Fixing a seriously damaged or decayed tooth is not straightforward, especially when the hole is too large for a simple filling but too small to justify shaving healthy enamel for a dental crown. You may be too nervous to damage your natural tooth structure with brutal procedures that destroy the healthy tissue.
Luckily, the ideal solution is custom-made dental inlays and onlays. These restorations restore only the lost parts of your tooth while preserving your natural enamel. With this dental treatment, you can rebuild your bite’s strength and function without needing a full crown. Your long-term oral health is guaranteed by SoCal Dental of Agoura’s vast experience with inlays and onlays.
Inlays vs. Onlays
To learn the functionality of these restorations, you should understand your dental structure. The back teeth, molars and premolars, have complex chewing surfaces with ridges, fissures, or grooves. The position and extent of your tooth decay will dictate the architectural style your dentist will use.
Since conservative dentistry aims to fix only the parts of the tooth that are damaged or infected, your dentist will check the strength of your enamel to determine whether the repair should stay inside the tooth or extend to the biting edges.
It is this strategic positioning that makes the two restorative processes different, so you can enjoy the support needed to restore your tooth without unnecessary modification of the healthy portions of your enamel.
Dental Inlays
When bacteria invade your tooth’s chewing surface and form a hole inside, you will need a dental inlay. The restoration fits perfectly into the hole cut in the center of your tooth. During the preparation stage, your dentist carefully scrapes away the rotten tissue without damaging the healthy cusps around it. A clean, steady internal cavity remains and is ready for the insertion of the laboratory-made porcelain or gold block.
When this restoration is permanently fixed in the prepared space, it serves as an internal brace, which significantly strengthens the integrity of the structure of your molar. Since the inlay fits snugly within the edges of your tooth, it relies on them for side support and also stops those walls from collapsing inward when you chew hard food.
Dental Onlays
When your dental damage is far more serious and protrudes outward, weakening one or more of the elevated biting peaks, your dentist will change the treatment plan to a dental onlay. Dental professionals often refer to an onlay as a partial dental crown, since it is specifically designed to cover the biting surface of the molar and shield the vulnerable cusps against catastrophic fractures. Whenever you chew tough food, your molar cusps have to endure a high volume of local pressure.
If a cusp has been undermined by a large area of decay or a huge, old-fashioned silver restoration, that ridge is vulnerable to shearing away altogether. The onlay helps protect the weak part of the tooth by covering it with a strong material that distributes the chewing pressure.
This procedure achieves a spectacular level of dental enamel preservation because you are merely filling in the top portion of the tooth that has been lost, leaving the healthy side walls fully intact and undisturbed.
Why Pick Indirect Fillings as Opposed to Direct Fillings?
When choosing the ideal restorative method for a damaged tooth, you should assess the mechanical constraints of the conventional composite fillings. Below are the reasons for selecting indirect over direct fillings:
Getting Rid of Shrinkage and Marginal Leakage
Once a direct composite filling is blasted with a curing light, the chemical reaction will make the resin shrink slightly as it hardens. This shrinkage in a large cavity causes the filling to pull away from the inner walls of your tooth, leaving microscopic gaps along the restorative margin.
These unseen cracks allow invasive oral bacteria to penetrate, causing a destructive process called microleakage. Over time, this bacterial infiltration leads to rampant secondary decay below the filling, which, in most cases, destroys the tooth internally before you even notice there is an issue.
This type of decay is a risk you avoid entirely by opting for an inlay or onlay, which are custom-made dental restorations that fit precisely into the tooth structure. Since the piece that comes out of the laboratory is fully cured and dimensionally finished, it does not shrink during bonding. This attribute prevents marginal leakage, and the interface between your enamel and the restoration is completely sealed against bacterial invasion.
Structural Reinforcement
When restoring teeth, consider the physics of your bite and its effect on the teeth’s structural integrity. When you place a large direct filling in a molar with a cavity, it can act as a mechanical wedge. Whenever you squeeze your jaw, the pressure pushes the soft stuff outwards against the weak enamel walls of your tooth, gradually forcing the tooth open until it finally breaks down the center. You entirely turn this ruinous physics upon itself by choosing an indirect restoration.
With dental bonding, your dentist chemically bonds the solid inlay or onlay to your natural enamel. Rather than forcing the tooth open, this high-strength adhesive resin forms an effective cohesive pull that permanently holds the opposing walls of your tooth together. This teamwork of biological and mechanical processes not only restore your tooth to its original condition but also turn a fragile tooth into a solid structure capable of withstanding significant pressure with minimal effort.
What Material Should You Consider?
You can choose from a variety of restorative materials for your inlay or onlay. Each has highly specific clinical benefits depending on your anatomy. Your dentist will assess your bite strength, aesthetic values, and the exact position of the damaged tooth to suggest the best structural compound that suits your particular case.
