Dental inlays and onlays are custom-made, indirect tooth restorations used to repair moderately damaged or decayed teeth. Unlike a simple filling applied directly to the cavity, inlays and onlays are fabricated outside the mouth and then bonded to the tooth. An inlay fits within the cusps (points) of a back tooth, restoring the chewing surface, whereas an onlay covers one or more cusps of the tooth. Both procedures preserve more natural tooth structure than a full crown, making them a conservative choice. They are durable and long-lasting restorations that require no special care beyond normal brushing, flossing, and routine dental checkups.
Dental inlays and onlays can be placed in two main ways: direct (same-day) or indirect (lab-made). In a direct inlay/onlay procedure, the restoration is crafted right in the dental office, often using CAD/CAM milling technology, and placed in a single visit. For example, some practices use in-office scanners and milling machines to design and mill a ceramic inlay on the spot, so the patient can leave with a permanent restoration that day.
In contrast, an indirect inlay/onlay requires two appointments. On the first visit, the tooth is numbed, the decay or old filling material is removed, and the tooth is prepared (shaped) for restoration. An impression or digital scan of the prepared tooth is then taken to create an exact model. A temporary filling is placed while the permanent inlay/onlay is custom-fabricated in a dental laboratory. At the second visit (usually 1–2 weeks later), the temporary is removed and the final restoration is carefully bonded or cemented into place. This two-visit method is common, though advances in technology (like CEREC or CADD/CAM systems) are making same-day ceramic inlays more available. To learn more about the effectiveness and benefits of dental inlays and onlays, you can explore this dental research article from the Journal of the American Dental Association.
Inlays and onlays can be made from various materials, each with advantages and trade-offs:
Porcelain/Ceramic: These tooth-colored materials are very popular for inlays/onlays because they can be closely matched to your natural tooth color and have a translucent, enamel-like appearance. Porcelain is strong, biocompatible, and highly stain-resistant. Modern bonded porcelain inlays are extremely durable; many Boston-area practices note lifespans of 10–30 years or more. For example, one clinician reports that ceramic inlays often last “a lifetime” and far outlast conventional fillings. The main downsides are cost and procedure complexity: porcelain inlays require lab fabrication (unless milled in-office) and typically cost more upfront than fillings. However, their longevity can make them cost-effective over time.
Composite Resin: Composite (white) inlays are also tooth-colored and are typically less expensive than porcelain. They are made from a durable plastic/glass mixture and are custom-processed outside the mouth. Composite inlays/onlays bond directly to the tooth and look similar to ordinary fillings. They are a good option for moderate restorations, especially where cost is a concern. However, composite restorations are generally less durable than porcelain; they tend to wear down or stain over time. Studies show composite fillings (and by extension composite inlays) often last only 5–10 years, compared to 15 years or more for porcelain inlays. In practice, a composite inlay might need to be replaced or repaired sooner than a porcelain one.
Gold Alloy: Gold inlays and onlays are the traditional “gold standard” for strength. A gold restoration is extremely durable and wears very similarly to natural tooth enamel. Gold inlays can last for decades and are very gentle on opposing teeth. The main drawback is aesthetics: the metallic color is conspicuous, so gold is mainly used on molars or in patients who prioritize longevity over appearance. Gold also requires a lab fabrication process and is often more expensive than tooth-colored options. Some practices still offer gold restorations for patients who need maximum durability.
(Another modern material is zirconia ceramic, used for one-day CAD/CAM crowns and inlays. Zirconia is very strong and tooth-colored, but for most patients, porcelain, composite, or gold cover all needed options.)
Getting an inlay or onlay typically involves the following steps:
Consultation & Tooth Preparation: The dentist examines the tooth (often with X-rays) to determine if an inlay/onlay is appropriate. The area is numbed with a local anesthetic to ensure comfort. The dentist then removes all decay and any old filling material, thoroughly cleans the tooth, and reshapes the cavity so the new restoration will fit perfectly.
Impression or Digital Scan: Once the tooth is prepared, the dentist takes an impression (mold) of the tooth, or uses a digital intraoral scanner to create a precise model. This model is sent to a dental lab, where the custom inlay or onlay is crafted from the chosen material (porcelain, composite resin, or gold). Alternatively, in offices with CAD/CAM technology, this step can be done with an in-house milling machine that carves the restoration from a ceramic block on the same day.
Temporary Restoration (if needed): If the final restoration will be made in a lab, the dentist places a temporary filling or restoration on the tooth to protect it while you wait. This ensures the tooth is sealed and comfortable between visits.
Final Placement: After about 1–2 weeks (or immediately, if same-day CAD/CAM was used), you return for the final fitting. The dentist removes the temporary restoration and tries in the new inlay/onlay. They carefully check the fit and your bite. If everything aligns properly, the dentist permanently bonds or cements the inlay/onlay to the tooth. Any minor adjustments are made for comfort, and the restoration is polished so it looks and feels smooth. Because your tooth was anesthetized, you’ll feel minimal discomfort during placement.
