All That You Need to Know About Dental Inlays and Onlays

If you wish to preserve your compromised teeth and its natural structure, we strongly recommend that you look into getting inlays and onlays for them instead of going straight to dentures, bridges, crowns, and veneers.

Dental inlays and onlays make the treated area much easier to clean when compared to other restorative dental options. In addition, the material used for them typically does not shrink as time goes by. This is why they’re the preferred choice when it comes to molars and premolars (posterior teeth).

Dental Inlays and Onlays 101

A dental inlay or onlay might be suggested to you by your dentist at home or from Thantakit in Thailand (care of a dental tour package) if your tooth decay is too large for a filling but still salvageable without resorting to getting a dental crown or doing a root canal.

• Neither Mild Nor Severe: A severe cavity or multiple cavities might require drastic actions to save the tooth ranging from a crown, extraction, or a root canal. A mild cavity can be fixed with fillings. Inlays and onlays fix mid-sized cavities.
• More Natural in Aesthetics: Porcelain is used over metal due to its better aesthetics and decent durability. It’s not as comparable in toughness as metal but it is comparable to the tooth’s natural enamel outer shell, at least. It delivers the following benefits:
• Durability
• Natural appearance
• Long-lasting toughness
• Wear-resistant enough like metal
• Blends well with your remaining tooth
• Onlays are More Crown-Like: An onlay is like a “crownier” version of the inlay. It’s also placed atop the tooth and it’s usually even placed right on the tooth’s top part or crown (not to be confused with a dental/prosthetic crown) but it doesn’t cover the whole tooth like a cap.
• Bigger-Scale Treatment: An inlay deals with smaller yet deeper cavities but those can only go so deep until a root infection develops and a root canal is required. Onlay treatments are thus considered bigger-scale. They’re made for single-tooth restorations that don’t quite call for synthesizing a new crown.
• Somewhat Larger Areas of Tooth Decay: Dental crowns are for teeth that have undergone root canals or barely have any structure left. Onlays are for larger caries that don’t respond well to inlays or fillings because much of the tooth requires removal.
• Outer Cusp Instead of Inner Hole Filling: Onlays are placed on the outer cusp of a compromised tooth that could still be saved with it instead of the area between cusps. An onlay is made of a single, solid porcelain piece like a crown versus that of teeth filling.

The Pros and Cons of Inlays and Onlays

Here are the benefits and drawbacks of availing of either an inlay or an onlay for your posterior teeth that have cavities or dental caries in them.

Type of Procedure	Pros	Cons
Inlays	An inlay is much smaller than a crown denture. It’s placed on bigger cavities running deep into the tooth’s crown and dentin. They’re better than fillings at filling in deep cavities.	An onlay covers more wide space than an inlay but choosing between either depends on cavity shape anyway. A crown tends to cover the whole tooth, thus protecting it more.
Onlays	An onlay is even bigger than the inlay, ensuring better coverage. It covers most of the crown but not the totality of the tooth. You can use it to cover the cavity that has eaten up most of the tooth’s crown.	An inlay is more of a perfect fit for deep cavities that haven’t reached the tooth root. It also only covers the top part of the tooth so a crown has superior coverage compared to it as well.

Points of Comparison for Inlays and Onlays

A dental filling is best used for most minor cavities. However, major tooth decay might call for a dental crown. Or you could instead get a dental crown after an endodontic (root canal) treatment.