Common materials include:
Porcelain and Ceramic
If your primary goal is a completely invisible restoration, you will likely use high-grade porcelain or glass ceramics. Modern dental porcelain mimics natural enamel, with translucency, texture, and light-reflecting properties that match those of your surrounding teeth.
Your master ceramist will carefully apply the porcelain to one of the shades and color gradients of your smile, ensuring that the inlay or onlay fits so well that you will barely be able to tell which tooth was fixed.
In addition to being beautiful, porcelain is quite durable and resistant to stains. The surface becomes completely non-porous as a result of being fired and glazed at extremely high temperatures in a laboratory kiln. It implies that you can consume coffee, tea, and red wine without fear that your restoration will take on dark colors or lose its luminous, natural look over time.
Zirconia
Your dentist will strongly recommend zirconia onlays if you need high biting forces or a large restoration on the far back molars. Zirconia is a crystalline ceramic commonly known in the dental fraternity as “ceramic steel” due to its near-invincibility. A solid zirconia block is much stronger and less likely to break than regular layered porcelain, which can chip under high pressure.
This material is strong, and the laboratory technician can make a much thinner restoration. Your dentist can be more conservative during preparation, leaving more of your natural tooth structure intact. Moreover, advances in materials science have enabled producers to make highly translucent zirconia, so you get the same industrial strength with the natural, tooth-like appearance you want for a smooth smile.
Gold Restorations
Do not dismiss the clinical benefits of gold dental restorations just because they are not white like your natural teeth. Highly pure dental gold alloys have been successful in terms of restorative longevity. Gold remains the ideal choice of alloys to use in reconstituting molars in the posterior part of the mouth. Gold has a physical property called “malleability,” which allows the metal to be perfectly burnished and adapted to the microscopic edges of your teeth.
This procedure creates an airtight seal with such precision that it nearly guarantees the prevention of recurrent decay. Gold’s wear rate and thermal expansion coefficient are nearly identical to those of natural human enamel. Therefore, when you chew, the gold restoration automatically adjusts itself without overworking the other teeth in your opposite jaw, which guarantees you a lifetime of functional harmony and structural perfection.
The Clinical Restoration Process
The clinical experience of having a custom inlay or onlay is a combination of medical accuracy and high-level engineering. Your dentist will take you through the restoration process, depending on the technology they have and the complexity of your case.
The Precision Laboratory Workflow
When your dentist uses the traditional two-visit lab procedure, you benefit from the master artistic talents of a dental ceramist.
- The first appointment with your dentist involves:
- The careful application of a local anesthetic to the area,
- The dentist’s removal of the decayed tissue, and
- The refinement of the inner geometry of your tooth.
Your dentist will then make a comprehensive physical impression of your tooth using a special dental silicone. This impression is an accurate physical negative of your prepared tooth and the surrounding bite landscape. Although the impression is dispatched to a dental laboratory, your dentist will make and install a temporary composite restoration to cover your exposed dentin and to preserve your chewing ability.
Over the next two weeks, the master ceramist will cast a stone model of your mouth and carefully hand-carve your permanent inlay or onlay from several layers of porcelain to achieve the ideal functional lines and aesthetic shades.
- Your second visit will be to remove the temporary and permanent bonding of your handcrafted restoration.
CEREC CAD/CAM Technology
You have a chance to skip the conventional laboratory waiting period when you have a dentist with CEREC same-day restorations. This incredibly sophisticated CAD/CAM dentistry workflow will transform the patient experience by condensing a two-week procedure into a seamless one-appointment experience. Your dentist will employ a highly advanced intraoral wand to take rapid digital impressions of your teeth.
This fast optical scanner takes a thousand or more microscopic images in a span of a second, which immediately creates a perfect, full-color, three-dimensional model of your ready tooth on a computer screen. The dentist can create your custom restoration with extreme precision using specialized software.
After the virtual blueprint is completed, the information is wirelessly sent to a dental milling unit in the office. The model is carved from a solid block of high-strength ceramic, allowing it to be shaped into a perfectly flawless inlay or onlay using diamond-tipped burrs in less than 20 minutes.
Science of a High-Strength Adhesive Bonding
The last part of the process, which is called adhesive bonding, involves a complex chemical fusion process. To start with, your dentist isolates the tooth to prevent moisture contamination and applies a mild acidic etching gel to the enamel surface. This etchant leaves millions of microscopic holes on the surface of your tooth.
Then, your dentist places a sophisticated dental adhesive resin that flows deep into these microscopic pores, forming an interlocking micromechanical bond. Your porcelain or zirconia restoration has a similar interior surface, which is treated with a special silane coupling agent.
Once the restoration is firmly in place in the tooth, a powerful ultraviolet light is used to set the resin cement, quickly connecting the tooth’s molecules with those of the ceramic. This forms a permanent, monolithic structure that cannot be infiltrated by bacteria and can withstand high occlusal loads.
Are You Eligible to Have Inlays & Onlays?