Throughout the procedure, advanced bonding agents and curing lights ensure the restoration is securely attached. Modern techniques allow for a “superior fit” so the inlay/onlay acts like a natural part of your tooth. Most patients only experience mild sensitivity afterward, which typically resolves within a day.
Conservative Treatment: Inlays and onlays require much less drilling and tooth removal than crowns. By preserving more of your natural tooth structure, these restorations keep the tooth stronger and healthier in the long run.
Strength and Durability: Bonded inlays and onlays actually reinforce the remaining tooth. They can restore up to ~75% of the tooth’s original strength. For example, a large molar with an inlay/onlay can be stronger than it was with a big metal filling. High-quality porcelain inlays are very long-lasting – many last 10–30 years or more with proper care. Some practices report inlays/outlays surviving “a lifetime” under good maintenance.
Aesthetics: Porcelain and composite inlays/onlays blend seamlessly with natural teeth. They eliminate the silver-gray appearance of metal fillings. According to dental experts, porcelain restorations are stronger than older tooth-colored fillings and look excellent under most conditions. Because they match your tooth color, inlays and onlays are essentially undetectable in your mouth, making them ideal for visible areas.
Longevity and Cost-Effectiveness: Although inlays/onlays cost more upfront than standard fillings, their superior strength means they often need fewer replacements over time. Ceramic inlays, in particular, are extremely stain-resistant, maintaining their appearance for many years. By preventing further decay and avoiding repeated filling failures, inlays/onlays can save money in the long run despite higher initial cost.
Reduced Risk of Future Decay: Because these restorations are custom-fit, they create very tight, precise margins against the tooth. Porcelain inlays have been shown to have less bacterial leakage than composite fillings, lowering the chance of decay seeping in around the edges. Inlays and onlays also often promote healthier gums, since their smooth edges are easy to keep clean.
Mercury-Free Option: For patients concerned about metal, inlays/onlays offer a metal-free solution. Porcelain or composite inlays avoid the mercury content found in old amalgam fillings. Some dentists specializing in holistic dentistry prefer all-porcelain inlays to eliminate any potential mercury exposure.
Dental inlays and onlays are generally very safe, but as with any procedure there are a few potential complications to be aware of:
Sensitivity or Discomfort: Your mouth is numbed during the procedure, so you shouldn’t feel pain while the tooth is being prepared and the inlay/onlay placed. After the anesthesia wears off, it’s common to feel mild sensitivity or discomfort around the treated tooth for a day or two. This usually subsides on its own. Your dentist may recommend over-the-counter pain relievers if needed. If sensitivity or pain persists longer or is severe, be sure to contact your dentist.
Fit and Bite Issues: In rare cases, the new restoration might not fit perfectly or could feel “high” when biting. A poor fit can cause sore spots or allow bacteria to enter the margin, leading to decay. Reputable dentists will carefully check and adjust the inlay/onlay for a perfect fit. Always let your dentist know if the bite feels off after your inlay is placed.
Allergic Reaction: Although uncommon, some patients may have allergies to certain dental materials (usually metal alloys). If you are sensitive to metals, inform your dentist — they can use tooth-colored materials (ceramic or resin) to avoid this issue.
Material Wear or Damage: No restoration is indestructible. Extreme habits like chewing ice, biting hard objects, or heavy tooth grinding (bruxism) can crack or dislodge an inlay/onlay. If you grind your teeth, your dentist may suggest a night guard to protect your new restoration.
Other Rare Risks: Very rarely, complications like anesthetic reactions or gum/ soft-tissue irritation may occur, but these are no more common than with any other dental filling or crown procedure. Choosing an experienced dentist and following all post-op instructions greatly minimizes risks.
Overall, serious problems are unusual. Most patients find inlays/onlays to be completely safe with proper placement by a qualified dentist.
Cost is an important consideration. In Arlington (and the greater Boston area), inlays/onlays are more expensive than a standard filling but usually less than a full crown. For instance, one Boston-area dentist reports that a ceramic (porcelain) inlay/onlay typically runs about $900–$1,400 per tooth. (A large composite filling might cost around $300–$500 in comparison.) A full crown generally costs more, often in the range of $1,200–$1,600 or higher.
A local example is Greater Boston Dental (Watertown, MA), which lists bonded ceramic onlays at $900–$1,400 depending on size, while a silver or white plastic filling costs only $275–$375. These figures illustrate that high-quality inlays/onlays are a significant investment, but they also last much longer than cheap fillings, potentially making them cost-effective over time.
