Dental bridges are meant to replace missing teeth by "bridging" the gap between two remaining teeth. This involves creation of a pontic, or false tooths with a dental crown on either side. The crowns are fitted over the remaining teeth to hold the false tooth in place.
When there are only teeth on one side of the gap, cantilever bridges may be given. cantilever bridges consist of two side-by-side crowns and only one is connected to the pontic.
A fixed bridge helps to
|Replace missing tooth/teeth.|
|Helps balance a normal bite.|
|Helps prevent undesirable stress on the dental ridge.|
|Prevents over-eruption of the opposing teeth.|
|Prevents drift and tilt of adjacent teeth.|
|Prevents tooth decay in adjacent drifted teeth|
|Retards onset of gum diseases |
To design a bridge, the dentist must reshape the teeth to make room for the crowns. The dentist then makes a mold of the teeth. This mold is then sent off to a laboratory, where the actual crowns and bridge are made.
These crowns and bridges require a bit of extra care in terms of oral hygiene. With such care, bridges can last up to several years. However, improper or infrequent brushing and flossing, irregular dental visits, and excessive sugar and starch intake can all bring untimely damage to the bridge
MATERIALS FOR DENTAL CROWNS AND BRIDGES
All Resin – These are the least expensive crowns. Today these are generally used for temporary or provisional coverage. But like most inexpensive things they do not last as long as other types of crowns.
Metals – These could include gold alloy and other base metal alloys. Metal dental crowns are by far the toughest. They can withstand daily wear and tear and they rarely break or chip.
A gold crown has some very distinct characteristics that make it a good choice
1. Gold Fits better: A well-cast gold crown fits considerably better then other materials. Because it fits better, it lasts longer! The bacteria we all have in our mouths have less access to the micro-margins.
2. Gold Is Strong And Flexible: Gold expands and contracts at the same rate as your natural tooth. This protects the gold crown from chipping, cracking or breaking; which can be a problem with other less versatile materials.
3. Gold Is Safe And Comfortable: Gold doesn't just look good--it feels good--because gold is remarkably compatible with the inside of your mouth. With many other metals, the likelihood of sensitivity or an allergic reaction is a significant risk for the patient. But not with gold.
However not all crowns with the color of gold are the same - The best of the dental gold is an alloy of many metals, (gold, platinum, palladium, silver, copper and tin) and are usually about 76% gold or a little over 18 carat. Some gold crowns are made of an economy gold and are only gold in color and don't possess the casting characteristics so important for a good seal at the edges. These cheaper gold-content crowns are on the order of ten carat and do not have the tissue tolerance and compatibility of a higher gold-content alloy
|Worn out teeth where creating additional space for porcelain is not possible. |
|Posterior teeth where esthetics are not the prime concern|
The only real drawback is that they look like metal and not a naturally white tooth.
Metal-Porcelain – They combine the strength of the metal along with the esthetics of porcelain. These are probably the most used crowns nowadays. Of course the porcelain is slightly more prone to chipping, but they are still tough.
There are different types of porcelain fused to metal dental crowns:
There is a choice in the metal
1. Precious alloy (89-92% gold alloy, yellow gold color)
2. Semi-precious alloy (54-62% gold alloy, "white gold")
3. Non-precious (metal alloys, stainless steel color)
Precious alloys with high gold and platinum content are most preferable. One such crown that is commonly used today is called Captek.
Captek is an 88% gold alloy, which uses a unique fabrication system to provide the most extreme combination of strength and esthetics. It is formed using capillary casting technology which provides its exceptional characteristics. Due to porcelain's translucency, Captek crowns are truly the most beautiful metal-based crowns and are highly recommended for all areas of the mouth, front or back.
The advantages of using Captek are many;
Biocompatible: Captek’s advanced gold material reduces the accumulation of harmful bacteria at the gum line by 90% compared to natural tooth structure.Superior fit: Captek fit is superior to all other restorations, This is due to the fact that there is virtually no expansion or contraction, as there is no casting of the metal.
