Tooth Replacements
It is one of those questions that sounds simple on the surface but leads somewhere surprisingly detailed once you start pulling at the thread. What are teeth made of? Most people know enamel is involved somewhere, but beyond that, the structure of a tooth — and the science behind what replaces or restores it — is something very few people outside dentistry ever get a proper explanation of.
Understanding what your teeth are made of is genuinely useful. It explains why certain foods and habits damage them, why different dental treatments are needed in different situations, what the materials used in restorations are actually doing, and why natural tooth structure, once lost, is worth protecting so carefully.
At Lateral Dental Clinic in Sheffield, led by Dr Matthew Stephens GDC No. 263989 and Dr Anupa Stephens GDC No. 264031, we believe that informed patients make better decisions about their oral health. This is the most complete guide you will find to what teeth are made of — covering natural tooth anatomy, the four different types of teeth, what happens inside the tooth when things go wrong, and the full range of materials used in modern dental restorations.
The Basic Answer: What Are Teeth Made Of?
A natural tooth is not made of a single material. It is a layered, living structure composed of four distinct tissues, each with a different composition, function and hardness:
- Enamel
- Dentine
- Pulp
- Cementum
Each layer plays a specific role, and understanding each one helps explain why teeth behave the way they do under pressure, temperature, acid and mechanical stress.
Enamel: The Hardest Substance in the Human Body
Enamel is the outermost layer of the tooth crown — the part you see above the gum line. It is the hardest biological material the human body produces, harder than bone, and it exists for one reason: to protect the softer tissues underneath from the enormous forces generated during biting and chewing.
What is enamel made of? Enamel is approximately 96 percent inorganic mineral, primarily hydroxyapatite — a crystalline calcium phosphate mineral arranged in tightly packed rods called enamel prisms. These prisms run from the enamel-dentine junction outward to the tooth surface and are oriented in specific directions that maximise resistance to fracture. The remaining four percent of enamel is water and organic protein.
This mineral density is what gives enamel its translucent, glass-like appearance. The natural colour of a tooth is actually mostly determined by the dentine beneath — enamel is semi-transparent, which is why thinner enamel at the edges of the front teeth often looks slightly more translucent or grey, while the thicker enamel over the body of the tooth appears more opaque and white.
The critical limitation of enamel: Despite being extraordinarily hard, enamel is brittle. It can crack under heavy impact, and — crucially — it cannot repair itself. Enamel contains no living cells. Once enamel is lost to acid erosion, decay or physical wear, the body cannot regenerate it. This irreversibility is one of the most important facts in all of dentistry, and it is the reason why protecting enamel is a priority in every aspect of dental care.
Acids are enamel’s primary enemy. Every time you consume something acidic — fizzy drinks, citrus fruits, vinegar-based foods — the pH in the mouth drops and enamel begins to demineralise. Saliva remineralises enamel between acid exposures, but frequent acid attacks prevent adequate recovery. Over time, this erodes the enamel surface, reducing tooth height, increasing sensitivity and permanently altering the appearance of the teeth.
Bacteria in dental plaque produce lactic acid as a byproduct of metabolising sugars, and it is this localised acid production that drives tooth decay. When decay progresses through the enamel and into the dentine beneath, a restoration — such as a filling — is needed to stop the progression.
Dentine: The Bulk of the Tooth
Beneath the enamel sits dentine, which makes up the largest proportion of the tooth structure. Dentine is less mineralised than enamel — approximately 70 percent hydroxyapatite, with the remaining 30 percent being water and organic material, primarily collagen. This lower mineral content makes dentine softer than enamel, and significantly more elastic, which is important: the slight flexibility of dentine provides a cushioning effect that prevents the more brittle enamel above it from shattering under occlusal load.
What makes dentine unique is that it is a living tissue. Throughout dentine runs a network of microscopic channels called dentinal tubules, which extend from the pulp at the centre of the tooth outward to the enamel-dentine junction. Each tubule contains the process of an odontoblast — a specialised cell that sits at the pulp-dentine border and is responsible for forming dentine throughout life.
