Inlays vs. Onlays: Understanding the Distinctions and Choosing the Right Option for You

Inlays vs. Onlays: Understanding the Distinctions and Choosing the Right Option for You

May 01, 2024

Inlays and onlays are essential dental restorations that can significantly impact oral health and smile aesthetics. When faced with tooth damage or decay, understanding the differences between inlays and onlays is pivotal for making well-informed decisions about your dental care. In this blog, we will dive into the intricacies of these restorations, exploring their unique features, benefits, and indications. Whether you are seeking to repair a cracked tooth, replace a large filling, or enhance the appearance of your smile, we are here to provide valuable insights and guidance. 

What Are Inlays?

Inlays are indirect restorations designed to repair moderately damaged or decayed teeth. These are individually crafted in a dental lab before being affixed to the tooth surface. Inlays are used when the damage does not extend to the tooth cusps. These restorations are made from durable materials such as porcelain, composite resin, or gold, providing strength and durability while blending seamlessly with natural teeth.

What Are Onlays?

Onlays, sometimes referred to as partial crowns, resemble inlays but encompass a greater area of the tooth. They are used when the damage or decay extends to one or more of the tooth cusps. Onlays provide additional support and protection to the tooth, preserving its integrity and function. Like inlays, onlays are custom-made to fit the specific contours of the tooth and are crafted from materials including porcelain, composite resin, or gold.

What Are The Material Options for Inlays and Onlays?

  • Porcelain: Porcelain inlays and onlays provide both strength and a lifelike appearance, closely mimicking natural tooth enamel. They are a superb option for repairing front teeth or those visible when smiling.
  • Composite Resin: Composite resin inlays and onlays provide versatility and can be color-matched to blend seamlessly with the surrounding teeth. They are an ideal option for restoring teeth in more visible areas of the mouth.
  • Gold: Gold inlays and onlays are renowned for their robustness and durability. Although they may not match the aesthetic allure of porcelain or composite resin, they excel in resilience and resistance to wear, making them ideal for repairing rear teeth exposed to significant chewing pressure.

What Are The Indications for Inlays and Onlays?

Inlays and onlays are recommended for various dental issues, including:

  • Moderate to Severe Tooth Decay: When a tooth has decayed beyond what a dental filling can adequately restore, inlays and onlays provide a more substantial and durable solution.

  • Fractured or Damaged Teeth: Teeth with fractures or structural damage, such as cracks or chips, can benefit from inlays and onlays to reinforce and protect the remaining tooth structure.

  • Large Old Fillings: In cases where large or failing fillings need replacement, inlays and onlays offer a more conservative alternative to dental crowns while providing additional support and protection.

  • Cosmetic Enhancement: Inlays and onlays can serve cosmetic functions by enhancing the look of stained or irregularly shaped teeth while conserving the natural tooth structure.

What Are The Advantages and Disadvantages of Inlays?


  • Conservative Approach: Inlays preserve a more natural tooth structure compared to traditional fillings, making them a more conservative treatment option.
  • Durability: Inlays are made from durable materials such as porcelain or composite resin, providing long-lasting restoration.
  • Custom Fit: Inlays are custom-made in a dental laboratory to precisely fit the prepared cavity, ensuring optimal function and comfort.
  • Strengthens Tooth Structure: Inlays strengthen and reinforce the tooth structure, reducing the likelihood of additional damage or decay.


  • Multiple Appointments: Inlays typically require two dental visits for preparation, impression, and placement, which may inconvenience some patients.
  • Cost: Inlays may be more expensive than traditional fillings due to the custom fabrication process and use of high-quality materials.
  • Sensitivity: Some individuals might encounter transient sensitivity following the placement of inlays, typically resolving spontaneously.

What Are The Advantages and Disadvantages of Onlays?