Insurance: Most dental insurance plans consider inlays/onlays as “major” restorative work. Many plans will cover a portion of the cost – on average about 50% – but coverage can vary widely. Coverage often depends on whether your plan’s fee schedule, the tooth involved, and material used. It’s best to consult with your insurance and dentist’s office; they can provide a pre-treatment estimate. If insurance isn’t generous, many Arlington dentists offer flexible financing, payment plans, or CareCredit options to help spread out the cost.
When discussing inlays/onlays with your dentist, be sure to ask for a detailed fee estimate and whether any discounts or financing plans are available. Ultimately, the improved durability and aesthetics of an inlay/onlay can justify the higher price compared to redoing fillings repeatedly.
After your inlay or onlay is placed, the good news is that care is just like caring for a natural tooth. With proper hygiene and habits, these restorations can last many years – often 10, 15, or even 30+ years. Here are key aftercare tips:
Oral Hygiene: Brush your teeth at least twice a day and floss daily, paying particular attention to the area around the new inlay/onlay. While the restoration itself won’t decay, the edges of the tooth can still be vulnerable to plaque buildup. Consistent brushing and flossing help prevent any new cavities from forming at the margins.
Avoid Hard Bites: Be gentle with the treated tooth while it heals. Avoid chewing on ice, hard candy, pens, or fingernails. Inlays and onlays are strong, but habits like biting very hard items or grinding can chip or loosen them. If you grind or clench at night (bruxism), consider wearing a custom night guard. This will protect the inlay/onlay (and your other teeth) from excessive force.
Dietary Care: For the first 24 hours after placement, stick to soft foods until any temporary numbness wears off. After that, you can resume your normal diet. In general, avoiding excessively sticky or hard foods can help preserve the restoration.
Regular Check-Ups: Keep up with your twice-yearly dental visits. At each cleaning, the dentist or hygienist will examine the inlay/onlay and the surrounding tooth. Any minor wear or issues can be caught early. They will also professionally clean areas you might miss at home, ensuring the restoration’s margins stay debris-free.
Watch for Changes: Pay attention to any new sensitivity or discomfort in that tooth. It’s normal to feel slight tenderness for a few days, but pain that lingers or worsens should be checked by your dentist. Also, if you feel a raised edge or small gap after a few weeks or months, make an appointment – it might need adjusting.
Following these guidelines, most patients enjoy trouble-free inlays/onlays for many years. Remember: good oral hygiene and responsible chewing habits are the biggest factors in the long-term success of your restoration.
What is the difference between a dental inlay and an onlay?
An inlay is a custom-made filling that fits within the cusps (points) of a tooth, replacing the damaged chewing surface inside the tooth. An onlay covers one or more cusps (the points) of the tooth, extending over a larger area. In simple terms: if the damage is limited to the center of the tooth between the cusps, an inlay is used; if a cusp needs repair, an onlay is placed. Both are made in a lab (or milled in-office) and then bonded to the tooth.
How long do inlays and onlays last?
With proper care, inlays and onlays are very durable. Porcelain (ceramic) inlays and onlays can last 10–30 years or more, often outlasting conventional fillings. Composite inlays generally last 5–10 years. Gold inlays can last several decades. Ultimately, longevity depends on material quality, how well you maintain them, and your biting habits. Many patients enjoy their inlays/onlays for 15+ years.
What materials are used for inlays and onlays?
Common materials include porcelain (ceramic), composite resin, and gold alloy. Porcelain is tooth-colored and stain-resistant. Composite resin is also white and more affordable. Gold is metallic but extremely strong and long-lasting. Your dentist will discuss the pros and cons (durability, cost, appearance) of each before deciding.
What does getting a dental inlay or onlay involve?
The dentist will numb the tooth and remove any decay. The tooth is then prepared and an impression or digital scan is taken. A temporary filling is placed while a custom inlay/onlay is made. In a second visit (1–2 weeks later), the final inlay/onlay is bonded in place. In offices with special CAD/CAM equipment, steps can be combined into a single appointment.
Are inlays and onlays painful?
The procedure is performed under local anesthesia, so you should not feel pain during treatment. Afterward, it’s common to feel mild sensitivity or soreness for a day or two, which typically goes away quickly. Over-the-counter pain relief can manage any discomfort. Most patients describe the process as no more painful than getting a crown or filling.
What are the benefits of dental inlays/onlays?
Inlays/onlays are very conservative – they preserve most of your natural tooth and require less drilling than crowns. They are also strong and long-lasting. Bonding an inlay/onlay can strengthen the tooth by up to ~75% compared to a large filling. Aesthetically, they look like natural teeth (especially porcelain/composite types). Overall, they provide a durable, exact-fit restoration for large cavities without covering the whole tooth.
What are the risks of getting an inlay/onlay?
