There is an alternative to traditional direct restorations (fillings), that many patients are now choosing when the occlusal (chewing) surfaces of their back teeth need to be restored. This alternative is an indirect (laboratory fabricated), glass polymer restoration called an inlay/onlay. Inlay/onlay restorations look and function much like conventional fillings do, but their composition and linkage to your teeth offer benefits that standard direct restorations cannot match.
The inlay/onlay restorations that we employ here in the office are made of a material called glass polymer at a dental laboratory. Glass polymer is a combination of two commonly used substances in dentistry - ceramics and bonding (tooth colored filling material). They are fused together in the lab under extreme heat and pressure to produce a substance that is more durable than bonding and more tenacious than amalgam (silver) fillings. Other properties of glass polymer inlay/onlay restorations that make them superior to direct restorations for the chewing surfaces of your back teeth include better esthetics than even bonding and the ability to strengthen the restored tooth through adhesion.
A cracked tooth with a failing restoration...
Unlike a filling that is completed in one visit, two visits are required to restore your tooth with an inlay. At the first visit your tooth is prepared for the inlay in much the same way it would be for a filling. Instead of having the restoration placed in your tooth directly after preparation as with a filling, however, an impression of the prepared tooth is taken and then a provisional inlay is placed in your tooth. The impression is then sent to a dental laboratory where it is poured in stone to create a model of your teeth. The glass polymer inlay is then produced on this model and sent back to our office. At the second visit the provisional inlay is removed from your tooth and the glass polymer one is adhesively bonded into it.
...restored with a glass polymer inlay/onlay restoration for strength and beauty.
There are many advantages to this type of restoration for the chewing surfaces of your back teeth. The esthetics of glass polymer inlay/onlay restorations are far superior to silver fillings and can match the natural shade of your tooth even more closely than bonded ones. These inlay/onlay restorations are much more resistant to the heavy chewing pressure exerted on the occlusal surfaces of your back teeth than bonded fillings are and will therefore last appreciably longer. They are also not abrasive to the teeth they contact in your bite as some bonded fillings are that have been quartz-filled for extra strength. Because glass polymer inlay/onlay restorations are bonded in place, they will actually serve to strengthen your teeth against fracture through the melding of your tooth and the inlay. Silver fillings depend on mechanical (undercut) retention to stay in place and provide no adhesive binding of your tooth to resist fracture. In certain instances, inlay/onlay restorations can be a lower cost option for you than crowns in the prevention of tooth fracture. When bonded fillings are cured (set up) with an ultraviolet (blue) light, they shrink somewhat (about 3-4%). This is not critical at your front teeth which do not come under significant chewing forces. On the chewing surfaces of your back teeth these forces are so much greater that food particles can be driven into the tiny gaps left by this shrinkage causing marginal decay. Inlay/onlay restorations cured with heat and pressure do not shrink when adhesively bonded in place.
INLAY/ONLAYS OFFER ALL OF THE ABOVE BENEFITS AT ONLY A FRACTION OF THE COST OF A CROWN!