This living connection between dentine and the pulp explains two important clinical phenomena:
Dentine sensitivity: When the dentinal tubules are exposed — through enamel loss, gum recession or tooth wear — external stimuli such as cold, heat, sweet foods and air contact can trigger fluid movement within the tubules. This fluid movement stimulates the nerve endings associated with the odontoblast processes, producing the sharp, short sensitivity that dentine hypersensitivity patients experience.
Secondary dentine formation: In response to decay, wear, or restorative procedures, the odontoblasts produce additional dentine — called secondary or reactionary dentine — as a protective response. This gradually reduces the size of the pulp chamber and increases the distance between the outer tooth surface and the nerve, which is part of how teeth adapt to ongoing challenges over a lifetime.
Dental Pulp: The Living Heart of the Tooth
The pulp is the soft tissue at the centre of the tooth. It occupies the pulp chamber in the crown and extends down through the root canals to the apex of each root. It is made up of:
- Connective tissue
- Blood vessels (arterioles and venules that supply nutrients and oxygen)
- Nerve fibres (both sensory and sympathetic)
- Lymphatic vessels
- Odontoblasts lining the pulp-dentine border
- Fibroblasts and immune cells
The pulp serves several functions: it nourishes the dentine throughout the tooth’s life, it provides sensory feedback (pain, pressure and temperature), it produces secondary dentine in response to injury, and it mounts an immune response when bacteria begin to approach the pulp space through advancing decay.
When decay or a crack reaches the pulp, the resulting infection and inflammation cause the severe, spontaneous toothache that most people associate with needing a dentist urgently. Once the pulp becomes irreversibly inflamed or infected, root canal treatment is typically needed to remove the infected pulp tissue, clean and shape the root canal system, and seal it to prevent re-infection. Following root canal treatment, the tooth retains its function but is no longer vital — it no longer has a blood or nerve supply, which is why teeth that have had root canal treatment can sometimes become more brittle over time and benefit from protection with a dental crown.
Cementum: The Anchor Layer
Cementum is a calcified tissue that covers the root surface of the tooth, from the cemento-enamel junction (where the crown meets the root) down to the root apex. It is similar in composition to bone — approximately 65 percent hydroxyapatite with the remaining 35 percent being organic material and water — though it is avascular (contains no blood vessels) and generally thinner than bone.
The primary function of cementum is to anchor the tooth within the jawbone via the periodontal ligament. Thousands of collagen fibres — Sharpey’s fibres — embed into the cementum on one side and into the alveolar bone on the other, suspending the tooth in its socket and allowing a small degree of physiological movement during chewing. This shock-absorbing suspension is why natural teeth feel different to bite on compared to dental implants, which integrate directly with bone and lack this ligament.
Cementum can regenerate to a limited degree, which is clinically important in the treatment of gum disease. However, when cementum and the underlying dentine are exposed through gum recession, the root surface becomes vulnerable to both sensitivity and decay — root caries being a particular concern in older patients.
The Periodontium: The Support System
While not part of the tooth itself, the periodontium — comprising the gum tissue, periodontal ligament, cementum and alveolar bone — is the support structure that determines whether a tooth can remain in function. Gum disease is the most common cause of tooth loss in adults in the UK, and its progression through the periodontium is what makes it so destructive. Understanding that what are teeth made of includes not just the tooth itself but also its attachment apparatus helps explain why gum health is taken so seriously in modern dental practice.
The Four Types of Teeth: Structure and Function
Now that we understand the fundamental materials all teeth share, it is worth examining the four different types of permanent teeth, because their shape reflects their specific function.
Incisors
There are eight incisors in the adult dentition — four upper and four lower — and they are the flat, chisel-shaped teeth at the front of the mouth. Their primary function is cutting and incising food. They have a single root, a relatively thin enamel layer and a wide, flat crown. The central incisors are the largest and most visible, making them the focus of most cosmetic dental work.