Risks are minimal. Possible issues include temporary sensitivity, and if the fit isn’t perfect, some discomfort when chewing. Rarely, there can be an allergic reaction to a material or an issue with the numbness or anesthesia. A poorly sealed restoration could allow decay at the margins, which is why dentist expertise is important. Overall, complications are rare when the procedure is done by an experienced dentist.
How much do inlays and onlays cost in Arlington, MA?
In the Arlington/Boston area, porcelain inlays/onlays generally cost about $900–$1,400 per tooth. Composite inlays tend to be less expensive (often a few hundred dollars). Insurance typically covers a portion (often ~50%) of the cost for major restorations. Actual cost depends on your dentist’s fees, the tooth involved, and your insurance. It’s best to get a detailed quote and pre-approval from your insurer for your specific case.
How do I care for my inlay or onlay after the procedure?
Care for an inlay/onlay is the same as a natural tooth. Brush and floss daily, and maintain regular dental checkups. Avoid chewing very hard foods (ice, hard candy) on the restoration. If you grind your teeth, consider a night guard. With good oral hygiene, your inlay/onlay can stay in place for many years.
Does dental insurance cover inlays and onlays?
Most dental insurance plans cover inlays/onlays as they are considered major restorations. Coverage varies by plan, but many policies pay around 50% of the fee. Some plans have limits on frequency or total annual coverage. Always check with your insurer and dentist; they can often submit a pre-treatment estimate so you know your out-of-pocket cost in advance.
Q: What is a dental inlay?
A: A dental inlay is a custom filling made outside the mouth that fits into the grooves of a molar. It’s used when a tooth’s center is damaged but the cusps (points) are intact. Inlays strengthen and restore the chewing surface of the tooth.
Q: What is a dental onlay?
A: A dental onlay is like a partial crown. It covers one or more cusps of a tooth as well as the inner surface. Onlays are used when damage is too extensive for an inlay but a full crown isn’t needed. They cap the tooth’s chewing surface and are bonded in place.
Q: How long does the inlay/onlay procedure take?
A: If done traditionally, expect two visits: one for prepping the tooth and taking an impression, and another (1–2 weeks later) for placing the final restoration. Each visit is similar in length to a crown preparation or filling appointment (typically 1–2 hours). Some offices with CAD/CAM technology can do it in one visit (1.5–2 hours).
Q: How long do inlays and onlays last?
A: Porcelain inlays and onlays often last 15–30 years or more. Composite inlays may last 5–10 years. Gold inlays can last decades. With good oral hygiene, most inlays/onlays remain functional for well over a decade.
Q: How are inlays and onlays different from fillings?
A: Simple fillings (like composite or amalgam) are applied directly into a tooth cavity. Inlays/onlays are “indirect” – they are made outside the mouth for larger cavities. Inlays/onlays bond more strongly and preserve more tooth structure. They also typically last longer and look more natural than large fillings.
Q: Can I get a dental inlay if I have an allergy to metal?
A: Yes. Inlays/onlays can be made entirely of porcelain or composite resin, which are metal-free. Let your dentist know about any allergies; a non-metal inlay (ceramic or composite) can be used safely.
Q: Can dental inlays and onlays be whitened?
A: No. Once placed, the material color is permanent. Porcelain and composite do not respond to whitening agents. If you whiten your natural teeth, do it before getting the inlay/onlay so the dentist can match the shade. Avoid staining foods/drinks to keep the restoration’s color consistent.
Q: What happens if my inlay or onlay chips or falls out?
A: Contact your dentist promptly. Often a dislodged restoration can be re-cemented or replaced. If it chips, minor repairs may be possible with bonding material, but larger damage will require a new inlay/onlay. In the meantime, avoid chewing on that side and keep it clean.
Q: How do I know if I need an inlay or an onlay?
A: Dentists recommend an inlay/onlay when a cavity is too big for a conventional filling but the tooth can still be saved without a crown. If the damage is moderate (e.g. on a molar’s biting surface), an inlay/onlay is ideal. If decay extends to one or more tooth cusps, an onlay is chosen. Your dentist will examine your tooth and X-rays to decide the best option.
Q: Does the tooth need to be numbed for an inlay/onlay?
A: Yes. Local anesthesia is used so that drilling and restoration placement are comfortable. You should not feel pain during the procedure. Afterward, any soreness is usually mild and temporary.
Dental inlays and onlays offer a durable, natural-looking solution to restore damaged teeth while preserving their structure. Whether you’re dealing with a cracked tooth, decay, or worn enamel, this treatment provides both functional and aesthetic benefits. At Arlington Dental, our team specializes in custom-crafted inlays and onlays, ensuring each patient receives personalized care tailored to their unique needs.
If you’re considering inlays or onlays or want to learn more about how they can enhance your dental health, don’t hesitate to reach out. Arlington, MA dental care is available at Arlington Dental, 43 Broadway, Arlington, MA 02474. (781) 641-0500 to book with our dentist today.