Esthetics: Captek™ (capillary technology) offers patients the beauty, health and longevity of gold crowns and bridgework Because it is a high gold alloy, Captek can impart a natural hue to porcelain veneered crowns and bridges. The light-dispersion effects of Captek crowns are designed to mimic those of healthy natural tooth structure. There is no oxidation, so it will not lead to black lines at the gum margins
It can easily be used for single crowns, implants, and bridges both anteriorly and posteriorly.
The only reason we have gone away from gold under our porcelain fused to metal crowns is the high cost of gold.
Semi-precious metal offers a balance between esthetics and strength at a lower cost than precious metals. It resists oxidation, it casts more accurately than non-precious metal, and it is a very commonly chosen option. But it cannot provide the warmth and beauty of gold-lined porcelain crowns.
Non-precious alloys are made of low-cost metals and have been in use for many decades. They are more difficult to cast (shape) than softer precious metals and therefore offer a less precise fit. Non-precious alloys also tend to oxidize over time) which darkens their color even more and can even stain and "tattoo" the gum.
All Ceramic Crowns and Bridges (Metal Free ceramic crowns)
These are the best looking crowns, and probably the best value for your money as far as esthetics are concerned. Contrary to what might appear, these materials are extremely strong and fracture tough. The material can well sustain the masticatory forces, providing durable crowns and bridges with beautiful esthetic results. They can be conveniently and reliably used in any part of the mouth. These are also the preferred material of choice in patients with metal allergies. Metal free restorations are produced with the latest CAD/CAM technology ensuring precision of fit. Some well known Metal free systems used are
Procera® is a unique system from Nobel Biocare for the fabrication of esthetic and functional dental restorations.
Procera® offers you the optimal restorative system, including crowns, laminates, and bridges, for all indications and anywhere in the mouth. The combination of beauty and strength gives you a simple and predictable clinical procedure, excellent esthetic results and improved long-term performance.
No PFM ‘gray lines’ ever
With metal ceramic, soft tissue around the tooth can recede, over time, revealing the metal underneath as ugly gray lines. This simply can’t happen with Procera® because they are metal-free.
Procera® all-ceramic solutions are completely tissue-friendly. Your crown, bridge or veneer (laminate) integrates beautifully with its surroundings, encouraging gum to grow back up to the tooth, as it would naturally. And because they are bio-compatible, there are no allergic reactions, no sensitivity to temperature and no impact on taste.
Procera® solutions are precision-engineered in state of the art production facilities. And they fit so well you will forget they are there.
Procera® uses a unique system to subtly match your real tooth’s color and translucency so they’re almost impossible to tell apart from real teeth.
Cercon is a high-tech ceramic, Zirconium Oxide, which has already been proven in many extreme situations such as heat shields in the Space Shuttle, brake disks for sports cars and the spherical heads of artificial hip joints. Using cercon has many advantages.
1) Due to the white zirconium oxide milled substructure
2) Optimal shade match to the existing natural teeth
1) Verified by the medical application of zirconium oxide for about 20 years
2) No allergic reactions reported in the published literature
3) Good insulating behavior of the ceramic against cold/warm influences
4) Thanks to a smooth ceramic surface that supports good oral hygiene
5) No interaction with other dental materials
1) Thanks to the exceptional strength of zirconium oxide
2) High stability requiring minimum framework dimensions
Lava delivers the strength you’ve been looking for in an esthetic all-ceramic restoration. The Lava system combines CAD/CAM technology with a translucent zirconia framework that can be custom colored creating a restoration strong enough for long span bridges, with precise fit and esthetics your patients expect.
IPS Empress is an all-ceramic crown system that gives you exceptional esthetics plus strength. A proven ceramic alternative to metallic restorations, IPS Empress offers patient satisfaction with aesthetic, natural looking restorations, by the exclusive use of ceramic materials.