Because incisors are thin, they are particularly susceptible to enamel erosion and chipping. They also show translucency at the edges when enamel thins, which is one of the characteristic signs of acid erosion.
Canines
The four canines — one in each corner of the mouth — are the pointed teeth that sit between the incisors and the premolars. They are the longest teeth in the mouth when measured root to tip, have a single root, and are designed for tearing and gripping food. They also play a critical role in guiding the bite: in most people, canine guidance protects the back teeth from excessive lateral forces during chewing.
Because of their prominent position and length, canines are important structural teeth. Their loss or significant wear has consequences beyond aesthetics.
Premolars
Premolars — also called bicuspids — sit between the canines and the molars. Adults have eight premolars in total, and they serve a transitional function: beginning the crushing and grinding of food before it reaches the molars. They typically have one or two roots and a more complex crown shape with cusps designed for grinding.
Molars
The molars are the large, broad teeth at the back of the mouth, with multiple cusps designed for heavy grinding. Adults typically have twelve molars in total, including the four wisdom teeth (third molars). First and second molars have two to three roots depending on whether they are upper or lower jaw teeth, and their root systems are the most complex of all tooth types.
The molars bear the greatest occlusal load in the mouth, which is why they are the teeth most likely to fracture under heavy biting forces or grinding (bruxism) and why dental crowns are frequently used to restore and protect molar teeth that have been significantly weakened by decay or previous restorations.
What About Children's Teeth? Primary Dentition
Before the permanent dentition, children have 20 primary (baby) teeth — also called deciduous teeth. Primary teeth are made of the same four tissues as permanent teeth — enamel, dentine, pulp and cementum — but with some important structural differences:
- The enamel layer is thinner
- The dentine is less mineralised
- The pulp chamber is proportionally larger relative to the overall tooth size
- The roots are designed to resorb over time, allowing the permanent teeth to erupt
These differences mean primary teeth are more susceptible to decay than permanent teeth, and that decay progresses more quickly through the thinner enamel and dentine. Healthy primary teeth matter both for function and nutrition during childhood and as space maintainers that guide the permanent teeth into their correct positions.
What Are Dental Restorations Made Of?
When natural tooth structure is damaged or lost, modern dentistry offers a range of materials that replicate or replace what was there. Understanding what are teeth made of when restored is just as important as understanding natural tooth composition.
Composite Resin: Tooth-Coloured Fillings and Bonding
Composite resin is a tooth-coloured material consisting of a resin matrix (usually bisphenol A-glycidyl methacrylate, known as Bis-GMA) reinforced with inorganic filler particles — typically glass, quartz or silica. The filler particles give the material its strength and wear resistance, while the resin matrix provides the binding medium and the ability to be shaped and polished.
Composite resin is used for:
- White fillings to restore decay or damage
- Composite bonding to improve the shape, length or colour of teeth
- Composite veneers as an alternative to porcelain
Composite bonds to tooth structure through a combination of micromechanical retention (the resin penetrating etched enamel and dentine) and adhesive chemistry. It is placed in layers, each cured with a high-intensity blue light that triggers polymerisation. Modern composites are available in a wide range of shades and opacities that allow skilled clinicians to match natural tooth appearance very closely.
Composite veneers specifically are thin layers of composite resin applied directly to the front surface of a tooth to improve its shape, colour or proportion. They are sculpted freehand or placed using a template and polished to a natural finish. They can be completed in a single appointment, require minimal tooth preparation and are reversible — making them one of the most conservative cosmetic options available. The trade-off compared to porcelain is longevity: composite veneers typically last five to seven years before they need polishing, repair or replacement, whereas porcelain veneers can last ten to fifteen years or more.
Porcelain and Ceramic: Veneers and Crowns
Dental porcelain is a glass-ceramic material valued for its exceptional ability to mimic the optical properties of natural tooth enamel. Like natural enamel, porcelain is semi-translucent, reflects and transmits light in a way that looks lifelike, and can be characterised with stains and surface texture to produce extraordinarily realistic results.
