WHAT IS DENTAL BONDING
Bonding involves altering the tooth surface or the surface of a restorative material in such a way that the bonding agent actually becomes one with that material. With teeth this usually involves the application of an acid solution, sometimes weak and sometimes strong, that causes either physical or chemical changes to the surface allowing the bonding agent to unite with it. This is much different than luting agents or cements which act simply as glue, sticking to both sides of the union but remaining physically and chemically independent. Cements can be quite strong but in the mouth where the environment alternates between wet, dry, hot and cold, not to mention changes in pH (acidity) , exposure to various bacteria and the physical jarring teeth and restorative materials are subjected to during function they tend to break down and weaken over time. Bonds hold up much better under these conditions with the added benefit of being invisible. Plus because of their tenacity we can bond to smooth surfaces and small surface areas allowing us to be very conservative when shaping teeth to receive these restorations.
A BRIEF HISTORY OF BONDING IN DENTISTRY
Dental bonding had it's infancy way back in the 1950's. But back then, as with any new technology the process was of questionable value and the materials used were in their earliest stages of development. After many years of research and development the chemistry involved became much more sophisticated. Fast forward to the late 1970s when bonding and the cosmetic dentistry revolution began to gain momentum. Now dentists had a means of dramatically changing a persons appearance without having to severely cut down teeth to put crowns on them. At first the "stickyness" of the bond was only reliable when you were bonding to enamel. While to some degree this is still true the chemistry has evolved to where bonding to dentin is pretty reliable if not sometimes technique sensitive. Today we now enjoy "7th generation" bonding agents that are very predictable, easy to use and have few side effects such as tooth sensitivity that plagued some of the earlier generations. While newer isn't necessarily better I 'm sure the "8th generation " of these materials is only around the corner. As bonds have improved our ability to use this technology has expanded and our ability to bond different materials has increased. Now bonding is or can be used for almost any type of restorative dentistry.
WHERE IS BONDING USED? WHAT ARE THE ADVANTAGES AND DISADVANTAGES?
Bonding can be used in almost any phase of dentistry. All tooth colored fillings,inlays, onlays and veneers are bonded not only to make them adhere but is required for strength of these restorations. Things like porcelain veneers are often made of materials that are quite fragile but once bonded to the teeth become very strong. Bonding is often used to cement crowns. In this case the advantages are not only strength but also reduced sensitivity and insolubility which is a big advantage. Many of the older cements,even though they worked quite well could break down over the long term in the oral environment. Bonds can also break down over time but the materials themselves are relatively insoluble so still give a measure of protection against the restoration becoming loose. Bonding with composite resin is also used to adhere orthodontic brackets to the teeth and bonding agents can be used to cover sensitive root surfaces. When composite resin fillings are bonded to the outside of teeth the minimum amount of tooth structure can be removed and being more conservative is almost always better. Bonded composite resin can be used to fill decay, repair chipped, warn or broken teeth and to close spaces. The shape and sometimes color of teeth can be dramatically changed using these materials as well at far less cost than crowns or veneers. Generally speaking bonded composite resin is the least expensive way to make dramatic changes to your smile. Composite fillings do have their limitations though. They are not as strong or as long lasting as porcelain and except in the most expert of hands are not quite as good looking though they can still be quite beautiful. They also can stain over time, especially around the edges. Aside from lower cost to place they are also less costly and easier to repair.
HOW LONG DOES BONDING LAST?
This again depends on the application. When you are speaking of bonded crowns or veneers we can expect the bond in to last 10 or more years as long as there are no extenuating circumstances such as decay or severe teeth grinding habits. When it comes to fillings, closing spaces and adding onto teeth to change their shape 3 to 10 years is a reasonable expectation again as long as there are no significant other factors involved. Again though, repairs are often very easy, quick and low in cost. Every situation is different so if you have some history with your dentist and they know your habits and tendencies then they may be more likely to give you a prediction on how long the restorations might be expected to last in your mouth.
Bonded restorations are extremely versatile, good looking and can have a dramatic effect on the way you look and feel about yourself. Almost any cosmetic change you are looking to achieve will likely involve bonding whether it's simple fillings, orthodontics, or a mouth full of veneers or crowns. Please go to my GALLERY tab to view photos all of the things I've discussed above.
Dr Gold has been practicing general cosmetic and full mouth rehabilitation dentistry in the Capital District of upstate New York for 32 years.