Individually colored tooth restorations can be reproduced in exact shape and shade. The result is an individually fabricated restoration with an excellent fit and all the characteristics of a natural tooth. Even when working in limited space, optimum aesthetic results can be obtained.
The Empress system produces crowns, inlays/onlays and veneers, providing one of the strongest all-ceramic restorations available.
The new all-ceramic system IPS e.max comprises highly aesthetic and high-strength materials for both the PRESS and the CAD/CAM technology. The system is versatile and economical.
e.max® ZirCAD is your proven alternative to PFMs. Its high-strength offers long-term reliability for anterior and posterior single unit and multi-unit bridgework.
e.max® Ceram is a Nano-Fluor Apatite Glass Ceramic which mimics the optical effects of natural enamel, creating patient-pleasing esthetics.
IN ceram is a material from Vita (Germany). The VITA all-ceramic systems can be used for for crowns, bridges, veneers and implant suprastructures. The advantages of the VITA all-ceramic system are:
VITA all-ceramic is absolutely biocompatible. Your well-being will not be impaired by allergic or undesirable reactions, such as metal taste.
Colour, shape and surface structure of your teeth are unique – just as you are. By selecting VITA all-ceramic, you will receive a high-quality restoration without any visible difference from the natural tooth structure.
Stability provides reliability
VITA In-Ceram provides reliability since this material has been used worldwide for more than 13 years and has proved its reliability in millions of cases. The long service life of VITA-In-Ceram restorations is mainly based on the high stability of the all-ceramic
Wol-Ceram is the first ceramic crown that allows you to prepare a conservative feather-edge or chamfer margin. Copings are made from Vita In-Ceram alumina material, which has been proven in clinical tests for over 12 years. The outstanding fit and strength are the result of the Electrophoretic ceramic process resulting in excellent marginal integrity. Wol-Ceram’s beautifully natural esthetics result from a dentin colored coping that prevents opaque show-through.
REPLACEMENTS BY REMOVABLE TEETH
COMPLETE DENTURES: This is the most economic and most traditional method of tooth replacement. Dentures are removable objects that simulate the look and function of the tooth and its surrounding tissue. Most dentures are constructed with acrylic resins along with some composite materials. However patient can chose from a variety of options:
|Traditional plastic denture|
|Traditional plastic denture with a metal framework to make the denture strong, light and of course biocompatible.|
|Flexible denture(valplast) combined with metal framework|
Dentures can also be fixed now by use of dental implants.
For details Click here
There are two major types of dentures. The full denture replaces an entire jaw’s dentition, while a partial denture only replaces multiple or single teeth where there are still healthy teeth present. A partial denture also serves as a spacer to prevent the living teeth from shifting position.
Most patients of full dentures are in their later years and have lost most of their teeth. Patients of partial dentures are usually people who have lost a tooth to gum disease or injury. All patients receiving dentures find that their chewing improves, their oral hygiene becomes easier, and their speech clears up. On the outside, a denture can drastically improve your smile.
Dentures are specifically made for each patient’s unique anatomy. Initially they will feel awkward, no matter how well they may fit you. The fact remains that it is not a living part of your mouth and it will feel foreign to you. However, after a short period of adjustment most people don’t even notice that they’re wearing the dentures anymore.
Regular checkups with your dentist are encouraged in order to track changing conditions in your mouth. Should your teeth shift or your bones change shape with time, you’ll need a new set. Dentures have been around for a long time and are a proven way to replace lost teeth. If you require dentures please contact a dentist for a consultation.
THE PLASTIC REMOVABLE PARTIAL DENTURE
This is the least expensive of all the removable partial dentures. These dentures are generally used for temporary or intermediary purpose until the final prosthesis is made. Still yet we find many people keep this type of appliance for many, many years, just like permanent ones because as long as they are properly maintained, they look outwardly as good as the more expensive permanent appliances. The one pictured above replaces 4 missing teeth, leaving spaces for 7 natural teeth. Two of the natural teeth are clasped with wrought wire clasps which are cured into the structure of the denture base.
