Dental Bridges, Crowns & Implants Explained

A crown or cap covers a single tooth, a bridge covers multiple teeth, and implants replace missing teeth as a root substitute. Implants can replace single, multiple, or an entire arches of missing teeth.
We will examine the various types, their placement, adjustment procedures and functionality.

1. What are Crowns & Bridges? 

Dental crowns and bridges cover and encase a damaged, chipped, broken or weakened tooth. They provide strong, long-lasting and durable teeth replacement solutions. They are custom-made artificial teeth caps that restore damaged or decayed teeth' shape, size, strength, and appearance. Dental crowns are categorized into:

• Metal crowns
• Metal ceramic crowns
• Metal-Free crowns

• Metal Crowns:

  They are dental crowns made primarily of various metal alloys. These crowns are known for their durability and strength, which can easily bear chewing and biting forces. However, metal crowns have a metal look that may be less appealing than tooth-coloured options such as porcelain or ceramic ones. As a result, they are used for back teeth or areas that are less visible when smiling. Metal crowns are also known as full-cast non-precious crowns because they are made of non-precious metal alloys like nickel-chromium or cobalt-chromium. They are unsuitable for all as they can cause metal allergies in some. Titanium is considered to be a safe and non-allergic metal for dental restorations. However, titanium is more popularly used for dental implants than crowns. In addition, the cost of fabricating titanium crown is higher than other metal crowns as it requires specialized techniques and equipment for fabricating metal crowns.

• Metal-Ceramic Crowns:

  They are also known as porcelain-fused-to-metal (PFM) crowns. They are made of a metal base with a ceramic covering. The metal base is made from alloys like nickel-chromium or cobalt-chromium, and the outer layer consists of dental porcelain fused to the metal. The metal base gives the crown strength, and the porcelain gives it a natural appearance. Hence they are preferred over metal crowns. These crowns are suitable for front and back teeth as they resemble the teeth' colour. However, PFM crowns cannot be suitable for all as the metal base can cause allergies in some. In addition, a slight greying effect at the gum line can be caused by the metal framework underlying the porcelain and makes it visible. PFM crowns are also prone to chipping and fracturing

• Metal-Free Crowns:

  Non-metal crowns are made entirely of porcelain/ceramic materials, giving them a more natural appearance. Zirconia ceramic crowns are more popular nowadays because of their strength and durability. They are comfortable, non-allergic, and do not cause sensitivity. In addition, they are designed with CAD/CAM technology that fits perfectly well and gives a completely natural look. Certified zirconia crowns are the safest for teeth replacement. Illusion Zirconia Dental Crowns are one of the most reliable crowns as they come with lifetime international warranty and uses FDA and CE certified materials. These crowns can last a lifetime with proper care and follow-ups.

2. Crown Placement and Adjustment

Dental crown placement and adjustment are essential for the crown's proper fit, function and durability. A proper crown placement and adjustment procedure involves the following steps.

• First, the dentist prepares the tooth for any damage or decay, and then impressions or digital scans of the mouth are sent to the lab for crown preparation. Meanwhile, a temporary crown is placed on the tooth to protect it from further damage.
• Next, the crown is prepared in a dental laboratory using impressions or digital scans in a few weeks.
• A crown seat dental appointment is usually scheduled after the dental laboratory has finished preparing the permanent crown using impressions or digital scans. The specific timing and procedures may vary depending on the individual case and the dental practice protocols.
• Next, the dentist will ensure the crown fits accurately on the tooth, achieving proper crown margins and biting during the crown seating. To achieve a better fit and aesthetic result, the dentist may need to make crown adjustments or replace the crown if it is an under-contoured crown, which means that the crown does not match the natural colour, size and shape of the tooth. In addition, due to too much adjustment, the crown may feel submerged in the gum line.
• The dentist further ensures that the crown margin should be precisely fitted to the prepared tooth and form an appropriate tight seal. It reduces the risk of decay and infection by keeping bacteria and debris out of the space between the crown and the tooth.
• When the crown feels satisfactory, the dentist permanently fixes the crown onto the prepared tooth structure with dental cement or adhesive.

After the placement, the new crown feels tight at times, this discomfort resolves with slight adjustments, and the discomfort subsides within a few days as the patient adjusts to the new crown

3. Types of Implant Crowns

Dental implants are artificial roots that support false teeth. Implant crowns cover these dental implants. An implant comprises three parts: a screw made of metal, such as titanium, palladium, or platinum. The metal screw is surgically implanted in the jaw, acting as a tooth root, and is protected by an abutment. And it is covered by a custom-made tooth cap or dental crown. The dental crown covering the implant is called the implant crown. Here's an overview of implant crowns:Implant crowns can be divided into several types based on various factors, such as materials, fabrication methods, and attachment mechanisms.

• The types of implant crowns can be classified into metal, metal-ceramic, all-ceramic zirconia, hybrid or resin crowns, etc.

• Based on the fabrication method, the implant crowns are divided into cement-retained or screw-retained implant crowns.

• The material is the same. However, they have different names, like implant-supported crown high noble alloys or implant-supported porcelain ceramic crowns.

1. Screwmentable implant crown:

A screw-retained crown is a type of implant crown screwed to the implant. The crown has a hole in the biting surface that allows the screw to be tightened directly onto the implant abutment. This method allows for simple extraction of the implant crown because it can be removed by simply removing the screw. It also allows for any adjustment to the done to the crown. However, the access hole is visible in such crowns, which can be an aesthetic concern.

2. Cement-retained implant crown:

A cement-retained crown, also known as an implant-retained crown, is cemented to the implant abutment using dental cement for a secure bond. Implant-retained crowns are more visually pleasing because there is no visible access hole on the crown's biting surface. However, if the crown needs to be removed or replaced in the future, it has to be cut or drilled off, which may damage the crown or abutment.

Which is better, cement vs screw-retained implant crown?

The decision between a screwable implant crown and a cement-retained implant crown is influenced by several factors, including the clinical situation, aesthetic requirements, ease of removal, and the dentist and patient's preferences. Your dentist will evaluate your situation and advise you on the best option for your implant crown.

Implant Crown Delivery Steps

Several procedures are followed while delivering an implant crown to guarantee proper fit, appearance, and functionality. Here are the typical steps in the delivery of an implant crown

• The dentist will examine the implant site, abutment, and surrounding tissues to ensure they are sound and prepared for the final fitting before the crown is delivered. It could involve examining the abutment's fit, determining the bite, and confirming the aesthetics.

• The dentist will choose the right shade that complements the patient's natural teeth using shade guides, considering elements like tooth colour, translucency, and the teeth next to it.

• The implant crown is created in a dental lab using impressions or digital scans of the implant site. The crown is made specifically to fit the patient's case's precise dimensions and aesthetic requirements.

• The dentist schedules the try-in appointment for the patient and checks the crown's fit, aesthetics and alignment.

• The dentist makes the necessary changes for proper fit and bites if any adjustments are needed.

• The final step involves fixing the crown to the abutment by screwing or cementing. The implant crown must be appropriately seated to maintain stability, proper function and aesthetics and check and make the necessary changes if the implant crown is not fully seated.

The time taken for delivery of an implant crown may vary in each case depending on the number of variables, including the patient's ability to heal, the placement of the implant in the mouth, and any additional procedures or treatments necessary.