• The Differences of Inlays and Onlays: Inlays work on deeper cavities that almost reach beyond the dentin to the root but not quite, so you can still fix them without resorting to a root canal treatment. Onlays work on wider cavities atop the tooth’s crown.
• The Similarities to Crowns: Inlays and onlays are similar to crowns in that they need to be fabricated. They can be considered partial crowns that you can put on your dental caries or tooth cavities like crowns, but they fit over the shape of the holes like tooth fillings.
• The Differences from Crowns: Inlays and onlays are smaller than crowns. A crown covers the whole prepped and shaven tooth (or what is left of it) like an oversized cap. Or it could connect to a dental implant where the cavity-ridden teeth used to be.
• The Similarities to Fillings: Like fillings, they cover the cavities of your teeth. They can also be made of metallic material, similar to dental amalgam but more like the material used on gold or silver crowns.
• The Differences from Fillings: Fillings are like plaster. They can work well in plugging up holes on the wall, but they crumble when you use them like concrete. Inlays and onlays are standalone structures made with the same material as crowns so they’re less likely to crumble when covering up your medium-sized cavities.

Which Patients Are Eligible for Inlays and Onlays?

A great candidate for inlays or onlays is a patient with a greater degree of cavity size or deepness that cannot be supported by ordinary fillings, but there’s still enough of the tooth left to not require it getting covered by a bridge or crown.

There should be enough of the tooth remaining to adequately support the onlay or else your dentist might need to look into getting a crown, bridge, or a dental implant if the diseased tooth requires extraction too.

Traditional Fillings versus Inlays and Onlays

Dental caries don’t seem like a big deal when they first appear. However, like roadside potholes, they get worse over time to the point where the suffering tooth could be compromised.

• How Do Caries Happen? They happen when you don’t brush your teeth enough. Your teeth get plaque (a yellow film of food deposits), which serves as food for bacteria. In turn, these germs produce acidic waste products that compromise the enamel or outer shell of your tooth.
• Tooth Cavities are Tooth Holes: Your teeth develop holes from the waste products of bacteria that live in your teeth. If you don’t brush, floss, and/or gargle mouthwash regularly, the bacteria population can become so bad that your teeth start decaying.
• What Are Fillings? Dental fillings are your first line of restorative dentistry defense against cavities and tooth decay. In modern times, they are more discreet than ever before. They can fill up your holey teeth like asphalt or plaster over potholes or wall holes.
• What Are Fillings Made Of? They use materials like composite resin that’s tooth colored (acts like tooth plaster) or amalgam (liquid mercury and powdered alloy). Resin is more aesthetically pleasing while amalgam is more resilient against back teeth bite forces.
• How are Fillings Placed? Fillings are placed by first having the dentist remove the decayed portions of the tooth then putting in the composite resin (more natural-looking) or amalgam (sturdier) over the prepped tooth.
• When to Use Fillings: Fillings are best used to cover small cavities. They can last for many years depending on how you’ll take care of your teeth after the decay starts. The wider the cavity the less effective they become compared to inlays and onlays.
• Why Do You Need to Plug Up Cavities? The bigger the cavities and decayed tooth material, the weaker your damaged teeth will become, which could lead to root infection that requires either a root canal to save the tooth or tooth extraction to remove the nerve pain.
• Fillings Can Make Cavities Worse: What’s worse is that the more you replace the fillings on a cavity the more the dentist will have to drill the tooth to make the replacement filling fit, which actually worsens the cavity. Don’t let it impact your smile, confidence, and quality of life! Have it fixed today!

What to Expect of the Operation

Both procedures require the dentist to remove the decay from your tooth and allow the surface to be prepped for inlay or onlay placement. Like fillings, they fill the cavities effectively in order to seal the tooth from further tooth decay.

A traditional filling uses composite material or amalgam to fill the gap. It’s a much quicker process. With inlay and onlay operations, it’s longer and requires fabrication of the material in question.

They’re mostly different in terms of how the space of the cavity is filled. Inlays are for deep cavities. On the other hand, onlays are for wide outer-cusp cavities. Meanwhile, fillings are for minor cavities. Crowns cover the whole tooth, which now serves as its anchor to your jawbone.

The Dental Inlay or Onlay Process

A single, solid piece of porcelain is placed on the prepped tooth. This material is fabricated off-site in a dental lab after a mold or scan is taken of the cavity with all the decayed material removed.