The pink material of the denture base is hard plastic and the same material used to make complete dentures. The main single advantage to this type of RPD is the cost. Also the new teeth and new denture base can easily be added to an existing treatment RPD. These are frequently fabricated even if the remaining teeth have existing decay or periodontal disease and their prognosis is doubtful. If later in the course of treatment some of the existing natural teeth are extracted for any reason, new false teeth can be added quickly to the partial, maintaining the patient's appearance.
Another common and infact more important use of these appliances is as an "immediate partial denture". This means that the appliance can be made before the teeth are removed, and inserted immediately after the extraction of the planned teeth so that the patient is never without teeth. This is of special help when anterior teeth are to extracted and patient wants to return back to his/her normal routine immediately.
However in spite of these advantages they have a number of disadvantages too.
They are basically plastic and due to their irregular shape, these partials tend to break frequently, especially those made for the lower arch. (Full dentures are more regular in shape and tend to be fairly strong as a result.)
These appliances are less stable compared to cast partials. Also cases of allergy to this material have also been reported.
As the gums resorb, the false teeth tend to sink below their original level making it necessary to reline them frequently, and sometimes even to reset the teeth which adds to their expense.
They are most frequently retained with wire clasps. These are frequently unsightly due to the limitations that pertain to their placement.
CAST METAL REMOVABLE PARTIAL DENTURE
These Removable Partial Dentures are cast metal frameworks made of chrome cobalt.These frameworks are cast to fit the teeth .These are cast very thin and are much less likely to break than the all plastic variety. For the same reason they are much less noticeable to the tongue.
The teeth have to be altered slightly beforehand in order that the partial denture can rest upon them without interfering with the way the patient bites the teeth together. Since they sit on the teeth, as well as being attached to them, they are extremely stable and retentive
The metal framework does not contact the gums. Thus, as the gums resorb, this type of partial does not sink with them and rarely requires relines.
|Rarely breaks. Can also be used for complete denture cases where breakage is a frequent problem.|
|It is made very thin, so less noticeable to tongue|
|More stable and retentive|
However a major drawback is the visibility of metal clasps which might be objectionable to some patients.
FLEXIBLE DENTURES (VALPLAST)
The most recent advance in dental materials has been the application of flexible materials for the fabrication of dental appliances. This material generally replaces the metal, and the pink acrylic denture material used to build the framework for standard removable partial dentures Flexible partial dentures are the comfortable, beautiful, and affordable choice
The flexibility, combined with strength and light weight, provides total comfort and great looks! It is nearly unbreakable, is colored pink like the gums, can be built quite thin, and can form not only the denture base, but the clasps as well.
The preparation is relatively simple because your natural teeth don't need to be altered in any way. The Valplast® partial is virtually invisible because there are no metal clasps and the material itself blends with the tissue in your mouth so that the only thing that shows is your beautiful smile.
Valplast® appliances are very durable and are designed to give long term performance under normal usage. Small accidents such as dropping the appliance in the sink or on the floor will not damage the Valplast®.
VALPLAST KEY BENEFITS ARE:
|Retention - flexes into a retentive position, below the undercut.|
|Comfort - thin, lightweight and flexible. |
|Esthetics-pink shades allow natural tissue tone to appear through material.|
|Strength - clinically unbreakable, more durable than acrylic and won't absorb stains or odors.|
|Ease - no tooth or tissue preparation is required so you can offer patients a conservative and pain-free solution|
|Allergies to conventional denture material|
|History of partial frame breakage |
|Alternative to implants or fixed products |
THE COMBINATION OF CAST PARTIAL AND VALPLAST PARTIAL DENTURE
A good alternative to the all-Valplast or a cast partial partial denture is one made with a combination cast metal framework with valplast clasps. This has the advantage of being tooth supported and also having gum colored plastic clasps like the Valplast partial.
This combination of metal framework and plastic clasp eliminates most of the difficulty of recurrent sore spots, since the framework resists movement and pressure from the clasps, while having the benefit of nearly invisible clasps.