What are porcelain veneers made of? Porcelain veneers are thin shells of dental ceramic — typically between 0.3 and 0.7mm thick — fabricated in a dental laboratory from a precise impression or digital scan of the prepared tooth. Modern veneer ceramics include feldspathic porcelain (the most aesthetically nuanced, typically used for anterior restorations), leucite-reinforced glass-ceramic (such as IPS Empress) and lithium disilicate (such as IPS e.max), which offers a superior combination of strength and aesthetics and has become the material of choice for most veneer cases.
Porcelain veneers are bonded to the tooth surface using a dental adhesive resin cement, creating a strong and durable bond that is resistant to staining and wear. Unlike composite, porcelain cannot be repaired easily once chipped — chips typically require replacement of the veneer — but their resistance to staining and superior longevity make them the preferred choice for long-term smile transformations.
What are dental crowns made of? Dental crowns cover the entire visible crown of a tooth and are used when a tooth is too damaged, weakened or broken to be restored with a filling or veneer. Crown materials include:
- Full ceramic or zirconia crowns: The most common choice for modern all-ceramic restorations. Zirconia (zirconium dioxide) is exceptionally strong — stronger than traditional porcelain — and can now be produced with excellent translucency for anterior use. Layered zirconia crowns, where a monolithic zirconia core is overlaid with a more aesthetic feldspathic porcelain, combine strength with a high level of visual realism.
- Porcelain-fused-to-metal (PFM) crowns: An older technology in which a porcelain outer layer is bonded to a metal substructure. Durable but increasingly replaced by all-ceramic options, as the metal substructure can show as a dark line at the gum margin over time and the aesthetics are generally inferior to full ceramic.
- Gold and metal alloy crowns: Extremely durable and require the least tooth reduction of any crown material. Still used in some molar situations where aesthetics are less important and maximum longevity is the priority.
Dental Bridges: What Are They Made Of?
A dental bridge replaces one or more missing teeth by anchoring to the teeth on either side of the gap — the abutment teeth — with a false tooth (pontic) suspended between them. Bridges are fabricated in the same materials as crowns — most commonly full ceramic, zirconia or porcelain-fused-to-metal — and are permanently cemented in place.
Maryland bridges use a slightly different design: a metal or ceramic wing bonded to the back surface of adjacent teeth, rather than full crowns. This preserves more of the adjacent tooth structure, making it a more conservative option in suitable cases.
Dental Implants: Titanium and Ceramic
For patients with missing teeth, dental implants are the most anatomically similar replacement to a natural tooth root. The implant fixture itself is made of commercially pure titanium or a titanium alloy, chosen because titanium undergoes osseointegration — it bonds directly with living bone through a biological process that creates a stable, long-term foundation. The crown placed on top of the implant is typically made of the same ceramic materials used for conventional crowns, most commonly zirconia or porcelain-fused-to-zirconia.
Why Understanding Tooth Composition Matters for Your Dental Care
Knowing what are teeth made of is not just academic — it has direct practical implications:
- Acid and enamel: Understanding that enamel is irreversibly lost to acid erosion explains why the frequency of acid exposure matters more than the amount. Sipping a fizzy drink over an hour is far more damaging than drinking it quickly, because it sustains the pH drop in the mouth for longer.
- Dentine sensitivity: Knowing that sensitivity occurs because exposed dentinal tubules allow fluid movement in response to stimuli explains why sensitivity toothpastes work (they occlude the tubule openings) and why the problem may require professional treatment if it is severe or persistent.
- The case for crowns after root canal treatment: Understanding that root canal treated teeth lose their pulpal blood supply and can become more brittle over time explains why protecting them with a dental crown is often the clinically correct decision, particularly for molar teeth bearing heavy loads.
- Choosing between composite and porcelain: Understanding the composition and properties of both materials allows patients to make an informed choice between composite bonding and porcelain veneers based on their priorities — budget, longevity, reversibility and the degree of aesthetic improvement needed.