• Fabrication: The inlay (for deep cavities) or onlay (for wide cavities) needs to be fabricated like a crown. However, they’re fasted to fabricate into a solitary piece of ceramic porcelain due to their size when compared to a crown that covers a whole tooth.
• Made of Ceramic Porcelain: The dentist fabricates the inlay or onlay from ceramic porcelain. It’s supposed to match the exact shape and size of the cavity after all the decay had been drilled out. They’re secured in place with a special dental cement, just like a crown.
• Used to Be Made of Metal: “Classic” fillings, onlays, and inlays were made of metal. With fillings, it’s metal amalgam using liquid mercury. With onlays or inlays, it’s metal filling in a mold of the cavity before being placed on the tooth.
• The Custom Design Process: It’s necessary to wait for the inlay or onlay to get fabricated because they’re customized or tailored to fit the exact shape and size of your teeth in a way that doesn’t alter your natural bite or jaw structure.
• Customization Prevents Mishaps: The custom design process also prevents slight gaps to form, which allows food, plaque, and bacteria to form like an untouched Petri dish that’s hard to clean with dental floss or a toothbrush.

While it’s laborious to remove dental decay, have to make molds or scan the cavity, and wait for the inlay or onlay to get made in an off-site lab, it’s all worth it. It prevents a botched job and further decay down the line.

How are Inlays and Onlays Done?

Two appointments are required for inlay and onlay treatment. It’s all about removing the damage and sealing it with a tooth-colored porcelain replacement cemented into place to form a seamless bond without any gaps.

• First Appointment: The area with the affected tooth will be numbed with local anesthetic. This is the preparatory or prepping stage for the tooth.
• The decay or damage will be drilled out then cleaned up to allow for stable support for the inlay or onlay.
• Dental putty is put over the teeth with the prepped cavity to make an impression or mold of the damaged teeth.
• There are clinics that even use CAD/CAM (Computer Assisted Design/Manufacturing) to make the mold.
• The mold is sent to the lab where they’ll fabricate a piece of porcelain into an inlay or onlay or 3D print the same thing according to CAD/CAM data.
• A temporary cap or crown is placed over your prepped tooth.
• Second Appointment: The inlay or onlay is placed by dental cement at this final stage of the operation.
• The temporary cap or crown is removed to do a test fit of the inlay or onlay.
• If the fitment isn’t perfect, smoothening up the area might be called for.
• Once there’s a perfect fit between your damaged tooth and the inlay or onlay, dental cement or a strong resin adhesive is placed with the restoration to make it stick to the cavity.
• The treatment is then finished by polishing the new structure to look seamless when all is said and done.

Why Use Inlays and Onlays?

Inlays and onlays are a tougher enamel and dentin replacement compared to teeth filling material because of their toughness and ruggedness. They’re made of sterner material—ceramic porcelain—that’s less likely to buckle against bite forces.

Here are some important things you need to keep in mind:

• Normal chewing won’t break down the inlay or onlay.
• Wider cavities get fixed by an onlay and dental cement.
• Deeper cavities get fixed by an inlay and dental cement.
• They won’t shift into position due to the bite forces of your front or back teeth.
• The structure of your teeth is better preserved with these restorative techniques.
• Porcelain is more aesthetically pleasing and natural-looking compared to amalgam or composite material.

For Good Measure

No two cavities are alike. Therefore, no two solutions to fix cavities should be alike. Not all cavities can be filled with teeth filling. Your expectations in fixing your holey teeth might be something unexpected altogether.

Inlays and onlays are best used for cavities that are neither severe nor mild. They’ll serve as your tooth’s new loyal partner when it comes to returning its functionality and aesthetics when you put them on.

Thantakit International Dental Center is Thailand’s longest established dental center. Situated in Bangkok, our clinic is renowned across the world as a destination for world-class dentistry, with most of our patients flying to us from Australia.

Please contact us today and get a FREE dental consultation.