You should undergo a thorough clinical assessment to determine whether an indirect restoration is an appropriate treatment for your dental problem. Not all broken teeth qualify for an inlay or onlay, and your dentist should determine the exact amount of lost tooth material and the overall condition of the supporting enamel before prescribing this less radical treatment.
The 50% Damage Rule and Structural Integrity
When assessing if your dental enamel can receive an indirect restoration, you will hear dental professionals mention the so-called fifty percent rule. When the width of your cavity or the footprint of your failing silver filling is over half the distance between your antagonistic cusps, a direct composite filling is no longer a clinical option. At this 30% to 50% damage level, the rest of the outer walls of your enamel are thin and vulnerable to outward flexing during the chewing cycle.
In this case, use an inlay or onlay, as only the rigid, lab-made block can support the internal walls and prevent them from collapsing or fracturing. However, if you have lost more than three-quarters of your clinical crown and only 75% of the tooth remains, the bone will not support an onlay, and your dentist will need to recommend a full-coverage dental crown to protect any healthy tissue above the gum line that is safe.
Contraindications
You have to be entirely open with your dentist about your daily lifestyle practices, since some subconscious practices may significantly compromise the effectiveness of your restoration. If you have severe bruxism, the chronic, automatic habit of biting and grinding teeth furiously, particularly during sleep, you might have a clear contraindication to the usual porcelain restorations. You produce massive quantities of occlusal pressure in one of your bruxism spurts, and this can easily break a tough ceramic onlay.
This issue does not mean you cannot receive conservative care, but it will significantly alter your treatment plan. Your dentist will likely recommend a high-quality zirconia or flexible gold restoration and will definitely require a custom acrylic night guard to protect your investment from bruxism.
Also, if your outer enamel is badly damaged by strong acid or serious gum recession, you might not be a good candidate for a dental implant because the bond’s strength depends on having healthy enamel.
Longevity and Post-Treatment Management
Your high-quality inlay or onlay will serve you without any fault for two to thirty years, and in most instances, the rest of your life, should you maintain a strict and regular program of oral care. Laboratory-made porcelain, zirconia, or gold is completely resistant to biological deterioration.
Still, the natural tooth structure that forms the edges of your restoration is susceptible to attacks by bacterial acids. The most important variable in the long-term success of your dental work is your commitment to post-treatment care.
Navigating Post-Operative Thermal Sensitivity
You are expected to be completely ready to undergo a short-term phase of mild-to-moderate postoperative tooth sensitivity right after the permanent bonding of your new restoration. Extracting your tooth requires removing deep decay, which in most cases is close to the inner pulp chamber, where your tooth’s sensitive nerves and blood vessels are located. Furthermore, etching is a chemical process that temporarily opens the microscopic dentin tubules connected to the central nervous system.
The first two weeks of healing will usually be marked by a sharp, transitory zing when you take beverages that are highly chilled, hot coffee, or sweet foods. This temporary pain can be easily managed by applying a special desensitizing toothpaste containing potassium nitrate, which calms irritated nerve endings.
When your tooth naturally creates a protective layer of secondary dentin inside the pulp chamber, this temperature sensitivity will completely go away, resulting in a tooth that feels comfortable and works well without needing extra special care.
Maintenance Protocols for Lifelong Durability
To avoid needing a full-coverage crown later, take good care of your new tooth. Your daily routine for restoring your teeth should include thoroughly cleaning them with a non-abrasive fluoride toothpaste. You should brush your teeth at least twice a day and floss around the edges of your inlay. Clean your tooth surface at least once a night to loosen food particles and remove the acidic dental plaque that can stick to your teeth.
Do not use your teeth as mechanical instruments, such as to open plastic packaging, bite your fingernails, or crush hard ice cubes or hard candy, as these actions will inevitably cause microfractures in your ceramic restorations over time.
Above all, maintain a strict routine of professional cleaning and twice-yearly check-ups with your dental hygienist. These visits enable your dentist to perform high-resolution digital X-rays to assess the integrity of the bond, ensuring this alternative to high-quality dental crowns protects your health and keeps your smile flawless.
Find a Dentist Near Me
Selecting a high-quality dental restoration is an important investment in the structural integrity and long-term health of your smile. With a moderate case of decay, you can resolve the issue using a specially designed inlay or onlay to restore the tooth. These tough restorations strengthen your teeth against the high pressures of everyday chewing, reducing your chances of fracturing again.
Structural tooth damage should be treated promptly, as in most cases, delaying treatment can lead to serious complications, such as deep nerve infections, which may require root canals or the removal of the tooth altogether. Do not wait for a controllable fracture to turn into an agonizing dental emergency.
At SoCal Dental of Agoura, we are knowledgeable in advanced restorative dentistry. Our dentists will examine your condition, determine your candidacy for inlays & onlays, and explain suitable dental treatment methods. Call us now at 818-597-0100 to schedule an appointment to save your smile.