A Note on Nervous Patients
One thing worth noting in any discussion of dental treatment is that anxiety is one of the most common reasons people avoid the care their teeth need. At Lateral Dental Clinic, we offer conscious sedation for patients who find dental treatment difficult. Whether you need a routine restoration, root canal treatment, a crown or cosmetic work, sedation can make the experience entirely manageable. Dental anxiety should never stand between you and treatment that protects the tissues your teeth are made of.
The Bottom Line
So, what are teeth made of? At their core, natural teeth are a precisely engineered layered structure: a mineralised enamel shell protecting a living dentine body, wrapped around a vascular and nervous pulp, anchored via cementum and the periodontal ligament into the jawbone. Each layer has a specific composition, a specific function and specific vulnerabilities — and understanding those vulnerabilities is the foundation of good preventive care.
When natural tooth structure needs restoring or replacing, modern dental materials — composite resin, dental ceramics, zirconia, titanium — replicate these properties with increasing sophistication. Whether through composite bonding, porcelain veneers, dental crowns, bridges or root canal treatment, the aim is always the same: to preserve or restore function and appearance using materials that work with the biology of the tooth rather than against it.
At Lateral Dental Clinic in Sheffield, Dr Matthew Stephens and Dr Anupa Stephens bring a depth of clinical knowledge and a patient-centred approach to every treatment decision. If you have questions about your teeth or want to understand your options, our general dentistry team is here to help.
Disclaimer
The information in this article is intended for general educational guidance only and does not constitute personalised dental or medical advice. For a full assessment of your dental health and treatment options, please book an appointment with a qualified dental professional.
Lateral Dental Clinic is a private dental practice in Sheffield, led by Dr Matthew Stephens GDC No. 263989 and Dr Anupa Stephens GDC No. 264031. We offer a full range of dental treatments including general dentistry, root canal treatment, dental crowns, dental bridges, porcelain veneers, composite bonding, dental sedation, Invisalign, teeth whitening and smile makeovers.
Questions our patients ask
Enamel is the hardest tissue in the human body, harder than bone. It is composed of approximately 96 percent hydroxyapatite mineral arranged in crystalline prism structures. Despite this hardness, enamel is brittle and irreversible: once it is lost to acid erosion, decay or wear, the body cannot produce new enamel. This is why protecting enamel through good oral hygiene, diet choices and regular dental check-ups is so clinically important.
No. Dentine and enamel are distinct tissues with different compositions and properties. Enamel is 96 percent mineral, contains no living cells and cannot regenerate. Dentine is approximately 70 percent mineral with a significant organic component, contains living cellular processes within its tubule network, and can produce additional secondary dentine in response to damage or decay. Dentine is softer and more elastic than enamel, which provides the cushioning that prevents enamel from fracturing under bite pressure.
Composite veneers are made of resin-based composite material — the same type used for white fillings — applied directly to the tooth surface and shaped and polished by the dentist in a single appointment. Porcelain veneers are thin ceramic shells fabricated in a dental laboratory and bonded to the prepared tooth surface. Porcelain offers superior stain resistance and typically greater longevity (ten to fifteen years versus five to seven for composite), while composite bonding is more cost-effective, completed in one visit and fully reversible.
Dental crowns are used when a tooth has lost so much of its original structure — through decay, fracture, large old restorations or following root canal treatment — that a filling or veneer cannot adequately restore it. A crown encases the entire visible portion of the tooth, redistributing occlusal forces across the full circumference and protecting what remains of the natural tooth structure underneath. Modern crowns are made from tooth-coloured zirconia or ceramic materials that are both strong and aesthetically natural.
A dental bridge is a fixed restoration that replaces a missing tooth by suspending a false tooth (pontic) between two crowns placed on the adjacent teeth. It is typically made from ceramic or porcelain-fused-to-metal and is permanently cemented in place. A dental implant, by contrast, replaces the tooth root itself using a titanium fixture that integrates with the jawbone, topped with a ceramic crown. Implants preserve the bone beneath the gap — which bridges do not — and do not require preparation of the adjacent teeth, making them the more conservative long-term solution where suitable.