Advantages of Onlays

  • Biocompatible bonding: Onlays are securely bonded to the tooth surface using biocompatible dental adhesives, ensuring a strong and durable bond.
  • Resistance to staining: Porcelain onlays exhibit exceptional resistance to staining caused by food and drinks, preserving a brighter and whiter appearance for an extended period.
  • Minimal post-operative sensitivity: Patients often experience minimal discomfort or sensitivity following the placement of onlays, allowing for a smoother recovery process.
  • Versatility: Onlays can be used to repair large cavities, cracks, or fractures on the chewing surfaces of molars and premolars, restoring both function and aesthetics.

Disadvantages of Onlays

  • Risk of recurrent decay: If the margins of the onlay are not properly sealed, bacteria can infiltrate underneath, leading to recurrent decay and the need for further treatment.
  • Allergic reactions: While uncommon, a few patients may encounter allergic responses to the materials utilized in onlay production.
  • Discoloration over time: Onlays made from certain materials, such as composite resin, may gradually discolor or stain, requiring replacement for aesthetic reasons.

What Are The Considerations for Choosing Between Inlays and Onlays?

When deciding between inlays and onlays in Billerica, several factors should be taken into consideration, including:

  • Extent of tooth damage or decay
  • Location of the affected tooth
  • Aesthetic preferences
  • Budget considerations
  • Dentist recommendations and expertise

What Are The Procedure for Placement of Inlays and Onlays?

The process for placing inlays and onlays usually involves several steps:

  • Initial Consultation: The dentist in Billerica, MA, performs a comprehensive evaluation of the affected tooth and engages in a conversation with the patient about different treatment options.
  • Tooth Preparation: The dentist administers local anesthesia to numb the area before removing any decayed or damaged tooth structure.
  • Impression Taking: A dental impression of the prepared tooth is obtained either with dental putty or digital scanning technology to generate an accurate mold.
  • Temporary Restoration: A temporary restoration might be applied to the tooth to safeguard it during the fabrication of the permanent inlay or onlay at a dental laboratory.
  • Fabrication: The inlay or onlay is custom-made by a dental technician using the impression taken during the initial visit.
  • Placement: Once the permanent restoration is ready, the temporary restoration is taken off, and the inlay or onlay is securely attached to the tooth using dental adhesive.
  • Final Adjustments: The dentist checks the fit and bite of the restoration and makes any necessary adjustments for optimal comfort and function.
  • Polishing: The restoration is polished to achieve a smooth and natural-looking finish, blending seamlessly with the surrounding teeth.

What Are The Aftercare and Maintenance for Inlays and Onlays?

To ensure the longevity of your inlays and onlays, it is essential to practice good oro-dental hygiene habits and take good care of your dental restorations. Here is what you need to know:

  • Oral Hygiene: Incorporate regular brushing and flossing to keep the restoration and surrounding teeth clean and free from plaque buildup.
  • Avoid Hard Foods: It is important to avoid biting down on hard food items or objects to protect the restoration from potential damage.
  • Regular Dental Check-ups: Schedule routine dental visits with the dentist near you for professional cleanings and examinations to ensure the longevity of the inlay or onlay.
  • Mouthguards: Make sure to wear a mouthguard while participating in sports or physical activities that could potentially cause dental harm in order to safeguard your dental work.
  • Avoid Grinding Your Teeth: You might think about getting a nightguard if you grind your teeth often; it will keep the restoration safe from harm.


Inlays and onlays offer effective solutions for restoring damaged or decayed teeth while preserving natural tooth structure. By gaining a good understanding of the distinctions, advantages, and factors to consider for each alternative, you can make a well-informed choice regarding your dental care. At One Dental Care, our team of highly skilled professionals is committed to delivering individualized care and offering expert guidance to assist you in attaining excellent oro-dental health and a stunning smile. Contact us today to schedule your consultation and discover which option— inlays or onlays— is ideal for restoring your teeth. Let’s work together to achieve a healthier, more radiant smile that lasts a lifetime!